Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Department of Endodontics, Stomatological Hospital, Southern Medical University, Guangzhou 510515, China.
Biomacromolecules. 2023 Jun 12;24(6):2928-2941. doi: 10.1021/acs.biomac.3c00302. Epub 2023 May 22.
Gelatin methacryloyl (GelMA) hydrogels have been extensively used for drug delivery and tissue engineering applications due to their good biocompatibility, biodegradability, and controllable photocurable efficiency. Phosphate buffer solution (PBS) is the most widely used reaction system for GelMA synthesis. However, carbonate-bicarbonate buffer solution (CBS) has been tried recently for synthesizing GelMA due to its high reaction efficiency. However, there is a lack of systematic investigation into possible differences in the structure and properties of GelMA synthesized in PBS and CBS, respectively. Therefore, in the current study, GelMA molecules with two degrees of methacryloylation (∼20 and ∼80%) were synthesized under PBS and CBS reaction systems, respectively, in comparable conditions. The results showed that because of the functionalization of methacrylate groups in gelatin chains, which could interfere with the intrachain and interchain interactions, such as hydrogen bonding, the GelMA molecules synthesized in PBS had distinct physical structures and exhibited different properties in comparison with those produced in CBS. GelMA hydrogels synthesized in PBS exhibited higher gel-sol transition temperatures and better photocurable efficiencies, mechanical strength, and biological properties. In contrast, GelMA hydrogels produced in CBS showed advantages in swelling performance and microstructures, such as pore sizes and porosities. In addition, GelMA synthesized in PBS and possessing a high degree of methacryloylation (the "GelMA-PH" polymer) showed great potential for three-dimensional (3D) bioprinting. This focused study has gained helpful new insights into GelMA and can provide guidance on the application of GelMA in 3D printing and tissue engineering.
明胶甲基丙烯酰（GelMA）水凝胶由于其良好的生物相容性、可生物降解性和可控制的光固化效率，已被广泛应用于药物输送和组织工程应用。磷酸盐缓冲溶液（PBS）是合成 GelMA 最广泛使用的反应体系。然而，由于其高反应效率，最近已经尝试使用碳酸盐-碳酸氢盐缓冲溶液（CBS）来合成 GelMA。然而，由于 PBS 和 CBS 分别合成的 GelMA 的结构和性能可能存在差异，因此缺乏系统的研究。因此，在目前的研究中，在 PBS 和 CBS 反应体系中，分别在可比条件下合成了两种程度的甲基丙烯酰化（20 和80%）的 GelMA 分子。结果表明，由于明胶链上甲基丙烯酰基团的功能化，可能会干扰分子内和分子间的相互作用，如氢键，因此在 PBS 中合成的 GelMA 分子具有明显的物理结构，并表现出与在 CBS 中合成的 GelMA 分子不同的性质。在 PBS 中合成的 GelMA 水凝胶表现出更高的凝胶-溶胶转变温度和更好的光固化效率、机械强度和生物性能。相比之下，在 CBS 中合成的 GelMA 水凝胶在溶胀性能和微观结构方面表现出优势，例如孔径和孔隙率。此外，在 PBS 中合成的具有高甲基丙烯酰化程度的 GelMA（"GelMA-PH"聚合物）在 3D 生物打印方面显示出巨大的潜力。这项重点研究为 GelMA 提供了新的有价值的见解，并为 GelMA 在 3D 打印和组织工程中的应用提供了指导。
