Combining antibiotic-loaded bone cement-based free vastus lateralis muscle-sparing flap with split-thickness skin grafts: A reliable strategy for reconstructing diabetic foot ulcers at non-weight-bearing areas.

Diabetic foot ulcers (DFUs) present significant challenges due to their associated amputation rates, mortality, treatment complexity and excessive costs. Our earlier work introduced a wound surgical integrated treatment (WSIT) for DFUs, yielding promising outcomes. This study focuses on a specific WSIT protocol employing antibiotic-loaded bone cement (ALBC) in the first Stage, and free vastus lateralis muscle-sparing (VLMS) flaps and split-thickness skin grafts (STSGs) in the second stage to repair non-weight-bearing DFUs. From July 2021 to July 2023, seven DFU patients (aged 47-71 years) underwent this treatment. Demographic data, hospital stay and repair surgery times were collected. Histological and immunohistochemical analyses assessed angiogenesis, collagen deposition and inflammation. SF-36 questionnaire measured pre- and postoperative quality of life. Preoperative ultrasound Doppler showed that the peak blood flow velocity of the recipient area artery was significantly >30 cm/s (38.6 ± 6.8 cm/s) in all patients. Muscle flap sizes varied from 8 × 3.5 × 1 to 18 × 6 × 2 cm. The operation time of the repair surgery was 156.9 ± 15.08 minutes, and the hospital stay was 18.9 ± 3.3 days. Histological analysis proved that covering DFUs with ALBC induced membrane formation and increased collagen, neovascularization and M2 macrophages fraction while reducing M1 macrophages one. All grafts survived without amputation during a 7- to 24-month follow-up, during which SF-36 scores significantly improved. A combination of ALBC with free VLMS flaps and STSGs proved to be safe and effective for reconstructing non-weight-bearing DFUs. It rapidly controlled infection, enhanced life quality and foot function, and reduced hospitalization time. We advocate integrating this strategy into DFU treatment plans.

[Preliminary application of antibiotic bone cement directly inducing skin regeneration technology in repairing of wound in lateral toe flap donor area].

Objective: To investigate the feasibility and effectiveness of antibiotic bone cement directly inducing skin regeneration technology in the repairing of wound in the lateral toe flap donor area. Methods: Between June 2020 and February 2023, antibiotic bone cement directly inducing skin regeneration technology was used to repair lateral toe flap donor area in 10 patients with a total of 11 wounds, including 7 males and 3 females. The patients' age ranged from 21 to 63 years, with an average of 40.6 years. There were 3 cases of the distal segment of the thumb, 2 cases of the distal segment of the index finger, 1 case of the middle segment of the index and middle fingers, 1 case of the distal segment of the middle finger, and 3 cases of the distal segment of the ring finger. The size of the skin defect of the hand ranged from 2.4 cm×1.8 cm to 4.3 cm×3.4 cm. The disease duration ranged from 1 to 15 days, with an average of 6.9 days. The flap donor sites were located at fibular side of the great toe in 5 sites, tibial side of the second toe in 5 sites, and tibial side of the third toe in 1 site. The skin flap donor site wounds could not be directly sutured, with 2 cases having exposed tendons, all of which were covered with antibiotic bone cement. Results: All patients were followed up 6 months to 2 years, with an average of 14.7 months. All the 11 flaps survived and had good appearance. The wound healing time was 40-72 days, with an average of 51.7 days. There was no hypertrophic scar in the donor site, which was similar to the color of the surrounding normal skin; the appearance of the foot was good, and wearing shoes and walking of the donor foot were not affected. Conclusion: It is a feasible method to repair the wound in the lateral foot flap donor area with the antibiotic bone cement directly inducing skin regeneration technology. The wound heals spontaneously, the operation is simple, and there is no second donor site injury.

BioCloneBot: A versatile, low-cost, and open-source automated liquid handler.

Liquid handler systems can provide significant benefits to researchers by automating laboratory work, however, their unaffordable price provides a steep barrier to entry. Therefore, we provide the BioCloneBot, a versatile, low-cost, and open-source automated liquid handler. This system can be easily built with 3D-printed parts and readily available commercial components. The BioCloneBot is highly adaptive to user needs and facilitates various liquid handling tasks in research and diagnostics. Its user-friendly interface and programmable nature make it suitable for a wide range of applications, from small-scale experiments to larger laboratory setups. By utilizing BioCloneBot, researchers and scientists can streamline their liquid handling processes without the financial constraints posed by traditional systems. In this paper, we detail the design, construction, and validation of BioCloneBot, showcasing its precise control, accuracy, and repeatability in various liquid handling tasks. The open-source nature of the system encourages collaboration and customization, enabling researchers to contribute and adapt the technology to specific experimental requirements.

