MicroRNA-451 from Human Umbilical Cord-Derived Mesenchymal Stem Cell Exosomes Inhibits Alveolar Macrophage Autophagy via Tuberous Sclerosis Complex 1/Mammalian Target of Rapamycin Pathway to Attenuate Burn-Induced Acute Lung Injury in Rats

Objective Our previous studies established that microRNA(miR)-451 from human umbilical cord mesenchymal stem cell-derived exosomes(hUC-MSC-Exos)alleviates acute lung injury(ALI).This study aims to elucidate the mechanisms by which miR-451 in hUC-MSC-Exos reduces ALI by modulating macrophage autophagy.Methods Exosomes were isolated from hUC-MSCs.Severe burn-induced ALI rat models were treated with hUC-MSC-Exos carrying the miR-451 inhibitor.Hematoxylin-eosin staining evaluated inflammatory injury.Enzyme-linked immunosorbnent assay measured lipopolysaccharide(LPS),tumor necrosis factor-α,and interleukin-1βlevels.qRT-PCR detected miR-451 and tuberous sclerosis complex 1(TSC1)expressions.The regulatory role of miR-451 on TSC1 was determined using a dual-luciferase reporter system.Western blotting determined TSC1 and proteins related to the mammalian target of rapamycin(mTOR)pathway and autophagy.Immunofluorescence analysis was conducted to examine exosomes phagocytosis in alveolar macrophages and autophagy level.Results hUC-MSC-Exos with miR-451 inhibitor reduced burn-induced ALI and promoted macrophage autophagy.MiR-451 could be transferred from hUC-MSCs to alveolar macrophages via exosomes and directly targeted TSC1.Inhibiting miR-451 in hUC-MSC-Exos elevated TSC1 expression and inactivated the mTOR pathway in alveolar macrophages.Silencing TSC1 activated mTOR signaling and inhibited autophagy,while TSC1 knockdown reversed the autophagy from the miR-451 inhibitor-induced.Conclusion miR-451 from hUC-MSC exosomes improves ALI by suppressing alveolar macrophage autophagy through modulation of the TSC1/mTOR pathway,providing a potential therapeutic strategy for ALI.

Regulatory effect and mechanisms of carbon monoxidereleasing molecule Ⅱ on hepatic energy metabolism in septic mice

AIM: To investigate the possible mechanisms of exogenous carbon monoxide-releasing molecule II (CORM-2) intervention on hepatic energy metabolism in experimental sepsis.

Potentially fatal electrolyte imbalance caused by severe hydrofluoric acid burns combined with inhalation injury: A case report

BACKGROUND Hydrofluoric acid(HF)is one of the most common causes of chemical burns.HF burns can cause wounds that deepen and progress aggressively.As a result,HF burns are often severe even if they involve a small area of the skin.Published cases of HF burns have mostly reported small HF burn areas.Few cases of HF inhalation injury have been reported to date.CASE SUMMARY A 24-year-old man suffered from extensive hydrofluoric acid burns covering 60%of the total body surface area(TBSA),including deep second degree burns on 47%and third degree burns on 13%of the TBSA,after he fell into a pickling pool containing 15%HF.Comprehensive treatments were carried out after the patient was admitted.Ventricular fibrillation occurred 9 times within the first 2 h,and the lowest serum Ca2+concentration was 0.192 mmol/L.A dose of calcium gluconate(37 g)was intravenously supplied during the first 24 h,and the total amount of calcium gluconate supplementation was 343 g.Extracorporeal membrane oxygenation(ECMO)was applied for 8 d to handle the acute respiratory distress syndrome(ARDS)induced by the HF inhalation injury.The patient was discharged after 99 d of comprehensive treatment,including skin grafting.CONCLUSION Extensive HF burns combined with an inhalation injury led to a potentially fatal electrolyte imbalance and ARDS.Adequate and timely calcium supplementation and ECMO application were the keys to successful treatment of the patient.

