Thermosensitive PMMA core/oligo(ethylene glycol)‐based shell microgels as drug carriers in detoxification treatment

The core‐shell structured polymer microgels were synthesized by coating the hydrophobic poly(methyl methacrylate) (PMMA) sphere cores with hydrophilic nonlinear poly(ethylene glycol)‐based gel shell layer. The uniqueness of these core‐shell microgels lies in the integration of the PMMA core microsphere with strong hydrophobicity and the novel oligo(ethylene glycol)‐based gel layer with well‐defined thermosensitivity for improving loading/release efficacy of two detoxification drugs (chlorpromazine and diltiazem). The hydrophilic shell is composed of hydrophilic copolymer of 2‐(2‐methoxyethoxy)ethyl methacrylate (MEO2MA) with oligo(ethylene glycol) methyl ether methacrylates (MEO5MA). It was found that the molar ratio of two shell monomersn(MEO2MA)/n(MEO5MA) of 1:6 was an ideal matching value for production of the P(MEO2MA)/P(MEO2MA‐co‐MEO5MA) core‐shell microgels with tunable volume phase transition temperature and excellent colloidal stability across the physiologically important temperature range. Moreover, chlorpromazine‐ and diltiazem‐loaded microgels can show an obvious thermosensitive release and in vitro sustained‐release characteristic up to 80 h.