Effects of different artificial dermal scaffolds on vascularization and scar formation of wounds in pigs with full-thickness burn / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of three kinds of artificial dermal scaffolds on vascularization and scar formation of wounds in pigs with full-thickness burn.</p><p><b>METHODS</b>Eighteen 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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSIONS</b>The 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.</p>

Comparison of the mechanisms of intralesional steroid, interferon or verapamil injection in the treatment of proliferative scars / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of intralesional steroid, interferon alpha-2b or verapamil injection on proliferation, apoptosis and TGF-beta1 expression in keloid and hypertrophic scar in vivo.</p><p><b>METHODS</b>6 patients with keloids and 6 patients with hypertrophic scar were treated with intralesional injection of triamcinolone acetonide (40 mg/ml) or IFN alpha-2b (15 x 10(5) U/ml) or verapamil (2.5 mg/ml). Samples were collected on the 7th day after intralesional injection. Samples of untreated keloid and hypertrophic scar and normal skin were used as control. Expression of PCNA and TGF-beta1 was detected in situ by immunohistochemical staining, and apoptosis was detected in situ by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL).</p><p><b>RESULTS</b>1) Triamcinolone acetonide could prohibit proliferative scars through inhibiting cell proliferation and TGF-beta1 expression, as well as inducing apoptosis. 2) IFN alpha-2b could prohibit proliferative scars through inhibiting cell proliferation and TGF-beta1 expression, but not inducing apoptosis; 3) Verapamil could also prohibit proliferative scars through inhibiting proliferation and TGF-beta1 expression in fibroblasts, as well as inducing apoptosis. While the effect of inducing apoptosis was stronger than that of triamcinolone acetonide, the effect of inhibiting TGF-beta1 expression was weaker than those of triamcinolone acetonide and IFN alpha-2b.</p><p><b>CONCLUSIONS</b>Although intraleional injection of steroid, interferon alpha-2b or verapamil were all effective in the treatment of keloid and hypertrophic scar, their mechanisms are not similar.</p>

Early transplantation of double rectus abdominis musculo-cutaneous flaps from upper abdomen for the repair of patients with electrical injury in the wrist / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effect of the early transplantation of double rectus abdominis musculo-cutaneous flaps on the repair of electrical injury of the wrist.</p><p><b>METHODS</b>The study involved six patients suffering from circumferential deep electrical burn with only small amount of normal skin left on the dorsal side. The wounds were covered with double rectus abdominis musculo-cutaneous flaps raised from the upper abdomen with pedicles in both proximal and distal ends at an early postburn stage. The postoperative recovery of wrist function and wound repair were evaluated.</p><p><b>RESULTS</b>The wrist wounds in all the 6 patients were primarily healed, with perfect function and appearance.</p><p><b>CONCLUSION</b>Early application of double rectus abdominis musculocutaneous flaps on the electrically injured wrists can promote the wound healing processes and plays important roles in the preservation of wrist function.</p>