Application of mesenchymal stem cell therapy in kidney transplantation: a continued story / 器官移植

Immunosuppressant is one of the main preventive measures for rejection after organ transplantation, whereas it may reduce the host response capability to pathogens and increase the risk of infection. In recent years, the application of mesenchymal stem cell (MSC) therapy in the field of solid organ transplantation has attracted widespread attention. Preclinical studies have shown that MSC therapy may prolong the survival time of transplant kidney, induce immune tolerance, accelerate the repair of acute kidney injury and promote the recovery of renal function. Clinical trials have confirmed the safety, tolerance and effectiveness of MSC therapy. Consequently, general characteristics, immunomodulation and tissue repair function of MSC, and the application of MSC in clinical trials of kidney transplantation were reviewed, the unresolved issues were briefly discussed and the prospects for subsequent research were predicted, aiming to provide reference for promoting the application of MSC therapy in clinical kidney transplantation.

Preparation and Application of Polypyrrole Conductive Hydrogels in Biomedical Field / 分析化学

Hydrogel is a kind of material with high water content,good biocompatibility and extracellular matrix-like property,among which polypyrrole(PPy)conductive hydrogels have both physical characteristics and excellent conductivity of hydrogels themselves.Its conductivity can be used to detect electrical signals generated in biological systems and provide electrical stimulation to regulate the activities and functions of cells and tissues.These characteristics make it widely used in the biomedical field.The recent progress of PPy conductive hydrogels in biomedical field was reviewed in this paper.In terms of classification,according to the cross-linking mechanism of PPy and hydrogel matrix,the non-covalent cross-linked PPy conductive hydrogels and covalent cross-linked PPy conductive hydrogels were divided.The applications of PPy conductive hydrogels in the biomedical field(Skin damage repair,nerve repair,myocardial repair and flexible sensing,etc.)were mainly introduced,and the development trend and challenges of PPy conductive hydrogels in the biomedical field were discussed.

Influence of adipose tissue and its derivative on wound repair and vascularization / 中国组织工程研究

BACKGROUND:Vascularization is essential for wound healing and functional recovery during soft tissue repair.Adipose tissue is believed to be the body's largest source of stem cells,and a number of different fat complexes have been developed for research and treatment.Its ability to promote angiogenesis and soft tissue repair has been extensively studied. OBJECTIVE:To review the progress of vascularization in soft tissue repair,and to summarize the preparation methods of adipose tissue and its derivative and their applications in vascularization and soft tissue repair.It is proven that adipose tissue and its derivative have excellent research value and clinical application prospects in vascular and soft tissue engineering. METHODS:PubMed,Web of Science and CNKI databases were used to search the related articles published from January 2010 to February 2023.The search terms were"soft tissue repair,wound healing,vascularization,angiogenesis,adipose tissue,stromal vascular fraction,adipose tissue-derived microvascular fragment,nanofat,adipose extracellular matrix/stromal vascular fraction gel"in Chinese and English.A small number of old classic literature was also included.An initial screening was performed by reading the titles and abstracts to exclude literature that was not relevant to the topic of the article,and 69 papers were finally included for the analysis of the result. RESULTS AND CONCLUSION:(1)Wound healing is an important physiological process,which mainly occurs when tissue is damaged,such as injury,surgery,burn,tumor,infection and vascular disease caused by tissue damage and defects.(2)Adequate vascularization of the wound site is essential for tissue repair,reconstruction of local homeostasis and functional recovery.(3)Adipose tissue is believed to be the body's largest pool of stem cells and a number of different fat components have been used for research and treatment.(4)Due to its inherent composition and preparation advantages,adipose tissue will continue to play an important role in tissue engineering research and therapy.