[Preliminary application of foldable pedicled latissimus dorsi myocutaneous flap for repairing soft tissue defects in shoulder and back].

Objective: To explore the feasibility and effectiveness of a foldable pedicled latissimus dorsi myocutaneous flap to repair soft tissue defects in the shoulder and back. Methods: Between August 2018 and January 2023, the foldable pedicled latissimus dorsi myocutaneous flaps were used to repair soft tissue defects in the shoulder and back of 8 patients. There were 5 males and 3 females with the age ranged from 21 to 56 years (mean, 35.4 years). Wounds were located in the shoulder in 2 cases and in the shoulder and back in 6 cases. The causes of injury were chronic infection of skin and bone exposure in 2 cases, secondary wound after extensive resection of skin and soft tissue tumor in 4 cases, and wound formation caused by traffic accident in 2 cases. Skin defect areas ranged from 14 cm×13 cm to 20 cm×16 cm. The disease duration ranged from 12 days to 1 year (median, 6.6 months). A pedicled latissimus dorsi myocutaneous flap was designed and harvested. The flap was divided into A/B flap and then were folded to repair the wound, with the donor area of the flap being pulled and sutured in one stage. Results: All 7 flaps survived, with primary wound healing. One patient suffered from distal flap necrosis and delayed healing was achieved after dressing change. The incisions of all donor sites healed by first intention. All patients were followed up 6 months to 4 years (mean, 24.7 months). The skin flap has a good appearance with no swelling in the pedicle. At last follow-up, 6 patients had no significant difference in bilateral shoulder joint motion, and 2 patients had a slight decrease in abduction range of motion compared with the healthy side. The patients' daily life were not affected, and linear scar was left in the donor site. Conclusion: The foldable pedicled latissimus dorsi myocutaneous flap is an ideal method to repair the soft tissue defect of shoulder and back with simple operation, less damage to the donor site, and quick recovery after operation.

Construction and study of a three-dimensional visualization model of superficial temporal artery branches: With an explicatory case.

BACKGROUND: The anatomical parameters of the superficial temporal artery branches were measured by a three-dimensional measurement method to provide anatomical reference for relevant clinical operations. METHODS: Seventy original images were selected who had cranial CTA examination. The patients were aged 30-79 years, with an average of 60.0 years, including 32 females and 38 males. After reconstructing the superficial temporal artery by professional medical 3D reconstruction software, its anatomical parameters were measured. RESULTS: The length of the secondary branches of the frontal branch of the superficial temporal artery were 47.6 ± 23.6 mm and 37.3 ± 21.6 mm in males and females, respectively, with a statistically significant difference. The length of the secondary branches of the parietal branch of the superficial temporal artery were 39.6 ± 20.4 mm and 49.2 ± 20.3 mm in young and middle-aged people and older people respectively, which were statistically different. The remaining measures were not statistically different across gender and age groups. The frontal branch of the superficial temporal artery was divided into three types, and the parietal branch of the superficial temporal artery was divided into two types. CONCLUSIONS: The anatomical parameters of the superficial temporal artery branches can be accurately measured by means of 3D visualization, providing an anatomical reference for relevant clinical operations.

GehB Inactivates Lipoproteins to Delay the Healing of Acute Wounds Infected with Staphylococcus aureus.

Staphylococcus aureus is one of the most prevalent bacteria found in acute wounds. S. aureus produces many virulence factors and extracellular enzymes that contribute to bacterial survival, dissemination, and pathogenicity. Lipase GehB is a glycerol ester hydrolase that hydrolyzes triglycerides to facilitate the evasion of S. aureus from host immune recognition. However, the role and mechanism of lipase GehB in skin acute wound healing after S. aureus infection remain unclear. In this study, we found that the gehB gene deletion mutant (USA300ΔgehB) stimulated significantly higher levels of pro-inflammatory cytokines in RAW264.7 and Toll-like receptor 2 (TLR2)-transfected HEK293 cells than the wild-type USA300 strain did. Recombinant GehB-His treated lipoprotein (Lpp) reduced stimulation of TLR2-dependent TNF-α production by RAW264.7 macrophages. GehB delayed the skin acute wound healing in BALB/c mice infected with S. aureus, while wound healing was similar in C57BL/6 TLR2-/- mice infected with either wild-type USA300 or USA300ΔgehB. In BALB/c mice, we also observed more bacterial survival, less leukocyte recruitment, lower IL-8 production, and adipocyte differentiation in USA300-infected skin acute wound tissues than those in USA300ΔgehB-challenged ones. Our data indicated that GehB inactivates lipoproteins to shield S. aureus from innate immune killing, resulting in delayed the healing of skin acute wounds infected with S. aureus.

[Application of plantar medial thin skin flaps preserving plantar fascia with its superficial fascia tissue to repair skin defects in hands and feet].

