Polyethylene glycol fusion repair of severed rat sciatic nerves reestablishes axonal continuity and reorganizes sensory terminal fields in the spinal cord

Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.

Polyethylene glycol has immunoprotective effects on sciatic allografts, but behavioral recovery and graft tolerance require neurorrhaphy and axonal fusion

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.

Polyethylene glycol fusion repair of severed sciatic nerves accelerates recovery of nociceptive sensory perceptions in male and female rats of different strains

Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.

Reaction pathways and selectivity in the chemo-catalytic conversion of cellulose and its derivatives to ethylene glycol:A review

Biomass-to-ethylene glycol is an effective means to achieve high-value utilisation of cellulose but is hindered by low conversion efficiency and poor catalyst activity and stability.Glucose and cellobiose are derivatives of cellulose conversion to ethylene glycol,and it is found that studying the reaction process of both can help to understand the reaction mechanism of cellulose.It is desirable to develop a reusable,highly active catalyst to convert cellulose into ethylene glycol.This ideal catalyst might have one or more active sites described the conversion steps above.Here,we discuss the catalyst development of celluloseto-ethylene glycol,including tungsten,tin,lanthanide,and other transition metal catalysts,and special attention is given to the reaction mechanism and kinetics for preparing ethylene glycol from cellulose,and the economic advantages of biomass-to-ethylene glycol are briefly introduced.The insights given in this review will facilitate further development of efficient catalysts,for addressing the global energy crisis and climate change related to the use of fossil fuels.

Sn nucleation and growth from Sn(II)dissolved in ethylene glycol:Electrochemical behavior and temperature effect

Thermodynamic and kinetic aspects of Sn nucleation and growth processes onto a glassy carbon electrode from SnCl2·2H2O dissolved in ethylene glycol solutions were studied.Typical reduction and oxidation peaks observed in voltammograms have demonstrated the capability of ethylene glycol solutions to electrodeposit Sn.The temperature-dependence of diffusion coefficient values derived from potentiodynamic and potentiostatic studies helped to determine and validate estimations of the activation energy for Sn(II)bulk diffusion.Chronoamperometric results have identified that,the suitable model to describe the early stage of Sn electrodeposition could be composed of Sn three-dimensional nucleation and diffusion-controlled growth and water reduction contributions,which was duly validated by theoretical and experimental approaches.From the model,typical kinetic parameters such as the nucleation frequency of Sn(A),number density of Sn nuclei(N_(0)),and diffusion coefficient of Sn(II)ions(D),were determined.The presence of Sn nuclei with excellent quality and their structures were verified using SEM,EDX,and XRD techniques.

Chiral fluorescent sensor Tb^(3+)@Cd‑CP based on camphoric acid for the enantioselective recognition of R‑and S‑propylene glycol

Herein,a layered chiral coordination polymer,[Cd2(D‑cam)_(2)(2,2′‑bipy)_(2)]_(n)(Cd‑CP),was synthesized using a solvothermal method with camphoric acid(D‑H_(2)cam),2,2′‑bipyridine(2,2′‑bipy)and Cd^(2+),and Tb^(3+)@Cd‑CP was in‑situ synthesized introducing Tb^(3+)ions.The fluorescence experiments revealed that compared to Cd‑CP,Tb^(3+)@Cd‑CP exhibited ultra‑high fluorescence performance.The luminescence sensing performance demonstrated that Tb^(3+)@Cd‑CP could distinguish R/S‑propylene glycol(R/S‑PG)by fluorescence responses,with fluorescence quenching constant of 5.3×10^(3)and 2.0×10^(3)L·mol^(-1)respectively and the enantioselectivity factor(α)of 2.65.Moreover,Tb^(3+)@Cd‑CP demonstrated limits of detection of 9.3 and 19.0μmol·L^(-1)for R‑PG and S‑PG,respectively,and showed good reproducibility.

Influence of glycol ether additive with low molecular weight on the interactions between CO_(2) and oil: Applications for enhanced shale oil recovery

