The aim of the present study is the development, physicochemical characterization, and in vitro cytotoxicity evaluation of both empty and quercetin-loaded HSPC (hydrogenated soy phosphatidylcholine) liposomes, GMO (glyceryl monooleate) liquid crystalline nanoparticles, and PHYT (phytantriol) liquid crystalline nanoparticles. Specifically, HSPC phospholipids were mixed with different non-ionic surfactant molecules (Tween 80 and/or Span 80) for liposomal formulations, whereas both GMO and PHYT lipids were mixed with Span 80 and Tween 80 as alternative stabilizers, as well as with Poloxamer P407 in different ratios for liquid crystalline formulations. Subsequently, their physicochemical properties, such as size, size distribution, and ζ-potential were assessed by the dynamic and electrophoretic light scattering (DLS/ELS) techniques in both aqueous and biological medium with serum proteins. The in vitro biological evaluation of the empty nanosystems was performed by using the MTT cell viability and proliferation assay. Finally, the entrapment efficiency of quercetin was calculated and the differences between the two different categories of lipidic nanoparticles were highlighted. According to the results, the incorporation of the non-ionic surfactants yields a successful stabilization and physicochemical stability of both liposomal and liquid crystalline nanoparticles. Moreover, in combination with an appropriate biosafety in vitro profile, increased encapsulation efficiency of quercetin was achieved. Overall, the addition of surfactants improved the nanosystem’s stealth properties. In conclusion, the results indicate that the physicochemical properties were strictly affected by the formulation parameters, such as the type of surfactant.

Co-encapsulation of hydrophilic and hydrophobic compounds within a single delivery system remains a significant challenge across various scientific and industrial fields. Towards this direction, an encapsulation strategy is proposed, enabling the simultaneous incorporation of both hydrophilic and hydrophobic biomolecules within a hydrogel matrix. Specifically, the cyanobacterial protein phycocyanin (hydrophilic), extracted and purified by dry Arthrospira maxima biomass, and curcumin (hydrophobic) bound to bovine serum albumin (BSA) were utilized. This approach facilitates the indirect entrapment of hydrophobic molecules within the hydrophilic hydrogel network. The structural and physicochemical properties of the resulting hydrogels were characterized using optical analysis, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Additionally, the antioxidant potential of the encapsulated biomolecules was evaluated to assess their functionality after the encapsulation. Furthermore, a cell viability assay confirmed the hydrogel’s biocompatibility and lack of toxicity, demonstrating its suitability as a multifunctional biomaterial for biomedical and pharmaceutical applications.