Structural characteristics, binding behaviors, and stability of ternary nanocomplexes of lecithin, polyvinylpyrrolidone, and curcumin

Abstract

Low stability and bioaccessibility are two unfavourable features that limit the application of many hydrophobic compounds. In this study, lecithin was complexed with polyvinylpyrrolidone K30 (PVPK30) to enhance the stability and bioaccessibility of curcumin via a precipitation-ultrasonication method. The curcumin-loaded nanocomplexes exhibited uniform sizes (∼120 nm), low polydispersity (∼0.22), and negative zeta potential (∼−45 mV). Curcumin was molecularly dispersed in lecithin-PVP complexes and exhibited an amorphous state. The curcumin-loaded nanocomplexes possess excellent dilution, thermal, and storage stability. More importantly, in vitro simulated gastrointestinal digestion experiment showed that the nanocomplexes could significantly improve the bioaccessibility of curcumin, reaching 105 times. Molecular dynamics simulation study revealed that lecithin and PVPK30 stabilized curcumin through hydrogen bonds, π-π interactions, and hydrophobic interactions. Our study provides a new way for curcumin and other hydrophobic compounds with excellent stability and bioaccessibility.