Calotropis gigantea incorporated alginate dialdehyde-gelatin hydrogels for cartilage tissue regeneration in Osteoarthritis

The pursuit for better treatment modalities and regenerative approaches for degenerative diseases like osteoarthritis opens an avenue for the relevant role of plant secondary metabolites and phytochemicals. Calotropis gigantea (C. gigantea) is a multi-effective medicinal plant used in traditional and folk medicine in the Indian Oreintal region. In this context, the current study aims to fabricate C. gigantea extract (CGE) incorporated self-cross-linked alginate dialdehyde-gelatin (CGEADAG) hydrogel scaffolds for cartilage tissue regeneration in vitro. The preliminary phytochemical screening of CGE showed that it has a rich source of alkaloids, phenols, flavonoids, etc. The antioxidant potential assay and antibacterial activity of CGE proved that it also possesses myriads of antioxidants that could provide antibacterial activity. The important bioactive molecules responsible for antioxidant and antimicrobial effects are Linolenic acid methyl ester, cis-verbinol, gamma-tocopherol, and alpha-tocopherol were identified by GC-MS analysis. The FTIR-ATR analysis of CGEADAG revealed that CGE is incorporated into the ADAG hydrogel as indicated by a shift in the absorption peak at 2972 cm-1, 1538 cm-1, and 945 cm-1. The properties of self-cross-linked CGEADAG hydrogel showed a characteristic gelation time of 7.8 min, and water uptake activity of 952 +/- 31% and amino group content of 1.49 +/- 0.22 mu g/ml. The average pore size increased from 6.09 mu m in ADAG to 9.64 mu m in CGEADAG hydrogel monitored by SEM analysis. The cartilage regenerative potential of CGE and CGEADAG was demonstrated by cell proliferation assay on primary chondrocytes from rat knee joints. The developed CGEADAG hydrogel may be proposed as an antibacterial, non-immunogenic, antioxidant-rich cell-free hydrogel system to increase the efficacy of cartilage regeneration/repair in patients suffering from osteoarthritic conditions.

Automated summary

The study demonstrates that the incorporation of C. gigantea extract (CGE) with self-cross-linked alginate dialdehyde-gelatin (CGEADAG) hydrogel can be used for cartilage tissue regeneration. CGE is rich in bioactive compounds with antioxidant and antibacterial activities. The properties of CGEADAG hydrogel, such as gelation time, water uptake, and pore size, were characterized. Cell proliferation assay on primary chondrocytes showed the regenerative potential of CGE and CGEADAG. This research is important for the treatment of degenerative diseases like osteoarthritis.