Peroxide‐based oxygen generating topical wound dressing for enhancing healing of dermal wounds

Oxygen generating biomaterials represent a new trend in regenerative medicine that aims to generate and supply oxygen at the site of requirement, to support tissue healing and regeneration. To enhance the healing of dermal wounds, we have developed a highly portable, in situ oxygen generating wound dressings that uses sodium percarbonate (SPO) and calcium peroxide (CPO) as chemical oxygen sources. The dressing continuously generated oxygen for more than 3 days, after which it was replaced. In the in vivo testing on porcine full‐thickness porcine wound model, the SPO/CPO dressing showed enhanced wound healing during the 8 week study period. Quantitative measurements of wound healing related parameters, such as wound closure, reepithelialization, epidermal thickness and collagen content of dermis showed that supplying oxygen topically using the SPO/CPO dressing significantly accelerated the wound healing. An increase in neovascularization, as determined using Von Willebrand factor (vWF) and CD31 staining, was also observed in the presence of SPO/CPO dressing. This novel design for a wound dressing that contains oxygen generating biomaterials (SPO/CPO) for supplying topical oxygen, may find utility in treating various types of acute to chronic wounds.     

Efficacy of Jasminum grandiflorum L. leaf extract on dermal wound healing in rats

Wound healing is a fundamental response to tissue injury and natural products accelerate the healing process. Here, we have explored the efficacy of topical administration of an ointment, prepared by methanolic extract of Jasminum grandiflorum L. (Oleaceae) leaves, on cutaneous wound healing in rats. The topical application of the Jasminum ointment on full thickness excision wounds accelerated the healing process. Tissue growth and collagen synthesis were significantly higher determined by total hydroxyl proline, hexosamine, protein and DNA content. The response was concentration‐ and time‐dependent, when observed on days 4, 8 and 12 after wound creation. The rate of wound healing was faster as determined by wound contraction, tensile strength and other histopathological changes. In addition, this ointment also raised the activity of superoxide dismutase (SOD) and catalase (CAT) with high GSH content and low lipid peroxidation products in wound tissue. Thus, it could be suggested that the ointment from the methanolic extract of J. grandiflorum leaf improves the rate of wound healing by enhancing the rate of collagen synthesis and also by improving the antioxidant status in the newly synthesised healing wound tissue.     

EGF increases short-term type I collagen accumulation during wound healing in diabetic rats

Continuous topical application of epidermal growth factor (EGF) to granulation tissue increases the rate of collagen accumulation. It is believed that the clinical use of growth factors, such as EGF, may become common in the treatment of impaired wound healing in the near future. Impairments in the production and degradation of wound collagens have been demonstrated in diabetes mellitus. We studied the effects of a single, local application of EGF on collagen content, collagenase activity, and the ratio of type III and type I collagens within granulation tissue using polytetrafluoroethylene (PTFE) wound cylinders in 48 streptozotocin-induced diabetic rats in order to determine potential benefits of EGF to wound healing in diabetics. Wound collagen content in EGF-treated diabetic animals was significantly higher than in diabetic controls during the first 10 days of wound healing (236% on day 5, P less than .001; 140% on day 10, P less than .01), but decreased to significantly lower levels by day 15 of healing (71% of diabetic controls, P less than .01; 47% of nondiabetic controls, P less than .01). An 18% increase in diabetic wound protease activity was observed following application of EGF (P less than .001). The ratio of type III collagen to total wound collagen within the granulation tissue was significantly reduced (P less than .001) following EGF application. We demonstrate that a single, topical application of EGF promotes early synthesis of type I collagen, thereby deranging the usual type III/total collagen ratio, and is associated with increased wound protease activity.     

