A Polyvinyl Alcohol/Acrylamide Hydrogel with Enhanced Mechanical Properties Promotes Full-Thickness Skin Defect Healing by Regulating Immunomodulation and Angiogenesis Through Paracrine Secretion

Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and natural skin are substantially different.Here,we developed a polyvinyl alcohol(PVA)/acrylamide based interpenetrating network(IPN)hydrogel that was surface modified with polydopamine(PDA)and termed Dopa-gel.The Dopa-gel exhibited mechanical properties similar to native skin tissue and a superior ability to modulate paracrine functions.Furthermore,a tough scaffold with tensile resistance was fabricated using this hydrogel by three-dimensional printing.The results showed that the interpenetration of PVA,alginate,and polyacrylamide networks notably enhanced the mechanical properties of the hydrogel.Surface modification with PDA endowed the hydrogels with increased secretion of immunomodulatory and proangiogenic factors.In an in vivo model,Dopa-gel treatment accelerated wound closure,increased vascularization,and promoted a shift in macrophages from a proinflammatory M1 phenotype to a prohealing and anti-inflammatory M2 phenotype within the wound area.Mechanistically,the focal adhesion kinase(FAK)/extracellular signal-related kinase(ERK)signaling pathway may mediate the promotion of skin defect healing by increasing paracrine secretion via the Dopa-gel.Additionally,proangiogenic factors can be induced through Rho-associated kinase-2(ROCK-2)/vascular endothelial growth factor(VEGF)-mediated paracrine secretion under tensile stress conditions.Taken together,these findings suggest that the multifunctional Dopa-gel,which has good mechanical properties similar to those of native skin tissue and enhanced immunomodulatory and angiogenic properties,is a promising scaffold for skin tissue regeneration.

Oxygen Penetration Through Full-Thickness Skin by Oxygen-Releasing Sutures for Skin Graft Transplantation

The transplantation of full-thickness skin grafts(FTSGs)is important for reconstructing skin barrier and promoting wound healing.Sufficient oxygen supply is closely related to the success of skin grafting.However,full-thickness oxygen delivery is limited by the poor oxygen permeability of skin.Oxygen-releasing sutures(O_(2)sutures)were developed to facilitate oxygen penetration through full-thickness skin.The O_(2)sutures delivered 100 times more oxygen than topical gaseous oxygen therapy at a 15 mm depth in the skin model.Under extreme hypoxia(<0.5%O_(2),v/v),O_(2)sutures could also promote endothelial cell proliferation.After the transplantation of FTSGs in mice,O_(2)sutures accelerated blood re-perfusion and increased the survival area of the skin graft.It is expected that O_(2)sutures will be adopted in clinical applications to increase the success rate of full-thickness skin transplantation.

Effects of hyperbaric oxygen therapy on 32 cases of full-thickness skin grafting for the repair of defects on the hand and foot

Full-thickness skin grafting is one of the most commonly used repair methods for skin defects. It has the advantage of wear-resistant with less scar hyperplasia and less difficult to operate with no symptoms. Hyperbaric oxygen was used in this study after full-thickness skin grafting from September 2012 to August 2016 to achieve the best effect of skin survival after surgery.

One-step approach for full-thickness skin defect reconstruction in rats using minced split-thickness skin grafts with Pelnac overlay

Background:Split-thickness skin grafting is the current gold standard for the treatment of traumatic skin loss.However,for patients with extensive burns,split-thickness skin grafting is limited by donor skin availability.Grafting split-thickness skin minced into micrografts increases the expansion ratio but may reduce wound repair quality.Dermal substitutes such as Pelnac can enhance the healing of full-thickness skin wounds,but their application currently requires two surgeries.The present study investigated whether it is possible to repair full-thickness skin defects and improve wound healing quality in a single surgery using Pelnac as an overlay of minced split-thickness skin grafts in a rat model.Methods:A full-thickness skin defect model was established using male Sprague-Dawley rats of 10 weeks old.The animals were randomly divided into control and experimental groups in which Vaseline gauze and Pelnac,respectively,were overlaid on minced split-thickness skin grafts to repair the defects.Wound healing rate and quality were compared between the two groups.For better illustration of the quality of wound healing,some results were compared with those obtained for normal skin of rats.Results:We found that using Pelnac as an overlay for minced split-thickness skin grafts accelerated wound closure and stimulated cell proliferation and tissue angiogenesis.In addition,this approach enhanced collagen synthesis and increased the formation of basement membrane and dermis as well as the expression of growth factors related to wound healing while reducing scar formation.Conclusions:Using minced split-thickness skin grafts overlaid with Pelnac enables the reconstruction of fullthickness skin defects in a single step and can increase the healing rate while improving the quality of wound healing.

