Stent‐based tempamine delivery on neointimal formation in a porcine coronary model

Photodegradable poly(ester amide)s for indirect light-triggered release of paclitaxel

A photodegradable poly(ester amide) was developed. An amphiphilic graft copolymer derivative with paclitaxel conjugated via ester linkages formed micelles that released paclitaxel in response to UV light.

Poly(ester amide)-Poly(ethylene oxide) Graft Copolymers: Towards Micellar Drug Delivery Vehicles

Micelles formed from amphiphilic copolymers are promising materials for the delivery of drug molecules, potentially leading to enhanced biological properties and efficacy. In this work, new poly(ester amide)-poly(ethylene oxide) (PEA-PEO) graft copolymers were synthesized and their assembly into micelles in aqueous solution was investigated. It was possible to tune the sizes of the micelles by varying the PEO content of the polymers and the method of micelle preparation. Under optimized conditions, it was possible to obtain micelles with diameters less than 100 nm as measured by dynamic light scattering and transmission electron microscopy. These micelles were demonstrated to encapsulate and release a model drug, Nile Red, and were nontoxic to HeLa cells as measured by an MTT assay. Overall, the properties of these micelles suggest that they are promising new materials for drug delivery systems.

Optimization of Plasma Treatment, Manipulative Variables and Coating Composition for the Controlled Filling and Coating of a Microstructured Reservoir Stent

The object of the study was to fill and coat the microcavities of a drug eluting stent using a batch dipping process. 316L coronary stents, which were coated with a 0.25 μm layer of TiNOx were used as substrates. The stents’ surface was dimpled with 0.21 μl microcavities separated by distances of 17–28 μm depending on location. The experiment consisted of (1) optimizing the procedures to fill the microcavities with a solution of therapeutic agent and (2) covering the filled microcavities with a protective “lid” that shielded the solution during stent insertion in the arteries and then controlled its release into the surrounding tissue. The filling solution was a water-propanol mix containing 20% L-arginine. The coating solution was comprised of poly-ethylene-glycol (PEG-8000) and dexamethasone. The filling quality was investigated after altering the following variables: plasma surface activation (type of gas, pressure, power, and duration), water-propanol percentage ratio of the filling solution, lifting speed from the bath, and effect of ultrasonic vibration (monofrequency versus multifrequency). The surface coating was evaluated by altering the PEG-8000-dexamethasone percentage ratio and recording the effects on coating thickness and structure, on elution rate, and on wear resistance. The optimized process is presented in detail.