Collagen membranes loaded with collagen-binding human PDGF-BB accelerate wound healing in a rabbit dermal ischemic ulcer model

Studies have shown that exogenous platelet-derived growth factor-BB (PDGF-BB) could accelerate the ulcer healing, but the lack of efficient growth factor delivery system limits its clinical application. Our previous work has demonstrated that the native human PDGF-BB was added a collagen-binding domain (CBD), TKKTLRT, to develop a collagen-based PDGF targeting delivery system. Here, we showed that this CBD-fused PDGF-BB (CBD-PDGF) could bind to collagen membrane efficiently. We used the rabbit dermal ischemic ulcer model to study the effects of CBD-PDGF loaded on collagen membranes. Results revealed that this system maintained a higher concentration and stronger bioactivity of PDGF-BB on the collagen membranes and promoted the re-epithelialization of dermal ulcer wounds, the collagen deposition, and the formation of capillary lumens within the newly formed tissue area. It demonstrated that collagen membranes loaded with collagen-targeting human PDGF-BB could effectively promote ulcer healing.     

The effect of collagen-targeting platelet-derived growth factor on cellularization and vascularization of collagen scaffolds

Platelet-derived growth factor BB (PDGF-BB) was an important inductive factor during wound healing, but the lack of efficient delivery system limited its clinical application. Here, a peptide of seven amino acids was firstly utilized to engineer PDGF-BB to construct a collagen-targeting system. This peptide functioned as collagen-binding domain (CBD) to specially target the PDGF-BB to the collagen and restrict its diffusion. In our study, in vitro activity assay showed that the CBD-fused PDGF (CBD-PDGF) and native PDGF (NAT-PDGF) possessed similar activity to stimulate the human fibroblast proliferation. As expected, this peptide promoted the binding of PDGF to collagen scaffolds, and CBD-PDGF caused more cells to proliferate on the collagen gel than NAT-PDGF when the same amounts of PDGF were added. In the in vivo experiment, CBD-PDGF-loaded collagen scaffolds were uniformly cellularized and vascularized compared to that of NAT-PDGF-loaded scaffolds. Our study demonstrated that the CBD targeted PDGF to the collagen scaffold to exert its functions, and it suggested this could be an effective system for targeting tissue regeneration and wound repair.     

Dual growth factor releasing multi-functional nanofibers for wound healing

The objective of this research is to develop a dual growth factor-releasing nanoparticle-in-nanofiber system for wound healing applications. In order to mimic and promote the natural healing procedure, chitosan and poly(ethylene oxide) were electrospun into nanofibrous meshes as mimics of extracellular matrix. Vascular endothelial growth factor (VEGF) was loaded within nanofibers to promote angiogenesis in the short term. In addition, platelet-derived growth factor-BB (PDGF-BB) encapsulated poly(lactic-co-glycolic acid) nanoparticles were embedded inside nanofibers to generate a sustained release of PDGF-BB for accelerated tissue regeneration and remodeling. In vitro studies revealed that our nanofibrous composites delivered VEGF quickly and PDGF-BB in a relayed manner, supported fibroblast growth and exhibited anti-bacterial activities. A preliminary in vivo study performed on normal full thickness rat skin wound models demonstrated that nanofiber/nanoparticle scaffolds significantly accelerated the wound healing process by promoting angiogenesis, increasing re-epithelialization and controlling granulation tissue formation. For later stages of healing, evidence also showed quicker collagen deposition and earlier remodeling of the injured site to achieve a faster full regeneration of skin compared to the commercial Hydrofera Blue® wound dressing. These results suggest that our nanoparticle-in-nanofiber system could provide a promising treatment for normal and chronic wound healing.     

Promotion of peripheral nerve growth by collagen scaffolds loaded with collagen-targeting human nerve growth factor-beta

Nerve growth factor (NGF) plays a critical role in neuronal development and regeneration. However, the lack of efficient NGF delivery system limits its clinical application. We reported that a peptide deduced from collagenase, TKKTLRT, fused with NGF-beta could develop a collagen based NGF targeting delivery system. Our results showed that this peptide could allow fused NGF-beta bind to collagen specifically. In addition, we found that the polypeptide could result in a 2.3-fold increase in the expression level and a significant improvement of bioactivity of fused NGF-beta. In the in vivo function study, collagen membranes loaded with the collagen binding NGF enhanced the nerve growth. Thus, the targeting wound repair system could be important for the repair of peripheral nerve injury.     

