Kjar, Andrew; Heap, Mitchell; Wadsworth, Ian; Vargis, Elizabeth; Britt, David (Utah State University)
Faculty Advisor: Britt, David (College of Engineering, Biological Engineering Department); Vargis, Elizabeth (College of Engineering, Biological Engineering Department)
Quercetin is a flavonoid that exhibits antiviral activity against cytomegalovirus infection, the leading cause of non-genetic sensorineural hearing loss in infants. However, delivering quercetin as an antiviral treatment is challenging as it is sparingly soluble in water and highly susceptible to oxidation once solubilized. This study investigated quercetin encapsulation in micelles formed from self-assembled nanocariiers of differing hydrophobic and hydrophilic chain lengths (specifically, F127, P123, and F68). Samples were investigated weekly for two months using UV-vis spectroscopy and dynamic light scattering to determine quercetin chemical stability and micelle size, respectively. Free quercetin and F68-encapsulated quercetin oxidized within one week in PBS, while quercetin encapsulated by Pluronics F127 and P123 remained stable and encapsulated over two months. Pluronics F127 and F68 have similar PEO chain lengths, but the lower hydrophobic PPO content of F68 was insufficient to allow quercetin-loaded F68 to form stable carriers. As a consequence, F68 also did not protect quercetin against oxidation. The decreased PEO chain length of P123 did not inhibit micelle formation nor oxidative protection. These data suggest the length of the hydrophilic chain is not a determining factor in the chemical stability of encapsulated quercetin. Instead, shielding effects appear to correlate to longer hydrophobic segment lengths, as in F127 and P123.
Conclusions: The ability of the selected Pluronics to encapsulate quercetin in stable micelles and inhibit oxidation was highly dependent on PEO/PPO ratios. This work indicates selection of the appropriate delivery vehicle is necessary to improve quercetin's efficacy as an antiviral and antioxidant for inhibiting CMV and associated SNHL.