RESUMO
Researchers are keen on formulating composites blending biomacromolecules with functional nanoparticles to achieve greater efficacy to expedite the wound healing process. In the present work, we have engineered a genipin cross-linked gelatin hydrogel composite containing optimized concentration of cerium oxide nanoparticles (G-ONp) for the purpose of wound healing. The concentration of cerium oxide nanoparticles in G-ONp has been optimized to be 250 µg/mL, which shows more than 80% cell viability in cytotoxicity study. X-ray diffractogram of ONp displays characteristic lattice planes of cubic fluorite structure, and transmission electron micrograph reveals that the particles are sized between 2.5-6.5 nm. The genipin dimeric cross-linkage in G-ONp has been confirmed by UV-vis peak at 603 nm. Swelling ratio of G-ONp (25.3 ± 1.2) has been found to be three-fold to that of native gelatin (9.2 ± 1.4). As far as pore size distribution is concerned, lyophilized sponges of gelatin and G-ONp had microsized pores in the range of 1-140 µm and 1-19 µm, respectively, and hydrogels of the same determined by thermoporometry had nanosized pores in the range of 7-48 nm and 7-24 nm, respectively. The in vivo wound healing and histological examination have revealed that G-ONp treated rat group has shown more infiltration of leukocytes and larger deposition of collagen when compared to gelatin and control groups and has healed the wound in 12 days. These findings suggest that the composite of G-ONp is superior to gelatin in increasing wound healing and can be envisaged as a wound dressing material in future.
RESUMO
Proteins grafted with antioxidant molecules have drawn much attention due to their increased life time and biocompatibility. When protein macromolecules are cross linked chemically and physically with antioxidant molecules, they can act as antioxidant biomaterials as well as scaffolds to release the antioxidant molecules by diffusion. In our work, we have attempted to release catechin molecules from the matrix of glutathione grafted gelatin. Conjugation of glutathione and cross linkage was done by carbodiimide method to achieve smaller pores in the gelatin matrix and the characterization was performed by means of FTIR-ATR and calorimetric analyses. The glutathione grafted gelatin (GGSH) has been shown to have more thermal stability and pores with lesser radii than blank gelatin (bGEL). Free radical scavenging activity of GGSH was also found to be more than that of bGEL. Catechin was added to GGSH and bGEL by physical blending in order to achieve short term release of antioxidant molecules. CD spectra revealed that significant conformational changes occurred in secondary structure of gelatin upon interaction with catechin. Slower rate of catechin release from GGSH reflected the influence of cross linkage and physical interactive forces on the drug release properties. We conclude that the mixture of catechin with GGSH can be a potent antioxidant biomaterial releasing catechin at slower rate than the mixture of catechin with bGEL.
