OBJECTIVE: To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing. METHODS: Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3. RESULTS: The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group. CONCLUSION: NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.
Objective To investigate the influence of lipopolysaccharide(LPS) on the proliferation and collagen synthesis of normal human skin fibroblasts so as to elucidate its relation with skin wound healing. Methods Fibroblasts wereisolated and cultured in vitro, and then exposed to different doses of LPS(0.005, 0.010, 0.050, 0.100, 0.500, and 1.000 μg/ml) from E.coli055∶B5 respectively. Then the absorbance (A) value of fibroblasts was determined with the colorirneteric thiazolylblue (MTT) assay, and the cell number was counted under inverted phase contrast microscope from the 1st day to the 9th day after LPS administration, and collagen synthesis of fibroblasts in culture medium was measured with the method of pepsin digestion after incorporation of 3Hproline into stable, single-layered, confluent fibroblasts at 7 days after LPS administration. Results Compared with control group, A value increased with the increasing concentration of LPS (0.005 μg/ml 0.500 μg/ml) and LPS of 0.100 μg/mlgroup had the best effect. The difference was remarkable from the 5th day to the 9th day(P＜0.05). A value decreased when challenged with the LPS of 1.000 μg/ml and the difference was remarkable from the 3rd day to the 9th day(P＜0.05). Cell number increased with theadministration of LPS of different concentrations (0.005 μg/ml 0.500 μg/ml) and LPS of 0.100 μg/mlgroup had the best effect. The difference was remarkable from the 1st day to the 6th day(P＜0.05). Cell number decreased remarkably when challenged with LPS of 1.000 μg/ml and the difference was remarkable from the 2nd day to the 9th day(P＜0.05). Collagen synthesis increased when challenged with LPS of different concentrations (0.005 μg/ml 0.500 μg/ml) and the 0.100 μg/ml group had the best effect. However, when the dose of LPS reached 1.000 μg/ml, it inhibited collagensynthesis. Conclusion LPS could promote the proliferation andcollagen synthesis of fibroblasts within a certain range of low doses, but over-high dose ofLPS might inhibit the proliferation and collagen synthesis of fibroblasts, suggesting that LPS of certain concentrations might contribute to wound healing, while excessive LPS has negative effect on wound healing.
OBJECTIVE: To investigate the efficiency of recombinant human epidermal growth factor (rhEGF) on burn wound healing and to explore the effective density of the ointments. METHODS: A total of 120 cases of burn in superficial II degree and profound II degree were randomly divided into 2 groups. In the first group of 15 cases of superficial II degree, the wounds were treated by rhEGF ointments of different density, 0.5 microgram/g, 10 micrograms/g and 50 micrograms/g, to screen out the effective density. And in the other 105 cases of the second group, optimal density of the ointments based on the result of the first group were employed to treat the burn wound in superficial II degree and profound II degree, with the self-corresponding wounds of the same degree as control, to study the efficiency of rhEGF on wound healing, according to the wound healing time, and adverse reaction of the ointment. RESULTS: In the first group, the average healing time of superficial II wound treated by ointments of 10 micrograms/g and 50 micrograms/g significantly shortened when compared with that treated by ointments of 0.5 microgram/g(P lt; 0.01), but there was no obvious difference between the cases treated by ointments of 10 micrograms/g and 50 micrograms/g. In the second group, the healing time of superficial II wound treated by ointments of 10 micrograms/g was (8.39 +/- 2.25) days, (9.52 +/- 2.56) days in the control (P lt; 0.01); and healing time of profound II burn treated by ointments of 10 micrograms/g was (16.80 +/- 2.99) days, (18.27 +/- 3.17) days in the control (P lt; 0.01). And healing rates of burn wound at different periods were higher than those of the control. CONCLUSION: The above results indicate that rhEGF ointments can enhance burn wound healing significantly, and the ointment of 10 micrograms/g is a good choice for clinical application.
OBJECTIVE: To study the therapeutic effect of Suyuping in which liposome is the main constituent on II degree burn wound. METHODS: From October 1998 to October 1999, 42 cases with II degree burn wound were adopted in this study. Among them, there were 30 males and 12 females, the average wound area was (23.4 +/- 9.7)%. The wounds on the left side of body were managed with sulfadiazine argentum(SD-Ag) while that on the right side with Suyuping. Healing and other situation about the burn wounds were observed and recorded at times. RESULTS: Forty-two patients completely healed when discharged from hospital. The average wound area managed with Suyuping was (11.2 +/- 7.3)% and the area with SD-Ag was (9.4 +/- 5.8)%. The mean healing time of Suyuping group was(18.4 +/- 4.7) days while that of SD-Ag was (23.5 +/- 7.9) days, there was significant difference(P lt; 0.05). Suyuping group presented few wound pain, allergy, bleeding and the side effect was less. CONCLUSION: Suyuping can accelerate wound healing and attenuate wound pain, allergy and bleeding, it is a potential and specific topical agent for treating II degree burn wound.
