UNASSIGNED: Sixteen rabbits were distributed into four groups (n = 4). Except for group 1 (G1), which received only PBS, the other three groups (G2, G3, and G4) were initially challenged with 10 μg of L. intermedia venom, diluted in 100 μL of NaCl 0.9%, by intradermic injection in the interscapular region. Thirty minutes after the challenge all groups were treated with secretome, except for group 2. Group 1 (G1-control group) received intradermal injection (ID) of 60 μg of secretome in 0.15 M PBS; Group 2 (G2) received 0.9% NaCl via ID; Group 3 (G3) received 60 μg of secretome, via ID and Group 4 (G4), received 60 μg of secretome by intravenous route. Rabbits were evaluated daily and after 15 days were euthanized, necropsied and skin samples around the necrotic lesions were collected for histological analysis.
UNASSIGNED: Rabbits of G1 did not present edema, erythema, hemorrhagic halo, or necrosis. In animals from G2, G3, and G4, edema appeared after 6h. However, minor edema was observed in the animals of G2 and G3. Hemorrhagic halo was observed in animals, six hours and three days after, on G2, G3, and G4. Macroscopically, in G4, only one animal out of four had a lesion that evolved into a dermonecrotic wound. No changes were observed in the skin of the animals of G1, by microscopic evaluation. All animals challenged with L. intermedia venom showed similar alterations, such as necrosis and heterophilic infiltration. However, animals from G4 showed fibroblast activation, early development of connective tissue, neovascularization, and tissue re-epithelialization, indicating a more prominent healing process.
UNASSIGNED: These results suggest that secretome from mesenchymal stromal cells cultured in a xeno-free and human component-free culture media can be promising to treat dermonecrosis caused after Loxosceles spiders bite envenoming.
■将16只兔分为4组(n=4)。除第1组(G1)外,只收到PBS,其他三组(G2,G3和G4)最初用10μg中间乳杆菌毒液攻击,在100μL0.9%NaCl中稀释,通过在肩胛骨区域进行皮内注射。攻击后30分钟,所有组都用分泌组治疗,除了第2组。第1组(G1-对照组)接受在0.15MPBS中的60μg分泌体的皮内注射(ID);第2组(G2)通过ID接受0.9%NaCl;第3组(G3)接受60μg分泌体,通过ID和组4(G4),通过静脉途径接受60μg的分泌体。每天对兔子进行评估,15天后实施安乐死,收集坏死病灶周围的尸检和皮肤样本进行组织学分析.
■G1兔没有出现水肿,红斑,出血性光环,或坏死。在来自G2、G3和G4的动物中,在6h后出现水肿。然而,在G2和G3的动物中观察到轻微的水肿。在动物中观察到出血性光环,六小时零三天后,在G2、G3和G4上。宏观上,在G4中,4只动物中只有1只出现了演变为皮肤坏死伤口的病变.通过显微镜评估,在G1的动物的皮肤中没有观察到变化。所有受到中间乳杆菌毒液攻击的动物都表现出相似的改变,如坏死和异源性浸润。然而,来自G4的动物显示成纤维细胞活化,结缔组织的早期发育,新生血管形成,组织再上皮化,表明一个更突出的愈合过程。
■这些结果表明,在无异种和无人类成分的培养基中培养的间充质基质细胞的分泌组有希望治疗Loxsqueles蜘蛛咬伤后引起的皮肤坏死。