An amphiphilic block copolymer conjugated with carborane and a NIR fluorescent probe for potential imaging-guided BNCT therapy

Abstract

A carborane-containing triblock copolymer conjugated with a near infrared (NIR) fluorescence probe has been synthesized via reversible addition fragmentation chain transfer (RAFT), ring open polymerization (ROP), and conjugations of a cyanine NIR dye. Reactions were traced by means of 1 H-NMR, GPC and FT-IR. The NIR amphiphilic copolymer with polycaprolactone and polycarborane as hydrophobic segments and poly(ethylene glycol)methyl ether methacrylate as the hydrophilic segment could self-assemble into micelles in aqueous solution, and was characterized by means of DLS and TEM. In the copolymer, carborane works as a boron neutron capture therapy (BNCT) agent while the aminocyanine (Cy) dye works as a NIR bioimaging agent, and the nanoparticles of the copolymers are a potential theranostic BNCT system for cancer therapy, which was supported by MTT experiments and in vitro fluorescence microscopy studies.Scheme 1 Internalization of the carborane-containing NIR polymeric nanoparticles followed by imaging guided BNCT therapy. † Electronic supplementary information (ESI) available. See

Recent Advances in Polyesters for Biomedical Imaging

“…The small penetration depth limits the use of optical imaging in the clinic, but the technique remains effective for applications like prostate, eye, and skin diagnostics and treatments . In this section, we highlight recent advances that combine fluorescent agents with polyesters in order to improve physical properties and overcome the shortcomings that arise from the use of free fluorescent dyes ( i.e., self‐quenching, low quantum yield, very short t 1/2 resulting from ultrasmall size (i.e., 1–2 nm), and rapid renal clearance) …”

“…In 2016, Ruan et al synthesized an amphiphilic block copolymer and conjugated a NIR fluorescent probe and carborane for potential imaging‐guided boron neutron capture therapy (BNCT) ( Figure ) . The amphiphilic carborane (i.e., the BNCT agent) was synthesized by RAFT polymerization of a carborane vinyl monomer and OEGMA with ROP of ε‐caprolactone.…”

“…Synthesis of the designed NIR amphiphilic copolymer via RAFT and ring opening polymerization. Reproduced with permission . Copyright 2016, the Royal Society of Chemistry.…”

“…In vitro fluorescence images of HepG2 cells cultured with Cy‐micelle NPs for 24 h. Reproduced with permission . Copyright 2016, the Royal Society of Chemistry.…”

Sharp‐pH‐Sensitive Amphiphilic Polypeptide Micelles with Adjustable Triggered pHs by Salts via the Hofmeister Effect

“…The designed polypeptide was synthesized via reversible addition fragmentation chain transfer (RAFT) and ring opening polymerization. Oligo poly(ethylene glycol) methyl ether acrylate (OEGMA) was chosen to be hydrophilic segment and tertiary amine contained polyaspartic acid as pH‐sensitive segment . Structure of the polymer was determined by means of NMR, Fourier transform infrared (FTIR), and gel permeation chromatography (GPC) measurements.…”