Customization of Soft Tissue Expanders: Improving Safety, Accuracy, and Efficiency for Treatment of Large and Complicated Skin Lesions.

BACKGROUND: Soft tissue expansion is a common technique for restoring large skin defects. Fixed-type expanders may be inappropriate for the following reasons: (1) the shapes and sizes of the defects vary in different patients; and (2) the bulged base of the fixed-type expander does not fit the curve of the human body, which may induce complications such as concave deformities or nerve palsy from continuous mechanical compression. The customized expander adjusts better to the shape and the topography of the expansion site compared with the fixed-type expander. It improves expansion efficiency and reduces complications caused by compression. METHODS: Between 2016 and 2022, customized soft tissue expansion was performed in 38 patients with skin lesions, including giant congenital melanocytic nevi and postburn scars. This series of patients included patients with a specific donor site shape that is unsuitable for fixed-type expanders. An expander was customized according to the shape of the donor site and then implanted in the subcutaneous pocket. After the expander reached a sufficient volume, the expander was removed, and the extra expanded skin flap was transferred to resurface the skin lesion. In the follow-up, the outcome and the complications were recorded. RESULTS: All the customized expanders fit not only the dimension but also the topography of the donor site. During expansion, 2 patients experienced leakage of the expander, and 3 patients suffered a skin rupture. In the remaining 33 patients, the expansion was successfully completed, and the expanded flaps restored the skin lesions as designed. The color and texture of the skin flaps remained satisfactory after long-term follow-up. CONCLUSIONS: Unlike fixed-type expanders, our customized expanders make it possible for "accurate" expansion, irrespective of the dimension and topography of the donor area. Customization of the expander helps increase efficiency and reduce complications caused by undue compression.

Downregulation of miR-10a inhibits cutaneous squamous cell carcinoma cell proliferation, migration, and invasion by targeting Syndecan-1.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is a malignancy of epidermal keratinocytes which accounts for approximately one-third of skin cancer-related death yearly. In this study, we aim to investigate the mechanism of miR-10a in regulating cellular function of cSCC cells and its possible role in prognosis of cSCC. METHODS: The expression of miR-10a was detected by qRT-PCR. Target mRNA candidates were detected by bioinformatic analysis. Proliferative and migration capability of cSCC cell were examined by MTT assay, wound healing assay, and invasion assay, respectively. miR-10a expression was monitored in cSCC patients to elucidate the relationship between miR-10a expression and outcomes of cSCC. RESULTS: In our study, we found that expression of miR-10a was significantly down-regulated in cSCC cell in vitro and in vivo. Moreover, our results revealed that SDC-1 was a likely target of miR-10a in regulating biologic function of cSCC cell. Additionally, miR-10a expression level was inversely correlated with cSCC cell differentiation and tumor progression. CONCLUSION: These findings in this study indicate the importance of miR-10a in cSCC cell hallmarks and its use as a novel target for cSCC treatment.

The cleft palate candidate gene BAG6 supports FoxO1 acetylation to promote FasL-mediated apoptosis during palate fusion.

