Astaxanthin (ASX) is a carotenoid of great interest due to its potential health benefits. However, its use in the food, feed, and pharmaceutical fields is limited due to low bioavailability, poor stability during thermochemical treatments, susceptibility to oxidation, and poor organoleptic characteristics. The aim of this work was to develop a method to stabilize astaxanthin extracted from the microalgae Haematococcus pluvialis (H.p.) and to improve its nutritional and functional properties through nanoencapsulation. Nanoparticles (NPs) were produced by emulsification–solvent evaporation technique starting from H.p. oleoresin using whey proteins concentrate (WPC) as stabilizer. The efficiency of encapsulation was 96%. The particle size (Z-average) was in the range of 80–130 nm and the superficial charge (measured as zeta-potential) was negative (−20 to −30 mV). The stability of the NPs upon resuspension in water was assayed through a panel of stress tests, i.e., extreme pH, UV radiation, Fe³⁺ exposition, and heating at 65 °C, that always showed a superior performance of encapsulated ASX in comparison to oleoresin, even if NPs tended to precipitate at pH 3.5–5.5. Simulated gastroenteric digestion was conducted to study the release of ASX in physiological conditions, and showed a maximum bioaccessibility of 76%, with 75% ASX converted into the more bioavailable free form. The collected data suggest that NPs might have possible future applications as supplements for human and animal diets.

Radiation-induced fibrosis is a serious long-lasting side effect of radiation therapy. Central to this condition is the role of macrophages that, activated by radiation-induced reactive oxygen species and tissue cell damage, produce pro-inflammatory cytokines, such as transforming growth factor beta (TGF$\beta$). This, in turn, recruits fibroblasts at the site of the lesion that initiates fibrosis. We investigated whether astaxanthin, an antioxidant molecule extracted from marine and freshwater organisms, could help control macrophage activation. To this purpose, we encapsulated food-grade astaxanthin from Haematococcus pluvialis into micrometer-sized whey protein particles to specifically target macrophages that can uptake material within this size range by phagocytosis. The data show that astaxanthin-loaded microparticles are resistant to radiation, are well-tolerated by J774A.1 macrophages, induce in these cells a significant reduction of intracellular reactive oxygen species and inhibit the release of active TGF$\beta$ as evaluated in a bioassay with transformed MFB-F11 fibroblasts. Micro-encapsulation of bioactive molecules is a promising strategy to specifically target phagocytic cells and modulate their own functions.

Radiation-induced fibrosis (RIF) is a serious, yet incurable, complication of external beam radiation therapy for the treatment of cancer. Macrophages are key cellular actors in RIF because of their ability to produce reactive oxidants, such as reactive oxygen species (ROS) and inflammatory cytokines that, in turn, are the drivers of pro-fibrotic pathways. In a previous work, we showed that phagocytosis could be exploited to deliver the potent natural antioxidant astaxanthin specifically to macrophages. For this purpose, astaxanthin encapsulated into µm-sized protein particles could specifically target macrophages that can uptake the particles by phagocytosis. In these cells, astaxanthin microparticles significantly reduced intracellular ROS levels and the secretion of bioactive TGFβ and increased cell survival after radiation treatments. Here we show that pentoxifylline, a drug currently used for the treatment of muscle pain resulting from peripheral artery disease, amplifies the effects of astaxanthin microparticles on J774A.1 macrophages. Combination treatments with pentoxifylline and encapsulated astaxanthin might reduce the risk of RIF in cancer patients.

Protein-based nanoparticles, composed of water-soluble proteins, represent a promising platform for reducing side effects during drug delivery. They enhance the solubility, stability, and bioavailability of hydrophobic therapeutic agents while maintaining high biocompatibility and biodegradability in vivo. These nanoparticles are nontoxic and capable of encapsulating both hydrophilic and hydrophobic drugs, making them highly versatile. In this study, we explored the potential of whey proteins derived from bovine milk to engineer nanoparticles for efficient drug delivery. Whey proteins, traditionally regarded as waste byproducts of cheese production, have recently gained attention for their potential in drug encapsulation, thanks to their excellent biocompatibility and biodegradability. We synthesized two types of nanoparticles based on a previously engineered whey protein, named Matrix and Core–shell. Following their characterization, we investigated their effects on cellular uptake, cytotoxicity, and cell proliferation, using a curcumin extract with known anticancer properties as a model drug. The study demonstrated that whey protein nanoparticles are highly efficient in drug encapsulation, with both types of nanoparticles exhibiting efficient cellular uptake and enhanced cytotoxicity at higher concentrations in tumor cells compared to healthy cells. These results confirm the potential of whey protein nanoparticles as a platform for targeted drug delivery, particularly in cancer therapy. Overall, this research underscores the promise of whey protein-based nanoparticles as an innovative, sustainable, and effective approach to advancing targeted cancer therapy.

Rhamnolipids are a class of glycolipids known for their surface and emulsifying activity. These molecules, produced by a few Gram-negative genera, mostly Pseudomonas, offer natural alternatives to synthetic surfactants in different industrial fields. This study examines the emulsifying and encapsulation performance of Rhamnolipids derived from the marine Antarctic bacterium Pseudomonas gessardii M15, comparing its emulsification ability and stability with those of commercial surfactants, Sodium dodecyl sulfate (SDS) and sucrose esters (SE), under extreme conditions of temperature and pH. The Rhamolipids were used to encapsulate Coenzyme Q10 with Arabic gum as the carrier matrix. Rhamnolipids exhibited surface and emulsifying activity comparable to that of SDS and superior to SE at neutral and basic pH levels. Their performance declined under acidic conditions, whereas exposure to 90 °C had no significant effects. The encapsulation efficiency of Coenzyme Q10 was significantly higher in the case of Rhamnolipids, with a percentage of encapsulated compound of 99.6 ± 0.2%, compared to the 38.2 ± 7.1% found when SDS was used. Rhamnolipids extracted from Pseudomonas gessardii M15 exhibit strong potential as a natural surfactant, particularly in formulations that require thermal stability and effective encapsulation. These findings support its use as a sustainable alternative to synthetic agents in diverse industrial settings.