Purification and Characterization of Extracellular Vesicles from Human Adipose-Derived Mesenchymal Stem Cells.

Human adipose-derived mesenchymal stem cells (ADSCs) can promote the regeneration and reconstruction of various tissues and organs. Recent research suggests that their regenerative function may be attributed to cell-cell contact and cell paracrine effects. The paracrine effect is an important way for cells to interact and transfer information over short distances, in which extracellular vesicles (EVs) play a functional role as carriers. There is significant potential for ADSC EVs in regenerative medicine. Multiple studies have reported on the effectiveness of these methods. Various methods for extracting and isolating EVs are currently described based on principles such as centrifugation, precipitation, molecular size, affinity, and microfluidics. Ultracentrifugation is regarded as the gold standard for isolating EVs. Nevertheless, a meticulous protocol to highlight precautions during ultracentrifugation is still absent. This study presents the methodology and crucial steps involved in ADSC culture, supernatant collection, and EV ultracentrifugation. However, even though ultracentrifugation is cost-effective and requires no further treatment, there are still some inevitable drawbacks, such as a low recovery rate and EV aggregation.

[Research progress of antibacterial hydrogel in treatment of infected wounds].

Objective: To review the research progress of new antibacterial hydrogels in the treatment of infected wounds in the field of biomedicine, in order to provide new methods and ideas for clinical treatment of infected wounds. Methods: The research literature on antibacterial hydrogels at home and abroad was extensively reviewed in recent years, and the antibacterial hydrogels for the treatment of infected wounds were classified and summarized. Results: Antibacterial hydrogels can be divided into three categories: inherent antibacterial hydrogels, antibacterial agent release hydrogels, and environmental response antibacterial hydrogels. The advantages and disadvantages of antibacterial materials, antibacterial mechanism, antibacterial ability, and biocompatibility were discussed respectively. Inherent antibacterial hydrogels have the characteristics of wide source, low cost, and simple preparation, but their antibacterial ability is relatively weak. New antimicrobial substances are added to antibacterial agent release hydrogels, such as antimicrobial peptides, metal ions, graphene materials, etc., providing a new therapeutic strategy for alternative antibiotic therapy. On the basis of the antibacterial material, environmental promoting factors such as photothermal effect, pH value, and magnetic force are added to the environmental response antibacterial hydrogels, which synergically enhances the antibacterial ability of the hydrogel, improves the precise regulation function and bionic effect of the hydrogel. Conclusion: The selection of a variety of materials, the addition of a variety of antibacterial agents, and the effect of various promoting factors make composite hydrogels show multiple characteristics. The development of antibacterial hydrogels that can effectively address practical clinical applications remains a significant challenge. In the future, expanding the application range of antibacterial hydrogels, constructing drug-loaded hydrogels, and developing intelligent hydrogels are still new areas that need to be explored and studied.

Construction and validation of a deterioration model for elderly COVID-19 Sub-variant BA.2 patients.

Rationale: COVID-19 pandemic has imposed tremendous stress and burden on the economy and society worldwide. There is an urgent demand to find a new model to estimate the deterioration of patients inflicted by Omicron variants. Objective: This study aims to develop a model to predict the deterioration of elderly patients inflicted by Omicron Sub-variant BA.2. Methods: COVID-19 patients were randomly divided into the training and the validation cohorts. Both Lasso and Logistic regression analyses were performed to identify prediction factors, which were then selected to build a deterioration model in the training cohort. This model was validated in the validation cohort. Measurements and main results: The deterioration model of COVID-19 was constructed with five indices, including C-reactive protein, neutrophil count/lymphocyte count (NLR), albumin/globulin ratio (A/G), international normalized ratio (INR), and blood urea nitrogen (BUN). The area under the ROC curve (AUC) showed that this model displayed a high accuracy in predicting deterioration, which was 0.85 in the training cohort and 0.85 in the validation cohort. The nomogram provided an easy way to calculate the possibility of deterioration, and the decision curve analysis (DCA) and clinical impact curve analysis (CICA)showed good clinical net profit using this model. Conclusion: The model we constructed can identify and predict the risk of deterioration (requirement for ventilatory support or death) in elderly patients and it is clinically practical, which will facilitate medical decision making and allocating medical resources to those with critical conditions.