Skin nerve regeneration and burn wound healing following spinal nerve root incision

Burn wounds were produced on two sides on the backs of Wistar rats, in addition to denervation on one side. The skin neural regeneration at the injury site and burn wound healing were evaluated following spinal nerve root incision. No nerve regeneration was observed in the burn wound region post-denervation, and the degree of epithelization was significantly less than the control group. With increasing time, expression of type I collagen, which plays a supporting role, and collagen III, which exhibits elastJc propertJes, were sJgnificantly increased Jn the two groups, but the expression was less in the denervation group compared with the control group, and the wound healing was faster in the control group. The ratio of type I collagen to type III collagen was significantly lower in the denervation group compared with the control group. The ratio gradually decreased with prolonged time in the denervation group, but remained unchanged in the control group. However, the elasticity of the tissues in the denervation group was better than the control group. During burn wound healing, innervations can promote wound healing, but denervation can improve the quality of wound remodeling.

Transplantation of human induced pluripotent stem cell derived keratinocytes accelerates deep second-degree burn wound healing

BACKGROUND Current evidence shows that human induced pluripotent stem cells(hiPSCs)can effectively differentiate into keratinocytes(KCs),but its effect on skin burn healing has not been reported.AIM To observe the effects of hiPSCs-derived KCs transplantation on skin burn healing in mice and to preliminarily reveal the underlying mechanisms.METHODS An analysis of differentially expressed genes in burn wounds based on GEO datasets GSE140926,and GSE27186 was established.A differentiation medium containing retinoic acid and bone morphogenetic protein 4 was applied to induce hiPSCs to differentiate into KCs.The expression of KCs marker proteins was detected using immunofluorescence staining.A model of a C57BL/6 mouse with deep cutaneous second-degree burn was created,and then phosphate buffered saline(PBS),hiPSCs-KCs,or hiPSCs-KCs with knockdown of COL7A1 were injected around the wound surface.The wound healing,re-epithelialization,engraftment of hiPSCs-KCs into wounds,proinflammatory factor level,and the NF-κB pathway proteins were assessed by hematoxylin-eosin staining,carboxifluorescein diacetate succinimidyl ester(CFSE)fluorescence staining,enzyme linked immunosorbent assay,and Western blotting on days 3,7,and 14 after the injection,respectively.Moreover,the effects of COL7A1 knockdown on the proliferation and migration of hiPSCs-KCs were confirmed by immunohistochemistry,EdU,Transwell,and damage repair assays.RESULTS HiPSCs-KCs could express the hallmark proteins of KCs.COL7A1 was down-regulated in burn wound tissues and highly expressed in hiPSCs-KCs.Transplantation of hiPSCs-KCs into mice with burn wounds resulted in a significant decrease in wound area,an increase in wound re-epithelialization,a decrease in proinflammatory factors content,and an inhibition of NF-κB pathway activation compared to the PBS group.The in vitro assay showed that COL7A1 knockdown could rescue the inhibition of hiPSCs-KCs proliferation and migration,providing further evidence that COL7A1 speeds up burn wound healing by limiting cell proliferation and migration.CONCLUSION In deep,second-degree burn wounds,COL7A1 can promote KC proliferation and migration while also suppressing the inflammatory response.

Effects and mechanism of platelet-rich plasma on military drill injury: A review

Military drill injury is a significant part of military medical research.The increase of training intensity and changes in training methods lead to differences in injury types.The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients’life.Platelet-rich plasma(PRP),a platelet concentrate,is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment.It plays an important role in injury repair and rehabilitation.In this article,we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms,with a focus on plantar fasciitis,stress fractures and other common injuries,in order to provide basic support for military reserve.

