Silk fibroin hydrogel containing <i>Sesbania sesban</i> L. extract for rheumatoid arthritis treatment

Purpose: Rheumatoid arthritis, a chronic and progressive inflammation condition in the joints, has significantly reduced the patient quality of life and life expectancy. Crucially, there is no complete therapy for this disease, and the current treatments possess numerous side effects. Thus, novel therapeutic approach is necessary. To that end, this study developed novel silk fibroin in-situ hydrogel containing Sesbania sesban L. extract, a plant with high anti-inflammatory actions that are beneficial for rheumatoid arthritis treatments. Methods: The hydrogels were manufactured using simple method of spontaneous gelation at different temperature. The gel properties of morphology, gelation time, viscosity, gel strength, stability, drug loading capacity, drug release rate, and in-vitro anti-inflammatory activity were investigated with appropriate methods. Results: The optimal formulation had highly porous structure, with a gelation time of 0.5 h at room temperature and bodily temperature of 37 C, a viscosity of 2530 ± 50 cP, a gel strength of 1880.14 ± 35.10 g, and a physical stability of >6months. Moreover, the hydrogel contained the Sesbania sesban L. leaf extract with a total phenolic content of 92.8 ± 8.30mg GAE/g, and sustained the release rate for >20 da: ys, followed the Higuchi model. Regarding the in-vitro activities, all formulations were nontoxic to the RAW 264.7 cell line and demonstrated comparable anti-inflammatory activity to the free extract, in terms of the NO reduction levels. Conclusion: Conclusively, the systems possessed potential properties to be further investigated to become a prospective rheumatoid arthritis treatment.