BACKGROUND: Cleft palate is a common craniofacial defect, which occurs when the palate fails to fuse during development. During fusion, the palatal shelves migrate towards the embryonic midline to form a seam. Apoptotic elimination of medial edge epithelium (MEE) cells along this seam is required for the completion of palate fusion. METHODS: Whole exome sequencing (WES) of six Chinese cleft palate families was applied to identify novel cleft palate-associated gene variants. Palatal fusion and immunofluorescence studies were performed in a murine palatal shelf organ culture model. Gene and protein expression were analyzed by qPCR and immunoblotting in murine MEE cells during seam formation in vivo. Mechanistic immunoprecipitation studies were performed in murine MEE cells in vitro. RESULTS: WES identified Bcl-2 associated anthanogene 6 (BAG6) as a novel cleft palate-associated gene. In murine MEE cells, we discovered upregulation of Bag6 and the transcription factor forkhead box protein O1 (FoxO1) during seam formation in vivo. Using a palatal shelf organ culture model, we demonstrate that nuclear-localized Bag6 enhances MEE cell apoptosis by promoting p300's acetylation of FoxO1, thereby promoting transcription of the pro-apoptotic Fas ligand (FasL). Subsequent gain- and loss-of-function studies in the organ culture model demonstrated that FasL is required for Bag6/acFoxO1-mediated activation of pro-apoptotic Bax/caspase-3 signaling, MEE apoptosis, and palate fusion. Palatal shelf contact was shown to enhance Bag6 nuclear localization and upregulate nuclear acFoxO1 in MEE cells. CONCLUSIONS: These findings demonstrate that nuclear-localized Bag6 and p300 co-operatively enhance FoxO1 acetylation to promote FasL-mediated MEE apoptosis during palate fusion.

Botulinum toxin type A relieves sternocleidomastoid muscle fibrosis in congenital muscular torticollis.

Congenital muscular torticollis (CMT) is a neck deformity that involves shortening of sternocleidomastoid muscle (SCM) characterized by muscle atrophy and interstitial fibrosis. To investigate wheatear Botulinum toxin type A (BTA) has anti-fibrotic effects in CMT, we established acquired muscular torticollis that mimetics CMT in rabbit by intra-SCM injection of anhydrous alcohol. The treatment groups received BTA (2.5units or 5units) injection into the fibrotic SCM. The shortening and thickening of SCM were recorded by B-mode ultrasound. Changes in Col1A1, Fn, α-SMA expression were determined by immunohistochemistry. In vitro studies, TGF-ß induced NIH3T3 fibroblasts were used to evaluate anti-fibrosis effect of BTA. Expression of the myofibroblast marker α-SMA and fibrosis markers Col1A1 and Fn were detected by Western blotting and quantitative RT-PCR. Our results showed that BTA injection attenuated shortening and thickening of fibrotic SCM. Elevated expression of Col1A1, Fn, α-SMA were confirmed in this fibrotic muscle model but reversed after BTA injection. Similar results observed in TGF-ß induced NIH3T3 fibroblasts in both mRNA and protein levels. In conclusion, our results suggested that BTA could be a promising agent against SCM fibrosis in CMT through regulating fibroblast and inhibiting myofibroblast differentiation.

Decreased expression of microRNA-20a promotes tumor progression and predicts poor prognosis of cutaneous squamous cell carcinoma.

BACKGROUND: MicroRNA-20a (miRNA-20a or miR-20a) plays a key role in tumorigenesis and progression. But the prognostic value of miR-20a in cutaneous squamous cell carcinoma (CSCC) remains unclear. The aim of this study was to identify the association of miR-20a and the prognosis of CSCC patients. METHODS: The miR-20a expression was detected using quantitative real-time polymerase chain reaction (qRT-PCR) in 152 CSCC tissues and matched adjacent normal tissues. Kaplan-Meier and Cox regression analysis were utilized to determine the association of miR-20a with overall survival as well as the prognosis of CSCC patients. RESULTS: The expression of miR-20a was lower in CSCC tissues compared with adjacent normal tissues (P=0.000). Moreover, the expression of miR-20a was closely correlated with TNM stage (P=0.013). Kaplan-Meier analysis showed that patients with low miR-20a expression had significantly poorer overall survival than those with high miR-20a expression (P<0.05). Multivariate analysis revealed that miR-20a expression (P=0.001, HR=3.262, 95% CI: 1.635-6.520) could influence the prognosis and might be an independent prognostic predictor in CSCC. CONCLUSIONS: Our results indicated that low miR-20a expression was associated with tumor stage of CSCC and suggested that miR-20a expression would be a novel biomarker for predicting clinical outcomes in CSCC patients. The inhibition of miR-20a might even become a new therapeutic method for the treatment of CSCC.

