Ultrasonic complexation with Lycium barbarum polysaccharide significantly enhances the aqueous solubility and bioavailability of curcumin

Curcumin is a natural bioactive compound with a wide range of established health benefits. However, its practical applications are severely limited due to extremely poor aqueous solubility, which directly leads to low bioavailability. While polysaccharides like Lycium barbarum polysaccharide (LBP) can partially improve curcumin solubility, their solubilization efficiency remains limited. To overcome this challenge, we implemented ultrasonication as an effective processing strategy to enhance LBP's capacity to promote curcumin dissolution. Our findings show that ultrasound-induced cavitation and related physico-chemical effects markedly improve LBP's solubilization performance. The ultrasonically-assisted curcumin-LBP complex (CL-U) was systematically optimized through response surface methodology (RSM), identifying ultrasonic power, duration, and temperature as critical parameters. Extensive characterization verified that ultrasonication is essential for producing spherical core-shell nanoparticles, achieving a 2.23-fold enhancement in drug loading efficiency along with superior colloidal stability. Additional evidence from FTIR spectroscopy and acid hydrolysis experiments confirmed that ultrasonication reinforces hydrogen bonding as the principal intermolecular interaction stabilizing the complex. Biologically, CL-U demonstrated rapid cellular uptake in 4T1 cells within one hour and showed substantially improved antioxidant performance in both DPPH and ABTS assays. These functional gains are directly linked to the ultrasound-mediated improvements in solubility, stability, and bioavailability. This research establishes ultrasonication as a crucial sonochemical approach for constructing advanced polysaccharide-based delivery systems, providing a viable pathway for curcumin utilization in functional foods and pharmaceutical products.