A new pH/redox/light stimuli-responsive magnetic molecularly imprinted polymer based on β-cyclodextrin for recognition and controlled release of andrographolide

Abstract

To improve the recognition ability and the controlled release of andrographolide (ADR), it is necessary to prepare a better intelligent drug delivery carrier. In this paper, the magnetic andrographolide imprinted polymer (ADR-MMIP) with pH/redox/light triple stimulus response was successfully prepared by reverse atom transfer radical polymerization (RATRP), where ADR was as the template, β-Cyclodextrin (β-CD) and 4-amino-4′-methacrylamide azobenzene (AMAB) as the bi-functional monomers, and both of N, N′-bis (acryloyl) cystamine (BAC) and ethylene glycol dimethacrylate (EGDMA) as cross-linkers. A series of adsorption experiments indicated that ADR-MMIP had excellent adsorption and selectivity capacities with the maximum adsorption capacity 41.43 mg g−1 and the factors α 4.256 and β 1.940 for the selectivity and relative selectivity, respectively. The adsorption mechanism of ADR-MMIP was investigated the multiphase adsorption with the chemical action on heterogeneous material surface by the linear fitting with the isothermal and kinetic adsorption models, and the in-vitro ADR release showed ADR-MMIP was sensitive to the triple-stimuli of pH/redox/light with the maximum cumulative drug release rate 91.53% when the above three conditions were applied concurrently. The above information demonstrated the ADR-MMIP should be of great application potential in the ADR extraction and isolation from mixture and the intelligent drug delivery system.