pH protective Y1 receptor ligand functionalized antiphagocytosis BPLP-WPU micelles for enhanced tumor imaging and therapy with prolonged survival time

Abstract

Nanoparticle-based tumor therapies are extensively studied; however, few are capable of improving patient survival time due to premature drug leakage, off target effects, and poor tissue penetration. Previously, we successfully synthesized a novel family of Y₁ receptor (Y₁R) ligand modified, photoluminescent BPLP nanobubbles and nanoparticles for targeted breast cancer ultrasound imaging; however, increased accumulation could also be observed in the liver, kidney, and spleen, suggesting significant interaction of the particles with macrophages in vivo. Herein, for the first time, we imparted antiphagocytosis capability to Y₁R ligand functionalized BPLP-WPU polymeric micelles through the incorporation of a CD47 human glycoprotein based self-peptide. Application of self-peptide modified, DOX loaded micelles in vivo resulted in a 100% survival rate and complete tumor necrosis over 100 days of treatment. In vivo imaging of SPION loaded, self-peptide modified micelles revealed effective targeting to the tumor site while analysis of iron content demonstrated reduced particle accumulation in the liver and kidney, demonstrating reduced macrophage interaction, as well as a 2-fold increase of particles in the tumor. As these results demonstrate, Y₁R ligand, self-peptide modified BPLP-WPU micelles are capable of target specific cancer treatment and imaging, making them ideal candidates to improve survival rate and tumor reduction clinically.

Keywords: Antiphagocytosis; BPLP-WPU; Tumor imaging and therapy; Y(1) receptor ligand; pH responsiveness.