Antimicrobial activities of hydrogel burn wound dressing and chitosan were investigated against nine strains of bacteria and fungi, including P. aeruginosa, S. aureus, Enterobacter, P. vulgaris, P. mirabilis, E. coli, Klebsiella, B. subtilis, C. albicans. The results showed that both hydrogel dressing and chitosan have antimicrobial effect and the effect of hydrogel dressing is higher than that of chitosan. Antimicrobial activity of hydrogel dressing in experiment in rabbit was also tested.
burns ; chitosan

The chitosan produced from carapace of shrimp was used under cream form with concentration of 2% to treat experiment thermal burn wounds on 30 rabbits. Two thermal burn wounds were created on each rabbit, one of them was treated by excipient only or silver sulfadiazin cream 1% or maduxin ointment. The experimental results showed that:- Chitosan had antibacterial effect, especially on S.aureus, P.aeruginosa and E.coli. These dangerous bacteria resisted against many antibiotics. -The antibacterial effect of chitosan was similar to that of silver sulfadiazin and maduxin.
Chitosan, burns

A study on the histological changes in the experimental burn treated by chitosan cream, comparing with sulfadiazine-silver 1%, and maduxin ointment has shown that chitosan increased the process of tissue regeneration and wound healing. These activities were equivalent to these of sulfadiazine-silver cream 1% and maduxin ointment.
burns, chitosan

The bactericidal efficacy of chitosan cream on burn wounds of 82 burn patients with degree II, III, area 4-50%, in National Burn Institute was evaluated. The results of the study showed that: chitosan had a good bactericidal efficacy to bacteria infected burn wounds, led by S.aureus, followed by enterobacterial. Chitosan cream had very high efficacy at burn wounds, the amount of bacteria decreased clearly 14 days after treatment. The bactericidal efficacy of chitosan cream was similar to silver sulfadiazine cream 1%.
Burns ; Wounds and Injuries ; Chitosan ; Bacteria

OBJECTIVETo investigate the roles and differences of angiogenesis of different dermal scaffolds on wound contraction and apoptosis during full-thickness burn wound repair.

METHODSWounds were observed at different time after the collagen-sulfonated carboxymethyl chitosan porous scaffold or collagen-chitosan porous scaffold or acellular dermal matrix were respectively transplanted on wounds of full thickness burn with debridement in Bama miniature pigs. At the same time, vessels and myo-fibroblasts expressing α-smooth muscle action(α-SMA) and apoptosis in wounds of different time were detected in situ by immunohistochemical staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling. The burn wounds without any scaffold transplantation were studied as the control.

RESULTSWounds with different scaffolds transplantation were different from granulation wounds. Vessels expressing α-SMA had been increasing continuously in the wounds from 1 to 3 weeks after different scaffolds transplantation and decreased in wounds after epidermis had been grafted for 2 weeks on surface of the scaffolds transplanted on wounds for 2 weeks. Vessels expressing α-SMA were the most in the wounds with collagen-sulfonated carboxymethyl chitosan porous scaffold transplantation and the least in the control wounds without dermal scaffold at different time. Myo-fibroblasts expressing α-SMA was the least in the wounds with collagen-sulfonated carboxymethyl chitosan porous scaffold transplantation and the peak of expressions was on the 2nd week, however, the peak in the wounds with the other two scaffolds transplantation and in the control wound without dermal scaffold was on the 3rd week. Myo-fibroblasts expressing α-SMA was the most in the control wounds. Apoptosis had been increasing continuously in the transplantation wounds from 2 to 4 weeks after different scaffolds transplantation, however, apoptosis had begun to increase continuously from 3 to 4 weeks in the control wounds. Apoptosis was the most in the wounds with collagen-sulfonated carboxymethyl chitosan porous scaffold transplantation and the least in the control wounds without dermal scaffold from 3 to 4 weeks.

CONCLUSIONSulfonated carboxymethyl chitosan can promote migration of reparative cells and angiogenesis, and it can repair full-thickness burn wound fast and well.