Low-temperature condensation deposition method for 3D printing of bone tissue engineering poly-L-lactic acid/pearl powder composite scaffold / 中国组织工程研究

BACKGROUND:The repair of large-scale bone defects is still facing serious challenges.It is of great significance to develop personalized,low-cost,and osteogenic-inducing tissue engineering scaffolds for bone repair. OBJECTIVE:To explore the process of 3D printing bone tissue engineering scaffold containing pearl composite material by low-temperature condensation deposition method,and further test the physicochemical properties and in vitro biological functions of the composite scaffold. METHODS:Pearl powder was prepared by grinding and sieving.The pearl powder of different qualities was added into the poly-L-lactic acid ink,so that the mass ratio of pearl powder to poly-L-lactic acid was 0,0.1,0.2,0.3,and 0.5,respectively.The 3D-printed poly-L-lactic acid/pearl powder scaffolds were prepared using the low-temperature condensation deposition method.The microstructure,compressive properties,water contact angle,cytocompatibility,and in vitro bone differentiation ability of the printed poly-L-lactic acid/pearl powder composite scaffolds were detected. RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the five groups of scaffolds all had micropores with a diameter of 2 μm or even smaller,irregular shapes and interconnectivity.(2)All the five groups had good compressive properties.The compressive strength of the pearl powder 0.5 group was higher than that of the other four groups(P<0.05).The water contact angle of the pearl powder 0.2 group and the pearl powder 0.5 group was smaller than that of the pearl powder 0 group(P<0.01,P<0.001).(3)Bone marrow mesenchymal stem cells were co-cultured with five groups of scaffolds for 1,3,and 5 days,respectively.The cell proliferation in pearl powder 0.1,0.2,0.3,and 0.5 groups cultured for 3 and 5 days was faster than that in pearl powder 0 group(P<0.05).After 1 day of culture,live-dead staining exhibited that the number of cells on the scaffold was small,but all of them were living cells.(4)Bone marrow mesenchymal stem cells were inoculated on the scaffold surface of the pearl powder 0 group and pearl powder 0.1 group respectively for osteogenic differentiation.The alkaline phosphatase activity induced for 4 and 6 days in the pearl powder 0.1 group was higher than that in the pearl powder 0 group(P<0.05).(5)The results showed that the poly-L-lactic acid/pearl powder composite scaffold had good compressive strength,hydrophilicity,cytocompatibility,and osteogenic properties.

Functional characteristics and clinical applications of MXene nanoparticles in wound healing / 中国组织工程研究

BACKGROUND:MXene nanoparticles have considerable application prospects as effective functional components of skin wound dressings due to their unique properties of conductivity,hydrophilicity,antibacterial activity,and biocompatibility. OBJECTIVE:To review the synthesis methods,functional properties,and application of MXene nanoparticles in skin injury repair. METHODS:"MXene,nanoparticles,nanomaterials,bioactive nanoparticles","wound dressing,wound dressing,wound repair materials","wound repair,wound healing,wound surface"were used as Chinese search terms to search Wanfang and CNKI databases."MXene,nanoparticles,nano-materials,bioactive nanoparticles","wound dressing,wound healing material","wound healing,wound repair,wound"were used as English search terms to search the PubMed database.Finally,88 articles were included for review analysis. RESULTS AND CONCLUSION:(1)MXene synthesis can be divided into two methods:bottom-up synthesis and top-down synthesis.The synthesized MXene can be further modified to enhance biocompatibility for better application in biomedicine.(2)MXene has a series of excellent properties such as hydrophilicity,antibacterial,photothermal properties,electrical conductivity,and good biocompatibility,all of which make it the basis for excellent skin repair materials.(3)At present,many scholars have developed new composite materials for wound dressings.Currently,these composite materials are based on MXene nanomaterials and make full use of its excellent characteristics as mentioned above,which play a role in local skin wound sterilization,drug delivery,and sustained release,active regulation of cytokines,and can integrate the advantages of other biologically active agents.It plays a better role in wound healing,especially in the treatment of complex chronic wounds.(4)Various composite materials such as MXene@PVA hydrogel and MXene@CH sponge developed based on various properties of MXene have shown good effects on improving tissue repair performance and repairing skin damage as drug carriers.It shows that MXenes nanoparticles are in the initial stage of development and have great prospects in the field of promoting skin repair.The characteristics and surface modification of MXenes nanoparticles have been well studied,but the molecular mechanism of dose-dependent biotoxicity is relatively incomplete.