Transcriptome analysis reveals tumor antigen and immune subtypes of melanoma

Purpose:To screen potential tumor antigens for melanoma vaccine development and identify different immune subtypes.Methods:Transcriptional data(HTSEQ-FPKM)and clinical information of a 472 Melanoma cohort GDC TCGA Melanoma(SKCM)were downloaded from the UCSC XENA website(http://xena.ucsc.edu/).Subsequently,transcriptome data and clinical information of 210 melanoma cohort GSE65904 were downloaded from Gene Expression Omnibus(GEO),a large global public database.All the transcriptome expression data matrices were log2 transformed for subsequent analysis.GEPIA,TIMER,and IMMPORT databases are also used for analysis.Cell function experiments were performed to validate the role of the IDO1 gene in melanoma cell line A375.Results:Our study provides potential tumor antigens for vaccine development in melanoma patients:GZMB,GBP4,CD79A,APOBEC3F,IDO1,JCHAIN,LAG3,PLA2G2D,XCL2.In addition,we divide melanoma patients into two immune subtypes that have significant differences in tumor immunity and may have different responses to vaccination.In view of the unclear role of IDO1 in melanoma,we selected IDO1 for cell assay validation.Cell function assay showed that IDO1 was significantly overexpressed in the melanoma A375 cell line.After IDO1 knockdown,the activity,invasion,migration and healing ability of A375 cell lines were significantly decreased.Conclusion:Our study could provide a reference for the development of vaccines for melanoma patients.

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.

Expanded Forehead Stepped Flaps for Delayed Three-Stage Repair of Midface Skin Lesions

Background The forehead flap is the best flap for nasal defect repair and nasal reconstruction.It is also an ideal option for repairing skin lesions in the midface(including the nasal area,inner area of the cheek,and upper lip of the perioral area).However,the traditional frontal myocutaneous flap is relatively bulky for repairing pure skin lesions.In addition,the original forehead flap is generally not sufficient to cover a large wound area.If a large forehead flap is removed,the donor site cannot be sutured in one stage.In this study,an expanded forehead stepped flap was used to overcome the shortcomings of the traditional frontal myocutaneous flap.Methods In stage one surgery,a rectangular expander(80–100 mL)was implanted on the side of the forehead.The expansion pot was built-in,and the excess expansion amount was 160–200 mL.After 4 weeks of rest,stage two operation was performed to remove the skin lesions in the midface.The pulsation point of the supratrochlear artery on one side was used as the pedicle,and the flap was designed diagonally to the upper region of the opposite side.The flap was designed according to the size and shape of the wound.The distal portion of the flap was separated in the superficial layer of the frontalis muscle,approximately 1.7 cm above the superior orbital edge,and cut into the submuscle.The flap pedicle was cut from the superficial layer of the periosteum to form a stepped flap.Then,the flap was rotated downward to repair the wound in the midface.Five weeks later,stage three of the operation which involved flap pedicle division,was performed.Results Expanded forehead stepped flaps were used in 12 cases with 6–36 months of follow-up.In all cases,the blood supply to the flaps was good,and their color,texture,and thickness matched well with those of the surrounding skin.All patients were satisfied with the outcome of the repair.Conclusion Expanded forehead stepped flaps present an ideal option for repairing wounds after large skin lesion resections in the midface since they have multiple edges from a reliable blood supply,easiness to transfer,and well-matched color,texture,and thickness to those of the surrounding skin of the face to no need for many auxiliary incisions.

Facile Surface Engineering of NiCo_(2)O_(4) to Boost Propane Oxidation Activity

Spinel oxide(NiCo_(2)O_(4))has demonstrated great potential to replace noble metal catalysts for the oxidation reaction of air pollutants.To further boost the oxidation ability of such catalysts,in this study,a facile surface-engineering strategy wherein NiCo_(2)O_(4) was treated with different alkali solvents was developed.The obtained catalyst(NiCo_(2)O_(4)-OH)showed a higher surface alkalinity and more surface defects compared to the pristine spinel oxide,including enhanced structural distortion as well as promoted oxygen vacancies.The propane oxidation ability of NiCo_(2)O_(4)-OH was greatly enhanced,with a propane conversion rate that was approximately 6.4 times higher than that of pristine NiCo_(2)O_(4) at a reaction temperature 193℃.This work sets a valuable paradigm for the surface modulation of spinel oxide via alkali treatment to ensure a high-performance oxidation catalyst.

