A review on chitosan-gelatin nanocomposites: Synthesis, characterization and biomedical applications
In the wide range of materials available for variety of biomedical applications, the chitosan-gelatin nanocomposites are emerging rapidly. The chitosan-gelatin nanocomposites are generally synthesized by inclusion of nanoparticles into the chitosan-gelatin matrix using various cross-linking methods. Apart from acting as a matrix for dispersing nanoparticles, the chitosan-gelatin composite can work as a reducing as well as stabilizing agent for nanoparticles preventing their agglomeration. The chitosan-gelatin matrix provides a biocompatible, biodegradable, and bioactive base to synthesize the nanocomposites of biological importance. The chitosan and gelatin are usually blended to improve the biological properties of the resulting material by promoting cell adhesion and forming a polyelectrolyte complex. Apart from the chemical cross-linkages between chitosan and gelatin produced via suitable cross-linker, the functional groups of chitosan (-NH3+ and -OH) and gelatin (-NH2, -OH, -COOH/-COO?) interact through hydrogen bonding and electrostatic interactions which further improves their compatibility and chemistry. Depending upon the nature of the nanoparticles, the chitosan-gelatin nanocomposites offer numerous materials with diverse properties and a multitude of applications. The literature cited in this paper reveals that drug loading and release capacity for different drugs from chitosan-gelatin composites synthesized with different nanoparticles have been found to be more than 80%. The sustained delivery of different drugs ranging from cancer drugs-antibiotics-proteins from these nanocomposites has been observed for a time period in the range of 5–15 days. The cell adhesion efficiency and cell viability of different chitosan-gelatin nanocomposites has been observed to be more than 90% and 100%, respectively. The mechanical strength of these composites with different nanoparticles has been observed between 12.4 Pa and 16.6 MPa. In the present review paper, the authors present a critical review of the development of different types of chitosan-gelatin matrices with distinct nanoparticles (in the form of composites, films/membranes, hydrogels, scaffolds and nanospheres) and their utilization for biomedical applications such as bone tissue engineering, drug delivery, and wound healing. Subsequently, the structure-property relationship of chitosan-gelatin with nanocomposites is addressed and finally the correlation of properties of nanocomposites with their biological applications is discussed.