Potential and advantages of metal organic frameworks-based hydrogel materials for repairing soft and hard tissues / 中国组织工程研究

BACKGROUND:Due to the mechanical properties,unstable drug release,single function and other problems of pure hydrogel materials,in recent years,researchers have prepared a variety of metal organic frameworks-based hydrogel materials by introducing metal organic frameworks into hydrogel,and showed great potential in the field of soft and hard tissue regeneration. OBJECTIVE:To classify the metal organic frameworks-based hydrogel materials based on how metal organic frameworks enhance the properties of hydrogel and further summarize its recent research in the field of soft and hard tissue regeneration,in order to provide ideas and theoretical supports for the subsequent in-depth research on synthesis mechanism and clinical application of the composite material. METHODS:Using"metal organic frameworks,hydrogels,tissue engineering,tissue,bone regeneration,bone,wound"as English and Chinese search terms,we searched Web of Science,PubMed,CNKI,and Wanfang databases.The search period ranged from January 2000 to August 2023.By reading the titles and abstracts,the repetitive studies and unrelated literature of Chinese and English literature were excluded.After the literature quality evaluation,73 articles were included for review. RESULTS AND CONCLUSION:(1)Metal organic frameworks-based hydrogel materials effectively solve the problems of poor mechanical properties,unstable drug release and single function of pure hydrogel.(2)Metal organic frameworks enhance the capacity of repair and regeneration by strengthening the cross-linking of hydrogel,the drug delivery capacity of hydrogel and the multifunction of hydrogel.(3)In terms of hard tissue repair,it has shown good repair effects in animal models of diseases such as bone defects,osteoarthritis,and cartilage defects,suggesting potential application prospects in clinical repair.(4)In terms of soft tissue regeneration,it has the capacities of hemostasis,antibacterial,inflammatory state regulation,oxidative stress state regulation,promoting angiogenesis and other functions,effectively improving the microenvironment of various complex wounds and promoting soft tissue regeneration.(5)Although metal organic frameworks-based hydrogels have many excellent properties,they are still in the initial stage and there are some urgent problems to be solved in the process of clinical transformation,such as the cytotoxicity of metal organic frameworks and large-scale synthesis of metal organic frameworks.(6)With further research,metal organic frameworks-based hydrogels have broad application prospects in the field of soft and hard tissue repair.

Wound healing in diabetic mice with soluble microneedle-loaded platelet-rich plasma lysate: a preliminary study / 中国输血杂志

【Objective】 To prepare microneedles(MNs) loaded with platelet-rich plasma lysate (PL) using Carboxymethyl chitosan (CMCS), and explore the prospect of PL MNs in the treatment of diabetic wounds. 【Methods】 CMCS was used as the basic material, and an appropriate amount of polyvinylpyrrolidone (PVPK-60) was added to prepare needle materials of different concentrations, and the optimal concentration was determined by investigating the needle formation rate, morphological characteristics and mechanical properties, and the growth factor activity in PL MNs was investigated. The diabetic mice were randomly divided into four groups after the back wound was made, the control group did not do any treatment, the PL smear group was treated with PL smearing, the blank MNs group was treated with MNs without PL, and the PL MNs group was treated with PL microneedles. The effect of PL MNs in wound healing in diabetic mice was evaluated through body observation, H&E staining and immunohistochemistry results. 【Results】 When PVPK60 was 40 mg/mL, the needle formation rate was 100%, the array was complete, the needle body was full, and the needle was sharp. According to the results of mechanical-displacement curve and weight pressure change experiment, the prepared PL MNs have good mechanical strength. The results of growth factor analysis indicated that the content of vascular endothelial growth factor (VEGF) in PL was (625±35) pg/mL, and the content of platelet-derived growth factor-BB (PDGF-BB) was (18 741±1 287) pg/mL. After making the MNs, the VEGF content was (183±2) pg/mL, and the PDGF-BB content was (8049±1157) pg/mL. Although the concentration of growth factors decreased, growth factor activity was still preserved.The results of wound healing experiments in diabetic mice showed that the PL MNs group had better healing, and the wound healing rate was different from that of three groups (P<0.01). The results of H&E staining showed that the PL MNs group had fewer inflammatory cell infiltrates and bleeding spots. The number of fibroblasts and new microvascular in the control group was worse than that in the PL MNs group and the PL smear group. The results of immunohistochemistry indicated that the expression of pro-inflammatory factor IL-6 decreased, while anti-inflammatory factor TGF-β and angiogenesis index CD31 increased in the PL MNs group, which were significantly different from those in the other three groups (P<0.01). 【Conclusion】 The PL MNs prepared in this experiment have good mechanical properties, which has a positive effect on the wound healing of diabetic mice, and provides a new idea for diabetic wound healing.

