Functionalized amino acid-based injectable hydrogels for sustained drug delivery

Drug delivery vehicles optimize therapeutic outcomes by enhancing drug efficacy, minimizing side effects, and providing controlled release. Injectable hydrogels supersede conventional ones in the field of drug delivery owing to their less invasive administration and improved targeting. However, they face challenges such as low biodegradability and biocompatibility, potentially compromising their effectiveness. To address these limitations, a modified amino acid-based pH-responsive injectable shear-thinning hydrogel <i>cl</i>-β-CD-<i>g</i>-p(Gly-MA) has been developed as an efficient drug carrier. In the two-step synthetic approaches, first, the well-known amino acid glycine (Gly) is modified to form glycine methacrylate (Gly-MA). Afterward, Gly-MA is chemically crosslinked with β-cyclodextrin (β-CD), an oligosaccharide, using an ethylene glycol dimethacrylate (EGDMA) crosslinker. The presence of these biomaterials as building blocks enhances the biocompatibility, hemocompatibility, and biodegradability of the hydrogel. They also reduce the risk of immunogenicity. The unique property of easy injectability enables minimally invasive administration. This feature also helps prolong drug retention at the target site, further optimizing drug delivery efficiency. Moreover, the pH-responsive feature of the developed <i>cl</i>-β-CD-<i>g</i>-p(Gly-MA) hydrogel ensures controlled drug release in response to the physiological conditions of the target site, enhancing therapeutic efficacy. The study focuses on investigating the <i>in vitro</i> loading and release of diclofenac sodium (DS), a non-steroidal anti-inflammatory drug (NSAID) commonly used to treat arthritic pain and inflammation.