摘要
目的探讨烧伤变性脱细胞真皮基质（DADM）作为真皮替代物用于创面修复的可行性。方法（1）取12只Wistar大鼠，其中9只背部造成深Ⅱ度烫伤（以下称烧伤）创面，分别于伤后1、2、3d（每时相点3只）取创面全厚皮肤，用2．5g／L胰蛋白酶-体积分数0．5％Triton X-100行脱细胞处理制成DADM，相应称为DADM-1d、DADM-2d、DADM-3d；余下3只大鼠不致伤，同法制备ADM作为对照。对ADM和各DADM行大体、组织学观察及微生物学和生物力学检测（极限抗拉强度、最大拉力、断裂伸长率、应力-应变关系）。（2）另取64只Wistar大鼠，按随机数字表法分为ADM组、DADM．1d组、DADM-2d组、DADM-3d组，每组16只。于各大鼠背部制作-2．0cm×1．8cm大小皮瓣，将前述ADM和DADM-1d、DADM-2d、DADM-3d切制成1．8cm×1．5cm大小后分别埋植于皮瓣下。术后1、3、5、9周，每组每时相点取4只大鼠，肉眼观察创面愈合情况及埋植物的变化，并对埋植物行组织学观察。对数据行单因素方差分析及t检验。结果（1）新鲜制备的各DADM呈乳白色，质地柔软有弹性，韧性较ADM弱。光学显微镜下见ADM和各DADM中均无上皮结构和细胞存在，DADM胶原纤维增粗程度不均匀，排列紊乱，嗜伊红性增强。各DADM微生物学检测结果均为阴性。DADM-1d、DADM-2d、DADM-3d之间极限抗拉强度、最大拉力、断裂伸长率和应力-应变关系比较，差异均无统计学意义（F值为0．088-3．591，P值均大于0．05）；其中DADM-3d此4项指标值最高，分别为（13．0±2．4）MPa、（61±4）N、（173±7）％、（45．7±2．0）％。ADM此4项指标各为（19．0±2．6）MPa、（95±4）N、（201±5）％、（62．5±2．2）％，与3种DADM两两比较均偏高（t值为6．42±17．125。P值均小于0．01）。（2）埋植术后1周，各组大鼠创面元渗出或红肿，埋植物未收缩或卷曲；创面有炎性细胞浸润并有Fb及毛细血管长人。术后3周时，DADM-1d、DADM-2d、ADM组埋植区毛发生长正常，DADM-3d组埋植区毛发较稀疏；各组炎性细胞减少，Fb增多，有新生小血管长人，DADM．3d组炎性细胞减退稍延迟。术后第5周，各组埋植区毛发恢复正常，埋植物收缩、变薄，表面纤维膜包裹紧密，有较大血管束长人；各组真皮基质与周围正常组织融合。术后第9周，ADM和DADM均为薄、软白色组织片，与皮瓣内面连接紧密；各组无炎性细胞浸润，胶原纤维排列规则、致密，与正常胶原组织融合。结论烧伤DADM无明显免疫原性，生物相容性好，经离体改造有望成为创面修复治疗中的真皮替代物。
Objective To explore the feasibility of burn denatured acellular dermal matrix （DADM） as dermal substitute in repairing wounds. Methods （ 1 ） Nine Wistar rats received a deep par- tial-thickness scald on the back. Full-thickness wounded skin was collected on post scald day （PBD） 1, 2, and 3 （with 3 rats at each time point） , and it was treated with 2.5 g/L trypsin/0. 5% Triton X-100 to re- move cells to prepare DADM, respectively called DADM-1 d, DADM-2 d, and DADM-3 d. Another 3 rats without scald injury were treated with the same method as above to prepare acellular dermal matrix （ADM）to serve as control. Gross and histological observations and microbiological and biomechanical tests, inclu- ding ultimate tensile strength, maximum tension, stretched length at breaking, stress-strain relationship, were conducted for the resulting ADM and DADM. （2） Another 64 rats were divided into ADM group and DADM-1 d, DADM-2 d, and DADM-3 d groups according to the random number table, with 16 rats in each group. A skin flap in size of 2.0 cm × 1.8 cm was raised on the back of each rat. The above-mentioned ADM, DADM-1 d, DADM-2 d, and DADM-3 d were cut into pieces in the size of 1.8 cm×1.5 cm, and they were respectively implanted under the skin flaps of rats in corresponding group. At post surgery week （PSW） 1, 3, 5, or 9, 4 rats in each group were used to observe wound healing condition and change in im- plants with naked eye, and histological observation of the implants was conducted. Data were processed with one-way analysis of variance and t test. Results （1） The freshly prepared DADM was milky white, soft in texture with flexibility, but poor in elasticity as compared with ADM. No epithelial structure or cellular component was observed in ADM or DADM under light microscope. Collagen fibers of DADM were seen to be thickened unevenly and arranged in disorder and eosinophilic. All microbiological results of DADM were negative. There was no statistically significant difference among DADM-1 d, DADM-2 d, and DADM-3 d in levels of ultimate tensile strength, maximum tension, stretched length at breaking, and stress-strain relation- ship （ with F values from 0. 088 to 3. 591, P values all above 0.05 ）. Values of the above-mentioned four in- dexes were the highest in DADM-3 d, they were respectively （ 13.0 ± 2.4） MPa, （61 ± 4） N, （ 175 ± 7）%, （45.7±2.0）%. Values of the four indexes of ADM were respectively （19.0 ±2.6） MPa, （95 ±4） N, （201 ±5）%, （62.5 ±2.2）%, which were higher than those of DADM-1 d, DADM-2 d, and DADM-3 d （with t values from 6. 424 to 17. 125, P values all below 0.01 ）. （2） No exudate or swelling in the wounds of rats, and no contraction or curling of implants were observed in every group at PSW 1, but in- flammatory ceils infiltration and Fbs inward migration were observed in the wound. At PSW 3, the growth of hair was normal in the wound in DADM-1 d, DADM-2 d, and ADM groups, but few and scattered hair grew in DADM-3 d group. The inflammatory cells decreased, while Fbs increased, and new capillaries were found to grow inwardly in each group. The decrease in inflammatory cells was slightly delayed in DADM-3 d group. At PSW 5, hair growth became normal, and implants shrank and thinned with fiber membrane wrapped densely and bundles of ingrowing large caliber blood vessels in all groups. The dermal matrix in each group merged with the surrounding normal tissue. At PSW 9, ADM and DADM became white, thin, and soft tissue sheet which was closely connected with the inner side of the flap. There was no infiltration of inflammatory cells in implants in either group. The collagen fibers arranged regularly and densely, and they were integrat- ed with normal collagen tissue. Conclusions The burned DADM does not have obvious immunogenicity, but with good biocompatibility. It is prospective to become as a dermal substitute in repairing wounds.
出处
《中华烧伤杂志》
CAS
CSCD
北大核心
2012年第3期201-206,共6页
Chinese Journal of Burns
基金
国家重点基础研究发展计划（2005CB522603）
国家自然科学基金面上项目（81071560、30670571、30772258）
山东省科技攻关项目（2009GG1O002078）
关键词
烧伤
细胞外基质
变性真皮
脱细胞真皮基质
创面修复
Burns
Extracellular matrix
Denatured dermis
Acellular dermal matrix
Wound repair
