Understanding drug release from PCL/gelatin electrospun blends.

Electrospinning is one of the efficient processes to fabricate polymeric fibrous scaffolds for several biomedical applications. Several studies have published to demonstrate drug release from electrospun scaffolds. Blends of natural and synthetic electrospun fibers provide excellent platform to combine mechanical and bioactive properties.

Biocompatible electrospun polymer blends for biomedical applications.

Blends of natural and synthetic polymers have received considerable attention as biomaterials due to the potential to optimize both mechanical and bioactive properties. Electrospinning of biocompatible polymers is an efficient method producing biomimetic topographies suited to various applications. In the ultimate application, electrospun scaffolds must also incorporate drug/protein delivery for effective cell growth and tissue repair.

Development of a polymeric patch impregnated with naproxen as a model of transdermal sustained release system.

This paper describes the preparation and characterization of transdermal patches impregnated with naproxen. A mixture of ethylene vinyl acetate and Eudragit E100 (80:20, w/w) is used as a polymeric matrix to obtain a thin membrane to be impregnated. Drug impregnation is carried out under pressurized CO(2) as a processing medium according to a two-step procedure.

Effects of orthopedic implants with a polycaprolactone polymer coating containing bone morphogenetic protein-2 on osseointegration in bones of sheep.

Objective: To determine elution characteristics of bone morphogenetic protein (BMP)-2 from a polycaprolactone coating applied to orthopedic implants and determine effects of this coating on osseointegration.

Animals: 6 sheep.

Procedures: An in vitro study was conducted to determine BMP-2 elution from polycaprolactone-coated implants.

Density functional approach for modeling CO2 pressurized polymer thin films in equilibrium.

We have used polymer density functional theory to analyze the equilibrium density profiles and interfacial properties of thin films of polymer in the presence of CO(2). Surface tension, surface excess adsorption of CO(2) on polymer surface, and width of the interface are discussed. We have shown the changes in these properties in the presence of CO(2) and with increasing film thickness and their inverse linear relationship with increasing chain length.

Novel dense CO2 technique for beta-galactosidase immobilization in polystyrene microchannels.

In this study we design new fabrication techniques and demonstrate the potential of using dense CO2 for facilitating crucial steps in the fabrication of polymeric lab-on-a-chip microdevices by embedding biomolecules at temperatures well below the polymer's glass transition temperature (T(g)). These new techniques are environmentally friendly and done without the use of a clean room. Carbon dioxide at 40 degrees C and between 4.

Chemotherapeutic implants via subcritical CO2 modification.

Polymer-based biomaterials have a broad range of current applications in medicine. Many implants generate a favorable biomedical outcome solely by providing short-term mechanical stability that allows healing of the surrounding tissues. An example is polymeric reconstructive resorbable plates having initial strengths sufficient to stabilize bone segments while allowing the osteosynthesis needed to restore original function following tumor resection.

Fabrication of well-defined PLGA scaffolds using novel microembossing and carbon dioxide bonding.

A novel biologically benign technique was developed to produce three-dimensional tissue engineering scaffolds with well-defined structure. Photolithography was used to design and pattern a planar scaffold skeletal structure on a photoresist (SU-8), and a variety of microembossing processes including sacrificial layer embossing and bilayer embossing were developed to transfer the skeletal pattern to the poly(DL-lactide-co-glycolide) substrate as scaffold skeletons. Subcritical carbon dioxide was then introduced to assemble these skeletons to a three-dimensional scaffold at a low temperature.

High-pressure adsorption of CO2 on NaY zeolite and model prediction of adsorption isotherms.

Supercritical carbon dioxide is an efficient solvent for adsorptive separations because it can potentially be used as both the carrier solvent for adsorption and the desorbent for regeneration. Recent results have demonstrated an anomalous peak or "hump" in the adsorption isotherm near the bulk critical point when the adsorption isotherm is plotted as a function of bulk density. This work presents new data for the adsorption and desorption of carbon dioxide in the near-critical region on a crystalline, well-structured adsorbent (NaY zeolite).