The high-efficient development of shale oil is one of the urgent problems in the petroleum industry. The technology of CO_(2) enhanced oil recovery(EOR) has shown significant effects in developing shale oil. The effects of several glycol ether additives with low molecular weight on the interactions between CO_(2) and oil were investigated here. The solubility of glycol ether additive in CO_(2) was firstly characterized. Then,the effects of glycol ether additives on the interfacial tension(IFT) between CO_(2) and hexadecane and the volume expansion and extraction performance between CO_(2) and hexadecane under different pressures was investigated. The experimental results show that diethylene glycol dimethyl ether(DEG), triethylene glycol dimethyl ether(TEG), and tetraethylene glycol dimethyl ether(TTEG) all have low cloud point pressure and high affinity with CO_(2). Under the same mass fraction, DGE has the best effect to reduce the IFT between hexadecane and CO_(2) by more than 30.0%, while an overall reduction of 20.0%-30.0% for TEG and 10.0%-20.0% for TTEG. A new method to measure the extraction and expansion rates has been established and can calculate the swelling factor accurately. After adding 1.0% DEG, the expansion and extraction amounts of CO_(2) for hexadecane are respectively increased to 1.75 times and 2.25 times. The results show that glycol ether additives assisted CO_(2) have potential application for EOR. This study can provide theoretical guidance for the optimization of CO_(2) composite systems for oil displacement.

Vertically aligned montmorillonite aerogel-encapsulated polyethylene glycol with directional heat transfer paths for efficient solar thermal energy harvesting and storage

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.

稀土钐-聚乙二醇高分子转光剂的合成及其荧光性能

以三聚氯氰交联月桂醇、8-羟基喹啉和聚乙二醇制备高分子配体CHA(PEG),再与稀土Sm 3+中心离子配位合成了一种新型高分子转光剂Sm[CHA(PEG)].采用FTIR、XPS、XRD、荧光光谱、UV和TGA等测试方法分析了Sm[CHA(PEG)]的化学结构、荧光性能以及热稳定性等.结果表明,Sm[CHA(PEG)]在320~400 nm具有紫外宽吸收带,而荧光激发峰的最佳峰位在362 nm处,二者具有良好的吻合性;荧光发射峰在566 nm、614 nm和645 nm均出现了Sm 3+的特征发射峰,其中在645 nm处强度最大,与植物在红光区光合作用的吸收光谱具有较佳的匹配性.热失重曲线显示该转光剂的分解温度为281℃,热稳定性良好.本文合成的Sm[CHA(PEG)]具有优良的光学和热学性能,在农膜领域极具应用前景.

比较不同免疫分型丙型肝炎的治疗效果

目的:本研究旨在分析不同免疫分型丙型肝炎患者在接受相同治疗方案后的的临床治疗效果以及病毒应答率差异。方法:选取西安市中心医院诊断为慢性丙型肝炎的患者100例,所有患者采用聚乙二醇干扰素联合利巴韦林治疗48周,采用丙型肝炎基因分型检测试剂盒对患者的感染亚型进行精确分型。在治疗的关键节点(如4周、12周、24周)留存患者血清,检测患者HCV RNA病毒载量以及生化肝功能指标AST、ALT。在所有患者治疗结束后24周,再次抽取患者血清,检测HCV RNA病毒载量,计算病毒应答率。结果:本研究入组患者主要基因亚型为1b型与3b型。对于1b型患者,该治疗方案对降低HCV RNA病毒载量效果较差,且在降低患者血清中AST、ALT含量效果一般。对3a、3b、6a亚型患者,该治疗方案在降低病毒载量以及血清中AST、ALT含量表现出较好的效果。整体病毒应答率上,1b型和其他各型相比表现不敏感(P<0.05),差异具有统计学意义。结论:鉴于地区间丙型肝炎感染亚型的差异以及患者的经济状况和身体耐受性差异,建议在初治患者反应不佳时,进行基因型分型,以便及时调整方案,为患者提供更有效的治疗。

Electrodeposition behavior of bright nickel in air and water-stable betaine·HCl-ethylene glycol ionic liquid

The electrodeposition behaviors of nickel on glassy carbon（GC） and carbon steel（CS） electrodes were investigated in the14.3%-85.7%（mole fraction） betaine.HCl ethylene glycol（EG） ionic liquid using cyclic voltammetry and chronoamperometry.The results indicated that the reduction of Ni（Ⅱ） on CS electrode via a diffusion-controlled quasi-reversible process was much more facile and easier than that occurred on GC electrode,which followed a diffusion-controlled three-dimensional instantaneous nucleation and growth.Scanning electron microscopy was used to observe that the deposit was dense and contained fine crystallites with average size of（80±4） nm.Energy dispersive spectrometer analysis showed that the obtained deposit was metallic nickel.X-ray diffraction spectroscopy indicated that（111） plane was the most preferred crystal orientation.The nickel deposit was luminous and bright,and had good adhesion with the CS substrate.

