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The development of biomaterials to treat, repair, or reconstruct the human body is an increasingly important component of materials research. Collaboration between materials researchers and their industrial and clinical partners is essential for the development of this complex field. To demonstrate the importance of these interactions, two articles in this issue focus on advances in biomaterials relating to the use of colloidal systems for transport, drug delivery, and other medical applications. These articles were coordinated by Dominique Muster (Université Louis Pasteur, Strasbourg) and Franz Burny (Hôpital Erasme, Brussels). The following is the second of these two articles.There are two important objectives in drug delivery research. The first is to maximize the effectiveness of drugs by increasing the amount of drug reaching the target tissue while sparing other tissues the deleterious effects of the drug. The second is to control the release of a drug, so that the period of optimal drug concentration in the target tissue is maximized. A numbe r of different Systems have been investigated to achieve these objectives, including soluble polymeric delivery Systems and a range of colloidal drug delivery forms such as liposomes, emulsions, micelles, microcapsules, microparticles, and nanoparticles. This article focuses on polymeric materials for the production of micro- or nanoparticle Systems for dru g delivery by injection, and their characterization and Performance in vivo.Colloidal particles have a number of advantages as drug delivery Systems; they are easy to prepare, have the potential for high drug loading, and release of the drug can be controlled. However, without surface modification, colloidal particles are difficult to target because they are directed largely to the liver and spieen after intravenous injection. The reasons for this can be found in the context of the body's defenses. In order to protect against disease, the body has a complex System to ensure that invading microorganisms are identified and neutralized at the earliest possible opportunity. Most parasitic or invading organisms which pose a threat are particulate in form, and thus any colloidal drug delivery System will have to evade detection by these mechanisms in order to reach its target.

Development of a high-performing hybrid rocket system that employs 90% hydrogen peroxide and 3-D printable thermoplastic materials is reported. Traditionally, highgrade peroxide has been employed as a monopropellant using noble-metal catalysts to initiate thermal decomposition. Catbeds beds are expensive, heavy, and contribute no propulsive mass to the system. Catbeds exhibit limited operational lifetimes, and are often rendered inactive due to the high temperatures of thermal decomposition. The presented alternative thermally-decomposes the injected peroxide stream using an electrostatic ignition system, where as a moderate electric field is introduced to the additively layered ABS fuel grain. Electrostatic arcs are induced within the 3-D printed surface features, and produce sufficient pyrolyzed fuel vapor to induce spontaneous combustion when a flow of gaseous oxygen is introduced. Heat released is sufficient to thermally decompose the injected peroxide stream. The liberated heat and oxygen from decomposition drive full combustion along the length of the fuel grain. Gaseous oxygen pre-leads as small as 250ms reliably initiate combustion. Multiple on-demand relights are provided with this system. Achieved laboratory specific impulse values exceed 215s under ambient conditions, with a projected vacuum value exceeding 300s. Density specific impulse values exceeding 4000N-s/liter are achievable with this system.

<p><b>Urban environments are increasing in size and influence across the landscape of the world. As cities increase in number, size, and population, the influence that these modified anthropogenic spaces and the humans dwelling within them have on wildlife is becoming increasingly intense. More frequent interactions between humans and wildlife have driven species to either adapt, tolerate, or avoid urban spaces entirely. While the impacts of urban life on avifauna have been well studied globally, little is known about the response of the endemic forest-dwelling birds of New Zealand to the novel challenges presented by cities. Furthermore, the majority of existing studies have focused on northern hemisphere passerine species. The naive endemic avifauna of New Zealand, including the many threatened psittacine (parrot) species, have been subject to limited study regarding habituation and response to urban landscapes. Understanding how wildlife responds to urban environments, and the factors that drive differences in behaviour and space use, is essential to managing urban populations and planning future reintroductions of wildlife into cities.</b></p> <p>North Island kākā (Nestor meridionalis septentrionalis) were reintroduced to Wellington City in 2002, with the release of six individuals into Zealandia ecosanctuary. Kākā are a deeply endemic, threatened forest-dwelling parrot species The population has since grown and expanded across many suburbs of the city, increasing the frequency of interaction between kākā and both the urban environment, and people. This thesis investigates the influence of the urban environment and human presence on the spatial distribution, behaviour, and risk perception of kākā in the Wellington and the Kāpiti Coast Regions of New Zealand. The findings of this thesis show that human presence and the urban environment did not directly influence the distribution or behaviour of kākā. Time of day strongly influenced investment in vigilance and foraging behaviour, and land cover type strongly affected investment in foraging and preening behaviour. Urban land cover was not significant in explaining differences in behaviour. Time of day was the most significant explanatory factor for the relative abundances of kākā observed. The distribution of kākā throughout the landscape was also strongly influenced by the presence of Zealandia, with far greater densities and relative abundances of kākā within the sanctuary compared to the urban reserves of Wellington city. Overall, findings in this study suggest that kākā behaviour and distributions are much more strongly influenced by resource availability than by human presence and the urban environment directly. Further research should be conducted to investigate the risk perception and behavioural flexibility of urban kākā. This is especially important for the ongoing management of Wellington’s kākā population, and to better inform future urban reintroduction efforts.</p>

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