Nanoporous silicon microparticles embedded into oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for enhanced controlled drug delivery

Oxidized hyaluronic acid cross-linked with adipic acid dihydrazide (oxi-HA/ADH) forms an injectable and biocompatible hydrogel suitable for treatment of musculoskeletal diseases and for drug delivery applications. In that sense, nanoporous silicon (nPSi) can be combined with biopolymers, such as oxi-HA/ADH hydrogel, to display new characteristics, which are not exhibited by the individual constituents alone. Under this context, in this work nPSi microparticles at concentrations from 0.1% to 1% m/v were embedded into oxi-HA/ADH hydrogel to improve its mechanical stability and enhance its control over drug release kinetics using Rose Bengal (RB) as a model drug because its cytotoxic effect in different cancer cell lines and tumors has been previously reported. Our results showed, for both compressive force and stress strength tests, that oxi-HA/ADH hydrogel with 1% nPSi microparticles doubled the values of control samples. Moreover, samples of oxi-HA/ADH with nPSi microparticles improved RB release kinetics control over pure oxi-HA/ADH hydrogel. Finally, the cell viability of nPSi microparticles embedded into oxi-HA/ADH hydrogel was confirmed using fibroblasts.