Bone regeneration in a rabbit ulna defect model: use of allogeneic adipose-derivedstem cells with low immunogenicity.

Tissue engineering provides new potential treatments for the repair of bone defects. Bone-marrow-derived mesenchymal stem cells (BMSCs) represent an attractive cell source for therapeutic applications involving tissue engineering, although disadvantages, such as pain of harvest and low proliferation efficiency, are major limitations to the application of BMSCs in the clinic. Adipose-derived stem cells (ASCs) with their multilineage potential and satisfactory proliferation potential can be induced into the osteogenic lineage in vitro and can be anchored onto suitable scaffolds as seed cells to repair bone defects successfully in an autologous setting. Previous studies have indicated that both undifferentiated BMSCs and ASCs exhibit immunosuppression and immunoprivilege properties. We compare the immuno-function of undifferentiated and osteo-differentiated ASCs in vitro and explore the feasibility of applying allogeneic ASCs to the repair of ulnar bone defects in the rabbit model. Our study demonstrates that allogeneic osteogenic differentiated ASCs maintain low immunogenicity and negative immunomodulation. The allogeneic osteogenic differentiated ASCs combined with demineralized bone matrix successfully regenerate ulnar bone defects in rabbits without immunosuppressive therapies.

Local injection of deferoxamine improves neovascularization in ischemic diabetic random flap by increasing HIF-1α and VEGF expression.

BACKGROUND: Although the systemic administration of deferoxamine (DFO) is protective in experimental models of normal ischemic flap and diabetic wound, its effect on diabetic flap ischemia using a local injection remains unknown. OBJECTIVE: To explore the feasibility of local injection of DFO to improve the survival of ischemic random skin flaps in streptozotocin (STZ)-induced diabetic mice. METHODS: Ischemic random skin flaps were made in 125 mice. Animals were divided into the DFO-treated (n = 20), PBS-treated (n = 16) and untreated (n = 16) groups. Surviving area, vessel density, and expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were evaluated on the seventh day after local injection. RESULTS: The viability of DFO-treated flap was significantly enhanced, with increased regional blood perfusion and capillary density compared with those in the two control groups. Fluorescence-activated cell sorting (FACS) analysis demonstrated a marked increase in systemic Flk-1+/CD11b- endothelial progenitor cells (EPCs) in DFO-treated mice. Furthermore, the expression of VEGF and HIF-1α was increased not only in diabetic flap tissue, but also in dermal fibroblasts cultured under hyperglycemic and hypoxic conditions. CONCLUSIONS: Local injection of DFO could exert preventive effects against skin flap necrosis in STZ-induced diabetic mice by elevating the expression of HIF-1α and VEGF, increased EPC mobilization, which all contributed to promote ischemic diabetic flap survival.

The distally based lateral sural neuro-lesser saphenous veno-fasciocutaneous flap: anatomical basis and clinical applications.

BACKGROUND: Soft tissue management around the lower third of the leg and foot presents a considerable challenge to the plastic surgeon. The aim of this research was to investigate the anatomical relationships of artery, nerve, vein and other adjacent structures in the posterolateral region of the calf, and our experience with using a distally based island flap pedicled with the lateral sural nerve and the lesser saphenous vein for soft tissue reconstruction of lower third of leg, foot, and ankle defects in 15 patients. MATERIALS AND METHODS: Five fresh cadavers (ten lower limbs) were infused with colored red latex. The origin of the nutrient vessel of the lesser saphenous vein and the lateral sural nerve was identified. Based on the anatomical studies, an island flap supplied by the vascular axis of the lesser saphenous vein and the lateral sural nerve was designed for clinical reparative applications in 15 cases. RESULTS: The nutrient vessel of the lesser saphenous vein and the lateral sural nerve originates from the superficial sural artery, musculocutaneous perforators of the posterior tibial artery, and septocutaneous perforators of the peroneal artery in different segment of the calf. Meanwhile, these vessels have many sub-branches nourishing subcutaneous tissue and skin, form a favorable vascular chain around the nerve and the vein, and also communicate with vascular plexus of superficial and deep fascia. Among 15 flaps, 13 showed complete survival (86.66 %), while marginal flap necrosis occurred in one patient (6.67 %) and distal wound dehiscence in another (6.67 %). Their appearance and function were satisfactory, with feeling maintained in the heel and lateral side of the foot. CONCLUSIONS: The distally based flap pedicled with the lateral sural nerve and lesser saphenous vein was a reliable source for repairing soft tissue defects in the lower leg and foot due to its advantages of infection control, high survival rate, and sufficient blood supply without the need to sacrifice a major blood vessel.

