Sonia Andreia Oliveira Santos

Protein-based nanoparticles (NPs) are attracting increasing attention as sustainable platforms for advanced biomedical applications. However, achieving high encapsulation efficiencies without compromising nanoparticle stability and biocompatibility remains a key challenge for these bio-based delivery systems. In this context, bovine serum albumin (BSA) NPs crosslinked with genipin were developed as green and biocompatible nanocarriers with tunable physicochemical properties. The synthesis conditions were systematically optimized by varying reaction time, temperature, and the BSA:genipin ratio, with 24 h at room temperature and a 10:1 ratio yielding the most suitable NPs in terms of formation and colloidal stability. The optimized BSA NPs were then used to encapsulate sertraline and 5-fluorouracil, achieving encapsulation efficiencies of 82% and 40%, respectively. These results highlight the ability of this nanoplatform to incorporate bioactive compounds with distinct physicochemical characteristics, with the sertraline-loaded NPs showing particularly high loading efficiency for an albumin-based system. In vitro assays performed on normal prostate epithelial cells (PNT-2) and prostate cancer cells (22Rv1) showed that the BSA NPs modulated drug-induced cytotoxicity relative to free drugs, indicating a formulation-dependent biological response. These findings highlight the potential of genipin-crosslinked BSA NPs as a versatile and sustainable platform for drug delivery in cancer therapy.

The sensory perception of wine arises from dynamic interactions processed through two complementary pathways: orthonasal, via inhalation through the nasal cavity, and retronasal, occurring during consumption as compounds are released in the oral cavity and integrated with taste and tactile sensations. Although closures are known to affect oxidative–reductive balance during bottle storage, their impact on orthonasal and retronasal perception remains largely unexplored. To address this gap, a blend red wine from Burgenland, Austria, sealed with Natural Cork, Microagglomerated cork, and Screw Cap closures, was evaluated after 30 months of in-bottle storage. Analyses of physicochemical parameters and phenolic and volatile composition were combined with oxireduction sensory evaluation by a trained panel. Wine sealed with Natural Cork presented a more balanced and complex aroma profile, while wine sealed with a Screw Cap promoted reductive defaults associated with sulfur compounds. Wine sealed with Microagglomerated cork exhibited an intermediate behavior, with phenolic composition positioned between that with Natural Cork and a Screw Cap, and volatile profile showing, with the exception of sulfur compounds, a greater similarity to that with a Screw Cap. Notably, ortho- and retronasal oxireductive scores co-varied, driven by multiple volatile families, and are aligned with oxidation and/or reduction volatile marker content. These findings highlight the role of closure type in modulating both chemical composition and sensory perception, demonstrating that wine–closure pairing can be strategically used to guide the evolution of a wine’s identity during medium-term storage.

Lignins isolated from the straw of six rye (Secale cereale) varieties (Cl 98, Slapske, Zidlochovicke Panis, Ceske Normalni, Bates, and SU Stakkato) were comprehensively characterized by advanced analytical techniques to assess their structural features and valorization potential. Rye straws contained ∼15% of lignin, which was primarily constituted by guaiacyl (∼52–61%) and syringyl (∼35–45%) units, with minor amounts of p-hydroxyphenyl units (∼3%). The lignin backbone was enriched in β–O–4′ alkyl–aryl ether linkages (77–79%), followed by β–5′ (10–12%) and β–β′ (4–6%). All the lignins from the rye straws were enriched in tricin, with the Cl 98 variety having the highest content, reaching up to 26.2 g/kg straw. Since tricin is incorporated exclusively through 4′–O–β ether linkages, an environmentally benign deep eutectic solvent (DES, choline chloride/lactic acid, 1:10), which is known to efficiently cleave such bonds, was evaluated for its selective release. DES treatment of Cl 98 straw yielded 1.92 mg of free tricin/g straw, confirming the effective cleavage of β–O–4 linkages. This study highlights rye straw lignin as a tricin-enriched, renewable biopolymer, emphasizing its potential as a sustainable source for high-value tricin recovery and supporting the valorization of cereal crop residues within lignocellulosic biorefineries.

Background: Centella asiatica (L.) extract (ECA) has demonstrated immunostimulatory effects, with macrophages playing a key role in immune regulation. However, a significant proportion of bioactive compounds derived from natural sources exhibit poor aqueous solubility and may pose toxicity concerns, hindering their absorption and reducing their bioavailability. To address these limitations, nanotechnology-based drug delivery approaches have been explored, including the use of chitosan, a biocompatible polymer, as a carrier material. Methods: Centella asiatica extract-loaded chitosan nanoparticles (NECA) were developed and evaluated in this study to investigate their physicochemical properties and immunostimulatory activity. The nanoparticles were formulated using the ionic gelation technique, followed by freeze-drying, with different concentrations of ECA and sodium tripolyphosphate as the crosslinking agents. Comprehensive characterization was conducted, including particle size analysis, morphological observation, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Results: The resulting NECA particles ranged in size from 136.4 to 451.6 nm, with encapsulation efficiencies of 79.47% to 89.27%. XRD analysis indicated a transformation of the material from crystalline to predominantly amorphous, which may enhance solubility. The immunostimulatory activity was assessed in Balb/c mice using the carbon clearance assay. Administration of NECA at doses of 100 and 200 mg/kg significantly increased macrophage phagocytic activity and resulted in higher lymph and liver indices compared with the control group ( p < 0.05). Conclusion: These results demonstrate that NECA can enhance macrophage-mediated immune responses and may serve as a promising nanoparticle-based immunostimulant delivery system.