Galectins in epithelial-mesenchymal transition: roles and mechanisms contributing to tissue repair, fibrosis and cancer metastasis

Galectins are soluble glycan-binding proteins that interact with a wide range of glycoproteins and glycolipids and modulate a broad spectrum of physiological and pathological processes. The expression and subcellular localization of different galectins vary among tissues and cell types and change during processes of tissue repair, fibrosis and cancer where epithelial cells loss differentiation while acquiring migratory mesenchymal phenotypes. The epithelial-mesenchymal transition (EMT) that occurs in the context of these processes can include modifications of glycosylation patterns of glycolipids and glycoproteins affecting their interactions with galectins. Moreover, overexpression of certain galectins has been involved in the development and different outcomes of EMT. This review focuses on the roles and mechanisms of Galectin-1 (Gal-1), Gal-3, Gal-4, Gal-7 and Gal-8, which have been involved in physiologic and pathogenic EMT contexts.

Fabrication of self-healing injectable hyaluronic acid hydrogel for promoting angiogenesis / 上海交通大学学报（医学版）

Objective·To construct a self-healing injectable hyaluronic acid(HA)-based hydrogel(HAPD-Cu)and investigate the effects of different copper ions on the properties of the hydrogel and its vasogenic effiicacy to evaluate its feasibility for clinical wound healing.Methods·Bisphosphonated hyaluronic acid(HAPD)was prepared via a blue-light mediated thiol-ene click reaction between thiolated hyaluronic acid(HASH)and acrylated bisphosphonate(Ac-PD)in the presence of photoinitiator 2959.Then,HAPD was further interacted with Cu2+through metal coordination to prepare HAPD-Cu hydrogels with different Cu2+concentrations,i.e.HAPD-Cu1,HAPD-Cu2,HAPD-Cu3 and HAPD-Cu4.The molecular structures of HASH,Ac-PD,HAPD and HAPD-Cu were verified with 1HNMR and FTIR.Microscopic morphology of HAPD-Cu was observed under SEM.The shear-thinning and self-healing properties of HAPD-Cu were verified by rheometer.The Cu2+release from HAPD-Cu was determined with ICP.Live-dead staining and CCK-8 assay were applied to evaluate the biocompatibility of HAPD-Cu.The in vitro vasculogenic activity of HAPD-Cu was determined by a tubule-forming assay with human umbilical vein vascular endothelial cells and the in vivo vasculogenic activity of HAPD-Cu was assessed by CD31 tissue staining.A rat wound defect model was established in vitro to evaluate its actual repair effect.Results·The preparation of the materials was demonstrated through chemical qualitative and quantitative analytical means.In vitro studies showed that all HAPD-Cu with a loose porous internal structure exhibited outstanding self-healing,injectability and degradability,with a one-week degradation cycle and abrupt release behavior,which can meet the needs of wound healing cycle.All HAPD-Cu showed good biocompatibility except HAPD-Cu4,due to its high Cu2+concentrations.Moreover,its angiogenic effect in vitro or in vivo was enhanced with increasing Cu2+concentrations within the permissible Cu2+concentration range.In vitro wound model experiments also showed that the HAPD-Cu hydrogel significantly promoted wound healing compared with the control group.Conclusion·HAPD-Cu hydrogel constructed via the metal coordination shows excellent shape plasticity,allowing the filling of defective sites in a minimally invasive form,and the release of Cu2+greatly facilitates the establishment of early vascular networks,with giant potential for use in the repair of clinically irregular wounds.