Objective: To explore the feasibility and effectiveness of plantar medial thin skin flaps preserving plantar fascia with its superficial fascia tissue to repair skin defects in hands and feet. Methods: Between July 2017 and January 2023, 35 cases of hand and foot defects were repaired with plantar medial thin skin flaps preserving plantar fascia with its superficial fascia tissue (13 pedicled flaps and 22 free flaps). There were 18 males and 17 females, with an average age of 38.8 years (range, 8-56 years). Thirty cases of defects were caused by trauma, and the interval between injury and admission ranged from 2 to 6 hours (mean, 3.3 hours). Three cases were ulcer wounds with a course of 3.0, 3.8, and 7.0 months, respectively. Two cases were malignant melanoma. Eight cases of wounds located in the fingers, 13 cases in the palm, 12 cases in the heel, and 2 cases in the distal foot. The size of skin defects ranged from 4.0 cm×3.5 cm to 12.0 cm×10.0 cm, and the size of flap ranged from 5.0 cm×4.5 cm to 13.0 cm×11.0 cm. The donor sites were repaired with skin grafts. Results: All flaps were survived and the wounds healed by first intention after operation. The partial necrosis at the edge of the skin graft occurred in 1 case, which healed after dressing change; the other skin grafts survived successfully. All patients were followed up 6-24 months (mean, 18 months). The flaps exhibited similar color and thickness to the surrounding hand and foot skin. Two-point discrimination ranged from 7 to 10 mm in the flaps with an average of 8 mm. The donor sites had no painful scars or sensory abnormalities. Foot and ankle functions were good and gaits were normal. Conclusion: Application of plantar medial thin skin flaps preserving plantar fascia with its superficial fascia tissue to repair skin defects in hands and feet had good flap shape, high survival rate of skin graft at the donor site, and no obvious complications.

A Modified Suture Technique to Improve Scar Appearance in Wounds Under High Tension.

ABSTRACT: The purpose of this study was to introduce a modified suture technique and to compare its effects on skin scar formation with 2 traditional suture methods: simple interrupted suture (SIS) and vertical mattress suture (VMS). Three groups of healthy adult female Sprague-Dawley rats were selected (6 replicates in each group), and the full-thickness skin of 5 cm × 0.2 cm was cut off on the back of the rats after anesthesia. The wounds were then sutured using 1 of the 3 methods for each group: SIS, VMS, and a newly introduced modified vertical mattress suture (M-VMS) technique with the needle reinsertion at the exit point. A traction device was installed on the back of the rats to achieve high tension wounds. The tensile distance was increased by 1 mm every day for 20 days. After 20 days of healing, the hematoxylin-eosin staining method was used for observation of scar morphology. The collagen production rate was measured by Masson staining, and the type I collagen and type III collagen were detected by the immunofluorescence method. Immunohistochemical staining was used to detect the expression of myofibroblast marker α-smooth muscle actin, and real-time quantitative polymerase chain reaction and Western blot techniques were used to detect the expressions of transforming growth factors TGFß1, TGFß2, and TGFß3 to understand the mechanisms of scar formation. Results showed that the quantity and density of collagen fibers were both lower in the M-VMS group than in the other 2 groups. Immunofluorescence results showed that type I collagen was significantly lower, whereas type III collagen was significantly higher in the M-VMS group than in the other 2 groups. The expressions of α-smooth muscle actin and TGFß1 both were lower in the M-VMS group than in the other 2 groups. The expression of TGFß2 and TGFß3 had no obvious difference among the 3 groups. For wounds under high tension, compared with SIS and VMS methods, the M-VMS technique we proposed can reduce scar formation due to the reduction of collagen formation, myofibroblast expression, and TGFß1 expression.

[Effectiveness of tibial transverse transport combined with modified neurolysis in treatment of diabetic foot ulcers].

