Synthesis and Bioactivity of Sol–Gel Derived Porous, Bioactive Glass Microspheres Using Chitosan as Novel Biomolecular Template

Abstract

This article reports a novel, simple route for synthesis of sol–gel derived porous, bioactive glass (BG) microspheres using chitosan (CTS) as a biomolecular template in the acid‐catalyzed sol–gel process. The use of CTS, which is a natural biocompatible polymer with a unique molecular structure, allowed the synthesis of BG microparticles with a spherical shape, 5–10 μm in size. Furthermore, pores with a size of 5–40 nm were created entirely throughout BG microspheres, which were formed by removing the network of CTS present initially in the CTS‐BG composite microparticles via heat‐treatment at 600°C for 2 h. These porous BG microspheres induced the vigorous precipitation of apatite crystals on their surface when immersed in simulated body fluid for 24 h, thus suggesting their excellent bioactivity .

Tailoring the Structure of Bioactive Glasses: From the Nanoscale to Macroporous Scaffolds

“…The Ca 2+ precipitation as a solid phase impedes the incorporation of this ion as network modifier within the silica matrix. For this reason, porous spherical particles with high calcium content have been prepared using methods such as microemulsions, aerosol‐assisted methods or with templates that impose spherical morphology such as chitosan microspheres . In these cases, the alkaline environment is not needed to form spheres and the acid pH allows higher calcium contents in the reaction media.…”

Hollow calcium silicate microspheres with a micro-porous structure for protein adsorption and local delivery

“…Calcium silicate has been reported to exhibit good biodegradability and osteoconductivity as a scaffold material for bone tissue engineering [7]. Until now, microspheres composed of bioceramics, such as hydroxyapatite [8,9] and bioglass [10,11], have been prepared for local drug delivery. However, the absence of open holes and the hollow structure of bioceramic microspheres have restricted their application for controlled drug release and bone regeneration [12,13].…”

Bio-templated bioactive glass particles with hierarchical macro–nano porous structure and drug delivery capability

“…BGPs via the templating of organic species [23][24][25]. As complex and elaborate structures with highly functional specificity can be found easily in nature, templating of nature species has become a versatile approach toward the fabrication of advanced materials with sophisticated structure and morphology [26][27][28].…”