College of Chemistry, Zhengzhou University, Zhengzhou, China.
J Biomater Sci Polym Ed. 2023 Oct;34(13):1771-1792. doi: 10.1080/09205063.2023.2182577. Epub 2023 Feb 23.
A series of mussel-inspired pH-responsive self-healing hydrogels based on gelatin crosslinked by oxidized tannic acid (GLT-OTAs) were prepared and used as controlled drug delivery systems (CDDS). An antiphlogistic drug, indomethacin (IDMC) was used as model drug to be immobilized into the hydrogels. The obtained hydrogel samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical stability, biocompatibility and self-healing property of the hydrogels were estimated, respectively. Swelling and drug release behaviors of these hydrogels were measured in phosphate buffered saline (PBS) with pH 7.4 (simulated intestinal fluid) and HCl solution with pH 1.2 (simulated gastric fluid) at 37 °C. Effect of the OTA content on the structures and characteristics of all samples was discussed. FTIR spectra revealed the covalent cross-linking between gelatin and OTA induced by Michael addition and Schiff base reaction. Both XRD and FTIR all showed the drug (IDMC) was loaded successfully and existed steadily. GLT-OTA hydrogels had satisfactory biocompatibility, superior self-healing. Results also illustrated that the mechanical strength, internal structure, the swelling and drug release behaviors of the GLT-OTAs hydrogel were greatly affected by the OTA content. With increasing the OTA content, the mechanical stability of GLT-OTAs hydrogel became better and better, and their internal structure became more and more compact. The swelling degree (SD) and cumulative drug release of all hydrogel samples tended to decrease with increasing OTA content and both had obvious pH responsiveness. For each hydrogel sample, the cumulative drug release in PBS at pH 7.4 was greater than that in HCl solution at pH 1.2. These results indicated that the obtained GLT-OTAs hydrogel had promising potential to be used as effective pH-responsive and self-healing drug delivery materials.
一系列基于氧化单宁酸（GLT-OTAs）交联明胶的贻贝启发型 pH 响应自修复水凝胶被制备并用作控制药物释放系统（CDDS）。将一种抗炎药吲哚美辛（IDMC）用作模型药物固定在水凝胶中。通过傅里叶变换红外（FTIR）光谱、X 射线衍射（XRD）和扫描电子显微镜（SEM）对所得水凝胶样品进行了表征。分别评估了水凝胶的机械稳定性、生物相容性和自修复性能。在 37°C 下，在 pH 7.4（模拟肠液）的磷酸盐缓冲盐水（PBS）和 pH 1.2（模拟胃液）的 HCl 溶液中测量了这些水凝胶的溶胀和药物释放行为。讨论了 OTA 含量对所有样品结构和特性的影响。FTIR 光谱表明，明胶和 OTA 之间通过迈克尔加成和希夫碱反应发生了共价交联。XRD 和 FTIR 均表明成功负载了药物（IDMC）且存在稳定。GLT-OTA 水凝胶具有良好的生物相容性和优越的自修复性能。结果还表明，GLT-OTAs 水凝胶的机械强度、内部结构、溶胀和药物释放行为受 OTA 含量的影响很大。随着 OTA 含量的增加，GLT-OTAs 水凝胶的机械稳定性越来越好，内部结构越来越紧密。所有水凝胶样品的溶胀度（SD）和累积药物释放均随 OTA 含量的增加而降低，且均具有明显的 pH 响应性。对于每种水凝胶样品，在 pH 7.4 的 PBS 中的累积药物释放量均大于在 pH 1.2 的 HCl 溶液中的累积药物释放量。这些结果表明，所获得的 GLT-OTAs 水凝胶具有作为有效 pH 响应和自修复药物输送材料的潜力。