Ginseng polysaccharide reduces autoimmune hepatitis inflammatory response by inhibiting PI3K/AKT and TLRs/NF-κB signaling pathways.

BACKGROUND: Ginseng polysaccharides (GP) have been found to exhibit significant immune regulatory effects, making them a promising candidate for treating immune-related diseases. However, their mechanism of action in immune liver injury is not yet clear. The innovation of this study lies in exploring the mechanism of action of ginseng polysaccharides (GP) in immune liver injury. While GP has been previously identified for its immune regulatory effects, this study aims to provide a clearer understanding of its therapeutic potential for immune-related liver diseases. PURPOSE: The purpose of this study is to characterize low molecular weight gingeng polysaccharides (LGP), investigate their effect on ConA-induced autoimmune hepatitis (AIH), and identify their potential molecular mechanisms. METHODS: LGP was extracted and purified using water-alcohol precipitation, DEAE-52 cellulose column, and Sephadex G200. And its structure was analyzed. It was then evaluated for anti-inflammatory and hepatoprotective effects in ConA-induced cells and mice, assessing cellular viability and inflammation with Cell Counting Kit-8 (CCK-8), Reverse Transcription-polymerase Chain Reaction (RT-PCR), and Western Blot, and hepatic injury, inflammation, and apoptosis with various biochemical and staining methods. RESULTS: LGP is a polysaccharide composed of glucose (Glu), galactose (Gal), and arabinose (Ara), with a molar ratio of 12.9:1.6:1.0. LGP has a low crystallinity amorphous powder structure and is free from impurities. LGP enhances cell viability and reduces inflammatory factors in ConA-induced RAW264.7 cells and inhibits inflammation and hepatocyte apoptosis in ConA-induced mice. LGP inhibits Phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and Toll-like receptors/Nuclear factor kappa B (TLRs/NF-κB) signaling pathways in vitro and in vivo to treat AIH. CONCLUSIONS: LGP was successfully extracted and purified, exhibiting potential as a treatment for ConA-induced autoimmune hepatitis due to its ability to inhibit the PI3K/AKT and TLRs/NF-κB signaling pathways and protect liver cells from damage.

C-reactive protein to lymphocyte ratio is a significant predictive factor for poor short-term clinical outcomes of SARS-CoV-2 BA.2.2 patients.

Objective: The aim of the present study is to assess the utility of C-reactive protein to Lymphocyte Ratio (CLR) in predicting short-term clinical outcomes of patients infected by SARS-CoV-2 BA.2.2. Methods: This retrospective study was performed on 1,219 patients with laboratory-confirmed SARS-CoV-2 BA.2.2 to determine the association of CLR with short-term clinical outcomes. Independent Chi square test, Rank sum test, and binary logistic regression analysis were performed to calculate mean differences and adjusted odds ratios (aORs) with their 95% CI, respectively. Results: Over 8% of patients admitted due to SARS-CoV-2 BA.2.2. were critically ill. The best cut-off value of CLR was 21.25 in the ROC with a sensitivity of 72.3% and a specificity of 86%. After adjusting age, gender, and comorbidities, binary logistic regression analysis showed that elevated CLR was an independent risk factor for poor short-term clinical outcomes of COVID-19 patients. Conclusion: C-reactive protein to Lymphocyte Ratio is a significant predictive factor for poor short-term clinical outcomes of SARS-CoV-2 BA.2.2 inflicted patients.

One stage reconstruction of mid-face fistulous defects after maxillary sinus carcinoma resection with chimeric perforator free flaps.

