Molecularly imprinted submicronspheres for applications in a novel model biosensor-film

Two different molecularly imprinted polymers (MIP1 and MIP2) in the form of submicron-particles were obtained by radical polymerization, using acetonitrile as a solvent, methacrylic acid (MAA) as a functional monomer, a cross-linking agent (trimethylolpropane trimethacrylate (TRIM) for MIP1 and pentaerythritol triacrylate (PETRA) for MIP2) and phenylalanine aminoacid (Phe) as a template molecule. The extraction of Phe template from polymer submicron-particles by washing steps allowed the formation of free recognition sites for the selective rebinding of template molecule. Rebinding ability was evaluated in acetonitrile and in phosphate buffered saline by chromatographic methods and compared to that of corresponding control polymers. As MIP1 showed a superior specificity towards Phe rebinding as compared to MIP2, it was selected as a component of a poly(l-lactic acid) (PLLA) based model sensor-scaffold. Impedance measurements, carried out on PLLA films loaded with as-produced, extracted or rebound MIP1 submicron-particles demonstrated the possibility to build a scaffold capable of sensing the amount of rebound template. In the future, devices incorporating MIP submicron-particles able to rebind extracellular matrix or transmembrane proteins will be respectively used as structures promoting cell adhesion and proliferation and sensor-films monitoring cell colonization.