Self-powered artificial nanomotors are currently attract-9 ing increased interest as mimics of biological motors but also as 10 potential components of nanomachinery, robotics, and sensing devices. 11We have recently described the controlled shape transformation of 12 polymersomes into bowl-shaped stomatocytes and the assembly of

Herein, we report a robust way for the formation of biodegradable poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) polymersomes, via direct hydration of a highly concentrated block copolymer/oligo(ethylene glycol) solution. Polymersomes with variable membrane thickness were formed under relatively mild conditions in a short time, by changing the hydrophobic block length. Plunge freezing followed by cryo transmission electron microscopy (Cryo-TEM) was utilized to visualize the morphology of newly-formed polymersomes in their native condition. An MTT cytotoxicity study showed that the as-prepared polymersomes have good biocompatibility to hCMEC/D3 brain endothelial cells. As this method does not involve the use of small molecular organic solvent, sonication or freeze-thawing steps, it can offer the opportunity to form biodegradable polymersomes on-site. The work may facilitate the bench-to-bedside translation of biodegradable polymersomes as robust drug nanocarriers. † Electronic supplementary information (ESI) available: DLS, Cryo-TEM images of polymersome after dialysis. SeeThis journal is

1. To determine whether a wrist cuff is necessary to measure the forearm blood flow correctly, we studied the effects of wrist cuff inflation to supra-venous and supra-systolic pressure values over a large range of forearm blood flow values: in the basal state, during post-occlusive hyperaemia of the hand, and during heating of the hand with warm air. Eleven healthy men participated, and the study was carried out at two different ambient temperatures of 20 and 25 degrees C. 2. In the basal state, the measured forearm blood flow was lowest with the wrist cuff at supra-systolic pressure. With the wrist cuff at supra-venous pressure the forearm blood flow was also lower than with an uninflated cuff, but only significantly so when the basal forearm blood flow was higher (at a room temperature of 25 degrees C). 3. During post-occlusive hyperaemia, inflating the wrist cuff to supra-systolic pressure produced the lowest forearm blood flow value at both room temperatures. In addition, with the wrist cuff at supra-venous pressure, forearm blood flow values were lower than with the uninflated cuff, but the supra-venous cuff pressure was clearly less efficient in excluding the hand blood flow than the supra-systolic cuff pressure. 4. During heating of the hand, both supra-systolic and supra-venous cuff pressures were effective in excluding the hand blood flow at both room temperatures. The forearm blood flow measured with the wrist cuff at supra-systolic pressure was lower than that measured with the wrist cuff at supra-venous pressure, but the difference was only significant at a room temperature of 20 degrees C. 5. In conclusion, we have demonstrated that a wrist cuff at supra-systolic pressure is most appropriate for the exclusion of the hand circulation in order to measure the forearm blood flow correctly.

Polymersomes are a class of artificial liposomes, assembled from amphiphilic synthetic block copolymers, holding great promise toward applications in nanomedicine. The diversity in polymersome morphological shapes and, in particular, the precise control of these shapes, which is an important aspect in drug delivery studies, remains a great challenge. This is due to a lack of general methodologies that can be applied and the inability to capture the morphologies at the nanometer scale. Here, we present a methodology that can accurately control the shape of polymersomes via the addition of polyethylene glycol (PEG) under nonequilibrium conditions. Various shapes including spheres, ellipsoids, tubes, discs, stomatocytes, nests, stomatocyte-in-stomatocytes, disc-in-discs, and large compound vesicles (LCVs) can be uniformly captured by adjusting the water content and the PEG concentration. Moreover, these shapes undergo nonequilibrium changes in time, which is reflected in their phase diagram changes. This research provides a universal tool to fabricate all shapes of polymersomes by controlling three variables: water content, PEG concentration, and time. The use of the biofriendly polymer PEG enables the application of this methodology in the field of nanomedicine.

Accurate control of the shape transformation of polymersome is an important and interesting challenge that spans across disciplines such as nanomedicine and nanomachine. Here, we report a fast and facile methodology of shape manipulation of polymersome via out-of-equilibrium polymer self-assembly and shape change by chemical addition of additives. Due to its increased permeability, hydrophilicity, and fusogenic properties, poly(ethylene oxide) was selected as the additive for bringing the system out of equilibrium via fast addition into the polymersome organic solution. A new shape, stomatocyte-in-stomatocyte (sto-in-sto), is obtained for the first time. Moreover, fast shape transformation within less than 1 min to other relevant shapes such as stomatocyte and large compound vesicles was also obtained and accurately controlled in a uniform dispersion. This methodology is demonstrated as a general strategy with which to push the assembly further out of equilibrium to generate unusual nanostructures in a controllable and fast manner.