Double-nylon purse-string suture technique: Another addition to the endoscopist's toolbox for full-thickness defect closure

Iatrogenic perforation is the most feared adverse event in endoscopy.With the expansion of interventional endoscopy in favor of traditional surgery,it is now more crucial than ever to develop effective defect closure techniques.This has culminated in the dissemination of multiple novel closure technologies,including through-the-scope clips,over-the-scope clips,through-the-scope suturing and over-the-scope suturing devices.In this editorial,we comment on the recent publication by Wang and colleagues discussing the performance of the double-nylon purse-string suture technique in the closure of large(>3 cm)gastric full-thickness defects.This technique offers a promising,practical and cost-effective approach to closure of large full-thickness defects that can be readily imple-mented across diverse healthcare settings.

Use of autologous tissue engineered skin to treat porcine full-thickness skin defects

Objective. To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques. Methods： The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid （PGA）. Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks. Results. The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemicai methods. Conclusions ： By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.

Effect of endoscopic full-thickness resection assisted by distal serosal turnover with floss traction for gastric submucosal masses

BACKGROUND Complex and high-risk surgical complications pose pressing challenges in the clinical implementation and advancement of endoscopic full-thickness resection(EFTR).Successful perforation repair under endoscopy,thereby avoiding surgical intervention and postoperative complications such as peritonitis,are pivotal for effective EFTR.AIM To investigate the effectiveness and safety of EFTR assisted by distal serosal inversion under floss traction in gastric submucosal tumors.METHODS A retrospective analysis of patients with gastric and duodenal submucosal tumors treated with EFTR assisted by the distal serosa inversion under dental floss traction from January 2023 to January 2024 was conducted.The total operation time,tumor dissection time,wound closure time,intraoperative bleeding volume,length of hospital stay and incidence of complications were analyzed.RESULTS There were 93 patients,aged 55.1±12.1 years.Complete tumor resection was achieved in all cases,resulting in a 100% success rate.The average total operation time was 67.4±27.0 min,with tumor dissection taking 43.6±20.4 min.Wound closure times varied,with gastric body closure time of 24.5±14.1 min and gastric fundus closure time of 16.6±8.7 min,showing a significant difference(P<0.05).Intraoperative blood loss was 2.3±4.0 mL,and average length of hospital stay was 5.7±1.9 d.There was no secondary perforation after suturing in all cases.The incidence of delayed bleeding was 2.2%,and the incidence of abdominal infection was 3.2%.No patient required other surgical intervention during and after the operation.CONCLUSION Distal serosal inversion under dental-floss-assisted EFTR significantly reduced wound closure time and intraoperative blood loss,making it a viable approach for gastric submucosal tumors.

Postoperative encapsulated hemoperitoneum in a patient with gastric stromal tumor treated by exposed endoscopic full-thickness resection: A case report

BACKGROUND Gastric stromal tumors,originating from mesenchymal tissues,are one of the most common tumors of the digestive tract.For stromal tumors originating from the muscularis propria,compared with conventional endoscopic submucosal dissection(ESD),endoscopic full-thickness resection(EFTR)can remove deep lesions and digestive tract wall tumors completely.However,this technique has major limitations such as perforation,postoperative bleeding,and post-polypectomy syndrome.Herein,we report a case of postoperative serous surface bleeding which formed an encapsulated hemoperitoneum in a patient with gastric stromal tumor that was treated with exposed EFTR.Feasible treatment options to address this complication are described.CASE SUMMARY A 47-year-old male patient had a hemispherical protrusion found during gastric endoscopic ultrasonography,located at the upper gastric curvature adjacent to the stomach fundus,with a smooth surface mucosa and poor mobility.The lesion was 19.3 mm×16.1 mm in size and originated from the fourth ultrasound layer.Computed tomography(CT)revealed no significant evidence of lymph node enlargement or distant metastasis.Using conventional ESD technology for mucosal pre-resection,exposed EFTR was performed to resect the intact tumor in order to achieve a definitive histopathological diagnosis.Based on its morphology and immunohistochemical expression of CD117 and DOG-1,the lesion was proven to be consistent with a gastric stromal tumor.Six days after exposed EFTR,CT showed a large amount of encapsulated fluid and gas accumulation around the stomach.In addition,gastroscopy suggested intracavitary bleeding and abdominal puncture drainage indicated serosal bleeding.Based on these findings,the patient was diagnosed with serosal bleeding resulting in encapsulated abdominal hemorrhage after exposed EFTR for a gastric stromal tumor.The patient received combined treatments,such as hemostasis under gastroscopy,gastrointestinal decompression,and abdominal drainage.All examinations were normal within six months of follow-up.CONCLUSION This patient developed serous surface bleeding in the gastric cavity following exposed EFTR.Serosal bleeding resulting in an encapsulated hemoperitoneum is rare in clinical practice.The combined treatment may replace certain surgical techniques.

