[Experimental study for repair of cranial defects with bone marrow stromal cells and modified alginate]

The primary aim of this investigation was to determine whether expanded BMSCs in vitro mixed with modified alginate gelatin could repair critical defects in rats without the addition of exogenous growth or bone morphogenetic factors.

Bone marrow stem cells from syngeneic rats cultured in vitro and mixed with modified alginate gel to paint the cranial critical size defect. A full-thickness cranial plate defect was created without damage of dura mater. Modified alginate gelatin with or without BMSCs were painted over the cranial defects. Animals being made cranial defect but received no implant served as sham-operated controls. Craniotomy defects were divided into three groups, which included defects left unpainted (group I, n=6), defects painted with modified alginate gelatin alone (group II, n=6), and defects painted with a modified alginate mixed with BMSCs (group III, n=6). A total of 18 implant experiments were carried out, with postsurgical radiographic and histological analysis completed at 12 week.

None of the implants exhibited extrusion or infection. Radiographs showed a likely increased calcification in group III, without finally new calcification in group I and in group II. Histology showed that group I and group II were featured by thinning of the bone at the edges of the defect margins with minimal bone growth inward and dense fibrous tissue with rudimentary alginate material spanning the intervenient gap. The results demonstrated that a great amount of new bone in growth took place in BMSCs-alginate group, stemming from cranial defect edges and proceeding inward.

Transplantation of syngeneic BMSCs with alginate gel can serve as an example of a cell-based treatment for skeletal reformation and would be especially useful for augmenting or regenerating bone in skeletal defects. So syngeneic BMSCs with alginate gel demonstrate a potential technique to regenerate a variety of skeletal defects that occur in different clinical scenaries.