Sintesi di nanoparticelle polimeriche fluorescenti per imaging

The synthesis of PMMA-based nanoparticles (NPs) covalently labeled with a fluorescent dye is investigated for imaging applications such as cell uptake and biodistribution. Batch emulsion polymerization (BEP) and monomer-starved semi-batch emulsion polymerization (MSSEP) are adopted using SDS. Fluorescent properties are added to these NPs using Rhodamine-B (RhB) as a fluorescent dye covalently bonded to 2-hyroxyethyl-acrylate. The resulting HEMA-RhB monomer is copolymerized with MMA via BEP and MSSEP to synthesize fluorescent NPs. Subsequently, SDS is substituted with a biocompatible surfactant, Tween80, through ionic-exchange resins. ζ-potential measurements confirmed the complete surfactant exchange that leads to biocompatible fluorescent NPs with tunable size and narrow size distribution;The aim of the work is to synthesize biocompatible and surfactant free positively charged nanoparticles (NPs) based of poly(methyl methacrylate) (PMMA) covalently bonded with a fluorescent dye which make them suitable for theranostics application or delivery of negative compound such as siRNA. NPs were produced through emulsion polymerization carried out in batch (BEP) and monomer-starved semi-batch (MSSEP) condition using CTMAB or hema-choline (HEMA-Ch) as stabilizers and a positively charged initiator. To investigate the effects of HEMA-Ch, different particles diameter have been obtained using different stabilizer-to-monomer percentage weight ratios (CTMAB/MMA and HEMA-Ch/MMA), obtaining a simple relationship which can be used to design final NPs size from 15 to hundreds nanometers. These particles were subsequently subjected to test of cell uptake and toxicity in order to evaluate their behavior in biological environment.