Gas microbubbles, stabilised by a surfactant or polymer coating, have become well established over the past 20–30 years as the most effective type of contrast agent available for ultrasound radiography. More recently, their potential for use in therapeutic applications including targeted drug delivery, gene therapy, thrombolysis and focused ultrasound surgery has also been investigated. Developments in both diagnostic and therapeutic applications have greatly increased the need for more advanced preparation technologies which provide a high degree of control over microbubble size, composition, stability and uniformity. Conventional processing techniques such as sonication and high shear emulsification offer high yield and low cost production but poor control over microbubble size and uniformity. This is being addressed by the development of new technologies, such as membrane emulsification, inkjet printing, electrohydrodynamic atomisation and microfluidic processing which offer significant improvements in terms of control over microbubble characteristics. The aim of this paper is to review the range of techniques available for microbubble preparation and how these have evolved to keep pace with advances in clinical practice.

A new route consisting of simultaneous centrifugal spinning and solution blowing to form polymer nanofibers is reported. The fiber diameter (60–1000 nm) is shown to be a function of polymer concentration, rotational speed, and working pressure of the processing system. The fiber length is dependent on the rotational speed. The process can deliver 6 kg of fiber per hour and therefore offers mass production capabilities compared with other established polymer nanofiber generation methods such as electrospinning, centrifugal spinning, and blowing. magnified image

Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

In this invited feature article, the invention of pressurized gyration in 2013 and its subsequent development into sister processes such as pressurized melt gyration, infusion gyration, and pressure‐coupled infusion gyration is elucidated. The fundamentals of these processes are discussed, elucidating how these novel methods can be used to facilitate mass production of polymeric fibers and other morphologies. The effects of the main system parameters: rotational speed and gas pressure, are discussed along with the influence of solution parameters such as viscosity and polymer chain entanglement. The effect of flow of material into the gyrator in infused gyration is also illustrated. Examples of many polymers that have been subjected to these processes are discussed and the applications of resulting products are illustrated under several different research themes such as, tissue engineering, drug delivery, diagnostics, hydrogels, filtration, and wound healing.

We develop a simple, fast and economical surface treatment under ambient temperature to improve the hydrophilicity and osteoconductivity of polyetheretherketone (PEEK) for bone implant applications. A major challenge in bone implants is the drastic difference in stiffness between traditional implant materials (such as titanium and stainless steel) and human bone. PEEK is biocompatible with an elastic modulus closely matching that of human bone, making it a highly attractive alternative. However, its bio-inert and poorly hydrophilic surface presents a serious challenge for osseointegration. Sulfonation can improve hydrophilicity and introduce bioactive sulfonate groups, but PEEK sulfonation has traditionally been applied for fuel cells, employing elevated temperatures and long reaction times to re-cast PEEK into sulfonated films. Little research has systematically studied PEEK surface modification by short reaction time (seconds) and ambient-temperature sulfonation for biomedical applications. Here, we investigate three ambient-temperature sulfonation treatments under varying reaction times (5–90 s) and evaluate the hydrophilicity and morphology of 15 modified PEEK surfaces. We establish an optimal treatment using 30 s H ₂ SO ₄ followed by 20 s rinsing, and then 20 s immersion in NaOH followed by 20 s rinsing. This 30 s ambient-temperature sulfonation is found to be more effective than conventional plasma treatments and reduced PEEK water contact angle from 78° to 37°.