Search

Inthis work, the biosensing and antibacterial capabilities ofPVA-lysozyme microbubbles have been explored. Gas-filled PVA-lysozymemicrobubbles with and without gold nanoparticles in the diameter rangeof 10 to 250 μm were produced using a single-step pressurizedgyration process. Fluorescence microscopy showed the integration ofgold nanoparticles on the shell of the microbubbles. Microbubblesprepared with gold nanoparticles showed greater optical extinctionvalues than those without gold nanoparticles, and these values increasedwith the concentration of the gold nanoparticles. Both types of microbubblesshowed antibacterial activity against Gram-negative Escherichiacoli(E. coli), with the bubbles containingthe gold nanoparticles performing better than the former. The conjugationof the microbubbles with alkaline phosphatase allowed the detectionof pesticide paraoxon in aqueous solution, and this demonstrates thebiosensing capabilities of these microbubbles. [ABSTRACT FROM AUTHOR]

There has recently been considerable interest in the development of devices for the preparation of monodisperse microbubble suspensions for use as ultrasound contrast agents and drug delivery vehicles. These applications require not only a high degree of bubble uniformity but also a maximum bubble size of 8 m, and this provides a strong motivation for developing an improved understanding of the process of bubble formation in a given device. The aim of this work was to investigate bubble formation in a T-junction device and determine the influence of the different processing parameters upon bubble size, in particular, liquid viscosity. Images of air bubble formation in a specially designed T-junction were recorded using a high-speed camera for different ratios of liquid to gas flow rate (Ql/Qg) and different liquid viscosities (l). It was found that theoretical predictions of the flow profile in the focal region based on analysis of axisymmetric Stokes flow were accurate to within 6% when compared with the experimental data, indicating that this provided a suitable means of describing the bubble formation process. Both the theoretical and experimental results showed that Ql/Qgand lhad a significant influence upon bubble formation and eventual size, with higher flow rates and higher viscosities producing smaller bubbles. There were, however, found to be limiting values of Ql/Qgand lbeyond which no further reduction in bubble size was achieved. [ABSTRACT FROM AUTHOR]

The exploration of nanocomposites has gained a strong research following over the last decade. These materials have been heavily exploited in several fields, with applications ranging from biosensors to biomedicine. Among these applications, great advances have been made in the field of microbiology, specifically as antimicrobial agents. This review aims to provide a comprehensive account of various nanocomposites that elucidate promising antimicrobial activity. The composition, physical and chemical properties, as well as the antimicrobial performance of these nanocomposites, are discussed in detail. [ABSTRACT FROM AUTHOR]

The vaginal route is increasingly being considered for both local and systemic delivery of drugs, especially those unsuitable for oral administration. One of the opportunities offered by this route but yet to be fully utilised is the administration of microbicides. Microbicides have an unprecedented potential for mitigating the global burden from HIV infection as heterosexual contact accounts for most of the new infections occurring in sub-Saharan Africa, the region with the highest prevalent rates. Decades of efforts and massive investment of resources into developing an ideal microbicide have resulted in disappointing outcomes, as attested by several clinical trials assessing the suitability of those formulated so far. The highly complex and multi-level biochemical interactions that must occur among the virus, host cells and the drug for transmission to be halted means that a less sophisticated approach to formulating a microbicide e.g. conventional gels, etc may have to give way for a different formulation approach. Nanotechnology has been identified to offer prospects for fabricating structures with high capability of disrupting HIV transmission. In this review, predominant challenges seen in microbicide development have been highlighted and possible ways of surmounting them suggested. Furthermore, formulations utilising some of these highly promising nanostructures such as liposomes, nanofibres and nanoparticles have been discussed. A perspective on how a tripartite collaboration among governments and their agencies, the pharmaceutical industry and academic scientists to facilitate the development of an ideal microbicide in a timely manner has also been briefly deliberated. [ABSTRACT FROM AUTHOR]