富血小板血浆促进牵拉成骨的矿化过程

BACKGROUND: The platelet-rich plasma contains various growth factors that could enhance the regeneration of certain tissues. OBJECTIVE: To observe the effect of platelet-rich plasma on the mineralization process during distraction osteogenesis in rabbits. METHODS: Thirty-two adult Japanese white rabbits were randomly divided into four groups (n=8 per group). The upper 1/3 tibial osteotomy at the posterior limb was performed in all rabbits, and the 1 cm limb lengthening models were prepared, followed by the local injection of 500 μL platelet-rich plasma at 5, 15 and 25 days. The controls received no treatment. At 37 days after modeling, the rabbits were killed and newly formed callus was removed to undergo hematoxylin-eosin staining, and the frontal X-ray film of tibia was obtained. RESULTS AND CONCLUSION: Lane-Sandhu radiographic scoring showed that the scores in the injection groups at 15 and 25 days after modeling were obviously better than those in the control group and the injection at 5 days after modeling. Lane-Sandhu histological scoring revealed that the scores in the injected groups at 15 and 25 days after modeling were significantly higher than those in the control group and group at 5 days after modeling (P < 0.05), which highest at 25 days. These results suggest that local injection of platelet-rich plasma can promote bone mineralization during distraction osteogenesis effectively, especially in the middle period of distraction osteogenesis. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

The effect of a bioactive collagen membrane releasing PDGF or GDF-5 on bone regeneration

Regenerative procedures using barrier membrane technology are presently well established in periodontal/endodontic surgery. The objective of this study was to compare the subsequent effects of the released platelet-derived growth factor (PDGF) and growth/differentiation factor 5 (GDF-5) from collagen membranes (CMs) on bone regeneration in vitro and in vivo. In vitro studies were conducted using MC3T3-E1 mouse preosteoblasts cultured with or without factors. Cell viability, cell proliferation, alkaline phosphatase (ALP) activity and bone marker gene expression were then measured. In vivo studies were conducted by placing CMs with low or high dose PDGF or GDF-5 in rat mandibular defects. At 4 weeks after surgery new bone formation was measured using μCT and histological analysis. The results of in vitro studies showed that CM/GDF-5 significantly increased ALP and cell proliferation activities without cytotoxicity in MC3T3-E1 cells when compared to CM/PDGF or CM alone. Gene expression analysis revealed that Runx2 and Osteocalcin were significantly increased in CM/GDF-5 compared to CM/PDGF or control. Quantitative and qualitative μCT and histological analysis for new bone formation revealed that although CM/PDGF significantly enhanced bone regeneration compared to CM alone or control, CM/GDF-5 significantly accelerated bone regeneration to an even greater extent than CM/PDGF. The results also showed that GDF-5 induced new bone formation in a dose-dependent manner. These results suggest that this strategy, using a CM carrying GDF-5, might lead to an improvement in the current clinical treatment of bone defects for periodontal and implant therapy.     

Role of collagen cross-linking on equine wound contraction and healing

The present study was carried out to evaluate the effect of collagen cross-linking inhibition on equine wound contraction and healing. In five male adult donkeys, two full-thickness skin wounds (20 × 20 mm in diameter) were created on the lateral aspect of forelimbs, at the mid-point between the carpal and fetlock joints under general anesthesia. Two other wounds were created on the neck of each donkey symmetrically. Left-side wounds (test group) and right-side wounds (control group) were treated topically with beta-aminopropionitrile fumarate, 5 mg/ml, added to methyl cellulose gel and only methyl cellulose gel, respectively. Treatment of wounds were started at 24 h after wounding and continued every other day for ten successive days. The wounds were evaluated over a 3-week period. On days 0, 1, 3, 5, 7, 9, 12, 15, 18, and 21, digital photographs were taken of all wounds after careful shaving to visualize the wound margin. Rulers were held vertically and horizontally close to the wound as a reference. Epithelialization and granulation tissue formation were measured for each wound using Scion Image software. Percentage of the wound contraction, epithelialization, and healing were calculated for each wounds. At the end of the study, biopsy was taken from the center of each wound for hydroxyproline measurement and the same corner of each wound for histopathological examination. Macroscopic evaluation revealed significant differences in wound contraction and healing process between test and control groups in wounds located in neck (P < 0.05), but there was no significant difference in percent of epithelialization at the same area (P > 0.05). Significant differences were observed in the percent of wound contraction and healing between the test and control groups in wounds located in the forelimb (P < 0.05), but no significant difference was observed in percent of epithelialization at this area (P > 0.05). There were no significant differences between median of hydroxyproline levels of left and right wounds in forelimb and neck (P > 0.05). Histopathological examination revealed no significant differences between median of epithelialization, inflammatory infiltration, presence of dermal granulation tissue, fibroblast proliferation, arrangement of fibroblasts, collagen deposition, and collagen bundle formation scores in the specimens prepared from left and right wounds in forelimb and neck (P > 0.05). Our data demonstrated that collagen cross-linking could play a key role in equine wound contraction and healing at the limb and neck area.     

