Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey, USA.
Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD, USA.
J Biomed Mater Res B Appl Biomater. 2021 Feb;109(2):193-200. doi: 10.1002/jbm.b.34691. Epub 2020 Aug 4.
A biocompatible and biodegradable scaffold with load-bearing ability is required to enhance the repair of bone defects by facilitating the attachment, and proliferation of cells, and vascularization during new bone formation. However, it is challenging to maintain the porosity and biodegradability, as well as mechanical properties (especially compressive strength), at the same time. Therefore, in the present work, a biodegradable composite structure of poly(caprolactone) (PCL) was designed using compression molding with varying amounts of poly(glycolic acid) (PGA) (25, 50, 75 wt%) and fixed amount (20 wt%) of beta tricalcium phosphate (beta TCP). It was hypothesized that the fabricated composite structure will develop porosity during the degradation of the PGA and that the corresponding decrease in mechanical properties will be compensated by new bone formation and ingrowth, in vivo. Accordingly, we have systematically studied the effects of sample composition on time-dependent dissolution and mechanical properties of the PGA/beta TCP scaffolds. The compressive strength increased up to ~92 MPa at 50% compression of the designed PCL-PGA samples. Furthermore, the dissolution rate, as well as weight loss, was observed to increase with an increase in the PGA amount in PCL. Based on the mechanical properties and dissolution data, it is concluded that the PCL-PGA scaffolds with beta TCP can be suitable candidates for bone tissue engineering applications, specifically for the reconstruction of bone defects, where strength and biodegradation are both important characteristics.
一种具有生物相容性和可生物降解能力的支架，需要能够促进细胞的附着、增殖和新骨形成过程中的血管生成，从而增强对骨缺损的修复作用。然而，同时保持多孔性、生物降解性和机械性能（尤其是抗压强度）具有挑战性。因此，在本工作中，使用压缩成型设计了一种聚己内酯（PCL）的可生物降解复合材料结构，其中聚（乙醇酸）（PGA）（25、50、75wt%）的含量不同，并且固定含量（20wt%）为β-磷酸三钙（β-TCP）。假设在 PGA 降解过程中制造的复合结构将形成多孔性，并且机械性能的相应下降将通过新骨形成和内生长来补偿，在体内。因此，我们系统地研究了样品组成对 PGA/β-TCP 支架的时变溶解和机械性能的影响。在设计的 PCL-PGA 样品的 50%压缩下，抗压强度增加到约 92MPa。此外，随着 PCL 中 PGA 含量的增加，溶解速率和重量损失也观察到增加。基于机械性能和溶解数据，可以得出结论，具有β-TCP 的 PCL-PGA 支架可作为骨组织工程应用的候选材料，特别是在需要强度和生物降解性都很重要的骨缺损重建中。
