Banca de DEFESA: ANA CLAUDIA SOUZA ABREU

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA CLAUDIA SOUZA ABREU
DATE: 17/07/2024
TIME: 16:00
LOCAL: Sala virtual google meet
TITLE:

SILVER NANOPARTICLES SYNTHESIZED THROUGH STINGLESS BEE (Melipona compressipes manaosensis) HONEY IN THE TISSUE REPAIR OF INFECTED SKIN WOUNDS IN WISTAR RATS (Rattus novergicus albinus)

KEY WORDS:

Green synthesis. Wound healing. Antimicrobian activity. Toxicity.

PAGES: 140
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

When infected, a skin wound causes a significant delay in the healing process, becoming a public health problem. Due to these problems, stingless bee honey (ASF) promotes several curative therapeutic purposes, mainly antimicrobial and healing, as well as silver nanoparticles (AgNPs) have been used. The objective of this research was to evaluate the tissue repair process of skin wounds infected with Staphylococcus aureus in an in vivo test, through the application of AgNPs synthesized from ASF honeys. 35 samples of ASF honey from rural producers in the state of Amazonas were used. These samples underwent physicochemical and biochemical analyzes and evaluation of antimicrobial activity through the well diffusion assay and Minimum Inhibitory Concentration (MIC) against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Of the 35 samples, two samples called JUP1 and JUP2 from the bee species Melipona compressipes manaosensis were selected, which had the highest antimicrobial activities for carrying out AgNPs synthesis. These AgNPs were characterized using dynamic light scattering (DLS), Zeta Potential (PZ), stability of AgNPs over time and Transmission Electron Microscopy (TEM). Subsequently, the toxicity test of the AgNPs synthesized using the JUP1 and JUP2 samples was carried out, using the in vivo dermal toxicity test. In addition, an in vitro ocular irritation toxicity test was carried out. After carrying out the biosafety tests, the in vivo healing test was started, with 60 rats of the species Rattus novergicus albinus, which had skin wounds infected with Staphylococcus aureus, they will be drawn and distributed into 6 groups of 10 animals, being named as follows: GMJUP1 and GMJUP2 (treatment with Melipona compressipes manaosensis honey); GNJUP1 and GNJUP2 (treatment with AgNPs synthesized from Melipona compressipes manaosensis honey); GCS (treatment with 0.9% physiological sodium chloride solution, characterized as a negative control); GCP (treatment with neomycin sulfate ointment, characterized as a positive control). Afterwards, macroscopic and microscopic analyzes of the wounds were carried out according to the date of euthanasia of the animals (7 and 14 days). The results on the physical-chemical and biochemical analysis of the honeys showed variations between the samples, since the botanical origin, storage conditions, geographic location and others influence the quality of the honeys. The synthesis of AgNPs from samples JUP1 and JUP2 was verified with amber coloration at concentrations of 3 mM and 5 mM at 80ºC and confirmed through the absorbance peak obtained between 400 and 480 nm through surface plasmon resonance (RPS) regarding the formation of AgNPs. Furthermore, similarities were observed between diameters, surface charges and shapes. While in the FTIR spectrum of chemical groups, the presence of phenolic compounds capable of reducing Ag+ ions is suggested. The acute dermal toxicity test did not show any sign of erythema/eschars or edema of AGNPs from JUP1 and AgNPs from JUP2 during the 14 days of observation. In the in vivo microbiological analysis there was variability in the S. aureus count between the groups. In the evolution of the wound perimeter, the AgNPs synthesized through the JUP1 and JUP2 honeys did not differ statistically (p<0.05) from the negative control group and the honey from the JUP1 sample, however they had the greatest wound contractions in relation to the positive control group and honey from sample JUP2 on the 3rd and 7th day. Regarding the fibroblast count between the groups, the GMJUP2 group had greater fibroblast activation compared to the other groups on day 7 and on day 14, the GCS group had greater fibroblast activation. In relation to the deposition of collagen III, the groups had no statistical differences (p>0.05), obtaining little deposition of collagen fibers on days 7 and 14. In relation to type I collagen, there were no statistical differences in themselves ( p>0.05), obtaining a large deposition of collagen fibers on day 7. While on day 14, the type I collagen count had statistical differences between the groups (p>0.05) in relation to collagen production. Despite this variability in the count of fibroblasts and collagen between the groups, there was an organization and alignment of the collagen fibers in the observation of the histological slides from the honey groups and AgNPs synthesized through JUP1 and JUP2 honeys when compared to the negative control.

COMMITTEE MEMBERS:
Presidente - 1770373 - PAULO SERGIO TAUBE JUNIOR
Interno - ***.076.599-** - JUAREZ DE SOUZA - UEPA
Interna - 1334145 - GRACIENE DO SOCORRO TAVEIRA FERNANDES
Externo à Instituição - HUGO NAPOLEÃO PEREIRA DA SILVA - UFOPA
Externo à Instituição - ALAN KELBIS OLIVEIRA LIMA - EMBRAPA