Comprehensive characterization of myeloid cells during wound healing in healthy and healing-impaired diabetic mice

Wound healing involves the concerted action of various lymphoid and in particular myeloid cell populations. To characterize and quantitate different types of myeloid cells and to obtain information on their kinetics during wound healing, we performed multiparametric flow cytometry analysis. In healthy mice, neutrophil numbers increased early after injury and returned to near basal levels after completion of healing. Macrophages, monocyte-derived dendritic cells (DCs), and eosinophils were abundant throughout the healing phase, in particular in early wounds, and Langerhans cells increased after wounding and remained elevated after epithelial closure. Major differences in healing-impaired diabetic mice were a much higher percentage of immune cells in late wounds, mainly as a result of neutrophil, macrophage, and monocyte persistence; reduced numbers and percentages of macrophages and monocyte-derived DCs in early wounds; and of Langerhans cells, conventional DCs, and eosinophils throughout the healing process. Finally, unbiased cluster analysis (PhenoGraph) identified a large number of different clusters of myeloid cells in skin wounds. These results provide insight into myeloid cell diversity and dynamics during wound repair and highlight the abnormal inflammatory response associated with impaired healing.     

损伤皮肤修复和伤口愈合过程中的干细胞：问题与前景

BACKGROUND:Present treatments for chronic skin wounds have certain limitations, and adult stem cells play a potential part in cutaneous repair and regeneration. OBJECTIVE:To review effects of stem cells in skin regeneration and wound healing. METHODS:The first author retrieved CNKI and Medline databases by computer for relevant articles published from 2000 to 2010. The keywords were “epidermal stem cells, hair follicle stem cells, stem cells, transplantation, dermal stem cells” in Chinese and in English, respectively. Then totally 489 papers were obtained after initial survey, and according to the inclusion criteria, 30 articles were selected for review. RESULTS AND CONCLUSION:Epidermal stem cells and other adult stem cells have been applied to treat wounds and other skin diseases. Epidermal stem cells are the crucial cell source of skin development, repair and remodeling. Epidermal stem cells are always in a resting state in vivo. Unless, skin injure or culture in vitro, cell division and proliferation will be significantly fastened. The stability of the epidermis mainly depends on the asymmetric division of a subpopulation, in which two daughter cells are produced, including one with characteristics of stem cells, and the other differentiated into transient amplifying cells that will be differentiated into post mitotic cells after a series of cell divisions (3-5 times). Afterwards, those post mitotic cells are developed into terminal differentiation cells on the basal layer, finally detach from the epidermis as dander. In addition, it is unclear whether epidermal factors are related to apoptosis, migration and differentiation in the process of wound repair and even under physiological conditions. Therefore, application of stem cells in wound healing requires a further discussion.     

Topical pluronic F-127 gel application enhances cutaneous wound healing in rats

Pluronic F-127 gel is used as vehicle for various topical applications. In the present study, effects of topical application of pluronic F-127 gel were evaluated in cutaneous wound healing in Wistar rats. Normal saline solution and pluronic F-127 gel (25%) were applied topically on open excision wounds for 14 days. Photography, determination of percentage wound contraction, and collection of granulation tissue were done on days 3, 7, 11 and 14 post-wounding. Topical application of gel (once daily) significantly increased the wound closure on days 11 and 14. The gel application increased the expressions of vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-β₁) on days 3 and 7. Histopathologically, more leukocyte infiltration followed by well formed granulation tissue with marked fibroblast proliferation was evident in the gel-treated group, as compared to the saline-treated control group. Immunohistochemistry of CD31 on day 7 revealed significant higher microvessel density in gel-treated wounds. Picrosirius staining demonstrated higher collagen fraction in gel-treated wounds. Thus, from the results, it could be concluded that pluronic F-127 gel has a mild inflammatory nature and enhanced the healing by stimulating expression of VEGF and TGF-β₁.     