Effects of Oral Administration of Propylene Glycol and Ca-P-Mg Mixture on Milk Quality and SCC of Dairy Cows after Birth

In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cows after birth were investigated. The results showed that the milk fat and dry matter contents in the dairy cows administered with Ca-P-Mg mixture and compound oral rehydration salts were higher than those in the dairy cows administered with propylene glycol（P 〈0.05）. However, there were no significant differences in milk sugar and protein contents and SCC between the two administration groups.

生物基乙醇酸及聚乙醇酸的合成研究

该研究利用自制生物质糖进行发酵,通过系统的分离纯化研究,建立低成本生物基乙醇酸和聚乙醇酸的生产工艺。利用低共熔溶剂处理,玉米芯水解葡萄糖液质量浓度达到148.05 g/L,转化率达到93.10%;5 L罐乙醇酸产量达49.80 g/L,相比利用葡萄糖提高16.00%;通过对钙化、酸化、结晶等分离纯化工艺开展研究,乙醇酸回收率达到87.50%,乙醇酸晶体纯度达到99.50%,符合市售优级品标准;利用共沸蒸馏法进行聚合,红外和核磁证实了聚乙醇酸的产生且其结晶度高达89.60%。上述结果表明,生物基乙醇酸生产体系的初步建立,为乙醇酸及其聚合物的工业化生产奠定了基础。

在真实世界中使用2 L和3 L聚乙二醇电解质溶液进行肠道准备的效果比较

目的比较在真实世界中2 L及3 L聚乙二醇电解质溶液(polyethylene glycol,PEG)的肠道准备效果。方法本研究为真实世界环境中单中心的队列研究,研究对象为2023年5-10月在成都市第三人民医院消化内科接受结肠镜检查并使用2 L或3 L PEG进行肠道准备的患者。根据纳排标准,3 L组共纳入3700例,2 L组共纳入4684例。主要结果指标是根据波士顿肠道准备评分(Boston bowel preparation score,BBPS)计算的肠道准备充分率;次要结果包括BBPS分数、息肉检出率(polyp detection rate,PDR)、耐受性、依从性和不良反应。结果3 L组的肠道准备充分率为94.35%,高于2 L组的91.29%(P<0.001);BBPS总分为(6.92±1.06)分,高于2 L组的(6.81±1.14)分(P<0.001)。2组的PDR无统计学差异(P=0.073)。2组患者PEG完成率(P=0.810)、按要求进行低渣饮食(P=0.094)及服用二甲硅油(P=0.072)差异均无统计学意义。3 L组的呕吐率(4.5%vs 3.2%,P=0.002)、腹部不适率(5.0%vs 3.9%,P=0.011)和睡眠障碍率(18.0%vs 14.6%,P<0.001)高于2 L组。结论在真实世界,2 L PEG是一种安全有效的肠道准备方案。

5R,6S-Tg立体异构体稳定构型的理论研究

胸腺嘧啶二醇(Thymine glycol,Tg)是最常见的DNA氧化损伤,人体基因组内含有数千个Tg损伤.Tg对DNA聚合酶有强的阻断,可能导致细胞死亡、癌症等严重后果.一旦生成,Tg就以两对顺反立体异构体混合物的形式存在,修复酶对Tg的修复表现出立体选择性.在所有的异构体中,5R,6S-Tg数量最多.NMR实验表明5R,6S-Tg 5-CH_(3)可能存在轴向或赤道两种不同构象,但是5R,6S-Tg最稳定构象依然存在争论.基于碱基水平的理论研究表明5R,6S-Tg 5-CH_(3)取向为轴向时最稳定.然而,本研究在核苷水平的计算表明,5-CH_(3)取向为赤道时最稳定,高精度的簇耦合理论CCSD(T)/6-311++G(d,p)对结果进行了验证.进一步的分析表明,分子内氢键和氧孤电子对之间的π-π共轭协同作用稳定了5R,6S-Tg的赤道构象.

三种乙二醇醚对乙二醇-水溶液性能及铜缓蚀效果影响研究

通过凝点、黏度、导热系数及导电系数测定,考察乙烯基乙二醇、聚乙二醇单丁醚、聚乙二醇添加比例对乙二醇水溶液性能的影响;采用静态失重法和表面分析方法研究了三种乙二醇醚缓蚀性能。结果表明:三种乙二醇醚的加入降低了乙二醇水基液的凝点和导热系数,增大了基液的黏度和导电系数。经过14 d铜片腐蚀测定结果和SEM形貌分析表面,证明三种乙二醇醚能有效抑制乙二醇水溶液对铜的腐蚀。失重法测定了缓蚀效率,结果表明,乙烯基乙二醇添加量为20%(质量分数,下同)时缓蚀效率可达到82.14%;聚乙二醇(200)添加量为5%时,缓蚀效率为60.71%;聚乙二醇单丁醚(200)含量为20%时,缓蚀效率为28.57%。实验结果证明了三种乙二醇醚均对乙二醇水溶液产生了缓蚀效果,聚乙二醇及乙烯基乙二醇对乙二醇水溶缓蚀作用效果良好。

