Synthesis of surface functionalized hollow microporous organic capsules for doxorubicin delivery to cancer cells

Abstract

Functionalized hypercrosslinked polymers have presented potential applications in various fields and are highly potent in bio-medical applications. Irrespective of random morphology, hypercrosslinked polymers with a spherical and hollow capsular shape are worthy of fabrication and functionalization. Based on the appealing performance of polymeric capsules, herein we report the synthesis of folate-functionalized biocompatible hollow capsules that have a reasonable potential for the delivery of anticancer drugs specifically to the cancer cells. The pyrene units are incorporated into these capsules to further enhance their scope for imaging applications. To improve the targeting efficiency, the folic acid was conjugated to the surface of hollow microporous organic capsules (HMOCs-FA) via a facile strategy using SiO₂ nanoparticles as templates and the covalent attachment of FA on the surface of capsules. These microporous organic capsules exhibit a high surface area of up to 700 m² g⁻¹ and a maximum encapsulation drug efficiency of up to 86%. Moreover, the HMOCs-FA are highly biocompatible and are internalized by MCF-7 and MDA-MB-231 cell lines via folate receptor mediated endocytosis.