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.

Continuous tension reduction technique in facial scar management: A comparison of W-plasty and straight-line closure on aesthetic effects in Asian patients.

W-plasty is a very popular scar excisional revision technique. The core of the technique is to break up the scar margins into small triangular components, so as to cause light scattering and make the scar less noticeable. However, due to skin tension, facial incision scars tend to spread. Applying W-plasty alone cannot achieve the ideal repair effect of facial scars. In this study, we proposed a scar revision technique combined W-plasty with continuous tension-reduction (CTR) technique to improve the appearance of facial scars. Sixty patients with facial scar were comprised in this retrospective study. Scars were assessed independently using the scar scale before and at 12-month follow-up. Clinical results showed a significant difference in scar appearance between different groups at 12-month follow-up. Vancouver scar scale (VSS), visual analogue scale (VAS) scores, and patient satisfaction were significant better in W-plasty and CTR than other groups at 12-month follow-up. No severe complications were reported. The application of the tension offloading device provides an environment where the tension is continuously reduced, which could greatly decrease tension on the surgical incision. Combined with W-plasty, this technique could significantly improve the scar's aesthetic appearance.

Subcutaneous Regeneration of Engineered Cartilage: A Comparison of Cell Sheets and Chondrocyte-Scaffold Constructs in a Porcine Model.

BACKGROUND: Stable cartilage regeneration in immunocompetent large animals remains a bottleneck problem that restricts clinical application. The inflammation elicited by degradation products of scaffolds has a decisive influence on cartilage formation. Although prolonged preculture in vitro could form mature engineered cartilage and allow sufficient degradation of scaffolds, the inflammatory reaction was still observed. This study explored the feasibility of using chondrocyte sheet technology to regenerate stable cartilage in the subcutaneous environment with a pig model. METHODS: Passage 1 chondrocytes were used to form cell sheets by high-density culture. As a control, chondrocytes were seeded onto polyglycolic acid/polylactic acid scaffolds for 6 and 12 weeks' in vitro preculture, respectively. Then, they were autologously implanted subcutaneously into pigs for 2, 8, and 24 weeks. Gross view, histologic staining, and biochemical and biomechanical characteristics were evaluated. RESULTS: With prolonged culture in vitro, relatively homogeneous engineered cartilages were formed with less scaffold residue. However, the chondrocyte-polyglycolic acid/polylactic acid group still encountered severe inflammation and inferior cartilage formation at 2 and 8 weeks in vivo. The engineered cartilage with cell sheet technique exhibited a relatively more stable and mature tissue structure without obvious inflammatory response at 24 weeks in vivo, which was similar to the native auricular cartilage. CONCLUSIONS: The chondrocyte sheet technique could successfully regenerate mature and stable engineered cartilages in pig models. It is possibly an effective method of repairing cartilage defects in the clinic that uses regenerated substitutes derived from autologous cell sheets.

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.

Continuous tension reduction to prevent keloid recurrence after surgical excision: Preliminary experience in Asian patients.

Surgical excision combined with postoperative radiotherapy is considered one of the most radical but most effective keloid therapeutic option. However, radiotherapy may not be appropriate for all keloid patients. In this study, we propose an alternate approach to prevent keloid recurrence and provide preliminary assessment in clinical efficacy of this treatment for keloids. Forty consecutive patients with different keloid sites underwent excision without postoperative radiation. After surgery, the tension offloading device was used at least 6 months for the purpose of continuous tension reduction at surgery incision. Scars were assessed independently using scar scale at before and 24-month follow-up. Overall, 38 patients completed this research. Clinical results showed that 35 patients achieved healing with an esthetic appearance at 24-month follow-up. Three patients showed relapse and the recurrence rate was 7.9%. Both of VSS (Vancouver Scar Scale) and JSW (Japan Scar Workshop Scar Scale) scores decreased significantly at 24-month follow-up visit than before. No severe complications were reported. Using the tension offloading device could greatly decrease tension on the surgical incision. The technique of continuous tension reduction could be used as an alternative method to prevent keloid recurrence under the condition of without radiotherapy.

