Avaliação da eficácia da biomembrana de látex natural incorporada com gentamicina na cicatrização de feridas experimentais em ovinos
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Data
2022-05-13
Autores
Gemeinder, José Lúcio Pádua
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Universidade Estadual Paulista (Unesp)
Resumo
A antibioticoterapia visa reduzir ou eliminar o número de microrganismos presentes na ferida. Os sistemas de liberação de fármacos, como os transdérmicos, são fundamentais para promoção de ações terapêuticas, onde é possível controlar a liberação dos fármacos por um longo período. O látex extraído da seringueira Hevea brasiliensis, um polímero natural, destaca-se por suas propriedades físicas e pela produção de biomembranas. Acerca disto, o objetivo deste estudo visou avaliar diferentes tratamentos de feridas induzidas em ovinos utilizando biomembrana de látex com e sem gentamicina quanto a melhora da cicatrização e redução da carga bacteriana, correlacionando a carga bacteriana e cicatrização, e verificar possíveis alterações dos marcadores bioquímicos de lesão hepatocelular e função renal causadas pelas biomembranas. Para isso, 10 ovinos receberam três ferimentos no hemitórax esquerdo e direito, os quais ficaram expostos por 24 h, a fim de promover contaminação microbiana. Após isso, os animais receberam tratamento, de forma aleatória (randomizada), com cobertura de biomembrana sem e com gentamicina ou não receberam cobertura alguma (grupo controle). Foi realizado a microscopia de força atômica nas biomembranas. As feridas foram avaliadas morfometricamente e quanto a carga bacteriana total, e além disso, foi testada a sensibilidade a diferentes antimicrobianos e às próprias biomembranas. Foi realizada avaliação hematológica e bioquímica para verificar alterações renais e hepáticas. Foi verificado o processo cicatricial por análises histológicas nos momentos dia zero (M0), dia treze (M13) e dia vinte e cinco (M25). As diferenças entre os tratamentos foram verificadas pelo teste de ANOVA com pós-teste de Tukey ou Friedman com pós-teste de Dunn, e as correlações foram realizadas pelos coeficientes de Pearson ou Spearman. Observou-se uma superfície uniforme com presença de grânulos nas biomembranas sem fármaco e nas incorporadas a dispersão homogênea do fármaco, não alterando a estrutura da superfície. As biomembranas com ou sem associação do antibiótico não aceleraram o processo de cicatrização de feridas cutâneas em ovinos. O tamanho das feridas tratadas reduziu em 40% em 7 dias e o fechamento total ocorreu em 25 dias. Os testes hematológicos e bioquímicos não apresentaram alterações relevantes, nem renais e hepáticas. Não houve correlação entre o tamanho da ferida e a carga bacteriana. Das 121 colônias isoladas, as mais frequentes foram Staphylococcus coagulase negativa (50,41%). A biomembrana de látex com gentamicina promoveu redução da carga bacteriana sem indução de resistência antimicrobiana. Observou-se aumento da inflamação no M13 da ferida controle e no M13 e M25 dos tratamentos com a biomembrana de látex e de látex incorporado com gentamicina. A biomembrana incorporada com o antimicrobiano promoveu melhor aparência macroscópica da cicatrização sem evidência de cicatrizes hipertróficas e queloides.