Lateral circumflex femoral artery perforator flap for the reconstruction of head soft tissue defects:Cross-region venous anastomosis

Background:Owing to its unique characteristics,the lateral circumflex femoral artery perforator(LCFAP)flap is often preferred for repairing head wounds with exposed skulls.However,given the vascular distribution in the head,particularly the veins,can lead to postoperative complications such as venous congestion of the flap.The rates of vascular exploration and necrosis in these flaps are significantly higher than in other body regions.Therefore,it is crucial to identify a safe and effective method for venous anastomosis of free flaps in the head region.Methods:This retrospective case series study included 10 patients with large head soft tissue defects treated at the Burn and Plastic Surgery Department of the Affiliated Hospital of Zunyi Medical University from January 2020 to December 2022.The head defects were reconstructed using LCFAP flaps,with flap veins anastomosed to the external jugular vein in the neck,either directly or via a bridging technique.Results:Among the 10 adult patients with massive head wound defects,7(70%)were men.The patients’mean age was 53.0 years(48–59 years).The wound defects were caused by trauma in 6(60%)patients and by tumors in 4(40%)patients.Postoperatively,no significant complications occurred,and all LCFAP flap survived without necrosis.Conclusion:The descending branch of the LCFAP flap effectively repairs massive head wound defects.The venous anastomosis method for this flap is associated with a low incidence of venous complications and a high patency rate,making it a clinically valuable reference.

Advances in the Treatment of Bromhidrosis

Armpit odor is a common disease with genetic tendency in cosmetic surgery. The odor emitted by it often affects the quality of life and social communication of patients, leading to psychological disorders in patients and seriously jeopardizing their mental health. With the continuous development and progress of medicine, there are many ways to treat armpit odor at present, but there is still no perfect way to treat armpit odor. This article reviews the progress of treatment methods in recent years.

Click-hydrogel delivered aggregation-induced emissive nanovesicles for simultaneous remodeling and antibiosis of deep burn wounds

As a high-risk trauma,deep burns are always hindered in their repair process by decreased tissue regeneration capacity and persistent infections.In this study,we developed a simultaneous strategy for deep burn wounds treatment using functional nanovesicles with antibacterial and tissue remodeling properties,delivered via a click-chemistry hydrogel.An aggregation-induced emission photosensitizer of 4-(2-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)vinyl)-1-(2-hydroxyethyl)pyridin-1-ium bromide(THB)with excellent photodynamic properties was first prepared,and then combined with readily accessible adipose stem cells-derived nanovesicles to generate the THB functionalized nanovesicles(THB@ANVs).The THB@ANVs showed strong antibacterial activity against Gram-positive bacteria(up to 100%killing rate),and also beneficial effects on tissue remodeling,including promoting cell migration,cell proliferation,and regulating immunity.In addition,we prepared a click-hydrogel of carboxymethyl chitosan for effective delivery of THB@ANVs on wounds.This hydrogel could be injected to conform to the wound morphology while responding to the acidic microenvironment.In vivo evaluations of wound healing revealed that the THB@ANVs hydrogel dressing efficiently accelerated the healing of second-degree burn wounds by reducing bacterial growth,regulating inflammation,promoting early angiogenesis,and collagen deposition.This study provides a promising candidate of wound dressing with diverse functions for deep burn wound repair.

Fresh human amniotic membrane effectively promotes the repair of injured common peroneal nerve

Suture and autologous nerve transplantation are the primary therapeutic measures for completely severed nerves. However, imbalances in the microenvironment and adhesion of surrounding tissues can affect the quality of nerve regeneration and repair. Previous studies have shown that human amniotic membrane can promote the healing of a variety of tissues. In this study, the right common peroneal nerve underwent a 5-mm transection in rats. Epineural nerve repair was performed using 10/0 non-absorbable surgical suture. The repair site was wrapped with a two-layer amniotic membrane with α-cyanoacrylate rapid medical adhesive after suture. Hindlimb motor function was assessed using footprint analysis. Conduction velocity of the common peroneal nerve was calculated by neural electrical stimulation. The retrograde axoplasmic transport of the common peroneal nerve was observed using fast blue BB salt retrograde fluorescent staining. Hematoxylin- eosin staining was used to detect the pathological changes of the common peroneal nerve sputum. The mRNA expression of axon regeneration-related neurotrophic factors and inhibitors was measured using real-time polymerase chain reaction. The results showed that the amniotic membrane significantly improved the function of the injured nerve;the toe spread function rapidly recovered, the nerve conduction velocity was restored, and the number of fast blue BB salt particles were increased in the spinal cord. The amniotic membrane also increased the recovery rate of the tibialis anterior muscle and improved the tissue structure of the muscle. Meanwhile, mRNA expression of nerve growth factor, growth associated protein-43, collapsin response mediator protein-2, and brain-derived neurotrophic factor recovered to near-normal levels, while Lingo-1 mRNA expression decreased significantly in spinal cord tissues. mRNA expression of glial-derived neurotrophic factor did not change significantly. Changes in mRNA levels were more significant in amniotic-membrane-wrapping-treated rats compared with model and nerve sutured rats. These results demonstrate that fresh amniotic membrane wrapping can promote the functional recovery of sutured common peroneal nerve via regulation of expression levels of neurotrophic factors and inhibitors associated with axonal regeneration. The study was approved by the Committee on Animal Research and Ethics at the Affiliate Hospital of Zunyi Medical University, China (approval No. 112) on December 1, 2017.