Oxidant and antioxidant events during epidermal growth factor therapy to cutaneous wound healing in rats

Cutaneous wound healing is a highly complex process, which includes inflammation, cell proliferation, matrix deposition and remodelling phases. Various growth factors, like epidermal growth factor (EGF), play an important role during wound healing. However, little is known about relationship between EGF and oxidant-antioxidant events in cutaneous wound healing models. Thus we planned to evaluate the connection between EGF therapy and oxidative stress in dermal tissue followed by wounding. Fifty-four adult male Wistar-albino rats were randomly divided into three groups: control, untreated and topical EGF administrated group. A linear full-thickness excision of 40 mm in length on both sides of spinal cord was made on the back of each rat and sutured under anaesthesia and sterile conditions. Excision was closed with 4/0 atraumatic silk suture. EGF solution was freshly prepared at 10 ng/ml dose in thilotears gel under aseptic conditions. Following the surgery, 1 ml of EGF solution was administered to wound strips one time in everyday. The animals were euthanised and wound tissues were collected on days 1, 5, 7 and 14. Thiobarbituric acid reactive substans (TBARS), glutathione (GSH), reactive nitrogen oxide species (NOx), ascorbic acid levels and superoxide dismutase activity were measured spectrophotometrically. TBARS levels decreased and NOx levels increased on day 5 after operation, and GSH levels were increased on day 14 in EGF administered group compared with untreated group. Our data showed that EGF may act like an antioxidant by scavenging toxic oxidation products in wound tissue. In addition, it may contribute healing of the wound tissue in earlier stages and suggest a potential effective role for antioxidant therapies, especially until day 5.     

Streptolysin O enhances keratinocyte migration and proliferation and promotes skin organ culture wound healing in vitro

ML-05, a modified form of the hemolytic and cytotoxic bacterial toxin, streptolysin O, is currently being investigated as a treatment for collagen-related disorders such as scleroderma and fibrosis. Furthermore, ML-05 may be effective in promoting wound healing and alleviating the formation of hypertrophic scars and keloids. To investigate the effects of ML-05 on wound-healing processes, in vitro wound-healing scratch assays (using human primary epidermal keratinocytes and dermal fibroblasts) and a human skin organ culture wound model were utilized. ML-05 markedly enhanced keratinocyte migration and proliferation in wound scratch assays. ML-05 did not affect either proliferation or migration of dermal fibroblasts, indicating that ML-05's effects on cell migration/proliferation may be keratinocyte-specific. ML-05 was tested in a dose-dependent manner in a skin organ culture wound model using two different application methods: Through the culture media (dermal exposure) or direct topical treatment of the wound surface. ML-05 was found to accelerate wound healing as measured by reepithelialization, particularly after topical application. Therefore, ML-05 may have potential as a wound-healing agent that promotes reepithelialization through stimulation of keratinocyte migration and proliferation.     

Effects of plasma fibronectin on the healing of full-thickness skin wounds in streptozotocin-induced diabetic rats

BACKGROUND: Fibronectin has been shown to assist in wound healing. Impaired wound healing in diabetes mellitus is characterized by a reduction in plasma fibronectin (pFn) at the wound site. This study investigated whether topical application of pFn could improve the impaired wound healing in diabetic rats. MATERIALS AND METHODS: Full-thickness skin wounds were created on the backs of streptozotocin (STZ)-induced diabetic rats. Immediately, human pFn was introduced into the wound bed, while wounds receiving human serum albumin or normal saline were used as controls. Wound closure was monitored using well-recognized wound-healing parameters: epithelialization, vascularization, collagen deposition, and migration of fibroblasts were examined histologically. Transforming growth factor (TGF)-beta1 was measured by immunochemistry. Hydroxyproline levels also were assessed in the wound skin. RESULTS: Wound closure was significantly accelerated by local application of pFn. Furthermore, pFn-treated wounds showed increased fibroblast vascularization, collagen regeneration, and epithelialization. The numbers of infiltrating fibroblasts expressing TGF-beta1 and hydroxyproline levels in pFn-treated wounds were significantly higher than those in the controls. CONCLUSIONS: pFn can improve the impaired healing of diabetic wounds and this effect might involve an increase in the activity of fibroblasts and increased release of TGF-beta1.     

