Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripher...Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.展开更多
The conversion and storage of photothermal energy using phase change materials(PCMs)represent an optimal approach for harnessing clean and sustainable solar energy.Herein,we encapsulated polyethylene glycol(PEG)in mon...The conversion and storage of photothermal energy using phase change materials(PCMs)represent an optimal approach for harnessing clean and sustainable solar energy.Herein,we encapsulated polyethylene glycol(PEG)in montmorillonite aerogels(3D-Mt)through vacuum impregnation to prepare 3D-Mt/PEG composite PCMs.When used as a support matrix,3D-Mt can effectively prevent PEG leakage and act as a flame-retardant barrier to reduce the flammability of PEG.Simultaneously,3D-Mt/PEG demonstrates outstanding shape retention,increased thermal energy storage density,and commendable thermal and chemical stability.The phase transition enthalpy of 3D-Mt/PEG can reach 167.53 J/g and remains stable even after 50 heating-cooling cycles.Furthermore,the vertical sheet-like structure of 3D-Mt establishes directional heat transport channels,facilitating efficient phonon transfer.This configuration results in highly anisotropic thermal conductivities that ensure swift thermal responses and efficient heat conduction.This study addresses the shortcomings of PCMs,including the issues of leakage and inadequate flame retardancy.It achieves the development and design of 3D-Mt/PEG with ultrahigh strength,superior flame retardancy,and directional heat transfer.Therefore,this work offers a design strategy for the preparation of high-performance composite PCMs.The 3D-Mt/PEG with vertically aligned and well-ordered array structure developed in this research shows great potential for thermal management and photothermal conversion applications.展开更多
BACKGROUND Adequate bowel preparation is critical for colonoscopy screening.At present,the most widely used intestinal cleaner recommended at home and abroad is Polyethylene glycol(PEG).Intestinal cleansers can cause ...BACKGROUND Adequate bowel preparation is critical for colonoscopy screening.At present,the most widely used intestinal cleaner recommended at home and abroad is Polyethylene glycol(PEG).Intestinal cleansers can cause electrolyte disturbances and hyponatremia.However,hyponatremic encephalopathy due to hyponatremia induced by PEG solution,although rare,can lead to serious irreversible sequelae and even death.CASE SUMMARY In this report,we discuss a case of neurological dysfunction due to hyponatremia,also known as hyponatremic encephalopathy,observed in a 63-year-old woman who underwent PEG-based bowel preparation for colonoscopy.She was eventually transferred to our intensive care unit for treatment due to her Glasgow Coma Scale score of 9/15(Eye opening 2;Verbal response 1;Motor response 6)and abnormal laboratory tests.CONCLUSION Physicians should be thoroughly familiarized with the patient’s history before prescribing PEG for bowel preparation,and timely identification of patients with hyponatremic encephalopathy is essential as delayed treatment is associated with poor neurological outcomes.An intravenous infusion of 3%sodium chloride is recommended at the onset of early symptoms.The goal of treatment is to adequately treat cerebral edema while avoiding serum sodium correction beyond 15 to 20 m Eq/L within 48 h of treatment to prevent osmotic demyelination syndrome.展开更多
Background: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to eva...Background: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to evaluate the cytotoxicity and angiogenesis of polyethylene glycol(PEG) crosslinked decellularized single liver lobe scaffolds(DLSs), and establish its suitability as a graft for long-term liver tissue engineering. Methods: Using mercaptoacrylate produced by the Michael addition reaction, DLSs were first modified using N-succinimidyl S-acetylthioacetate(SATA), followed by cross-linking with PEG as well as vascular endothelial growth factor(VEGF). The optimal concentration of agents and time of the individual steps were identified in this procedure through biomechanical testing and morphological analysis. Subsequently, human umbilical vein endothelial cells(HUVECs) were seeded on the PEG crosslinked scaffolds to detect the proliferation and viability of cells. The scaffolds were then transplanted into the subcutaneous tissue of Sprague-Dawley rats to evaluate angiogenesis. In addition, the average number of blood vessels was evaluated in the grafts with or without PEG at days 7, 14, and 21 after implantation. Results: The PEG crosslinked DLS maintained their three-dimensional structure and were more translucent after decellularization than native DLS, which presented a denser and more porous network structure. The results for Young’s modulus proved that the mechanical properties of 0.5 PEG crosslinked DLS were the best and close to that of native livers. The PEG-VEGF-DLS could better promote cell proliferation and differentiation of HUVECs compared with the groups without PEG cross-linking. Importantly, the average density of blood vessels was higher in the PEG-VEGF-DLS than that in other groups at days 7, 14, and 21 after implantation in vivo. Conclusions: The PEG crosslinked DLS with VEGF could improve the biomechanical properties of native DLS, and most importantly, their lack of cytotoxicity provides a new route to promote the proliferation of cells in vitro and angiogenesis in vivo in liver tissue engineering.展开更多
BACKGROUND Polyethylene glycol(PEG)is widely used as an additive because of its hydrophilic and chemically inert properties.However,there are been increasing reports of PEG allergies,including anaphylaxis,although the...BACKGROUND Polyethylene glycol(PEG)is widely used as an additive because of its hydrophilic and chemically inert properties.However,there are been increasing reports of PEG allergies,including anaphylaxis,although they are still rare.This case report aims to raise awareness,that the commonly used bowel cleansing agent containing PEG can cause serious allergic reactions.CASE SUMMARY Prior to surgery for sigmoid colon cancer,a 63-year-old man was prescribed a bowel cleansing agent containing PEG.Within 30 min of ingestion,he developed symptoms of anaphylactic shock and did not respond to initial intramuscular epinephrine injection.Under diagnosis of anaphylaxis to PEG,he was stabilized with fluid hydration and continuous norepinephrine infusion.CONCLUSION While allergic reactions to PEG are rare,they can be life-threatening.Therefore,it is crucial for clinicians to be aware of this possibility and to diagnose and resuscitate patients immediately.展开更多