Research progress of HDACs and associated inhibitors on regulation of acute lung injury / 中国药理学通报

Acute lung injury ( ALI) and its most extreme form a-cute respiratory distress syndrome ( ARDS) are lung diseases with high morbidity and mortality. There is no effective therapeutic intervention until now for its complicated pathophysiologi-cal processes and sophisticated regulatory mechanism. Histone deacetylases (HDACs) are a family of proteins with deacetylase activity. Studies have shown that HDACs are involved in the pathophysiological processes of ALI/ARDS, including inflammatory responses,endothelial permeability,oxidative stresses,alveolar fluid clearance and lung tissue repairment. Simultaneously, the use of HDACs inhibitors (HDACIs) can interfere with ALI/ ARDS progression. In this review we describe and summarize the pathophysiological processes and the underlying mechanisms in ALI/ARDS regulated by HDACs and HDACIs in detail, in order to provide the basis for the clinical application of HDACs-targe- ted agents and indicate directions for future study.

Application of small molecular compounds in promoting the repair of dentin-pulp complex injury / 口腔医学

@#Dental caries, trauma, and iatrogenic stimulation can cause damage to the dentin-pulp complex. Preserving the viable pulp and promoting damage repair of the dentin-pulp complex is of great clinical significance at present. In recent years, studies have found that various small molecular compounds can regulate inflammation, promote the migration, proliferation, and differentiation of dental pulp stem cells, promote blood vessel, nerve regeneration and other biological processes by regulating key intracellular signaling pathways and metabolic pathways, and could thereby promote damage repair of the dentin-pulp complex. The objective of this paper is to review recent research on various small molecular compounds used in promoting the repair of dentin-pulp complex.

Review of the Benefits of Eggshell Content in Body Tissue Structure Repair

@#Eggshell (ES) is a waste material that cannot be consumed with low economic value. ES mainly contains calcium carbonate (CaCO3) and an organic matrix in the form of proteins, glycoproteins, and proteoglycans. Meanwhile, the eggshell membrane (ESM) contains osteopontin collagen, fibronectin, keratin, histones, avian beta defensins, ovocalyxin-36, apolipoproteins, protocadherin, chondroitin sulfate, ovotransferrin, hyaluronic acid, and sialic acid as well as various amino acids. Recently, ES has been widely used in industry, agriculture, food, and medical fields. The potential of ES in the medical field is interesting to discuss, especially in relation to tissue repair. Efforts to reduce the prevalence of wounds that generally originate from acute wounds but become chronic due to various factors that are neglected in their management. In particular, this review will describe the benefits of ES content in repairing body tissues. ES-derived active ingredients such as CaCO3, brushite, and hydroxyapatite exhibit osteoconductive properties that promote bone regeneration. Calcium ions can increase insulin and leptin sensitivity in the liver and can induce repair of acute kidney injury. Meanwhile, ESM contributes positively to neural tissue repair and plays an important role in wound healing, response to external stimuli, defense response, inflammatory response, cell-substrate adhesion, promoting cell growth, migration, differentiation, and tissue remodeling.

Research progress of adipose stem cell extracellular vesicles in skin wounds and tissue repair / 中国医师杂志

Adipose stem cells (ADSCs) are adult stem cells that originate from the mesoderm and exist in the adipose tissue matrix. They have strong proliferative ability and multi-directional differentiation potential. Exosomes are membranous vesicles released into the extracellular matrix after the fusion of intracellular vesicles and cell membranes. They have the characteristics of small size and can pass through biological cell barriers, and can mediate information exchange between cells. At present, the technology of isolating exosomes from ADSCs is quite mature and has been widely applied in various medical fields. This article will review the research progress of adipose stem cell exosomes (ADSCsexo) in skin wounds and tissue repair.

Plant stem cell extract from Coffea canephora shows antioxidant, anti-inflammatory, and skin regenerative properties mediated by suppression of nuclear factor-κB

