RESUMO
The cause of the Jones-Ray effect has been controversially debated for years. Ultrafine gas bubbles were employed to lessen the surface excess of the surface-active impurities adsorbing to the air/water interface of the salt solutions, which would lead to a direct shift in surface tension observable by the Wilhelmy plate method. It was concluded in this study that once the surface excess of the inevitable impurities in the salts is lessened by the introduction of ultrafine gas bubbles, which possess great air/water interfacial area, the Jones-Ray effect becomes nonobservable. Therefore, our finding hypothesized that the Jones-Ray effect might not originate from salts.
RESUMO
The application of ultrafine bubbles as drug carriers in drug delivery is still in its developmental stage; it is important to obtain a thorough understanding of the factors affecting the formation and stability of drug carrier matrices. In this study, the polyethylene glycol (PEG)-conjugated human serum albumin (HSA)-based ultrafine bubble simulating the physiological electrolyte concentration in human blood (154 mM) for quercetin delivery was investigated. Optical absorbance measurements, surface tension measurements, and fluorescence laser imaging were also employed to assess the plausibility of polymer-conjugated albumin-stabilized ultrafine bubbles in drug loading and drug release. The incorporation of PEG/HSA into the system illustrated a significant enhancement in the matrix's stability as confirmed by surface tension measurements and drug-loading efficiency achieving approximately 90%. In addition, in vitro drug release was performed by the application of high-frequency ultrasound, indicating more than 40% of the loaded quercetin was astonishingly liberated within 5 minutes of exposure.