Ultrastructural analysis of fetal rabbit wounds

Fetal wound healing proceeds rapidly with minimal inflammation and fibroplasia and little or no scar formation. These observations have led to the hypothesis that fetal wound healing more closely resembles regeneration rather than adult wound repair. To test this hypothesis, this study used ultrastructural analysis of fetal and adult fibroblasts and collagen to gain greater insight into differences in the healing processes. Full-thickness, primarily closed linear incisions were created dorsally on 24-day gestational age fetal rabbits (n = 9). The fetuses were killed 5 days later, and the wounds were excised and evaluated with transmission electron microscopy. Similarly, uninjured fetal skin of the same gestational age was obtained and analyzed. Adult rabbit dermal wounds were analyzed after 8 days of healing. Resting adult dermal fibroblasts had features of quiescent, inactive cells, whereas adult wound fibroblasts were highly active and filled with secretory vesicles. In contrast, both fetal normal dermal and wound fibroblasts appeared highly active and contained numerous secretory vesicles. In the adult wound, collagen fibril diameter was only 45% of the diameter of normal dermal collagen. However, fetal wound collagen fibrils were basically the same as normal dermal collagen, having a diameter that was 82% of the size of dermal collagen. These observations suggest that fetal wound fibroblasts do not require activation from an inactivated state and that fetal wound collagen deposition undergoes more rapid organization and maturation. These findings have significance in extending our understanding of the rapidity and functional superiority of fetal wound healing compared with adult wound healing.     

Endogenous Growth Factors as Cosmeceuticals

Background. Research into the pathophysiology of photodamaged skin has revealed correlations with certain aspects of acute and chronic wound healing. In wound healing, growth factors accumulate at the wound site and interact synergistically to initiate and coordinate wound healing.
Objectives. To review the effects of topical growth factors in wound healing and their potential use in treating photodamaged skin.
Methods. A mixture of multiple growth factors derived from human fibroblasts was applied topically to 14 patients twice daily for 60 days to stimulate the remodeling phase of wound healing.
Results. A total of 78.6% of patients with photodamaged skin showed clinical improvement at 60 days. New collagen formation increased by 37%, and epidermal thickening increased by 27%.
Conclusions. These data, as well as other studies of growth factors in wound healing, demonstrate positive cosmetic and clinical outcomes of topical application of growth factors for the treatment of photodamaged skin.
DR. FITZPATRICK IS THE FOUNDER OF SKIN MEDICA AND OWNS STOCK AS WELL AS STOCK OPTIONS.     

NF-κB and COX-2 repression with topical application of hesperidin and naringin hydrogels augments repair and regeneration of deep dermal wounds

IntroductionWound injury is common and causes serious complications if not treated properly. The moist dressing heals wounds faster than other dressings. Therefore, we sought to study the effect of hesperidin/naringin hydrogel wound dressing or their combinations on the deep dermal wounds in mice.MethodsA rectangular full thickness skin flap of 2.5 × 1.5 cm was excised from depilated mice dorsum and the wound was fully covered with 5% hesperidin/5% naringin hydrogel or both in the ratio of 1:1, 2:1, or 1:2, respectively once daily until complete healing of the wound. Data were collected on wound contraction, mean wound healing time, collagen, DNA, and nitric oxide syntheses, glutathione concentration, superoxide dismutase activity, and lipid peroxidation throughout healing. Expression of NF-κB and COX-2 were also estimated in the regenerating granulation tissue using Western blot.FindingsDressing of wounds with 5% hesperidin hydrogel led to a higher and early wound contraction and significantly reduced mean wound healing time by 5.7 days than 5% naringin or combination of hesperidin and naringin hydrogels in the ratio of 1:1, 2:1, or 1:2. Hesperidin hydrogel wound dressing caused higher collagen and DNA syntheses than other groups at all times after injury. Glutathione concentration and superoxide dismutase activity increased followed by a decline in lipid peroxidation in regenerating wounds after hesperidin/naringin hydrogel application and a maximum effect was observed for hesperidin alone. The hesperidin/naringin hydrogel suppressed NF-κB and COX-2 expression on days 6 and 12.ConclusionsApplication of 5% hesperidin hydrogel was more effective than 5% naringin or combination of hesperidin and naringin gels (1:1, 2:1 or 1:2) indicated by a greater wound contraction, reduced mean wound healing time, elevated collagen and DNA syntheses, rise in glutathione concentration, and superoxide dismutase activity followed by reduced lipid peroxidation, and NF-κB, and COX-2 expression.     