【Abstract】 Objective To search for a feasibil ity of repairing full-thickness cutaneous deficiency with tissueengineered skin substitute composited by human epidermal stem cells and fibroblasts in fibrin frame. Methods Epidermal stem cells and fibroblasts were harvested from human epidermis and dermis by trypsin digestion. Cells were cultured and subcultured in non-serum medium. Epidermal stem cells (5×104/mL) and dermal fibroblasts (1×104/mL) in 0.5 mL medium were coagulated in 0.5 mL fibrin frame to construct tissue engineered skin substitute. The tissue engineered skin substitute was grafted onto full-thickness cutaneous deficiency of nude mice. Forty-five male mice, 4-5 week old, weighted 20 g on average, were randomly divided into 5 groups. Oil yarn (group C), fibrin frame membrane without cell inoculation (group F), composite skin substitute with epidermal stem cells (group S) and composite skin substitute with fibroblasts (group Fb) were used as controls, while tissue engineered skin substitute (group T) was experimental group. The wounds were observed 1, 3, 6, 8 weeks after surgery. Samples were harvested 3, 6, 8 weeks after surgery, and were examined by means of histology、immunohistochemistryand scanning electron microscopy (SEM). Results Four weeks after cell culture, there were some round cells in the culture capsule of epidemic cells, and some fusiform cells in the culture capsule of fibroblast. Six days after cells were cultured in the BrdU culture medium, there were some BrdU positive cells appeared. There were some CK19 positive cells and Nestin positive cells appeared in the chaff of group T before transplanting. The new formed skin of group T grew faster and had less scar than other groups. Six weeks after surgery, the average thickness of new formed skin was (0.460 ± 0.049) mm in group C, (0.480 ± 0.055) mm in group F, (0.540 ± 0.043) mm in group S, (0.510 ± 0.032) mm in group Fb, (0.660 ± 0.047) mm in group T. The thickness of new formed skin in group T was thicker than other groups (P lt; 0.05). By histology and SEM observation, 3, 6, 8weeks after surgery, the new formed cuticular layer, fibroblast and blood vessels in the group T were more than those in theother groups. The al ignment of blood vessels and collagen fibers in group T were much regular than those in the other groups. Three weeks after surgery, the new formed skin of group T had a continuous color zone of positive collagen Ⅳ staining, while no continuous color zone was found in the other groups. Six weeks after surgery, CK14 positive cells appeared in the new formed skin of group T, while no positive cell was found in the other groups. Conclusion Tissue engineered skin substitute which is composited with epidermal stem cells and fibroblasts in fibrin frame has potential prospects in appl ication of repairing fullthickness cutaneous deficiency with advantage of faster wound heal ing.
Abstract In order to understand the expression change of epidermal growth factor (EGF) gene and its distribution in tissue duringwound healing, 12 Winstar rats were divided into 4 groups. In each side of the back of every rat, 4 wounds of 1.5cm×1.5cm in size were made. After 4,8,12,16 days, one group of rats was sacrificed and tissues from wound were collected. By DIG-labelled probe hybridization in situ technique, EGF gene mRNA was detected. It was shown that EGF gene expression was evident during the whole stage of woundhealing, and the peak was in 8th day. It suggested that the promotion of EGF gene expression may lead to wound healing earlier.
OBJECTIVE: To investigate the availability and effect of skin stretch in closing the firearm injured soft tissue defect. METHODS: Eight white pigs with firearm injured soft tissue defect were divided into 3 groups. Each group I and group II had 3 pigs which were performed skin stretch. The control group had 2 pigs without stretch. The average diameter of the defect in three groups was (7.3 +/- 0.2) cm, (9.1 +/- 0.3) cm, (7.3 +/- 0.2) cm respectively, and the site of defect was on the lateral thigh and buttock. RESULTS: Skin stretch could make a visible reduction of the wound. It was possible to close the wound by direct traction when the diameter of the buttock wound was less than 7 cm, and when the diameter of the lateral thigh wound was less than the radius of thigh. The skin stretch should not last more than 7 days and the best effect appeared in 4 to 5 days after performing the skin stretch. CONCLUSION: The skin stretch can be applied in the repair of the firearm injured soft tissue defect. It has many advantage compared with the tradtional treatment.
