Y3+ embedded in polymeric nanoparticles: Morphology, dimension and stability of composite colloidal system

Radiolabeled nanoparticles are promising tools in cancer diagnosis and therapy. Moreover, yttrium-90 (90Y) is a good candidate as suitable β− emitting radioisotope for a new approach to radio-guided surgery (RGS) proposed by some researchers of our group. In this work, we developed new composite nanoparticles, based on polymethylmethacrylate (PMMA), and poly(methylmethacrylate-co-acrylic acid), P(MMA/AA), embedded with yttrium ion (89Y3+), as a first step for the development of new 90Y3+ based nanocomposites. The composite nanoparticles were synthesised by emulsion polymerization technique, in the presence of potassium persulfate (KPS) as radical initiator, toluene as cosolvent, diethylenetriamine penta acetic acid dianhydride (DTPA) as chelating agent, using different MMA/89Y3+ molar ratios. The yttrium doped polymeric nanoparticles were characterized by means of FTIR spectroscopy, SEM-EDX, AFM, and DLS measurements. The influence of experimental parameters, such as cosolvent and reaction time, on morphology and dimension of composite nanoparticles was investigated, and monodispersed nanospheres with diameters from 20 nm to 400 nm were obtained. The composite material was purified and studied by means of DLS to confirm the colloid stability in water solution at different temperatures (25 °C and 37 °C) up to 3 weeks.