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Protagonismo das lectinas em nanoformulações: qual a abordagem?
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Resumo(s)
As nanoformulações são formulações farmacêuticas constituídas por nanopartículas de 200 a 500 nm. Elas permitem a encapsulação, conjugação ou adsorção de fármacos que são fracamente absorvidos, possuem baixa biodisponibilidade, são altamente degradados pelo organismo ou que possuem elevada toxicidade. As nanopartículas protegem o fármaco até atingir o seu alvo, melhorando significativamente a sua eficácia e perfil de libertação.
As lectinas são proteínas cuja função é o reconhecimento e ligação a estruturas glicídicas. Estas ligações medeiam interações entre células, síntese de glicoproteínas e possuem funções reguladoras. Por serem ligações comuns no corpo e apresentarem alta afinidade e alguma especificidade, poderão ser aproveitadas para servirem como ligandos nas nanopartículas.
Todas as células expressam à sua superfície receptores e hidratos de carbono, o que possibilita a construção de nanopartículas específicas a um tipo celular. Para mais, uma célula maligna poderá apresentar padrões alterados de receptores ou expressão glicosídica, comparado a uma célula normal. Estas diferenças entre células são exploradas pelas nanopartículas para a entrega do fármaco. As nanopartículas conjugadas a lectinas/hidratos de carbono vão ter uma afinidade específica ao interagirem com as estruturas e receptores da célula-alvo.
Esta monografia irá abordar várias nanopartículas desenvolvidas até agora, no uso em terapia e diagnóstico, e as consequências e prospectivas das nanopartículas como formulações farmacêuticas do futuro.
Nanoformulations are drug delivery systems that consist in nanoparticles whose sizes can range from 200 to 500 nm. They allow the encapsulation, conjugation or adsorption of drugs that are poorly absorbed, have low bioavailability, are degraded in the body or possess high toxicity. Nanoparticles protect the drug until it reaches its target, which improves their efficiency and release profile. Lectins are proteins that recognize and bind to sugar moieties. These bonds mediate cell-to-cell interactions, glycoprotein synthesis and have regulating functions. Because lectin-carbohydrate interactions are very common and have high affinity and some specificity, they can be used as nanoparticle ligands. All cells have carbohydrates and receptors at their surfaces. This allows the making of nanoparticles that are very specific to a type of cell. Furthermore, a malignant cell expresses different glycosylation patterns or receptors than a healthy cell. These differences between cells are exploited by the nanoparticles for drug-delivery. These lectin/carbohydrate conjugated nanoparticles are going to bind specifically to the structures and receptors of their target cells. This monograph will discuss several nanoparticles that have so far been developed for therapy and diagnostics, and the consequences and prospective of nanoparticles as the drug delivery system of the future.
Nanoformulations are drug delivery systems that consist in nanoparticles whose sizes can range from 200 to 500 nm. They allow the encapsulation, conjugation or adsorption of drugs that are poorly absorbed, have low bioavailability, are degraded in the body or possess high toxicity. Nanoparticles protect the drug until it reaches its target, which improves their efficiency and release profile. Lectins are proteins that recognize and bind to sugar moieties. These bonds mediate cell-to-cell interactions, glycoprotein synthesis and have regulating functions. Because lectin-carbohydrate interactions are very common and have high affinity and some specificity, they can be used as nanoparticle ligands. All cells have carbohydrates and receptors at their surfaces. This allows the making of nanoparticles that are very specific to a type of cell. Furthermore, a malignant cell expresses different glycosylation patterns or receptors than a healthy cell. These differences between cells are exploited by the nanoparticles for drug-delivery. These lectin/carbohydrate conjugated nanoparticles are going to bind specifically to the structures and receptors of their target cells. This monograph will discuss several nanoparticles that have so far been developed for therapy and diagnostics, and the consequences and prospective of nanoparticles as the drug delivery system of the future.
Descrição
Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2017
Palavras-chave
Lectinas Nanoformulação Nanopartículas Mucoadesão Hidratos de carbono Mestrado Integrado - 2017