A CS-based composite scaffold with excellent photothermal effect and its application in full-thickness skin wound healing

The development of natural polymer-based scaffolds with excellent biocompatibility,antibacterial activity,and blood compatibility,able to facilitate full-thickness skin wound healing,remains challenging.In this study,we have developed three chitosan(CS)-based porous scaffolds,including CS,CS/CNT(carbon nanotubes)and CS/CNT/HA(nano-hydroxyapatite,n-HA)using a freeze-drying method.All three scaffolds have a high swelling ratio,excellent antibacterial activity,outstanding cytocompatibility and blood compatibility in vitro.The introduction of CNTs exhibited an obvious increase in mechanical properties and exerts excellent photothermal response,which displays excellent healing performance as a wound dressing in mouse full-thickness skin wound model when compared to CS scaffolds.CS/CNT/HA composite scaffolds present the strongest ability to promote full-thickness cutaneous wound closure and skin regeneration,which might be ascribed to the synergistic effect of photothermal response from CNT and excellent bioactivity from n-HA.Overall,the present study indicated that CNT and n-HA can be engineered as effective constituents in wound dressings to facilitate full-thickness skin regeneration.

Betaine combined with traditional Chinese medicine ointment to treat skin wounds in microbially infected diabetic mice

BACKGROUND Skin wounds are highly common in diabetic patients,and with increasing types of pathogenic bacteria and antibiotic resistance,wounds and infections in diabetic patients are difficult to treat and heal.AIM To explore the effects of betaine ointment(BO)in promoting the healing of skin wounds and reducing the inflammation and apoptosis of skin cells in microbially infected diabetic mice.METHODS By detecting the minimum inhibitory concentrations(MICs)of betaine and plant monomer components such as psoralen,we prepared BO with betaine as the main ingredient,blended it with traditional Chinese medicines such as gromwell root and psoralen,and evaluated its antibacterial effects and safety in vitro and in vivo.The skin infection wound models of ordinary mice and diabetic mice were constructed,and the OTC drugs mupirocin ointment and Zicao ointment were used as controls to evaluate the antibacterial effects in vivo and the anti-inflammatory and anti-apoptotic effects of BO.RESULTS The MICs of betaine against microorganisms such as Staphylococcus aureus(S.aureus),Candida albicans and Cryptococcus neoformans ranged from 4 to 32μg/mL.Gromwell root and psoralea,both of which contain antimicrobial components,mixed to prepare BO with MICs ranging from 16 to 64μg/mL,which is 32-256 times lower than those of Zicao ointment,although the MIC is greater than that of betaine.After 15 days of treatment with BO for USA300-infected ordinary mice,the wound scab removal rates were 83.3%,while those of mupirocin ointment and Zicao ointment were 66.7%and 0%,respectively,and the differences were statistically significant.In diabetic mice,the wound scab removal rate of BO and mupirolacin ointment was 80.0%,but BO reduced wound inflammation and the apoptosis of skin cells and facilitated wound healing.CONCLUSION The ointment prepared by mixing betaine and traditional Chinese medicine can effectively inhibit common skin microorganisms and has a strong effect on the skin wounds of sensitive or drug-resistant S.aureus-infected ordinary mice and diabetic mice.

