Nanoscale clustering of RGD peptides at surfaces using comb polymers. 2. Surface segregation of comb polymers in polylactide
Nanoscale clustering of RGD peptides at surfaces using comb polymers. 2. Surface segregation of comb polymers in polylactide
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DOI：
10.1021/bm015510f
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发表时间：
2001-06-01
影响因子：
6.2
通讯作者：
Griffith, LG
中科院分区：
文献类型：
--
作者：
Irvine, DJ;Ruzette, AVG;Griffith, LG
这些研究的第1部分描述了聚（甲基丙烯酸甲酯-r-聚氧乙烯甲基丙烯酸酯）P（MMA-r-POEM）梳形聚合物，其在蛋白质抗性背景上以纳米级簇的形式在表面呈现Arg-Gly-Asp（RGD）肽，用于控制细胞粘附。在第2部分中，我们研究了这些肽改性和未改性的梳形聚合物与聚乳酸（PLA）共混的表面分离，作为一种自组装方法，适用于多孔组织工程支架的表面改性。梳形聚合物的表面富集的多个热力学驱动力被利用通过退火PLA/P（MMA-r-POEM）共混物高于共混物组分的玻璃化转变温度但低于PLA的熔点，同时与水接触。使用自洽场（SCF）晶格模型的退火共混物的界面组成分布的预测。计算预测的梳状在顶部类似于50埃，共混物，和准二维构象的梳状分子在界面处的组织，类似于第1部分中描述的纯梳状表面与水接触的表观结构的强烈富集。在实验上，PLA/梳状共混物表面的接触角测量，XPS，定量的配体簇表面密度和稳定性的AFM和荧光纳米球标记，和细胞附着试验。这些数据是一致的SCF预测，显示出显着丰富的梳在水退火的表面和RGD簇密度一致的二维构象的梳分子在表面层。通过动态流变仪、小角中子散射、DSC和X射线衍射研究验证了共混物的本体相容性。表面隔离梳提供了可调的细胞粘附在PLA上通过表面本地化的RGD纳米簇顶部的耐细胞背景。
Part 1 of these studies described poly(methyl methacrylate-r-polyoxyethylene methacrylate) P(MMA-r-POEM) comb polymers that present Arg-Gly-Asp (RGD) peptides at a surface in nanoscale clusters on a protein-resistant background for control of cell adhesion. Here in part 2, we examine surface segregation of these peptide-modified and unmodified comb polymers blended with polylactide (PLA) as a self-assembly approach suitable for surface modification of porous tissue engineering scaffolds. Multiple thermodynamic driving forces for surface enrichment of the comb polymer are exploited by annealing PLA/P(MMA-r-POEM) blends above the glass transition of the blend components but below the melting point of PLA, while in contact with water. Predictions of the interfacial composition profiles of annealed blends were made using a self-consistent field (SCF) lattice model. The calculations predict strong enrichment of the comb in the top similar to50 Angstrom, of blends, and organization of comb molecules in quasi-2D conformations at the interface, similar to the apparent structure of pure comb surfaces in contact with water described in part 1. Experimentally, PLA/comb blend surfaces were characterized by contact angle measurements, XPS, quantification of ligand-cluster surface density and stability by AFM and fluorescent nanosphere labeling, and cell attachment assays. These data were consistent with SCF predictions, showing significant enrichment of the comb at water-annealed surfaces and RGD cluster densities consistent with 2D conformations for comb molecules in the surface layer. Bulk miscibility of the blends was verified by dynamic rheometry, small-angle neutron scattering, DSC and X-ray diffraction studies. Surface segregation of combs provided tunable cell adhesion on PLA through surface-localized nanoclusters of RGD atop a cell-resistant background.