Objective: To investigate the effectiveness of tibial transverse transport (TTT) combined with modified neurolysis in treatment of diabetic foot ulcer (DFU) through a prospective randomized controlled study. Methods: The patients with DFU and diabetic peripheral neuropathy, who were admitted between February 2020 and February 2022, were selected as the research objects, of which 31 cases met the selection criteria and were included in the study. The patients were divided into two groups by random number table method. The 15 patients in the trial group were treated with TTT combined with modified neurolysis, and the 16 patients in the control group received treatment with TTT alone. There was no significant difference in gender, age, duration of DFU, ulcer area, Wagner classification, as well as preoperative foot skin temperature, visual analogue scale (VAS) score, ankle-brachial index (ABI), motor nerve conduction velocity (MNCV) of the common peroneal nerve, MNCV of the tibial nerve, MNCV of the deep peroneal nerve, two-point discrimination (2-PD) of heel, and cross-sectional area (CSA) of the common peroneal nerve between the two groups ( P>0.05). The time for ulcer healing, foot skin temperature, VAS scores, ABI, 2-PD of heel, and CSA of the common peroneal nerve before operation and at 6 and 12 months after operation were recorded and compared between groups. The differences in MNCV of the common peroneal nerve, MNCV of the tibial nerve, and MNCV of the deep peroneal nerve between pre-operation and 12 months after operation were calculated. Results: All patients in both groups were followed up 12-24 months (mean, 13.9 months). The surgical incisions in both groups healed by first intention and no needle tract infections occurred during the bone transport phase. Ulcer wounds in both groups healed successfully, and there was no significant difference in the healing time ( P>0.05). During the follow-up, there was no ulcer recurrences. At 12 months after operation, the MNCV of the common peroneal nerve, the MNCV of the tibial nerve, and the MNCV of the deep peroneal nerve in both groups accelerated when compared to preoperative values ( P<0.05). Furthermore, the trial group exhibited a greater acceleration in MNCV compared to the control group, and the difference was significant ( P<0.05). The foot skin temperature, VAS score, ABI, 2-PD of heel, and CSA of the common peroneal nerve at 6 and 12 months after operation significantly improved when compared with those before operation in both groups ( P<0.05). The 2-PD gradually improved over time, showing significant difference ( P<0.05). The 2-PD of heel and VAS score of the trial group were superior to the control group, and the differences were significant ( P<0.05). There was no significant difference in ABI, foot skin temperature, and CSA of the common peroneal nerve between groups after operation ( P>0.05). Conclusion: Compared with TTT alone, the TTT combined with modified neurolysis for DFU can simultaneously solve both microcirculatory disorders and nerve compression, improve the quality of nerve function recovery, and enhance the patient's quality of life.

Neural grafts containing exosomes derived from Schwann cell-like cells promote peripheral nerve regeneration in rats.

Background: Schwann cell-like cells (SCLCs), differentiated from mesenchymal stem cells, have shown promising outcomes in the treatment of peripheral nerve injuries in preclinical studies. However, certain clinical obstacles limit their application. Hence, the primary aim of this study was to investigate the role of exosomes derived from SCLCs (SCLCs-exo) in peripheral nerve regeneration. Methods: SCLCs were differentiated from human amniotic mesenchymal stem cells (hAMSCs) in vitro and validated by immunofluorescence, real-time quantitative PCR and western blot analysis. Exosomes derived from hAMSCs (hAMSCs-exo) and SCLCs were isolated by ultracentrifugation and validated by nanoparticle tracking analysis, WB analysis and electron microscopy. A prefabricated nerve graft was used to deliver hAMSCs-exo or SCLCs-exo in an injured sciatic nerve rat model. The effects of hAMSCs-exo or SCLCs-exo on rat peripheral nerve injury (PNI) regeneration were determined based on the recovery of neurological function and histomorphometric variation. The effects of hAMSCs-exo or SCLCs-exo on Schwann cells were also determined via cell proliferation and migration assessment. Results: SCLCs significantly expressed the Schwann cell markers glial fibrillary acidic protein and S100. Compared to hAMSCs-exo, SCLCs-exo significantly enhanced motor function recovery, attenuated gastrocnemius muscle atrophy and facilitated axonal regrowth, myelin formation and angiogenesis in the rat model. Furthermore, hAMSCs-exo and SCLCs-exo were efficiently absorbed by Schwann cells. However, compared to hAMSCs-exo, SCLCs-exo significantly promoted the proliferation and migration of Schwann cells. SCLCs-exo also significantly upregulated the expression of a glial cell-derived neurotrophic factor, myelin positive regulators (SRY-box transcription factor 10, early growth response protein 2 and organic cation/carnitine transporter 6) and myelin proteins (myelin basic protein and myelin protein zero) in Schwann cells. Conclusions: These findings suggest that SCLCs-exo can more efficiently promote PNI regeneration than hAMSCs-exo and are a potentially novel therapeutic approach for treating PNI.

[Clinical application of microdissected thin thoracodorsal artery perforator flaps for repair of diabetic foot ulcers].