Postoperative analgesia using dezocine alleviates depressive symptoms after colorectal cancer surgery: A randomized, controlled, double-blind trial.

BACKGROUND: Postoperative depression is one of the most common mental disorders in patients undergoing cancer surgery and it often delays postoperative recovery. We investigated whether dezocine, an analgesic with inhibitory effect on the serotonin and norepinephrine reuptake, could relieve postoperative depressive symptoms in patients undergoing colorectal cancer surgery. METHODS: This randomized, controlled, single-center, double-blind trial was performed in the Second Affiliated Hospital of the Army Medical University. A total of 120 patients were randomly assigned to receive either sufentanil (1.3 µg/kg) with dezocine (1 mg/kg) (dezocine group; n = 60) or only sufentanil (2.3 µg/kg) (control group; n = 60) for patient-controlled intravenous analgesia after colorectal cancer surgery. The primary outcome was the Beck Depression Inventory score at 2 days after surgery. The secondary outcomes included the Beck Anxiety Inventory, sleep quality, and quality of recovery scores. RESULTS: Compared with those in the control group, patients in the dezocine group had lower depression scores (7.3±3.4 vs. 9.9±3.5, mean difference 2.6, 95% CI: 1.4-3.9; P<0.001) at 2 days after surgery and better night sleep quality at the day of surgery (P = 0.010) and at 1 day after the surgery (P<0.001). No significant difference was found in other outcomes between the two groups. CONCLUSIONS: Intravenous analgesia using dezocine can relieve postoperative depression symptoms and improve sleep quality in patients undergoing colorectal cancer surgery.

Mechanical Loading Improves Engineered Tendon Formation with Muscle-Derived Cells: An In Vivo Analysis.

BACKGROUND: The authors' previous study showed that muscle-derived cells could regenerate strong engineered tendon with better tissue structure. However, little was known about the mechanism of neotendon built by muscle-derived cells, and the development and maturation of the cells. The authors hypothesized that mechanical loading modulated this process. The aim of this study was to investigate whether mechanical loading could regulate muscle-derived cell-based engineered tendon formation and maturation. METHODS: Muscle-derived cells were isolated, expanded, and seeded onto polyglycolic acid fibers that formed a cell-scaffold complex. After in vitro culture for 2 weeks, half of them were implanted without loading and the other half were sutured to mouse fascia that could provide a natural dynamic loading. At 12 and 24 weeks after implantation, histologic examinations, ultrastructure, and biomechanical characteristics were evaluated. RESULTS: Gross observation results showed that under mechanical loading, neotendon tissue could be generated with muscle-derived cells and the tissue structure became more mature with the increase of culture time. Well-organized aligned collagen fibers and elongated morphologic cells were observed on histologic examination under mechanical loading. In contrast, the nonload group failed to form neotendon, but formed disorganized fibrous tissue with significantly worse mechanical properties and poor collagen fibril structure. CONCLUSIONS: This study demonstrates that mechanical loading is indispensable in tendon tissue engineering with muscle-derived cells. Although muscle-derived cells have a potential advantage in neotendon regeneration, stress deprivation resulted in a distinctly inferior maturity level of engineered tendon.

Bone Marrow Mesenchymal Stem Cell-Based Engineered Cartilage Ameliorates Polyglycolic Acid/Polylactic Acid Scaffold-Induced Inflammation Through M2 Polarization of Macrophages in a Pig Model.

