Thermo/pH Dual Responsive Mixed‐Shell Polymeric Micelles Based on the Complementary Multiple Hydrogen Bonds for Drug Delivery

Abstract

Thermo/pH dual responsive mixed-shell polymeric micelles based on multiple hydrogen bonding were prepared by self-assembly of diaminotriazine-terminated poly(ɛ-caprolactone) (DAT-PCL), uracil-terminated methoxy poly(ethylene glycol) (MPEG-U), and uracil-terminated poly(N-vinylcaprolactam) (PNVCL-U) at room temperature. PCL acted as the core and MPEG/PNVCL as the mixed shell. Increasing the temperature, PNVCL collapsed and enclosed the PCL core, while MPEG penetrated through the PNVCL shell, thereby leading to the formation of MPEG channels on the micelles surface. The low cytotoxicity of the mixed micelles was confirmed by an MTT assay against BGC-823 cells. Studies on the in vitro drug release showed that a much faster release rate was observed at pH 5.0 compared to physiological pH, owing to the dissociation of hydrogen bonds. Therefore, the mixed-shell polymeric micelles would be very promising candidates in drug delivery systems.

A Facile Strategy for Fabrication Lysozyme-Loaded Mesoporous Silica Nanotubes from Electrospun Silk Fibroin Nanofiber Templates

“…The equation of the cumulative drug release. Reference [44] is cited in the Supplementary Materials. Funding: This research was funded by the Natural Science Foundation of Shanxi Province, China, grant number 201801D121102" and "The APC was funded by the Natural Science Foundation of Shanxi Province, China".…”

Recent advances in aliphatic polyesters for drug delivery applications

“…PNVCL‐U has an LCST of 32°C; thus, in the physiological pH, the PNVCL will collapse onto the PCL core protecting the drug inside the core. When at intracellular pH, due to the breakage of the hydrogen bonds, the micelles will disassemble and the drug will be released …”

“…When at intracellular pH, due to the breakage of the hydrogen bonds, the micelles will disassemble and the drug will be released. 90 PEG-PCL-PNIPAAm star terpolymer synthesized by Chen and coworkers self-assembles into vesicles in aqueous media and is dually responsive to pH and reduction environments. Because of the cleavable behavior of the star terpolymer in the presence of DTT, the polymer vesicle will undergo gradual dissociation releasing the drug.…”

Aqueous-based electrospun P(NIPAAm-co-AAc)/RSF medicated fibrous mats for dual temperature- and pH-responsive drug controlled release

“…12 Due to its molecular structure contains temperature-sensitive amide group and pH-sensitive carboxyl group, the LCST of P(NIPAAm-co-AAc) can be adjusted depending to the change of composition, meanwhile, the copolymer has the characteristic of dual response of temperature and pH, which has a good application prospect in the eld of drug carriers. 13,14 Responsive drug carriers come in various forms, such as hydrogels, 15,16 microgels, 17 lms 18 and macro-nanobers. [19][20][21] The form of macro-nanobers have uniquely advantage because the features provide extremely large surface area and porosity, which enhance the sensitivity to external stimuli.…”