BACKGROUND: The reconstruction of large fistulous defects following the radical ablation of maxillary sinus carcinoma remains challenging. The procedure requires not only the coverage of both intra-nasal lining and cheek skin but also sufficient obliteration of dead space between the two surfaces. In this report, we present our experience on the reconstruction of through-and-through defects in the mid-face with poly-foliated chimeric perforator flaps. METHODS: Nine patients (five males and four females) who received a two-skin paddled and one muscle segment chimeric perforator flap reconstruction after maxillary sinus carcinoma ablation between March 2015 and December 2019 were retrospectively reviewed in authors' hospital. The mean age of the patients was 59.11. Six patients were diagnosed as squamous cell carcinoma, two as adenoid cystic carcinoma, and one as adenocarcinoma. Brown class IIIa defects were found in eight patients, and one patient had a Brown class IVa defect. The mean size of intra-nasal defect was 5.67 × 4.06 cm2 , and the mean size of facial skin defect was 8.94 × 6.56 cm2 . ALT flaps were used in five patients, LD flaps in four patients. The minor skin paddle was firstly inset to the mucosal defect site as the lining. Then, the muscle segment was inset to eliminate the dead cavity. Finally, the major skin paddle was inset to recover the cutaneous defect. RESULTS: In ALT group, the mean size of the minor skin paddle was 5.7 × 4.7 cm2 , and the mean size of the major skin paddle was 8.7 × 6.6 cm2 . In LD group, the mean size of the minor skin paddle was 6.88 × 4.38 cm2 , and the mean size of the major skin paddle was 11 × 7.75 cm2 .All donor sites were closed primarily. All flaps survived and no partial flap loss was encountered. The mean follow-up time was 14.67 months, and there were no major postoperative complications. CONCLUSION: The use of poly-foliated chimeric perforator free flaps can provide functional and aesthetic coverage for extensive through-and-through mid-face defects without significant donor-site morbidities.

Characteristics of changes in volatile organic compounds and microbial communities during the storage of pickles.

The variations of volatile organic compounds (VOCs) and microbial communities of three pickles during storage at 4°C for one week were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), high-throughput sequencing, and Spearman correlation analysis. A total of 50 VOCs were identified from three pickles. During storage, most alcohols, aldehydes, ketones, and esters decreased, while acids increased, and sulfides, alkenes, and phenols were relatively equal. Firmicutes, Cyanobacteria, and Proteobacteria were the predominant bacterial phyla, and Weissella, Streptophyta, Leuconostoc, Bacillariophyta, and Lactobacillus were the predominant bacterial genera in three pickles. The bacterial diversity level significantly decreased during storage (P < 0.05). Spearman correlation coefficient indicated that Leuconostoc, Lactobacillus, and Weissella were highly correlated with the flavor of pickles, while Bacillariophyta and Streptophyta were highly correlated with the flavor formation of pickles during storage. These results could contribute to a better understanding of the impact of bacteria in flavor formation during pickle storage.

Tension-reduced closure of large abdominal wall defect caused by shotgun wound: A case report.

BACKGROUND: Large abdominal wall defect (LAWD) caused by shotgun wound is rarely reported. CASE SUMMARY: Herein, we describe a case of LAWD caused by a gunshot wound in which the abdominal wall was reconstructed in stages, including debridement, tension-reduced closure (TRC), and reconstruction with mesh and a free musculocutaneous flap. During a 3-year follow-up, the patient recovered well without hernia or other problems. CONCLUSION: TRC is a practical approach for the temporary closure of LAWD, particularly in cases when one-stage abdominal wall restoration is unfeasible due to significant comorbidities.

Lipid nanoparticle-encapsulated VEGFa siRNA facilitates cartilage formation by suppressing angiogenesis.

