Binh T. T. Pham

The University of Sydney · Kolling Institute of Medical Research

Background: The skin is both a target and a potential conduit for the delivery of drugs, but its cornified cell layer resists penetration by most molecules. This study investigated the potential of superparamagnetic iron oxide nanoparticles to facilitate the transdermal delivery of anti-cancer agents. Results: Chemotherapeutic cancer drugs were app...

Therapeutic application of metallic nanoparticles such as gold nanoparticles have been extensively investigated and intriguing finding have been reported. Superparamagnetic iron oxide nanoparticles (SPION) could also potentially have therapeutic properties that can be exploited to enhance radiotherapy outcome. In this study, investigations on the d...

Nanomedicine is an emerging field with great potential in disease theranostics. We generated sterically stabilized superparamagnetic iron oxide nanoparticles (s-SPIONs) with average core diameters of 10 and 25 nm and determined the in vivo biodistribution and clearance profiles. Healthy nude mice underwent an intraperitoneal injection of these s-SP...

Physiologically stable multimodality imaging probes for positron emission tomography/single-photon emission computed tomography (PET/SPECT)-magnetic resonance imaging (MRI) were synthesized using the superparamagnetic maghemite iron oxide (γ-Fe2O3) nanoparticles (SPIONs). The SPIONs were sterically stabilized with a finely tuned mixture of diblock...

The present invention relates to a composition suitable for administration to a subject, the composition comprising pharmacologically acceptable particulate material dispersed throughout a pharmacologically acceptable liquid carrier, the particulate material being maintained in the dispersed state by a steric stabilizer, wherein the steric stabiliz...

Background The skin is both a target and a potential conduit for the delivery of drugs, but its cornified cell layer resists penetration by most molecules. This study investigated the potential of superparamagnetic iron oxide nanoparticles to facilitate the transdermal delivery of anticancer agents. Results Chemotherapeutic cancer drugs were appli...

Background This study aimed to evaluate the performance of a preclinical PET insert in three configurations: as a stand-alone unit outside the MRI bore, inside the bore of a cryogen-free 3T MRI and, finally, while performing simultaneous PET/MRI studies. Methods The PET insert consists of two rings of six detectors, each detector comprising 8 × 12...

Background: This study aimed to evaluate the performance of a preclinical PET insert in three configurations: as a standalone unit outside the MRI bore, inside the bore of a cryogen-free 3T MRI and, finally, while performing simultaneous PET/MRI studies. Methods: The PET insert consists of 2 rings of 6 detectors, each detector comprising 8x12 SiPMs...

Background: The skin is both a target and a potential conduit for the delivery of drugs, but its cornified cell layer resists penetration by most molecules. This study investigated the potential of superparamagnetic iron oxide nanoparticles to facilitate the transdermal delivery of anti-cancer agents. Results: Chemotherapeutic cancer drugs were app...

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) has been the focus in medical imaging as MRI contrast agents. SPIONs demonstrate intriguing properties that not only advantageous in diagnostic imaging but also for therapeutic application. In this study, the radiosensitization characteristic of SPIONs in electron beam radiotherapy and brachythera...

Radiosensitization effects caused by high atomic number (Z) metallic nanoparticles have been extensively explored with a wide range of x-ray based radiotherapy beams that seem to provide intriguing results for potential clinical applications. In this study, the radiobiological consequences of gold nanoparticles (AuNPs), superparamagnetic iron oxide...

RAFT‐mediated free‐radical emulsion polymerization is successfully used to synthesize polystyrene nanofibers using triblock amphiphilic macro‐RAFT copolymers as stabilizers. The polymerization is under RAFT control, producing various morphologies from spherical particles, nanofibers, nanoplatelets, and polymer vesicles. Optimum conditions are estab...

A robust polymerization technique that enables the surfactant-free aqueous synthesis of a high solid content latex containing polymeric hollow particles is presented. Uniquely designed amphiphilic macro-RAFT copolymers were used as sole stabilizers for monomer emulsification as well as free radical emulsion polymerization. The polymerization was fo...

We present the preparation of 11 nm polyacrylamide-stabilised polystyrene latex particles for conjugation to a microRNA model by surfactant-free RAFT emulsion polymerisation. Our synthetic strategy involved the preparation of amphiphilic polyacrylamide-block-polystyrene copolymers, which were able to self-assemble into polymeric micelles and 'grow'...

Sterically stabilized superparamagnetic iron oxide nanoparticles (SPIONs) were incubated with fresh human erythrocytes (red blood cells [RBCs]) to explore their potential application as magnetic resonance imaging contrast agents. The chemical shift and linewidth of ¹³³Cs⁺ resonances from inside and outside the RBCs in ¹³³Cs nuclear magnetic resonan...

A robust and simple synthesis of nano-size oblate to dumbbell shaped polymeric anisotropic particles using RAFT mediated emulsion polymerization is presented. The particle synthesis relies on the property that monomer swollen cross-linked polymer seed particles shrink and expel some of the monomer when heated. Thus, upon heating for polymerization,...

