Bovine serum albumin release from novel chitosan-fluoro-aluminosilicate glass ionomer cement: Stability and cytotoxicity studies

Abstract 

Objective

This study aimed to evaluate the effect of adding chitosan (CS) to conventional glass ionomer cement (GIC) on protein release and its cytotoxicity.

Methods

Bovine serum albumin (BSA) was used as the released protein from two glass ionomer formulations. One (GIC+BSA) contained fluoro-aluminosilicate glass mixed with BSA, and another (GIC:CS+BSA) used a similar glass and BSA with 20% chitosan. Six disc specimens per group (10mm in diameter, 2mm in height) were prepared and placed in phosphate buffer saline, which was replaced at various times over 2 weeks. The released protein was determined by a BCA assay. Cytotoxicity of the extracts from these materials for 1, 2 and 7 days to dental pulp cells was evaluated using MTT assay.

Results

The GIC:CS+BSA released a burst of BSA in the first 6h, and slowly released at different rates over the 2 weeks. GIC+BSA showed a similar result, but protein could not be detected at the 12h. The protein release rate of GIC:CS+BSA was significantly greater than GIC+BSA (P<0.01); nearly three times higher. The released BSA had the same molecular weight as evaluated by SDS-PAGE. From the MTT assay, the percentages of viable cells were significantly different and can be arranged as: GIC:CS+BSA>GIC:CS>GI+BSA>GI and the cytotoxicity was increased by time of extraction.

Conclusion

Chitosan added in glass ionomer cement can prolong release of BSA as well as not increasing the toxicity to pulp cells. This material may be useful for protein delivery.

Keywords: Protein release, Albumin, Chitosan, Glass ionomer cement, Cytotoxicity, Pulp cells