Polydopamine-modified chitin conduits with sustained release of bioactive peptides enhance peripheral nerve regeneration in rats

The introduction of neurotrophic factors into injured peripheral nerve sites is beneficial to peripheral nerve regeneration.However,neurotrophic facto rs are rapidly degraded in vivo and obstruct axonal regeneration when used at a supraphysiological dose,which limits their clinical benefits.Bioactive mimetic peptides have been developed to be used in place of neurotrophic factors because they have a similar mode of action to the original growth fa ctors and can activate the equivalent receptors but have simplified sequences and structures.In this study,we created polydopamine-modified chitin conduits loaded with brain-derived neurotrophic factor mimetic peptides and vascular endothelial growth fa ctor mimetic peptides(Chi/PDA-Ps).We found that the Chi/PDA-Ps conduits were less cytotoxic in vitro than chitin conduits alone and provided sustained release of functional peptides.In this study,we evaluated the biocompatibility of the Chi/P DA-Ps conduits.Brain-derived neurotrophic factor mimetic peptide and vascular endothelial growth fa ctor mimetic peptide synergistically promoted prolife ration of Schwann cells and secretion of neurotrophic factors by Schwann cells and attachment and migration of endothelial cells in vitro.The Chi/P DA-Ps conduits were used to bridge a 2 mm gap between the nerve stumps in rat models of sciatic nerve injury.We found that the application of Chi/PDA-Ps conduits could improve the motor function of rats and reduce gastrocnemius atrophy.The electrophysiological results and the microstructure of regenerative nerves showed that the nerve conduction function and re myelination was further resto red.These findings suggest that the Chi/PDA-Ps conduits have great potential in peripheral nerve injury repair.

New indicators in evaluation of hemolysis,elevated liver enzymes,and low platelet syndrome:A case-control study

BACKGROUND Indices such as the neutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyte ratio(PLR),mean platelet volume(MPV),platelet distribution width(PDW),and red cell distribution width(RDW)are considered new markers of the systemic inflammatory response(SIR),and have been widely implemented for the diagnosis of patients with inflammatory diseases.These new indicators have also been widely investigated in preeclampsia(PE)but less analyzed in hemolysis,elevated liver enzymes,and low platelet(HELLP)syndrome.AIM To compare SIR markers among HELLP patients,PE only patients,and healthy gravidae.METHODS This retrospective case-control study enrolled 630 cases,including 210 patients with HELLP syndrome(HELLP group),210 patients with only PE(PE group)and 210 healthy gravidae(control group).The three groups were matched by age,parity,status of assisted reproduction,and multiple pregnancies.Birthweight,gestational age at complete blood count collection,gestational age at delivery,mode of delivery,etc.were recorded.The main indices as NLR,PLR,MPV,PDW,and RDW among the groups were compared,as well as some secondary outcomes including neutrophil,platelets,and hemoglobin.RESULTS The NLR(6.4 vs 4.3 vs 3.5),MPV(11.9 vs 11.2 vs 10.7),PDW(16.4 vs 13.3 vs 14.2),leukocyte(12.4×10^(9)/L vs 9.7×10^(9)/L vs 8.7×10^(9)/L)and neutrophil count(9.9×10^(9)/L vs 7.3×10^(9)/L vs 6.1×10^(9)/L)were highest in the HELLP group,lower in the PE group,and lowest in the control group.Both the overall comparisons between the three groups(all bP<0.01)and pairwise comparisons between every two groups elicited statistically significant differences(all dP<0.01,except control vs PE:cP<0.05 in PDW).The average lymphocyte counts were 1.4(1.1,2.0)×10^(9)/L in the HELLP group,1.6(1.3,2.0)×10^(9)/L in the PE group and 1.7(1.4,2.0)×10^(9)/L in the control group.The overall comparison of lymphocyte count within the three groups had statistically significant differences(P=0.000).The pairwise comparisons between every two groups demonstrated that the HELLP group had a lower lymphocyte count than both the PE(P=0.019)and control groups(P=0.000),but the difference between the PE and control groups was not statistically significant(P=0.432).The overall comparisons on platelet counts and the PLR among these three groups also showed statistically significant differences(both P=0.000),from low to high being those in the HELLP group(43.4×10^(9)/L,64.0),control group(180.5×10^(9)/L,103.6)and PE group(181.5×10^(9)/L,112.8).Pairwise comparisons of neither index displayed statistically significant differences between the PE and control groups(both P>0.05),while the differences in the two indices between the HELLP group and the two other groups were still statistically significant(all P=0.000).RDW values were highest in the HELLP group(14.5%[13.6,15.3]),lower in the control group(14.1%[13.5,14.8])and lowest in the PE group(13.9%[13.4,14.9]).The difference between the PE and control group did not show statistical significance(P=1.000),while RDW values in the HELLP group were higher than those in the other two groups(cP<0.05 vs control,dP<0.01 vs PE).CONCLUSION SIR markers such as NLR,RDW,MPV,and PDW were increased and PLR was decreased in HELLP.These SIR markers may become new indicators in the evaluation of HELLP syndrome.