Therapeutic effect of autologous concentrated growth factor on lower-extremity chronic refractory wounds:A case report

BACKGROUND Management of chronic refractory wounds is one of the toughest clinical challenges for surgeons.Because of poor blood supply,less tissue coverage,and easy exposure,the lower leg is a common site for chronic refractory wounds.The current therapeutic regimens often lead to prolonged hospital stay and higher healthcare costs.Concentrated growth factor(CGF)is a novel blood extract that contains various growth factors,platelets,and fibrins to promote wound healing process.However,there has been little research reported on the treatment of lower extremity wounds with CGF.CASE SUMMARY A 37-year-old man,without any past medical history,presented an ulcerated chronic wound on his right lower leg.The skin defect exhibited clear boundaries,with a size of 2.0 cm×3.5 cm.The depth of wound was up to the layer of deep fascia.Staphylococcus aureus was detected by bacterial culture.The final diagnosis was right lower extremity ulcers with infection.Cefathiamidine,silver sulfadiazine,and mupirocin cream were applied to control the infection.CGF gel was prepared from the patient’s blood sample,and was used to cover the wound after thorough debridement.The skin wound was successfully healed after three times of CGF treatment.CONCLUSION CGF displays an excellent wound healing promoting effect in patients with lowerextremity chronic refractory wounds.

rAAV/ABAD-DP-6His attenuates oxidative stressinduced injury of PC12 cells

Our previous studies have revealed that amyloidβ（Aβ）-binding alcohol dehydrogenase （ABAD） decoy peptide antagonizes Aβ42-induced neurotoxicity. However, whether it improves oxidative stress injury remains unclear. In this study, a recombinant adenovirus constitutively secreting and expressing Aβ-ABAD decoy peptide （rAAV/ABAD-DP-6His） was successfully constructed. Our results showed that rAAV/ABAD-DP-6His increased superoxide dismutase activity in hydro-gen peroxide-induced oxidative stress-mediated injury of PC12 cells. Moreover, rAAV/ABAD-DP-6His decreased malondialdehyde content, intracellular Ca2＋concentration, and the level of reactive oxygen species. rAAV/ABAD-DP-6His maintained the stability of the mitochondrial membrane potential. In addition, the ATP level remained constant, and apoptosis was reduced. Overall, the results indicate that rAAV/ABAD-DP-6His generates the fusion peptide, Aβ-ABAD decoy peptide, which effectively protects PC12 cells from oxidative stress injury induced by hy-drogen peroxide, thus exerting neuroprotective effects.

