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Desenvolvimento de nanopartículas lipídicas contendo quercetina e ómega-3: avaliação do seu potencial antioxidante
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Abstract(s)
A nossa pele está constantemente sujeita a agressões provocadas por agentes externos, como por exemplo radiação ultravioleta (UV), microrganismos e produtos químicos oxidantes, o que pode resultar num aumento do stress oxidativo. Este desequilíbrio entre a produção e a eliminação das espécies reativas de oxigénio (ROS, do inglês Reactive Oxygen Species) provoca, ao longo do tempo, danos e, consequentemente, o envelhecimento cutâneo. Uma solução possível para ultrapassar a ação destes agentes e, consequentemente, o fenómeno de stress oxidativo é o recurso a agentes protetores cutâneos, os quais podem protegem a pele da ação dos ROS. A quercetina (Q) e os ácidos gordos ómega-3 (ω3) são dois compostos bioativos que apresentam efeitos protetores cutâneos bem reportados na literatura científica, incluindo a atividade antioxidante. No entanto, ambos os compostos bioativos apresentam propriedades que limitam os seus efeitos aquando da aplicação tópica, como seja a dificuldade de permeação cutânea e a instabilidade química. Com o objetivo de superar estas limitações foram desenvolvidos, através de uma abordagem da utilização de um sistema de veiculação duplo, hidrogeles (HGs) de carbómero enriquecidos com vetores lipídicos nanoestruturados (NLCs, do inglês Nanostructured Lipid Carriers) para a administração tópica de Q e/ou ω3 com o intuito de melhorar a sua estabilidade e a permeação cutânea, permitindo um aumento dos efeitos benéficos cutâneos destes bioativos. Foram preparadas duas formulações de NLCs, ambas com a mesma composição lipídica, mas com diferentes agentes tensioativos (os NLC1, contendo lecitina de soja e Poloxamer 407, e os NLC2, contendo Tween® 80 e dioctilsulfossuccinato de sódio (DOSS)). Estes agentes tensioativos demonstraram influenciar o desempenho terapêutico das formulações dos NLCs devido às suas propriedades físico-químicas. Apesar de ambas as formulações de NLCs apresentarem elevada capacidade de carga da Q, as propriedades físico-químicas da formulação dos NLC2 foram consideradas as mais adequadas para aplicação tópica na pele e asseguram uma maior estabilidade coloidal. Adicionalmente, os NLC2 demonstraram uma libertação mais prolongada da Q e ainda apresentaram uma melhor encapsulação e proteção da Q, ao mesmo tempo ainda apresentou melhor permeabilidade do que as outras formulações testadas. O efeito oclusivo dos HGs como sistema de veiculação dos NLCs também tem um impacto positivo na permeação cutânea. Os HGs-NLC2 contendo Q, com ou sem ω3, demonstraram ser mais eficazes como formulações antioxidantes e foto-protetoras. Adicionalmente, estas formulações apresentaram um efeito antibacteriano ao reduzir o crescimento de Staphylococcus aureus. Estes resultados sugerem que a utilização dos HGs enriquecidos com NLC2 constituem uma abordagem promissora para a administração cutânea, com potencial para prevenir o envelhecimento da pele e outros processos cutâneos decorrentes dos danos provenientes do stress oxidativo.