Animals ; Apoptosis ; Burns ; pathology ; surgery ; Chitosan ; analogs & derivatives ; pharmacology ; Collagen ; Disease Models, Animal ; Female ; Skin Transplantation ; Skin, Artificial ; Swine ; Tissue Scaffolds

OBJECTIVETo compare differences of angiogenesis among collagen- chitosan, collagen-sulfonated carboxymethyl chitosan porous scaffolds and acellular dermal matrix after these three different scaffolds with silicone membrane were transplanted on the wounds of full thickness burn, and the wound repair of different scaffolds with epidermis grafting on.

METHODSAngiogenesis in different dermal scaffolds, the wound surface and epidermis survival were observed in 1, 2, and 3 weeks after the three different scaffolds were respectively transplanted on wounds of full thickness burn with debridement in 6 Bama miniature pigs (total 18 pigs in 3 groups). At the same time, CD34 positive signals (neo-forming microvessels) were detected by immunohistochemical staining. The wounds without any scaffold transplantation were studied as the control.

RESULTSAngiogenesis had been fundamentally finished in 2 weeks after implantation of collagen- sulfonated carboxymethyl chitosan porous scaffold. And fundamental angiogenesis in collagen- chitosan porous scaffolds and acellular dermal matrix needed at least 3 weeks. Neo-forming micro-vessels perpendicular to wound beds with these three different scaffolds were more than those in the control wounds without scaffold. CD34 positive signals (neo-forming micro-vessels) were significantly higher in wounds at the second week than those in wounds at the first week. And those in wounds at the third week were significantly higher than those in wounds at the second week in all wounds with different scaffold transplantations and the control wounds. CD34 positive signals in the group of sulfonated carboxymethyl chitosan porous scaffold on the 1st, 2nd and 3rd week after the scaffold transplantation were significantly higher than those corresponding signals in the other three groups. Epidermis on the sulfonated carboxymethyl chitosan porous scaffold which had been transplanted on burn wound for 1 week could survive perfectly, however, epidermis on the collagen- chitosan porous scaffold or acellular dermal matrix could not survive until these two scaffolds had been transplanted on the burn wounds for at least 2 weeks.

CONCLUSIONSThese three different scaffolds could repair the full thickness skin defects caused by burn, and angiogenesis of sulfonated carboxymethyl chitosan porous scaffold is the best.

Animals ; Burns ; surgery ; Chitosan ; analogs & derivatives ; Collagen ; Disease Models, Animal ; Female ; Silicones ; Skin Transplantation ; Skin, Artificial ; Swine ; Swine, Miniature ; Tissue Scaffolds

OBJECTIVETo investigate the effects of three kinds of artificial dermal scaffolds on vascularization and scar formation of wounds in pigs with full-thickness burn.

METHODSEighteen Bama miniature pigs were divided into chitosan scaffold (CS) group, sulfonated carboxymethyl chitosan scaffold (SCCS) group, and acellular dermal matrix (ADM) scaffold group according to the random number table, with 6 pigs in each group. Every pig in all groups was inflicted with 4 or 8 full-thickness scald wounds on the back (totally 96 wounds). Forty-eight hours after injury, eschars of all wounds were excised. Twenty-four wounds in CS group were transplanted with double-layer artificial dermis of collagen-chitosan and silicone rubber, those in SCCS group with double-layer artificial dermis of collagen-sulfonated carboxymethyl chitosan and silicone rubber, and those in ADM scaffold group with ADM. The rest 24 wounds in the three groups were dressed with vaseline gauze as control group. After 2 weeks of treatment, all wounds of every group were covered with skin. In post treatment (scaffold transplantation or gauze covering) week (PTW) 1, 2, 3, and 4, gross condition of wound was observed, and specimens from central parts of wounds were harvested for observation and assessment of vessels or cells with positive expression of CD31, α smooth muscle actin (α-SMA), TGF-β(1) and TGF-β(3) with SP staining. Data were processed with one-way analysis of variance and LSD test.

