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Objective: To review the application and research progress of transcutaneous oxygen pressure (TcPO 2 ) in scar assessment., Methods: The original articles about scar and TcPO 2 were reviewed and analyzed., Results: Hypoxia environment plays an important role in the progression of scar tissue. TcPO 2 can accurately reflect the oxygen tension of scar tissue, which is of great significance in the assessment of scar maturity, the guidance of scar treatment, and the study of correlations between hypoxia and the progression of scar., Conclusion: TcPO 2 measurement is important in the study of scar evaluation, treatment, and correlation between hypoxia and scar formation.

Objective: To investigate the effect of sagittal split ramus osteotomy(SSRO) combined with distraction osteogenesis(DO) for hemifacial microsomia (HFM)., Methods: From January 2013 to September 2015,7 cases of unilateral HFM were included in the study. The 3-dimensional reconstruction images were used for the operation design. The location of the germs and inferior alveolar nerve was marked to avoid injury. The distractor was fixed after SSRO. The distractor was distracted 2-4 mm intraoperatively and began enlongation 3-5 days after operation,1-2 mm every day until the pre-designed length attained. The patients were followed up for 3-D CT and measurement of the height of bilateral ramus., Results: The enlongation length was 7 mm to 20 mm(mean,14.6 mm).The facial symmetry and occlusion plane was improved a lot. No complication occurred. The mean follow-up period was 22 months (range 17-32 months) with almost symmetrical appearance and occlusion function., Conclusions: SSRO combined with DO has a good therapeutic effect and low complication for patients with HFM. The distraction rate is relatively high with a short treatment period. The ramus width, even thickness, are not decreased, or even can be increased after DO.

Objective: To compare the tissue engineered cartilage constructed with chondrocytes derived from auricular and articular cartilage., Methods: Chondrocytes were isolated from porcine auricular and articular cartilage, and BMSCs were obtained from bone marrow aspirate and cultured. Each kind of chondrocytes were resuspended alone or mixed with BMSCs at a ratio of 1:1, and seeded onto PGA/PLA scaffolds to construct tissue engineered cartilage (n = 4). The constructs were cultured for 8 weeks in vitro and then subcutaneously implanted into nude mice for 6 weeks. The differences between chondrocytes monoculture from articular and auricular cartilage or between each of them co-cultured with BMSCs were evaluated by gross view, measurement of thickness and wet weight, histological examinations including H&E, Safranin O, type II collagen, and Ponceau's & Victoria blue staining, and gene expression analysis of cartilage related genes., Results: No obvious differences were found histologically among the complexes constructed in vitro 8 weeks except for few elastic fibers secreted in the auricular chondrocytes + BMSCs co-culture group. Neo-cartilage is thicker in the groups of articular chondrocytes (38. 1% than the group of auricular chondrocytes, P < 0.05) and articular chondrocytes + BMSCs co-culture (19.3% than the group of auricular chondrocytes + BMSCs, P < 0.05). However, after 6 weeks in vivo the elastic fibers were found positive in the complexes constructed by auricular chondrocytes, and its staining was even stronger and more homogenous in the group of auricular chondrocytes + BMSCs co-culture. The tissues generated by articular chondrocytes alone and co-cultured with BMSCs both formed the characteristic features of three-layer structure of hyaline cartilage and ossified in vivo with significant up-regulation of COL10A1 and MMP-13. To summarize, auricular chondrocytes formed the elastic cartilage while articular chondrocytes formed the hyaline cartilage during the development of tissue engineered cartilage either by monoculture or the co-culture with BMSCs., Conclusions: The chondrogenic response of chondrocytes from different cartilage origins demonstrates that an initial chondrocyte and cartilage type recapitulates the same in later tissue-engineered development.

Objective: To review the research progress of the current methods of inducing bone marrow mesenchymal stem cells (BMSCs) to chondrogenic differentiation in vitro so as to provide references for researches in cartilage tissue engineering., Methods: Various methods of inducing BMSCs differentiation into the chondrogenic lineage in vitro in recent years were extensively reviewed and analyzed., Results: Adding exogenous growth factors is still the mainly method of inducing BMSCs differentiation into the chondrogenic lineage; among the members, transforming growth factor beta (TGF-beta) family is recognized as the most important chondrogenic induction factor. Other important inducing factors include various chemical factors, physical factors, transgenic methods, and the microenvironmental induction. But the problems of low inducing efficiency and unstable inducing effects still exist., Conclusion: The progress of chondrogenic induction of BMSCs promotes its utilization in cartilage tissue engineering. Further researches are needed for establishing more efficient, simpler, and safer inducing methods.

