Effects of probiotics supplementation on skin wound healing in diabetic rats / Suplementação perioperatória com probióticos na cicatrização de feridas cutâneas em ratos diabéticos

ABSTRACT Background: Chronic wounds in patients with Diabetes Mellitus often become incurable due to prolonged and excessive production of inflammatory cytokines. The use of probiotics modifies the intestinal microbiota and modulates inflammatory reactions. Aim: To evaluate the influence of perioperative supplementation with probiotics in the cutaneous healing process in diabetic rats. Methods: Forty-six rats were divided into four groups (C3, P3, C10, P10) according to the treatment (P=probiotic or C=control, both orally administered) and day of euthanasia, 3rd or 10th postoperative days. All rats were induced to Diabetes Mellitus 72 h before starting the experiment with alloxan. Supplementation was initiated five days before the incision and maintained until euthanasia. Scalpel incision was guided by a 2x2 cm mold and the wounds were left to heal per second-intention. The wounds were digitally measured. Collagen densitometry was done with Picrosirius Red staining. Histological parameters were analyzed by staining by H&E. Results: The contraction of the wound was faster in the P10 group which resulted in a smaller scar area (p=0.011). There was an increase in type I collagen deposition from the 3rd to the 10th postoperative day in the probiotic groups (p=0.016), which did not occur in the control group (p=0.487). The histological analysis showed a better degree of healing in the P10 group (p=0.005), with fewer polymorphonuclear (p<0.001) and more neovessels (p=0.001). Conclusions: Perioperative supplementation of probiotics stimulates skin wound healing in diabetic rats, possibly due to attenuation of the inflammatory response and increased neovascularization and type I collagen deposition.

RESUMO Racional: Feridas crônicas em pacientes diabéticos muitas vezes se tornam incuráveis devido à produção prolongada e excessiva de citocinas inflamatórias. A utilização de probióticos modifica a microbiota intestinal e modula reações inflamatórias. Objetivo: Avaliar a influência da suplementação perioperatória com probióticos no processo de cicatrização cutânea em ratos diabéticos. Método: Quarenta e seis ratos foram divididos em quatro grupos (C3, P3, C10, P10) conforme tratamento (P=probiótico ou C=controle, via oral) e dia de eutanásia: 3o ou 10o dia de pós-operatório. Todos os ratos foram induzidos ao diabete melito 72 h antes de iniciar o experimento com aloxana. A suplementação foi iniciada cinco dias antes da operação e mantida até a eutanásia. Foi realizada incisão com bisturi guiada por molde de 2x2 cm e a ferida foi deixada para cicatrizar por segunda intenção. As feridas foram medidas digitalmente. A densitometria de colágeno foi determinada com coloração picrosirius red. A histologia foi avaliada por coloração com H&E. Resultados: A contração da ferida foi maior no grupo P10, o que resultou em menor área cruenta (p=0,011). Houve aumento do colágeno tipo I do 3o para o 10o dia de pós-operatório no grupo P10 (p=0,016), o que não ocorreu no grupo controle (p=0,487). A análise histológica mostrou melhor grau de cicatrização no grupo P10 (p=0,005), com menos polimorfonucleares (p<0,001) e mais neovasos (p=0,001). Conclusões: A suplementação perioperatória de probióticos promove aceleração da cicatrização cutânea em ratos diabéticos, possivelmente por atenuar a resposta inflamatória e aumentar a neovascularização e a deposição de colágeno tipo I.

A prototype single-port device for pressurized intraperitoneal aerosol chemotherapy. Technical feasibility and local drug distribution

Abstract Purpose: To evaluate the technical feasibility and homogeneity of drug distribution of pressurized intraperitoneal aerosol chemotherapy (PIPAC) based on a novel process of intraperitoneal drug application (multidirectional aerosolization). Methods: This was an in vivo experimental study in pigs. A single-port device was manufactured at the smallest diameter possible for multidirectional aerosolization of the chemotherapeutic drug under positive intraperitoneal pressure. Four domestic pigs were used in the study, one control animal that received multidirectional microjets of 9 mL/sec for 30 min and three animals that received multidirectional aerosolization (pig 02: 9 mL/sec for 30 min; pigs 03 and 04: 3 mL/sec for 15 min). Aerosolized silver nitrate solution was applied for anatomopathological evaluation of intraperitoneal drug distribution. Results: Injection time was able to maintain the pneumoperitoneum pressure below 20 mmHg. The rate of moderate silver nitrate staining was 45.4% for pig 01, 36.3% for pig 02, 36.3% for pig 03, and 72.7% for pig 04. Conclusions: Intra-abdominal drug distribution had a broad pattern, especially in animals exposed to the drug for 30 min. Our sample of only four animals was not large enough to demonstrate an association between aerosolization and a higher silver nitrate concentration in the stained abdominal regions.