Departments of Materials Science and Engineering and Pathobiology, The University of Tennessee, Knoxville, TN 37996, USA.
Biomacromolecules. 2010 Oct 11;11(10):2748-59. doi: 10.1021/bm1008102.
To investigate the role of chemical cross-links in regulating biomaterial properties and cell behavior, we have prepared and characterized a series of biodegradable polymer blends in both un-cross-linked and photo-cross-linked forms. In this comparative study, these blends consisted of an oligomeric, cross-linkable, amorphous poly(propylene fumarate) (PPF) and a high-molecular-weight, semicrystalline poly(ε-caprolactone) (PCL). After cross-linking, semi-interpenetrating polymer networks (semi-IPNs) were formed by combining PPF chemical network and PCL physical network that was associated by the crystallites. The material design strategy presented here was different from previously studied semicrystalline polymer networks, in which crystallizable segments participated covalently in the chemical network and were significantly suppressed by the network. For these PPF/PCL blends, thermal properties such as melting temperature (T(m)) and crystallinity have been correlated with their rheological and mechanical properties to demonstrate the effects of cross-linking density and crystallinity. Surface morphology, hydrophilicity, and the capability of adsorbing proteins from cell culture media have also been determined. For potential applications in bone and vascular tissue engineering and demonstration of regulating cell behavior on polymer substrates with controllable physicochemical characteristics, in vitro cell studies that included cell viability, attachment, spreading, and proliferation have been performed using mouse MC3T3 cells and primary rat aortic smooth muscle cells (SMCs). In a similar manner, these two cell types have been found to show distinct cell responses to the polymer substrates in the presence or absence of cross-links.
为了研究化学交联在调节生物材料性能和细胞行为方面的作用，我们制备并表征了一系列可生物降解的聚合物共混物，包括未交联和光交联形式。在这项对比研究中，这些共混物由一种低分子、可交联、无定形的聚（反丁烯二酸丙二醇酯）（PPF）和高分子量、半结晶的聚（ε-己内酯）（PCL）组成。交联后，通过结合 PPF 化学网络和 PCL 物理网络形成半互穿聚合物网络（semi-IPN），后者通过晶区相关联。这里提出的材料设计策略与以前研究的半结晶聚合物网络不同，其中可结晶段通过共价键参与化学网络，并被网络显著抑制。对于这些 PPF/PCL 共混物，热性能（如熔点（Tm）和结晶度）与它们的流变和力学性能相关联，以证明交联密度和结晶度的影响。还确定了表面形貌、亲水性和从细胞培养基中吸附蛋白质的能力。为了在骨和血管组织工程中潜在应用，并展示对具有可控物理化学特性的聚合物基底调节细胞行为的能力，使用小鼠 MC3T3 细胞和原代大鼠主动脉平滑肌细胞（SMCs）进行了体外细胞研究，包括细胞活力、附着、扩散和增殖。以类似的方式，这两种细胞类型在存在或不存在交联的情况下对聚合物基底表现出明显不同的细胞反应。
