Abstract:

Mesoporous silica particles have characteristics of excellent chemical stability, large specific surface area and convenient surface modification, showing promising application in drug carriers. However, their lack of bioactivity and slow biodegradation rate limit this application. To overcome these shortcomings, creating suitable biomaterials for drug carriers has become an indispensable and, therefore, important research direction in materials science. Compared with pure silica or silicate glasses, borosilicate glasses with excellent bioactivity degrade faster, enabling them suitable and favorable for drug carriers. Here, we synthesized mesoporous borosilicate glass microspheres (MBGMs) and characterized their properties of loading and releasing an antitumor drug, doxorubicin hydrochloride (DOX), and releasing their own various ions triggered by degradation. The results showed that BMGMs had a DOX loading amount of about 25 mg/g. Introduction of boron improved chemical activity and degrading rate of MBGMs, resulting in more DOX released in acidic enviroment than alkaline condition, which displayed a certain acid-responsive drug releasing behavior. Meanwhile, MBGMs can release functional ions such as SiO₄^4-, BO₃^3- and Ca²⁺, and induce hydroxyapatite formation, indicating sustained ion releasing ability and excellent bioactivity. Altogether, MBGMs, as a novel kind of drug carrier, have a potential application in the field of pathological bone defect repairing.

Key words: drug carrier, borosilicate glass, acid sensibility, bioactive material