The development of synthetic polynucleotide delivery systems is hampered by the extreme instability of these colloidal suspensions as liquid formulations. This instability also affects basic research by forcing scientists to conduct experiments with vector preparations that are prone to significant batch-to-batch variability. As a result, there is interest in developing methods that would allow synthetic vectors to be formulated as stable, dehydrated preparations that could be prepared in large batches, and shipped and stored at ambient temperatures. The work proposed here focuses on developing methods of dehydrating synthetic vectors such that their physical characteristics and biological activity are maintained during both acute lyophilization stress and prolonged storage. Previous work on these problems has demonstrated that stabilization can be achieved during acute lyophilization stress by employing high amounts of sugars. Unfortunately, the amount of sugar needed for stabilization is not osmotically compatible with intramuscular or subcutaneous injection; the preferred method of administration for many applications, e.g., DNA vaccines. We propose mechanistic studies to determine the causative effects of vector aggregation (the major mechanism of damage) during acute lyophilization stress, and pursue strategies that achieve stability at isotonic osmolalities. The findings from these initial studies will be applied to experiments investigating two approaches to enhance storage stability. In the first approach, formulations will be directly assessed for their ability to reduce the accumulation of reactive oxygen species during storage. These experiments utilize a novel fluorescence technique that, for the first time, allows the generation of oxygen radicals in dried preparations to be monitored. The second approach is consistent with recent reports and questions the conventional dogma in the field of solid-state stability that """"""""drier is better"""""""". Ultimately, the results from these approaches will be combined in a 2-year storage stability study on fully-optimized formulations. Recognizing that different types of synthetic vectors are being optimized for gene/polynucleotide delivery, these experiments employ different model vectors (e.g., lipoplexes and polyplexes) in order to develop rational formulation guidelines that are generally applicable to the stabilization of macromolecular complexes (e.g., vaccines, viruses, nanoparticles) during freeze-drying and storage. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
1R01EB005476-01A2
Application #
7095380
Study Section
Biomaterials and Biointerfaces Study Section (BMBI)
Program Officer
Moy, Peter
Project Start
2006-04-01
Project End
2010-01-31
Budget Start
2006-04-01
Budget End
2007-01-31
Support Year
1
Fiscal Year
2006
Total Cost
$242,550
Indirect Cost
Name
University of Colorado Denver
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045
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Xu, Long; Anchordoquy, Thomas (2011) Drug delivery trends in clinical trials and translational medicine: challenges and opportunities in the delivery of nucleic acid-based therapeutics. J Pharm Sci 100:38-52
Xu, Long; Anchordoquy, Thomas J (2010) Effect of cholesterol nanodomains on the targeting of lipid-based gene delivery in cultured cells. Mol Pharm 7:1311-7
Anchordoquy, T J; Molina, M dC; Kempner, E S (2009) A radiation target method for size determination of supercoiled plasmid DNA. Anal Biochem 385:229-33
Yu, Jinxiang; Anchordoquy, Thomas J (2009) Synergistic effects of surfactants and sugars on lipoplex stability during freeze-drying and rehydration. J Pharm Sci 98:3319-28
Yu, Jinxiang; Anchordoquy, Thomas J (2009) Effects of moisture content on the storage stability of dried lipoplex formulations. J Pharm Sci 98:3278-89
Molina, Marion D C; Anchordoquy, Thomas J (2008) Degradation of lyophilized lipid/DNA complexes during storage: the role of lipid and reactive oxygen species. Biochim Biophys Acta 1778:2119-26
Molina, Marion D C; Anchordoquy, Thomas J (2008) Formulation strategies to minimize oxidative damage in lyophilized lipid/DNA complexes during storage. J Pharm Sci 97:5089-105
Molina, Marion d C; Anchordoquy, Thomas J (2007) Metal contaminants promote degradation of lipid/DNA complexes during lyophilization. Biochim Biophys Acta 1768:669-77