RESULTS(1) Degree of vascularization in SCCS group was better than that in the other three groups. (2) The number of vessels with positive expression of CD31 in CS, SCCS, ADM scaffold, and control groups increased gradually from PTW 1 to PTW 3, and decreased in PTW 4. There were statistical differences among 4 groups from PTW 1 to PTW 4 (with F value respectively 24.005, 38.822, 25.274, 3.856, P < 0.05 or P < 0.01). The numbers of vessels that expressed CD31 in SCCS group from PTW 1 to PTW 3 were more than those in the other three groups (with P values all below 0.05). (3) The numbers of vessels that expressed α-SMA in CS, SCCS, and ADM scaffold groups from PTW 1 to PTW 3 showed the similar trend of change to those of vessels that expressed CD31, which increased gradually in control group from PTW 1 to PTW 4. There were obvious differences among 4 groups from PTW 1 to PTW 4 (with F value respectively 22.637, 28.087, 62.651, 18.055, P values all below 0.01). The number of vessels that expressed α-SMA in SCCS group from PTW 1 to PTW 4 was more than that in the other three groups (with P values all below 0.05). (4) From PTW 1 to PTW 4, the number of cells with expression of TGF-β(1) in CS group was respectively (127 ± 8), (167 ± 19), (170 ± 18), (144 ± 10) per 400 times visual field, that in SCCS group was respectively (171 ± 17), (207 ± 25), (130 ± 30), (69 ± 16) per 400 times visual field, that in ADM scaffold group was respectively (106 ± 8), (159 ± 17), (171 ± 11), (145 ± 11) per 400 times visual field, and that in control group was respectively (100 ± 20), (150 ± 18), (200 ± 14), (172 ± 20) per 400 times visual field. There were statistical differences among 4 groups from PTW 1 to PTW 4 (with F value respectively 29.675, 9.503, 13.107, 54.515, P values all below 0.01). Compared with those in SCCS group, the number of cells that expressed TGF-β(1) in the other three groups was decreased in PTW 1, 2 but increased in PTW 3, 4 (with P values all below 0.05). (5) The number of cells that expressed TGF-β(3) in 4 groups increased gradually from PTW 1 to PTW 3, and decreased or increased continually in PTW 4. There were statistical differences among 4 groups from PTW 1 to PTW 4 (with F value respectively 140.612, 945.850, 714.037, 119.147, P values all below 0.01). The number of cells with positive expression of TGF-β(3) in SCCS group from PTW 1 to PTW 4 was more than that in the other three groups (with P values all below 0.05).

CONCLUSIONSThe collagen-sulfonated carboxymethyl chitosan dermal scaffold can rapidly induce growth and maturation of blood vessels during wound healing after burn. It is beneficial for wound repair at early stage with inhibition of scar proliferation.

Acellular Dermis ; Animals ; Burns ; surgery ; Chitosan ; analogs & derivatives ; Cicatrix ; pathology ; Collagen ; Dermis ; transplantation ; Female ; Neovascularization, Physiologic ; Skin Transplantation ; Skin, Artificial ; Swine ; Tissue Scaffolds ; Wound Healing

Various proportions of chitosan/collagen films (70/30% to 95/05%) w/w were prepared and evaluated for its suitability as skin regenerating scaffold. Interactions between chitosan and collagen were studied using Fourier Transform Infrared spectroscopy (FTIR) and Differential Scanning Colorimetry (DSC). Scanning Electron Microscope (SEM) was used to investigate the morphology of the blend. Mechanical properties were evaluated using a Universal Testing Machine (UTM). The chitosan/collagen films were found to swell proportionally with time until it reaches equilibrium. FTIR spectroscopy indicated no chemical interaction between the components of the blends. DSC data indicated only one peak proving that these two materials are compatible at all proportions investigated. SEM micrographs also indicated good homogeneity between these two materials.
Biocompatible Materials/*analysis ; Burns/physiopathology ; Burns/*therapy ; Chitosan/*analysis ; Collagen Type I/*analysis ; *Materials Testing ; Microscopy, Electron, Scanning ; *Occlusive Dressings ; Regeneration/*physiology ; Skin/*physiopathology ; Spectroscopy, Fourier Transform Infrared ; Tensile Strength

OBJECTIVETo investigate the practicability of repair of full skin loss of rabbits with composite chitosan artificial skin.

