Development and characterization of polo-like kinase 2 loaded nanoparticles-A novel strategy for (serine-129) phosphorylation of alpha-synuclein

Polo like kinase 2 (PLK2), a serine/threonine serum inducible kinase, has been proposed to be the major factor responsible for phosphorylating alpha-synuclein (alpha-syn) at Serine-129 (Ser-129) in Parkinson's disease (PD). A suitable strategy to gain insights into PLK2' s biological effects might be to increase PLK2 intracellular levels with the aim of reproducing the slow progressive neuronal changes that occur in PD. The goal of this study was to develop and characterize a novel drug delivery system (DDS) for PLK2 cytosolic delivery using Total recirculating one machine system (TROMS), a technique capable of encapsulating fragile molecules while maintaining their native properties. A protocol for nanoparticle (NP) preparation using TROMS was set up. NPs showed a mean diameter of 257 +/- 15.61 nm and zeta potential of -16 +/- 2 mV, suitable for cell internalization. TEM and SEM images showed individual, spherical, dispersed NPs. The drug entrapment efficacy was 61.86 +/- 3.9%. PLK2-NPs were able to enter SH-SY5Y cells and phosphorylate alpha-syn at Ser-129, demonstrating that the enzyme retained its activity after the NP manufacturing process. This is the first study to develop a DDS for continuous intracellular delivery of PLK2. These promising results indicate that this novel nanotechnology approach could be used to elucidate the biological effects of PLK2 on dopaminergic neurons. (C) 2016 Elsevier B.V. All rights reserved.