Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Biomacromolecules. 2010 Mar 8;11(3):769-75. doi: 10.1021/bm901373x.
We present the preparation and characterization of viscoelastic formulations of hyaluronic acid functionalized with polymerizable methacrylate groups. We explored three different processing strategies for controlling microstructure and interchain interactions: lightly cross-linked near-gels, emulsion-cross-linked microspheres, and an elastic microgel formed through centrifuging the microspheres. The component structure and rheological properties of these formulations were compared to those of high molecular weight hyaluronic acid solutions, which displayed classical behavior of high molecular weight polymer solutions reported by other investigators. We demonstrate that these processing strategies allow the tuning of solution properties from strongly viscoelastic behavior, observed in lightly cross-linked near-gels and concentrated microsphere solutions to elastic behavior in elastic microgels, behaving like pseudoplastic liquids having a well-defined yield stress above which viscous behavior was observed. In the centrifuged microspheres, the hyaluronic acid degree of methacrylation was inversely proportional to the gel elasticity, and a mechanism based on failure due to microsphere brittleness is proposed to explain this behavior. These results suggest that processing methacrylated hyaluronic acid can lead to a diversity of solution properties, providing methods for delivering this biologically active polymer in a broad range of applications.
我们介绍了具有可聚合甲基丙烯酰基官能化的透明质酸的黏弹性制剂的制备和表征。我们探索了控制微观结构和链间相互作用的三种不同加工策略：轻度交联的类凝胶、乳液交联的微球和通过离心微球形成的弹性微凝胶。这些制剂的组分结构和流变性能与高分子量透明质酸溶液进行了比较，后者表现出其他研究者报道的高分子量聚合物溶液的典型行为。我们证明，这些加工策略允许从轻度交联的类凝胶和高浓度的微球溶液中观察到的强黏弹性行为，调整溶液性质，到弹性微凝胶中的弹性行为，表现为具有明确定义屈服应力的假塑性液体，在屈服应力以上观察到粘性行为。在离心微球中，透明质酸的甲基丙烯酰化程度与凝胶弹性成反比，并且提出了一种基于微球脆性失效的机制来解释这种行为。这些结果表明，处理甲基丙烯酰化透明质酸可以导致多种溶液性质，为在广泛的应用中输送这种生物活性聚合物提供了方法。