A myocardial patch made of collagen membranes loaded with collagen-binding human vascular endothelial growth factor accelerates healing of the injured rabbit heart

Tissue-engineered myocardial patches could be useful in the repair of myocardial injuries. The aim of the present study was to evaluate a collagen targeting delivery system for myocardial repair. A specific peptide collagen-binding domain (CBD) was fused to human vascular endothelial growth factor (VEGF) to enhance the binding of VEGF to collagen. In this study, collagen membranes loaded with CBD-VEGF, natural VEGF, or phosphate-buffered saline are used as cardiac patches to repair the infarcted myocardium in a rabbit model. CBD-VEGF/collagen group could effectively induce more cells to penetrate into the collagen membrane after 4 weeks and promote more vascularization in infarcted myocardium after 12 weeks compared with the other two control groups. Echocardiography and hemodynamic studies both show cardiac function improvement in the CBD-VEGF/collagen group. These results reveal that implantation of CBD-VEGF collagen membrane patch into the infarcted myocardium could effectively improve left ventricle cardiac function and increase the vascular density.     

PDGF-BB、IL-13和TGF-β1诱导真皮成纤维细分泌Ⅰ型胶原蛋白的比较

目的用不同浓度的白介素13(IL-13)、转化生长因子β1(TGF-β1)和血小板源性生长因子BB(PDGF-BB)在体外诱导真皮成纤维细胞,以甄选促进诱导Ⅰ型胶原蛋白高分泌的细胞因子。方法选用出生2d的SD大鼠背部皮肤进行真皮成纤维细胞原代培养,采用免疫荧光技术对其进行纯度鉴定。实验分为4组:PDGF-BB(30ng/mL)组、IL-13(100ng/m)组、TGF-β1(10ng/mL)组和不加任何处理因素的阴性对照组,用MTT法、ELISA检测在24h、48h、72h时的真皮成纤维细胞的增殖情况及培养液中Ⅰ型胶原蛋白的浓度。结果原代培养真皮成纤维细胞的纯度达90%以上。PDGF-BB、IL-13、TGF-β1均能促进真皮成纤维细胞增殖和Ⅰ型胶原蛋白分泌,在48h、72h时PDGF-BB组的培养液中Ⅰ型胶原蛋白浓度明显高于IL-13组、TGF-β1组及阴性对照组(P<0.05)。结论浓度为30ng/mL的PDGF-BB促进真皮成纤维细胞增殖和分泌Ⅰ型胶原蛋白的作用更为显著。     

Accelerated healing of ulcer wounds in the rabbit ear by recombinant human transforming growth factor-beta 1

A dermal ulcer wound-healing model was established in rabbit ear to examine the effects of recombinant human transforming growth factor-beta 1 (rhTGF-beta 1) in wound healing. Histomorphometric examination of the wounds indicate a biphasic healing response 7 days after a single application of rhTGF-beta 1 at the time of wounding. Statistically significant healing occurred at 5-100 ng but not at higher doses of 500 or 1000 ng rhTGF-beta 1/wound. Enhanced collagen synthesis as determined by [3H]proline incorporation occurred at 15 and 25 ng and was significantly depressed at 500 ng rhTGF-beta 1/wound. Multiple doses of 100 ng rhTGF-beta 1 applied to the wound at the time of wounding and for 3 days after wounding provided results comparable to the single application of growth factor. Delaying treatment 24 hr after wounding did not enhance wound healing compared with vehicle. Our findings suggest that rhTGF-beta 1 can be a valuable growth factor to improve the healing of ulcer wounds.     

Dual delivery of chlorhexidine and platelet-derived growth factor-BB for enhanced wound healing and infection control

Wound treatment can require molecules that both enhance healing and control infection. As in many biomedical applications, the options for therapeutic molecules may include both hydrophilic and hydrophobic molecules. The goal of this study was to investigate a polymer system for drug delivery that simultaneously delivers platelet-derived growth factor (PDGF)-BB, a hydrophilic protein known to promote wound healing, and chlorhexidine (CHX), a hydrophobic antimicrobial agent for infection treatment. Poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared using different polymer formulations in a double emulsion process. CHX encapsulation efficiency was 19.6 ± 0.8% and 28.9 ± 1.5% for PLGA 50:50 and 85:15, respectively. The presence of CHX significantly increased PDGF-BB encapsulation efficiency relative to PDGF-BB alone. Both molecules could be released for up to 50 days and exhibited bioactivity for greater than 3 (PLGA 85:15) or 8 (PLGA 50:50) weeks using in vitro bacteria and cellular assays. An infected wound model was used to evaluate the system in vivo. Wounds treated with the dual delivery system showed decreased levels of infection and increased healing. Vascular analysis of wound tissues also showed higher levels of mature vasculature with the delivery of PDGF-BB. In conclusion, we have evaluated a drug delivery system for simultaneous delivery of hydrophobic and hydrophilic molecules and have shown that this system can improve healing and reduce bacteria levels in an infected wound model. This system could be applied to other therapeutic applications where sustained delivery of hydrophobic and hydrophilic molecules is required.     

