Objective To review the recent advances in transforming growth factor-β(TGF-β) super family study and its role in new bone formation. Methods The latest original articles related to this subject were retrieved extensively,especially the effect of TGF-β, bone morphogenetic proteins(BMPs) and activin(ACT) on distractionosteogenesis. Results TGF-β, BMPs and ACT play important roles in prompting new bone formation and each of them has different effects. Among them, TGF-β can stimulate the proliferation of osteoblast and synthesis ofextra cellular medium; BMPs can initiate the differentiation of interstitial cell toosteocyte; then ACT displays the combine effect of above two factors. Conclusion TGF-β superfamily can regulate new bone formation and thus shorten the course of mandibular distraction osteogenesis.
ObjectiveTo investigate the long-term effectiveness of microgenia treatment with natural coral, and the volume relationship between the implant and the new bone. MethodsA retrospective analysis was made on the cl inical data of 12 patients with microgenia treated by horizontal genioplasty with natural coral implantation between October 1998 and September 2004. There were 7 males and 5 females with the average age of 18.5 years (range, 15-28 years). The cephalometric data on the photo and X-ray films were collected at pre-operation, immediate after operation, and last follow-up. The vertical distance between lower lip point and inferior mental point, the vertical distance between inferior alveolar point and inferior mental point, the vertical distance of the osteotomic gap, and the distance between pogonion and the line between nasion and inferior alveolar point were measured, and the recurrence rates were caculated. ResultsAll incisions healed by first intention, and no complication occurred. All patients were followed up 8-12 years (mean, 9.2 years). X-ray films showed that the natural coral was replaced by new bone formation in the mental osteotomic gap; the new bone had good strength and firmly attached to the mentalis and periosteum. At last follow-up, the vertical distance between lower lip point and inferior mental point, the vertical distance between inferior alveolar point and inferior mental point, and the vertical distance of the osteotomic gap were decreased when compared with the ones at immediate after operation, and the mean recurrence rates were 6.1%, 22.9%, and 31.7%, respectively; and no obvious change was observed in the vertical distance between pogonion and the line between nasion and inferior alveolar point. Nine patients were satisfied with operation effectiveness; chin morphology was adjusted again in 3 patients. ConclusionNatural coral is a safe and effective bone substitute with enough stable new bone and good long-term effectiveness.
ObjectiveTo investigate the osteogenic differentiation potential and the biological features of synovium-derived mesenchymal stem cells (SMSCs) in vitro and to observe the osteogenic capability of the composite scaffolds constructed with SMSCs and hydroxylapatite/chitosan/poly L-latic acid (HA/CS/PLLA) in vivo. MethodSMSCs were separated and cultured with adherent method and enzymatic digestion method. Specific phenotypes of SMSCs were detected by flow cytometry after purification. Then, SMSCs were identified by oil red O staining, alkaline phosphatase (ALP) staining, and alizarin red staining after adipogenic and osteogenic induction, respectively. In vitro experiments:the expressions of osteogenic related genes[osteocalcin (OCN), collagen type I, ALP, and Runx-2] were detected by real-time fluorescent quantitative PCR at 1, 7, 14, 21, and 28 days after osteogenic induction; ALP activities were also determined by ELISA at 1, 3, 5, 7, 9, and 11 days after osteogenic induction; meanwhile, extracellular matrix calcium mineralization was detected by alizarin red S method at 7, 14, 21, and 28 days after osteogenic induction; the normal SMSCs were harvested as control group. In vivo experiments:Twenty-four Sprague Dawley (SD) rats were randomly divided into experimental group (n=12) and control group (n=12) . The 3rd passage SMSCs were seeded on HA/CS/PLLA to construct composite scaffolds, after adhesion for 72 hours in vitro, the composite scaffolds were implanted into the right thigh muscle of 12 SD rats as experimental group; HA/CS/PLLA was implanted into the right thigh muscle of the other 12 SD rats as control group. At 4 and 8 weeks after implantation, the scaffolds were harvested for X-ray film and histological examination to observe ectopic bone formation. ResultsThe positive rates of CD147, CD90, CD105, and CD44 were more than 95%, while the positive rates of CD117, CD34, CD14, and CD45 were less than 10%. Oil red O staining demonstrated red lipid droplets in the cytoplasm, and alizarin red staining showed flaky red calcifications, and cytoplasm was dyed brown by the ALP staining. The mRNA expressions of collagen type I, ALP, and Runx-2 were significantly increased at 7 days after osteogenic induction, and OCN mRNA expression was significantly increased at 14 days after osteogenic induction; ALP activity was significantly higher at 5, 7, 9, 11 days after osteogenic induction in the SMSC-induced group than control group and reached a maximum at 7 days (P<0.05) . Calcium mineralization was significantly enhanced at 14 days after osteogenic induction, and gradually increased with time (P<0.05) ; moreover, it was significantly higher in the SMSC-induced group than control group (P<0.05) . X-ray and histological examination demonstrated that the new bone tissues formed in 2 groups, but bone formation content of the experimental group was significantly more than that of the control group at 4 and 8 weeks after implantation (P<0.05) . ConclusionsSMSCs can be induced into osteoblasts both in vitro and in vivo, so SMSCs might be a promising seed cells for bone tissue engineering.