Liu Yang, Yang Tan Timothy Thatt, Yuan Shaojun, Choong Cleo
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 - Singapore.
J Mater Chem B. 2013 Jan 14;1(2):157-167. doi: 10.1039/c2tb00014h. Epub 2012 Oct 18.
Pre-vascularization of scaffolds using endothelial cells (ECs) and preservation of hemocompatibility are effective strategies to improve the long-term viability of tissue engineered constructs. The current work reports a multifunctional titanium (Ti) surface for simultaneous enhancement of EC selectivity while preserving hemocompatibility. This is achieved by REDV conjugation on surface-grafted PEGMA polymer brushes via surface-initiated atom transfer radical polymerization (ATRP) on a dopamine (DOPA)-modified Ti surface. Our results showed that the proliferation and attachment of human umbilical vein endothelial cells (HUVECs) were substantially improved by P(PEGMA)-REDV conjugation compared to pristine Ti surfaces, whilst no significant effects were observed for the mesenchymal stem cells (MSCs), thus confirming the selectivity of REDV for ECs. Platelets adhesion assay further revealed that the immobilization of PEGMA polymer brushes led to the amelioration of surface hemocompatibility, and this enhancement was not negated by the conjugation of REDV. The current multifunctional Ti-surface can potentially be useful in tissue engineered constructs for bone and dental applications as it allows for early and selective EC attachment and improved hemocompatibility whilst at the same time supporting MSC proliferation and growth.
利用内皮细胞（ECs）对支架进行预血管化以及保持血液相容性是提高组织工程构建体长期存活率的有效策略。当前的工作报道了一种多功能钛（Ti）表面，可在保持血液相容性的同时增强EC选择性。这是通过在多巴胺（DOPA）修饰的Ti表面上通过表面引发的原子转移自由基聚合（ATRP）在表面接枝的聚甲基丙烯酸乙二醇酯（PEGMA）聚合物刷上进行REDV偶联来实现的。我们的结果表明，与原始Ti表面相比，通过P(PEGMA)-REDV偶联，人脐静脉内皮细胞（HUVECs）的增殖和附着得到了显著改善，而间充质干细胞（MSCs）未观察到显著影响，从而证实了REDV对ECs的选择性。血小板黏附试验进一步表明，PEGMA聚合物刷的固定化导致表面血液相容性得到改善，并且REDV的偶联并未否定这种增强作用。当前的多功能Ti表面在骨和牙科应用的组织工程构建体中可能具有潜在用途，因为它允许早期和选择性的EC附着并改善血液相容性，同时支持MSC的增殖和生长。