OBJECTIVE: With the recognization of the mechanism of wound healing, some topical agents are created and applied in trauma to improve the healing rate of wounds. The main purpose of this study is to investigate the effect of some topical agents on the healing rate of deep second-degree burn wounds. METHODS: One thousand five hundred and sixty-three patients with deep second-degree burn wounds(total burn surface area lt; or = 10%) were involved in this study from January 1982 to December 1999. According to the application time of different treating measures including supplement of Zn, application of growth factors and collagenase, the patients were divided into 3 groups, wound healing rates were compared. RESULTS: Before 1991, none of special topical agents were used, and the healing time of deep second-degree burn wounds was(23.8 +/- 3.5) days. From 1991 to 1996, with the topical application of SD-Ag-Zn, which can provide Zn for cells taking part in wound healing, the healing time of deep second-degree burn wounds was (20.6 +/- 3.2) days, earlier than no special topical agents (P lt; 0.05). From 1997 to 1999, growth factors such as basic fibroblast growth factor(bFGF) and epithelial growth factor (EGF) and collagenases were applied in wound treatment combining with SD-Ag-Zn, wound healing time was (16.2 +/- 2.8) days, earlier than no special topical agents (P lt; 0.01) and simple SD-Ag-Zn application (P lt; 0.05). CONCLUSION: It indicates that the improvement of topical agents can accelerate wound healing speed.
Objective To observe the effects of sal iva on impaired raw surface so as to elucidate the possible mechanism in wound heal ing by comparing with Yunnan baiyao. Methods Six wounds (2.5 cm × 2.5 cm in size) were establ ished at both sides on the back of 6 3-month-old adult Japanese rabbits (weighing 2.0-2.5 kg). According to treatment, 36 wounds were randomly divided into 3 groups: wounds were treated with 0.4 mL normal sal ine (blank control group, n=12), 0.5 g Yunnan baiyao powder (Yunnan baiyao group, n=12), and 0.4 mL sal iva of health adult (sal iva group, n=12) for 15 days, respectively. And the general observation of raw surface, the scar formation time, wound healing rate, and histopathology were used to evaluate the effectiveness of sal iva on wound heal ing. Results The wound healing speeds of sal iva group and Yunnan baiyao group were faster than that of blank control group. The wound healing rates of sal iva group were significantly higher than those of blank control group and Yunnan baiyao group at 5, 8, and 11 days after injury (P lt; 0.05). No obvious hemorrhage or necrosis of raw surfaces was observed in sal iva group, and the raw surfaces generally were covered with epidermis at 15 days after injury. The inflammatory cells and microvessel density in sal iva group were significantly less than those of Yunnan baiyao group and control group (P lt; 0.05). Conclusion Sal iva could obviously improve wound heal ing, which is related to its effects on reducing inflammatory cell infiltration, preventing wound infection, accelerating collagen fibers prol iferation, and promoting vessel reconstruction in the process of wound heal ing.
Objective To explore the efficacy and safety of bioactive material(combest) which is combinated with bioglass and hyaluronan on burn wound healing．Methods From March to September 2006, 20 patients were treated; including 16 males and 4 females, aging 18-58 years(40 years on average)．The wounds were classified as deep degrees Ⅱ in 7 cases, granulated wounds in 9 cases and graft site wounds in 4 cases. Twenty wounds in one side were repaired with Combest as the test group and 20 wounds in the other side with blank cream as the control group. The wounds in size ranged from 2.0 cm×1.5 cm to 40.0 cm×20.0 cm. The wound healing rate was observed, and the blood test and the indices of hepatic and renal function were determined on the 1st, 3 rd,6 th, 11 th, 16 th and 21 st days of treatment．Results Wound healed within 3 weeks in 11 cases of the test group (3 cases on the 11 st day, 4 on the 16 th day, and 4 on the 21 st day) , but no wound healing was observed within 3 weeks in the control group. The healing size accounted for 2/3 of wounds in 18 cases of the test group and in 1 case of the control group. The excellent and good rates were 95%(18 cases and 1 case) in the test group and 50% (1 case and 9 cases) in the control group, showing significant difference (Plt;0.01). For all patients, no obvious changes were found in the blood test and hepatic or renal function indices. Conclusion Combest combinated with bioglass and hyaluronan is beneficial to the proliferation of the granulation and wound healing with good safety.