Preparation and properties of calcium phosphate cements incorporated gelatin microspheres and calcium sulfate dihydrate as controlled local drug delivery system
To develop high macroporous and degradable bone cements which can be used as the substitute of bone repairing and drug carriers, cross-linked gelatin microspheres (GMs) and calcium sulfate dihydrate (CSD) powder were incorporated into calcium phosphate bone cement (CPC) to induce macropores, adjust drug release and control setting time of α-TCP–liquid mixtures after degradation of GMs and dissolution of CSD. In this study, CSD was introduced into CPC/10GMs composites to offset the prolonged setting time caused by the incorporation of GMs, and gentamicin sulphate (GS) was chosen as the model drug entrapped within the GMs. The effects of CSD amount on the cement properties, drug release ability and final macroporosity after GMs degradation were studied in comparison with CPC/GMs cements. The resulting cements presented reduced setting time and increased compressive strength as the content of CSD below 5 wt%. Sustained release of GS was obtained on at least 21 days, and release rates were found to be chiefly controlled by the GMs degradation rate. After 4 weeks of degradation study, the resulting composite cements appeared macroporous, degradable and suitable compressive strength, suggesting that they have potential as controlled local drug delivery system and for cancellous bone applications.
KeywordsCompressive Strength Setting Time Hydration Product Composite Cement Calcium Phosphate Cement
The authors appreciate financial support from the Natural Science Foundation of China (Grant No. 50772072, 51072129, 30872639) and the Tianjin Natural Science Foundation (Grant No. 11JCYBJC02600).
- 1.LeGeros R, Chohayeb A, Shulman A. Apatitic calcium phosphates: possible dental restorative materials. J Dent Res. 1982;61:343–8.Google Scholar
- 2.Brown W, Chow L. A new calcium phosphate setting cement. J Dent Res. 1983;62:672–8.Google Scholar
- 22.Zai YJ, Cai S, Zhou W, Li XD. Mechanical behavior of calcium phosphate based cement/gelatin microspheres composite scaffolds. J Chin Ceram Soc. 2010;38(8):1568–72.Google Scholar
- 23.Cai S, Yao KD, Guan YH. Effects of hydroxyapatite seeds on the hydration of α-calcium phosphate cement. J Chin Ceram Soc. 2003;31(1):108–12.Google Scholar