Drosophila as a model of wound healing and tissue regeneration in vertebrates

Understanding the molecular basis of wound healing and regeneration in vertebrates is one of the main challenges in biology and medicine. This understanding will lead to medical advances allowing accelerated tissue repair after wounding, rebuilding new tissues/organs and restoring homeostasis. Drosophila has emerged as a valuable model for studying these processes because the genetic networks and cytoskeletal machinery involved in epithelial movements occurring during embryonic dorsal closure, larval imaginal disc fusion/regeneration, and epithelial repair are similar to those acting during wound healing and regeneration in vertebrates. Recent studies have also focused on the use of Drosophila adult stem cells to maintain tissue homeostasis. Here, we review how Drosophila has contributed to our understanding of these processes, primarily through live-imaging and genetic tools that are impractical in mammals. Furthermore, we highlight future research areas where this insect may provide novel insights and potential therapeutic strategies for wound healing and regeneration.     

神经再生素促进神经干细胞的生长和分化

目的:研究神经再生素对体外培养神经干细胞分化的促进作用及对其生长相关蛋白(GAP43)、神经丝蛋白(NF-H)表达的影响.方法:取出生3～5d的新生SD大鼠大脑皮层进行神经干细胞的体外培养、鉴定,神经干细胞与0、 1、 2mg/L的神经再生素(NRF)共培养8d,相差显微镜观察分析,应用Real-time PCR对与不同浓度的NRF(0、 1、 2、 4、 8mg/L)共培养8d的神经干细胞进行GAP43、 NF-H的表达量检测.结果:成功培养出具有多向分化潜能的神经干细胞;神经再生素可明显促进神经干细胞的分化,并能在一定范围内随浓度递增而有效促进GAP43、 NF-H的表达,且最佳作用浓度为4mg/L.结论:神经再生素可以促进神经干细胞的生长和分化.     

Effect of polyurethane chemistry and protein coating on monocyte differentiation towards a wound healing phenotype macrophage

Tissue regeneration alternatives for peripheral vascular disease are actively being investigated; however, few studies in this area have probed the role of the wound healing monocyte-derived macrophage (MDM). Inflammatory MDMs transition to wound healing MDMs as the relative levels of tumor necrosis factor-alpha (TNF-α) decrease and IL-10 increase. TNF-α has been linked to the regulation of HMGB1 (high mobility group box 1 protein), a nuclear protein that upon macrophage stimulation can be secreted and act as a pro-inflammatory cytokine. This study investigated the influence of a degradable polar hydrophobic ionic polyurethane (D-PHI) on MDM cell expression of pro- versus anti-inflammatory markers, when the material was uncoated or pre-coated with collagen prior to cell studies. Effects were compared to similar groups on tissue culture polystyrene (TCPS). Collagen coated TCPS and D-PHI had significantly more DNA than the uncoated TCPS after 7d (p = 0.001 and p = 0.006 respectively); however, there was significantly less esterase activity from cells on D-PHI (±collagen) than for cells on TCPS after 7d (p = 0.002, p = 0.0003 respectively). No significant differences in esterase activity were observed between collagen coated and non-coated D-PHI surfaces. Analyses of pro-inflammatory cytokines (TNF-α, IL-1β and HMGB1) secreted from differentiating monocytes adherent to D-PHI demonstrated a decrease whereas anti-inflammatory IL-10 increased over time when compared to TCPS, suggesting that D-PHI was less inflammatory than TCPS. Since D-PHI maintains cell attachment while aiding in the transition of MDM to a wound healing phenotype, this material has qualities suitable to be used in tissue engineering applications where MDM play a key role in tissue regeneration.     

