Biodegradable polymer–silica xerogel composite microspheres for controlled release of gentamicin

Abstract

Single and double layered composite microspheres were prepared by encapsulating gentamicin-loaded silica xerogels with biodegradable PLGA polymers (poly(DL-lactide-co-glycolide)). The in vitro drug release properties of both the composite microspheres were investigated. The single layered composite microspheres showed a high initial burst, followed by two sustained release stages lasting for approximately 6 weeks. The two sustained release stages of the single layered composite microspheres could be attributed to the swelling and bulk erosion of the polymer encapsulations, respectively. In comparison with the single layered composite microspheres, the double layered composite microspheres realized a much reduced initial burst together with three sustained release stages. The whole release period of the double layered composite microspheres could last more than 9 weeks. These distinct behaviors make the double layered composite microspheres promising as a new drug release material for localized drug delivery applications.

Alginate–chitosan–PLGA composite microspheres induce both innate and adaptive immune response through parenteral immunization in fish

“…This result was in agreement with the use of alginateechitosanePLGA composite microsphere for hepatitis B vaccine delivery in a mice model which showed higher antibody response and persists up to one month [34]. These results also suggest fast release particles may be more effective in inducing primary immune responses, while delayed release microspheres are more effective in boosting the immune responses [37,38]. It was also hoped that the persistent antigen release would mimic the booster doses necessary for most of the nonlive vaccines [38].…”

Iron(III)-Doped, Silica Nanoshells: A Biodegradable Form of Silica

“…as biocompatible, biodegradable materials. 20, 21, 23–28 Of the materials studied, compounds that had been calcined, or sintered, at high temperatures reduced the amount of silica released or dissolved from the bulk material. 13, 19–22, 29, 30 Calcination causes the dehydration of silica and imparts it with a dense network structure.…”

Calcium carbonate microcapsules encapsulating biomacromolecules

“…We also published the preparations of silica microcapsules [15] and the direct encapsulation of biomacromolecules into them [16] by interfacial reaction method using W/O/W emulsion. However, the degradability of silica within the living body is thought to be poor and the body residue of silica might become some serious problems [17][18][19], although some recent reports revealed the comparatively high biocompatibility of silica nanoparticles [20][21][22]. Biodegradable components are predominant options of clinical and biomedical applications not only in organic polymer materials but also in porous inorganic ones.…”