Objective: To study the feasibility of human adipose derived stem cells (ADSCs) in monolayer culture induced into smooth muscle cells in vitro as seeding cells in vascular tissue engineering., Methods: The mononuclear cells in human adipose were separated by collagenase treatment and seeded on culture dishes with the density of 5 x 10(5)/cm2. Cells were cultured in M-199 plus 10% FBS. When reaching confluence, the cells were subcultured by 0.1% trypsin and 0.02% EDTA treatment, PDGF-BB (50 ng/mL) and TGF-beta1 (5 ng/mL) were added at the passage 1 to enhance the smooth muscle cells' phenotype. Cells were cultured under the inducing medium for 14 days. The morphology of induced cells was observed under the microscope. Cellular immunofluorescence and RT-PCR were used to determine the expression of smooth muscle cell markers of the post-induced cells. Flow cytometry (FACs) was used to examine the positive rate of induced team., Results: Cocultured in M-199 media including TGF-beta1 and PDGF-BB, the proliferating capability of the induced cells was significantly downregulated compared with the uninduced cells (P < 0.01). The induced cells exhibited "Hill and Valley" morphology, while the uninduced cells were similar to ADSCs of P0 which had the fibroblast-like morphology. The results of immunofluorescence indicated that the induced cells expressed smoothmuscle (SM) cell-specific markers including a-smooth muscle actin (alpha-SMA), SM-myosin heavy chain (SM-MHC) and Calponin. The results of RT-PCR revealed that the induced cells also expressed alpha-SMA, SM-MHC, Calponin and SM-22alpha. The positive rates of alpha-SMA, SM-MHC and Calponin in FACs were 3.26% +/- 1.31%, 3.55% +/- 1.6% and 4.02% +/- 1.81%, respectively, before the cells were induced. However, 14 days after the cell induction, the positive rates were 48.13% +/- 8.31%, 45.33% +/- 10.68% and 39.13% +/- 9.42%, respectively. The positive rates in induced cells were remarkably higher than those in uninduced cells (P < 0.01)., Conclusion: The human ADSCs can be induced to express vascular smooth muscle markers, and they are a new potential source of vascular tissue engineering.

In order to prepare three-dimensional scaffolds with "ideal pore-structure" for tissue engineering, a novel water dissoluble adhesive was developed, and the property of adhesive as well as influence of experimental condition on bonded porogen assembly was investigated. Experimental results showed that it was possible to fabricate large dimensional porogen assembly with homogenous and controllable bonding extent by this adhesive, and a large dimensional (45 mm in diameter, 55mm in thickness) biodegradable poly(D,L-lactic acid)(PDLLA) scaffold resulting from bonded porogen was formed. The scaffolds with high porosity as well as with controllable and homogeneous inner-structure can be easily formed. In addition, pore size of scaffolds as well as diameter of openings can be controlled by adjusting the porogen size and bonding degree in bonded porogen assembly.

The recombinant human Smad7 adenoviral vector was constructed by direct DNA cloning protocol and then transfected into 293 cells for virus packaging. After amplification and purification, the recombinant adenovirus was used to infect the keloid fibroblasts. The Smad7 mRNA transcription of the infected cells was detected by RT-PCR. The recombinant Adeno-Smad7 was correctly constructed and confirmed by both restriction analysis and PCR analysis. RT-PCR showed the over expression of adenovirus mediated Smad7 mRNA in keloid cells. These results demonstrated that the recombinant Smad7 adenoviral vector can be expressed in cultured cells in vitro, and it may provide a new therapeutic strategy for keloid gene therapy.

