Effect of chromium(III) gallate complex on stabilization of collagen.

To improve the stability of the collagen, here we studied the interaction of chromium(III) polyphenolic complex, [Cr(GA)2 ] (GA: Gallic acid) with collagen using various spectroscopic techniques. Circular dichroism studies show that the [Cr(GA)2 ] and gallic acid did not induce any structural perturbations on the triple helix of the collagen. Both differential scanning calorimetric(DSC) data and micro-shrinkage temperature studies showed that [Cr(GA)2 ] stabilized the collagen by 6±1°C compared to gallic acid. Hydrodynamic studies revealed that the viscosity of collagen drastically reduced in the presence of [Cr(GA)2 ] while gallic acid did not. Fibrillation assay displayed a significant delay in fibril formation with Cr(III) complex compared to gallic acid treated collagen. The inhibition of fibril formation was further confirmed by microscopic data in which collagen fibres are seen with GA while [Cr(GA)2 ] treated collagen exhibit a thin microfibrils. From AFM studies, the d-periodicity of collagen was found to be decreased with [Cr(GA)2 ] while increased with gallic acid. The present study deliberate the advantage of metal complex containing polyphenolic ligand as crosslinking agent due to its synergistic effect of both metal center as well as polyphenolic groups in the stabilization of collagen structure.