Plant cell cultures have become a promising production platform of bioactive compounds for biomedical and cosmetic uses in the last decades. However, the success so far has been limited. The study aimed to evaluate the effectiveness of this unique biotechnology process to obtain a bioactive stem cell extract of Coffea canephora (SCECC) with antioxidant, anti-inflammatory, and regenerative properties. Total phenolic and flavonoid contents were determined in the SCECC by spectrophotometry. The chemical composition of the extracts was characterized by mass spectrometry. Antioxidant activity was evaluated using the colorimetric methods of free radical scavenging 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and the ferric reducing ability of plasma (FRAP). The anti-inflammatory activity was determined in lipopolysaccharide-stimulated RAW 264.7 macrophages through the production of superoxide anion (O2•-), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and the activity of nuclear factor kappa B (NF-κB). Moreover, the ability of SCECC to stimulate the proliferation and migration of fibroblasts was assessed. Five compounds were tentatively identified, two flavonoids, two phenolic acids, and one sugar. High phenolic content and antioxidant activity were observed in the SCECC. SCECC promoted the proliferation and migration of fibroblasts and suppressed the pro-inflammatory mediators O2•-, NO, TNF-α, and IL-6 in a dose-dependent manner. Moreover, SCECC inhibited the NF-κB transcription factor. Therefore, we obtained evidence that the extract from C. canephora stem cells can be used as a natural agent against skin damage. Hence, it could be of interest in cosmetics for preventing skin aging.

Eficácia e importância da patência foraminal em casos de dentes despolpados e em dentes com vitalidade pulpar / Efficacy and importance of apical foramen patency in procedures involving pulpless teeth and teeth with vital pulps

A ciência endodôntica possui um vasto conhecimento e com esse conhecimento os seus inúmeros questionamentos. Algumas teorias e conceitos mudam constantemente e trazem à tona contradições e divergências clínicas no âmbito biológico e prático. A patência foraminal é uma prática que permite que um instrumento de pequeno calibre ultrapasse o forame apical, com o intuito de limpar passivamente e prevenir o acúmulo de detritos e inibir a proliferação de microorganismos que podem causar infecções pós tratamento endodôntico. Essa prática gera discussão interna entre especialistas da área, mas as vantagens da técnica são inúmeras, principalmente no que diz respeito aos casos de polpa necrosada. Casos como esse não são solucionados com sucesso sem a utilização da patência apical. Por outro lado, existem contradições em relação aos casos em que a polpa está viva. Esse trabalho tem como objetivo analisar as vantagens e desvantagens da patência apical, bem como, se os benefícios excedem os possíveis danos que ela pode trazer(AU)

Endodontic science has vast knowledge and with this knowledge its countless questions. Some theories and concepts are constantly changing and bring to light clinical contradictions and divergences in the biological and practical scope. Foraminal patency is a practice that allows a small-caliber instrument to go beyond the apical foramen, in order to passively clean and prevent the accumulation of debris in the region and inhibit the proliferation of microorganisms that can cause infections after endodontic treatment. This practice generates internal discussion among specialists in the field, but the advantages of the technique are numerous, especially with regard to cases of necrotic pulp. Cases like this are not successfully resolved without the use of apical patency. On the other hand, there are contradictions regarding the cases where the pulp is alive. This work aims to analyze the advantages and disadvantages of apical patency, as well as whether the benefits exceed the harm it can bring(AU)

Eletrofiação aplicada a cicatrização de feridas: revisão de literatura / Electrospinning applied to wound healing: literature review / Electroalambre aplicado a la cicatrización de heridas: revisión de la literatura

feridas correspondem a interrupção da continuidade da pele, com a perda de uma ou mais camadas do tecido cutâneo. Curativos tradicionalmente aplicados em feridas cutâneas buscam principalmente fornecer uma barreira de proteção e permitir o desenvolvimento dos eventos celulares e bioquímicos que compreendem a cicatrização. Objetivou-se com este estudo apresentar sob a forma de revisão de literatura narrativa os principais eventos relacionados ao processo de reparo tecidual da pele, bem como abordar a aplicabilidade da técnica de eletrofiação no desenvolvimento de curativos funcionais biocompatíveis. Foram selecionados artigos voltados à caracterização dos eventos chave ocorridos a nível tecidual durante a cicatrização e, na sequência, buscou-se artigos voltados à produção, caracterização e aplicação de filmes nanoeletrofiados com ênfase na utilização de biopolímeros e substâncias bioativas. Observou-se que a maioria dos trabalhos recentes, voltados a pesquisa de base, descrevem a resposta vascular como o principal evento do processo cicatricial, sendo responsável pelas etapas que se desenrolam a seguir, que compreendem as fases inflamatória, proliferativa e de remodelamento, classicamente já descritas. Os curativos funcionais baseados em polímeros eletrofiados apresentam resultados superiores quanto testados in vitro e in vivo. As características morfoestruturais mimetizam a matriz extracelular e podem atuar em tecidos alvo como dispositivos de entrega de substâncias. Conclui-se que a atualização e reorganização de conceitos relativos à cicatrização podem contribuir no desenvolvimento de inovações, como os curativos produzidos por eletrofiação. Embora promissora, as desvantagens da técnica encontram-se principalmente no processo de obtenção e disponibilidade, que limitam a aplicação clínica em escala comercial.