Clinical and anatomical study of the distally based lesser saphenous veno-lateral sural neurocutaneous flap for lower extremity coverage.

BACKGROUND: The distally based sural flap has been widely and successfully used to reconstruct soft tissue defects of the distal third of the lower leg and foot. Sensory loss and venous congestion are possible complications of this treatment, but there has been limited research focused on improving the sensory loss and veneous congestion. This study aimed to determine the spatial relationship between the lesser saphenous vein and the cutaneous nerves, the venous anatomy in the lower leg, and the nerve distribution in the lateral dorsum of the foot, and we presented our clinical experience. MATERIALS AND METHODS: Twenty freshly amputated lower limbs were dissected in the 2 h following amputation. The lesser saphenous vein, medial/lateral sural nerve, and sural nerve were identified. Based on the anatomical studies, an island flap supplied by the vascular axis of the lesser saphenous vein and the lateral sural nerve was designed for clinical reparative applications in 24 cases. RESULTS: We indicated the spatial relationship between the lesser saphenous vein and the cutaneous nerves and the venous anatomy in the lower leg. Among 24 flaps, 21 showed complete survival (87.5%), while marginal flap necrosis occurred in two patients (8.33%) and distal wound dehiscence in another (4.17%). No symptomatic neuromas were observed. Their appearance and functioning were satisfactory, with filling maintained in the heel and lateral side of the foot. CONCLUSION: The distally based lesser saphenous veno-lateral sural neurocutaneous flap provides effective coverage of variable-sized soft tissue defects on the lower third of the lower leg and foot, without sensory loss and venous congestion.

[The effect of adipose-derived stem cells on viability of random pattern skin flap in rabbits].

OBJECTIVE: To explore the effect of the adipose derived stem cells (ADSCs) on the survival of random pattern skin flap in rabbits. METHODS: ADSCs were isolated from fresh human fat and expanded in vitro for five passages. Then the characterization of ADSCs were determined by their CD marker profile and their ability to differentiate into osteogenic, adipogenic and chondrogenic lineages. On the back of the rabbits, two symmetric cephalic-based random pattern skin flaps were designed (6 cm x 2 cm). The right flaps were used as experimental groups with the contra-side flaps as control group. Human ADSCs were pre-labeled before seeding with fluorescent 3, 30-dioctadecyloxacarbocyanine perchlorate (DiO) dye. The experimental flaps evenly received 5-point injection of 2 x 10(6)Dio-labeled ADSCs resuspended in 0.5 ml of serum-free DMEM, while only 0.5 ml medium was injected into the control flaps. Seven days later, the survival rate of flaps was evaluated. The flaps underwent frozen section and were observed under the laser scanning confocal microscope to detect the fluorescence imaging. Flaps also underwent HE staining and were observed under light microscope to detect the vascular density. RESULTS: Compared with control group, there was a significant increase of flap survival rate in the experimental group (P < 0.01). Histological analysis also demonstrated a statistically significant increase in capillary density in the experimental group. CONCLUSIONS: It suggests that ADSCs have a better immune compatibility and potential for enhancing the blood supply of random pattern skin flaps.