ALICE - Associate Laboratory in Chemical Engineering

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Cytinus hypocistis (L.) L. extract effects in an animal model of papillomavirus-induced neoplasia

Publication . Medeiros, Catarina; Silva, Ana Rita; Ferreira, Tiago; Barros, Lillian; Neuparth, Maria João; Peixoto, Francisco P.; Bastos, Margarida M.S.M.; Medeiros, Rui; Costa, Rui Miguel Gil; Pires, Maria João; Faustino-Rocha, Ana; Gama, Adelina; Oliveira, Paula A.

Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeutic compounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals, 30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/ n+CH12.4); V (HPV+control) and VI (FVB/n+control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.

2023Journal article

Open access

Saponin-based natural nanoemulsions as alpha-tocopherol delivery systems for dermal applications

Publication . Schreiner, Tatiana B.; Santamaria-Echart, Arantzazu; Colucci, Giovana; Plasencia, Paula; Costa, Patrícia Santos; Dias, Madalena M.; Pinho, Simão; Barreiro, M.F.

Nanoemulsions can be produced using simple methods and compounds from natural sources. They can increase water dispersibility and bioavailability and optimise active ingredient dispersion in particular skin layers. Lipophilic compounds of the vitamin E family (tocopherols and tocotrienols) are well-known for their high antioxidant activity and capacity to protect the skin from oxidative stress. In this context, oil-in-water (o/w) nanoemulsions with and without α-tocopherol (Vitamin E, VE) were formulated with two emulsifier alternatives, Quillaja saponin (QS), and a combination of QS with Tribulus terrestris (QSTT) (50/50, w/w). The emulsions were evaluated concerning stability, microstructure, droplet size, colour attributes, encapsulation efficiency, UV photostability, antioxidant activity, and in vitro permeation studies to assess the delivery potential. Results showed highly stable systems, with round-shape droplets of 80–121 nm size. QS and QSTT samples’ colours were close to white and light brownish, respectively. The topical nano cream had the capacity to entrap VE, producing a protective effect from UV degradation, and very significant antioxidant activity, with IC50 values around 0.01 %wt. The skin permeation profiles showed the efficiency of the formulations in the delivery of VE, with permeabilities between 64 and 74 μg/cm2, while the control sample showed no VE permeation.

2023Journal article

Open access

3D printed photopolymer derived carbon catalysts for enhanced wet peroxide oxidation

Publication . Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Henrique, Adriano; Roman, Fernanda; Omralinov, Daria; Steldinger, Hendryk; Gläsel, Jan; Etzold, Bastian J.M.; Silva, José A.C.; Silva, Adrián; Pereira, Ana I.; Gomes, Helder

In this paper, we explore the application of powdered carbon and 3D-printed carbon monoliths prepared by carbonization of a tailored photopolymer. We demonstrate the efficiency of the developed carbonaceous samples in removing paracetamol (PCM) and sulfamethoxazole (SMX), used as model contaminants. Our results demonstrate that carbon samples are active in CWPO, and their catalytic activity is significantly improved by applying nitric acid and urea functionalization methods. The characterization results showed the pure carbon nature of the material (no ashes), their unique structure defects proven by Raman (D/G > 1.8), textural properties (SBET = 291–884 m2/g) and their surface chemistry, which was addressed by pHPZC (2.5–7.5), acidity (312–2375 μ mol gcat 􀀀 1) and basicity (117–653 μ mol gcat 􀀀 1) determination and XPS of highlighted materials (N1s = 0–3.51 at.%, O1s = 7.1–15.3 at.%). Using desorption assays, our study reveals the adsorption role for pollutant degradation by CWPO using carbon monolithic samples. At last, we demonstrated the ability of functionalized 3D-printed carbon monoliths to keep degradation of PCM and total organic carbon (TOC) above 85 % and 80 %, respectively, during 48 h in a continuous flow CWPO system. Sulfamethoxazole degradation in continuous system was also studied to validate the catalyst versatility, achieving 81 % and 79 % pollutant degradation and TOC abatement, respectively, during 48 h on stream. The characterization of the recovered catalyst provides further insights into the absence of structural modifications after the reaction, reinforcing the stability and reusability characteristic of the 3D-printed carbon catalyst.

2024Journal article

Open access

Unveiling Key Parameters: Time Windows and Travel Times in Capacitated Waste Collection

Publication . Silva, Adriano S.; Lima, José; Silva, Adrián; Gomes, Helder; Pereira, Ana I.

Numerous studies in waste management propose solutions to the Waste Collection Problem, often focusing on constraints such as time windows and truck capacity. Travel times between points play a vital role in optimizing waste collection. However, the methods for determin- AQ1 ing them are frequently omitted. Another parameter that has a great influence on waste collection is the time window. Here, the impact of time windows and travel times on the capacitated waste collection problem with time windows solution was assessed for collecting three waste types. Surprisingly, travel times were found to have minimal influence on route optimization, while time windows significantly affected the algorithm’s ability to identify the most efficient collection route. Addressing AQ2 these considerations is crucial for practical application and improving the performance of waste collection algorithms in real-world contexts.

2024Conference paper

Restricted access

Optimised model microcapsules of Arabic gum and gelatin a for functional cosmetic applications: From formulation to scale-up using a mesostructured reactor

Publication . Kessler, Júlia C.; Martins, Isabel M.; Manrique, Yaidelin A.; Lopes, José Carlos B.; Rodrigues, Alírio; Barreiro, M.F.; Dias, Madalena M.

Microcapsules were developed using Arabic gum and gelatin A through complex coacervation, employing both batch and continuous production methods. Ingredients were chosen to encapsulate diverse hydrophobic core materials with functional properties tailored for cosmetic applications, such as those found in commercial hydrating creams, aiming to enhance their performance through microencapsulation. The formulation was optimised by systematically adjusting key parameters to balance the electrostatic and structural behaviour of the polymers, ensuring ideal encapsulation conditions. The optimised batch formulation (3.5:1 vol-to-volume ratio of core material to emulsifier, stirring at 9500 rpm for 2 min, and 10 % crosslinker concentration) resulted in spherical, multinuclear microcapsules with an average size of circa 60 μm, maintaining structural stability over 45 days. Encapsulation efficiency, defined as the percentage of core material successfully enclosed within the microcapsules relative to the initial amount used, reached up to 89 %. Transitioning to a continuous production method using the NETmix reactor further improved performance, achieving an encapsulation efficiency of 98 %. This was accomplished by performing the emulsification and polymer complexation steps under controlled Reynolds numbers of approximately 358 and 559, sustained over 2 and 4 minutes, respectively.

2025Journal article

Open access