Biopolymer-Mimetic Worm-like Micelle Tissue Scaffolds

描述(由申请人提供)： 我们建议开发一种用于人工组织生长的新型纤维支架，它结合了合成生物材料和纤维生物聚合物的关键属性，合成生物材料允许为选择性细胞黏附量身定做的特定成分，而没有病毒或病原体传播的风险。纤维状生物聚合物凝胶，如I型胶原和纤维蛋白，允许在自组装过程中通过细胞捕获直接获得细胞性，并有助于结构和成分重建。对于蠕虫状胶束(WLM)支架的制备，我们将使用至少包含三个不同区域的嵌段共聚物：可交联性疏水核心、亲水性电晕和细胞粘附肽。疏水核在生理条件下(如聚脂肪酸酯)是可降解的。聚环氧乙烷(PEO)将作为亲水性成分，简单的细胞粘附肽将偶联到PEO末端。在与WLM在水溶液中形成细胞悬浮液后，WLMS的疏水核心将通过简单的催化交联进行化学固定，从而使细胞直接被困在由稳定但最终降解的WLM组成的缠绕网络中，类似于纤维状生物聚合物。流变学、低温透射电子显微镜和SAXS将用于验证WLM网络的完整性，并表征与细胞-网络机械相互作用相关的物理性质，当施加机械约束时，这些相互作用会导致网络收缩和对齐。两亲性嵌段共聚物的分子参数将被系统地调节，以控制WLM的形成、交联度、降解速度和最终的力学行为。将强调接近生物聚合物凝胶的相关材料特性的努力。当细胞被包裹在交联型WLM网络中时，将使用定量偏振光显微镜分析细胞诱导的网络紧凑和排列，并通过生化和组织学分析来表征WLM的降解和ECM的沉积。如果降解和沉积发生在不同的时间尺度上，将相应地调整分子量和交联剂密度，并根据需要追求各种可降解核心。将监测细胞活性和聚合物降解情况。体外孵育后的人工组织的最终机械性能、ECM组成和ECM结构将与软结缔组织进行比较。合成的人工组织将在大鼠皮下植入模型中进行测试，以评估生物相容性。

DESCRIPTION (provided by applicant): We propose to develop a novel fibrillar scaffold for artificial tissue growth that combines the key attributes of synthetic biomaterials and fibrillar biopolymers, Synthetic biomaterials allow for defined composition tailored for selective cell adhesion with no risk of viral or pathogen transmission. Fibrillar biopolymer gels, such as type I collagen and fibrin, allow cellularity to be obtained directly by cell entrapment during self-assembly and are conducive to structural and compositional remodeling. For the preparation of worm-like micelle (WLM) scaffolds we will use block copolymers that contain at least three distinct regions: a crosslinkable hydrophobic core, a hydrophilic corona, and a cell adhesion peptide. The hydrophobic core will be degradable under physiological conditions (e.g., polyaliphatic esters). Polyethylene oxide (PEO) will be used as the hydrophilic component and simple cell adhesion peptides will be conjugated to the PEO terminus. After formation of a cell suspension with the WLM in aqueous solution, the hydrophobic cores of the WLMs will be chemically fixed through simple catalytic cross linking, allowing direct cell entrapment into an entangled network of stable but ultimately degrading WLMs, analogous to the fibrillar bi0polymers. Rheometry, cryo-TEM, and SAXS will be used to verify the integrity of the WLM network and to characterize physical properties relevant to cell-network mechanical interactions that lead to network contraction and alignment when a mechanical constraint is applied. The molecular parameters of the amphiphilic block copolymers will be systematically tuned to control the WLM formation, crosslinking density, degradation rates and ultimate mechanical behavior. Efforts to approximate the relevant material properties of the biopolymer gels will be emphasized. With cells entrapped into a cross-linked WLM network, cell induced network compaction and alignment will be analyzed using quantitative polarized light microscopy, and the evolving WLM degradation and ECM deposition characterized using biochemical and histological analyses. Molecular weights and cross-link density will be adjusted accordingly, and various degradable cores will be pursued as necessary, if degradation and deposition occur on disparate time scales. Cell viability and polymer degradation will be monitored. Ultimate mechanical properties, ECM composition, and ECM structure of the artificial tissues following in vitro incubation will be compared to soft connective tissues. The resultant artificial tissues will be assayed in a rat subcutaneous implantation model to assess biocompatibility.