bFGF and PDGF-BB for Tendon Repair: Controlled Release and Biologic Activity by Tendon Fibroblasts <Emphasis Type="Italic">In Vitro</Emphasis>

Flexor tendon injuries are often encountered clinically and typically require surgical repair. Return of function after repair is limited due to adhesion formation, which leads to reduced tendon gliding, and due to a lack of repair site strength, which leads to repair site gap formation or rupture. The application of the growth factors basic fibroblastic growth factor (bFGF) and platelet derived growth factor BB (PDGF-BB) has been shown to have the potential to enhance tendon healing. The objectives of this study were to examine: (1) the conditions over which delivery of bFGF can be controlled from a heparin-binding delivery system (HBDS) and (2) the effect of bFGF and PDGF-BB released from this system on tendon fibroblast proliferation and matrix gene expression in vitro over a 10-day interval. Delivery of bFGF was controlled using a HBDS. Fibrin matrices containing the HBDS retained bFGF better than did matrices lacking the delivery system over the 10-day period studied. Delivery of bFGF and PDGF-BB using the HBDS stimulated tendon fibroblast proliferation and promoted changes in the expression of matrix genes related to tendon gliding, strength, and remodeling. Both growth factors may be effective in enhancing tendon healing in vivo.     

Enhancement of PDGF-BB mitogenic activity on human dermal fibroblasts by biospecific dextran derivatives

Dextran derivatives are biosynthetic polyanionic polymers which exert some of the heparin properties such as regulating the activity of several heparin-binding growth factors. Based on a reproducible synthetic procedure, we have synthesized a new generation of dextran derivatives named dextran methylcarboxylate benzylamide sulfate (DMCBSu). Here we investigated the ability of a library of well-characterized DMCBSu to interact with platelet-derived growth factor-BB (PDGF-BB), which has essential roles during wound healing. Using gel mobility shift assay, our results indicate that benzylamide and sulfate groups act synergically to bind to PDGF-BB. Furthermore we show that depending on their chemical composition, functionalized dextrans are able to potentiate the mitogenic activity of PDGF-BB on human dermal fibroblasts. This enhancing effect is accompanied with changes in PDGF-BB-induced signaling events, as determined by the use of specific inhibitors and by western blot. Our results suggest that the use of such biopolymers combined with a local administration of the growth factor could increase the efficiency of the biomolecule activity in future therapeutic strategies.     

Dextran derivatives modulate collagen matrix organization in dermal equivalent

Dextran derivatives can protect heparin binding growth factor implied in wound healing, such as transforming growth factor-β1 (TGF-β1) and fibroblast growth factor-2 (FGF-2). The first aim of this study was to investigate the effect of these compounds on human dermal fibroblasts in culture with or without TGF-β1. Several dextran derivatives obtained by substitution of methylcarboxylate (MC), benzylamide (B) and sulphate (Su) groups were used to determine the effects of each compound on fibroblast growth in vitro. The data indicate that sulphate groups are essential to act on the fibroblast proliferation. The dextran derivative LS21 DMCBSu has been chosen to investigate its effect on dermal wound healing process. Fibroblasts cultured in collagenous matrices named dermal equivalent were treated with the bioactive polymer alone or associated to TGF-β1 or FGF-2. Cross-sections of dermal equivalent observed by histology or immunohistochemistry, demonstrated that the bioactive polymer accelerates the collagen matrices organization and stimulates the human type-III collagen expression. This bioactive polymer induces apoptosis of myofibroblast, property which may be beneficial in treatment of hypertrophic scar. Culture media analyzed by zymography and Western blot showed that this polymer significantly increases the secretion of zymogen and active form of matrix metalloproteinase-2 (MMP-2), involved in granulation tissue formation. These data suggest that this bioactive polymer has properties which may be beneficial in the treatment of wound healing.     

