Mercado-Pagán Ángel E, Ker Dai Fei Elmer, Yang Yunzhi
Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA.
Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
J Biomater Appl. 2014 Oct;29(4):557-65. doi: 10.1177/0885328214537541. Epub 2014 Jun 9.
One of the main challenges for clinical implementation of small diameter vascular grafts (SDVGs) is their limited hemocompatibility. Important design specifications for such grafts include features that minimize the long-term risks of restenosis, fouling, and thrombus formation. In our lab, we have developed elastomeric hollow fiber membranes (HFMs), using a phase inversion method, as candidates for SDVGs. Here, we present our results for in vitro hemocompatibility testing of our HFM under flow and static conditions. Our results showed that the polymer-based HFMs do not damage the integrity of human red blood cells (RBCs) as shown by their low hemolytic extent (less than 2%). When analyzed for blood cell lysis using lactate dehydrogenase (LDH) activity as an indicator, no significant differences were observed between blood exposed to our HFMs and uncoagulated blood. Analysis of protein adsorption showed a low concentration of proteins deposited on the surfaces of HFM after 24 h. Platelet adhesion profiles using human platelet-rich plasma (PRP) showed that a low level of platelets adhered to the HFMs after 24 h, indicating minimal thrombotic potential. Under the majority of conditions, no significant differences were observed between medical-grade polymers and our HFMs. Eventual optimization of hemocompatible elastomeric HFM vessel grafts could lead to improved tissue vascularization as well as vascularized, tissue-engineered scaffolds for organ repair.
小口径血管移植物（SDVGs）临床应用的主要挑战之一是其血液相容性有限。此类移植物的重要设计规格包括能够将再狭窄、污垢形成和血栓形成的长期风险降至最低的特征。在我们实验室，我们采用相转化法开发了弹性体中空纤维膜（HFMs），作为小口径血管移植物的候选材料。在此，我们展示了我们的中空纤维膜在流动和静态条件下体外血液相容性测试的结果。我们的结果表明，基于聚合物的中空纤维膜不会破坏人类红细胞（RBCs）的完整性，其溶血程度较低（小于2%）。以乳酸脱氢酶（LDH）活性作为指标分析血细胞裂解情况时，暴露于我们的中空纤维膜的血液与未凝固血液之间未观察到显著差异。蛋白质吸附分析表明，24小时后沉积在中空纤维膜表面的蛋白质浓度较低。使用富含人类血小板的血浆（PRP）进行的血小板黏附分析表明，24小时后仅有少量血小板黏附在中空纤维膜上，表明血栓形成潜力极小。在大多数情况下，医用级聚合物与我们的中空纤维膜之间未观察到显著差异。最终优化具有血液相容性的弹性体中空纤维膜血管移植物可能会改善组织血管化以及用于器官修复的血管化组织工程支架。
