ASGSB 1998 Annual Meeting Abstracts

[43]
EMBRYONIC LIMBBUD CELLS GROWN IN A BIOREACTOR PRODUCE CARTILAGE SUITABLE FOR BONE REPAIR.    H.C. Nguyen, D. Montufar-Solis, and P.J. Duke. Orthodontics and Dentofacial Orthopedics, UTHSC Dental Branch, Houston, TX, 77225.

A serious problem encountered by the orthopedic or oral surgeon is the procurement of materials to provide support and induce bone during repair of bony defects. Because many bones form by bone replacement of a cartilage model, i.e. endochondral ossification, cartilage can be used to repair bone. But the use of cartilage has been limited, in part by the amount of tissue available from conventional culture systems. A new method of growing cartilage uses a rotating bioreactor system developed by NASA, which provides homogenous distribution of nutrients, waste, and gases, and little accompanying turbulence or shear force. In previous studies, aggregates of mouse embryonic limb cells cultured in a Rotating Wall Vessel, when implanted subcutaneously, were found to hypertrophy, calcify, vascularize, and recruit additional cells. The actual stage of differentiation at time of implantation, however, was not assessed and the capability of the bioreactor to support cartilage differentiation from undifferentiated cells was not clear. In the present study, aggregates of embryonic limbbud cells to be used in repair of a skull defect were cultured in the bioreactor for three weeks. Some aggregates were fixed for histological studies and the remaining aggregates were implanted into a 2mm defect created in the skulls of C57 black mice. Control mice had defects, but no implant. Sections of nodules showed extensive cartilage differentiation and hypertrophy at time of implantation. Healing in the defects showed vascularization and mineralization in the wound site, but analyses of undecalcified and decalcified sections are still in progress.

This study demonstrates that the NASA bioreactor supports differentiation of cartilage from undifferentiated limbbud cells and that such cartilage is suitable for healing of defects in bone.

Supported in part by NIH/NIDR Training Grant T35 DE07252.

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