Our skin is constantly subjected to aggression from external agents, such as ultraviolet (UV) radiation, microorganisms, and oxidizing chemicals, which can result in an increase of oxidative stress. This imbalance between the production and elimination of reactive oxygen species (ROS) cause damage over time and, consequently, leads to skin aging. One possible solution to overcome the effect of these aggressive agents and, consequently, the phenomenon of oxidative stress is to use skin protection agents, which can protect the skin from the action of ROS. Quercetin (Q) and omega-3 fatty acids (ω3) are bioactive compounds that have well-known skin protective benefits reported in scientific literature, including antioxidant activity. However, both compounds have properties that limit their effects when applied topically, such as their low chemical stability and difficulty in skin permeation). In order to overcome these limitations, carbomer hydrogels (HGs) enriched with nanostructured lipid carriers (NLCs) for the topical administration of Q and/or ω3 were developed using a dual vehicle system approach, with the aim of improving their stability and skin permeation, allowing for an increase in the beneficial cutaneous effects of these bioactive compounds. Two formulations of NLCs were prepared, both with the same lipid composition, but with different surfactants (NLC1, containing soya lecithin and poloxamer 407, and NLC2, containing Tween® 80 and dioctyl sodium sulphosuccinate (DOSS)). These surfactants were shown to influence the therapeutic performance of the NLC formulations due to their physic-chemical properties. Although both NLC formulations had a high Q-loading capacity, the physicochemical properties of the NLC2 formulation proved to be the most suitable for topical use on the skin and ensured greater colloidal stability. Additionally, NLC2 demonstrated a more prolonged release of Q, indicating a greater storage capacity while improving its permeability. The occlusive effect of HGs as a vehicle system for NLCs also had a positive impact on skin permeation. HGs-NLC2 loaded with Q, with or without ω3, demonstrated to be more effective as antioxidant and photoprotective formulations. Moreover, these formulations showed an antibacterial effect by reducing the growth of Staphylococcus aureus. These results suggest that the use of HGs enriched with NLC2 is a promising approach for skin administration, with the potential to prevent skin ageing and other skin processes resulting from oxidative stress damage.
Our skin is constantly subjected to aggression from external agents, such as ultraviolet (UV) radiation, microorganisms, and oxidizing chemicals, which can result in an increase of oxidative stress. This imbalance between the production and elimination of reactive oxygen species (ROS) cause damage over time and, consequently, leads to skin aging. One possible solution to overcome the effect of these aggressive agents and, consequently, the phenomenon of oxidative stress is to use skin protection agents, which can protect the skin from the action of ROS. Quercetin (Q) and omega-3 fatty acids (ω3) are bioactive compounds that have well-known skin protective benefits reported in scientific literature, including antioxidant activity. However, both compounds have properties that limit their effects when applied topically, such as their low chemical stability and difficulty in skin permeation). In order to overcome these limitations, carbomer hydrogels (HGs) enriched with nanostructured lipid carriers (NLCs) for the topical administration of Q and/or ω3 were developed using a dual vehicle system approach, with the aim of improving their stability and skin permeation, allowing for an increase in the beneficial cutaneous effects of these bioactive compounds. Two formulations of NLCs were prepared, both with the same lipid composition, but with different surfactants (NLC1, containing soya lecithin and poloxamer 407, and NLC2, containing Tween® 80 and dioctyl sodium sulphosuccinate (DOSS)). These surfactants were shown to influence the therapeutic performance of the NLC formulations due to their physic-chemical properties. Although both NLC formulations had a high Q-loading capacity, the physicochemical properties of the NLC2 formulation proved to be the most suitable for topical use on the skin and ensured greater colloidal stability. Additionally, NLC2 demonstrated a more prolonged release of Q, indicating a greater storage capacity while improving its permeability. The occlusive effect of HGs as a vehicle system for NLCs also had a positive impact on skin permeation. HGs-NLC2 loaded with Q, with or without ω3, demonstrated to be more effective as antioxidant and photoprotective formulations. Moreover, these formulations showed an antibacterial effect by reducing the growth of Staphylococcus aureus. These results suggest that the use of HGs enriched with NLC2 is a promising approach for skin administration, with the potential to prevent skin ageing and other skin processes resulting from oxidative stress damage.
Description
Keywords
Quercetina Ácidos gordos ómega-3 (ω3) Vetores lipídicos nanoestruturados (NLCs) Atividade antioxidante Foto-proteção Atividade antimicrobiana Quercetin Omega-3 fatty acids (ω3) Nanostructured lipid carriers (NLCs) Antioxidant activity Photoprotection Antimicrobial activity