RAFT aqueous dispersion polymerization yields poly(ethylene glycol)-based diblock copolymer nano-objects with predictable single phase morphologies

A poly(ethylene glycol) (PEG) macromolecular chain transfer agent (macro-CTA) is prepared in high yield (>95%) with 97% dithiobenzoate chain-end functionality in a three-step synthesis starting from a monohydroxy PEG113 precursor. This PEG113-dithiobenzoate is then used for the reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). Polymerizations conducted under optimized conditions at 50 °C led to high conversions as judged by 1H NMR spectroscopy and relatively low diblock copolymer polydispersities (Mw/Mn < 1.25) as judged by GPC. The latter technique also indicated good blocking efficiencies, since there was minimal PEG113 macro-CTA contamination. Systematic variation of the mean degree of polymerization of the core-forming PHPMA block allowed PEG113-PHPMAx diblock copolymer spheres, worms, or vesicles to be prepared at up to 17.5% w/w solids, as judged by dynamic light scattering and transmission electron microscopy studies. Small-angle X-ray scattering (SAXS) analysis revealed that more exotic oligolamellar vesicles were observed at 20% w/w solids when targeting highly asymmetric diblock compositions. Detailed analysis of SAXS curves indicated that the mean number of membranes per oligolamellar vesicle is approximately three. A PEG 113-PHPMAx phase diagram was constructed to enable the reproducible targeting of pure phases, as opposed to mixed morphologies (e.g., spheres plus worms or worms plus vesicles). This new RAFT PISA formulation is expected to be important for the rational and efficient synthesis of a wide range of biocompatible, thermo-responsive PEGylated diblock copolymer nano-objects for various biomedical applications

Site-selective protein-modification chemistry for basic biology and drug development.

Nature has produced intricate machinery to covalently diversify the structure of proteins after their synthesis in the ribosome. In an attempt to mimic nature, chemists have developed a large set of reactions that enable post-expression modification of proteins at pre-determined sites. These reactions are now used to selectively install particular modifications on proteins for many biological and therapeutic applications. For example, they provide an opportunity to install post-translational modifications on proteins to determine their exact biological roles. Labelling of proteins in live cells with fluorescent dyes allows protein uptake and intracellular trafficking to be tracked and also enables physiological parameters to be measured optically. Through the conjugation of potent cytotoxicants to antibodies, novel anti-cancer drugs with improved efficacy and reduced side effects may be obtained. In this Perspective, we highlight the most exciting current and future applications of chemical site-selective protein modification and consider which hurdles still need to be overcome for more widespread use.We thank FCT Portugal (FCT Investigator to G.J.L.B.), the EU (Marie-Curie CIG to G.J.L.B. and Marie-Curie IEF to O.B.) and the EPSRC for funding. G.J.L.B. is a Royal Society University Research Fellow.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nchem.239

PEG−peptide conjugates

The remarkable diversity of the self-assembly behavior of PEG−peptides is reviewed, including self-assemblies formed by PEG−peptides with β-sheet and α-helical (coiled-coil) peptide sequences. The modes of self-assembly in solution and in the solid state are discussed. Additionally, applications in bionanotechnology and synthetic materials science are summarized

Polymerization-Induced Self-Assembly of Block Copolymer Nano-objects via RAFT Aqueous Dispersion Polymerization

In this Perspective, we discuss the recent development of polymerization-induced self-assembly mediated by reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization. This approach has quickly become a powerful and versatile technique for the synthesis of a wide range of bespoke organic diblock copolymer nano-objects of controllable size, morphology, and surface functionality. Given its potential scalability, such environmentally-friendly formulations are expected to offer many potential applications, such as novel Pickering emulsifiers, efficient microencapsulation vehicles, and sterilizable thermo-responsive hydrogels for the cost-effective long-term storage of mammalian cells

A biosignal detection and analysis patient monitoring system with data mining capabilities