Stem cells prelabelled with iron oxide nanoparticles can be visualised using magnetic resonance imaging (MRI). This technique allows for noninvasive long-term monitoring of migration, integration and stem cell fate following transplantation into living animals. In order to determine biocompatibility, the present study investigated the biological im...

Diffusion of active cytotoxic agents throughout an entire solid tumour is a particular challenge to successful drug delivery. Here we show the simple and robust generation of non-toxic, 10–15 nm superparamagnetic iron oxide nanoparticles (SPIONs) that have been sterically stabilized by either 100% anionic or 100% cationic or 100% neutral end-functi...

In this study, a novel, robust approach is presented to produce micrometer-scale-sized polystyrene particles with narrow size distribution in highly concentrated latexes. The approach could be easily employed by those not skilled in the art to produce large quantities of polymer particles for research applications. A recent hypothesis is corroborat...

Positron annihilation lifetime spectroscopy (PALS) has been used to study the free volume in dry synthetic polymer nanoparticles of various sizes. A series of poly(styrene/divinyl benzene) particles with diameters in the range of 100 to 500 nm were synthesized and then carefully chemically treated using the sulfonation process, to increase their po...

We describe a method and conditions for the preparation of monodisperse latex particle dispersions using low molecular-weight, amphiphilic styrene-b-acrylic acid macro-RAFT diblock copolymers as sole stabilizers. The macro-RAFT copolymers are soluble in styrene monomer droplets when the acrylic acid is in its neutral, protonated form, but adsorb ir...

We have discovered a novel method for directly preparing aqueous dispersions of submicron-sized hollow particles by using an amphiphilic poly[(acrylic acid-co-butyl acrylate)-b-styrene] chain transfer agent as the stabilizer in heterogeneous reversible addition-fragmentation chain transfer (RAFT) polymerizations.[1] This method produces hollow part...

The invention provides a method of preparing an aqueous dispersion of vesiculated polymer particles, the method comprising: preparing a dispersion of polymerisable particles within a continuous aqueous phase, the polymerisable particles having a structure that is defined by an outer organic phase that comprises one or more ethylenically unsaturated...

Controlled radical polymerization using RAFT has the potential to make polymers with virtually any desired molecular architecture. For this to be implemented on an industrial scale, it must be performed by polymerization in disperse media. However, simply adding a RAFT agent to a conventional emulsion polymerization recipe leads to a loss of molecu...

A method is developed to enable emulsion polymerization to be performed under RAFT control to give living character without the problems that often affect such systems: formation of an oily layer, loss of colloidal stability, or loss of molecular weight control. Trithiocarbonate RAFT agents are used to form short stabilizing blocks from a water-sol...

Homogeneous copolymer latex particles of dodecyl methacrylate (DMA) and low-molecular-weight hydroxy-terminated polybutadiene (HTPB) oligomers were prepared by free-radical polymerization using miniemulsion methods. Rate data and latex characteristics were consistent with the classical miniemulsion mechanism where nucleation of monomer droplets is...

Latexes comprising novel copolymers were formed by second-stage emulsion polymerization of dodecyl methacrylate (DMA) onto a hydroxylated polybutadiene-based polyurethane prepolymer (PUD) as seed latex, with persulfate initiator. Morphology data from TEM imaging (including chemical fixation ultra-microtoming), glass transition temperature, dynamic...

The use of amphipathic macro reversible addition fragmentation chain transfer (RAFT) agents in miniemulsion polymerization was analyzed. The particle size of the polymer was determined by light scattering and transmission electron microscopy (TEM). The rate of polymerization was dependent on the amount of RAFT agent present. The process eliminated...

A novel technique for ab initio reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization designed to overcome problems, using the inferences from the seeded studies is presented. Such an approach developed uses an amphipathic RAFT agent and controlled feed to grow entities that form rigid micelles in the absence of monomer dr...

The kinetics of free-radical polymerisation of vinyl neo-decanoate (VneoD) and the molecular weight distributions (MWDs) of the polymers formed in the presence and absence of low molecular weight polyisoprene at 50 degreesC under a variety of conditions were investigated. The bulk reaction was successfully modelled using conventional free-radical p...

The kinetics and mechanism of the bulk free-radical polymerization of vinyl neodecanoate in the presence of polybutadiene are studied in a series of rate and molecular weight distribution measurements over the temperature range 50−90 °C. The polymerization of the vinyl ester is greatly retarded by the presence of polybutadiene. The dependences of t...

The polymerization of vinyl neo-decanoate in the presence of polybutadiene has been studied. The rate of transfer to polymer has been determined, and has been found to be very high, resulting in the formation of a highly grafted copolymer.

It is possible to create latex particles wherein the molecular architecture, on the micro- or nano-scale, appears thermodynamically unfavourable. This can be brought about by exploiting both the topology of an emulsion polymerization (i.e., it takes place in a dispersed medium) combined with appropriate free-radical chemistry. Some examples include...