Stromal vascular fraction promotes fibroblast migration and cellular viability in a hyperglycemic microenvironment through up-regulation of wound healing cytokines

Diabetic wounds have impaired healing and a propensity for further morbidity, which may result in amputations. Stromal vascular fraction (SVF) is an autologous source of heterogeneous cell population obtained from adipose tissue, which is rich in stem cells and presents little immunogenicity to the host. In this study, we hypothesized that murine fibroblasts subjected to hyperglycemic conditions co-treated with SVF exhibit greater functional activity through the colorimetric MTT assay and a cell-monolayer in-vitro scratch assay. We sought to establish the underlying mechanism of action via the utility of an ELISA chemiluminescence array on the supernatant medium of the cells. Our results demonstrate that the mean percentage gap closure at 24?h in the hyperglycemia?+?SVF group was significantly greater at 41.1%?±?1.6% compared to the hyperglycemia alone group 16.6%?±?1.5% (post-hoc Bonferroni test p?<?0.001, n?=?3) although there was no difference between the SVF and normoglycemia group. Further, this SVF group exhibited a significantly greater 2.4 fold increase in fibroblastic cell viability as compared to the hyperglycemia alone group (p?=?0.001, n?=?3). The supernatant medium of the cells upon testing with ELISA indicated that early phase wound healing cytokines including platelet-derived growth factor (p?=?0.012, n?=?3), interleukin-1 (p?=?0.003, n?=?3), basic fibroblast growth factor (p?=?0.003, n?=?3) and interleukin-10 (p?=?0.009, n?=?3) were expressed in significantly greater relative luminescent units in SVF as compared to hyperglycemia alone groups (Student t-test). Taken together and for the first time, our study shows that SVF is a promising therapeutic agent for up-regulating fibroblastic activity in a hyperglycemic microenvironment, and this result can be explained in part by the stimulation of wound-healing cytokines.     

Dramatic promotion of wound healing using a recombinant human-like collagen and bFGF cross-linked hydrogel by transglutaminase

Abstract

The basic fibroblast growth factor (bFGF) plays an important role in the wound repair process. However, lacking of better biomaterials to carry bFGF still is a challenge in skin repair and regeneration. In this study, the human-like collagen (HLC) cross-linked with transglutaminase (TG) to fabricate a HLC/TG hydrogel to load bFGF. The physical properties of hydrogel, such as interior structure, mechanical property, were characterized in vitro using scanning electron microscopy (SEM), rheometer. Then, the effects of the HLC/TG hydrogel on the bFGF and cell attachmentwere evaluated, and the results showed that the HLC/TG hydrogel has good biocompatibility towards bFGF and cells. Finally, skin wound healing test was performed for the evaluation of HLC/TG hydrogels with bFGF in a mouse model. All results of macroscopic and microscopic analysis indicated that not only our HLC/TG hydrogel provide a delivery of growth factors, but also the HLC/TG hydrogel with bFGF achieving better skin regeneration in the structure and function.     

Adenovirus-mediated expression of growth and differentiation factor-5 promotes chondrogenesis of adipose stem cells

The repair of articular cartilage injuries is impeded by the avascular and non-innervated nature of cartilage. Transplantation of autologous chondrocytes has a limited ability to augment the repair process due to the highly differentiated state of chondrocytes and the risks of donor-site morbidity. Mesenchymal stem cells can undergo chondrogenesis in the presence of growth factors for cartilage defect repair. Growth and differentiation factor-5 (GDF5) plays an important role in chondrogenesis. In this study, we examined the effects of GDF5 on chondrogenesis of adipose-derived stem cells (ADSCs) and evaluate the chondrogenic potentials of GDF5 genetically engineered ADSCs using an in vitro pellet culture model. Rat ADSCs were grown as pellet cultures and treated with chondrogenic media (CM). Induction of GDF5 by an adenovirus (Ad-GDF5) was compared with exogenous supplementation of GDF5 (100 ng/ml) and transforming growth factor-β (TGF-β1; 10 ng/ml). The ADSCs underwent chondrogenic differentiation in response to GDF5 exposure as demonstrated by production of proteoglycan, and up-regulation of collagen II and aggrecan at the protein and mRNA level. The chondrogenic potential of a one-time infection with Ad-GDF5 was weaker than exogenous GDF5, but equal to that of TGF-β1. Stimulation with growth factors or CM alone induced transient expression of the mRNA for collagen X, indicating a need for optimization of the CM. Our findings indicate that GDF5 is a potent inducer of chondrogenesis in ADSCs, and that ADSCs genetically engineered to express prochondrogenic growth factors, such as GDF5, may be a promising therapeutic cell source for cartilage tissue engineering.     

