(256b) Gold Nanoconjugates: Targeted Drug Delivery, Drug Release, and Biodistribution

Gold nanoparticles (AuNPs) show great potentials in biomedical applications because of their versatile surface chemistry, ease of imaging, and tenability to take advantage of the blood-brain barrier transport mechanisms. AuNPs have also been found to be among the most benign nanomaterials partially attributed to the inertness of bulk gold. As a consequence, AuNPs are widely investigated for targeted delivery of drugs, genetic materials, antigens, and diagnostic agents. To act as a drug carrier, AuNP enables various conjugation chemistry with drugs and proteins. Also, the particle size, shape, surface chemistry of the AuNP can be precisely tuned. This poster describes a sample of a tripartite nanoconjugate comprised of an AuNP drug carrier chemically conjugated to a transporter protein (wheat germ agglutinin coupled to horseradish peroxidase or WGA-HRP) and to the spinal cord injury (SCI) drug, theophylline. Our results show that a single administration of the nanoconjugate improved diaphragmatic activity at a dosage lower than the effective systemic drug dose and restored majority of the respiratory drive. The effects lasted for up to 14 days. A biodistribution study using inductively coupled plasma mass spectrometry on the same animal model shows a successful targeting of the nanoconjugate in the respiratory neurons located in the medulla. By using of thermogravimetric analysis and laser desorption ionization mass spectrometry we determined the numbers of drug molecules conjugated to AuNP. All the AuNPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, dynamic light scattering, and atomic force microscopy.