A STUDY OF mRNA EXPRESSION OF GROWTH FACTORS IN FULL-THICKNESS BURNT RATS AFTER INTERMINGLEDTRANSPLANTATION OF AUTO-ALLOGRAFT SKIN

Objective To scrutinize the effect of growth factors resulting from the intermingled skin graft onwound healing. Methods By means of RT-PCR technique, mRNA expressions of TGFα, TGFβ1, PDGF andbFGF of autografts and allografts on burnt rats were quantitatively analysed. Results (1) mRNA expressions ofall the four growth factors mentioned above were found both in allografts and autografts, the expressions beinghigher in autografts than allografts; (2) In autografts, TGFα expression began to rise from second post transplantday (D2), reaching a peak on D18,. TGFβ1 expression gained a high level on D2 and had itS peak on D18; PDGFexpression had its peak on D4, rebounding on D25; bFGF expression, exceedingly high on D2, dropped andrebounded in the same manner as in PDGF; (3) In the early stage of the wound healing, mRNA expression of thefour growth factors was lower in allografts, rising up in varying degrees thereafter. Conclusion (1) Graftsurvival took place both in autografts and allografts, with the former pederming better than the latter; (2) Thecombining action of growth factors that reached the affected area through autosecretion and bysecretion probablypromoted the healing of the burn wound, following signal transmission channels; (3) Rejection, which occurred inallogralts, was responsible for the decreasing viability of allografts and their replacement by the host skin.

Correction of Scar Contracture Deformity of Dorsal Hand by Invisible Full-thickness Mesh Skin Graft

Objective To investigate the effect of invisible full-thickness mesh skin graft in the treatment of scar contracture deformity of the dorsal hand.Methods From January 2016 to February 2019,25 patients with cicatricial contracture deformity of dorsal hand admitted to our hospital underwent full thickness skin graft.During the operation,the scar healed completely and the superficial fascia remained intact.The wound surface was transplanted with invisible mesh full thickness skin graft.The survival of the skin graft and the recovery of hand function and appearance in the later period were observed after the operation.Results The skin grafts of 20 patients survived with high quality,3 cases had partial epidermis exfoliation,and 2 cases had partial epidermis scattered in blisters.After intensive dressing change,all wounds healed and no complications occurred after the operation.The hand function and appearance of the patients were obviously improved.Conclusion The application of full thickness skin graft to correct scar deformity has the advantages of good functional and appearance recovery and difficult postoperative contracture.Invisible full-thickness mesh skin graft is one of the ideal methods to correct scar contracture deformity of the dorsal hand.

Acellular fish skin grafts in diabetic foot ulcer care:Advances and clinical insights

Diabetic foot ulcers(DFUs)represents a significant public health issue,with a rising global prevalence and severe potential complications including amputation.Traditional treatments often fall short due to various limitations such as high recurrence rates and extensive resource utilization.This editorial explores the innovative use of acellular fish skin grafts as a transformative approach in DFU management.Recent studies and a detailed case report highlight the efficacy of acellular fish skin grafts in accelerating wound closure,reducing dressing changes,and enhancing patient outcomes with a lower socio-economic burden.Despite their promise,challenges such as limited availability,patient acceptance,and the need for further research persist.Addressing these through more extensive randomized controlled trials and fostering a multidisciplinary treatment approach may optimize DFU care and reduce the global health burden associated with these complex wounds.

Endoscopic full-thickness resection: current status

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However,those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection(EFTR) is an evolving technique,which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Endoscopic full-thickness resection for gastric submucosal tumors arising from the muscularis propria layer

AIM: To evaluate the efficacy, safety and feasibility of endoscopic full-thickness resection (EFR) for the treatment of gastric submucosal tumors (SMTs) arising from the muscularis propria.

Full-thickness excision using transanal endoscopic microsurgery for treatment of rectal neuroendocrine tumors

AIM:To assess the efficacy of full-thickness excision using transanal endoscopic microsurgery(TEM) in the treatment of rectal neuroendocrine tumors.METHODS:We analyzed the data of all rectal neuroendocrine tumor patients who underwent local full-thickness excision using TEM between December 2006 and December 2014 at our department. Data collected included patient demographics,tumor characteristics,operative details,postoperative outcomes,pathologic findings,and follow-ups. RESULTS:Full-thickness excision using TEM was performed as a primary excision(n = 38) or as complete surgery after incomplete resection by endoscopic polypectomy(n = 21). The mean size of a primary tumor was 0.96 ± 0.21 cm,and the mean distance of the tumor from the anal verge was 8.4 ± 1.4 cm. The mean duration of the operation was 57.6 ± 13.7 min,and the mean blood loss was 13.5 ± 6.6 m L. No minor morbidities,transient fecal incontinence,or wound dehiscence was found. Histopathologically,all tumors showed typical histology without lymphatic or vessel infiltration,and both deep and lateral surgical margins were completely free of tumors. Among 21 cases of complete surgery after endoscopic polypectomy,9 were histologically shown to have a residual tumor in the specimens obtained by TEM. No additional radical surgery was performed. Norecurrence was noted during the median of 3 years' follow-up.CONCLUSION:Full-thickness excision using TEM could be a first surgical option for complete removal of upper small rectal neuroendocrine tumors.

