@misc{schnieders_the_effect_2011, 
author={Schnieders, J., Gbureck, U., Vorndran, E., Schossig, M., Kissel, T.},
title={The effect of porosity on drug release kinetics from vancomycin microsphere/calcium phosphate cement composites},
year={2011},
howpublished = {journal article},
doi = {https://doi.org/10.1002/jbm.b.31910},
abstract = {The influence of porosity on release profiles of antibiotics from calcium phosphate composites was investigated to optimize the duration of treatment. We hypothesized, that by the encapsulation of vancomycin-HCl into biodegradable microspheres prior admixing to calcium phosphate bone cement, the influence of porosity of the cement matrix on vancomycin release could be reduced. Encapsulation of vancomycin into a biodegradable poly(lactic co-glycolic acid) copolymer (PLGA) was performed by spray drying; drug-loaded microparticles were added to calcium phosphate cement (CPC) at different powder to liquid ratios (P/L), resulting in different porosities of the cement composites. The effect of differences in P/L ratio on drug release kinetics was compared for both the direct addition of vancomycin-HCl to the cement liquid and for cement composites modified with vancomycin-HCl-loaded microspheres. Scanning electron microscopy (SEM) was used to visualize surface and cross section morphology of the different composites. Brunauer, Emmett, and Teller-plots (BET) was used to determine the specific surface area and pore size distribution of these matrices. It could be clearly shown, that variations in P/L ratio influenced both the porosity of cement and vancomycin release profiles. Antibiotic activity during release study was successfully measured using an agar diffusion assay. However, vancomycin-HCl encapsulation into PLGA polymer microspheres decreased porosity influence of cement on drug release while maintaining antibiotic activity of the embedded substance.},
note = {Online available at: \url{https://doi.org/10.1002/jbm.b.31910} (DOI). Schnieders, J.; Gbureck, U.; Vorndran, E.; Schossig, M.; Kissel, T.: The effect of porosity on drug release kinetics from vancomycin microsphere/calcium phosphate cement composites. Journal of Biomedical Materials Research  B. 2011. vol. 99 B, no. 2, 391-398. DOI: 10.1002/jbm.b.31910}}