Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Japan.2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan Bangkok 10330, Thailand.
ACS Biomater Sci Eng. 2024 Jul 8;10(7):4245-4258. doi: 10.1021/acsbiomaterials.4c00681. Epub 2024 Jun 12.
Most hydrogels have poor mechanical properties, severely limiting their potential applications, and numerous approaches have been introduced to fabricate more robust and durable examples. However, these systems consist of nonbiodegradable polymers which limit their application in tissue engineering. Herein, we focus on the fabrication and investigate the influence of hydrophobic segments on ionic cross-linking properties for the construction of a tough, biodegradable hydrogel. A biodegradable, poly(γ-glutamic acid) polymer conjugated with a hydrophobic amino acid, l-phenylalanine ethyl ester (Phe), together with an ionic cross-linking group, alendronic acid (Aln) resulting in γ-PGA-Aln-Phe, was initially synthesized. Rheological assessments through time sweep oscillation testing revealed that the presence of hydrophobic domains accelerated gelation. Comparing gels with and without hydrophobic domains, the compressive strength of γ-PGA-Aln-Phe was found to be six times higher and exhibited longer stability properties in ethylenediaminetetraacetic acid solution, lasting for up to a month. Significantly, the contribution of the hydrophobic domains to the mechanical strength and stability of ionic cross-linking properties of the gel was found to be the dominant factor for the fabrication of a tough hydrogel. As a result, this study provides a new strategy for mechanical enhancement and preserves ionic cross-linked sites by the addition of hydrophobic domains. The development of tough, biodegradable hydrogels reported herein will open up new possibilities for applications in the field of biomaterials.
大多数水凝胶的机械性能较差，严重限制了它们的潜在应用，因此人们引入了许多方法来制造更坚固和更耐用的水凝胶。然而，这些系统由不可生物降解的聚合物组成，这限制了它们在组织工程中的应用。在此，我们专注于制造工艺，并研究疏水区段对离子交联性能的影响，以构建坚韧、可生物降解的水凝胶。首先合成了一种可生物降解的聚（γ-谷氨酸）聚合物，该聚合物与疏水性氨基酸 l-苯丙氨酸乙酯（Phe）偶联，并带有离子交联基团，即阿仑膦酸（Aln），得到γ-PGA-Aln-Phe。通过时间扫描振荡测试进行流变学评估表明，疏水区段的存在加速了凝胶化。比较具有和不具有疏水区段的凝胶，γ-PGA-Aln-Phe 的压缩强度高 6 倍，在乙二胺四乙酸溶液中的稳定性也更长，可持续长达一个月。重要的是，发现疏水区段对凝胶离子交联性能的机械强度和稳定性的贡献是制造坚韧水凝胶的主要因素。因此，本研究为机械增强提供了一种新策略，并通过添加疏水区段保留了离子交联位点。本文报道的坚韧、可生物降解水凝胶的开发将为生物材料领域的应用开辟新的可能性。
