(623h) Drug Release Study of a Tripartite Gold Nanoconjugate for Spinal Cord Injury Treatment

Gold nanoparticles (AuNPs) show great potentials for biomedical applications with regard to both diagnostic and therapeutic utilities. As a drug delivery carrier, AuNPs enable versatile conjugation chemistry with drugs and proteins with the ease of tuning particle size, shape, and surface chemistry. Our work focuses on the engineering of AuNPs/drug conjugates for treating respiratory dysfunction resulted from high-level of spinal cord injury (SCI). Respiratory problems are common and often lead to fatal consequences caused by SCI. In SCI patients, systemic administrations of drugs that improve respiratory function also cause harmful side effects. By chemically conjugating the AuNP drug carrier to a transporter protein (wheat germ agglutinin coupled to horseradish peroxidase or WGA-HRP) and to theophylline (a SCI drug or THP), a single administration of the nanoconjugate improved diaphragmatic activity at a much lower dosage than the free drug dosage. This talk will describe the synthesis and characterization of the nanoconjugate, particularly, the use of thermogravimetric analysis (TGA) and laser desorption ionization mass spectrometry (LDI-MS) to determine the numbers of drug molecules conjugated to AuNP. This talk will further describe the drug release profiles of the gold nanoconjugate in buffer and in vivo. For the in vivo study, recovery was found 72 hours after injection, which was 24 hours after the detection of the nanoconjugate in the targeting site. The in vivo results are correlated with the results from the drug release study in buffer and artificial spinal cord fluid using mass spectrometry. This study demonstrates a novel nanoconjugate capable of targeted drug delivery for the treatment of respiratory dysfunction associated with SCI.