Diana Tavares-Valente

Cannabinoids have long been known for their bioactive properties, with their topical application as anti-inflammatory compounds being at the forefront of research for the past decade. Concurrently, the cosmetic market is a fast-growing industry in constant need of new biomolecules. In this work, we studied the safety profile for topical applications of two cannabinoids: cannabidiol (CBD) and cannabigerol (CBG) and assessed their potential as skin care ingredients. The CBG used in this work resulted from bio-fermentation, and to the best of our knowledge, there are no extensive reports on its safety and usage as a cosmetic ingredient. Our results show that CBD and CBG do not exhibit cytotoxicity, mutagenicity, or skin sensitization. Moreover, we verified an absence of primary irritability, accumulated irritability, phototoxicity and photosensitization, supporting the claims of dermatologically tested, hypoallergenic and non-irritating. While these cannabinoids did not show significant anti-aging effects by altering the extracellular matrix components (both in vitro and ex vivo), they demonstrated promise as protective agents against inflammation caused by air pollution. Specifically, they reduced the levels of pro-inflammatory cytokines, making them valuable in combating environmental skin damage. Overall, our results validate the safety of topical use of cannabinoids, while paving the way for further research in the beauty and personal care market as soothing agents.

Cannabigerol (CBG) from Cannabis sativa L. is known for its anti-inflammatory, antibacterial, and antioxidant properties, showing potential against intestinal inflammation. However, its lipophilic nature limits its absorption and stability. Researchers have explored cellulose nanocrystals (CNCs) to deliver lipophilic compounds and enhance their biological outcomes. This study investigated the capability of modified CNC with cetyltrimethylammonium bromide (CTAB) to effectively deliver CBG. The encapsulation process’s impact on cytotoxicity, biological activity, and controlled release during digestion was assessed. Results indicated that CNC-CTAB encapsulation significantly reduced CBG’s cytotoxicity on intestinal cells, allowing safer administration of higher doses. The antioxidant and anti-inflammatory properties of the encapsulated CBG were retained, resulting in a decrease in reactive oxygen species and cytokine levels in intestinal cells. Additionally, the system inhibited the growth of the intestinal pathogen Campylobacter jejuni. The study supports using CNC-CTAB as an efficient delivery system to enhance CBG’s potential against intestinal inflammation. Incorporating this system into food matrices could lead to novel functional foods for managing intestinal inflammation.

The 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.

The 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 carry 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, its encapsulation using nano/microsystems (i.e. liposomes) 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 for their chemical composition and molecular structure. The extract that showed the most promising properties was the GSE-Ov with a DPPH IC₅₀ of 0.079 mg.mL^-1. This extract was encapsulated in soy lecithin liposomes coated with pectin, with an encapsulation efficiency of 88.8%. These 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. Loaded liposomes 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 valorization of a by-product from the wine industry, by using natural extracts in skincare products.

The encapsulation of retinol within silica microparticles has emerged as a promising opportunity in the realm of cosmetic and pharmaceutical formulations, driven by the need to reinforce the photoprotection and oxidation stability of retinol. This work examines the process of encapsulating retinol into silica microparticles. The association efficiency, microparticle size, molecular structure, morphology, oxidation, and release profile, as well as biocompatibility and skin sensitization, were evaluated. Results showed that 0.03% of retinol and 9% of emulsifier leads to an association efficiency higher than 99% and a particle size with an average of 5.2 µm. FTIR results indicate that there is an association of retinol with the silica microparticles, and some may be on the surface. Microscopy indicates that when association happens, there is less aggregation of the particles. Oxidation occurs in two different phases, the first related to the retinol on the surface and the second to the associated retinol. In addition, a burst release of up to 3 h (30% free retinol, 17% associated retinol) was observed, as well as a sustained release of 44% of retinol up to 24 h. Encapsulation allowed an increase in the minimal skin cytotoxic concentrations of retinol from 0.04 μg/mL to 1.25 mg/mL without skin sensitization. Overall, retinol is protected when associated with silica microparticles, being safe to use in cosmetics and dermatology.

Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of less than 10 percent largely due to the intense fibrotic desmoplastic reaction, characterized by high levels of extracellular matrix (ECM) collagen I that constitutes a niche for a subset of cancer cells, the cancer stem cells (CSCs). Cancer cells undergo a complex metabolic adaptation characterized by changes in metabolic pathways and biosynthetic processes. The use of the 3D organotypic model in this study allowed us to manipulate the ECM constituents and mimic the progression of PDAC from an early tumor to an ever more advanced tumor stage. To understand the role of desmoplasia on the metabolism of PDAC parenchymal (CPC) and CSC populations, we studied their basic metabolic parameters in organotypic cultures of increasing collagen content to mimic in vivo conditions. We further measured the ability of the bioenergetic modulators (BMs), 2-deoxyglucose, dichloroacetate and phenformin, to modify their metabolic dependence and the therapeutic activity of paclitaxel albumin nanoparticles (NAB-PTX). While all the BMs decreased cell viability and increased cell death in all ECM types, a distinct, collagen I-dependent profile was observed in CSCs. As ECM collagen I content increased (e.g., more aggressive conditions), the CSCs switched from glucose to mostly glutamine metabolism. All three BMs synergistically potentiated the cytotoxicity of NAB-PTX in both cell lines, which, in CSCs, was collagen I-dependent and the strongest when treated with phenformin + NAB-PTX. Metabolic disruption in PDAC can be useful both as monotherapy or combined with conventional drugs to more efficiently block tumor growth.

The unstoppable growth of human population that occurs in parallel with all manufacturing activities leads to a relentless increase in the demand for resources, cultivation land, and energy. In response, currently, there is significant interest in developing strategies to optimize any available resources and their biowaste. While solutions initially focused on recovering biomolecules with applications in food, energy, or materials, the feasibility of synthetic biology in this field has been demonstrated in recent years. For instance, it is possible to genetically modify Saccharomyces cerevisiae to produce terpenes for commercial applications (i.e., against malaria or as biodiesel). But the production process, similar to any industrial activity, generates biowastes containing promising biomolecules (from fermentation) that if recovered may have applications in different areas. To test this hypothesis, in the present study, the lipid composition of by-products from the industrial production of β-farnesene by genetically modified Saccharomyces cerevisiae are studied to identify potentially bioactive compounds, their recovery, and finally, their stability and in vitro bioactivity. The assayed biowaste showed the presence of triterpenes, phytosterols, and 1-octacosanol which were recovered through molecular distillation into a single fraction. During the assayed stability test, compositional modifications were observed, mainly for the phytosterols and 1-octacosanol, probably due to oxidative reactions. However, such changes did not affect the in vitro bioactivity in macrophages, where it was found that the obtained fraction decreased the production of TNF-α and IL-6 in lipopolysaccharide (LPS)-induced inflammation.

The reverse pH gradient is a major feature associated with cancer cell reprogrammed metabolism. This phenotype is supported by increased activity of pH regulators like ATPases, carbonic anhydrases (CAs), monocarboxylate transporters (MCTs) and sodium–proton exchangers (NHEs) that induce an acidic tumor microenvironment, responsible for the cancer acid-resistant phenotype. In this work, we analyzed the expression of these pH regulators and explored their inhibition in breast cancer cells as a strategy to enhance the sensitivity to chemotherapy. Expression of the different pH regulators was evaluated by immunofluorescence and Western blot in two breast cancer cell lines (MDA-MB-231 and MCF-7) and by immunohistochemistry in human breast cancer tissues. Cell viability, migration and invasion were evaluated upon exposure to the pH regulator inhibitors (PRIs) concanamycin-A, cariporide, acetazolamide and cyano-4-hydroxycinnamate. Additionally, PRIs were combined with doxorubicin to analyze the effect of cell pH dynamic disruption on doxorubicin sensitivity. Both cancer cell lines expressed all pH regulators, except for MCT1 and CAXII, only expressed in MCF-7 cells. There was higher plasma membrane expression of the pH regulators in human breast cancer tissues than in normal breast epithelium. Additionally, pH regulator expression was significantly associated with different molecular subtypes of breast cancer. pH regulator inhibition decreased cancer cell aggressiveness, with a higher effect in MDA-MB-231. A synergistic inhibitory effect was observed when PRIs were combined with doxorubicin in the breast cancer cell line viability. Our results support proton dynamic disruption as a breast cancer antitumor strategy and the use of PRIs to boost the activity of conventional therapy.