Characterization and assessment of the genotoxicity and biocompatibility of poly (hydroxybutyrate) and norbixin membranes

Abstract Purpose To synthesize and characterize poly(hydroxybutyrate) (PHB) and norbixin membranes to evaluate them for genotoxicity in rats and wound healing in mice by histological staining. Methods For the evaluation of genotoxicity, male rats ( Rattus novegicus ) were divided into three groups (n= 5): 5% PHB/Norbixin membrane introduced into the peritoneum by laparotomy; B - negative control; C - positive control (intraperitoneal dose of cyclophosphamide 50 mg/kg). For the evaluation of biocompatibilty, a cutaneous wound was induced on the back of males mice ( Mus musculus ) divided into two experimental treatment groups: control and membrane that underwent euthanasia after 7 and 14 days treatment. Statistical analysis ware made by One Way Anova post hoc Tukey Test (p<0.05). Results Regarding the incidence of polychromatic erythrocytes, there was no difference between negative control and 5% PHB/Norbixin membrane; however, when compared to the positive control represented by cyclophosphamide, there was a significant difference (p <0.001). As for DNA damage, the changes induced in the first 4h were repaired in 24h. In addition, the membrane was effective in abbreviating the inflammatory process and served as a scaffold due to the stimulus to reepithelialization mainly on the 7 days of treatment. Conclusion The non-genotoxic PHB/Norbixin 5% membrane presented promising results that suggest its effectiveness as a guide for tissue regeneration given its biocompatibility.

Effect of norbixin-based poly(hydroxybutyrate) membranes on the tendon repair process after tenotomy in rats

Abstract Purpose: To determine the efficacy of norbixin-based poly(hydroxybutyrate) (PHB) membranes for Achilles tendon repair. Methods: Thirty rats were submitted to total tenotomy surgery of the right Achilles tendon and divided into two groups (control and membrane; n = 15 each), which were further subdivided into three subgroups (days 7, 14, and 21; n = 5 each). Samples were analyzed histologically. Results: Histological analysis showed a significant reduction in inflammatory infiltrates on days 7, 14 (p < 0.0001 for both), and 21 (p = 0.0004) in the membrane group compared to that in the control group. There was also a significant decrease in the number of fibroblasts in the control group on days 7, 14 (p < 0.0001), and 21 (p = 0.0032). Further, an increase in type I collagen deposition was observed in the membrane group compared to that in the control group on days 7 (p = 0.0133) and 14 (p = 0.0107). Conclusion: Treatment with norbixin-based PHB membranes reduces the inflammatory response, increases fibroblast proliferation, and improves collagen production in the tendon repair region, especially between days 7 and 14.

Ação cicatrizante da nanopartícula de prata com norbixina em queimaduras / Healing action of silver nanoparticle with norbixin on burns

Introdução: A queimadura é uma injúria que altera a integridade da pele, decorrente de traumas térmicos. Dentre os compostos não convencionais utilizados na cicatrização de feridas estão a norbixina e as preparações com prata. Objetivo: avaliar a ação cicatrizante da nanopartícula de prata associada à norbixina em queimaduras de Mus musculus. Métodos: Inicialmente, preparou-se uma solução nanoprata/norbixina e a partir desta obteve-se o gel teste. Posteriormente dividiu-se os animais em 3 grupos, sendo negativo (sem tratamento), positivo (sulfadiazina de prata) e teste (gel teste). Nestes animais houve a indução das queimaduras. No 7º e 14º dia realizou-se a eutanásia e os tecidos lesionados foram coletados para análise microscópica. Resultado: Verificou-se potencial vantagem do grupo teste em relação ao negativo e igualdade comparada ao positivo. Conclusão: A nanopartícula de prata associada à norbixina representa uma fonte alternativa para a cicatrização de queimaduras. (AU)

Introduction: Burning is an injury that alters the integrity of the skin, due to thermal trauma. Among the non-conventional compounds used in wound healing are norbixin and silver preparations. Objective: to evaluate the cicatrizing action of silver nanoparticle associated with norbixina in Mus musculus burns. Methods: Initially, a nanoprata / norbixin solution was prepared and from this solution the test gel was obtained. Afterwards the animals were divided into 3 groups, being negative (without treatment), positive (silver sulfadiazine) and test (gel test). In these animals, there was the induction of burns. On the 7th and 14th day, euthanasia was performed and the injured tissues were collected for microscopic analysis. Result: There was a potential advantage of the test group in relation to negative and equality compared to positive. Conclusion: The silver nanoparticle associated with norbixin represents an alternative source for the healing of burns. (AU)

Efeitos da fotobiomodulação nas alterações extrapulmonares ocasionadas pelo enfisema experimental em rattus norvegicus / Effect of photobiomodulation in extrapulmonary changes caused by experimental emphysema in rattus norvegicus

O enfisema pulmonar é um processo inflamatório pulmonar e tem repercussões extrapulmonares. Os objetivos desta pesquisa são investigar os efeitos da fotobiomodulação nas alterações extrapulmonares. Foram selecionados 24 ratos, divididos em três grupos de 8 animais: grupo controle (GC: recebeu apenas solução salina); grupo DPOC (GD: instilação de papaína 2 mg/kg); grupo DPOC + laser (GDL: instilação de papaína + 15 dias de laserterapia). Para análise dos dados foi coletado e observado: CKMB, LBA, Histologia (análise morfométrica) e espessura das câmaras cardíacas (análise morfométrica), respectivamente. Houve diminuição no número de células inflamatórias no LBA do GDL (p < 0,05) quando comparado com GC e GD; aumento dos níveis de CKMB no grupo GD (p < 0,05); e diminuição significativa no GDL (p = 0,0009) quando comparado com o GD, hipertrofia ventricular esquerda (p < 0,05) no grupo GD e GDL quando comparado com controle. A fotobiomodulação diminui a liberação de células inflamatórias responsáveis pela liberação do CKMB na corrente sanguínea, diminuindo assim os níveis de CKMB e reduzindo os riscos de infarto do miocárdio.

Lung emphysema is a pulmonary inflammatory process, with extrapulmonary repercussions. Twenty-four rats were selected and divided into three groups with eight animals each: control (GC: received only saline solution); group DPOC (GD: with instillation of papaya proteinase 2 mg/kg); group DPOC + laser (GDL: with instillation of papaya proteinase + 15 days of laser therapy). Data analysis comprised: CKMB, LBA, Histology (morphometric analysis) and thickness of the cardiac chambers (morphometric analysis), respectively. The number of inflammatory cells in LBA of GDL decreased (p < 0.05) when compared with GC and GD; there was an increase in CKMB levels in group GD (p < 0.05); significant decrease in GDL (p = 0.0009) when compared to GD, left ventricle hypertrophy (p < 0.05) in group GD and GDL when compared to control. Photobiomodulation decreased the release of inflammatory cells by the release of CKMB in the blood and decreased CKMB levels and reduced myocardial infarction risks.