METHODSDermal substitute was prepared aseptically by mixing fibroblasts with composite dermal matrix gel. Keratinocytes were then seeded on the substitute and submersion - cultured thereafter for 1 week in keratinocyte culture medium. The composite was further cultured for 1 approximately 2 weeks on the surface of the culture liquid to form artificial skin. The composite chitosan artificial skin was then grafted onto the full skin loss wound of rabbits. Histological changes were undertaken periodically by tissue sampling from the grafted wound. The systemic reaction of rabbits to the artificial skin was observed.

RESULTSAll the grafted wounds healed very well without any suppuration, bleeding or infection under the grafted skin. No obvious immune rejection was seen. The artificial skin could cover the wounds for a long time with good elasticity and easy to be manipulation.

CONCLUSIONThe composite chitosan artificial skin could be an optimal biological dressing with good histocompatibility and easy to be manipulation.

Animals ; Burns ; surgery ; Cells, Cultured ; Chitin ; analogs & derivatives ; metabolism ; Chitosan ; Dermatologic Surgical Procedures ; Humans ; Keratinocytes ; cytology ; metabolism ; Male ; Rabbits ; Skin ; injuries ; Skin Transplantation ; methods ; Skin, Artificial ; Transplantation, Heterologous ; Wound Healing

OBJECTIVE: This study tests the efficacy of Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMC), baicalin (BA) and silver titanate (ST) in a wound dressings to fight infection, promote healing and provide superior biocompatibility. METHODS: The antibacterial activity of BA and ST was evaluated in vitro using the inhibition zone method. BA/ST/BSP/CMC porous sponge dressings were prepared and characterized. The biocompatibility of BA/ST/BSP/CMC was assessed using the cell counting kit-8 assay. The therapeutic effect of BA/ST/BSP/CMC was further investigated using the dorsal skin burn model in Sprague-Dawley rats. RESULTS: The wound dressing had good antibacterial activity against Escherichia coli and Staphylococcus aureus through BA and ST, while the combination of BSP and CMC played an important role in promoting wound healing. The BA/ST/BSP/CMC porous sponge dressings were prepared using a freeze-drying method with the concentrations of BA and ST at 20 and 0.83 mg/mL, respectively, and the optimal ratio of 5% BSP to 4% CMC was 1:3. The average porosity, water absorption and air permeability of BA/ST/BSP/CMC porous sponge dressings were measured to be 90.43%, 746.1% and 66.60%, respectively. After treatment for 3 and 7 days, the healing rates of the BA/ST/BSP/CMC group and BA/BSP/CMC group were significantly higher than those of the normal saline (NS) group and silver sulfadiazine (SSD) group (P < 0.05). Interleukin-1β expression in the BA/ST/BSP/CMC group at 1 and 3 days was significantly lower than that in the other three groups (P < 0.05). After being treated for 3 days, vascular endothelial growth factor expression in the BA/BSP/CMC group and BA/ST/BSP/CMC group was significantly higher than that in the NS group and SSD group (P < 0.05). Inspection of histological sections showed that the BA/ST/BSP/CMC group and BA/BSP/CMC group began to develop scabbing and peeling of damaged skin after 3 days of treatment, indicating accelerated healing relative to the NS group and SSD group. CONCLUSION The optimized concentration of BA/ST/BSP/CMC dressing was as follows: 6 mg BSP, 14.4 mg CMC, 0.5 mg ST and 12 mg BA. The BA/ST/BSP/CMC dressing, containing antibacterial constituents, was non-cytotoxic and effective in accelerating the healing of burn wounds, making it a promising candidate for wound healing. Please cite this article as: Gong YR, Zhang C, Xiang X, Wang ZB, Wang YQ, Su YH, Zhang HQ. Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing. J Integr Med. 2023; 21(5): 487-495.
Rats ; Animals ; Chitosan/pharmacology* ; Silver/pharmacology* ; Porosity ; Vascular Endothelial Growth Factor A/pharmacology* ; Rats, Sprague-Dawley ; Wound Healing ; Polysaccharides/pharmacology* ; Bandages ; Burns/drug therapy* ; Anti-Bacterial Agents/pharmacology* ; Silver Sulfadiazine/pharmacology*