Valorisation of baryte tailings for radiation shielding in plastics and nuclear waste disposal.

Baryte (BaSO) is a critical raw material with no functional recycling since the used applications are dissipative. Significant quantities of baryte end up in tailings as a side stream from the mining industry. Baryte from a secondary raw material source was used as a filler in plastics for low duty radiation shielding and as an aggregate in radiation shielding geopolymers needed for safely storing low-radioactive waste ash.

Hydrophobization and smoothing of cellulose nanofibril films by cellulose ester coatings.

The Cellulose nanofibrils (CNF), also referred to as nanocellulose, is one of the most studied bio-based material in recent year, which has good potential in the future for packaging applications due to its excellent mechanical strength and oxygen barrier properties. In the future, CNF films may also find new applications for example in printed electronics, if the surface smoothness of CNF films can be improved. One way to improve surface smoothness is to use thin coating solutions with zero porosity, such as molar mass controlled cellulose ester coatings.

Electrically Stimulated Adipose Stem Cells on Polypyrrole-Coated Scaffolds for Smooth Muscle Tissue Engineering.

We investigated the use of polypyrrole (PPy)-coated polymer scaffolds and electrical stimulation (ES) to differentiate adipose stem cells (ASCs) towards smooth muscle cells (SMCs). Since tissue engineering lacks robust and reusable 3D ES devices we developed a device that can deliver ES in a reliable, repeatable, and cost-efficient way in a 3D environment. Long pulse (1 ms) or short pulse (0.

Polypyrrole coating on poly-(lactide/glycolide)-β-tricalcium phosphate screws enhances new bone formation in rabbits.

Polypyrrole (PPy) has gained interest as an implant material due to its multifunctional properties and its high compatibility with several cell and tissue types. For the first time, the biocompatibility and osteointegration of PPy coating, incorporated with chondroitin sulfate (CS), were studied in vivo by implanting PPy-coated bioabsorbable bone fixation composite screws of poly-(lactide/glycolide) copolymer (PLGA) and β-tricalcium phosphate (TCP) into New Zealand white rabbits. Uncoated bioabsorbable polymer composite screws and commercially available stainless steel cortical screws were used as reference implants.

Encapsulation of 3-iodo-2-propynyl N-butylcarbamate (IPBC) in polystyrene-polycaprolactone (PS/PCL) blends.

Polystyrene (PS, 1), polycaprolactone homopolymers (PCL, 2) and 3-Iodo-2-propynyl n-butylcarbamate (IPBC, 3) were physically mixed in dichloromethane (DCM) and processed into solid microspheres by using emulsion solvent evaporation method. Five different compositions with varying PS/PCL ratio were tested. The phase morphology of the microspheres was studied using Phase imaging atomic force microscopy (AFM) of polished cross-sections.

Comparison of chondroitin sulfate and hyaluronic Acid doped conductive polypyrrole films for adipose stem cells.

Polypyrrole (PPy) is a conductive polymer that has aroused interest due to its biocompatibility with several cell types and high tailorability as an electroconductive scaffold coating. This study compares the effect of hyaluronic acid (HA) and chondroitin sulfate (CS) doped PPy films on human adipose stem cells (hASCs) under electrical stimulation. The PPy films were synthetized electrochemically.

Surface properties and interaction forces of biopolymer-doped conductive polypyrrole surfaces by atomic force microscopy.

Surface properties and electrical charges are critical factors elucidating cell interactions on biomaterial surfaces. The surface potential distribution and the nanoscopic and microscopic surface elasticity of organic polypyrrole-hyaluronic acid (PPy-HA) were studied by atomic force microscopy (AFM) in a fluid environment in order to explain the observed enhancement in the attachment of human adipose stem cells on positively charged PPy-HA films. The electrostatic force between the AFM tip and a charged PPy-HA surface, the tip-sample adhesion force, and elastic moduli were estimated from the AFM force curves, and the data were fitted to electrostatic double-layer and elastic contact models.

Novel polypyrrole-coated polylactide scaffolds enhance adipose stem cell proliferation and early osteogenic differentiation.

An electrically conductive polypyrrole (PPy) doped with a bioactive agent is an emerging functional biomaterial for tissue engineering. We therefore used chondroitin sulfate (CS)-doped PPy coating to modify initially electrically insulating polylactide resulting in novel osteogenic scaffolds. In situ chemical oxidative polymerization was used to obtain electrically conductive PPy coating on poly-96L/4D-lactide (PLA) nonwoven scaffolds.

Structural and functional characteristics of chimeric avidins physically adsorbed onto functionalized polythiophene thin films.

Stabilized bioreceptor layers are of great importance in the design of novel biosensors. In earlier work, chimeric avidins enabled immobilization of biotinylated antibodies onto gold surfaces with greater stability compared to more conventional avidins (wild-type avidin and streptavidin). In the present study, the applicability of chimeric avidins as a general binding scaffold for biotinylated antibodies on spin-coated functionalized polythiophene thin films has been studied by surface plasmon resonance and atomic force microscopy.

Electroactivity and biocompatibility of polypyrrole-hyaluronic acid multi-walled carbon nanotube composite.

Electroactivity of polypyrrole hyaluronic acid, electropolymerized in the presence of oxidized carbon nanotubes (PPyHA-CNT) was studied in situ by electrochemical atomic force microscopy (EC-AFM) in physiological electrolyte solution. In situ Raman spectroscopic and quartz crystal microbalance (QCM) studies were conducted on layers of the polymer grown on AT-cut 5 MHz quartz crystals. Human adipose stem cell (ASC) attachment and viability were studied by Live/Dead staining, and the proliferation was evaluated by WST-1 Cell proliferation assay for polypyrrole samples electropolymerized on titanium.