The invasive brown macroalga Rugulopteryx okamurae has rapidly expanded across the Mediterranean–Atlantic region, generating severe ecological impacts. Nevertheless, the considerable amount of biomass available creates opportunities for valorisation within circular bioeconomy frameworks. This study provides an integrated characterization of the chemical profile and bioactivities of freshly collected floating biomass of R. okamurae from southern Portugal. Proximate composition was determined, and lipophilic (hexane) and hydrophilic (water) extracts were analyzed by GC–MS and spectrophotometric methods. Antioxidant activity was assessed using complementary radical-scavenging, reducing power, and metal-chelation assays, and enzyme inhibition was evaluated against targets associated with neurodegenerative, metabolic, and dermatological disorders. The lipophilic fraction was dominated by long-chain alkanes (≈101 mg/g extract) and sterols, particularly fucosterol (≈43 mg/g extract), but exhibited low radical-scavenging capacity (no EC₅₀ reached in DPPH or ABTS assays), and no relevant enzyme inhibition. In contrast, the water extract contained measurable phlorotannins (6.61 mg PGE/g extract) and showed moderate antioxidant (ABTS: EC₅₀ = 5.17 mg/mL; FRAP: EC₅₀ = 0.78 mg/mL) and enzyme inhibition activities (BChE: IC₅₀ = 5.17 mg/mL; tyrosinase: IC₅₀ = 0.78 mg/mL). Compared with previous studies on R. okamurae, this work applies a systematic fractionation of biomass from southern Portugal into polar and non-polar fractions and, for the first time, correlates the resulting detailed chemical profiles with multiple bioactivities. This approach revealed a clear functional differentiation between fractions, with bioactivity being mainly associated with polar metabolites. Overall, these findings highlight the value of structured extraction strategies for biomass valorisation and support the sustainable management of R. okamurae.

Recognizing the importance of antioxidants in protecting the body against the damaging effects of free radicals and considering the limited information available in the literature regarding the stability of these molecules and the formation of oxidation products, this study aimed to evaluate the effect of oxidation on the degradation of selected phenolic compounds and its impact on their antioxidant capacity. Ellagic acid, chlorogenic acid, and protocatechuic acid were exposed to reactive species formed through solar radiation, the ascorbic acid/Cu2+ reaction, or the Fenton reaction. The resulting oxidation products were identified by ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC–MSn), and the antioxidant/pro-oxidant activity was assessed. Ellagic acid was degraded only after exposure to solar radiation, which could be related to its high structural stability or limited solubility, and no oxidation products were detected. Nine oxidation products of chlorogenic acid and one of protocatechuic acid were identified. Chlorogenic acid showed lower stability under the tested oxidation conditions. Although this phenolic compound demonstrated higher levels of degradation, the resulting oxidation products generally retained greater antioxidant activity than those formed from protocatechuic acid oxidation. Based on the obtained results, these phenolic compounds showed promising potential, confirming the relative stability of their antioxidant properties under the three oxidation processes tested. These findings support their potential use in cosmetic formulations for topical application to protect the skin from oxidative damage caused by solar radiation, as well as in food supplements aimed at combating reactive oxygen species formed in the body.

Oleoresin from Pinus spp. consists of turpentine and rosin, whose compositional variability demands reliable analytical methods for quality control and industrial processing. This study provides three rapid methods for qualitative and quantitative analyses of oleoresin, turpentine, and rosin by gas chromatography coupled with mass spectrometry (GC-MS) using a single DB-1 column and matrix-specific temperature programs. Oleoresin and rosin were first derivatized using diazomethane, and compounds were identified by elution order, fragmentation patterns, and reference mass spectra. Quantification employed external calibration with α-pinene and abietic acid as representative standards. In P. pinaster oleoresin, the main terpenic compounds were α-pinene (6.67 ± 1.08%), longifolene (2.45 ± 0.20%), and β-caryophyllene (1.71 ± 0.15%), while levopimaric (33.75 ± 2.70%), neoabietic (13.97 ± 1.70%), and abietic acids (12.60 ± 2.90%) predominated among resin acids. P. elliottii rosin contained mainly abietic (45.99 ± 4.82%), isopimaric (16.95 ± 2.55%), and palustric acids (9.74 ± 1.20%), and its turpentine comprised mainly α-pinene (34.16 ± 2.45%) and β-pinene (30.03 ± 1.20%). This unified GC–MS framework, supported by representative calibration standards, enables identification of >95% of compounds in pine matrices. Furthermore, once compound identification has been established through GC-MS, GC coupled with flame ionization detector (GC-FID) can be employed for routine quantitative analysis.