Cartilage is an important tissue that is widely found in joints, ears, nose and other organs. The limited capacity to regenerate makes cartilage reconstruction an urgent clinical demand. Due to the avascular nature of cartilage, we hypothesized that inhibition of vascularization contributes to cartilage formation. Here, we used VEGFa siRNA to inhibit the infiltration of the local vascular system. Optimized lipid nanoparticles were prepared by microfluidics for the delivery of siRNA. Then, we constructed a tissue engineering scaffold. Both seed cells and VEGFa siRNA-LNPs were loaded in a GELMA hydrogel. Subcutaneous implantation experiments in nude mice indicate that this is a promising strategy for cartilage reconstruction. The regenerated cartilage was superior, with significant upregulation of SOX9, COL-II and ACAN. This is attributed to an environment deficient in oxygen and nutrients, which facilitates cartilage formation by upregulating HIF-1α and FOXO transcription factors. In conclusion, a GelMA/Cells+VEGFa siRNA-LNPs scaffold was constructed to achieve superior cartilage regeneration.

[Application of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction in treatment of head titanium mesh exposure with soft tissue infection].

Objective: To explore the effectiveness of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction in the treatment of head titanium mesh exposure complicated with soft tissue infection. Methods: Between January 2015 and December 2021, 13 patients with head titanium mesh exposure complicated with soft tissue infection were admitted. There were 9 males and 4 females with a mean age of 42.9 years (range, 23-64 years). The duration of titanium mesh exposure was 22-609 days (median, 102 days). The wound site located at the frontal part in 3 cases, the parietal part in 1 case, the occipital part in 2 cases, the frontal-parietal part in 1 case, the temporal-parietal part in 4 cases, and the frontotemporal part in 2 cases. The titanium mesh had been taken out in 5 patients before admission, leaving skull defect and shape collapse, with signs of infection. The bacterial culture was positive in 7 cases and negative in 6 cases. The imaging examination revealed that the size of the skull defect ranged from 6 cm×5 cm to 21 cm×17 cm and the scalp defect ranged from 1 cm×1 cm to 15 cm×10 cm. The soft tissue infection did not reach dura in 5 cases, reached dura in 6 cases, and reached frontal sinus in 2 cases. The two-stage surgical protocol was used in all patients. In the first-stage operation, the latissimus dorsi myocutaneous flap was designed to repair the skull and scalp defects after removing the titanium mesh and thorough debridement. The size of muscle flap ranged from 13.5 cm×4.0 cm to 21.0 cm×17.0 cm, and the skin flap ranged from 7.0 cm×4.0 cm to 15.0 cm×10.0 cm. After the flap survived and stabilized, the second-stage operation was performed. The titanium mesh was implanted to reconstruct the skull contour. The size of titanium mesh ranged from 7.0 cm×6.0 cm to 21.5 cm×17.5 cm. The interval between the first- and second-stage operations was 3.7-17.8 months, with an average of 11.4 months. The survival of the skin flap, the appearance of the head, and the presence of re-exposed titanium mesh and infection were observed after operation. Results: At the first-stage operation, venous embolism occurred in 1 case, and no obvious abnormality was observed after treatment. All the flaps survived and the incisions healed by first intention. Besides, the incisions of the second-stage operation healed by first intention. All patients were followed up 1-96 months (median, 14 months). During follow-up, no exposure to titanium mesh, infection, or other complications occurred. The appearance satisfaction rate of the patients was 92.31% (11/13). There was no significant difference in the skull contour between the affected side and the healthy side in all patients. Conclusion: For the head titanium mesh exposure with soft tissue infection, the application of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction can reduce the risks of implant exposure and infection again by increasing the thickness of the scalp and blood supply, filling the wound cavity, and obtain good effectiveness.

Human antigen R promotes angiogenesis of endothelial cells cultured with adipose stem cells derived exosomes via overexpression of vascular endothelial growth factor in vitro.