The Knoevenagel condensation of aromatic aldehydes with active methylene compound proceeded efficiently in polyethylene glycol at room temperature with L-proline as catalyst. The yield is high and the products had E-i...The Knoevenagel condensation of aromatic aldehydes with active methylene compound proceeded efficiently in polyethylene glycol at room temperature with L-proline as catalyst. The yield is high and the products had E-isomer dominantly. Polyethylene glycol containing L-proline could be recycled and reused for several times without noticeably decreasing in productivity.展开更多
Current Neuroscience dogma holds that transections or ablations of a segment of peripheral nerves produce: (1) Immediate loss of axonal continuity, sensory signaling, and motor control; (2) Wallerian rapid (1-3 ...Current Neuroscience dogma holds that transections or ablations of a segment of peripheral nerves produce: (1) Immediate loss of axonal continuity, sensory signaling, and motor control; (2) Wallerian rapid (1-3 days) degeneration of severed distal axons, muscle atrophy, and poor behavioral recovery after many months (if ever, after ablations) by slowly-regenerating (1 mm/d), proximal-stump outgrowths that must specifically reinnervate denervated targets; (3) Poor acceptance of microsutured nerve allografts, even if tissue-matched and immune-suppressed. Repair of transections/ablations by neurorrhaphy and well-specified-sequences of PEG-fusion solutions (one containing polyethylene glycol, PEG) successfully address these problems. However, conundrums and confusions regarding unorthodox and dramatic results of PEG-fusion repair in animal model systems often lead to misunderstandings. For example, (1) Axonal continuity and signaling is re-established within minutes by non-specifically PEG-fusing (connecting) severed motor and sensory axons across each lesion site, but remarkable behavioral recovery to near-unoperated levels takes several weeks; (2) Many distal stumps of inappropriately-reconnected, PEG-fused axons do not ever (Wallerian) degenerate and continuously innervate muscle fibers that undergo much less atrophy than otherwise-denervated muscle fibers; (3) Host rats do not reject PEG-fused donor nerve allografts in a non-immuno-privileged environment with no tissue matching or immunosuppression; (4) PEG fuses apposed open axonal ends or seals each shut (thereby preventing PEG-fusion), depending on the experimental protocol; (5) PEG-fusion protocols produce similar results in animal model systems and early human case studies. Hence, iconoclastic PEG-fusion data appropriately understood might provoke a re-thinking of some Neuroscience dogma and a paradigm shift in clinical treatment of peripheral nerve injuries.展开更多
AIM To study tumor response, and tolerability of arterially directed embolic therapy(ADET) with polyethylene glycol embolics loaded with irinotecan for the treatment of colorectal cancer liver metastases(CRC-LM). Seco...AIM To study tumor response, and tolerability of arterially directed embolic therapy(ADET) with polyethylene glycol embolics loaded with irinotecan for the treatment of colorectal cancer liver metastases(CRC-LM). Secondary objectives were to monitor quality of life, time to progression and survival of patients.METHODS Patients were included in the study if they were affected by CRC-LM, refractory to systemic chemotherapy, treated with ADET using polyethylene glycol embolics, and had liver involvement < 50%. Tumor response, performance status(PS), tumor marker antigens, and quality of life(QoL) were monitored at 1, 3 and 6 mo after ADET. QoL was assessed with the Palliative Performance Scale(PPS).RESULTS We treated 50 consecutive CRC-LM patients with ADET using polyethylene glycol embolics. Their tumor response one month after ADET was: 28% of complete response(CR), 48% of partial response(PR), 8% stable disease(SD), and 16% of progression. Tumor response 3 mo after ADET was CR 24%, PR 38%, SD 19% and progression disease(PD) 19%. Tumor response 6 mo after ADET was CR 18%, PR 44%, SD 21% and PD 18%. QoL was 90% PPS at each time point. Median time to progression for patients who progressed was 2.5 mo(range 0.8-6). Median follow-up was 14 mo(0.8-25 range). ADETs were performed with no complications. Observed side effects(mild or moderate intensity) were: Pain in 32% of patients, increase of transaminase levels in 20% and fever in 14%, whereas 30% of patients did not complain any adverse event. CONCLUSION The treatment of unresectable CRC-LM with ADET using polyethylene glycol microspheres loaded with irinotecan was effective in tumor response and resulted in mild toxicity, and good QoL.展开更多
BACKGROUND Efficient bowel cleansing is essential for a successful colonoscopy,but the ideal cleansing agent,volume,and pharmaceutical dosage form have yet to be determined.Small-volume cleansers enhance patient compl...BACKGROUND Efficient bowel cleansing is essential for a successful colonoscopy,but the ideal cleansing agent,volume,and pharmaceutical dosage form have yet to be determined.Small-volume cleansers enhance patient compliance.AIM To compare the bowel cleansing efficacy of 32-tablet sodium phosphate(Quiklean®)with 2-L polyethylene glycol(PEG)/bisacodyl(Klean-Prep/Dulcolax®)under identical dietary recommendations.METHODS This multicenter,randomized,parallel-group,noninferiority clinical trial enrolled 472 outpatients,randomized 456 subjects,and scheduled 442 subjects to undergo colonoscopy(Quiklean®=222 and Klean-Prep/Dulcolax®=220).After bowel preparation,a colonoscopist performed the colonoscopy with video recorded for rating.The primary efficacy endpoint was the bowel cleansing quality using the Aronchick Scale.The secondary endpoints were the bowel cleansing efficacy of three colon segments,tolerability and acceptability,safety using the Ottawa bowel preparation scale,questionnaires by subjects,and monitoring of adverse events.RESULTS Success rates(Excellent+Good)of the bowel cleansing quality by Aronchick Scale were 98.6%(n=205)and 97.6%(n=204)in the Quiklean®and Klean-Prep/Dulcolax®groups,respectively.Quiklean®demonstrated noninferiority over Klean-Prep/Dulcolax®in colon cleansing efficacy.Quicken showed better tolerability and acceptability in the overall experience(was rated as excellent;24.0%vs 17.2%;P=0.0016)and the taste of the study preparation(was rated as excellent,23.1%vs 13.4%;P<0.0001)than Klean-Prep/Dulcolax®.Safety profiles did not differ between the two groups.Our data indicate that Quiklean®is an adequate,well-tolerated bowel cleansing preparation compared with the standard comparator Klean-Prep/Dulcolax®.CONCLUSION Quiklean®is sodium phosphate tablets available on Taiwan’s market for bowel preparation;it potentially offers patients an alternative to standard large-volume bowel preparation regimens and may,therefore,increase positive attitudes toward colonoscopies and participation rates.展开更多
