Sequential transplantation of exosomes and BMSCs pretreated with hypoxia efficiently facilitates perforator skin flap survival area in rats.

Bone marrow mesenchymal stem cells (BMSC) are promising candidates for the treatment of trans-territory perforator flap necrosis. However, the low retention and survival rate of engrafted BMSCs limit their therapeutic efficacy. Strategies either modifying BMSCs or alleviating the inflammatory environment may solve this problem. Thus, we aimed to explore the therapeutic efficacy of sequential transplantation of exosomes and hypoxia pretreated BMSCs on flap necrosis. After the perforator flap model was created, the exosomes derived from BMSCs were injected immediately into choke zone II followed by transplantation of hypoxia pretreated BMSCs on Day 2. Gross view was performed to assess the flap survival, enzyme-linked immunosorbent assay was performed to evaluate the inflammatory factor level, microvessel number was assessed and quantitative polymerase chain reaction (qPCR) was performed to assess angiogenesis. We found that exosome delivery significantly reduced inflammatory cytokines levels on Day 1 and Day 3 and promoted the engrafted BMSCs' survival on Day 7. After combining with transplantation of hypoxia pretreated BMSCs, the flap survival rate and the angiogenesis-related gene expression were significantly higher than in the other three groups; the von Willebrand factor (vWF) vascular diameter and vWF vascular count were significantly higher than in the phosphate buffered saline (PBS) group. Thus, we concluded that sequential transplantation of exosomes and BMSCs combinatorially pretreated with hypoxia further facilitated flap survival. This sequential transplantation approach provides novel insights into the clinical treatment of flap necrosis.

Reconstruction of Lagophthalmos of Upper Eyelid With a Subcutaneous Pedicled Propeller Flap.

ABSTRACT: An 11-year-old boy presented with lagophthalmos of the left upper eyelid after traumatic scar contracture. Chronic eyelid hypophasis could produce dryness, foreign body sensation, cornea exposure. To reconstruct the upper eyelid defects after scar release represented a significant challenge in terms of recreating functional eyelids. The authors applied the orbital subcutaneous pedicled propeller flap for one-stage reconstruction of the lagophthalmos. Four weeks after surgery, the patient had functional eyelid with no ectropion, cornea exposure or conjunctivitis and the appearance of eyelid was improved. And the final result was found to be acceptable at 6 months follow-up. The authors consider that to repair the lagophthalmos of upper eyelid, the use of orbital subcutaneous propeller flap can achieve both functional and appearance improvement, it is an effective method with flexibility and personalization.

Co-Culture of Adipose-Derived Stem Cells and Chondrocytes With Transforming Growth Factor-Beta 3 Promotes Chondrogenic Differentiation.

Tissue engineering cartilage is a promising strategy to reconstruct the craniofacial cartilaginous defects. It demands plenty of chondrocytes to generate human-sized craniofacial frameworks. Partly replacement of chondrocytes by adipose-derived stem cells (ADSCs) can be an alternative strategy.The study aimed at evaluating the chondrogenic outcome of ADSCs and chondrocytes in direct co-culture with transforming growth factor-beta (TGF-ß3). Porcine ADSCs and chondrocytes were obtained from abdominal wall and external ears. Four groups: ADSCs or chondrocytes monocultured in medium added with TGF-ß3; ADSCs and ACs co-cultured with or without TGF-ß3. Cell growth rate was performed to evaluate the cell proliferation. Morphological, histologic and real-time polymerase chain reaction analysis were performed to characterize the chondrogenic outcome of pellets. ADSCs had favorable multi-lineage differentiation potential. Further, when ADSCs were co-cultured with chondrocytes in medium added with TGF-ß3, the cell proliferation was promoted and the chondrogenic differentiation of ADSCs was enhanced. We demonstrate that pellet co-culture of ADSCs and chondrocyte with TGF-ß3 could construct high quantity cartilages. It suggests that this strategy might be useful in future cartilage repair.

Forty-five cases of chest keloids treated with subcutaneous super-tension-reduction suture combined with postoperative electron-beam irradiation.

BACKGROUND: Chest keloids are challenging to surgeons because of their high recurrence rate. OBJECTIVE: To investigate the effectiveness of the subcutaneous super-tension-reduction suture technique with postoperative electron-beam irradiation in the treatment of chest keloids. MATERIALS AND METHODS: Forty-five patients with chest keloids underwent excision. To minimize the wound-closing tension, subcutaneous super-tension-reduction suture was used. The maximum tension reduction was placed on both dermis and subcutaneous tissue, which were far away from the incision. The consequence of such suturing was that the wound edges were moved centrally to elevate them like a bump after tying the buried knot. All patients received fractionated electron-beam radiation therapy starting within 24 hours after surgery, in a 5-Gy dose daily for 3 to 4 consecutive days, to a total dose of 15 to 20 Gy. RESULTS: The wounds healed primarily in all 45 cases. The bump at the incision began to flatten out after 2 to 3 months and was almost completely flat by 12 months postoperatively. Only 1 case of relapse (2.2%) was observed within 2 years of follow-up examination. CONCLUSION: The use of subcutaneous super-tension-reduction suture after chest keloids excision can greatly decrease tension on the dermis and the subcutaneous tissue and can, in combination with postoperative electron-beam irradiation, decrease the rate of relapse.

[The application of comparative proteomic analysis to screen proteins associated with mechanical properties of engineered cartilage: a preliminary study].

OBJECTIVE: To study proteins correlated with the mechanical properties of engineered cartilage by screening significantly changed proteins during cartilage formation by comparative proteomic analysis. METHODS: Human chondrocyte, cultured and expanded, were seeded onto a polyglycolic acid/polylactic acid (PGA/PLA) scaffolds. After 4 weeks of culture in vitro, the constructs were divided into three groups. There were 6 specimens in each group. For the regular in vitro culture group (A), the constructs were kept in culture at the original condition for an additional 6 weeks. For in vivo groups, the constructs were implanted subcutaneously into nude mice for either 6 weeks (B) or 12 weeks (C). All specimens were harvested for gross observation, average wet weight and volume measurement, histology, immunohistochemistry and biomechanics to evaluate the results. Meanwhile, comparative proteomic analysis was performed for each group, and those proteins involved in extracellular matrix with at least 2 folds up-regulation were chosen for further exploration. The correlations between Young's modulus and the relative content of the selected proteins were analyzed by Pearson correlation coefficient. RESULTS: All these samples in the three groups eventually formed hyaline-like cartilage structure. Specimens in C and B groups were similar with adult articular cartilage in appearance, and had multiple mature lacuna in histology. However, those specimens in A group had loose texture with irregular hypertrophy lacuna. Specimens implanted for 12 weeks in vivo had better wet weight (372.5 +/- 35.4) mg and Young's modulus (8.68 +/- 2.65) MPa than those cultured in vivo for 6 weeks (346 +/- 34.5) mg, (3.25 +/- 1.24) MPa (P < 0.01). In group A, they were (184.4 +/- 12.28) mg and (0.7 +/- 0.23) MPa. This study had detected 44 proteins in ECM by comparative proteomic analysis, then chosing the greatest ratio of 6 up-regulation proteins compared between C and A groups. The correlation results indicated the content of Decorin, Chondroadherin and Fibromodulin were linear correlation with the mechanical properties of engineered cartilage (P < 0.05). CONCLUSIONS: Comparative proteomic analysis could provide large scale information of associated proteins, making it profit for advanced research on the relationship between extracellular matrix and mechanical properties of engineered cartilage by combination with tissue reconstruction techniques.