Wounds correspond to the interruption of skin continuity, with the loss of one or more layers of skin tissue. Dressings traditionally applied to cutaneous wounds mainly seek to provide a protective barrier and allow the development of cellular and biochemical events that comprise healing. The objective of this study was to present, in the form of a narrative literature review, the main events related to the skin tissue repair process, as well as to address the applicability of the electrospinning technique in the development of biocompatible functional dressings. Articles focused on the characterization of the key events that occurred at the tissue level during healing were selected and, subsequently, articles focused on the production, characterization and application of nanoelectrospun films with emphasis on the use of biopolymers and bioactive substances were sought. It was observed that most recent works, focused on basic research, describe the vascular response as the main event of the healing process, being responsible for the steps that follow, which include the inflammatory, proliferative and remodeling phases, classically already described. Functional dressings based on electrospun polymers show superior results when tested in vitro and in vivo. The morphostructural features mimic the extracellular matrix and can act in target tissues as substance delivery devices. It is concluded that the updating and reorganization of concepts related to healing can contribute to the development of innovations, such as dressings produced by electrospinning. Although promising, the technique's disadvantages lie mainly in the process of obtaining and availability, which limit clinical application on a commercial scale.

Las heridas corresponden a la interrupción de la continuidad de la piel, con la pérdida de una o más capas de tejido cutáneo. Los apósitos aplicados tradicionalmente a las heridas cutáneas buscan principalmente proporcionar una barrera protectora y permitir el desarrollo de los eventos celulares y bioquímicos que comprenden la curación. El objetivo de este estudio fue presentar en forma de revisión bibliográfica narrativa los principales acontecimientos relacionados con el proceso de reparación tisular de la piel, así como abordar la aplicabilidad de la técnica de electrodeposición en el desarrollo de apósitos funcionales biocompatibles. Se seleccionaron artículos dirigidos a la caracterización de los eventos chave ocurridos a nivel técnico durante la cicatrización y, a continuación, se buscaron artículos dirigidos a la producción, caracterización y aplicación de películas nanoelectrofíricas con énfasis en el uso de biopolímeros y sustancias bioativas. Se observa que la mayoría de los trabajos recientes, realizados en la investigación de base, describen la respuesta vascular como el principal evento del proceso cicatricial, siendo responsable de las etapas que se desarrollan a continuación, que comprenden las fases inflamatoria, proliferativa y de remodelación, clásicamente descritas. Los apósitos funcionales basados en polímeros electro-tejidos presentan resultados superiores cuando se prueban in vitro e in vivo. Las características morfoestruturales mimetizan la matriz extracelular y pueden actuar en tejidos alvos como dispositivos de entrega de sustancias. Se concluye que la actualización y la reorganización de los conceptos relativos a la cicatrización pueden contribuir al desarrollo de innovaciones, como las curativas producidas por la electrofagia. Aunque es prometedora, las desventajas de la técnica radican principalmente en el proceso de obtención y la disponibilidad, que limitan la aplicación clínica a escala comercial.

Decellularized extracellular matrix mediates tissue construction and regeneration / 医学前沿

Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell-matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.

