554 Characterizing robocasting and freeze casting HA/TCP scaffolds in bone regeneration

Thursday, March 22, 2012: 3:30 p.m. - 4:45 p.m.
Presentation Type: Poster Session
M. FINZEN1, W. YU2, Q. FU3, S.J. MARSHALL4, G.W. MARSHALL1, A. TOMSIA1, and J. LEE5, 1University of California - San Francisco, San Francisco, CA, 2Dept. of Oral & Maxillofacial Surgery, University of California - San Francisco, San Francisco, CA, 3Materials Science, Lawrence Berkeley National Labratory, Berkeley, CA, 4Preventive and Restorative Dent Sci, University of California - San Francisco, San Francisco, CA, 5Dept. Oral and Maxillofacial Surgery, University of California - San Francisco, San Francisco, CA
Objective:

Biphasic calcium phosphate bioceramics consisting of hydroxylapatite (HA) and tricalcium phosphate (TCP) have received considerable attention as bone graft substitutes because of their excellent osteoconductivity comparing to other materials. Freeze casting and robocasting are very appealing candidate technologies for building ceramic scaffolds. However, the biocompatibility of HA/TCP scaffolds has not been extensively evaluated.

Method:

The scaffolds (5X5X3mm) made of HA/TCP (composition 60:40) by either robocasting or freeze casting were tested. Human bone marrow stromal cells (hBMSCs) were used to investigate the biocompatibility of these scaffolds. Cell attachment were examined using scanning electronic microscope (SEM) after cell seeding at 1, 4, 7 days. Proliferation of hBMSCs on the scaffolds was determined by MTT assays at day 1, 4, 7, and 10. Osteoinductivity ability was analyzed by culturing hBMSCs on the scaffolds in osteogenic induction medium in vitro. 

Result:

hBMSCs  attached on both scaffolds after day 1 and exhibited no difference. During early culture, from day 1 to day 4, no difference of proliferation rate was detected between freeze casting and robocasting scaffolds. After Day 7, hBMSCs proliferation rate slightly decreased on freeze casting. However, after cultured in induction medium, both osteocalcin and Runx2 expression were higher on freeze casting than robocasting by day 7. 

Conclusion:

Both robocasting and freeze casting HA/TCP scaffolds are biocompatible for hBMSCs attachment, proliferation, and differentiation. However, the specific parameters, such as porosity of the scaffolds and cell seeding procedures need to be optimized for future clinical applications.

This abstract is based on research that was funded entirely or partially by an outside source: NIH/BRP Grant #R01 DE015633, AAOMS Foundation Award

Keywords: Bone repair, Cell culture, Oral surgery, Scaffolds and Tissue engineering