ß2-adrenergic receptor activation delays dermal fibroblast-mediated contraction of collagen gels via a cAMP-dependent mechanism

Dermal fibroblasts actively contribute to wound healing by migrating to the wound, synthesizing extracellular matrices, and generating mechanical forces within the wound to initiate wound contraction. Fibroblast-seeded collagen gels provide an in vitro model to study wound contraction. The authors are evaluating the role of the adrenergic signaling system in cutaneous wound repair and recently found that beta2-adrenergic receptor (beta2-AR) activation markedly decreases keratinocyte migration, an essential step in wound reepithelialization. Because the beta2-ARs are also expressed on dermal fibroblasts, a study was initiated to determine the effects of beta-adrenergic agonists on dermal fibroblast-mediated collagen gel contraction. A beta-agonist (isoproterenol) delayed gel contraction in a dose-dependent manner. A beta2-AR specific antagonist (ICI 118,551) prevented the delay, indicating that the beta2-AR alone mediated the delay. The active cyclic adenosine monophosphate (cAMP) analog also delayed collagen gel contraction, whereas an inactive cAMP analog partially prevented the delay, suggesting that the mechanism for beta-AR agonist-mediated delay was partly cAMP-dependent. Identifying and characterizing agents that modulate wound contraction improves understanding of the wound healing process and could result in novel therapeutic strategies for preventing unwanted wound contraction in burn and trauma patients.     

表皮生长因子对大鼠深Ⅱ度烧伤创面愈合的影响

目的　进一步观察重组人表皮生长因子 (rhEGF)对深Ⅱ度烧伤创面愈合的促进作用。方法　采用大鼠深Ⅱ度烫伤模型 (以下称烧伤 ) ,创面分别外用rhEGF、肝素加rhEGF及等渗盐水。比较不同方式处理创面后的愈合时间 ,测定创面愈合率、创面含水量、羟脯氨酸 (OHP)含量及Ⅰ /Ⅲ型胶原比例 ,进行细胞DNA周期分析和组织学检查。　结果　外用rhEGF可使烧伤创面愈合时间缩短 2d,增加创面OHP含量 (P <0.0 5),降低Ⅰ /Ⅲ型胶原比例 (P <0.0 5),促进肉芽组织形成 ,加速细胞DNA复制 (P <0.0 5 )。加用肝素后可使创面愈合时间进一步缩短 2d,促进肉芽组织生长。伤后第 7天用药各组间比较 ,差异无显著性意义 (P >0.0 5)。　结论　外用rhEGF能明显促进深Ⅱ度烧伤创面愈合 ,加用肝素后效果更加显著 ,但早期使用rhEGF效果不明显     

Liposomal gene transfer of keratinocyte growth factor improves wound healing by altering growth factor and collagen expression

BACKGROUND: Growth factors affect the complex cascade of wound healing; however, interaction between different growth factors during dermal and epidermal regeneration are still not entirely defined. In the present study, we thought to determine the interaction between keratinocyte growth factor (KGF) administered as liposomal cDNA with other dermal and epidermal growth factors and collagen synthesis in an acute wound. MATERIALS AND METHODS: Rats received an acute wound and were divided into two groups to receive weekly subcutaneous injections of liposomes plus the Lac-Z gene (0.22 microg, vehicle), or liposomes plus the KGF cDNA (2.2 microg) and Lac-Z gene (0.22 microg). Histological and immunohistochemical techniques were used to determine growth factor, collagen expression, and dermal and epidermal structure. RESULTS: KGF cDNA increased insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3), and fibroblast growth factor (FGF), decreased transforming growth factor-beta (TGF-beta), while it had no effect on platelet-derived growth factor (PDGF) levels in the wound. KGF cDNA significantly increased collagen Type IV at both the wound edge as well as the wound bed, while it had no effect on collagen Type I and III. KGF cDNA increased re-epithelialization, improved dermal regeneration, and increased neovascularization. CONCLUSIONS: Exogenous administered KGF cDNA causes increases in IGF-I, IGF-BP3, FGF, and collagen IV and decreases TGF-beta concentration. KGF gene transfer accelerates wound healing without causing an increase in collagen I or III.     