This paper gives a brief report of the synthesis of a new kind of solid-solid phase change materials (SSPCMs), nano-crystalline cellulose/polyethylene glycol (NCC/PEG). These PCMs have very high ability for energy...This paper gives a brief report of the synthesis of a new kind of solid-solid phase change materials (SSPCMs), nano-crystalline cellulose/polyethylene glycol (NCC/PEG). These PCMs have very high ability for energy storage, and their enthalpies reach 103.8 J/g. They are composed of two parts, PEG as functional branches for energy storage, and NCC as skeleton. The flexible polymer PEG was grafted onto the surface of rigid powder of NCC by covalent bonds. The results of DSC, FT-IR were briefly introduced, and some comments were also given.展开更多
Mica was used as a supporting matrix for composite phase change materials(PCMs)in this work because of its distinctive morphology and structure.Composite PCMs were prepared using the vacuum impregnation method,in whic...Mica was used as a supporting matrix for composite phase change materials(PCMs)in this work because of its distinctive morphology and structure.Composite PCMs were prepared using the vacuum impregnation method,in which mica served as the supporting material and polyethylene glycol(PEG)served as the PCM.Fourier transform infrared and X-ray diffraction analysis confirmed that the addition of PEG had no effect on the crystal structure of mica.Moreover,no chemical reaction occurred between PEG and mica during the vacuum impregnation process,and no new substance was formed.The maximum load of mica-stabilized PEG was 46.24%,the phase change temperature of M_(400)/PEG was 46.03℃,and the latent heat values of melting and cooling were 77.75 and 77.73 J·g^(−1),respectively.The thermal conductivity of M_(400)/PEG was 2.4 times that of pure PEG.The thermal infrared images indicated that the thermal response of M_(400)/PEG improved relative to that of pure PEG.The leakage test confirmed that mica could stabilize PEG and that M_(400)/PEG had great form-stabilized property.These results demonstrate that M_(400)/PEG has potential in the field of building energy conservation.展开更多
Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol(mPEG-OH), which contained a hydroxyl group combining with hex...Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol(mPEG-OH), which contained a hydroxyl group combining with hexamethylene diisocyanate(HDI) to form a novel macromonomer namely monomethoxy polyethylene glycol isocyanate(mPEG-NCO) containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted copolymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG- NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The experimental result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling degree in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.展开更多
Complete transection of peripheral mixed nerves immediately produces loss of sensory perception,muscle contractions and voluntary behavior mediated by the severed distal axons.In contrast to natural regeneration(~1 mm...Complete transection of peripheral mixed nerves immediately produces loss of sensory perception,muscle contractions and voluntary behavior mediated by the severed distal axons.In contrast to natural regeneration(~1 mm/d)of proximal axons that may eventually reinnervate denervated targets,re-innervation is restored within minutes by PEG-fusion that consists of neurorrhaphy and a sequence of well specified hypo-and isotonic calcium-free or calcium-containing solutions,the anti-oxidant methylene blue(MB)and the membrane fusogen polyethylene glycol(PEG).In this study,we examined the relative efficacy of PEG-fusion with no MB(0%),0.5%MB,or 1%MB on the recovery of voluntary behaviors by female Sprague-Dawley rats with a complete mid-thigh severance of their sciatic nerve bathed in extracellular fluid or calcium-containing isotonic saline.The recovery of voluntary behaviors is the most relevant measure of success of any technique to repair peripheral nerve injuries.We assessed recovery by the sciatic functional index,a commonly used measure of voluntary hindlimb behaviors following complete sciatic transections.We reported that both 1%MB and 0.5%MB in sterile distilled water in our PEG-fusion protocol with neurorrhaphy significantly increased the rate and extent of behavioral recovery compared to PEG plus neurorrhaphy alone.Furthermore,0.5%MB was as effective as 1%MB in voluntary behavioral recovery as assessed by the sciatic functional index.Since sterile 1%MB is no longer clinically available,we therefore recommend that 0.5%MB be included in upcoming human clinical trials to evaluate the safety and efficacy of PEG-fusion.All animal procedures were approved by the University of Texas Institutional Animal Care and Use Committee(AUP-2019-00225)on September 9,2020.展开更多
Mud shale hydration and swelling are major challenges in the development of water-based drilling fuids(WBDFs).In this work,the inhibition performance and inhibition mechanism of polyethylene glycol(PEG)and potassium c...Mud shale hydration and swelling are major challenges in the development of water-based drilling fuids(WBDFs).In this work,the inhibition performance and inhibition mechanism of polyethylene glycol(PEG)and potassium chloride(KCl)were investigated by hot rolling recovery tests,linear swell tests,Fourier transform infrared spectroscopy,X-ray difraction,atomic absorption spectrophotometry and X-ray photoelectron spectroscopy.The experimental results show that the combination of PEG and KCl achieved higher recovery and lower linear swelling rate than those obtained by individual PEG or KCl.Compared to the d-spacing of Na-montmorillonite(Na-Mt)with PEG or KCl,the d-spacing of Na-Mt with PEG+KCl was lower,which indicates that KCl and PEG have synergistic inhibition efect.This synergistic efect can replace sodium ions and water molecules from the interlayer space of Na-Mt and decrease the d-spacing of Na-Mt.Based on the above experimental results and analysis,a method for optimizing PEG and KCl concentrations was proposed and further verifed by rheological and hot rolling recovery tests of WBDFs.Hence,the results of this work can provide valuable theoretical guidance for developing other synergistic inhibitors.展开更多
