Effect of Gelatin on Characteristics of Enzymatically-Gellable Alginate Hydrogels for Cartilage Tissue Engineering Application

In situ formed injectable hydrogels have proved to be a promising candidate for noticeable applications such as drug delivery and tissue engineering due to their ability to fill irregularly shaped tissue imperfections, needlessly invasive surgeries, and non-immunogenicity. Alginate, a natural anionic linear polysaccharide, is one of the most common biomaterials due to its abundance, biocompatibility, and gentle cross-linking procedure. To improve the mechanical stability, it is necessary to modify the structure of common alginate. Modification of alginate with phenol moieties (Alg-Ph), which can be gel enzymatically with horseradish peroxidase (HRP) along with H2O2 as an electron donor, can increase alginate hydrogel stability in the cell culture medium. In this work, alginate was modified by tyramine hydrochloride in the presence of EDC/NHS for 1 day at 25°C. To provide mammalian cell adhesive, gelatin was added to the enzymatically-gellable alginate and the obtained hydrogel (Alg-Ph-Gel) was characterized by SEM, gelation time, enzymatic degradation, mechanical and swelling properties as well as water vapor loss for use in cartilage tissue engineering applications. Chondrocyte at X0 = 2×〖10〗^6 cells/ml gel was cultured for 14 days and MTT assay was used for cell activity measurements. SEM images showed the addition of gelatin could increase the uniformity of the pore sizes inside the Alg-Ph-Gel hydrogels. Alg-Ph-Gel hydrogels also showed higher gelation time, degradation rate, as well as swelling properties as the hydrogels, swelled 1.6- fold more than the Alg-Ph hydrogels after 72 h in PBS. However, mechanical strength, as well as water vapor loss, decreased for the Alg-Ph-Gel hydrogels. Chondrocyte cells cultured in the Alg-Ph-Gel hydrogels could maintain their original phenotype and proliferate more than1.4-fold higher than the cells cultured in the Alg-Ph hydrogels after 14 days (p < 0.05). The study demonstrates that gelatin can improve the enzymatically-gellable alginate hydrogels for cartilage tissue engineering application

کلیدواژه ها:

Alginate ، Hydrogel Scaffold ، Alginate Modification ، Gelatin ، Tissue Engineering ،