PEG/POSS纳米杂化水凝胶复合材料的研制及其在人工心脏瓣膜上的应用

Tissue engineering heart valve (TEHV) theoretically can overcome the lack of mechanical valve and bioprothetic valve, and has the property of growth, thus has broad prospects for development. Polyethylene glycol (PEG) hydrogels have good biological compatibility, non-toxic, low immunogenicity, are very attractive and potential TEHV scaffold materials, but their mechanical property is too weak. Combing the advantages of PEG hydrogel and POSS nanoparticle and carrying biological signal MMP substrate peptide, this project intends to prepare PEG/POSS nanohybrid hydrogels with enzyme sensitivity and develop new TEHV scaffold materials with high swelling and mechanical properties, anti-calcification ability and tunable enzyme degradability. Several fundamental questions will be systematically addressed, including the structure-dependent properties of polymer materials, the intrinsic relationship between the physicochemical properties, biological characterization with the content of nanoparticle and proportion of crosslinker, optimal design and controllable synthesis of the hydrogel nanocomposites. The successful implementation of this project will provide some theoretical support and practical guidance to the design, preparation and application of artificial heart valve implants, undoubtedly has important scientific significance and medical application value.

组织工程心脏瓣膜(TEHV)理论上能克服机械瓣及生物瓣的不足，且具有生长性，因而具有广阔的发展前景。聚乙二醇（PEG）水凝胶生物相容性好、无毒、免疫原性低，是潜在的TEHV支架材料，但现有的PEG水凝胶机械性能太弱。本项目拟结合PEG水凝胶和POSS纳米粒子的优点，携带生物信号MMP底物肽，制备酶敏感性PEG/POSS纳米杂化水凝胶，将高分子材料与生物信号相结合构建具有高含水量、高机械性能、抗钙化能力和酶降解性的新型TEHV复合支架材料。研究聚合物结构对材料性能的影响，探讨纳米粒子含量、交联剂比例与复合材料物理化学性能及生物性能之间关系的基本规律，尝试从理论角度对复合材料的设计合成进行诠释，以期实现复合材料的可控合成。本项目的成功实施将为人工心脏瓣膜植入材料的设计、制备及其应用提供一定的理论支持和实际指导，无疑具有重要的科学意义和医学应用价值。

组织工程心脏瓣膜(TEHV)理论上能克服机械瓣及生物瓣的不足，且具有生长性，因而具有广阔的发展前景。聚乙二醇（PEG）水凝胶生物相容性好、无毒、免疫原性低，是潜在的TEHV支架材料，但现有的PEG水凝胶机械性能太弱。本项目结合PEG水凝胶和POSS纳米粒子的优点，开发新型PEG-POSS纳米杂化水凝胶复合材料，以期用于人工心脏瓣膜植入材料。首先合成了含二个、四个和八个巯基活性基团的POSS纳米粒子。单巯基POSS直接从Sigma- Adrich 公司购买。并以八巯基POSS为核，通过在POSS的八臂上引入亲水的PEG链段，合成一系列具有不同PEG链长的两亲性POSS-PEG-SH交联剂；其次，制备了6种PEG水凝胶或POSS-PEG纳米杂化水凝胶，并对它们的溶胀性能、机械性能、降解性、生物相容性及抗钙化性能进行研究；最后，通过探讨PEG分子量、成胶固含量、POSS含量以及交联剂比例对复合材料性能的影响，得到材料结构与其物理化学及生物性能之间的关系，实现材料的可控合成，为水凝胶复合材料在人工心脏瓣膜移植上的应用奠定技术基础。