Photo/pH dual-responsive biocompatible poly(methacrylic acid)-based particles for triggered drug delivery

Rational design of hollow mesoporous titania nanoparticles loaded with curcumin for UV-controlled release and targeted drug delivery

Curcumin (Cur), appeared to provide huge potential in biomedical application. However, its therapeutic efficacy was greatly limited as the result of poor solubility and instability. To address these limitations, we create a new type of hollow mesoporous titania nanoparticle (HMTN) to encapsulate Cur. HMTN was decorated with a layer of hydrophilic polyethylenimine (PEI), which controlled the release rate of Cur inside the pore due to its dendritic structure. Combined with the folic acid (FA) mediated targeting effect, the potential multifunctional Cur loaded titania nanoparticle (Cur-FA-PEI-HMTN) showed excellent biocompatibility and bioavailability, as well as the UV-responsive drug release properties. The operating parameters to prepare hollow structure were studied and the Cur-FA-PEI-HMTN nanosystem had been fully characterized by Brunauer-Emmet-Teller, Fourier transform infrared spectroscopy, transmission electron microscope, thermal gravity analysis, differential thermal analysis, x-ray diffraction, dynamic light scattering and zeta potential. In addition, the hemolytic test, as well as CCK8, flow cytometry, Hoechst 33342 staining experiment, were carried out to confirm the low cytotoxity and high biocompatibility. The confocal microscopy analysis results also revealed the increasing uptake of Cur@FA-PEI-HMTN by MCF-7 cells. The synthesized nanoparticles displayed great potential as drug nanovehicles with high biocompatibility.

Synthesis of Photo- and pH Dual-Sensitive Amphiphilic Copolymer PEG43-b-P(AA76-co-NBA35-co-tBA9) and Its Micellization as Leakage-Free Drug Delivery System for UV-Triggered Intracellular Delivery of Doxorubicin

Novel photo- and pH dual-sensitive amphiphilic copolymers containing photolabile o-nitrobenzyl (NB) groups were designed via combination of ATRP, hydrolyzation, and simple esterification reaction and self-assembled into stimuli-regulated amphiphilic micelles in aqueous solution. On the basis of the optimization of the morphology and particle size of the micelles via modulating the number of the photocleavable o-nitrobenzyl acrylate (NBA) units, the unique ones assembled from PEG43-b-P(AA76-co-NBA35-co-tBA9) with an average hydrodynamic diameter (Dh) of 163 nm was selected as a potential drug delivery system (DDS) for UV-triggered delivery of doxorubicin (DOX). The micelles possessed a favorable drug-loading capacity (DLC) of 27.5%, with the hydrodynamic diameter of 213 nm after DOX-loading. Most importantly, the DOX-loaded PEG43-b-P(AA76-co-NBA35-co-tBA9) micelles exhibited a cumulative DOX release ratio of only 3.69% in the simulated physiological medium within 6 days without UV-irradiation, indicating their potential as leakage-free DDS. As in the acidic media mimicking the tumor microenvironment, a high cumulative DOX release ratio of 74.70% was achieved within 6 days after UV-irradiation for 20 min, showing a sustained release behavior. Under UV-irradiation, the photolabile o-nitrobenzyl moieties were cleaved off, the amphiphilic copolymer transformed into a water-soluble polymer, favoring the metabolism of drug carriers, and the micelles were demicellized to accelerate the drug release in a triggered or on-demand manner.