Preventing Static Biofilm Formation of Staphylococcus aureus on Different Types of Surfaces Using Microbubbles.

Bacterial fouling and biofilm formation on surfaces have been ongoing problems in real life as well as in the medical field. Different approaches have been taken to tackle the issues, from costly surface modification to antibiotic-delivering strategies. In this study, we examined the potential of using stabilized microbubbles (MBs) to shield against bacterial adhesion. Three types of surfaces were tested: hydrophilic glass (hydrophilic surface), neutral hydrophobic polystyrene (PS)-coated surfaces, and negatively charged hydrophobic octadecyltrichlorosilane (OTS)-coated surfaces. By evaluating the colony-forming unit (CFU) values from each surface, MBs stabilized by 0.05 mM SDS were shown to only produce significant reduction of Staphylococcus aureus adhesion on PS surfaces, up to 60.29 and 82.32% compared to no-MB PS surfaces, and no-MB uncoated surfaces, correspondingly, due to the appropriate size, stability, and negative charges of the MB shielding layer. On the other hand, OTS coatings had an intrinsic antiadhesion effect (69.83% compared to uncoated surface), given that the negatively charged OTS-aqueous interface or surface porosity nature of the coating prohibited the attachment of MBs, leading to the elimination of the antifouling effect of MBs. Ultimately, MBs gave better shielding results than surface modification when compared to uncoated surfaces and hence can be applied more widely.

Utilization of Ultrafine Gas Bubbles to Investigate the Jones-Ray Effect of Diluted Salt Solutions.

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.

Utilizing polymer-conjugate albumin-based ultrafine gas bubbles in combination with ultra-high frequency radiations in drug transportation and delivery.

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.