ObjectiveTo review the research progress of modern biological dressings. MethodsThe related literature at home and abroad was reviewed, analyzed, and summarized in the progress of biological dressing situation and various types of biological dressing research. ResultsCompared with the traditional dressing, the biological dressing can greatly promote wound healing. Biological dressings are mainly divided into the natural materials, artificial synthetic materials, and drug loaded dressings. The natural material dressings are mainly the alginate dressing, this kind of dressing can promote wound healing, which has been confirmed by a large number of studies. The artificial synthetic materials include film dressings, liquid, water colloids, gels, and foam, each has its own advantages and disadvantages, which can be chosen according to need. The drug dressing can play the role of drug loading, and further promote the wound healing; using microcapsule technology to construct the dressing and choosing Chinese medicine as drugs is the research direction of load. ConclusionThe experiment and clinical application of biological dressing are many types, clinical application prospect is wide, but each has its own advantages and disadvantages, further study is needed to improve its efficacy.
OBJECTIVE: To explore the molecular mechanisms involved in the increased collagen synthesis by platelet-derived wound healing factors (PDWHF) during wound healing in alloxan-induced diabetic rats. METHODS: Thirty-three male SD rats were divided into two groups, the normal (n = 9) (group A) and the diabetic group (n = 24). Two pieces of full-thickness skin with diameter of 1.8 cm were removed from the dorsal site of diabetic rats. PDWHF (100 micrograms/wound) was topically applied to one side of the diabetic wounds (group B) on the operation day and then once a day in the next successive 6 days. Meanwhile, bovine serum albumin (100 micrograms/wound) was applied to the other side of diabetic wound as control group (group C) in the same way. Levels of transforming growth factor-beta 1 (TGF-beta 1) and procollagen I mRNA in wound tissue were inspected by dot blotting. RESULTS: TGF-beta 1 mRNA levels in group B were 4 folds and 5.6 folds compared with those in group C after 5 and 7 days (P lt; 0.01), however, still significantly lower than those of group A (P lt; 0.05). There was no significance difference among three groups on the 10th day after wounding. The levels for procollagen I mRNA in group B amounted to 2.1, 1.8 and 2.3 folds of those in group C after 5, 7, and 10 days (P lt; 0.01), respectively. Compared with those in the group A, procollagen I mRNA levels in the group B were significantly lower after 5 and 7 days (P lt; 0.05), and no significant difference was observed between group B and A after 10 days. CONCLUSION: One important way for PDWHF to enhance the collagen synthesis in diabetic wound healing is to increase the gene expression of endogenous TGF-beta 1.
OBJECTIVE The effect of platelet-derived wound healing factor (PDWHF) on wound healing in diabetic rats was studied. METHODS Forty-four male SD rats were randomly divided into 2 groups. Thirty-two rats of experimental group accepted intraperitoneal injection of alloxan (1.5 mg/10 g body weight). Within one or two days after injection, while the blood sugar of the rats was higher than 180 mg/dl, the animal model of diabetic rat should have been established. Then a dorsal incision was given to every rat. After the addition of PDWHF (the experimental group) or bovine albumin (the control group), the incision was sutured up. Seven, ten and fourteen days after operation, the breaking strength of the wound was measured. On another hand, specimen from the wound was taken for the culture of fibroblasts. When the cultured fibroblasts have been incubated with 10% PDWHF for 4, 8 and 12 hours, the procollagen I (alpha 1) mRNA levels were examined respectively, and compared with those of control. RESULTS Significant difference in wound breaking strength had been observed between PDWHF-treated incisions and the control on 7, 10 and 14 days after wounding (P lt; 0.01). Experiment in vitro demonstrated that the procollagen I (alpha 1) mRNA levels in wound fibroblasts incubated with 10% PDWHF for 4, 8 and 12 hours were 0.9, 3.7 and 2.2 folds higher than those in fibroblasts in control. CONCLUSION It was suggested that direct stimulation of procollagen I (alpha 1) gene expression was one of the ways that PDWHF played its role in accelerating wound healing.
OBJECTIVE To investigate clinical effects and possible mechanisms of various growth factors on impaired healing ulcers of patients with diabetic disease. METHODS Seventy-eight patients were divided into three groups; saline control, epidermal growth factor(EGF) experimental group, and platelet-derived wound healing factor (PDWHF) experimental group. General healing conditions, wound closing index, healing rates and histological changes of the patient’s ulcer wound were observed during 1-8 weeks after treatment. RESULTS The wound closing index and healing rate of ulcers were significantly increased in the EGF and PDWHF experimental groups compared with the control group, while the angiogenesis, fibroblast hyperplasia, and collagen deposit were more obvious in EGF and PDWHF experimental groups than that of control group. The promoting effects on wound healing in PDWHF experimental group were better than in EGF group. CONCLUSION It suggests that local application of certain growth factor alone or various growth factors together is an effective method to improve the condition of impaired healing of diabetic ulcers.