BACKGROUND Acute pancreatitis(AP)is a sudden inflammatory process of the pancreas that may also involve surrounding tissues and/or remote organs.Inflammation and parenchymal cell death are common pathological features...BACKGROUND Acute pancreatitis(AP)is a sudden inflammatory process of the pancreas that may also involve surrounding tissues and/or remote organs.Inflammation and parenchymal cell death are common pathological features of this condition and determinants of disease severity.Polyethylene glycols(PEGs)are nonimmunogenic,non-toxic water-soluble polymers widely used in biological,chemical,clinical and pharmaceutical settings.AIM To evaluate the protective effect of a 35-kDa molecular weight PEG(PEG35)on the pancreatic damage associated to cerulein-induced acute pancreatitis in vivo and in vitro.METHODS Wistar rats were assigned at random to a control group,a cerulein–induced AP group and a PEG35 treatment group.AP was induced by five hourly intraperitoneal injections of cerulein(50μg/kg/bw),while the control animals received saline solution.PEG35 was administered intraperitoneally 10 minutes before each cerulein injection in a dose of 10 mg/kg.After AP induction,samples of pancreatic tissue and blood were collected for analysis.AR42J pancreatic acinar cells were treated with increasing concentrations of PEG35 prior to exposure with tumor necrosis factorα(TNFα),staurosporine or cerulein.The severity of AP was determined on the basis of plasma levels of lipase,lactate dehydrogenase activity,pancreatic edema and histological changes.To evaluate the extent of the inflammatory response,the gene expression of inflammation-associated markers was determined in the pancreas and in AR42J-treated cells.Inflammation-induced cell death was also measured in models of in vivo and in vitro pancreatic damage.RESULTS Administration of PEG35 significantly improved pancreatic damage through reduction on lipase levels and tissue edema in cerulein-induced AP rats.The increased associated inflammatory response caused by cerulein administration was attenuated by a decrease in the gene expression of inflammation-related cytokines and inducible nitric oxide synthase enzyme in the pancreas.In contrast,pancreatic tissue mRNA expression of interleukin 10 was markedly increased.PEG35 treatment also protected against inflammation-induced cell death by attenuating lactate dehydrogenase activity and modulating the pancreatic levels of apoptosis regulator protein BCL-2 in cerulein hyperstimulated rats.Furthermore,the activation of pro-inflammatory markers and inflammationinduced cell death in pancreatic acinar cells treated with TNFα,cerulein or staurosporine was significantly reduced by PEG35 treatment,in a dose-dependent manner.CONCLUSION PEG35 ameliorates pancreatic damage in cerulein-induced AP and AR42J-treated cells through the attenuation of the inflammatory response and associated cell death.PEG35 may be a valuable option in the management of AP.展开更多
D-a-tocopherol polyethylene glycol 1000 succinate(TPGS)is a pharmaceutical excipient approved by Chinese NMPA and FDA of USA.It's widely applied as a multifunctional drug carrier for nanomedicine.The advantages of...D-a-tocopherol polyethylene glycol 1000 succinate(TPGS)is a pharmaceutical excipient approved by Chinese NMPA and FDA of USA.It's widely applied as a multifunctional drug carrier for nanomedicine.The advantages of TPGS include P-glycoprotein(P-gp)inhibition,penetration promotion,apoptosis induction via mitochondrial-associated apoptotic pathways,multidrug resistant(MDR)reversion,metastasis inhibition and so on.TPGS-based drug delivery systems which are responding to extermal stimulus can combine the inhibitory functions of TPGS towards P-gp with the environmentally responsive controlled release property and thus exerts a synergistic anti-cancer effect,through increased intracellular drug concentration in tumors cells and well-controlled drug release behavior.In this review,TPGS-based nano-sized delivery systems responsive to different stimuli were summarized and discussed,including pH-responsive,redox-responsive and multi-responsive systems in various formulations.The achievements,mechanisms and diffcrent characteristics of TPGS-bascd stimuli-responsive drug-delivery systems in tumor therapy were also outlined.展开更多
Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacteri...Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fiuorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.展开更多
Polyethylene glycol(PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In...Polyethylene glycol(PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays(MEA) were used to measure mean firing rate(MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups(P 〈 0.01, P 〈 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.展开更多
The catalyst boron trifluoride etherate was used to catalyze the reaction of epoxy resin with polyethylene glycol (PEG), and the effect of the concentration of the catalyst on the reaction is studied. It is shown that...The catalyst boron trifluoride etherate was used to catalyze the reaction of epoxy resin with polyethylene glycol (PEG), and the effect of the concentration of the catalyst on the reaction is studied. It is shown that there exist two competitive reactions : I, self polymerization of epoxy resin via chain growth and II, copolymerization of epoxy resin with PEG via step growth. At high concentration of the catalyst reaction I dominates and reaction II is negligible. On the contrary, at low concentration of the catalyst, reaction II dominates and block copolymers are formed In the intermediate case, the two reactions are comparable with the result that a gel structure is obtained.展开更多
The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameter...The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG 1000 under 5 MPa of CO2 and 2 MPa of O2 at 100 ℃ for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.展开更多
基金supported by grants from the Lone Star Paralysis Foundation,NIH R01NS081063Department of Defense award W81XWH-19-2-0054 to GDB+2 种基金supported by University of Wyoming Startup funds,Department of Defense grant W81XWH-17-1-0402the University of Wyoming Sensory Biology COBRE under National Institutes of Health(NIH)award number 5P20GM121310-02the National Institute of General Medical Sciences of the NIH under award number P20GM103432 to JSB。
文摘Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.
