Browsing by Author "Machado, Adriana"
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- Elevating skincare science: grape seed extract encapsulation for dermatological carePublication . Castro, Maria Leonor; Azevedo-Silva, João; Valente, Diana; Machado, Adriana; Ribeiro, Tânia; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar L.; Borges, Sandra; Baptista-Silva, SaraThe skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL−1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of −20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL−1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL−1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.
- A paradigm shift in skincare through the power of grape seed-loaded liposomesPublication . Castro, Maria Leonor de; Azevedo-Silva, João; Valente, Diana; Machado, Adriana; Ribeiro, Tânia; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar; Borges, Sandra; Baptista-Silva, SaraThe skin undergoes natural aging and is prone to various conditions/pathologies due to constant exposure to environmental stressors and abrasions. The cosmetic industry has revolutionized skincare, each time in a higher trend for natural and organic products. The growing trend of clean beauty, driven by consumer demand for non-toxic and environmentally friendly products, is increasingly intertwined with sustainability, as brands and consumers alike prioritize ethical sourcing, eco-conscious packaging, and responsible production practices to reduce environmental impact and promote holistic well-being. Plant-derived natural ingredients are increasingly popular in cosmetic formulations due to their bioactive properties and sustainability. Among these, grape by- products are notable for their bioactive molecules, which exhibit significant biological activities. Utilizing these by-products is crucial, but many bioactive compounds like polyphenols are unstable and prone to degradation. Encapsulation in liposomes has emerged as an effective strategy to enhance their stability, skin penetration, among other characteristics. This study involved the extraction of two grape seed extracts: one from a single grape variety (GSE-Ov) and another from a mixture of five varieties (GSE-Sv). Both extracts were evaluated for their antioxidant and antimicrobial properties, along with their chemical composition and molecular structure. The GSE-Ov extract demonstrated superior antioxidant activity, with a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) IC50 of 0.079 mg/mL. It also showed antimicrobial effects against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), with minimum bactericidal concentrations (MBCs) of 3.125 mg/mL and 6.25 mg/mL, respectively. Furthermore, it did not display any antimicrobial activity against Staphylococcus epidermidis, what promises to not affect the skin microbiota equilibrium. The key polyphenols identified in GSE-Ov included gallic acid, catechin, and procyanidin B1, and FTIR analysis confirmed that the extraction process preserved the extract's molecular integrity. This extract was encapsulated in pectin-coated soy lecithin liposomes, achieving an encapsulation efficiency of 88.8% and a polyphenol release rate of 59.4% over 24 hours. The liposomes were stable, with a zeta potential of -20.3 mV, an average diameter of 13.6 μm, and a uniformity index of 0.637. They were found to be safe under the concentrations of 5 and 2.5 mg/mL in HaCaT and HDF cell models, respectively, and demonstrated anti-inflammatory effects against IL- 1α at 2 mg/mL. This study is an evident first line of research that brings together the potential of grape- seeds as by-products and the clenched systems to encapsulate them. The study addresses all paradigms of eco-conscious innovation, sustainability and circular economy.