Pectin-based magnetic molecularly imprinted polymer cross-linked via the Betti reaction and decorated by silver NPs (FeO@MIP/Ag): A safe and potential antibacterial nano-carrier for highly sustained release of tetracycline.

Designing a novel bio-platform as a nano-carrier with a significantly sustained drug release feature is a reliable and promising strategy for preventing the long-term dangers posed by bacterial infections. This route is favorable for various biomedical aspects, promoting the effectiveness of antibiotics in preventing bacterial growth sustainably. The purpose of this research is to synthesize a bio-based core-shell magnetic molecularly imprinted polymer (MIP) nano-carrier (FeO@MIP) through the Betti multi-component reaction (MCR) between dialdehyde pectin (DAP), β-naphthol, ethylenediamine (ETDA) (as cross-linking agent), and amine-functionalized FeO (as core). In the next step, silver nanoparticles (Ag NPs) were loaded at the cross-linked sites generated by the Betti reaction (FeO@MIP/Ag) to increase the antibacterial properties of the bio-based nano-carrier. Based on the achieved results from Langmuir adsorption isotherms, the imprinting factor was calculated (IF = 2.03). Besides, the binding kinetics of TCL implied the formation of specific recognition sites in the bio-based polymer matrix. The FeO@MIP/Ag nano-carriers were loaded with a substantial content of tetracycline (TCL) via the dispersion of the nano-carriers in an aqueous TCL solution. The release profile under pH 7.4 (simulated physiological conditions), showed a prolonged and sustained release over 120 h. The cytotoxicity of FeO@MIP/Ag NPs was deliberated toward Human skin fibroblast (HFF-1) cells via an in-vitro MTT assay, which displayed great cytocompatibility. Additionally, the antibacterial efficiency was evaluated for the bio-based FeO@MIP/Ag-loaded TCL against both S. aureus and E. coli with the minimum inhibitory concentration (MIC) values of 49 and 97.5 μg.mL, respectively.