Self-assembly behaviors of thermal- and pH- sensitive magnetic nanocarriers for stimuli-triggered release

Abstract

In the present work, we prepare thermo- and pH-sensitive polymer-based nanoparticles incorporating with magnetic iron oxide as the remote-controlled, stimuli-response nanocarriers. Well-defined, dual functional tri-block copolymer poly[(acrylic acid)-block-(N-isopropylacrylamide)-block-(acrylic acid)], was synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization with S,S′-bis(α,α′-dimethyl-α″-acetic acid)trithiocarbonate (CMP) as a chain transfer agent (CTA). With the aid of using 3-aminopropyltriethoxysilane, the surface-modified iron oxides, Fe3O4-NH2, was then attached on the surface of self-assembled tri-block copolymer micelles via 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinamide (EDC/NHS) crosslinking method in order to furnish not only the magnetic resources for remote control but also the structure maintenance for spherical morphology of our nanocarriers. The nanocarrier was characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet–visible (UV/Vis) spectral analysis. Rhodamine 6G (R6G), as the modeling drugs, was encapsulated into the magnetic nanocarriers by a simple swelling method for fluorescence-labeling and controlled release monitoring. Biocompatibility of the nanocarriers was studied via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed that neither the pristine nanocarrier nor the R6G-loaded nanocarriers were cytotoxic to the normal fibroblast cells (L-929 cells). The in vitro stimuli-triggered release measurement showed that the intelligent nanocarriers were highly sensitive to the change of pH value and temperature rising by the high-frequency magnetic field (HFMF) treatment, which provided the significant potential to apply this technology to biomedical therapy by stimuli-responsive controlled release.

Magnetically polymeric nanocarriers for targeting delivery of curcumin and hyperthermia treatments toward cancer cells

“…As aforementioned, the process included the self‐assembling of ABA tri‐block copolymer, poly(AA‐ b ‐NIPAAm‐ b ‐AA) with thermo‐ and pH‐induced method. Surface‐modified magnetic iron oxide nanoparticles (Fe 3 O 4 ‐NH 2 , MNPs) were successfully covalent‐bonded on the surface of self‐assembled polymeric nanogel, denoted as SAMN to provide not only the magnetic properties but also the stability of spherical structures . Furthermore, FA was grafted onto the magnetic nanocarriers, named as FA‐SAMN, for anti‐cancer targeting effect.…”

“…The size and morphology of magnetically polymeric nanocarriers with and without curcumin loading were determined by TEM imaging. Thermo‐ and pH‐triggered self‐assembly and magnetic iron oxide induced morphology‐fixing of poly(AA‐ b ‐NIPAAm‐ b ‐AA) were discussed in our previous work . Figure exhibits the images of SAMN, FA‐SAMN, and Cur‐FA‐SAMN.…”

“…Fe 3 O 4 ‐NH 2 was covalently bonded on the surface of self‐assembled A 100 N 150 , by EDC/NHS crosslinking method as described . A 100 N 150 (0.25 g) was dissolved in 50 mL H 2 O, and the pH value was adjusted to 4.5 with the diluted NaOH solution.…”

“…The objective of our present study is to provide a biocompatible, remote‐controllable, and anti‐cancer drug encapsulated, polymeric nanocarrier with thermo‐sensitivity and tumor‐solid selectivity as shown in Figure . Well‐defined, dual functional tri‐block copolymer‐based, magnetic nanocarriers were synthesized as our previous work . After curcumin‐loading and FA‐grafting to the magnetic nanocarriers, the smart nanocarriers were monitored and charactered its therapeutic behaviors via in vitro release test, MTT assay, fluorescence microscopy, and apoptosis study.…”

Dual-Responsive pH and Temperature Sensitive Nanoparticles Based on Methacrylic Acid and Di(ethylene glycol) Methyl Ether Methacrylate for the Triggered Release of Drugs

“…A similar block copolymer was also used to coat iron oxide nanoparticles. PNIPAAm acted here as a barrier and prevented Dox release above the LCST . Replacing the block copolymer by a statistical PNIPAAm‐PAA copolymer led in contrast to a fast release of the drug at low pH value .…”