Objective To achieve serum-free and low-DMSO efficient cell cryopreservation based on self-assembled peptides(Peptide).Methods Hepa1-6 cells were cryopreserved by combining three cryoprotectants(CPAs),FBS,DMSO and Peptide. Confocal microscopy,flow cytometry and cell counting were used to measure the survival rate,recovery rate and proliferation ability of the cells after freezing,and the ice inhibition of CPAs was tested by differential scanning calorimetry(DSC). Finally,a CPA with high efficiency for cell cryopreservation was determined.Results Peptide formed a fibrous network hydrogel in DMSO solution to encapsulate cells and supported them in a three-dimensional(3D)stereological distribution. Under serum-free conditions,the use of 0. 1 wt% Peptide combined with 5% DMSO as a novel composite CPA for cryopreservation of Hepa1-6 cells significantly improved the survival rate and post-freezing recovery rate compared with the5% DMSO and 0. 1 wt% Peptide groups,and there was no significant difference with the 10% DMSO + 20% FBS group(t =0. 983 and 2. 164,respectively,each P > 0. 05). In addition,compared with the 10% DMSO + 20% FBS group,0. 1 wt%Peptide + 5% DMSO group showed no significant difference in cell proliferation ability after freezing-thawing(t = 3. 513,P > 0. 05). In the end,DSC tests showed that Peptide-based CPA had good ice inhibition performance.Conclusion The use of 0. 1 wt% Peptide combined with 5% DMSO as a novel composite CPA has a good effect on cell cryopreservation.

Objective To investigate the clinical significance of soluble intercellular adhesion molecule-1 (sICAM-1) and interleukin-1β(IL-1β) in pregnant women with chorioamnionitis. Methods The levels of sICAM-1, IL-1β,CRP and WBC were detected by enzyme linked immunosorbent assay in maternal serum of 56 pregnant women with PPROM and 38 pregnant women with PROM. Every embryolemma was histopathologically confirmed after deliver-y. Results Chorioamnionitis in PPROM was more than that in PROM of full term(P<0.05). The serum levels of sI-CAM-1, IL-1β, CRP and WBC in chorioamnionitis in pregnant women were higher than those in non-chorioamnionitis (P <0.05). The serum levels of sICAM-1 was more sensitive and specific than those of CRP and WBC. The serum levels of IL-1β was more sensitive than those of CRP and WBC, but their specificity was similar. Conclusion The levels of sICAM-1 and IL-1β in maternal serum are good clinical biological markers for predicting chorioamnionitis in pregnant women.

Objective To evaluate the prognostic value of transcutaneous oximetry in patients with septic shock.Methods Fifty-three patients with septic shock were enrolled prospectively from January 2013 to December 2015.Transcutaneous oximetry were used to determine the results of 10 min oxygen challenge tests (OCT) carried out at beginning(0 h) and at 6 h after fluid resuscitation respectively.The 10-min OCT value (10 min OCT) and oxygen challenge index(OCI) were calculated.The APACHE Ⅱ and SOFA score,hemodynamic variables,oxygen metabolism indexes,dose of vasoactive agents,10 min OCT,and OCI at 0 h and at 6 h were recorded.Patients were assigned into survival group and death group according to the 28 d survival.The differences in demographics and clinical data were compared between groups.The role of 10 min OCT and OCI in predicting death was evaluated by receiver operating characteristic curves(ROC).The Kaplan-Meier surviving curve was created and the survival of the patients was analyzed by the Log-rank test.Risk factors associated with the prognosis were analyzed using the multiple logistic regression analysis.Results There were 29 patients in the survival group and 24 patients in the death group.Compared with death group,10 min OCT[(77.55±18.48)mmHg vs.(51.30±21.60)mmHg] and OCI [(0.78±0.13) vs.(0.59±0.15)] at 6 h in survival group were significantly higher(P＜0.05),while APACHE Ⅱ [(12.48±5.69) vs.(17.25±8.79)] and SOFA [(5.79±1.72) vs.(10.10±2.52)] in survival group were significantly lower than those in death group(P＜0.01).The area under the ROC curve of 10 min OCT at 6 h and OCI at 6 h for predicting 28 d death were 0.86±0.05(95％CI:0.76-0.87,P＜0.01) and 0.79±0.08(95％CI:0.64-0.95,P＜0.01),respectively.The optimal cutoff point for 10 min OCT at 6 h was 72.00 mmHg with the sensitivity of 76.84％ and specificity of 85.03％.The optimal cutoff point for OCI at 6 h was 0.76 with the sensitivity of 76.84％ and specificity of 77.47％.Kaplan-Meier survival analysis showed that 28 d survival rate in high level of 10 min OCT at 6 h and high level of OCI at 6 h were significantly higher than that in low level of 10 min OCT at 6 h(70.86％ vs.31.82％,x2=7.96,P＜0.01)and low level of OCI at 6 h (75.00％ vs.32.00％,x2=9.86,P＜0.01).Multivariate logistic regression analysis showed that both 10 min OCT at 6 h (OR=0.92,95％CI:0.88-0.96,P＜0.05) and OCI at 6 h (OR=0.01,95％CI:0.001-0.023,P＜0.05) were independent risk factors associated with 28 d mortality of patients with septic shock.Conclusions The 10 min OCT and OCI were reliable predictors for the prognosis of patients with septic shock.