Endoscopic full-thickness resection and laparoscopic surgery for treatment of gastric stromal tumors

AIM: To assess the effectiveness of endoscopic full-thickness resection (EFR) and laparoscopic surgery in the treatment of gastric stromal tumors arising from the muscularis propria.

Closure techniques in exposed endoscopic full-thickness resection:Overview and future perspectives in the endoscopic suturing era

Exposed endoscopic full-thickness resection(EFTR)without laparoscopic assistance is a minimally invasive natural orifice transluminal endoscopic surgery technique that is emerging as a promising effective and safe alternative to surgery for the treatment of muscularis propria-originating gastric submucosal tumors.To date,various techniques have been used for the closure of the transmural postEFTR defect,mainly consisting in clip-and endoloop-assisted closure methods.However,the recent advent of dedicated tools capable of providing full-thickness defect suture could further improve the efficacy and safety of the exposed EFTR procedure.The aim of our review was to evaluate the efficacy and safety of the different closure methods adopted in gastric-exposed EFTR without laparoscopic assistance,also considering the recent advent of flexible endoscopic suturing.

Extensive full-thickness eyelid reconstruction with rotation flaps through "subcutaneous tunnel" and palatal mucosal grafts

· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved surgical technique in which the orbicularis oculi myocutaneous flap is rotated through a "subcutaneous tunnel" in conjunction with a palatal mucosal graft employed for lining.·METHODS: Data from 22 eyes with extensive full-thickness eyelid defects from various causes between2009 and 2013 were analyzed in this study. After the different layers of eyelid were separated completely, a temporally based orbicularis oculi myocutaneous flap was designed following fishtail lines and was mobilized,leaving the base of the pedicle intact with a submuscular tissue attachment. The flap was then rotated through a "subcutaneous tunnel" to the defect, and the donor site was closed primarily. Posterior lamellar reconstruction was performed with a mucosal graft harvested from the hard palate.·RESULTS: All the flaps were survived without any healing problems. There was no corneal irritation, flap contraction, or significant donor-site morbidity in the follow-up period. The incision scars were almost invisible.The defects were repaired completely, and the evaluations showed satisfactory function and appearance.·CONCLUSION: This technique is an improved singlestage operation and can be applied to repair large, full-thickness eyelid defects from various causes. With our method, the functional and aesthetic results can be obtained in either the upper or lower eyelids.

Endoscopic full-thickness resection for treating small tumors originating from the muscularis propria in the gastric fundus: An improvement in technique over 15 years

BACKGROUND The fundus of the stomach is regarded as a difficult area for endoscopic resection of small tumors originating from the muscularis propria(MP tumors).Three endoscopic resection techniques have been developed to treat these tumors,including ligation-assisted endoscopic full-thickness resection(L-EFTR),snareassisted EFTR(S-EFTR),and endoscopic submucosal dissection-assisted EFTR(EEFTR).To date,no studies have compared these techniques.AIM We aimed to evaluate and compare S-EFTR with L-EFTR and E-EFTR for treating small MP tumors in the gastric fundus.METHODS We retrospectively reviewed patients with primary small MP tumors in the gastric fundus and treated by these three techniques between January 2016 and December 2018 at Shengjing Hospital,China.Standard demographic and clinicopathologic data,including sex,age,tumor size,surgeon details,and pathological results,were collected.Data regarding operation duration,cost,enbloc resection,and severe complications were also extracted and compared.RESULTS A total of 36 patients(27 women)with a mean age of 55.8±10.20 years were included in this study.The mean tumor size was 9.0±3.98 mm.All the methods showed a 100%en-bloc resection rate and 0%severe complication rate.There was no statistically significant difference among the three groups in the operation duration(P=0.148).The cost comparison for the whole procedure was as follows:E-EFTR>L-EFTR>S-EFTR(5837.5±7212.96 CNY,5970.7±3465.27 CNY,5852.0±6438.25 CNY,respectively,P<0.001).CONCLUSION S-EFTR,L-EFT,and E-EFTR are all effective for resection of small MP tumors in the gastric fundus.S-EFTR is superior in terms of cost-effectiveness.