Promotion of angiogenesis by sustained release of rhGM-CSF from heparinized collagen/chitosan scaffolds

A novel dermal substitute of combining recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) with a porous heparinized collagen/chitosan scaffolds was developed, considering the inadequate angiogenesis during repair of full-thickness skin defects. The physicochemical properties of heparinized collagen/chitosan scaffolds were examined and in vitro release pattern of rhGM-CSF from scaffolds was measured by ELISA. Four groups of composite scaffolds (heparinized or unheparinized scaffolds loaded with or without rhGM-CSF) were fabricated for subcutaneous implantation in young adult male Sprague-Dawley (SD) rats. Tissue specimens were harvested at different time points after implantation for histopathological, immunohistochemical observation, and Western blotting analysis. The heparinized scaffolds (H(1)E) showed slower biodegradation and sustained release of rhGM-CSF in vitro, although no significantly different release pattern was observed between the H(1)E and unheparinized scaffolds (H(0)E). In vivo investigation revealed that the heparinized scaffolds loaded with rhGM-CSF (H(1)E/rhGM-CSF) had the best cellular adhesion and migration, new vessel formation, and highest expression of VEGF and TGF-β1, indicating promoted angiogenesis. This study demonstrated that composite dermal substitute of combining rhGM-CSF with a porous heparinized collagen/chitosan scaffolds could be a potential therapeutic agent for full-thickness skin defects because of its sustained delivery of rhGM-CSF.     

Molded porous poly (L-lactide) membranes for guided bone regeneration with enhanced effects by controlled growth factor release

The aim of this study was to develop platelet-derived growth factor (PDGF-BB) loaded moldable porous poly (L-lactide) (PLLA)-tricalcium phosphate (TCP) membranes for guided bone regeneration (GBR) therapy. The membranes were designed to fit various types of bone defect sites. PDGF-BB-dissolved PLLA-TCP in methylene chloride-ethyl acetate solution was cast on a dome shaped metallic mold to fabricate a model membrane. The release rate of PDGF-BB, the osteoblast attachment test, and guided bone regeneration potential were evaluated with PDGF-BB-loaded PLLA-TCP membranes. Regular pores were generated throughout the membrane mainly due to phase inversion of PLLA-methylene chloride-ethyl acetate solution. A therapeutic amount of PDGF-BB was released from the membrane. The release rate could be controlled by varying the initial loading content of PDGF-BB. A significant amount of cells attached onto the PDGF-BB-loaded membrane rather than onto the unloaded membrane. Dome shaped bone formation was achieved in rabbit calvaria at 4 weeks. This indicated that restoration of bone defects to the bone's original shape can be made possible by using molded membranes, which guide bone regeneration along with providing sufficient spaces. Bone forming efficiency was increased remarkably due to PDGF-BB release from PLLA-TCP membranes. These results suggested that the PDGF-BB releasing molded PLLA-TCP membrane may potentially improve GBR efficiency in various types of bone defects.     

Overexpression of Lysyl Oxidase to Increase Matrix Crosslinking and Improve Tissue Strength in Dermal Wound Healing

In this study, we aimed to increase crosslinking in collagen and elastin in the extracellular matrix through overexpression of lysyl oxidase (LO) in order to improve mechanical strength in dermal wounds during healing. We had used a gene activated matrix (GAM) approach to locally deliver plasmid DNA (pDNA) complexed with polyethylenimine (PEI) in collagen gels at the wound site for localized and sustained transfection of cells involved in the healing process. We first demonstrated in vitro that PEI-pDNA complexes in collagen gels could be taken up and expressed by cultured fibroblasts for at least 20 days. In vitro studies showed that fibroblast-seeded GAMs with the LO transgene exhibited over a 3-fold increase in mechanical strength as compared with a green fluorescent protein (GFP)-transgene control. Addition of an inhibitor of LO abolished this increase. We applied this system in a rat dermal wound healing model and showed that treatment with LO-producing GAMs led to significantly enhanced mechanical strength of the wound site.     

Accelerated Healing of Ulcer Wounds in the Rabbit Ear by Recombinant Human Transforming Growth Factor-β1

Abstract

A dermal ulcer wound-healing model was established in rabbit ear to examine the effects of recombinant human transforming growth factor-β1 (rhTGF-β 1) in wound healing. Histo-morphometric examination of the wounds indicate a biphasic healing response 7 days after a single application of rhTGF-β l at the time of wounding. Statistically significant healing occurred at 5-100 ng but not at higher doses of 500 or 1000 ng rhTGF-β l/wound. Enhanced collagen synthesis as determined by [³H] proline incorporation occurred at 15 and 25 ng and was significantly depressed at 500 ng rhTGF-β1wound. Multiple doses of 100 ng rhTGF-/3l applied to the wound at the time of wounding and for 3 days after wounding provided results comparable to the single application of growth factor. Delaying treatment 24 hr after wounding did not enhance wound healing compared with vehicle. Our findings suggest that rhTGF-β l can be a valuable growth factor to improve the healing of ulcer wounds.     