Gracilis musculocutaneous flap in repair of perineal soft tissue defect with open pelvic fracture / 中华显微外科杂志

Objective:To investigate the clinical effect of gracilis musculocutaneous flap in repair of perineal soft defect with open pelvic fracture.Methods:From June 2009 to June 2019, 11 cases of open pelvic fracture associated with perineal injury were treated in the Department of Trauma and Orthopaedic of 521 Hospital of Norinco Group. There were 4 males and 7 females aged 16-56 (33 in average) years old. Cause of injuries: 6 cases by traffic accident, 4 by falling from height, and 1 by crushing. All the patients had open pelvic fractures. According to Tile classification, 1 case was rated as type A, 7 as type B and 3 as type C. All the patients were accompanied with perineal injury and soft tissue defect. The wound sizes ranged from 5 cm×5 cm to 8 cm×12 cm. The defects were repaired with gracilis musculocutaneous flap. The size of gracilis myocutaneous flaps was 6 cm×5 cm to 9 cm×13 cm. All donor areas of the flap were sutured directly. After surgery, 11 patients treated with strengthened nutritional support, keep supine position to avoid abduction, and appropriately raise the lower limbs. Follow-ups were conducted regularly after surgery.Results:All patients entered 6 to 30 (22 in average) months of follow-up. All of 11 myocutaneous flaps survived, besides 1 had a few necrosis at the distal surface of the myocutaneous flap, and healed after change of dressing. All the incisions at donor site had stage I healing. The colour, texture and flexibility of the gracilis myocutaneous flap were good. There was a scar at the donor sites without causing obvious dysfunction. Over the follow-up period, there was no failure of flap in either the recipient and donor sites. The patients were satisfied with the appearance and function.Conclusion:Gracilis musculocutaneous flap is one of the ideal methods in repair of perineal soft tissue defect with open pelvic fracture.

Extracts of Portulaca oleracea promote wound healing by enhancing angiology regeneration and inhibiting iron accumulation in mice / 中草药·英文版

Objective: To investigate the role of Portulaca oleracea (POL) in promoting revascularization and re-epithelization as well as inhibiting iron aggregation and inflammation of deep tissue pressure injury (DTPI). Methods: The hydroalcoholic extract of POL (P) and aqueous phase fraction of POL (PD) were prepared based on maceration and liquid–liquid extraction. The number of new blood vessels and VEGF-A expression level were assessed using H&E stain and Western blot on injured muscle to examine the role of POL different extracts in vascularization. The iron distribution and total elemental iron of injured muscle were detected using laser ablation inductively coupled plasma mass spectrometry (ICP-MS) and Perls’ staining to determine whether POL extracts can inhibit the iron accumulation. Besides, the ability of POL extracts to promote wound healing by combining re-epithelization time, inflammation degree and collagen deposition area were comprehensively evaluated. Results: In vitro, we observed a significant increase in HUVEC cell viability, migration rate and the number of the tube after P and PD treatment (P < 0.05). In vivo, administration of P and PD impacted vascularization and iron accumulation on injured tissue, evident from more new blood vessels, higher expression of VEGF-A and decreased muscle iron concentration of treatment groups compared with no-treatment groups (P < 0.05). Besides, shorter re-epithelization time, reduced inflammatory infiltration and distinct collagen deposition were associated with administration of P and PD (P < 0.05). Conclusion: POL extract administration groups have high-quality wound healing, which is associated with increased new blood vessels, collagen deposition and re-epithelization, along with decreased iron accumulation and inflammatory infiltration. Our results suggest that that POL extract is beneficial to repair injured muscle after ischemia–reperfusion, highlighting the potential of POL in the DTPI treatment.

Research progress in role and mechanism of neutrophils in tissue repair / 中华创伤杂志

Damage to skin, muscle, bone and nerve tissues can result in various degrees of damage to the body, leading to organ dysfunction even life-threatening. To restore the structure and function of the damaged tissues, various immune cells and histocytes have successively participated in the tissue repair process. As the terminally differentiated white blood cells, neutrophils can remove necrotic tissue, debris and pathogens via phagocytosis and release of antimicrobial peptides after tissue injury to provide conditions for subsequent tissue repair process. However, enhanced neutrophils recruitment as well as excessive inflammatory response may also aggravate tissue damage. In recent years, more and more evidences indicate that neutrophils display plasticity and heterogeneity and that play critical roles in the initiation of tissue repair, promotion of angiogenesis, regulation of cell proliferation and so on. Herein, the authors review the recruitment, phenotype and function, role and outcome of neutrophils during tissue repair so as to provide references for future studies.