Faculty and Research

Bone Regeneration from Human Adult Stem Cells

Dr. Miroslav Tolar

Regenerative dentistry is a new dental field comprising biomedical, translational and clinical research on the use of stem cells for regeneration of defective tissues in the oromaxillofacial region.

There are two categories of stem cells: embryonic and adult. Embryonic stem cells are derived from the inner mass cells of blastula. They possess a big potential for growth and differentiation into practically all kinds of specialized cells. However, numerous technical and ethical problems remain to be solved, and clinical use of embryonic stem cells is still beyond the horizon. Adult stem cells are a different story. They have been found in all tissues constituting their regenerative potential. They can be isolated from a patient, cultured in vitro and reintroduced therapeutically. Using autologous cells (the recipient is the donor) avoids an immune reaction.

Therapy using a tissue-engineered bone can be applied in several specialized fields of dentistry, including as implantology, maxillofacial surgery, periodontics and orthodontics. Cells are obtained by aspiration of bone marrow, which is less painful and quicker healing than the traditional surgical collection of autologous particulate bone.

Recently, we have been studying the properties of human adult mesenchymal stem cells (hMSC) isolated from bone marrow aspirates. These cells can effectively differentiate into osteoblasts. They can serve for rebuilding of bone defects in the oromaxillofacial region by bone regeneration. Augmentation of the alveolar ridge of maxilla and mandible, sinus lift, filling of large bone defects after surgical treatment of cancer or after injury and repair of inborn bone defects are several examples of their clinical use.

We have isolated and expanded hMSC from volunteers and differentiated them into osteoblasts in vitro. Our plans involve a study and design of conditions for more rapid growth of hMSC in culture and, in the near future, clinical applications involving bone regeneration in dentistry.

Previously, we have studied transdifferentiation of skeletal muscle satellite cells into osteoblasts.

Selected Reference

Ozeki N, Lim M, Yao CC, Tolar M, Kramer RH (2006) Alpha7 integrin expressing human fetal myogenic progenitors have stem cell-like properties and are capable of osteogenic differentiation.  Experimental Cell Research 312:4162-80.

Dr. Miroslav Tolar, mtolar@pacific.edu, 415.929.6555