Until recently the spectacular developments in nanotechnology have been with little regard to their potential effect on human health and the environment. There are no specific regulations on nanoparticles except existing regulations covering the same material in bulk form. Difficulties abound in devising such regulations, beyond self-imposed regulations by responsible companies, because of the likelihood of different properties exhibited by any one type of nanoparticle, which are tuneable by changing their size, shape and surface characteristics. Green chemistry metrics need to be incorporated into nanotechnologies at the source. This review scopes this issue in the context of potential health effects of nanoparticles, along with medical applications of nanoparticles including imaging, drug delivery, disinfection, and tissue repair. Nanoparticles can enter the human body through the lungs, the intestinal tract, and to a lesser extent the skin, and are likely to be a health issue, although the extent of effects on health are inconclusive. Nanoparticles can be modified to cross the brain blood barrier for medical applications, but this suggests other synthetic nanoparticles may unintentionally cross this barrier.

Organic chemistry is continually evolving to improve the syntheses of value added and bioactive compounds. Through this progression, a concomitant advancement in laboratory technology has occurred. Many researchers now choose to mediate transformations in continuous-flow systems given the many benefits over round bottom flasks. Furthermore, reaction scale up is often less problematic as this is addressed at the inception of the science. Although single-step transformations in continuous-flow systems are common, multi-step transformations are more valuable. In these systems, molecular complexity is accrued through sequential transformations to a mobile scaffold, much like an in vitro version of Nature's polyketide synthases. Utilizing this methodology, multi-step continuous-flow systems have improved the syntheses of active pharmaceutical ingredients (APIs), natural products, and commodity chemicals. This Review details these advancements while highlighting the rapid progress, benefits, and diversification of this expanding field.

Graphite is exfoliated into graphene by shearing vortex fluidic films of N-methyl-pyrrolidone (NMP), as a controlled process for preparing oxide free graphene, and for exfoliating the corresponding boron nitride sheets.

p-Sulfonatocalix[4,5,6,8]arenes are versatile building blocks, able to assemble into ‘molecular capsule’ arrays based on two calixarenes, as well as a variety of other structural motifs, with the extended structures dominated by the formation of bilayers. For p-sulfonatocalix[4]arene, assembly into nanometre scale spheroids (of either icosahedral or cuboctahedral geometries) as well as nanotubules (all of which take on structural features akin to those of viruses) is possible, depending on the guest molecules and lanthanides present in solution.

Mats of electrospun chitosan nanofibers were found effective in immobilizing microalgal cells. These immobilized microalgal cells were also used as a durable model system for wastewater treatment which has been demonstrated by the removal of around 87% nitrate from liquid effluents ([NO₃ ⁻-N]_initial 30 mg L⁻¹). Virtuous nitrate removal rates were derived by superimposing physicochemical adsorption and biological nutrient consumption phenomena for chitosan and microalgae, respectively.