Fate of bone marrow-derived stromal cells after intraperitoneal infusion or implantation into femoral bone defects in the host animal.

The fate of intraperitoneally injected or implanted male rat bone marrow-derived stromal cells inside female sibling host animals was traced using Y-chromosome-sensitive PCR. When injected intraperitoneally, Y-chromosome-positive cells were found in all studied organs: heart muscle, lung, thymus, liver, spleen, kidney, skin, and femoral bone marrow with a few exceptions regardless of whether they had gone through osteogenic differentiation or not. In the implant experiments, expanded donor cells were seeded on poly(lactide-co-glycolide) scaffolds and grown under three different conditions (no additives, in osteogenic media for one or two weeks) prior to implantation into corticomedullar femoral defects.

Hydroxyapatite coating of cellulose sponge does not improve its osteogenic potency in rat bone.

Regenerated cellulose sponges were coated biomimetically with hydroxyapatite to increase their osteogenic properties. Induction of apatite precipitation was carried out with bioactive glass in simulated body fluid (SBF) for 24 h and the final coating was carried out in 1.5 x concentrated SBF for 14 days.

Intact surface of bioactive glass S53P4 is resistant to osteoclastic activity.

Bioactive glass reacts with body fluids and is gradually dissolved in tissues and in cell cultures. We investigated whether osteoclasts contribute to this process, by culturing newborn rat bone-marrow cells containing osteoclasts on polished bioactive glass plates (glass S53P4). The cultures were inspected at days 1-5 and stained for alkaline phosphatase (ALP) to demonstrate osteoblasts and for tartrate resistant acid phosphatase (TRAP) to visualize osteoclasts.

Long-term evaluation of porous poly(epsilon-caprolactone-co-L-lactide) as a bone-filling material.

Porous poly(epsilon-caprolactone-co-L-lactide) (P(CL-co-LA, wt % ca. 5/95) sponges were prepared, coated biomimetically with CaP/apatite, and implanted with noncoated control sponges into rat femur cortical defects and dorsal subcutaneous space. The implants were inspected histologically at 2, 4, and 33 weeks after the operation.