Methods: Cells were isolated from human dental pulps. After culture and expansion the cells were encapsulated into self-assembling peptide nano-fibre hydrogel. The cell-gel constructs were cultured for two weeks. β-glycerophosphate, dexamethasone and L-ascorbic acid were added into the culture medium for another two weeks. The cell-gel constructs were transplanted subcutaneously into nude mice. Plain gel constructs without human dental pulp cells were transplanted into the control sites. Four weeks after the surgeries, the transplants were harvested for antibody stainings and radiographic examinations. The percentages of radio-opaque areas were analysis with one sample t-test.
Results: At all control sites, the gel constructs were completely resorbed with no new tissue formation. Radiographic examination showed that the specimens harvested from experiment sites contained mineralised nodules. The mean percentage for radio-opaque area was 63.6% (N=2, P= 0.014). Microscopic examination showed that the gel constructs have been transformed into whole pieces of vascularised tissue containing nodular structures. Antibody stainings showed the expression of type I collagen, osteopontin, osteocalcin and osteonectin in the nodules. Apparently they resembled developing bone.
Conclusion: The results show that it is possible to produce small pieces, measured by millimeters, of mineralised tissue using human dental pulp cells and self-assembling peptide nano-fibre hydrogel. The feasibility of making larger pieces, measured by centimeters, is subjected to further investigation.