Bone marrow-derived cells in the healing burn wound--more than just inflammation

Scarring after severe burn is a result of changes in collagen deposition and fibroblast activity that result in repaired but not regenerated tissue. Re-epithelialisation of wounds and dermal cell repopulation has been thought to be driven by cells in the periphery of the wound. However, recent research demonstrated that cells originating from the bone marrow contribute to healing wounds in other tissues and also after incisional injury. We investigated the contribution of bone marrow-derived cells to long-term cell populations in scar tissue (primarily fibroblasts and keratinocytes) after severe burn. Wild-type mice were lethally irradiated and then the bone marrow reconstituted by injection of chimeric bone marrow cells expressing EGFP marker protein. Mice with chimeric bone marrow were then given a burn, either an 1-cm diameter injury (to mimic minor injury) or 2-cm diameter (to mimic moderate injury). Wounds were analysed at days 1, 3, 7, 14, 21, 28, 56 and 120 using FACS and immunohistochemistry to identify the percentage and cell type within the wound originating from the bone marrow. The inflammatory cell infiltrate at the early time-points was bone marrow in origin. At later time-points, we noted that over half of the fibroblast population was bone marrow-derived; we also observed that a small percentage of keratinocytes appeared to be bone marrow in origin. These findings support the theory that the bone marrow plays an important role in providing cells not only for inflammation but also dermal and epidermal cells during burn wound healing. This increases our understanding of cell origins in the healing wound, and has the potential to impact on clinical practice providing a potential mechanism for intervention away from conventional topical treatments and directed instead to systemic treatments affecting the bone marrow response.     

无机活性元素对皮肤创面愈合的生物诱导作用

目的观察并论证无机活性元素(商品名德莫林)对上皮细胞增殖、分化的诱导作用以及对皮肤创面愈合的促进作用。方法(1)细胞实验:将正常人皮肤上皮细胞分为实验组(培养液中含20g/L德莫林)和对照组(常规培养)。培养12、20d时检测两组细胞的增殖倍数以及培养上清液中Ⅳ型胶原和表皮生长因子(EGF)的含量。(2)动物实验:在60只SD大鼠背部制作对称性的10%TBSA浅Ⅱ、深Ⅱ度烫伤创面(各30只60个)。采用自身同体对照法,治疗组创面用1g/100cm2德莫林治疗,对照组创面常规涂抹磺胺嘧啶银(SD-Ag)冷霜。观察治疗3、5、7、10、14、18d时创面皮肤的病理学改变并计算创面愈合率。(3)临床应用:采用随机、双盲、同体对照法,选择浅Ⅱ、深Ⅱ度烧伤创面和供皮区创面各30例60个,治疗组创面用1g/100cm2德莫林治疗,对照组创面常规应用碘伏或SD-Ag冷霜。另对60例糖尿病足部溃疡创面应用同剂量德莫林。观察各创面的愈合情况,检测患者血、尿常规及肝、肾功能等指标有无改变。结果(1)细胞实验:培养12、20d时,实验组细胞的增殖倍数及培养上清液中Ⅳ型胶原、EGF的含量均明显高于对照组(P<0.01).(2)动物实验:浅Ⅱ、深Ⅱ度治疗组创面肉芽组织增生或上皮覆盖的时间均明显早于同深度对照组创面。浅Ⅱ度治疗组创面伤后7、10、14d的愈合率以及深Ⅱ度治疗组创面伤后5、10、18d的愈合率均明显高于同深度对照组创面(P<0.05).(3)临床应用:浅Ⅱ、深Ⅱ度治疗组创面治疗5、10d时的创面愈合率均明显高于同深度对照组创面(P<0.05),其创面愈合时间以及供皮区治疗组创面愈合时间均早于各自的对照组创面(P<0.05).60例糖尿病足患者治疗前足部溃疡面积为(39±28)cm2,治疗2周后缩小为(19±23)cm2,总有效率达62.5%。各患者治疗前后血常规及肝、肾功能等指标无明显改变。结论无机活性元素对上皮细胞的增殖、分化及创面愈合有明显的促进作用。     

