Department of Life Sciences and Medical Biosciences, Graduate School of Advanced Science and Engineering, Waseda University, TWIns 2-2, Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
J Biomater Appl. 2012 Aug;27(2):131-41. doi: 10.1177/0885328210394470. Epub 2011 Feb 22.
Recently, biomaterials have been widely used in a variety of medical applications. We previously reported that a poly-l-lactic acid (PLLA) nanosheet shows anti-adhesive properties and constitutes a useful biomaterial for preventing unwanted wound adhesion in surgical operations. In this article, we examine whether the PLLA nanosheet can be specifically modified with biomacromolecules on one surface only. Such an approach would endow each side of the nanosheet with discrete functions, that is anti-adhesive and pro-healing properties. We fabricated two distinct PLLA nanosheets: (i) collagen cast on the surface of a PLLA nanosheet (Col-Cast-PLLA) and (ii) collagen spin-coated on the nanosheet (Col-Spin-PLLA). In the Col-Spin-PLLA nanosheet, the collagen layer had a thickness of 5-10 nm on the PLLA surface and displayed increased hydrophilicity compared to both PLLA and Col-Cast-PLLA nanosheets. In addition, atomic force microscopy showed disorganized collagen fibril formation on the PLLA layer when covered using the spin-coating method, while apparent bundle formations of collagen were formed in the Col-Cast-PLLA nanosheet. The Col-Spin-PLLA nanosheet provided a microenvironment for cells to adhere and spread. By contrast, the Col-Cast-PLLA nanosheet displayed reduced cell adhesion compared to the Col-Spin-PLLA nanosheet. Consistent with these findings, immunocytochemical analysis clearly showed fine networks of actin filaments in cells cultured on the Col-Spin-PLLA, but not the Col-Cast-PLLA nanosheet. Therefore, the Col-Spin-PLLA nanosheet was shown to be more suitable for acting as a scaffold. In conclusion, we have succeeded in developing a heterofunctional nanosheet comprising a collagen modified side, which has the ability to rapidly adhere cells, and an unmodified side, which acts as an adhesion barrier, by using a spin-coating technique.
最近，生物材料已广泛应用于各种医学应用。我们之前曾报道过，聚左旋乳酸（PLLA）纳米片具有抗粘连特性，是一种用于防止手术过程中不必要的伤口粘连的有用生物材料。在本文中，我们研究了 PLLA 纳米片是否只能在一个表面上被特定的生物大分子修饰。这种方法将使纳米片的每一侧都具有离散的功能，即抗粘连和促进愈合的特性。我们制备了两种不同的 PLLA 纳米片：（i）胶原蛋白浇铸在 PLLA 纳米片表面上（Col-Cast-PLLA）和（ii）胶原蛋白旋涂在纳米片上（Col-Spin-PLLA）。在 Col-Spin-PLLA 纳米片中，胶原层在 PLLA 表面上的厚度为 5-10nm，与 PLLA 和 Col-Cast-PLLA 纳米片相比，其亲水性增加。此外，原子力显微镜显示，当使用旋涂法覆盖 PLLA 层时，胶原原纤维的形成变得无序，而在 Col-Cast-PLLA 纳米片中，则形成了明显的胶原束。Col-Spin-PLLA 纳米片为细胞附着和扩展提供了微环境。相比之下，Col-Cast-PLLA 纳米片与 Col-Spin-PLLA 纳米片相比，细胞黏附减少。与这些发现一致，免疫细胞化学分析清楚地显示，在 Col-Spin-PLLA 上培养的细胞中形成了精细的肌动蛋白丝网络，但在 Col-Cast-PLLA 纳米片中则没有。因此，Col-Spin-PLLA 纳米片更适合作为支架。总之，我们成功地使用旋涂技术开发了一种包含胶原修饰侧的杂化功能纳米片，该侧具有快速黏附细胞的能力，而未修饰的侧则作为粘连屏障。