Platelet-derived growth factor-BB and transforming growth factor beta 1 selectively modulate glycosaminoglycans, collagen, and myofibroblasts in excisional wounds.

Recombinant platelet-derived growth factor (PDGF) and transforming growth factor beta 1 (TGF-beta 1) influence the rate of extracellular matrix formed in treated incisional wounds. Because incisional healing processes are difficult to quantify, a full-thickness excisional wound model in the rabbit ear was developed to permit detailed analyses of growth-factor-mediated tissue repair. In the present studies, quantitative and qualitative differences in acute inflammatory cell influx, glycosaminoglycan (GAG) deposition, collagen formation, and myofibroblast generation in PDGF-BB (BB homodimer)- and TGF-beta 1-treated wounds were detected when analyzed histochemically and ultrastructurally. Although both growth factors significantly augmented extracellular matrix formation and healing in 10-day wounds compared with controls (P less than 0.002). PDGF-BB markedly increased macrophage influx and GAG deposition, whereas TGF-beta 1 selectively induced significantly more mature collagen bundles at the leading edge of new granulation tissue (P = 0.007). Transforming growth factor-beta 1-treated wound fibroblasts demonstrated active collagen fibrillogenesis and accretion of subfibrils at the ultrastructural level. Myofibroblasts, phenotypically modified fibroblasts considered responsible for wound contraction, were observed in control, but were absent in early growth-factor-treated granulating wounds. These results provide important insights into the mechanisms of soft tissue repair and indicate that 1) PDGF-BB induces an inflammatory response and provisional matrix synthesis within wounds that is qualitatively similar but quantitatively increased compared with normal wounds; 2) TGF-beta 1 preferentially triggers synthesis and more rapid maturation of collagen within early wounds; and 3) both growth factors inhibit the differentiation of fibroblasts into myofibroblasts, perhaps because wound contraction is not required, due to increased extracellular matrix synthesis.     

Growth Factors in Gastrointestinal Diseases

This review focuses on the recent investigations demonstrating a pharmacological and pathophysiological role for basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) in ulcerative and inflammatory lesions in the upper and lower gastrointestinal (GI) tract. Our initial experiments revealed that intragastric administration of bFGF-w, acid-resistant bFGF-CS23 and PDGF-BB healed chronic cysteamine (mercaptamine)-induced duodenal ulcer in rats, without decreasing gastric acid secretion or concentration. Subsequently we and others have demonstrated that these peptides accelerate the healing of chronic gastric ulcers, chronic erosive gastritis and ulcerative colitis although they have no or modest acute gastric protective activity. Our recent results revealed a decreased bioactivity of bFGF and PDGF in the presence of certain strains of Helicobacter pylori, and this might explain, at least in part, the poor rates of ulcer healing in H. pylori-positive patients. VEGF, in addition to stimulating angiogenesis and granulation tissue production in duodenal ulcer healing, also has an acute gastroprotective effect. New biochemical, molecular biological and immunohistochemical studies indicate that bFGF, PDGF and VEGF play a pathophysiological role in the natural history of ulcer healing. Thus, growth factor research, especially regarding their possible use as a therapeutic tool in duodenal ulcer and colitis, is challenging. On the other hand, in some GI malignancies the diagnostic use of bFGF might be of clinical benefit. However, much research work is needed to transform these 'endogenous drugs' to 'diagnostic tools' and 'exogenous drugs'.     