Fascial incisions heal faster than skin: a new model of abdominal wall repair

BACKGROUND: Optimal healing of the fascial layer is a necessary component of complete abdominal wall repair. The majority of acute wound healing studies have focused on the dermis. We designed a model of abdominal wall repair that, to our knowledge, for the first time simultaneously characterizes differences in the wound healing trajectories of the fascia and skin. METHODS: Full-thickness dermal flaps were raised on the ventral abdominal walls of rats, and midline fascial celiotomies were completed. The dimensions of the flap were developed so as to have no detrimental effect on skin healing. The dermal flaps were replaced so that the fascial incisions would heal separately from the overlying skin incisions. Animals were killed 7, 14, and 21 days after operation and fascial and dermal wounds were harvested and tested for breaking strength. Fascial and dermal wounds were also compared histologically for inflammatory response, fibroplasia, and collagen staining. RESULTS: Fascial wound breaking strength exceeded dermal wound breaking strength at all time points (9.16 +/- 2.17 vs 3.51 +/- 0.49 N at 7 days, P <.05). Fascial wounds also developed greater fibroblast cellularity and greater collagen staining 7 days after the incision. There was no difference in wound inflammatory response. CONCLUSIONS: Fascial incisions regain breaking strength faster than simultaneous dermal incisions. The mechanism for this appears to involve increased fascial fibroplasia and collagen production after acute injury.     

Triphala promotes healing of infected full-thickness dermal wound

BACKGROUND: Infection is a major problem in the management of wounds. Even though the development of synthetic antimicrobial agents persists, drug resistance and toxicity hinder their way. Many plants with multi-potent pharmaceutical activities may offer better treatment options, and Triphala (dried fruits of Terminalia chebula, Terminalia bellirica, and Phyllanthus emblica) are potential formulations evaluated for healing activity on infected wound as it possesses numerous activities. MATERIALS AND METHODS: Alcoholic extract of Triphala has shown in vitro antimicrobial activity against wound pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes. An ointment was prepared from the Triphala extract (10% w/w) and assessed for in vivo wound healing on infected rat model by rate of healing, bacterial count, biochemical analysis, and expression of matrix metalloproteinases. RESULTS: The treated group has shown significantly improved wound closure. Assessment of granulation tissue on every fourth day showed significant reduction in bacterial count with significant level of collagen, hexosamine, uronic acid, and superoxide dismutase in the treated group (P < 0.01). Reduction of matrix metalloproteinase expression observed in the treated group by gelatin zymography and immunoblotting confirms our in vivo assessment. CONCLUSIONS: The above results showed the antibacterial, wound healing, and antioxidant activities of Triphala ointment, necessary for the management of infected wounds. Active principles of the Triphala may be further evaluated and used as an excellent therapeutic formulation for infected wounds.     

A recombinant signalling-selective activated protein C that lacks anticoagulant activity is efficacious and safe in cutaneous wound preclinical models

