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Chondroitin sulfate (CS), a glycosaminoglycan, supports health through various physiological functions, including tissue protection, bone growth, and skin aging prevention. It also contributes to anticoagulant or anti-inflammatory processes, with its primary clinical use being osteoarthritis treatment. This study presents the results of the valorization of lipids and CS, both extracted from salmon co-products through enzymatic processes. The polar lipids, naturally rich in long-chain fatty acids (docosahexaenoic acid DHA C22:6 n-3 and eicosapentaenoic acid EPA C20:5 n-3), and the CS, primarily located in the nasal cartilage, were separated and concentrated before being characterized using various techniques to determine functional and lipid composition. These compounds were then used to formulate liposomes of 63 to 95 nm in size composed of 19.38% of DHA and 7.44% of EPA and encapsulating CS extract with a Δdi-4S/Δdi-6S ratio of 0.53 at 2 weight masses (10–30 kDa and >30 kDa) or CS standard all at two different concentrations. Liposomes were tested on human chondrocytes in inflamed conditions. Thus, compatibility tests, the expression of various inflammation markers at transcriptional and molecular levels, nitrites, and the amount of collagenase produced were analyzed. The results showed that CS, in synergy with the liposomes, played a positive role in combating chondrocyte inflammation even at a low concentration. [ABSTRACT FROM AUTHOR]

To meet the expectations of European consumers, who prioritize agro-environmental factors and local resources, the substitution of fats (palm, coconut, shea) and achieving a balanced fatty acid profile in spreadable fats are gaining more attention. The crystallization at 4 °C of a lipid blend composed of rapeseed oil, anhydrous dairy fats, and emulsifiers was studied using a multi-scale approach (DSC and X-ray diffraction techniques) to understand the emergence of polymorphic structures. Although the addition of PUFA from rapeseed oil reduces the atherogenicity and thrombogenicity indices in the blend, controlling the cooling kinetics influences the shapes (needles and spherulites) and sizes of the crystalline structures (small crystals form at a cooling rate of 1 °C min−1, while larger crystals form at higher rates of 5 and 10 °C min−1). The crystallization behavior revealed differences in polymorphic forms at 4 °C in the blend, with a transition to different forms occurring more rapidly compared to dairy fat (stop-and-return method). The study shows crystalline coexistence (α, β′, and β) in a 2L lamellar structure, with the β′ form being predominant. This structure is ideal for formulating a spreadable product, offering good spreadability (SFC < 32% at 10 °C), mouthfeel, and nutritional benefits compared to butter. [ABSTRACT FROM AUTHOR]

Nanoliposomes are nano-sized vesicles that can be used as drug delivery carriers with the ability to encapsulate both hydrophobic and hydrophilic compounds. Moreover, their lipid compositions facilitate their internalization by cells. However, the interaction between nanoliposomes and the membrane barrier of the human body is not well-known. If cellular tests and animal testing offer a solution, their lack of physiological relevance and ethical concerns make them unsuitable to properly mimic human body complexity. Microfluidics, which allows the environment of the human body to be imitated in a controlled way, can fulfil this role. However, existing models are missing the presence of something that would mimic a basal membrane, often consisting of a simple cell layer on a polymer membrane. In this study, we investigated the diffusion of nanoliposomes in a microfluidic system and found the optimal parameters to maximize their diffusion. Then, we incorporated a custom made GelMA with a controlled degree of substitution and studied the passage of fluorescently labeled nanoliposomes through this barrier. Our results show that highly substituted GelMA was more porous than lower substitution GelMA. Overall, our work lays the foundation for the incorporation of a hydrogel mimicking a basal membrane on a drug delivery microfluidic platform.

There is a growing interest for complex in vitro environments that closely mimic the extracellular matrix and allow cells to grow in microenvironments that are closer to the one in vivo. Protein-based matrices and especially hydrogels can answer this need, thanks to their similarity with the cell microenvironment and their ease of customization. In this study, an experimental design was conducted to study the influence of synthesis parameters on the physical properties of gelatin methacryloyl (GelMA). Temperature, ratio of methacrylic anhydride over gelatin, rate of addition, and stirring speed of the reaction were studied using a Doehlert matrix. Their impact on the following parameters was analyzed: degree of substitution, mass swelling ratio, storage modulus (log(G')), and compression modulus. This study highlights that the most impactful parameter was the ratio of methacrylic anhydride over gelatin. Although, temperature affected the degree of substitution, and methacrylic anhydride addition flow rate impacted the gel's physical properties, namely, its storage modulus and compression modulus. Moreover, this experimental design proposed a theoretical model that described the variation of GelMA's physical characteristics as a function of synthesis conditions.