Physical plasma therapy accelerates wound re-epithelialisation and enhances extracellular matrix formation in cutaneous skin grafts

Skin grafting is a surgical method of cutaneous reconstruction, which provides volumetric replacement in wounds unable to heal by primary intention. Clinically, full-thickness skin grafts (FTSGs) are placed in aesthetically sensitive and mechanically demanding areas such as the hands, face, and neck. Complete or partial graft failure is the primary complication associated with this surgical procedure. Strategies aimed at improving the rate of skin graft integration will reduce the incidence of graft failure. Cold atmospheric plasma (CAP) is an emerging technology offering innovative clinical applications. The aim of this study was to test the therapeutic potential of CAP to improve wound healing and skin graft integration into the recipient site. In vitro models that mimic wound healing were used to investigate the ability of CAP to enhance cellular migration, a key factor in cutaneous tissue repair. We demonstrated that CAP enhanced the migration of epidermal keratinocytes and dermal fibroblasts. This increased cellular migration was possibly induced by the low dose of reactive oxygen and nitrogen species produced by CAP. Using a mouse model of burn wound reconstructed with a full-thickness skin graft, we showed that wounds treated with CAP healed faster than did control wounds. Immunohistochemical wound analysis showed that CAP treatment enhanced the expression of the dermal–epidermal junction components, which are vital for successful skin graft integration. CAP treatment was characterised by increased levels of Tgfbr1 mRNA and collagen I protein in vivo, suggesting enhanced wound maturity and extracellular matrix deposition. Mechanistically, we show that CAP induced the activation of the canonical SMAD-dependent TGF- β 1 pathway in primary human dermal fibroblasts, which may explain the increased collagen I synthesis in vitro. These studies revealed that CAP improved wound repair and skin graft integration via mechanisms involving extracellular matrix formation. CAP offers a novel approach for treating cutaneous wounds and skin grafts. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

The interplay between extracellular matrix and progenitor/stem cells during wound healing: Opportunities and future directions

Skin wound healing, a dynamic physiological process, progresses through coordinated overlapping phases to restore skin integrity. In some pathological conditions such as diabetes, wounds become chronic and hard-to-heal resulting in substantial morbidity and healthcare costs. Despite much advancement in understanding mechanisms of wound healing, chronic and intractable wounds are still a considerable challenge to nations’ health care systems. Extracellular matrix (ECM) components play pivotal roles in all phases of wound healing. Therefore, a better understanding of their roles during wound healing can help improve wound care approaches. The ECM provides a 3D structure and forms the stem cell niche to support stem cell adhesion and survival and to regulate stem cell behavior and fate. Also, this dynamic structure reserves growth factors, regulates their bioavailability and provides biological signals. In various diseases, the composition and stiffness of the ECM is altered, which as a result, disrupts bidirectional cell-ECM interactions and tissue regeneration. Hence, due to the impact of ECM changes on stem cell fate during wound healing and the possibility of exploring new strategies to treat chronic wounds through manipulation of these interactions, in this review, we will discuss the importance/impact of ECM in the regulation of stem cell function and behavior to find ideal wound repair and regeneration strategies. We will also shed light on the necessity of using ECM in future wound therapy and highlight the potential roles of various biomimetic and ECM-based scaffolds as functional ECM preparations to mimic the native stem cell niche.     

脂肪干细胞无细胞提取液的治疗用途:皮肤老化、创面愈合、瘢痕恢复乃至神经再生

背景:脂肪干细胞无细胞提取液包括脂肪干细胞条件培养基、脂肪干细胞外泌体,因其不含细胞,易于携带、储存和运输,已成为当前最热门的治疗方法之一.目的:对脂肪干细胞无细胞提取液治疗用途的研究进展作一综述.方法:以脂肪干细胞、基质细胞与条件培养基脂肪干细胞、基质细胞与外泌体为中文检索词,adipose stem ce...     

