Photo-responsive polymeric micelles and prodrugs: synthesis and characterization

Abstract

Bio-recognizable and photocleavable amphiphilic glycopolymers and prodrugs containing photodegradable linkers (i.e. 5-hydroxy-2-nitrobenzyl alcohol) as junction points between biorecognizable hydrophilic glucose (or maltose) and hydrophobic poly(a-azo-3-caprolactone)-grafted alkyne or drug chains were synthesized by combining ring-opening polymerization, nucleophilic substitution, and "click" post-functionalization with alkynyl-pyrene and 2-nitrobenzyl-functionalized indomethacin (IMC). The block-grafted glycocopolymers could self-assemble into spherical photoresponsive micelles with hydrodynamic sizes of <200 nm. Fluorescence emission measurements indicated the release of Nile red, a hydrophobic dye, encapsulated by the Glyco-ONB-P(aN 3 CL-galkyne) n micelles, in response to irradiation caused by micelle disruption. Light-triggered bursts were observed for IMC-loaded or -conjugated micelles during the first 5 h. Following light irradiation, the drug release rate of IMC-conjugated micelles was faster than that of IMC-loaded micelles. Selective lectin binding experiments confirmed that glycosylated Glyco-ONB-P(aN 3 CL-g-alkyne) n could be used in biorecognition applications. The nano-prodrug with and without UV irradiation was associated with negligible levels of toxicity at concentrations of less than 30 mg mL À1. The confocal microscopy and flow cytometry results indicated that the uptake of doxorubicin (DOX)-loaded micelles with UV irradiation by HeLa cells was faster than without UV irradiation. The DOX-loaded Gluco-ONB-P(aN 3 CL-g-PONBIMC) 10 micelles effectively inhibited HeLa cells' proliferation with a half-maximal inhibitory concentration of 8.8 mg mL À1.

Silicon Tetrapyrazinoporphyrazine Derivatives-Incorporated Carbohydrate-Based Block Copolymer Micelles for Photodynamic Therapy

“…The zeta potential was evaluated to investigate micellar stability of PM1 – 3 . In general, when the absolute value of the zeta potential of the micelle is equal or greater than 30 mV, the stability of micelle could be warranted by electrostatic repulsion. , The zeta potentials of PM1 , PM2 , and PM3 are −21.33, −40.99, and −45.64 mV, respectively, which indicate that the glucosyl groups of PM2 and PM3 could contribute their stability in the blood. Furthermore, to investigated that the space of the hydrophobic core of PMs encapsulate SiTPyzPz - THS , LC and LE were measured by UV–vis spectrometer, and Table S1 provides the LC and LE data of PM1 – 3 .…”

Dual Thermo- and Photo-Responsive Micelles Based on Azobenzene-Containing Random Copolymer

“…Stimuli-responsive micelles are the aggregates in solution which consist of a core formed by the hydrophobic blocks and a shell composed by hydrophilic blocks, featuring some special functional groups which can respond to various chemical and physical stimuli such as pH, temperature, light, ions and redox [ 1 , 2 , 3 , 4 , 5 , 6 ]. The potential applications of stimuli-responsive micelles in controlled release, drug delivery, biosensors, catalyst system, and nano-reactors [ 7 , 8 , 9 , 10 , 11 ] and are attributed to the polymeric micelles changes induced by the responsive moieties in morphology, diameter, polarity and structure under the external stimuli.…”