Many nanotechnology projects require some form of nanopatterning technique for fabricating the devices, structures and surfaces required in fields ranging from electronics to photonics, security, biotechnology and medicine. Although they may not be visible to the naked eye, the nanometer-sized trenches, ridges, curves and grooves of these patterns and surfaces have a very visible impact. Researchers have developed a wide range of nanopatterning techniques, from top-down methods such as nanoimprint, e-beam or UV lithography to bottom-up techniques such as transfer nanolithography or nanopositioning on DNA or protein scaffolds. A novel technique uses a biofunctionalization approach based on resist-less electron-beam-induced deposition of carbon-containing nanofeatures, that has been developed into a universal biofunctionalization platform. This unique ability can be exploited for biological experiments, where cells respond to the nanoscale density of activating molecules such as antibodies.
Researchers in Israel have found a unique way to affect cancer cells in a rather controllable manner. For example, they can kill these cells in various ways, or they can make them fuse together, as they like. They do so by using functionalized, 20 nm in diameter gold nanospheres and specific, intense laser pulses with a visible wavelength tuned to the plasmonic resonance of those particles. This technique may have an impact on various technologies which require sophisticated cell manipulation for therapeutic and drug development applications. What is unique about this technique is that it is highly controllable and repeatable. The structural stability of the nanospheres even after the strongest laser illumination allows them to deliver the effect over and over again, until the desired result is obtained.
Burn injuries are one of the major global health problems. Every year 195,000 people from all over the world die because of fire alone. A burn injury may damage some or all skin layers and is caused by a hot solid, a hot liquid, or a flame. However, injuries related to electricity, radioactivity, ultraviolet radiation, chemicals and respiratory damage due to smoking are also considered as burn injuries. Besides cleaning the wound and applying various topical anti-microbial agents, wound dressings could be an effective solution in preventing microbial infections for burn care. The suitability of a burn wound dressing depends on a burn type. Conventional dressings are not efficient enough to induce haemostasis, adherence and in holding a moist environment around wound. Due to the advances in the field of nanotechnology, it is now possible to design nanofiber-based wound dressings where an electrospun-nanofibrous layer is applied to a basic support fabric material.
One type of biomolecules, enzymes, regulate almost all chemical reactions involved in numerous biological processes in living organisms and are also widely used in research and industry. Regulation of enzyme activity and stability is very important and has always attracted great attention. Various enzyme regulators, ranging from proteins, peptides, and synthetic organic molecules, have been discovered. Recently, nanomaterials evolve as promising alternatives for enzyme modulation. Nanomaterials provide large surface areas for biomolecule adsorption and can be engineered to present multiple surface functional groups for interacting with biomolecules, such as enzymes and/or their substrates. In a recent study, scientists started to explore the interactions between functionalized graphene oxide and serine proteases, a large family of enzymes with important biomedical and industrial applications.
Modifying living cell by coating them with a nanolayer of functional materials in order to provide them with new structural and functional features has developed into a popular research area for bionanotechnology researchers. In contrast to genetic manipulation techniques, here the functionality of a cell is modified simply by attaching polymers or nanoparticles to the cell's surface. A recent Perspective paper covers the most interesting and promising work in this area and presents an outlook the major potential future directions. The article focuses on on cell encapsulation with Layer-by-Layer (LbL) self-assembly via sequential adsorption of oppositely charged components: polyelectrolytes, nanoparticles, and proteins.
Researchers in China showed that nanoparticles smaller than 10 nm in diameter accumulate more efficiently and penetrate more deeply in tumors relative to their larger counterparts. Their findings have significant implications for the development of nanomaterials to diagnose and treat cancer. The enhanced tumor accumulation of the ultrasmall nanoparticles may be due, at least in part, to their prolonged blood circulation time. In contrast, most nanomaterials that enter the blood are rapidly cleared by tissue-resident macrophages in the liver and spleen. Ultimately, the ability of ultrasmall nanoparticles to diffuse deep within the tumor bulk may enable the design of nanoparticles that can carry therapeutic and diagnostic agents more efficiently into tumors.
Candida albicans is a leading fungal cause of burn infections in hospital settings. The prevalence of invasive candidiasis in burn cases varies widely, but it accounts as high as 23% of severe infection with a mortality rate ranging from anywhere to 14% to 70%. In a recent pre-clinical study, a nitric oxide releasing nanoparticle platform, which has previously been shown to be antibacterial to both gram positive and negative bacteria, as well as an accelerator of wound healing in excisional animal models, was found to be efficacious in clearing candidal burn infections in mice. This study represents one of many pre-clinical investigations demonstrating the efficacy of the NO nanoparticles as a broad spectrum antimicrobial agent as well as wound healing accelerant.
Wound healing is an exceedingly complex process, involving a multitude of signaling pathways, effector molecules, response phases, as well as a moderated balance between all these components. Nitric oxide (NO) plays a critical role in the wound-healing process via antimicrobial properties, modulation of platelet/cytokine function, vasodilatory effects, and promotion of angiogenesis and matrix deposition. While attempts to administer NO to wound areas have shown some promise, the current modalities all suffer from varying drawbacks, such as administration site irritation or the burden of large, expensive equipment. Researchers have now introduced a nanoparticle platform comprised of silane based sol-gel and sugar-derived glasses that can generate, store, and deliver NO in a controlled and sustained manner is utilized to enhance wound healing in immunodeficient mice.