UNLABELLED: : The regeneration of tissue-engineered cartilage in an immunocompetent environment usually fails due to severe inflammation induced by the scaffold and their degradation products. In the present study, we compared the tissue remodeling and the inflammatory responses of engineered cartilage constructed with bone marrow mesenchymal stem cells (BMSCs), chondrocytes, or both and scaffold group in pigs. The cartilage-forming capacity of the constructs in vitro and in vivo was evaluated by histological, biochemical, and biomechanical analyses, and the inflammatory response was investigated by quantitative analysis of foreign body giant cells and macrophages. Our data revealed that BMSC-based engineered cartilage suppressed in vivo inflammation through the alteration of macrophage phenotype, resulting in better tissue survival compared with those regenerated with chondrocytes alone or in combination with BMSCs. To further confirm the macrophage phenotype, an in vitro coculture system established by engineered cartilage and macrophages was studied using immunofluorescence, enzyme-linked immunosorbent assay, and gene expression analysis. The results demonstrated that BMSC-based engineered cartilage promoted M2 polarization of macrophages with anti-inflammatory phenotypes including the upregulation of CD206, increased IL-10 synthesis, decreased IL-1ß secretion, and alterations in gene expression indicative of M1 to M2 transition. It was suggested that BMSC-seeded constructs have the potential to ameliorate scaffold-induced inflammation and improve cartilaginous tissue regeneration through M2 polarization of macrophages. SIGNIFICANCE: Finding a strategy that can prevent scaffold-induced inflammation is of utmost importance for the regeneration of tissue-engineered cartilage in an immunocompetent environment. This study demonstrated that bone marrow mesenchymal stem cell (BMSC)-based engineered cartilage could suppress inflammation by increasing M2 polarization of macrophages, resulting in better tissue survival in a pig model. Additionally, the effect of BMSC-based cartilage on the phenotype conversion of macrophages was further studied through an in vitro coculture system. This study could provide further support for the regeneration of cartilage engineering in immunocompetent animal models and provide new insight into the interaction of tissue-engineered cartilage and macrophages.

Tissue Engineering of Tendons: A Comparison of Muscle-Derived Cells, Tenocytes, and Dermal Fibroblasts as Cell Sources.

BACKGROUND: The rapid development of tendon tissue-engineering technology may offer an alternative graft for reconstruction of severe tendon losses. One critical factor for tendon tissue engineering is the optimization of seed cells. Little is known about the optimal cell source for engineered tendons. The aim of this study was to compare mouse muscle-derived cells, dermal fibroblasts, and tenocytes and determine the optimal cell source for tendon tissue engineering. METHODS: Mouse muscle-derived cells, dermal fibroblasts, and tenocytes were isolated and cultured in vitro. At passage 1, cellular morphology, cell proliferation, and tenogenic marker expression were evaluated. After seeding on the polyglycolic acid scaffolds for 2 weeks in vitro and 12 weeks in vivo, histologic qualities, ultrastructure, and biomechanical characteristics were evaluated. RESULTS: Proliferation and cellular morphology were similar for dermal fibroblasts and tenocytes, whereas muscle-derived cells proliferated faster than the other two groups. With regard to the phenotype difference between them, muscle-derived cells and tenocytes shared the gene expression of SCX, TNMD, GDF-8, and Col-I, but with MyoD gene expression only in muscle-derived cells. In contrast to dermal fibroblast and tenocyte constructed tendons, neotendon with muscle-derived cells exhibited better aligned collagen fibers, more mature collagen fibril structure, and stronger mechanical properties, whereas no significant difference in the dermal fibroblast and tenocyte groups was observed. CONCLUSION: Although dermal fibroblasts are candidates for tendon tissue engineering because they are similar to tenocytes in proliferation and neotendon formation, muscle-derived cells appear to be the most suitable cells for further study and development of engineered tendon.

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.

[Micro-plasma radio frequency treatment for facial post-burn hyperpigmentation].

OBJECTIVE: To observe the clinical effect of micro-plasma radio frequency treatment of facial post-burn hyperpigmentation. METHODS: From June 2012 to August 2013, a total of 25 cases with facial post-burn hyperpigmentation were treated with micro-plasma treatment for 3-5 times. The roller tip was used with setting of 60-90 watts and 3-4 passes were performed in different directions. Treatments were repeated at an interval of 8 weeks. RESULTS: All patients tolerated the pain. After treatment, the facial hyperpigmentation improved. Complete recovery was achieved in 4 cases; significant improvement in 11 cases; moderate in 7 cases and no effect in 3 cases. No hyperpigmentation, depigmentation and scar formation was observed. CONCLUSION: Micro-plasma radio frequency treatment is an ideal treatment for post-burn hyperpigmentation with lower side effect.

[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.