Objective: To explore the effectiveness of microdissected thin thoracodorsal arterial perforator flap (TDAP) in repairing diabetic foot ulcers (DFUs). Methods: The clinical data of 11 patients with DFUs admitted between March 2020 and February 2021 were retrospectively analyzed, including 5 males and 6 females, aged from 22 to 67 years, with an average of 49.3 years. There were 10 cases of type 2 diabetes and 1 case of type 1 diabetes; the duration of diabetes ranged from 3 months to 25 years (median, 8 months). The duration of DFUs ranged from 6 days to 120 months (median, 1 month). There were 6 cases of grade 3 and 5 cases of grade 4 according to Wagner classification. The tissue necrosis and purulent secretions were found in all ulcer wounds, as well as different degrees of tendon and bone exposure; skin defects ranged from 5 cm×3 cm to 17 cm×6 cm. The DFUs were repaired by microdissected thin TDAP, including 6 cases of flaps (including 1 case of lobulated flap), ranging from 10.0 cm×4.5 cm to 26.0 cm×7.0 cm; 5 cases of chimeric perforator flaps, the range of the flap was 10.0 cm×4.5 cm to 16.0 cm×5.5 cm, and the range of the muscle flap was 6 cm×2 cm to 10 cm×3 cm. The donor site was sutured directly. Results: The operation time ranged from 3.42 to 11.17 hours, with an average of 5.92 hours. All 11 flaps survived and no vascular crisis occurred; 1 patient had a sinus at the edge of the flap, and the surgical area healed well after dressing change. All 11 patients were followed up 6-12 months, with an average of 9 months. The flap texture was good, the recipient site was in good shape, and there was no swelling; the foot contour was good, the shoes were comfortable to wear, and the movement was good. The incision at the donor site healed by first intention, leaving only linear and concealed scar, without obvious depression deformity, and the shoulder joint function was good. Conclusion: On the premise of ensuring sufficient blood supply to the lower extremities and strengthening perioperative management, the microdissected thin TDAP to repair DFUs wounds can achieve better effectiveness and appearance; however, the prolonged operation time increases the probability of anesthesia and surgical risks in patients with DFUs.

Schwann cell­like cells derived from human amniotic mesenchymal stem cells promote sciatic nerve repair through an exosome­induced SOX2/FN1 pathway in vitro.

The unsatisfactory sensory function reconstruction after flap transplantation to repair tissue defects and reconstruct organs results in decreased quality of life. Schwann cells (SCs) can promote sensory function reconstruction, but the underlying mechanism is not completely understood. The aim of the present study was to explore the in­depth mechanism underlying SCs in sensory function reconstruction. Sciatic nerve transection and a repair animal model were performed to evaluate the effect of SC­like cells (iSCs) and a neurotrophin 3 (NT­3) chitosan conduit. SC RNA­seq data indicated that the SOX2/fibronectin 1 (FN1) axis promoted proliferation and migration, which are the cytological bases of nerve regeneration. Subsequently, the effects of SOX2, FN1 and exosomes secreted by iSCs on SC proliferation and migration were assessed using scratch wound and EdU assays, respectively. The RNA­seq of SCs indicated that SOX2 overexpression increased iSC viability and migration. Furthermore, SOX2 increased FN1 expression to promote nerve recovery by fibronectin fibrillogenesis. In addition, exosomes secreted by iSCs increased SC viability and migration. In conclusion, iSCs with an NT­3 chitosan conduit promoted sciatic nerve recovery via the SOX2/FN1 axis and exosomes secreted by iSCs. Therefore, the present study identified potential effective therapeutic approaches for sciatic nerve repair.

[Repair of complex wounds of limbs with free lobed perforator flaps].

OBJECTIVE: To explore the effectiveness of free lobed perforator flaps in repairing of complex wounds of limbs. METHODS: Between January 2018 and January 2021, 10 patients with complex wounds of limbs were admitted. There were 7 males and 3 females, aged from 32 to 64 years, with an average age of 45 years. There were 4 cases of traffic accident injuries, 3 cases of machine strangulation injuries, 1 case of machine crush injury, and 2 cases of heavy object crush injuries. There were 5 cases of upper limb wounds and 5 cases of lower limb wounds. The size of wounds ranged from 11 cm×10 cm to 25 cm×18 cm. The wounds were repaired with tri-lobed flaps of the descending branch of the lateral femoral circumflex artery in 7 cases, four-lobed flaps in 2 cases, and with tri-lobed flaps of the descending branch of the lateral femoral circumflex artery combined with oblique branch in 1 case. The size of flaps ranged from 12.0 cm×10.5 cm to 28.0 cm×12.0 cm. The donor sites were sutured directly in 9 cases and repaired with superficial iliac circumflex artery perforator flap in 1 case. RESULTS: Sinus formed at the edge of the flap in 1 patient, which healed after dressing change and drainage; other flaps survived well, and the wounds healed by first intention. The skin flap at donor site survived, and the incisions healed by first intention. All patients were followed up 6-24 months (mean, 11 months). All flaps had good appearance and function, and linear scars were left at the donor site without obvious complications. CONCLUSION: Free lobed perforator flap is an alternative method to repair complex wounds of limbs with high safety, good effectiveness, and less complications.

Outcomes of integrated surgical wound treatment mode based on tibial transverse transport for diabetic foot wound.