Objective: To investigate the effect of tissue engineered tendon using autologous dermal fibroblasts in repairing tendon damage., Methods: Skin tissues were resected from abdomen of 5 pigs. Fibroblasts were isolated from the skin pieces and cultured in vitro. Bundles of polyglycolic acid (PGA) were arranged in parallel and mixed with the suspension of fibroblasts to form a cell-scaffolded construct, which was further cultured in vitro for 1 week. The tendon of musculus flexor digitorum superficialis of pig's right leg was cut with a defect 3 cm long and then bridged with the cultured construct. Six weeks later, specimens of the regenerated tendon of right musculus flexor digitorum superficialis and specimens of corresponding left leg were taken for gross examination, microscopy and biomechanical analysis., Results: After implantation of the fibroblast-biomaterial complex the wounds healed up and the pigs moved well. The histology of the implanted tendon was similar to that of natural tendon. The breaking strength and maximum tensile force were 173.0 +/- 18.2 N and 18.9 +/- 1.9 MPa, reaching 57.4% and 51.9% of those of normal tendon respectively., Conclusion: Skin fibroblasts can be used as seed cells to regenerate tendon with normal structure and function.

Objective: To repair critical-sized meniscal defects in an immunocompetent mammal by tissue engineering approach., Methods: 15 45-day-old Changfeng crossbred pigs were selected as experimental animals. Autologous fibrochondrocytes were obtained from left knee menisci by modified Klagsbrun's method and were proliferated in vitro to a proper amount. A 1-cm-long full-layer defect of right medial meniscus was created anterior to the medial collateral ligament. PGA-fibrochondrocyte-Pluronic complex, fibrochondrocyte-Pluronic complex or PGA only was respectively implanted into the defects. We used intact menisci and untreated meniscal defects as controls. Samples respectively obtained in 9 w, 16 w and 25 w were appraised by general observation, histology, biochemistry and biomechanics., Results: From the sights of general morphology, histological structure and Young's Modulus (59.7% of that in normal meniscus at 25 w), the PGA-cell-Pluronic complex can form the best quality tissue, which can stabilize the GAG ratio (74.5% of that in normal cartilage at 25 w) of femoral entocondyle cartilage., Conclusion: Autologous tissue-engineered fibrocartilage is a promising feasible method to regenerate or reconstruct menisci so as to hold back the degenerative changes of the knee.

Objective: To investigate the feasibility of chondrogenic phenotype differentiation of adult swine bone marrow stem cells(MSCs) in a defined medium as seeding cells in cartilage tissue engineering., Methods: A volume of 5 ml bone marrow was aspirated from swine iliac crest and cultured in the complete medium of DMEM-LG for two weeks. The growth and ultrastructure of the cultured MSCs were observed. Immunohistochemistry and in situ hybridization were applied to detect the expression of collagen type II., Results: The MSCs changed from a spindle-like fibroblastic appearance to a polygonal shape when transferred from the complete medium of DMEM-LG to a defined medium. A large amount of endoplasmic reticulum was observed in large Golgi ccmplex and mitochondria. The differentiation of MSCs toward chondrogenic phenotype was verified by the positive result of collagen type II through immunohistochemistry and in situ hybridization respectively., Conclusions: Bone marrow stem cells obtained from adult swine can differentiate to be chondrogenic phenotype when cultured in vitro. MSCs can likely be served as optimal autogenous cell source for cartilage tissue engineering.

Objective: To explore a feasible method to repair full-thickness skin defects with tissue engineered techniques., Methods: The skin specimens were cut from the Changfeng hybrid swines' abdomen, then keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA and type II collagenase. The cells were seeded in petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with dispase II (keratinocytes) or trypsin (fibroblasts) to separate them from the floor of the tissue culture dishes. A biodegradable material-pluronic F-127 was prefabricated and mixed with these cells, and then the cells-pluronic compounds were seeded evenly into polyglycolic acid (PGA). Tinally the constructs were replanted to autologous animals to repair full-thickness skin defects. Histological changes were observed in 1, 2, 4 and 8 weeks postsurgery., Results: The cells-pluronic F-127-PGA compounds could repair autologous full-thickness skin defects. Histologically, the tissue engineered skin was similar to normal skin with stratified epidermis overlying a moderately thick collageneous dermis., Conclusion: Tissue engineered skin can repair autologous full-thickness skin defects with primary-cultured keratinocytes and fibroblasts as seed cells and PGA as a cell carrier.