Melittin analog p5RHH enhances recombinant adeno-associated virus transduction efficiency

Objective Melittin and its derivatives have been characterized to establish effective gene delivery systems.Their capability of facilitating endosomal release enhances the nanoparticles-based gene delivery.Nevertheless,little investigation has been conducted to explore its potential application in the context of viral vectors.Methods Various melittin-derived peptides were inserted into the loop VIII of the capsid proteins of recombinant adeno-associated virus vectors.These vectors carrying either gfp or fluc genes were subjected to qPCR assays and transduction assays of HEK293T cells to investigate the efficiency of vector production and gene delivery.In addition,the ability of a specific p5RHH-rAAV vector to deliver genes was examined through in vitro transduction of different cultured cells and in vivo tail vein administration to C57BL/6 mice.Finally,the intricate details of the vector-mediated transduction mechanisms were revealed by specific pharmacological inhibitors of every stage of the rAAV2 intracellular life cycle.Results A total of 76 melittin-related peptides were compiled from existing literature.Among them,cMA2,Melt13,p5RHH and aAR3 were found to significantly enhance the gene delivery efficiency of rAAV2 vectors.The p5RHH-rAAV2 vectors efficiently transduced not only rAAV-potent cell lines but also cell lines previously considered resistant to rAAV.Mechanistically,bafilomycin A1,a vacuolar endosome acidification inhibitor,completely inhibited the transgene expression mediated by the p5RHH-rAAV2 vectors.Most importantly,p5RHH-rAAV8 vectors also demonstrated increased hepatic transduction in vivo in C57BL/6 mice.Conclusion The incorporation of melittin analogues into the rAAV capsids results in a significant improvement in rAAV-mediated transgene expression.While further modifications remain an area of interest,our studies have substantially broadened the pharmacological prospects of melittin in the context of viral vector-mediated gene delivery.

A new staging system for hepatocellular carcinoma associated with portal vein tumor thrombus

Background:A new staging system for patients with hepatocellular carcinoma(HCC)associated with portal vein tumor thrombus(PVTT)was developed by incorporating the good points of the BCLC classification of HCC,and by improving on the currently existing classifications of HCC associated with PVTT.Methods:Univariate and multivariate analysis with Waldχ2 test were used to determinate the clinical prognostic factors for overall survival(OS)in patients with HCC and PVTT in the training cohort.Then the conditional inference trees analysis was applied to establish a new staging system.Results:A training cohort of 2,179 patients from the Eastern Hepatobiliary Surgery Hospital and a validation cohort of 1,550 patients from four major liver centers in China were enrolled into establishing and validating a new staging system.The system was established by incorporating liver function,general health status,tumor resectability,extrahepatic metastasis and extent of PVTT.This staging system had a good discriminatory ability to separate patients into different stages and substages.The median OS for the two cohorts were 57.1(37.2-76.9),12.1(11.0-13.2),5.7(5.1-6.2),4.0(3.3-4.6)and 2.5(1.7-3.3)months for the stages 0 to IV,respectively(P<0.001)in the training cohort.The corresponding figures for the validation cohort were 6.4(4.9-7.9),2.8(1.3-4.4),10.8(9.3-12.4),and 1.5(1.3-1.7)months for the stages II to IV,respectively(P<0.001).The mean survival for stage 0 to 1 were 37.6(35.9-39.2)and 30.4(27.4-33.4),respectively(P<0.001).Conclusions:A new staging system was established which provided a good discriminatory ability to separate patients into different stages and substages after treatment.It can be used to supplement the other HCC staging systems.

Clinical diagnosis and treatment of intraorbital wooden foreign bodies

Purpose： The intraorbital wooden foreign body is often misdiagnosed or missed on computed tomog- raphy （CT） scan, due to the invisible or unclear images. The residual foreign bodies often occur during surgical removal. The clinical manifestations, imaging features and treatment of intraorbital wooden foreign bodies were discussed in this study. Method： We retrospectively analyzed 14 cases of intraorbital wooden foreign bodies managed at our hospital between January 2007 and May 2015. All patients underwent orbital CT examination before surgery, and surgery was performed under general anesthesia with orbital wound debridement and suture, as well as exploration and removal of wooden foreign bodies. Results： At first, 11 cases underwent removal of foreign bodies, including 1 case with incomplete removal and then receiving a secondary surgery. Foreign bodies were not found in three cases with preoperative misdiagnosis and orbital MRI found residual foreign bodies in the orbit. Operations were performed via primary wound approach in eight cases, conjunctival approach in two cases, and anterior orbitotomy in four cases. Postoperatively, one case was complicated with eye injuries, three cases with ocular muscle injuries, eight cases with visual loss, and eight cases with orbital abscess. The length of foreign bodies ranged from 1.8 cm to 11.0 cm. The maximum of four foreign bodies were removed at the same time. Conclusion： Because the imaging of orbital wooden foreign bodies is complex and varied, MRI should be combined when they are invisible on CT scan. At the same time injuries trajectory and clinical manifestations of patients should be taken into account. Surgical exploration should be extensive and thorough, and foreign bodies and orbital abscess must be cleared.