基金supported by the National Natural Science Foundation of China(No.52104265)。
文摘The conversion and storage of photothermal energy using phase change materials(PCMs)represent an optimal approach for harnessing clean and sustainable solar energy.Herein,we encapsulated polyethylene glycol(PEG)in montmorillonite aerogels(3D-Mt)through vacuum impregnation to prepare 3D-Mt/PEG composite PCMs.When used as a support matrix,3D-Mt can effectively prevent PEG leakage and act as a flame-retardant barrier to reduce the flammability of PEG.Simultaneously,3D-Mt/PEG demonstrates outstanding shape retention,increased thermal energy storage density,and commendable thermal and chemical stability.The phase transition enthalpy of 3D-Mt/PEG can reach 167.53 J/g and remains stable even after 50 heating-cooling cycles.Furthermore,the vertical sheet-like structure of 3D-Mt establishes directional heat transport channels,facilitating efficient phonon transfer.This configuration results in highly anisotropic thermal conductivities that ensure swift thermal responses and efficient heat conduction.This study addresses the shortcomings of PCMs,including the issues of leakage and inadequate flame retardancy.It achieves the development and design of 3D-Mt/PEG with ultrahigh strength,superior flame retardancy,and directional heat transfer.Therefore,this work offers a design strategy for the preparation of high-performance composite PCMs.The 3D-Mt/PEG with vertically aligned and well-ordered array structure developed in this research shows great potential for thermal management and photothermal conversion applications.
文摘BACKGROUND Adequate bowel preparation is critical for colonoscopy screening.At present,the most widely used intestinal cleaner recommended at home and abroad is Polyethylene glycol(PEG).Intestinal cleansers can cause electrolyte disturbances and hyponatremia.However,hyponatremic encephalopathy due to hyponatremia induced by PEG solution,although rare,can lead to serious irreversible sequelae and even death.CASE SUMMARY In this report,we discuss a case of neurological dysfunction due to hyponatremia,also known as hyponatremic encephalopathy,observed in a 63-year-old woman who underwent PEG-based bowel preparation for colonoscopy.She was eventually transferred to our intensive care unit for treatment due to her Glasgow Coma Scale score of 9/15(Eye opening 2;Verbal response 1;Motor response 6)and abnormal laboratory tests.CONCLUSION Physicians should be thoroughly familiarized with the patient’s history before prescribing PEG for bowel preparation,and timely identification of patients with hyponatremic encephalopathy is essential as delayed treatment is associated with poor neurological outcomes.An intravenous infusion of 3%sodium chloride is recommended at the onset of early symptoms.The goal of treatment is to adequately treat cerebral edema while avoiding serum sodium correction beyond 15 to 20 m Eq/L within 48 h of treatment to prevent osmotic demyelination syndrome.
基金supported by grants from Natural Science Foundation of Zhejiang Province (LY20H180011)National Natural Science Foundation of China (81970653)Medical and Health Science and Technology project of Zhejiang (2016KYA061)
文摘Background: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to evaluate the cytotoxicity and angiogenesis of polyethylene glycol(PEG) crosslinked decellularized single liver lobe scaffolds(DLSs), and establish its suitability as a graft for long-term liver tissue engineering. Methods: Using mercaptoacrylate produced by the Michael addition reaction, DLSs were first modified using N-succinimidyl S-acetylthioacetate(SATA), followed by cross-linking with PEG as well as vascular endothelial growth factor(VEGF). The optimal concentration of agents and time of the individual steps were identified in this procedure through biomechanical testing and morphological analysis. Subsequently, human umbilical vein endothelial cells(HUVECs) were seeded on the PEG crosslinked scaffolds to detect the proliferation and viability of cells. The scaffolds were then transplanted into the subcutaneous tissue of Sprague-Dawley rats to evaluate angiogenesis. In addition, the average number of blood vessels was evaluated in the grafts with or without PEG at days 7, 14, and 21 after implantation. Results: The PEG crosslinked DLS maintained their three-dimensional structure and were more translucent after decellularization than native DLS, which presented a denser and more porous network structure. The results for Young’s modulus proved that the mechanical properties of 0.5 PEG crosslinked DLS were the best and close to that of native livers. The PEG-VEGF-DLS could better promote cell proliferation and differentiation of HUVECs compared with the groups without PEG cross-linking. Importantly, the average density of blood vessels was higher in the PEG-VEGF-DLS than that in other groups at days 7, 14, and 21 after implantation in vivo. Conclusions: The PEG crosslinked DLS with VEGF could improve the biomechanical properties of native DLS, and most importantly, their lack of cytotoxicity provides a new route to promote the proliferation of cells in vitro and angiogenesis in vivo in liver tissue engineering.
