Synthesis of yolk–shell NaA@HMSNs nanoparticles for bifunctional Cd2+ adsorption and curcumin delivery

An RF spacer creates a void between NaA and a mesoporous silica shell. • Shell thickness tunes curcumin loading in yolk–shell NaA@HMSNs. • NaA@HMSN-2 loads 124.0 mg/g curcumin and adsorbs Cd 2+ in vitro. • Curcumin release and Cd 2+ adsorption occur in the same buffer system. • HepG2 viability remains above 90% up to 64 μg/mL after 48 h. Cadmium contamination is an environmental and health concern. Here, a yolk–shell composite was constructed using sodium A-type zeolite (NaA) as the microporous yolk and a hollow mesoporous silica nanoparticle (HMSN) layer as the separated shell. Removal of a resorcinol–formaldehyde spacer generated an internal void, and three shell thicknesses were prepared. The NaA component provided Cd 2+ adsorption sites, whereas the amino-functionalized HMSN compartment was used for curcumin loading. N-NaA@HMSN-2, with an approximately 100 nm shell, loaded 124.0 mg/g curcumin. In buffer containing 100 mg/L Cd 2+ , Cur/N-NaA@HMSN-2 released 34.8% and 39.5% curcumin and adsorbed 73.8% and 67.8% Cd 2+ at pH 7.4 and 1.2, respectively. In HepG2 assays, all three NaA@HMSN carriers maintained more than 90% relative cell viability at concentrations up to 64 μg/mL after 48 h. These findings demonstrate coupled Cd 2+ adsorption and curcumin release under in vitro conditions and support further evaluation of this bifunctional material platform. Download: Download high-res image (96KB) Download: Download full-size image