Recent studies showed that exosomes obtained from adipose-derived stem cells (ADSCs) could improve the angiogenesis of fat grafts via overexpression of vascular endothelial growth factor (VEGF). Human antigen R (HuR) promotes the expression of VEGF in many cancers, but the effect of HuR in normal endothelial cells in the presence of ADSC-derived exosomes remains unclear. We aimed to investigate the effect of HuR on the expression of VEGF and angiogenesis of human umbilical vein endothelial cells (HUVECs) cultured with ADSCs-derived exosomes. The HuR-overexpressed HUVECs (HuR-HUVECs) were cocultured with ADSCs-derived exosomes. qRT-PCR and Western blotting were performed to examine the stability and expression of VEGF-A mRNA and protein. The proliferation, migration, and proangiogenic capacity of HuR-HUVECs were evaluated using cell counting kit-8 (CCK-8), scratch wound healing, and Matrigel tube formation assay. qRT-PCR showed that HuR-HUVECs had higher expression and slower attenuation of VEGF-A mRNA. Western blotting confirmed higher expression of VEGF-A in HuR-HUVECs. CCK-8, scratch wound healing, and Matrigel tube formation assay demonstrated an increased proangiogenic effect in HuR-HUVECs. HuR promotes angiogenesis of HUVECs cocultured with ADSCs-derived exosomes via stabilization and overexpression of VEGF in vitro. The HuR/VEGF pathway is an important regulatory mechanism of angiogenesis in endothelial cells.

The use of free myocutaneous flap and implant reinsertion for staged cranial reconstruction in patients with titanium mesh exposure and large skull defects with soft tissue infection after cranioplasty: Report of 19 cases.

BACKGROUND: Management of cranial defects following failed cranioplasty due to titanium mesh exposure and infection is challenging. The purpose of this report is to describe a modified technique using a free myocutaneous flap transfer for primary soft tissue reconstruction, and titanium mesh reinsertion for cranioplasty revision. METHODS: Nineteen patients with titanium mesh exposure and infection following cranioplasty were treated from January 2012 to January 2019. The average patient age was 41.89 years and the average size of the cranial defect was 7.74 × 13.92 cm. The reasons for craniotomy were craniocerebral trauma (n = 17), cerebrovascular disease (n = 1), and brain tumor (n = 1). The mean duration between implant exposure and current procedure was 7.16 months. Implant was removed and a free myocutaneous flap was designed to cover both scalp and cranium defects. After a mean duration of 12.32 months, implants were re-inserted in a vascularized pocket at the second stage by elevating a plane between the previously transferred fascia layer and muscle layer. RESULTS: The average sizes of the muscle flaps and skin paddles were 7.74 × 13.92 cm and 4.97 × 8.97 cm. The average size of the implants was 8.24 × 14.42 cm. All flaps survived completely with no complication. After an average follow-up of 48.16 months there were no cranioplasty failures. Functional coverage of craniectomy defect sites with normalized head contour was achieved. CONCLUSIONS: The use of free myocutaneous flap and implant reinsertion achieved durable cranial and scalp defect reconstruction and aesthetic outcomes. The myocutaneous flap increases blood supply to the scalp, which may reduce the chances of infection and implant re-exposure.

Treatment of Severe Postburn Contracture of the Elbow via Distraction With External Circular Frame in Pediatric Patient.

BACKGROUND: Although external circular frame (ECF) has been widely used for the correction of knee and ankle deformities, few studies reported the use of ECF for the treatment of severe postburn elbow contracture and stiffness (SPECS). The purpose of this retrospective study was to investigate the effectiveness and safety of the distraction using ECF in treating SPECS. METHODS: After institutional review board approval, we implemented a retrospective single-center case series study composed of consecutive patients treated for SPECS at Chinese PLA General Hospital between January 2010 and January 2018. After scar release and skin grafting, distraction with ECF was performed for 4 to 6 weeks, and the frame was retained for 2 more weeks before removal. Four weeks of splinting and at least 1 year of rehabilitation were recommended. Patient demographics, active and passive range of motion (ROM) of the elbow at different time points (preoperative, postdistraction, and final follow-up), and complications were collected from the electronic medical record. The primary outcome was the long-term improvement of the ROM. Other outcomes included complications and recurrence. RESULTS: The ECF was used to treat SPECS in 6 patients (3 males and 3 females, average age of 11.7 ± 2.6 years). Scar release and distraction with ECF significantly increased both active (from 3° preoperative to 38.7° postdistraction) and passive (from 3.5° preoperative to 48.3° postdistraction) ROM over an average distraction duration of 5.2 weeks. The long-term improvement of active and passive ROM was 38° ± 13.4° and 46° ± 14.7°, respectively, over a median follow-up of 4.1 years. Pin-tract infection occurred in 2 patients and were treated with local wound care and oral antibiotics. A tendon readhesion developed in 1 of the 6 patients because of noncompliance with splinting and physiotherapy, and was treated with revision surgery. CONCLUSIONS: The 3C strategy (i.e., contracture release, coverage of the defect with skin grafting, and correction of articular angle with gradual distraction using the ECF) is able to increase the ROM with minor complications. We recommend distraction with ECF as part of the treatment arsenal, particularly for severe contractures in which 1-stage correction is unfeasible because of considerable soft tissue shortening.

