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Nanoparticle-mediated photoporation has arisen as a universal intracellular delivery tool; however, the direct interaction of nanoparticles and cells hampers its clinical translation. Here, we report a uniform contactless intracellular delivery that transfects a large number of cells within a minute and avoids direct contact of nanoparticles and cells, thereby improving the cell viability. Our platform consists of an array of polydimethylsiloxane (PDMS) mixed reduced graphene oxide (rGO) nanoflakes on pyramidal microtips, uniformly distributed at the apex of the tip. The extraordinary optoelectronic properties of rGO were combined with micro-pyramidal cavities to entrap light in micro-cavities and efficiently convert it into heat through multiple reflections and absorptions. As a result, ultralow infra-red laser pulse irradiation could create cavitation bubbles followed by cell membrane deformation and biomolecular delivery. Using this delivery platform, we have achieved the delivery of small to large cargo (668 Da to 465 kDa) in various mammalian cells, including hard-to-transfect H9C2 cardiomyocytes. The best results were achieved for enzyme (465 kDa) delivery with a transfection efficiency and cell viability of 95% and 98%, respectively, in SiHa cells. The highly efficient cargo delivery tool demonstrated a safe and effective approach for cell therapy and diagnostics. [ABSTRACT FROM AUTHOR]

Photothermal nanoparticle-sensitised photoporation is an emerging approach, which is considered an efficient tool for the intracellular delivery of biomolecules. Nevertheless, using this method to achieve high transfection efficiency generally compromises cell viability and uneven distribution of nanoparticles results in non-uniform delivery. Here, we show that high aspect ratio gold nano-burflowers, synthesised in a microfluidic device, facilitate highly efficient small to very-large cargo delivery uniformly using infrared light pulses without sacrificing cell viability. By precisely controlling the flow rates of shaping reagent and reducing agent, high-density (24 numbers) sharply branched spikes (∼80 nm tip-to-tip length) of higher aspect ratios (∼6.5) with a small core diameter (∼45 nm) were synthesised. As produced gold burflower-shape nanoparticles are biocompatible, colloidally stable (large surface zeta potential value), and uniform in morphology with a higher plasmonic peak (max. 890 nm). Theoretical analysis revealed that spikes on the nanoparticles generate a higher electromagnetic field enhancement upon interaction with light pulses. It induces plasmonic nanobubbles in the vicinity of the cells, followed by pore formation on the membrane leading to diverse biomolecular delivery into cells. Our platform has been successfully implemented for uniform delivery of small to very large biomolecules, including siRNA (20–24 bp), plasmid DNA expressing green fluorescent protein (6.2 kbp), Cas-9 plasmid (9.3 kbp), and β-galactosidase enzyme (465 kDa) into diverse mammalian cells with high transfection efficiency and cell viability. For very large biomolecules such as enzymes, the best results were achieved as ∼100% transfection efficiency and ∼100% cell viability in SiHa cells. Together, our findings demonstrate that the spiky gold nano-burflower shape nanoparticles manufactured in a microfluidic system exhibited excellent plasmonic behaviour and could serve as an effective tool in manipulating cell physiology. [ABSTRACT FROM AUTHOR]

Background: Management of foot-drop following stroke can be addressed with ankle-foot orthosis (AFO) or functional electrical stimulation (FES) of the peroneal nerve. There is limited evidence regarding the efficacy of FES as a substitute for a conventional ankle-foot orthosis.Objective: The aim of this study was to compare efficacy of FES against AFO in management of foot-drop in patients following stroke.Materials and Methods: Twenty patients (ten per group) were enrolled in this prospective crossover trial. Group A patients received gait training with AFO during first week followed by training with FES during second week and vice-versa for group B. Outcome parameters following AFO/FES training included Ten-meter, Six-minute walk test and spatiotemporal gait parameters. Patient satisfaction level was assessed using feedback questionnaire. Friedman test and Wilcoxon signed-rank test were performed to compare outcomes between barefoot, AFO and FES. The P value < 0.05 was considered statistically significant.Results: Nineteen males and one female aged 45.5 ± 9.45 years were recruited. Statistically significant improvement was observed in Ten-meter and Six-minute walk tests, gait speed, Timed up and go test (TUG), stance-swing ratio and single-limb support among users of FES as compared to AFO and barefoot. There was no statistical difference observed in other gait parameters. Physiological cost index (PCI) showed trend in improvement among FES users. Patient satisfaction scores were higher for FES users.Conclusions: Quantitative and qualitative results were in favour of FES as compared to AFO and barefoot suggesting that FES can be a potential orthotic intervention in hemiplegic patients. [ABSTRACT FROM AUTHOR]

An article by Belusic and Zupancic described the construction of a finger pulse sensor using a singing greeting card beeper. These authors felt that this beeper made of piezoelectric material could be easily modified to function as a respiratory belt transducer to monitor respiratory movements. Commercially available respiratory belt transducers, such as Pneumotrace also use such piezoelectric material. After modification, the beeper was attached to the chest using Velcro straps. The strain induced on the piezoelectric material of the beeper by the chest movement produces a corresponding voltage change, which can be recorded by a computer using data-acquisition systems or observed using an oscilloscope. The construction of the respiratory belt transducer is described in this article. (Contains 2 figures and 1 footnote.)