Responsively Aggregatable Sub-6 nm Nanochelators Induce Simultaneous Antiangiogenesis and Vascular Obstruction for Enhanced Tumor Vasculature Targeted Therapy

Abstract

Inhibiting the formation of new tumor blood vessels (so-called antiangiogenesis) and obstructing the established ones are two primary strategies in tumor vasculature targeted therapy. However, the therapeutic outcome of conventional methodologies relying on only one mechanism is rather limited. Herein, the first example of ultrasmall responsively aggregatable nanochelators that can intrinsically fulfill both antivasculature functions as well as high renal clearable efficiency is introduced. The nanochelators with sub-6 nm sizes exhibit not only systemic copper depletion activity for tumor antiangiogenesis but also, more surprisingly, the capability to transform from a "dispersed" state to an "aggregated" state to form large secondary particles in response to tumor microenvironment with elevated copper and phosphate levels for blood vessel obstruction. Compared to a benchmark antiangiogenic agent that can only inhibit the formation of tumor blood vessels, the nanochelators with unprecedented synergistic functions demonstrate significantly enhanced tumor inhibition activity in both breast cancer and colon cancer tumor models. Moreover, these ultrasmall nanochelators are noncytotoxic and renal clearable, ensuring superior biocompatibility. It is envisaged that the design of nanomaterials with ground-breaking properties and the synergistic antivasculature functions would offer a substantial conceptual advance for tumor vasculature targeted therapy and may provide vast opportunities for developing advanced nanomedicines.

Keywords: Ultrasmall nanochelators; antiangiogenesis; copper depletion; organosilica; vascular obstruction.