Effects of natural polymers for enhanced silica-based mesoporous drug carrier

Abstract

A nanocarrier consisting of quercetin-loaded mesoporous silica as core, chitosan as initial coating, and gelatin polymer as an exterior coating was developed based on the sol-gel method to be used as a pH-sensitive drug delivery system. The structure, chemical properties, surface area, and morphology of coated mesoporous silica containing quercetin were addressed by XRD, FTIR, and BET analyses. The drug loading and entrapment efficiency were measured at about 18% and 73%, respectively, indicating the high loading capacity of the drug into the porous carrier. Also, the drug release pattern was traced in two different phosphate saline buffer solutions (pH 5.6 and pH = 7.4). According to the results, a rapid release in the early hours was observed, which was significantly improved by a chitosan polymer coating. Here 43% of the drug was released after 24 h in acidic buffer, while only 27% of the drug was released after 24 h in a neutral medium. Also, the use of gelatin was led to a relatively controlled release pattern. Moreover, the amount of drug release from gelatin-coated nanocarrier in an acidic medium was decreased down to 34% and 69% after 24 and 48 h, confirming the pH-sensitive behavior. The kinetic study demonstrated that the quercetin release from silica-based carriers follows the Higuchi model. Toxicity studies also showed that the viability cell of MCF-7 cells after 24 and 48 h exposure to drug-free carriers was 95% and 92%, respectively, indicating low carrier toxicity. According to the findings, the developed nanocarrier manufactured can be considered as a suitable option for intelligent drug delivery.