Título:	Desenvolvimento de lipossomas vegetais com múltiplas funções biológicas aprisionados em hidrogéis
Autor(es):	Pereira, Tatiane de Melo
Orientador(es):	Silva, Luciano Paulino da
Assunto:	Lipossomas Metabólitos secundários Bioatividade
Data de publicação:	24-Jan-2024
Data de defesa:	29-Set-2023
Referência:	PEREIRA, Tatiane de Melo. Desenvolvimento de lipossomas vegetais com múltiplas funções biológicas aprisionados em hidrogéis. 2023. 174 f., il. Tese (Doutorado em Biologia Molecular) — Universidade de Brasília, Brasília, 2023.
Abstract:	Liposomes are concentric vesicles formed by phospholipids, and find applications in various industries, including pharmaceuticals, food, and agriculture, often serving as carriers for isolated compounds. This study aimed to extract phospholipids from fresh botanical materials and formulate liposomes for transporting extracts of the same botanical origin to confer antimicrobial and antioxidant activities without adverse effects on eukaryotic cells for future topical applications. Using a previously patented adapted technology, phospholipids were successfully extracted from the leaves and stems of 20 plant species, with at least 17 of them allowing for liposome formulation, either containing water (Empty Liposome - LpV) or extract (Loaded Liposome - LpC). An advantage of this method is the absence of membrane extrusion or other uniformization techniques, making liposome production more accessible. Raman spectroscopy confirmed liposome formation in LpV, further substantiated by the presence of phospholipids in nanostructures via thermogravimetry. These nanoformulations were tested against Escherichia coli and Staphylococcus aureus, with only four of them showing activity against S. aureus. Among these, liposomes carrying lavender and oregano extracts at a concentration of 250 mg/mL demonstrated antimicrobial and antioxidant potential, preserving eukaryotic cell viability. In yeast Saccharomyces cerevisiae assays, lavender and oregano LpC exhibited fungistatic activity, whereas free extracts did not, and only oregano LpC displayed fungicide activity. The encapsulation rates for lavender and oregano LpC were found to be 56.33% and 91.70%, respectively. Atomic force microscopy confirmed the presence of concentric structures consistent with liposome formation. To enhance liposome stability and sustained delivery, a hydrogel was formulated with 3% agarose and 2.5% carboxymethyl cellulose. This hydrogel exhibited suitable swelling behavior for therapeutic applications, particularly topical ones, and showed activity against S. aureus. Dialysis membrane release testing revealed that the hydrogel required 35 hours to release 90% of the liposomal content, maintaining sustained release at relatively constant rates for most of the time. Based on these results, it was possible to formulate liposomes of 100% plant origin with antimicrobial activity (against Gram-positive bacteria and yeast), antioxidant activity, and no toxicity to eukaryotic cells.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB) Departamento de Biologia Celular (IB CEL)
Informações adicionais:	Tese (doutorado) — Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Programa de Pós-Graduação em Biologia Molecular, 2023.
Programa de pós-graduação:	Programa de Pós-Graduação em Biologia Molecular
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.unb.br, www.ibict.br, www.ndltd.org sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra supracitada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
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