The novel GLP-1/GIP dual agonist DA3-CH is more effective than liraglutide in reducing endoplasmic reticulum stress in diabetic rats with cerebral ischemia-reperfusion injury.

BACKGROUND AND AIMS: Diabetes is one of the most important risk factors and comorbidities of ischemic stroke. Endoplasmic reticulum stress (ERS) is considered to be the major injury mechanism of ischemic stroke with diabetes. Studies have found that incretin can inhibit ERS in ischemia-reperfusion injury of the liver and heart. We aimed to explore the effects of GLP-1/GIP double agonist DA3-CH and GLP-1 single agonist liraglutide on ERS and apoptosis in diabetic rats with cerebral ischemia-reperfusion injury. METHODS AND RESULTS: 72 Sprague-Dawley (SD) male rats were randomly divided into 4 groups: ① blank group (Sham group, n = 18); model group (Saline group, n = 18); DA3 treatment group (DA3 group, n = 18); liraglutide treatment group (Lir group, n = 18). The Sham group was not given any treatment and was only raised in the same environment as the other groups. The remaining 3 groups used STZ-induced diabetes models. After the successful membrane formation of diabetes, DA3-CH and liraglutide (10 mmol/kg, once-daily for 14 days) were injected intraperitoneally. Thereafter, rats were subjected to middle cerebral artery occlusion followed by 24-h reperfusion. Animals were evaluated for neurologic deficit score, infarct volume, and biomarker analyses of the brain after ischemia. The DA3-CH-treated and liraglutide-treated groups showed significantly reduced scores of neurological dysfunction and cerebral infarction size, and reduced the expression of ERS markers GRP78, CHOP and Caspase-12, and the expression of apoptosis marker bax. Anti-apoptotic markers bcl-2 and neuronal numbers increased significantly. CONCLUSIONS: DA3-CH and liraglutide have obvious neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes, which can reduce the infarct size and the neurological deficit score. Their exert neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes by inhibiting endoplasmic reticulum stress and thereby reducing apoptosis. DA3 is better than liraglutide.

Is Decreased Local Bone Quality an Independent Risk Factor for Complications Following Fracture Fixation of Facial Bones.

PURPOSE: Although osteoporosis is associated with increased risks of complications of fracture fixation in the orthopedic literature, the association between local bone quality (LBQ) and complications of facial fracture fixation is unknown. The authors aim to identify that if decreased LBQ is an independent risk factor for complications following facial fracture fixation? METHODS: The authors conducted a prospective cohort study on patients over age of 50 years who underwent open reduction and rigid internal fixation for facial fractures. The primary predictor was LBQ (low or normal), decided by a combination of 3 panoramic indices. Other predictors included age, gender, body mass index (BMI), comorbidities, trauma-related characteristics, etc. The outcome variable was the presence of hardware-related, fracture-healing, wound, or neurosensory complications during 2-year follow-up. Univariate and multivariate regressions were performed to identify any significant association between predictor and outcome variables. RESULTS: The sample was composed of 69 patients (27 females) with an average age of 58.6 ±â€Š8.6 years and BMI of 25 ±â€Š3.8. Low-LBQ patients were significantly older, more females, had lower BMI, mainly injured from falls, had more complications compared to their normal-LBQ counterparts. However, multivariable logistic regressions demonstrated that only age (adjusted OR: 1.12, P = 0.031, 95% CI: 1.01, 1.23) and diabetes (adjusted OR: 12.63, P = 0.029, 95% CI: 1.3, 122.53) were significantly associated with overall complications after confounding adjustment. CONCLUSIONS: The results of the present study indicate that reduced LBQ is not an independent risk factor for complications following facial fracture fixation. The increased risk of complications in low-LBQ patients is more likely to be attributed to other age-related comorbidities such as diabetes. Therefore, the authors recommend detailed workup and good control of comorbidities in elderly trauma patient.

