Objective To review the progress and clinical application of malleable bone paste/putty. MethodsRecent literature about malleable bone paste/putty was reviewed and analyzed. ResultsThe preparation and clinical application of malleable bone paste/putty have become increasingly mature. Many kinds of malleable bone paste/putty have been applied extensively and the good clinical results have been achieved in the treatment of the irregular bone defects. The materials and methods for preparing malleable bone paste/putty are different. Then they have different bone repair abilities. ConclusionMalleable bone paste/putty provides effective method to treat irregular bone defects. But the malleable bone paste/putty still has some shortage, so further researches should be carried out.
Objective To research the effect of porcine acellular dermal matrix in the reconstruction of abdominal wall defects in rabbits, and to investigate the appl ication feasibil ity of xeno-transplantation of acellular dermal matrix. Methods The porcine acellular dermal matrix was prepared from a health white pig. Twenty-six Japanese white rabbits (weighing 2.2-2.3 kg, female or male) were randomly assigned to 2 groups: the control group (n=6) and the experimental group (n=20). In the control group, the full-thickness abdominal wall defect of 5.0 cm × 0.5 cm was made, and the defect wassutured directly; in the experimental group, the full-thickness abdominal wall defect of 5.0 cm × 2.5 cm was made, and the defect was repaired with porcine acellular dermal matrix patch at the same size as the defect. At 5 weeks after surgery, the incidence of hernia and the intra-abdominal adhesions were observed and the wound breaking strength was compared between the patchfascia interface and the fascia-fascia interface. The graft vascularization was evaluated through histological analysis at 6 months after surgery in the experimental group. Results No hernia occurred in all rabbits of 2 groups. At 5 weeks after surgery, heal ing was observed between patch and the muscularfascia; the vascularization was seen in the porcine acellular dermal matrix patch. There was no significant difference in the adhesion grade (Z= —0.798, P=0.425) between the experimental group (grade 2 in 1 rabbit, grade 1 in 5, and grade 0 in 12) and the control group (grade 1 in 1 and grade 0 in 5). No significant difference was found (t= —0.410, P=0.683) in the breaking strength between the patch-fascia interface in the experimental group [(13.0 ± 5.5) N] and the fascia-fascia interface in control group [(13.6 ± 4.0) N]. In the experimental group, the small vessels and the infiltration of inflammatory cells were observed in the porcine acellular dermal matrix patch after 5 weeks through histological observations. The junctions of the patch-fascia interface healed with fibrous connective tissue. At 6 months after surgery, the inflammation was subsided and the collagen fiber of the patch was reconstructed. Conclusion The porcine acellular dermal matrix patchhas good results in repairing full-thickness abdominal wall defect. The patch-fascia interface has siml iar breaking strength to the fascia-fascia interface. The collagen fibers of the patch are reconstructed.
Objective To evaluate the cytotoxicity of microdosis peracetic acid (PAA) so as to provide the evidence for making residual l imit of PAA steril ization. Methods Mouse fibroblasts (L929 cell l ine) cultured in vitro were observed to evaluate the influence of microdosis PAA including 1 × 10-6, 2 × 10-6, 3 × 10-6, 4 × 10-6, 5 × 10-6, and 10 × 10-6 (V/V). Theproliferation of cells was determined by MTT assay at 2, 4, and 7 days of culture. The growth curve and the relative growth rate (RGR) were obtained. The cytotoxicity of PAA at different concentrations was evaluated according to RGR. Results At 2, 4, and 7 days after culture, fibroblasts of 1 × 10-6 group grew with normal morphology analogous to control group, while the cell growth of other groups were poor. With the increase of PAA concentration, the absorbance (A) values decreased, which suggested that there was a significant negative correlation between cell prol iferation and PAA concentration. And the correlation coefficient was — 1.000 at 2 and 4 days, — 0.964 at 7 days. There was no significant difference in A value between 1 × 10-6 group and the control group (P gt; 0.05), while there were significant differences in A value between the control group and other concentration groups (P lt; 0.05). The growth curve of 1 × 10-6 group was similar to that of the control group, both had obvious phase of exponential growth. The growth curves of other groups had no obvious phase of exponential growth. The cytotoxicity of 1 × 10-6 group was classified as level 1, 2 × 10-6 group as level 2, 3 × 10-6 group as level 3, 4 × 10-6 group as level 3-4, 5 × 10-6 group and 10 × 10-6 group as level 4. Conclusion PAA of 1 × 10-6 had no obvious cytotoxicity. The residual l imit of PAA less than 1 × 10-6 was recommended.
Objective To explore the feasibil ity of using PKH26 as a cell tracer to construct tissue engineered bone. Methods BMSCs isolated from the bone marrow of 1-week-old New Zealand white rabbit were cultured. The BMSCs at passage 3 were labeled with PKH26 and were observed under fluorescence microscope. The percentage of the labeled cells wasdetected by Flow cytometer. The labeled cells were induced to differentiate into osteoblasts in vitro and the morphology of the cells after induction was observed under inverted phase contrast microscope. The osteogenic induction was evaluated by ALP staining and Alizarin red staining. The cells labeled with PKH26 were seeded on the bio-derived bone to construct tissue engineered bone in vitro. Then the compound of cells and material were observed under fluorescence microscope. The compound of labeled cells and material were implanted into the rabbit thigh muscle, and the transformation of the labeled cells was observed by fluorescence microscope 14 and 28 days later. Results Fluorescence microscope observation: the BMSCs labeled by PKH26 were spherical and presented with red and uniform-distributed fluorescence, and the contour of the cells were clearly observed when they were adherent 24 hours after culture. Flow cytometric detection revealed that the percentage of labeled cells was 97.2%. After osteogenic induction, the morphology of the cells changed from long-fusiform to polygon-shape or cube-shape, more ECM was secreted, andthe ALP and the Alizarin red staining were positive. At 48 hours after culturing the PKH26 labeled BMSCs with bio-derived bone, the fluorescence microscope observation showed that there was red fluorescence on the surface and inside of the material. At 14 days after implantation, the labeled cells with red and l ight fluorescence were evident in the implantation area; while at 28 days, the cells with red fluorescence were still evident but less in quantity and weaker in fluorescence strength. Conclusion PKH26 can be used as BMSCs label for the construction of tissue engineered bone in vitro and the short-term tracing in vivo.