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Amphiphilic phospholipid-iodinated polymer conjugates were designed and synthesized as new macromolecular probes for a highly radiopaque and biocompatible imaging technology. Bioconjugation of PEG 2000-phospholipids and iodinated polyesters by click chemistry created amphiphilic moieties with hydrophobic polyesters and hydrophilic PEG units, which allowed their self-assemblies into vesicles or spiked vesicles. More importantly, the conjugates exhibited high radiopacity and biocompatibility in in vitro X-ray and cell viability measurements. This new type of bioimaging contrast agent with a Mn value of 11 289 g mol-1 was found to have a significant X-ray signal at 3.13 mg mL-1 of iodine equivalent than baseline and no cytotoxicity after 48 hours incubation of with HEK and 3T3 cells at 20 μM (20 picomoles) concentration of conjugates per well. The potential of adopting the described macromolecular probes for bioimaging was demonstrated, which could further promote the development of a field-friendly and highly sensitive bioimaging contrast agent for point-of-care diagnostic applications.

Biodegradable magnesium-based materials have a high potential for cardiovascular stent applications; however, there exist concerns on corrosion control and biocompatibility. A surface-eroding coating of poly(1,3-trimethylene carbonate) (PTMC) on magnesium (Mg) alloy was studied, and its dynamic degradation behavior, electrochemical corrosion, hemocompatibility and histocompatibility were investigated. The PTMC coating effectively protected the corrosion of the Mg alloy in the dynamic degradation test. The corrosion current density of the PTMC-coated alloy reduced by three orders and one order of magnitude compared to bare and poly(ε-caprolactone) (PCL)-coated Mg alloy, respectively. Static and dynamic blood tests in vitro indicated that significantly fewer platelets were adherent and activated, and fewer erythrocytes attached on the PTMC-coated surface and showed less hemolysis than on the controls. The PTMC coating after 16 weeks' subcutaneous implantation in rats maintained ~55% of its original thickness and presented a homogeneously flat surface demonstrating surface erosion, in contrast to the PCL coated control, which exhibited non-uniform bulk erosion. The Mg alloy coated with PTMC showed less volume reduction and fewer corrosion products as compared to the controls after 52 weeks in vivo. Excessive inflammation, necrosis and hydrogen gas accumulation were not observed. The homogeneous surface erosion of the PTMC coating from exterior to interior (surface-eroding behavior) and its charge neutral degradation products contribute to its excellent protective performance. It is concluded that PTMC is a promising candidate for a surface-eroding coating applied to Mg-based implants., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Biomaterials, especially those based on nanomaterials, have emerged as critical tools in biomedical applications. The applications encompass a wide range such as implantable devices, tissue regeneration, drug delivery, diagnostic systems, and molecular printing. The type of materials used also covers a wide range: metals (permanent and degradable), polymers (permanent and degradable), carbon nanotubes, and lipid nanoparticles. This paper explores the use of microfluidic platforms as a high-throughput research tool for the evaluation of nanobiomaterials. Typical screening of such materials involves cell/tissue cultures to determine attributes such as cell adhesion, proliferation, differentiation, as well as biocompatibility. In addition to this, other areas such as drug delivery and toxicity can also be evaluated via microfluidics. Traditional approach for screening of such materials is very timeconsuming, and a lot of animals should be sacrificed since it involves one material and a single composition or concentration for a single test. The microfluidics approach has the advantage of using multiple types of drugs and their concentration gradients to simultaneously study the effect on the nanobiomaterial and its interaction with cell/tissue. In addition to this, microfluidics provides a unique environment to study the effect of cell-to-extracellular interaction and cell-to-cell communication in the presence of the nanobiomaterials. [ABSTRACT FROM AUTHOR]