Novel particulate systems for the delivery of an oligonucleotide decoy to Nuclear Factor-kappaB: a potential strategy for treating cystic fibrosis

Objectives To develop safe and effective particulate systems for cystic fibrosis gene therapy by an oligonucleotide decoy to Nuclear Factor-kB. Background/Rationale Decoy oligonucleotide (decoy ODN) able to interfere with NF-kB pathway may be of great help in reducing NF-kB mediated pulmonary chronic inflammation, which is the primary cause of bronchioectasis, respiratory failure and death of CF patients. To overcome issues related to the use of oligonucleotide (ODN) in therapy, delivery through poly(lactide-co-glycolide) (PLGA) microparticles, able to protect ODN toward the biological environment and/or release the drug in a controlled way, has been suggested. Recent studies indicate that PLGA microparticles allow an increase of ODN biological stability, are able to maintain its hybridization capability and provide a sustained ODN pharmacological activity. Conceiving PLGA microspheres for CF treatment, another important challenge to be taken into account is their potential in ODN pulmonary delivery. On this matter, recent data indicate that adequately formulated PLGA particles may effectively transport high-molecular weight drugs to the lungs. Preliminary results In our previous studies, PLGA microspheres for ODN delivery have been developed. We investigated the potential of PLGA microspheres as delivery systems for a decoy phosphorotioate ODN against NF-kB in RAW 264.7 macrophages stimulated with lipopolysaccharide. In particular, in vitro incubation of macrophages with decoy ODN-releasing microspheres resulted in an inhibition of NF-kB activation eighty-times higher than that achieved with naked decoy ODN. We have also demonstrated that the use of polyethylenimine, a cationic polymer, can be of help in improving cell internalization and nuclear characterization of ODN. These findings suggest that due to their sustained release properties PLGA microspheres allow the full optimization of ODN pharmacokinetics. More recently, we have designed and developed PLGA-based dry powders intended for drug pulmonary delivery. In vitro/in vivo experimental results suggest that large porous particles (LPP) with flow properties and size suitable for aerosolization and deposition in deep regions of the lung following inhalation can be achieved. Project description (experimental plan, methods, timetable) The project will be carried out in two years. PLGA microspheres loaded with a decoy ODN against NFkB, eventually containing PEI, will be developed. Particular attention will be paid to particle for pulmonary delivery by evaluating in depth their aereodynamic properties which will affect their potential as pulmonary carriers. All the particles will be fully characterized for morphology, size, loading efficiency and in vitro release. The optimized systems will be tested on specific CF cell lines and animal models of CF. Anticipated output Research results such as patents, scientific publications and presentations at international symposia can be expected. We believe that this will occur in a reasonable short period (by the end of the 1st year) due to the advanced knowledge and expertise of the research teams involved in the project as well as the fact that the groups already collaborate on similar topics. Relevance to Italian CF Foundation The project could be of great interest for pharmaceutical and biotechnological industries involved in the development of novel therapeutic approaches for rare diseases. In fact, thanks to a specific EU legislation, industries which desire to sponsor an orphan drug can be the recipients of several economic incentives. Due to the high industrial applicability of the research, CF foundation could attract industrial attention and benefit of new opportunity of financial support.