The state of Philippine health informatics is primitive and outdated. Most hospitals, especially public and rural ones, suffer from the backlogs and inconvenience of the old pen and paper method of patient monitoring. Not only that, these hospitals still utilize bulky and complicated monitoring devices. A low-cost and efficient way to address this and to also further enhance the monitoring of the patient is to introduce a digital database and a medical appearance that can read biosignals and send data wirelessly. This paper address that problem by constructing a compact medical device, capable of monitoring several biosignals as well as patient database to aid in the logging and tracking of patient status. The device sends data via wifi to a website which logs and charts the data with little to no delay depending on the strength and quality of the wifi signal. The data gathered can be then be exported and analysis via a data mining software which can help relate the data in a clear manner. Upon testing and comparing the device with other consumer grade sensors, the results showed that the sensors the device used is on par with commercial devices. Wifi dependability was also tested and showed that the delay of data transmission is proportional to the strength of the signal, therefore before using the device it is recommended to secure a dependable wifi connection. With regards to the data mining aspect, it was able to show and relate the values, but it is important to note that the analysis of the software must not be taken as the final diagnosis. The device achieved all set objectives yet it still has room to improve especially with rate of advancement that technology is experiencing

An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

Over the course of more than 10 years in operation, the calibration parameters of the outboard fluxgate magnetometer (FGM) sensors on the four Cluster spacecraft are shown to be remarkably stable. The parameters are refined on the ground during the rigorous FGM calibration process performed for the Cluster Active Archive (CAA). Fluctuations in some parameters show some correlation with trends in the sensor temperature (orbit position). The parameters, particularly the offsets, of the spacecraft 1 (C1) sensor have undergone more long-term drift than those of the other spacecraft (C2, C3 and C4) sensors. Some potentially anomalous calibration parameters have been identified and will require further investigation in future. However, the observed long-term stability demonstrated in this initial study gives confidence in the accuracy of the Cluster magnetic field data. For the most sensitive ranges of the FGM instrument, the offset drift is typically 0.2 nT per year in each sensor on C1 and negligible on C2, C3 and C4

An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

Over the course of more than 10 years in operation, the calibration parameters of the outboard fluxgate magnetometer (FGM) sensors on the four Cluster spacecraft are shown to be remarkably stable. The parameters are refined on the ground during the rigorous FGM calibration process performed for the Cluster Active Archive (CAA). Fluctuations in some parameters show some correlation with trends in the sensor temperature (orbit position). The parameters, particularly the offsets, of the spacecraft 1 (C1) sensor have undergone more long-term drift than those of the other spacecraft (C2, C3 and C4) sensors. Some potentially anomalous calibration parameters have been identified and will require further investigation in future. However, the observed long-term stability demonstrated in this initial study gives confidence in the accuracy of the Cluster magnetic field data. For the most sensitive ranges of the FGM instrument, the offset drift is typically 0.2 nT per year in each sensor on C1 and negligible on C2, C3 and C4

Biosignal detection and analysis with data mining capabilities: A wireless patient monitoring device

© 2017 IEEE. In the Philippines, medical informatics had been loosely practiced in the country as early in the 1980s. Most hospitals in the country, especially public and rural ones, suffer from the backlogs and inconvenience of the traditional method of patient monitoring. Not only that, these hospitals still utilize bulky and complicated monitoring devices. A low-cost and efficient way to address this and to also further enhance the monitoring of the patient is to introduce a digital database and a medical apparatus that can read biosignals and send data wirelessly. This paper address that problem by developing a compact medical device, capable of monitoring several biosignals as well as a patient database to aid in the logging and tracking of patient status. The device sends data via WiFi to a website which logs and charts the data with little to no delay depending on the strength and quality of the signal. The data gathered can then be exported and analysis via a data mining software which can help relate the data in a clear manner

Biosignal detection and analysis with data mining capabilities: A wireless patient monitoring device

In the Philippines, medical informatics had been loosely practiced in the country as early in the 1980s. Most hospitals in the country, especially public and rural ones, suffer from the backlogs and inconvenience of the traditional method of patient monitoring. Not only that, these hospitals still utilize bulky and complicated monitoring devices. A low-cost and efficient way to address this and to also further enhance the monitoring of the patient is to introduce a digital database and a medical apparatus that can read biosignals and send data wirelessly. This paper address that problem by developing a compact medical device, capable of monitoring several biosignals as well as a patient database to aid in the logging and tracking of patient status. The device sends data via WiFi to a website which logs and charts the data with little to no delay depending on the strength and quality of the signal. The data gathered can then be exported and analysis via a data mining software which can help relate the data in a clear manner. © 2017 IEEE