Various preclinical and clinical studies have demonstrated the robust wound healing capacity of the natural anticoagulant activated protein C (APC). A bioengineered APC variant designated 3K3A-APC retains APC's cytoprotective cell signalling actions with <10% anticoagulant activity. This study was aimed to provide preclinical evidence that 3K3A-APC is efficacious and safe as a wound healing agent. 3K3A-APC, like wild-type APC, demonstrated positive effects on proliferation of human skin cells (keratinocytes, endothelial cells and fibroblasts). Similarly it also increased matrix metollaproteinase-2 activation in keratinocytes and fibroblasts. Topical 3K3A-APC treatment at 10 or 30 μg both accelerated mouse wound healing when culled on Day 11. And at 10 μg, it was superior to APC and had half the dermal wound gape compared to control. Further testing was conducted in excisional porcine wounds due to their congruence to human skin. Here, 3K3A-APC advanced macroscopic healing in a dose-dependent manner (100, 250 and 500 μg) when culled on Day 21. This was histologically corroborated by greater collagen maturity, suggesting more advanced remodelling. A non-interference arm of this study found no evidence that topical 3K3A-APC caused either any significant systemic side-effects or any significant leakage into the circulation. However the female pigs exhibited transient and mild local reactions after treatments in week three, which did not impact healing. Overall these preclinical studies support the hypothesis that 3K3A-APC merits future human wound studies.     

Non‐surgical treatment of deep wounds triggered by harmful physical and chemical agents: a successful combined use of collagenase and hyaluronic acid

Some chronic ulcers often occur with slough, not progressing through the normal stages of wound healing. Treatment is long and other therapies need to be performed in addition to surgery. Patients not eligible for surgery because of ASA class (American Society of Anesthesiologists class) appear to benefit from chemical therapy with collagenase or hydrocolloids in order to prepare the wound bed, promoting the healing process. We describe four cases of traumatic, upper limb deep wounds caused by different physical and chemical agents, emphasising the effectiveness of treatment based on topical application of collagenase and hyaluronic acid (HA) before standardised surgical procedures. We performed careful disinfection of lesions combined with application of topical cream containing hyaluronic acid, bacterial fermented sodium hyaluronate (0·2%w/w) salt, and bacterial collagenase obtained from non‐pathogenic Vibrio alginolyticus (>2·0 nkat1/g). In one patient a dermo‐epidermal graft was used to cover the wide loss of substance. In two patients application of a HA‐based dermal substitute was done. We obtained successful results in terms of wound healing, with satisfactory aesthetic result and optimal recovery of the affected limb functionality. Topical application of collagenase and HA, alone or before standardised surgical procedures allows faster wound healing.     

Evaluation of a cross-linked versus non-cross-linked collagen matrix in full-thickness skin defects

Autologous skin transplantation is the gold standard for treatment of full-thickness skin defects such as deep burn injuries, but has the disadvantages of limited donor sites and donor site morbidities. Alternative skin replacement products, such as xenografts and allografts, are not a permanent solution. Numerous manufactured skin substitutes already show promising approaches, but have limited efficacy. Therefore, wound dressings adaptable to the physiology of wound healing are still needed.In a randomized controlled in vivo study, a newly designed biocompatible collagen nonwoven matrix was compared to the Integra® bilayer dermal substitute and untreated controls in 48 full-thickness skin defects in a swine model.The take of all templates was complete, and all the tissue-engineered products accelerated dermal wound healing compared to the untreated controls, as identified by planimetric measurements. The higher collagen dose treatments and Integra®-covered wounds developed the thickest, cell-rich neoepidermal tissue in histological examination.The innovative biocompatible collagen matrix is flexibly applicable and modifiable, and offers potential as a carrier membrane for therapeutic supplemental products such as growth factors to further develop effective wound dressings.     

创面用变革对深Ⅱ°烧伤创面愈合时间的影响

目的通过对深Ⅱ°烧伤创面愈合时间的分阶段对比分析,了解创面愈合观念及创面用药变革对创面愈合速度的影响。方法1982年1月～1999年12月对1563例小面积深Ⅱ°烧伤患者(总面积≤10%),按创面补锌及生长因子和胶原酶应用等治疗措施采用时间不同,分为时间阶段,对比观察创面愈合速度变化。结果1982年1月～1990年12月,未使用特殊创面外用药物,创面愈合时间为(23.8±3.5)天;1991年～1996年,采用银锌霜创面补锌,创面愈合时间为(20.6±3.2)天;1997年～1999年,将脱痂药物(胶原酶)及生长因子与银锌霜联合使用,使创面愈合时间缩短为(16.2±2.8)天。结论创面愈合观念及创面用药变革促进了深Ⅱ°创面愈合。