Hyaluronic acid (HA) is an extracellular matrix having a high molecular weight. This study is to investigate (1) whether the ultrapure HA had effect on the healing of full thickness skin wounds in animals, and (2) the relation between the effect of HA and the size of the molecular weight of HA. The ultrapure HA with different molecular weights and HA with intermediate molecular weight were applied topically to the wounds from removal of full thickness of skin and topical application of normal saline was used as control. At 21st, day after the topical application, the tensile strength was reduced in wounds of groups of HA with high and intermediate molecular weights, but not in the group of low molecular weight. Using laser-Doppler scanning of the dynamic changes of the wound perfusion, in the 3rd day the blood supply to the wound was reduced in HA groups of high and intermediate molecular weights, but at the 7th day, the blood supply of all wounds in the two groups was increased. The study revealed that HA with different molecular weights had different actions on the contraction of wounds, the angiogenesis of the granulation tissues and the healing strength of the wounds. It was indicated that hyaluronan could be used for wound treatment or as a carrier, but its accurate composition must be carefully noted.
This experiment was designed to observe the proliferative effects of platelet derived wound healing factor (PDWHF) of different concentrations on fibroblasts from rat wounds and on epithelial from human wounds. Cultured fibroblasts from rat wound and epithelia from human wound were randomly divided into three groups. (1) In blank control, the cells were treated with basic medium (BM, contains 1640/0.5% FCS); (2) the positive control, the cells were treated with 1640/10% FCS and (3) in the PDWHF group, the cells were treated respectively with BM/1% PDWHF, BM/3% PDWHF, BM/5% PDWHF, BM/7% PDWHF, BM/10% PDWHF, BM/12% PDWHF, respectively. The Cells were collected after 48 hours culturing with BM or PDWHF, and the cell proliferation was measured by MTT method according to the OD values. The result showed that the PDWHF could remarkably enhance the proliferation of fibroblasts and epithelial cells when its concentration was between 1% and 7%, which was obviously higher than that of the blank control (P lt; 0.01). When the concentration of PDWHF reached 10%, its proliferative effect was not remarkable when compared with the blank control, When the concentration of PDWHF reached 12%, it showed inhibitory effect on fibroblasts and manifested no obvious inhibitory effect on epithelial cells. It was concluded that the PDWHF was a combination of a variety of growth factors. In a certain range of concentration, the PDWHF might effectively promote the proliferation of fibroblasts and epithelial cells. Howerve, when its concentration reached to relatively higher level, its effect was not remarkable any more, or even showed inhibitory effect on cell proliferation.
To investigate the effect of Insulin and Danshen on anabolism and catabolism of collagen during the healing of wound, fibroblast which was cultured from human embryonic skin were divided into 3 groups: Insulin group, Danshen group and contral group. Each group was cultured for 2, 4 and 6 days, then the growth curve was established respectively. RESULTS: 1. The growth curve showed-insulin group gt; control group gt; Danshen group. 2. The rate of cell division in 3 groups was 19.6/1000, 2.5/1000, 3.77/1000 respectively. 3. The electron microscopic scanning showed that there was much of fibroid tissue surrounding the fibroblast cell in insulin group, but there was little fibroid tissue in Danshen group. The conclusion showed that insulin can accelerates proliferation of fibroblast and synthesis of collagen, but the effect of denshen was just on the contrary.
It was reported in this article that a preparation of acid/heat-stable peptides (AHSP) from pig serum with a molecular-weight less than 18 ku a without antigenity and toxicity could exert enhancement effect on wound healing. Two pieces of polyvinyl alcohol (PVA) sponge implanted in rat dorsal subcutaneous pouchs of 20 mice were selected as the wound model. The subcutaneous pouch having one piece of sponge was taken as the experimental group and the other as the control. Injection of 50 microliters of such peptide preparation into the test sponge was performed once a day from the time of injury on for 5 consecutive times, while 50 microliters of BSA (5 mg/ml) into the control sponge in the same way. The levels of total DNA, protein and hydroproline in AHSP-treated sponge were observed significantly higher than those in the control sponge on the 7th and 10th days after wounding (P lt; 0.05). No significant difference was seen on the 14th postinjury day (P gt; 0.05). The effect of AHSP on proliferation of wound fibroblast cultured in vitro was also detected. In conclusion, such peptides derived from pig serum had the activity to accelerate wound healing without resultant excessive healing and its direct stimulation of the proliferation of wound fibroblast was probably one of the way which AHSP exerted its action.
Abstract To observe the effect of exogenous high molecular weight nerve growth factor (HMW-NGF) mixed with bletilia striata gelatin (BSG) in the promotion of healing, the experiment was performed as follow: (1) In serumfree medium, the normal saline, BSG, HMWNGF, and BSG+HMW-NGF were added separately, and then, the chick embryo root ganglions (DRGs) were cultivated in the above prepared media and the axonal growth was observed. (2) 40 SD rats were divided into 4 groups. A wound of 2cm×2cm was made on the back of every rat. No treatment was given in group one. In other groups, BSG, HMW-NGF, andBSG+HMW-NGF were given separately to the wounds once daily. After 3 and 10 days, the wound area of every rat was measured, cells in the wounds were observed under light microscope and were calculated, and the time of healing was recorded. The results showed that BSG, HMW-NGF, especially BSG+HMW-NGF could promote wound healing.