Dextran derivatives modulate collagen matrix organization in dermal equivalent

Dextran derivatives can protect heparin binding growth factor implied in wound healing, such as transforming growth factor-beta1 (TGF-beta1) and fibroblast growth factor-2 (FGF-2). The first aim of this study was to investigate the effect of these compounds on human dermal fibroblasts in culture with or without TGF-beta1. Several dextran derivatives obtained by substitution of methylcarboxylate (MC), benzylamide (B) and sulphate (Su) groups were used to determine the effects of each compound on fibroblast growth in vitro. The data indicate that sulphate groups are essential to act on the fibroblast proliferation. The dextran derivative LS21 DMCBSu has been chosen to investigate its effect on dermal wound healing process. Fibroblasts cultured in collagenous matrices named dermal equivalent were treated with the bioactive polymer alone or associated to TGF-beta1 or FGF-2. Cross-sections of dermal equivalent observed by histology or immunohistochemistry, demonstrated that the bioactive polymer accelerates the collagen matrices organization and stimulates the human type-III collagen expression. This bioactive polymer induces apoptosis of myofibroblast, property which may be beneficial in treatment of hypertrophic scar. Culture media analyzed by zymography and Western blot showed that this polymer significantly increases the secretion of zymogen and active form of matrix metalloproteinase-2 (MMP-2), involved in granulation tissue formation. These data suggest that this bioactive polymer has properties which may be beneficial in the treatment of wound healing.     

重组人Ⅲ型胶原蛋白水凝胶对猪全层皮肤缺损创面修复的影响

目的观察重组人Ⅲ型胶原蛋白水凝胶用于治疗猪全层皮肤缺损创面，在创面愈合和血管新生，新生真皮胶原排列状态和胶原比例等方面的影响。 方法将重组人Ⅲ型胶原蛋白粉末与海藻酸钠粉末以质量比10∶1混合，溶于无菌磷酸盐缓冲液中，制备成胶原蛋白含量为10%的溶液，使用时以10% Ca^2＋溶液交联成凝胶状。以巴马小型猪作为实验动物制备动物模型，在每头猪背部正中线两侧旁开2 cm分别用手术刀制备3个边长5 cm深达肌肉筋膜的正方形全层皮肤缺损创面，采用同体自身对照，实验组用重组人Ⅲ型胶原蛋白水凝胶治疗，水凝胶外层覆盖无菌硅胶膜保湿；阳性对照组用可吸收性敷料治疗；阴性对照组仅用无菌硅胶膜覆盖。术后7、14、21、90 d，进行创面大体观察，并取材行苏木精-伊红染色，光学显微镜下观察创面修复情况、炎症反应，免疫组织化学染色法检测创面CD31的表达并计数新生血管数目，天狼猩红饱和苦味酸染色偏振光观察胶原纤维排列、Ⅲ型胶原蛋白比例。实验数据比较采用单因素方差分析、SNK-q检验或Kruskal Wallis H检验。 结果实验组创面肉芽组织平整，颜色鲜红，柔软湿润。光学显微镜下见实验组较阴性对照组组织炎症反应轻微，创面修复早期肉芽组织生长速度快。CD31免疫组织化学染色结果显示，术后7、14、21 d，实验组新生毛细血管数分别为(18.8±2.7)、(32.0±4.4)、(42.8±4.5)个/ hpf，而阴性对照组仅分别为(12.0±3.0)、(16.6±2.3)、(12.6±4.1)个/ hpf，各个时间点实验组新生毛细血管数均高于阴性对照组，差异均有统计学意义(P值均小于0.05)。术后14、21、90 d创面新生真皮组织天狼猩红饱和苦味酸染色结果显示，实验组较阴性对照组胶原纤维排列规整，与阳性对照组相似，而Ⅲ型胶原蛋白比例较阴性和阳性对照组均升高。 结论重组人Ⅲ型胶原蛋白水凝胶可促进全层创面愈合和血管新生，促进新生真皮组织胶原纤维有序排列，增加Ⅲ型胶原在新生真皮胶原中所占比例，从而改善创面愈合质量，并有望减轻创面愈合后的瘢痕形成。     

Evaluation of adhesion, proliferation, and functional differentiation of dermal fibroblasts on glycosaminoglycan-coated polysulfone membranes

It may be hypothesized that wound healing will benefit from polymer membranes coated with extracellular matrix macromolecules. Here we describe the behavior of dermal fibroblasts on polysulfone (PSU) membranes, and PSU membranes covered with chitosan (Ch), chondroitin sulfate (CS), or hyaluronan, using an additional intermediary ionic charge modification with poly-(acrylonitrile-co-methallyl sulfonate) (AN69), which allows binding of the polysaccharidic macromolecules. Cell adhesion, proliferation, cell signaling, and collagen gene expression were investigated. Ch and CS were found unable to support cell adhesion and proliferation. In contrast, both PSU and hyaluronic acid-coated PSU membranes appeared as suitable materials to culture fibroblasts and support their matrix synthesis capacity. Moreover, they induce type III collagen expression in addition to type I, suggesting that they promote a fetal-like environment that could be beneficial for wound healing.