Rational design and engineering of carbon nano-onions reinforced natural protein nanocomposite hydrogels for biomedical applications.

In the current study, poly 4-hydroxyphenyl methacrylate-carbon nano-onions (PHPMA-CNOs = f-CNOs) are synthesized and reinforced with natural protein gelatin (GL) to engineer GL/f-CNOs composite hydrogels under the sonochemical method. The influence of f-CNOs content on the mechanical properties of hydrogels is examined. Cytotoxicity of hydrogels is measured with the human osteoblast cells. The results revealed good cell viability, cell growth, and attachment on the surface of the hydrogels, and results are f-CNOs dose-dependent. Specifically, the GL/f-CNOs (2 mg/mL) hydrogel showed the highest cell viability, enhanced tensile strength, elastic modulus, and yield strength as compared to pristine GL and GL/f-CNOs (1 mg/mL) hydrogels. It reveals the extent of physisorption and degree of colloidal stability of f-CNOs within the gel matrix. Furthermore, GL/f-CNOs hydrogels efficiently load the 5-fluorouracil (5-FU) and show a pH-responsive sustained drug release over 15 days. Nevertheless, these CNOs based composite hydrogels offer a potential prospect to use them in diverse biomedical applications.