羧甲基纤维素/竹粉吸水树脂的制备及其性能研究

以羧甲基纤维素(CMC)、竹粉(BP)为主要原料,以聚乙二醇二缩水甘油醚(PEGDE)为交联剂,制备了可降解CMC/BP吸水树脂。探究了BP用量、交联剂用量和反应温度对CMC/BP吸水树脂性能的影响,通过X射线衍射仪、傅里叶变换红外光谱仪、扫描电子显微镜对CMC/BP吸水树脂的微观形貌、结构进行表征并测试了其吸水性能和保水性能。结果表明当CMC用量为4g, BP用量为5g, PEGDE用量为13mL,反应温度为60℃时,制备的CMC/BP吸水树脂吸水率达到21.1g/g,吸水120h后保水率达到55%,吸水和保水性能最好。

Atmospheric reductive catalytic fractionation of lignocellulose integrated with one-pot catalytic conversion of carbohydrate yielding valuable lignin monomers and platform chemicals from corn straw

Developing a cost-effective and environmentally friendly process for the production of valuable chemicals from abundant herbal biomass receives great attentions in recent years.Herein,taking advantage of the“lignin first”strategy,corn straw is converted to valuable chemicals including lignin monomers,furfural and 5-methoxymethylfurfural via a two steps process.The key of this research lies in the development of a green and low-cost catalytic process utilizing magnetic Raney Ni catalyst and high boiling point ethylene glycol.The utilization of neat ethylene glycol as the sole slovent under atmospheric conditions obviates the need for additional additives,thereby facilitating the entire process to be conducted in glass flasks and rendering it highly convenient for scaling up.In the initial step,depolymerization of corn straw lignin resulted in a monomer yield of 18.1 wt%.Subsequently,in a dimethyl carbonate system,the carbohydrate component underwent complete conversion in a one-pot process,yielding furfural and 5-methoxymethylfurfural as the primary products with an impressive yield of 47.7%.

桃红侧耳原生质体细胞融合选育高产菌丝蛋白菌株

随着人口的快速增长,全球范围内对优质蛋白质的需求日益增强,通过食用菌育种技术培育高产、高蛋白的优质菌株,将菌丝体蛋白用作新的蛋白质来源,可以缓解蛋白质短缺的问题。该研究以桃红侧耳GXGD-13-1为原始菌株,通过原生质体细胞融合技术,提高桃红侧耳菌丝体的蛋白质产量。菌丝体的细胞壁在组合酶M2中酶解3 h,释放的原生质体利用250 g/L的聚乙二醇为融合剂进行聚集融合,最终融合率达到53%,有效克服了桃红侧耳四极性的交配系统亲和率低的育种壁垒。融合再生后的菌株经过选育高产菌丝蛋白菌株的初筛和复筛,得到融合菌株R-1,经凯氏定氮仪测定,计算其菌丝体蛋白质产量比原始菌株GXGD-13-1提高约23%。该文的实验工作,证明了原生质体细胞融合育种技术对选育高产菌丝体蛋白质菌株的有效性,为满足不断增长的蛋白质需求提供新的有效途径。

A Self-assembled Nanomicelle for Realizing Tumor Photodynamic Therapy via Increasing Drug Accumulation and Prolonging Retention Time

A nanomicelle(denoted as TPGS/Ppa)was fabricated via the coassembly of the amphiphilic D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)and the hydrophobic photosensitizer pyropheophorbide a(Ppa)for photodynamic therapy(PDT).The obtained nanomicelle possessed a spherical structure with a diameter of(18.0±2.2)nm and a zeta potential of approximately -18 mV.Besides,the nanomicelle exhibited excellent photostability,biocompatibility,and phototoxicity,and could effectively reach the tumor region via the enhanced permeability and retention effect.Additionally,it could be found that the TPGS/Ppa nanomicelle exhibited higher phototoxicity against 4T1 murine mammary cancer cells than free Ppa.In the 4T1 tumor-bearing mouse model,the nanomicelle showed an excellent antitumor therapeutic effect.This study develops a new type of photodynamic nanomicelle TPGS/Ppa,which can increase the accumulation of drugs and prolong their tumor retention time,providing a feasible strategy for realizing the delivery of small-molecule hydrophobic drugs and tumor PDT.