文摘BACKGROUND Polyethylene glycol(PEG)is widely used as an additive because of its hydrophilic and chemically inert properties.However,there are been increasing reports of PEG allergies,including anaphylaxis,although they are still rare.This case report aims to raise awareness,that the commonly used bowel cleansing agent containing PEG can cause serious allergic reactions.CASE SUMMARY Prior to surgery for sigmoid colon cancer,a 63-year-old man was prescribed a bowel cleansing agent containing PEG.Within 30 min of ingestion,he developed symptoms of anaphylactic shock and did not respond to initial intramuscular epinephrine injection.Under diagnosis of anaphylaxis to PEG,he was stabilized with fluid hydration and continuous norepinephrine infusion.CONCLUSION While allergic reactions to PEG are rare,they can be life-threatening.Therefore,it is crucial for clinicians to be aware of this possibility and to diagnose and resuscitate patients immediately.
文摘The Knoevenagel condensation of aromatic aldehydes with active methylene compound proceeded efficiently in polyethylene glycol at room temperature with L-proline as catalyst. The yield is high and the products had E-isomer dominantly. Polyethylene glycol containing L-proline could be recycled and reused for several times without noticeably decreasing in productivity.
文摘Current Neuroscience dogma holds that transections or ablations of a segment of peripheral nerves produce: (1) Immediate loss of axonal continuity, sensory signaling, and motor control; (2) Wallerian rapid (1-3 days) degeneration of severed distal axons, muscle atrophy, and poor behavioral recovery after many months (if ever, after ablations) by slowly-regenerating (1 mm/d), proximal-stump outgrowths that must specifically reinnervate denervated targets; (3) Poor acceptance of microsutured nerve allografts, even if tissue-matched and immune-suppressed. Repair of transections/ablations by neurorrhaphy and well-specified-sequences of PEG-fusion solutions (one containing polyethylene glycol, PEG) successfully address these problems. However, conundrums and confusions regarding unorthodox and dramatic results of PEG-fusion repair in animal model systems often lead to misunderstandings. For example, (1) Axonal continuity and signaling is re-established within minutes by non-specifically PEG-fusing (connecting) severed motor and sensory axons across each lesion site, but remarkable behavioral recovery to near-unoperated levels takes several weeks; (2) Many distal stumps of inappropriately-reconnected, PEG-fused axons do not ever (Wallerian) degenerate and continuously innervate muscle fibers that undergo much less atrophy than otherwise-denervated muscle fibers; (3) Host rats do not reject PEG-fused donor nerve allografts in a non-immuno-privileged environment with no tissue matching or immunosuppression; (4) PEG fuses apposed open axonal ends or seals each shut (thereby preventing PEG-fusion), depending on the experimental protocol; (5) PEG-fusion protocols produce similar results in animal model systems and early human case studies. Hence, iconoclastic PEG-fusion data appropriately understood might provoke a re-thinking of some Neuroscience dogma and a paradigm shift in clinical treatment of peripheral nerve injuries.
文摘AIM To study tumor response, and tolerability of arterially directed embolic therapy(ADET) with polyethylene glycol embolics loaded with irinotecan for the treatment of colorectal cancer liver metastases(CRC-LM). Secondary objectives were to monitor quality of life, time to progression and survival of patients.METHODS Patients were included in the study if they were affected by CRC-LM, refractory to systemic chemotherapy, treated with ADET using polyethylene glycol embolics, and had liver involvement < 50%. Tumor response, performance status(PS), tumor marker antigens, and quality of life(QoL) were monitored at 1, 3 and 6 mo after ADET. QoL was assessed with the Palliative Performance Scale(PPS).RESULTS We treated 50 consecutive CRC-LM patients with ADET using polyethylene glycol embolics. Their tumor response one month after ADET was: 28% of complete response(CR), 48% of partial response(PR), 8% stable disease(SD), and 16% of progression. Tumor response 3 mo after ADET was CR 24%, PR 38%, SD 19% and progression disease(PD) 19%. Tumor response 6 mo after ADET was CR 18%, PR 44%, SD 21% and PD 18%. QoL was 90% PPS at each time point. Median time to progression for patients who progressed was 2.5 mo(range 0.8-6). Median follow-up was 14 mo(0.8-25 range). ADETs were performed with no complications. Observed side effects(mild or moderate intensity) were: Pain in 32% of patients, increase of transaminase levels in 20% and fever in 14%, whereas 30% of patients did not complain any adverse event. CONCLUSION The treatment of unresectable CRC-LM with ADET using polyethylene glycol microspheres loaded with irinotecan was effective in tumor response and resulted in mild toxicity, and good QoL.
基金The China Medical University Hospital,No.DMR-108-125.
文摘BACKGROUND Efficient bowel cleansing is essential for a successful colonoscopy,but the ideal cleansing agent,volume,and pharmaceutical dosage form have yet to be determined.Small-volume cleansers enhance patient compliance.AIM To compare the bowel cleansing efficacy of 32-tablet sodium phosphate(Quiklean®)with 2-L polyethylene glycol(PEG)/bisacodyl(Klean-Prep/Dulcolax®)under identical dietary recommendations.METHODS This multicenter,randomized,parallel-group,noninferiority clinical trial enrolled 472 outpatients,randomized 456 subjects,and scheduled 442 subjects to undergo colonoscopy(Quiklean®=222 and Klean-Prep/Dulcolax®=220).After bowel preparation,a colonoscopist performed the colonoscopy with video recorded for rating.The primary efficacy endpoint was the bowel cleansing quality using the Aronchick Scale.The secondary endpoints were the bowel cleansing efficacy of three colon segments,tolerability and acceptability,safety using the Ottawa bowel preparation scale,questionnaires by subjects,and monitoring of adverse events.RESULTS Success rates(Excellent+Good)of the bowel cleansing quality by Aronchick Scale were 98.6%(n=205)and 97.6%(n=204)in the Quiklean®and Klean-Prep/Dulcolax®groups,respectively.Quiklean®demonstrated noninferiority over Klean-Prep/Dulcolax®in colon cleansing efficacy.Quicken showed better tolerability and acceptability in the overall experience(was rated as excellent;24.0%vs 17.2%;P=0.0016)and the taste of the study preparation(was rated as excellent,23.1%vs 13.4%;P<0.0001)than Klean-Prep/Dulcolax®.Safety profiles did not differ between the two groups.Our data indicate that Quiklean®is an adequate,well-tolerated bowel cleansing preparation compared with the standard comparator Klean-Prep/Dulcolax®.CONCLUSION Quiklean®is sodium phosphate tablets available on Taiwan’s market for bowel preparation;it potentially offers patients an alternative to standard large-volume bowel preparation regimens and may,therefore,increase positive attitudes toward colonoscopies and participation rates.
