可注射、组织黏附性PVA/淀粉水凝胶对力学失稳条件下关节软骨退变抑制作用的研究

Investigation of the inhibitory effect of injectable and tissue-adhesive polyvinyl alcohol/starch hydrogels on articular cartilage degeneration in a joint mechanical instability model

目的制备一种仿生正常关节滑液流变学特征的组织黏附性可注射水凝胶,并研究该水凝胶抑制膝关节创伤后软骨退变的效果及其可能的机制。方法以聚乙烯醇溶液(PVA)、淀粉和氯化钠为主要原料制备可注射、组织黏附性水凝胶(PWN)。通过流变学测试、注射器推出实验、体外降解实验、CCK-8实验、活/死细胞染色、细菌黏附实验、组织黏附实验分别对其流变学性能、可注射性、降解性能、细胞相容性、抗细菌黏附性能和组织黏附性能进行表征。构建大鼠膝关节力学失稳模型,并分为正常组、PWN组、透明质酸组(HA组)与未治疗组,其中PWN组、HA组术后1周时注射PWN与HA进行治疗。治疗4周后取大鼠膝关节标本进行Micro-CT分析和组织学染色分析,对比评估PWN对关节软骨退变的抑制作用。结果PWN具有良好的细胞相容性和可注射性。此外,相比于HA,PWN的流变学特征更接近正常关节滑液,并且PWN具有缓慢降解的特性、更高的组织黏附性能和抗细菌黏附的能力。动物实验Micro-CT分析结果显示,PWN组软骨下骨的骨密度和骨体积/组织体积均显著高于未治疗组和HA组(P<0.05)。同时,番红快绿染色结果显示,相比于HA组,PWN组软骨表面连续性较好,未见明显破损、侵蚀,蛋白聚糖分布丰度接近正常组。结论相比于临床使用的HA产品,PWN水凝胶具有仿生正常关节滑液的流变学特征、缓慢降解的特性和较强的组织黏附性能,可延缓大鼠膝关节力学失稳下关节骨软骨的退变,有望单独或与HA联合应用于骨关节炎等关节软骨病变的临床治疗。

Objective To design and prepare an injectable hydrogel with the biomimetic rheological characteristics of a normal synovial fluid,and the effect of this hydrogel on inhibiting cartilage degeneration after knee trauma and its possible mechanism are also studied.Methods An injectable tissue adhesive hydrogel(PWN)was synthesized using polyvinyl alcohol solution,starch,and sodium chloride as the primary constituents.The rheological properties,injectability,degradability,cyto-compatibility,anti-bacterial adhesion performance,and tissue adhesion of PWN and HA injections were analyzed using rheological,injection force,in vitro degradation,CCK-8 test,Live/Dead staining,bacterial adhesion test and tissue adhesion tests.A knee joint mechanical instability model was created in rats,and 1 week post-surgery,PWN and HA were administered into the joint cavity.The rats were categorized into four groups:The normal,PWN,hyaluronic acid(HA),and non-treated groups.After four weeks of treatment,the knee joint samples of the rats underwent Micro-CT and histological staining analyses for assessing and comparing the protective effects on articular cartilage and subchondral bone in vivo.Results PWN exhibited good cell compatibility and injectability.In comparison to HA,PWN displays rheological characteristics more akin to normal joint synovial fluid.Moreover,PWN had a slow degradation behavior,enhanced tissue adhesion performance,and an anti-bacterial adhesion performance.The Micro-CT analysis results showed that the bone density and bone volume/tissue volume of subchondral bone in the PWN group were significantly higher than those in the untreated and HA groups(P<0.05).Meanwhile,compared to HA,the safranine and fast green staining results showed that the cartilage surface in the PWN group exhibited good continuity and no obvious damage or erosion,and the abundance of distributed proteoglycan was similar to that in the normal group.Conclusion Compared to clinically used HA products,the PWN displays rheological properties similar to natural synovial joint fluid,slow degradation,and superior tissue adhesion performance.This may effectively prevent the degeneration of articular cartilage and subchondral bone remodeling caused by mechanical instability in the knee joint of rats.Therefore,this hydrogel is anticipated to be utilized independently or in conjunction with HA for the clinical management of articular cartilage ailments like OA.