Background: Diabetic foot ulcer (DFU) is frequently difficult to heal and finally leads to amputation, resulting in high mortality rate in diabetic patients. To date, effective and optimal therapies are still lacking. This study aims to investigate the efficacy of integrated surgical wound treatment (ISWT) mode on diabetic foot wound. Methods: From January 2021 to December 2021, 13 diabetic foot patients with Wagner grade 3 to 4 were treated with ISWT mode, which combined TTT technique with debridement, induced membrane technique, vacuum sealing drainage (VSD) technique and skin grafting technique. The time of wound healing, the skin temperature at midpoint of dorsum of affected foot (T), visual analogue scale (VAS) score and ankle-brachial index (ABI) was measured before and after surgery. CTA examination of the lower extremity arteries was performed at the end of the cortex transport to evaluate the small arteriolar formation of the lower extremity. The complications occurred in each patient were recorded. Results: 13 patients with age ranging from 45 to 66 years were followed up for 3 to 13 months. All patients healed completely without amputation being performed, no serious complications were found except for one case of nail channel infection. The mean healing time was 25.8 ± 7.8 days, with a range of 17 to 39 days. The mean time of carrying external fixation scaffolds and resuming walking was 71.8 ± 10.0 and 30.8 ± 9.1 days, with a range of 56 to 91 days and 18 to 45 days, respectively. The skin temperature at midpoint of dorsum of affected foot (T), VAS and ABI was all improved significantly at 3 months after surgery. Furthermore, CTA examination showed an increase in the number of lower extremity arteries and a thickening in the size of small arteriolar compared with those of pre-operative, and the collateral circulation of lower extremity was established and interweaved into a network. Conclusion: Integrated surgical treatment of diabetic foot wound can achieve satisfactory clinical results.

[Free transplantation of medial plantar Flow-through venous flap for primary repairing children's finger wounds with digital artery defect].

OBJECTIVE: To explore the feasibility and effectiveness of free transplantation of medial plantar Flow-through venous flap for primary repairing children's finger wounds with digital artery defect. METHODS: Between July 2016 and October 2020, 9 children who suffered finger wounds with digital artery defect were primary repaired with free transplantation of medial plantar Flow-through venous flap. There were 6 boys and 3 girls, with an average age of 6.8 years (range, 4-13 years). The defects were caused by heavy weight puncture injury in 5 cases and strangulation injury in 4 cases. Among them, there were 3 cases of index finger wounds, 3 cases of middle finger wounds, 2 cases of ring finger wounds, and 1 case of little finger wounds. The wound area ranged from 1.8 cm×1.5 cm to 4.0 cm×2.5 cm. The time from injury to operation was 1.3-8.6 hours, with an average of 4.8 hours. The flap area ranged from 2.0 cm×1.6 cm to 4.2 cm×2.6 cm. After the flaps were inverted, the veins were used to bridge the finger arteries while repairing the wounds. The donor site of the foot was sutured directly in 4 cases, and repaired with full-thickness skin grafts in 5 cases. RESULTS: All flaps survived, and hand wounds healed by first intention; 8 cases of foot donor site wounds healed by first intention, and 1 case had partial necrosis in the marginal area of the skin graft, which healed after dressing change. All 9 children were followed up 3-24 months, with an average of 9 months. The color and texture of the flap were similar to those of the surrounding normal skin, and the protective feeling was restored. The two-point discrimination of the flap was 7-10 mm, with an average of 8 mm. At last follow-up, according to the upper limb function evaluation standard of Hand Surgery Society of Chinese Medical Association, the finger function was excellent in 5 cases and good in 4 cases. There was no ulcer formation and scar hyperplasia in the foot donor site, which did not affect walking. CONCLUSION: The free transplantation of medial plantar Flow-through venous flap is an ideal repair method for repairing children's finger wounds with digital artery defect. It has the advantages of simple flap extraction, thin flap, similar color and texture to the skin of the hand, and concealed donor site.

[Application of modified three longitudinal and five transverse method in perforating branch location before anterolateral thigh perforator flap repair].