The antibiotic therapy aims to reduce or eliminate the number of microorganisms living in the wound. The releasing system of drugs, like transdermal ones, are fundamental for the promotion of therapeutical actions, which make it possible to control the release of drugs for a long period. The latex extract from the rubber tree Hevea brasiliensis, a natural polymer, stands out for its physical features and for the production of biomembranes. Hereof, the objective of this study aims to evaluate different treatments of experimental wounds in ovine using latex biomembranes with or without gentamicin in relation to the improvement of healing and reduction of the of bacteria, correlating to the load of bacteria and wound healing, checking possible alterations of the biochemistry markers of hepatocellular injuries and renal functions caused by the biomembranes. To this end, 10 ovine received three wounds in their left and right hemithorax, which were exposed for 24 hours, aiming to promote macrobiotics contamination. After that, the animals received treatment, in a random way, with the coverage of the biomembrane with or without the gentamicin or didn’t receive any coverage (control group). Atomic force microscopy was conducted in the biomembranas. The wounds were evaluated morphometrically in relation to the total load of bacteria, and besides that, the sensibility was tested to different antimicrobials and to the biomembranes themselves. Hematologic and biochemistry evaluation was made in order to check renal and liver changes. The healing process was verified through histological analyses in the moments day zero(M0), day thirteenth (M13) and day twenty-fifth(M25). The differences between the treatments were verified by the ANOVA test with post-test of Tukey or Friedman with post-test of Dunn, and the correlations were made by the coefficients of Pearson or Spearman. An even surface containing granules was seen in the biomembranes without drugs and in the incorporated ones a homogeneous dispersion of the drugs was observed, which didn’t change the aspect of the surface. The biomambranes with or without the association of the antibiotics didn’t accelerate the healing process of skin wounds in ovine. The size of the wounds treated was reduced by 40% in 7 days and the total healing of the wounds happened in 25 days. The hematological and biochemical tests didn’t show significant changes, neither renal nor hepatic. There wasn’t correlation between the size of the wound and the bacterial load. From the 121 isolated colonies, the more frequent ones were Staphylococcus with negative coagulases (50,41%). The latex biomembrane with gentamicin promoted the reduction of the bacterial load without the induction of antimicrobial resistance. It was observed an increase in the inflammation in M13 of the wound control and in M13 and M25 of the treatments using the latex biomembrane and with latex incorporated to gentamicin. The incorporated biomembrane with antimicrobials promoted better macroscopic aspect of the healing with no evidence of hypertrophic scars or keloids.
The antibiotic therapy aims to reduce or eliminate the number of microorganisms living in the wound. The releasing system of drugs, like transdermal ones, are fundamental for the promotion of therapeutical actions, which make it possible to control the release of drugs for a long period. The latex extract from the rubber tree Hevea brasiliensis, a natural polymer, stands out for its physical features and for the production of biomembranes. Hereof, the objective of this study aims to evaluate different treatments of experimental wounds in ovine using latex biomembranes with or without gentamicin in relation to the improvement of healing and reduction of the of bacteria, correlating to the load of bacteria and wound healing, checking possible alterations of the biochemistry markers of hepatocellular injuries and renal functions caused by the biomembranes. To this end, 10 ovine received three wounds in their left and right hemithorax, which were exposed for 24 hours, aiming to promote macrobiotics contamination. After that, the animals received treatment, in a random way, with the coverage of the biomembrane with or without the gentamicin or didn’t receive any coverage (control group). Atomic force microscopy was conducted in the biomembranas. The wounds were evaluated morphometrically in relation to the total load of bacteria, and besides that, the sensibility was tested to different antimicrobials and to the biomembranes themselves. Hematologic and biochemistry evaluation was made in order to check renal and liver changes. The healing process was verified through histological analyses in the moments day zero(M0), day thirteenth (M13) and day twenty-fifth(M25). The differences between the treatments were verified by the ANOVA test with post-test of Tukey or Friedman with post-test of Dunn, and the correlations were made by the coefficients of Pearson or Spearman. An even surface containing granules was seen in the biomembranes without drugs and in the incorporated ones a homogeneous dispersion of the drugs was observed, which didn’t change the aspect of the surface. The biomambranes with or without the association of the antibiotics didn’t accelerate the healing process of skin wounds in ovine. The size of the wounds treated was reduced by 40% in 7 days and the total healing of the wounds happened in 25 days. The hematological and biochemical tests didn’t show significant changes, neither renal nor hepatic. There wasn’t correlation between the size of the wound and the bacterial load. From the 121 isolated colonies, the more frequent ones were Staphylococcus with negative coagulases (50,41%). The latex biomembrane with gentamicin promoted the reduction of the bacterial load without the induction of antimicrobial resistance. It was observed an increase in the inflammation in M13 of the wound control and in M13 and M25 of the treatments using the latex biomembrane and with latex incorporated to gentamicin. The incorporated biomembrane with antimicrobials promoted better macroscopic aspect of the healing with no evidence of hypertrophic scars or keloids.
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Palavras-chave
Biomembrana de látex natural, Liberação sustentada, Atividade antimicrobiana, Biomaterial, Liberação de Fármaco