文摘This paper gives a brief report of the synthesis of a new kind of solid-solid phase change materials (SSPCMs), nano-crystalline cellulose/polyethylene glycol (NCC/PEG). These PCMs have very high ability for energy storage, and their enthalpies reach 103.8 J/g. They are composed of two parts, PEG as functional branches for energy storage, and NCC as skeleton. The flexible polymer PEG was grafted onto the surface of rigid powder of NCC by covalent bonds. The results of DSC, FT-IR were briefly introduced, and some comments were also given.
基金This work was financially supported by the National Nat-ural Science Foundation of China(Nos.51874047 and 51504041)the Special Fund for the Construction of Innovat-ive Provinces in Hunan Province,China(No.2020RC3038)+2 种基金the Changsha City Fund for Distinguished and Innovative Young Scholars,China(No.kq1802007)the Fund for Uni-versity Young Core Instructors of Hunan Province,China,the Innovation Program for Postgraduate of Changsha Uni-versity of Science and Technology,Chinathe Outstand-ing Youth Project of Hunan Provincial Department of Educa-tion,China(No.18B148).
文摘Mica was used as a supporting matrix for composite phase change materials(PCMs)in this work because of its distinctive morphology and structure.Composite PCMs were prepared using the vacuum impregnation method,in which mica served as the supporting material and polyethylene glycol(PEG)served as the PCM.Fourier transform infrared and X-ray diffraction analysis confirmed that the addition of PEG had no effect on the crystal structure of mica.Moreover,no chemical reaction occurred between PEG and mica during the vacuum impregnation process,and no new substance was formed.The maximum load of mica-stabilized PEG was 46.24%,the phase change temperature of M_(400)/PEG was 46.03℃,and the latent heat values of melting and cooling were 77.75 and 77.73 J·g^(−1),respectively.The thermal conductivity of M_(400)/PEG was 2.4 times that of pure PEG.The thermal infrared images indicated that the thermal response of M_(400)/PEG improved relative to that of pure PEG.The leakage test confirmed that mica could stabilize PEG and that M_(400)/PEG had great form-stabilized property.These results demonstrate that M_(400)/PEG has potential in the field of building energy conservation.
基金Funded by the Program of Beijing Municipal Commission of Education
文摘Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol(mPEG-OH), which contained a hydroxyl group combining with hexamethylene diisocyanate(HDI) to form a novel macromonomer namely monomethoxy polyethylene glycol isocyanate(mPEG-NCO) containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted copolymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG- NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The experimental result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling degree in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.
基金This work was supported by a grant from Department of Defense Peer Reviewed Orthopaedic Research Program award(grant No.OR180077 W81XWH-19-2-0054to GDB)。
文摘Complete transection of peripheral mixed nerves immediately produces loss of sensory perception,muscle contractions and voluntary behavior mediated by the severed distal axons.In contrast to natural regeneration(~1 mm/d)of proximal axons that may eventually reinnervate denervated targets,re-innervation is restored within minutes by PEG-fusion that consists of neurorrhaphy and a sequence of well specified hypo-and isotonic calcium-free or calcium-containing solutions,the anti-oxidant methylene blue(MB)and the membrane fusogen polyethylene glycol(PEG).In this study,we examined the relative efficacy of PEG-fusion with no MB(0%),0.5%MB,or 1%MB on the recovery of voluntary behaviors by female Sprague-Dawley rats with a complete mid-thigh severance of their sciatic nerve bathed in extracellular fluid or calcium-containing isotonic saline.The recovery of voluntary behaviors is the most relevant measure of success of any technique to repair peripheral nerve injuries.We assessed recovery by the sciatic functional index,a commonly used measure of voluntary hindlimb behaviors following complete sciatic transections.We reported that both 1%MB and 0.5%MB in sterile distilled water in our PEG-fusion protocol with neurorrhaphy significantly increased the rate and extent of behavioral recovery compared to PEG plus neurorrhaphy alone.Furthermore,0.5%MB was as effective as 1%MB in voluntary behavioral recovery as assessed by the sciatic functional index.Since sterile 1%MB is no longer clinically available,we therefore recommend that 0.5%MB be included in upcoming human clinical trials to evaluate the safety and efficacy of PEG-fusion.All animal procedures were approved by the University of Texas Institutional Animal Care and Use Committee(AUP-2019-00225)on September 9,2020.
基金This work was financially supported by the Natural Science Foundation of China(51974270)Innovation Union of China National Petroleum Corporation and Southwest Petroleum University(2020CX040102,2020CX040201)Open Fund(PLN201814)of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University).
文摘Mud shale hydration and swelling are major challenges in the development of water-based drilling fuids(WBDFs).In this work,the inhibition performance and inhibition mechanism of polyethylene glycol(PEG)and potassium chloride(KCl)were investigated by hot rolling recovery tests,linear swell tests,Fourier transform infrared spectroscopy,X-ray difraction,atomic absorption spectrophotometry and X-ray photoelectron spectroscopy.The experimental results show that the combination of PEG and KCl achieved higher recovery and lower linear swelling rate than those obtained by individual PEG or KCl.Compared to the d-spacing of Na-montmorillonite(Na-Mt)with PEG or KCl,the d-spacing of Na-Mt with PEG+KCl was lower,which indicates that KCl and PEG have synergistic inhibition efect.This synergistic efect can replace sodium ions and water molecules from the interlayer space of Na-Mt and decrease the d-spacing of Na-Mt.Based on the above experimental results and analysis,a method for optimizing PEG and KCl concentrations was proposed and further verifed by rheological and hot rolling recovery tests of WBDFs.Hence,the results of this work can provide valuable theoretical guidance for developing other synergistic inhibitors.