大鼠皮肤创伤修复过程中转化生长因子β1和β3的表达

背景：转化生长因子β在组织创伤修复中发挥核心和关键作用。 目的：观察转化生长因子β1和转化生长因子β3在大鼠皮肤瘢痕性创伤愈合过程中表达量及表达部位的变化。 方法：制备大鼠皮肤全层切伤模型,长度1.5-2.0 cm,深及筋膜层。于伤后0 h,12 h,1 d,2 d,3 d,4 d,5 d,6 d,7 d处死大鼠,取损伤部位皮肤,采用免疫组织化学染色检测各时间点转化生长因子β1和转化生长因子β3的表达,并进行定量分析。 结果与结论：免疫组织化学染色显示,在创伤愈合的早期阶段(伤后1-5 d),转化生长因子β1和转化生长因子β3免疫阳性颗粒主要出现在上皮细胞、上皮基底层细胞胞浆、巨噬细胞等免疫细胞胞浆及肉芽组织中;随着创伤修复时间的持续,免疫阳性颗粒主要出现在真皮层的成纤维细胞及细胞外基质中。其中转化生长因子β1的表达在创伤后1-5 d最强,而转化生长因子β3在创伤后六七天时开始明显表达。可见在大鼠皮肤瘢痕性创伤愈合过程中,转化生长因子β1的表达先于转化生长因子β3,提示转化生长因子β1与胶原形成及创伤修复关系密切,而转化生长因子β3在愈合后期表达量有升高趋势,其可能与创伤后期的组织改建密切相关。     

Ⅳ期压疮愈合过程中创面渗出液基质金属蛋白酶-9、基质金属蛋白酶抑制剂-1的表达水平变化的研究

目的探讨Ⅳ期压疮愈合过程中创面渗出液中基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶抑制剂-1(TIMP-1)的表达情况及其与压疮愈合的关系。 方法选择2017年7月至2018年4月在河北省人民医院就诊的Ⅳ期压疮患者39例,创面共59处,根据接诊时与治疗第4周末压疮愈合评估表(PUSH)评分差值进行分组,差值>2分为愈合良好组(n＝26),≤2分为愈合不良组(n＝13)。按照统一方法评估、清洗及清创后,选择合适的治疗方案进行换药,追踪4周,采集接诊时、治疗第1周末、第2周末、第3周末、第4周末创面渗出液,酶联免疫吸附测定法检测2组创面渗出液中MMP-9、TIMP-1表达水平及MMP-9/TIMP-1比值的变化情况。数据比较采用t检验。 结果接诊时及治疗第1周末2组MMP-9表达差异无统计学意义(t＝1.262、1.944,P值均大于0.05),而在治疗第2周末、第3周末、第4周末愈合不良组MMP-9表达水平分别为(189.27±90.15) ng/L、(176.95±75.47) ng/L、(149.30±63.08) ng/L,显著高于愈合良好组[(114.97±70.06) ng/L、(93.75±55.15) ng/L、(71.62±41.66) ng/L],差异有统计学意义(t＝2.835、3.921、4.608,P值均小于0.05);不同时间点愈合良好组与愈合不良组TIMP-1表达水平比较,差异均无统计学意义(t＝0.346、0.292、0.047、0.395、0.999,P值均大于0.05);接诊时及治疗第1周末2组MMP-9/TIMP-1比值差异均无统计学意义(t＝1.023、1.134, P值均大于0.05),而在治疗第2周末、第3周末、第4周末时愈合不良组MMP-9/TIMP-1比值分别为(38.42±9.25)、(33.74±9.58)、(29.53±8.04),显著高于愈合良好组的(30.04±10.67)、(25.35±10.18)、(21.54±9.29),差异均有统计学意义(t＝2.411、2.473、2.642,P值均小于0.05)。 结论创面渗出液中MMP-9表达水平及MMP-9/TIMP-1比值变化与压疮愈合有关,过高的MMP-9及MMP-9/TIMP-1不利于压疮的愈合。     

Role of MR1-driven signals and amphiregulin on the recruitment and repair function of MAIT cells during skin wound healing

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