Facile synthesis of self-assembled spherical and mesoporous dandelion capsules of ZnO: Efficient carrier for DNA and anti-cancer drugs

This work presents a new facile strategy to fabricate self-assembled spherical and mesoporous submicron-sized capsules, 'dandelions', of ZnO nanorods and nanoparticles. Self-assembled 'dandelion' capsules have been synthesized from Zn(Ac)₂ and Igepal CO-520, and the mechanistic approach for the growth of self-assembled ZnO capsules has been elucidated. Physical characteristics of the novel capsules responsible for biomedical applications have been studied through XRD, Raman spectroscopy, UV-Vis-NIR spectroscopy, XPS and EPR. The mechanical stability of the capsules has been characterized using high energy ultrasound with time in 10% PBS buffer. The biocompatibility of the capsules has been investigated with a cell-based study using normal lymphocyte and K562 cancer cells through MTT assay. The loading and release efficiency of the fluorescent molecules (Rhodamine 6G), anti-cancer drugs (doxorubicin hydrochloride, DOX), and deoxyribonucleic acid (DNA) have been investigated. All the results indicate the high potential of self-assembled ZnO 'dandelion' capsules in relevant applications, such as for sustained drug delivery with the formation of a {(ZnO)_n^δ+-(DOX)_m} complex and gene delivery with the formation of a {(ZnO)_n^δ+- (DNA)_m complex, in medical biotechnology. The fabrication of such self-assembled idiosyncratic capsules is very simple, feasible, and cost effective; moreover, it demonstrates improved performance in drug and gene delivery applications.