BACKGROUND:Due to the sudden release and the rapid removal by proteases,platelet-rich plasma hydrogel leads to shorter residence times of growth factors at the wound site.In recent years,researchers have focused on the use of hydrogels to encapsulate platelet-rich plasma in order to improve the deficiency of platelet-rich plasma hydrogels. OBJECTIVE:To prepare self-assembled polypeptide-platelet-rich plasma hydrogel and to explore its effects on the release of bioactive factors of platelet-rich plasma. METHODS:The self-assembled polypeptide was synthesized by the solid-phase synthesis method,and the solution was prepared by D-PBS.Hydrogels were prepared by mixing different volumes of polypeptide solutions with platelet-rich plasma and calcium chloride/thrombin solutions,so that the final mass fraction of polypeptides in the system was 0.1%,0.3%,and 0.5%,respectively.The hydrogel state was observed,and the release of growth factors in platelet-rich plasma was detected in vitro.The polypeptide self-assembly was stimulated by mixing 1%polypeptide solution with 1%human serum albumin solution,so that the final mass fraction of the polypeptide was 0.1%,0.3%,and 0.5%,respectively.The flow state of the liquid was observed,and the rheological mechanical properties of the self-assembled polypeptide were tested.The microstructure of polypeptide(mass fraction of 0.1%and 0.001%)-human serum albumin solution was observed by scanning electron microscope and transmission electron microscope. RESULTS AND CONCLUSION:(1)Hydrogels could be formed between different volumes of polypeptide solution and platelet-rich plasma.Compared with platelet-rich plasma hydrogels,0.1%and 0.3%polypeptide-platelet-rich plasma hydrogels could alleviate the sudden release of epidermal growth factor and vascular endothelial growth factor,and extend the release time to 48 hours.(2)After the addition of human serum albumin,the 0.1%polypeptide group still exhibited a flowing liquid,the 0.3%polypeptide group was semi-liquid,and the 0.5%polypeptide group stimulated self-assembly to form hydrogel.It was determined that human serum albumin in platelet-rich plasma could stimulate the self-assembly of polypeptides.With the increase of the mass fraction of the polypeptide,the higher the storage modulus of the self-assembled polypeptide,the easier it was to form glue.(3)Transmission electron microscopy exhibited that the polypeptide nanofibers were short and disordered before the addition of human serum albumin.After the addition of human serum albumin,the polypeptide nanofibers became significantly longer and cross-linked into bundles,forming a dense fiber network structure.Under a scanning electron microscope,the polypeptides displayed a disordered lamellar structure before adding human serum albumin.After the addition of human serum albumin,the polypeptides self-assembled into cross-linked and densely arranged porous structures.(4)In conclusion,the novel polypeptide can self-assemble triggered by platelet-rich plasma and the self-assembly effect can be accurately adjusted according to the ratio of human serum albumin to polypeptide.This polypeptide has a sustained release effect on the growth factors of platelet-rich plasma,which can be used as a new biomaterial for tissue repair.