Human decellularized adipose matrix derived hydrogel assists mesenchymal stem cells delivery and accelerates chronic wound healing.

Biological scaffolds based stem cell delivery methods have emerged as a promising approach for tissue repair and regeneration. Here we developed a hydrogel biological scaffold from human decellularized adipose matrix (hDAM) for human adipose-derived stem cells (hASCs) delivery to accelerate chronic wound healing. The hDAM hydrogel was prepared by pepsin mediated digestion and pH controlled neutralization. The morphology, survival, proliferation, and angiogenic paracrine activity of hASCs cultured in the hydrogel were assessed. Moreover, the therapeutic efficacy of the hASCs-hydrogel composite for impaired wound healing was evaluated by using a full-thickness wound model on diabetic mouse. The developed hDAM hydrogel was a thermosensitive hydrogel, presented the biochemical complexity of native extracellular matrix and formed a porous nanofiber structure after gelation. The hydrogel can support hASCs adhesion, survival, and proliferation. Compared to standard culture condition, hASCs cultured in the hydrogel exhibited enhanced paracrine activity with increased secretion of hepatocyte growth factor. In the diabetic mice model with excisional full-thickness skin wounds, mice treated with the hASCs-hydrogel composite displayed accelerated wound closure and increased neovascularization. Our results suggested that the developed hDAM hydrogel can provide a favorable microenvironment for hASCs with augmented regeneration potential to accelerate chronic wound healing.

Free Medial Plantar Flap Versus Free Dorsal Myocutaneous Flap for the Reconstruction of Traumatic Foot Sole Defects.

BACKGROUND: Trauma can cause large defects in the weight-bearing foot sole. The reconstruction of such defects poses a major challenge in providing a flap that is durable, sensate, and stable. The pedicled medial plantar flap has been commonly used for reconstructing heel and plantar forefoot defects; however, the ipsilateral instep region is usually compromised by trauma. The purpose of this article was to report the use of contralateral free medial plantar flaps for the coverage of weight-bearing plantar defects and to compare these with distant free flaps. METHODS: Between 2005 and 2019, 15 patients (10 men and 5 women) with weight-bearing foot plantar defects were treated with a contralateral medial plantar flap, 11 (7 men and 4 women) with either a latissimus dorsi flap or a scapular flap. The average age was 18.07 ± 10.14 years (range, 4-34 years) and 26.55 ± 13.05 years (range, 13-56 years), respectively. Surgery was performed as a primary or secondary reconstruction after a trauma by the same surgical team. RESULTS: The mean size of defects was 9.73 ± 3.55 × 6.43 ± 2.8 cm in the contralateral free medial plantar flap group and 17.14 ± 6.84 × 11.41 ± 4.29 cm in the free dorsal flap group. All flaps survived in both groups. In the instep flap group, the appearance was satisfactory, the flap was durable, and tactile sensation was preserved in all patients, and none required a revision procedure. Two patients experienced delayed union of the donor-site grafted skin. In the dorsal flap group, 5 patients complained of a partial necrosis or delayed union at the recipient site, and 9 developed recurrent ulcerations over the weight-\bearing area. Five patients achieved only partial sensation in the flap. CONCLUSIONS: The contralateral medial plantar flap provides superior appearance, duration, and sensation over distant muscle flaps, without recurrent ulcerations. However, dorsal myocutaneous flaps may be used as a substitute when the defects are beyond the maximum boundaries of the instep area or are combined with bone loss.