OBJECTIVE: To explore the feasibility and accuracy of modified three longitudinal and five transverse method in locating perforating branches before anterolateral thigh perforator flap (ALTP) repair. METHODS: Between January 2019 and December 2019, 41 patients with skin and soft tissue defects were repaired with ALTP. There were 31 males and 10 females. The age ranged from 18 to 61 years, with an average of 32 years. The soft tissue defects were caused by trauma in 38 cases, and the time from injury to operation was 3-7 days, with an average of 4 days. The wounds left after excision of scar contracture deformity because of burn in 3 cases. Soft tissue defects located at upper limbs in 16 cases and lower limbs in 25 cases. The size of soft tissue defects ranged from 10 cm×4 cm to 25 cm×12 cm. Before operation, zonesⅠ, Ⅱ, Ⅲ, and Ⅳwere formed on the anterolateral thigh by modified three longitudinal and five transverse method. The perforating branches were detected in these four zones by Doppler ultrasound, and the skin flaps were designed according to the wound area. The perforating branches were explored during operation, and the distribution and types of perforating branches in each zone and the relationship between perforating branches and lateral femoral cutaneous nerve were observed. The ALTP with the size of 12 cm×5 cm to 30 cm×10 cm was used to repair the wound, and the donor site was sutured directly or repaired with the flap. RESULTS: A total of 117 perforating branches were detected in 41 patients before operation, and 111 perforating branches were found during operation, with a false positive rate of 5%. The probability of perforating branches in zonesⅠ, Ⅱ, Ⅲ, and Ⅳ were 56%, 73%, 76%, and 66% respectively, and the false positive rates were -9%, 7%, 16%, and 4%, respectively. All perforating branches located near the trunk of lateral femoral cutaneous nerve, especially in posterolateral area. There were only 1 perforating branch in 6 cases, 2 perforating branches in 12 cases, 3 perforating branches in 10 cases, and 4 perforating branches in 13 cases. The main types of perforating branches in zonesⅠ, Ⅱ, Ⅲ, and Ⅳ were transverse perforating branches, oblique perforating branches, descending perforating branches, and descending perforating branches, respectively. Partial distal necrosis occurred in 2 cases and complete necrosis occurred in 1 case after operation, and the wounds were repaired with skin grafts. The remaining 38 flaps survived successfully, and the wounds and the incisions of donor sites healed by first intention. All patients were followed up 3 to 12 months, with an average of 6 months. The appearance and texture of the skin flap were acceptable, and linear scar remained in the donor site. CONCLUSION: It can simply locate and distinguish the perforating branches and better protect the lateral femoral cutaneous nerve by using the modified three longitudinal and five transverse method before ALTP repair.

Exosomes of adult human fibroblasts cultured on 3D silk fibroin nonwovens intensely stimulate neoangiogenesis.

BACKGROUND: Bombyx mori silk fibroin is a biomacromolecule that allows the assembly of scaffolds for tissue engineering and regeneration purposes due to its cellular adhesiveness, high biocompatibility and low immunogenicity. Earlier work showed that two types of 3D silk fibroin nonwovens (3D-SFnws) implanted into mouse subcutaneous tissue were promptly vascularized via undefined molecular mechanisms. The present study used nontumorigenic adult human dermal fibroblasts (HDFs) adhering to a third type of 3D-SFnws to assess whether HDFs release exosomes whose contents promote neoangiogenesis. METHODS: Electron microscopy imaging and physical tests defined the features of the novel carded/hydroentangled 3D-SFnws. HDFs were cultured on 3D-SFnws and polystyrene plates in an exosome-depleted medium. DNA amounts and D-glucose consumption revealed the growth and metabolic activities of HDFs on 3D-SFnws. CD9-expressing total exosome fractions were from conditioned media of 3D-SFnws and 2D polystyrene plates HDF cultures. Angiogenic growth factors (AGFs) in equal amounts of the two groups of exosomal proteins were analysed via double-antibody arrays. A tube formation assay using human dermal microvascular endothelial cells (HDMVECs) was used to evaluate the exosomes' angiogenic power. RESULTS: The novel features of the 3D-SFnws met the biomechanical requirements typical of human soft tissues. By experimental day 15, 3D-SFnws-adhering HDFs had increased 4.5-fold in numbers and metabolized 5.4-fold more D-glucose than at day 3 in vitro. Compared to polystyrene-stuck HDFs, exosomes from 3D-SFnws-adhering HDFs carried significantly higher amounts of AGFs, such as interleukin (IL)-1α, IL-4 and IL-8; angiopoietin-1 and angiopoietin-2; angiopoietin-1 receptor (or Tie-2); growth-regulated oncogene (GRO)-α, GRO-ß and GRO-γ; matrix metalloproteinase-1; tissue inhibitor metalloproteinase-1; and urokinase-type plasminogen activator surface receptor, but lesser amounts of anti-angiogenic tissue inhibitor metalloproteinase-2 and pro-inflammatory monocyte chemoattractant protein-1. At concentrations from 0.62 to 10 µg/ml, the exosomes from 3D-SFnws-cultured HDFs proved their angiogenic power by inducing HDMVECs to form significant amounts of tubes in vitro. CONCLUSIONS: The structural and mechanical properties of carded/hydroentangled 3D-SFnws proved their suitability for tissue engineering and regeneration applications. Consistent with our hypothesis, 3D-SFnws-adhering HDFs released exosomes carrying several AGFs that induced HDMVECs to promptly assemble vascular tubes in vitro. Hence, we posit that once implanted in vivo, the 3D-SFnws/HDFs interactions could promote the vascularization and repair of extended skin wounds due to burns or other noxious agents in human and veterinary clinical settings.

