Searching an Appropriate Human Tissue Engineering Bone: a Preclinical Study

Craniofacial bone defect may result from facial trauma, infection, tumor resection or congenital anomaly. Reconstruction of craniofacial bone defect to achieve functional recovery and cosmetic demand became a common problem and challenge to craniomaxillofacial surgeons. Traditionally, autogenous materials are the gold standard to induced bony regeneration. However, they have some disadvantages that limit their use such as donor site morbidity, variable degree of resorption and the limitation of graft source. The alternative to the use of autogenous graft is xenograft, allograft or bone substitute materials such as hydroxyapatite. Some materials such as porous or granule ceramic (calcium phosphate) act mainly as a passive scaffold for bone formation through the mechanism of osteoconduction. Deminerilized bone matrix provides both osteoconduction and osteoinduction effect for bone healing with advantage of high cost. Although these materials enhance bone regeneration either in animal or human study, constant outcome cannot be obtained from and long period of bone healing is necessary especially in large bone defect. A new concept for bone regeneration is tissue engineering approach which combines cell capable of osteogenic activity with an appropriate scaffold to stimulate bony regeneration. In order to enhance the effect of bone regeneration by traditional bone substitutes and to produce constant and stable results, we apply the concept of tissue engineering (cells, scaffolds and cytokines) for better bony growth. In the past few years, we have successfully utilize the bone marrow or fat tissue derived mesenchymal stem cell with autogenous fibrin glue or hydrogel as scaffold to regenerate facial bone defect in animal experiments. For further clinical application, we combine two different sources of human mesenchymal stem cell as cell sources with different forms of bone substitutes bone substitute materials such as as scaffolds mixing with osteoinductive medium to induce stem cell into osteoprogenitor cell to search an ideal model for tissue engineering bone. Besides, the enhancing effect of cell proliferation and mineralization in scaffold with the help of perfusion bioreactor can be further investigated for clinical use in the future. The aim of this study was to conduct a pre-clinical study and answer the following questions 1). if adding human autogenous platelet rich plasma (PRP) which enhances cell attachment to different form of the scaffold (mixture of HA/ TCP) and contains osteoinductive component has better effect of osteogenesis than those scaffold without PRP. 2). If different sources of human mesenchymal stem cell derived from bone marrow or fat tissue in different form of bone substitute can achieve similar effect of bony regeneration. 3). If combination of different source of human stem cell, different form of bone scaffold and perfusion bioreactor will result in faster and better bone regeneration than those without perfusion bioreactor culture. Human bone marrow mesenchymal stem cells (BMSC) were aspirated from the patient’s ilium who received autogenous ilium bone graft. Human adipose-derived stem cells (ASC) were harvested from liposuction aspirate during liposuction surgical procedure. The cells were expanded and induced into osteoprogenitor cell with osteogenic cell culture medium. The BMSC or ASC cells were mixed with different bone substitute scaffold such as granule calcium sulfate or block calcium sulfate as experimental groups. In the meantime, the human PRP was added on the scaffold. The different cell- graft constructs were placed into subcutaneous pocket of nude mices. The animals in each group were killed at 2 and 4 months postoperatively. The experimental bone was harvested and the grafted were evaluated at different bone regeneration stage by gross, histological, and CT examination. New bone formation was calculated by software OsiriX 3.1.6 to compare the results.

Project ID:PC10001-1412
External Project ID:NSC99-2314-B182A-100-MY3