In vitro studies of carboxymethyl cellulose / gelatin and calcium phosphate / calcium sulfate cement based composites for bone tissue engineering

Abstract

In this study, a calcium phosphate (CPCs) which composed of tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD) and calcium sulfate dihydrate (CSD)-based cement was introduced into carboxymethyl cellulose (CMC)gelatin(Gel)andcitricacid(CA)hydrogelforbonetissueengineering. Inhere, 2w/v% CMC was mixed with 20 wt% CA and 10 wt% Gel to obtain the liquid phase. After that, 76.65% of TTCP was mixed with 23.35% of DCPD. This mixture was blended with 20 % of CSD in the total powder phase. Combined liquid and powder phases were molded in a syringe and set at 50◦C for 72h. Morphology of the composites were examined by using Scanning Electron Microscopy (SEM). Physical characteristics of the composites were investigated with swelling, degradation and pH studies after incubation in PBS at 37◦C. Cell culture studies were performed with bone marrowderived mesenchymal stem cell (BMDMSCs). Cell viability was measured with Alamar Blueassay. Finally, invitrocelladhesionwasobservedagainbyusingSEM.Theresults indicatedthehomogenousstructureofP62.5andP65andmicroporesinallcomposites. According to swelling-degradation results, except for P70, all the composites had the same swelling-degradation trend. At the end of 72h, when powder ratio was increased, the swelling degree was decreased. The powder ratio and degradation were inversely proportional. pH study showed that, at the end of 72h it reached around 7 which is similar with the physiological value for all composites. Cellular viability was calculated and only significant decrease was observed for P65 between 1-3 and 14 days. Overall, composites were successfully produced and according to results they had a potential for bone tissue engineering in terms of their biocompatibility.|Keywords : CPCs, CMC, Calcium sulfate, Composite, Bone, Biocompatibility.