A Subpopulation of Schwann Cell-Like Cells With Nerve Regeneration Signatures Is Identified Through Single-Cell RNA Sequencing.

Schwann cell-like cells (SCLCs) derived from human amniotic mesenchymal stem cells (hAMSCs) have been shown to promote peripheral nerve regeneration, but the underlying molecular mechanism was still poorly understood. In order to investigate the heterogeneity and potential molecular mechanism of SCLCs in the treatment of peripheral nerve regeneration at a single cell level, single-cell RNA sequencing was applied to profile single cell populations of hAMSCs and SCLCs. We profiled 6,008 and 5,140 single cells from hAMSCs and SCLCs, respectively. Based on bioinformatics analysis, pathways associated with proliferation, ECM organization, and tissue repair were enriched within both populations. Cell cycle analysis indicated that single cells within these two populations remained mostly in the G0/G1 phase. The transformation of single cells from hAMSCs to SCLCs was characterized by pseudotime analysis. Furthermore, we identified a subpopulation of SCLCs that highly expressed genes associated with Schwann cell proliferation, migration, and survival, such as JUN, JUND, and NRG1., Genes such as PTGS2, PITX1, VEGFA, and FGF2 that promote nerve regeneration were also highly expressed in single cells within this subpopulation, and terms associated with inflammatory and tissue repair were enriched in this subpopulation by pathway enrichment analysis. Our results indicate that a subpopulation of SCLCs with nerve regeneration signatures may be the key populations that promote nerve regeneration.

[Application of Zunyi's Suture Method for donor site of anterolateral thigh flap].

OBJECTIVE: To investigate the effectiveness of multiple tension reduction suture of in-situ return needle vertical mattress suture and in-situ return needle horizontal mattress suture combination with intradermal intermittent continuous suture (denominated as Zunyi's Suture Method) on suturing the donor site of the anterolateral thigh flap. METHODS: Between January 2019 and December 2019, 62 patients were treated with anterolateral thigh flaps to repair wounds. There were 46 males and 16 females, aged 9-67 years (mean, 31 years). The size of anterolateral thigh flap ranged from 6 cm×5 cm to 25 cm×7 cm. The donor site of the flap was sutured directly by the Zunyi's Suture Method. The skin on both sides of the incision was advanced to the middle, and the wound edge was attached and in a state of negative tension. The intradermal suture line was removed at 7 days after operation. The complications and scars at donor site were observed during follow-up. The Vancouver Scar Scale was used to assess the appearance of scars and the width of scars were measured at 6 months after operation. RESULTS: The flaps survived smoothly, and the wounds healed by first intention. The incisions at donor sites healed by first intention at 2 to 3 weeks after operation. All patients were followed up 7-16 months, with an average of 10.7 months. There was no ischemic necrosis of the donor site or skin threading. There was pigmentation of the needle back point in the early stage, and the pigmentation completely disappeared after 3 to 6 months without scar hyperplasia. At 6 months after operation, liner scars were achieved in all the patients with an average Vancouver Scar Scale score of 2.5 (range, 1.0-3.5) and an average width of 2.4 mm (range, 0.8-9.1 mm). CONCLUSION: The suture of the donor site of the anterolateral thigh flap with Zunyi's Suture Method can effectively reduce the tension on wound edges and scar hyperplasia.

miR-146a-3p suppressed the differentiation of hAMSCs into Schwann cells via inhibiting the expression of ERBB2.

Human amniotic mesenchymal stem cells (hAMSCs) can be differentiated into Schwann-cell-like cells (SCLCs) in vitro. However, the underlying mechanism of cell differentiation remains unclear. In this study, we explored the phenotype and multipotency of hAMSCs, which were differentiated into SCLCs, and the expression of nerve repair-related Schwann markers, such as S100 calcium binding protein B (S-100), TNF receptor superfamily member 1B (P75), and glial fibrillary acidic protein (GFAP) were observed to be significantly increased. The secreted functional neurotrophic factors, like brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3), were determined and also increased with the differentiation time. Moreover, miR-146a-3p, which significantly decreased during the differentiation of hAMSCs into SCLCs, was selected by miRNA-sequence analysis. Further molecular mechanism studies showed that Erb-B2 receptor tyrosine kinase 2 (ERBB2) was an effective target of miR-146a-3p and that miR-146a-3p down-regulated ERBB2 expression by binding to the 3'-UTR of ERBB2. The expression of miR-146a-3p markedly decreased, while the mRNA levels of ERBB2 increased with the differentiation time. The results showed that down-regulating miR-146a-3p could promote SC lineage differentiation and suggested that miR-146a-3p negatively regulated the Schwann-like phenotype differentiation of hAMSCs by targeting ERBB2. The results will be helpful to establish a deeper understanding of the underlying mechanisms and find novel strategies for cell therapy.