Nanoparticle Gene Therapy for Parkinson's Disease

The proposed studies will use a novel nanoparticle technology that allows nucleic acids (DNA) to be compacted near their theoretical limit; this technology almost duplicates the compaction efficiency of viruses. Proprietary techniques will be used to compact DNA plasmids into nanoparticles with diameters in the range of 8-20 nanometers. We will use this technology to transfect brain cells so that the transfected cells express proteins that are beneficial to the cell's survival. DNA compacted into nanoparticles has been shown to effectively transfect nondividing cells, including growth-arrested neuroblastoma cells [1], and may be a viable system for the delivery of neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF), to dopamine neurons. Compacted DNA nanoparticles are not immunogenic in lung or after direct injection into the mouse eye and may circumvent the problems of immunogenicity that are inherent with some viral vectors [2, 3]. We have preliminary data showing compacted DNA nanoparticles can be used to successfully induce transgene expression of reporter genes in the mouse or rat striatum (see Figure I). The proposed studies will use DNA plasmids encoding for a CMV or ubiquitin promoter and GDNF. These DNA plasm ids will be compacted into nanoparticles and injected directly into the striatum of rats at various concentrations. We will use several protein assays and immunohistochemistry to determine whether compacted GDNF DNA nanoparticles can successfully transduced brain cells, induce transgene expression of GDNF in brain tissue, and also determine the time period of trans gene expression. At the same time we will determine the extent of any immunogenic response to this treatment by labeling brain sections for various inflammatory markers. We will also determine whether this type of non-viral gene therapy can be used to protect dopamine neurons against a neurotoxic insult. Successful results from this study will provide proof of principle that compacted DNA nanoparticles can be used to delivery DNA to brain cells for therapeutic purposes.