基金the grant from Ministerio de Ciencia e Innovación,No.PID2019-104130RB-I00.
文摘BACKGROUND Acute pancreatitis(AP)is a sudden inflammatory process of the pancreas that may also involve surrounding tissues and/or remote organs.Inflammation and parenchymal cell death are common pathological features of this condition and determinants of disease severity.Polyethylene glycols(PEGs)are nonimmunogenic,non-toxic water-soluble polymers widely used in biological,chemical,clinical and pharmaceutical settings.AIM To evaluate the protective effect of a 35-kDa molecular weight PEG(PEG35)on the pancreatic damage associated to cerulein-induced acute pancreatitis in vivo and in vitro.METHODS Wistar rats were assigned at random to a control group,a cerulein–induced AP group and a PEG35 treatment group.AP was induced by five hourly intraperitoneal injections of cerulein(50μg/kg/bw),while the control animals received saline solution.PEG35 was administered intraperitoneally 10 minutes before each cerulein injection in a dose of 10 mg/kg.After AP induction,samples of pancreatic tissue and blood were collected for analysis.AR42J pancreatic acinar cells were treated with increasing concentrations of PEG35 prior to exposure with tumor necrosis factorα(TNFα),staurosporine or cerulein.The severity of AP was determined on the basis of plasma levels of lipase,lactate dehydrogenase activity,pancreatic edema and histological changes.To evaluate the extent of the inflammatory response,the gene expression of inflammation-associated markers was determined in the pancreas and in AR42J-treated cells.Inflammation-induced cell death was also measured in models of in vivo and in vitro pancreatic damage.RESULTS Administration of PEG35 significantly improved pancreatic damage through reduction on lipase levels and tissue edema in cerulein-induced AP rats.The increased associated inflammatory response caused by cerulein administration was attenuated by a decrease in the gene expression of inflammation-related cytokines and inducible nitric oxide synthase enzyme in the pancreas.In contrast,pancreatic tissue mRNA expression of interleukin 10 was markedly increased.PEG35 treatment also protected against inflammation-induced cell death by attenuating lactate dehydrogenase activity and modulating the pancreatic levels of apoptosis regulator protein BCL-2 in cerulein hyperstimulated rats.Furthermore,the activation of pro-inflammatory markers and inflammationinduced cell death in pancreatic acinar cells treated with TNFα,cerulein or staurosporine was significantly reduced by PEG35 treatment,in a dose-dependent manner.CONCLUSION PEG35 ameliorates pancreatic damage in cerulein-induced AP and AR42J-treated cells through the attenuation of the inflammatory response and associated cell death.PEG35 may be a valuable option in the management of AP.
基金This study was supported by the National Natural Science Foundation of China(No.81871473)and the Natural Science Foundation of Zhejiang Chinese Medical University(No.2018ZZ11).
文摘D-a-tocopherol polyethylene glycol 1000 succinate(TPGS)is a pharmaceutical excipient approved by Chinese NMPA and FDA of USA.It's widely applied as a multifunctional drug carrier for nanomedicine.The advantages of TPGS include P-glycoprotein(P-gp)inhibition,penetration promotion,apoptosis induction via mitochondrial-associated apoptotic pathways,multidrug resistant(MDR)reversion,metastasis inhibition and so on.TPGS-based drug delivery systems which are responding to extermal stimulus can combine the inhibitory functions of TPGS towards P-gp with the environmentally responsive controlled release property and thus exerts a synergistic anti-cancer effect,through increased intracellular drug concentration in tumors cells and well-controlled drug release behavior.In this review,TPGS-based nano-sized delivery systems responsive to different stimuli were summarized and discussed,including pH-responsive,redox-responsive and multi-responsive systems in various formulations.The achievements,mechanisms and diffcrent characteristics of TPGS-bascd stimuli-responsive drug-delivery systems in tumor therapy were also outlined.
基金sponsored by grants from the National Natural Science Foundation of China,No.30872603the New Century Excellent Talents Program of the Ministry of Education of China,No.NCET-06-0251the Applied Basic Research Programs of Science and Technology Commission Foundation of Tianjin,China,No.07JCYBJC10200
文摘Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fiuorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.
文摘Polyethylene glycol(PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays(MEA) were used to measure mean firing rate(MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups(P 〈 0.01, P 〈 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.
文摘The catalyst boron trifluoride etherate was used to catalyze the reaction of epoxy resin with polyethylene glycol (PEG), and the effect of the concentration of the catalyst on the reaction is studied. It is shown that there exist two competitive reactions : I, self polymerization of epoxy resin via chain growth and II, copolymerization of epoxy resin with PEG via step growth. At high concentration of the catalyst reaction I dominates and reaction II is negligible. On the contrary, at low concentration of the catalyst, reaction II dominates and block copolymers are formed In the intermediate case, the two reactions are comparable with the result that a gel structure is obtained.
基金supported by the National Natural Science Foundation of China(No.21172125)the Ministry of Science and Technology (2012BAD32B10)+1 种基金the "111" Project of Ministry of Education of China(Project No.B06005)the Committee of Science and Technology of Tianjin
文摘The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG 1000 under 5 MPa of CO2 and 2 MPa of O2 at 100 ℃ for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.