Simulated aeromedical evacuation exacerbates burn induced lung injury:targeting mitochondrial DNA for reversal

Background:Aeromedical evacuation of patients with burn trauma is an important transport method in times of peace and war,during which patients are exposed to prolonged periods of hypobaric hypoxia;however,the effects of such exposure on burn injuries,particularly on burn-induced lung injuries,are largely unexplored.This study aimed to determine the effects of hypobaric hypoxia on burn-induced lung injuries and to investigate the underlying mechanism using a rat burn model.Methods:A total of 40 male Wistar rats were randomly divided into four groups(10 in each group):sham burn(SB)group,burn in normoxia condition(BN)group,burn in hypoxia condition(BH)group,and burn in hypoxia condition with treatment intervention(BHD)group.Rats with 30%total body surface area burns were exposed to hypobaric hypoxia(2000 m altitude simulation)or normoxia conditions for 4 h.Deoxyribonuclease I(DNase I)was administered systemically as a treatment intervention.Systemic inflammatory mediator and mitochondrial deoxyribonucleic acid(mtDNA)levels were determined.A histopathological evaluation was performed and the acute lung injury(ALI)score was determined.Malonaldehyde(MDA)content,myeloperoxidase(MPO)activity,and the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3)inflammasome level were determined in lung tissues.Data among groups were compared using analysis of variance followed by Tukey’s test post hoc analysis.Results:Burns resulted in a remarkably higher level of systemic inflammatory cytokines and mtDNA release,which was further heightened by hypobaric hypoxia exposure(P<0.01).Moreover,hypobaric hypoxia exposure gave rise to increased NLRP3 inflammasome expression,MDA content,and MPO activity in the lung(P<0.05 or P<0.01).Burn-induced lung injuries were exacerbated,as shown by the histopathological evaluation and ALI score(P<0.01).Administration of DNase I markedly reduced mtDNA release and systemic inflammatory cytokine production.Furthermore,the NLRP3 inflammasome level in lung tissues was decreased and burn-induced lung injury was ameliorated(P<0.01).Conclusions:Our results suggested that simulated aeromedical evacuation further increased burn-induced mtDNA release and exacerbated burn-induced inflammation and lung injury.DNase I reduced the release of mtDNA,limited mtDNA-induced systemic inflammation,and ameliorated burn-induced ALI.The intervening mtDNA level is thus a potential target to protect from burn-induced lung injury during aeromedical conditions and provides safer air evacuations for severely burned patients.

Effects of Blast Wave-induced Biomechanical Changes on Lung Injury in Rats

Objective To observe the dynamic impacts of shock waves on the severity of lung injury in rats with different injury distances.Methods Simulate open-field shock waves;detect the biomechanical effects of explosion sources at distances of 40,44,and 48 cm from rats;and examine the changes in the gross anatomy of the lungs,lung wet/dry weight ratio,hemoglobin concentration,blood gas analysis,and pathology.Results Biomechanical parameters such as the overpressure peak and impulse were gradually attenuated with an increase in the injury distance.The lung tissue hemorrhage,edema,oxygenation index,and pathology changed more significantly for the 40 cm group than for the 44 and 48 cm groups.The overpressure peak and impulse were significantly higher for the 40 cm group than for the 44 and 48 cm groups(P<0.05 or P<0.01).The animal mortality was significantly higher for the 40 cm group than for the other two groups(41.2%vs.17.8%and 10.0%,P<0.05).The healing time of injured lung tissues for the 40 cm group was longer than those for the 44 and 48 cm groups.Conclusions The effects of simulated open-field shock waves on the severity of lung injuries in rats were correlated with the injury distances,the peak overpressure,and the overpressure impulse.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

The apoptosis in various stages of infantile hemangioma

Objective: To detect the apoptosis in various stages of infantile hemangioma. Methods:Total 52 samples of infantile hemangioma (including 8 fresh samples) were included in this study. Agarose gel electrophoresis, transmission electron microscopy(TEM) and in situ TdT mediated dUTP-biotin nick end labeling(TUNEL) staining were used to observe the apoptosis. H-E staining was used to analyze the number of cells,the number and area of microvessels in hemangiomas. Results: The typical “ladder” occurred in the DNA electrophoresis of the hemangioma tissue in the late proferating stage. Many apoptotic cells were found in infantile hemangiomas with TEM. TUNEL staining identified that there were apoptotic cells througout the pathologic evolution of infantile hemangioma and the AI(%) was the highest in the late proferating stage. There existed close relationship between the AI(%) and the total number of cells in hemangioma. Conclusion: The decrease of cells resulted from the apoptosis may be the major cause of the spontaneous involution of infantile hemangioma.