Institute of Composite and Biomedical Materials, National Research Council, P.le Tecchio 80, 80125, Naples, Italy.
Biomacromolecules. 2012 Nov 12;13(11):3510-21. doi: 10.1021/bm300818y. Epub 2012 Oct 30.
The requirement of a multifunctional scaffold for tissue engineering capable to offer at the same time tunable structural properties and bioactive interface is still unpaired. Here we present three-dimensional (3D) biodegradable polymeric (PCL) scaffolds with controlled morphology, macro-, micro-, and nano-mechanical performances endowed with bioactive moieties (RGD peptides) at the surface. Such result was obtained by a combination of rapid prototyping (e.g., 3D fiber deposition) and surface treatment approach (aminolysis followed by peptide coupling). By properly designing process conditions, a control over the mechanical and biological performances of the structure was achieved with a capability to tune the value of compressive modulus (in the range of 60-90 MPa, depending on the specific lay-down pattern). The macromechanical behavior of the proposed scaffolds was not affected by surface treatment preserving bulk properties, while a reduction of hardness from 0.50-0.27 GPa to 0.1-0.03 GPa was obtained. The penetration depth of the chemical treatment was determined by nanoindentation measurements and confocal microscopy. The efficacy of both functionalization and the following bioactivation was monitored by analytically quantifying functional groups and/or peptides at the interface. NIH3T3 fibroblast adhesion studies evidenced that cell attachment was improved, suggesting a correct presentation of the peptide. Accordingly, the present work mainly focuses on the effect of the surface modification on the mechanical and functional performances of the scaffolds, also showing a morphological and analytical approach to study the functionalization/bioactivation treatment, the distribution of immobilized ligands, and the biological features.
用于组织工程的多功能支架需要同时提供可调的结构性能和生物活性界面，但目前仍然难以实现这一要求。在这里，我们展示了具有受控形态、宏观、微观和纳米机械性能的三维（3D）可生物降解聚合物（PCL）支架，其表面具有生物活性部分（RGD 肽）。通过快速原型制作（例如，3D 纤维沉积）和表面处理方法（氨解后肽偶联）的组合，获得了这种结果。通过适当设计工艺条件，可以控制结构的机械和生物学性能，能够调节压缩模量的值（在 60-90 MPa 的范围内，具体取决于特定的铺设模式）。提出的支架的宏观机械性能不受表面处理的影响，保留了其整体性能，而硬度从 0.50-0.27 GPa 降低到 0.1-0.03 GPa。化学处理的渗透深度通过纳米压痕测量和共聚焦显微镜确定。通过分析定量界面处的官能团和/或肽，监测功能化和随后的生物活化的效果。NIH3T3 成纤维细胞黏附研究表明，细胞附着得到了改善，表明肽的正确呈现。因此，本工作主要集中在表面改性对支架的机械和功能性能的影响上，还展示了一种形态学和分析方法来研究功能化/生物活化处理、固定配体的分布和生物学特征。
