Controlled-release nanotherapeutics: State of translation.

This is a review of nanotherapeutic systems, specifically those that exhibit controlled release of the encapsulated bioactive compound. The survey includes the delivery of a range of bioactive compounds, from lipophilic small molecules to hydrophilic proteins and siRNA molecules. The research into enabling sustained delivery of these compounds from nanocarriers has been prolific, but clinical success has been harder to achieve.

Modeling of drug release from bulk-degrading polymers.

This paper aims to provide a comprehensive review of the various models or simulations for predicting drug release from bulk-degrading systems. A brief description of bulk degradation processes and factors affecting the degradation rate, and consequently the release kinetics, is presented first. Next, several important classical models, often used as the basis for subsequent model development, are discussed.

Evolution of a constitutional dynamic library driven by self-organisation of a helically folded molecular strand.

Conversion of macrocyclic imine entities into helical strands was achieved through three- and four-component exchange reactions within constitutionally dynamic libraries. The generation of sequences of the intrinsic helicity codon, based on the hydrazone-pyrimidine fragment obtained by condensation of pyrimidine dialdehyde A with pyrimidine bis-hydrazine B, shifted the equilibrium between all the possible macrocycles and strands towards the full expression (>98%) of helical product [A/B]. Furthermore, it was shown that chain folding accelerated the dynamic exchange reactions among the library members.

A novel model and experimental analysis of hydrophilic and hydrophobic agent release from biodegradable polymers.

Many factors affect the rate of drug release from biodegradable polymers. Here, we focus on investigating the effect of drug type on the degradation of P(DL)LGA 53/47 films and their ultimate release profiles. A freely water-soluble drug (metoclopramide monohydrochloride) exhibited an initial burst, whereas a water-insoluble drug (paclitaxel) exhibited an initial latent period with very little drug release.

Adjustable paclitaxel release kinetics and its efficacy to inhibit smooth muscle cells proliferation.

Despite the success of drug-eluting stents in the field of interventional cardiology, very little work has been reported on the role of drug (paclitaxel) release kinetics on smooth muscle cell proliferation. This paper demonstrates how paclitaxel release from degradable polymers was successfully tailored from fast release rate to moderate and slow by changing the matrix composition. Cell counting and proliferation assays were employed to investigate the efficacy of each type of release kinetics in preventing human coronary artery smooth muscle cells proliferation.

Modeling of drug release from biodegradable polymer blends.

Numerous mathematical models that predict drug release from degradable systems have been reported. Most of these models cater only to single step, diffusion-controlled release while a few attempt to describe bi-phasic release. All these models, however, are only applicable to drug release from single (unblended) degradable polymer systems.

Paclitaxel release from single and double-layered poly(DL-lactide-co-glycolide)/poly(L-lactide) film for biodegradable coronary stent application.

Our laboratory has been developing a completely biodegradable coronary stent which is made of bilayers of biodegradable polyesters. This article presents the preliminary work done to exploit the drug delivery potential of such a polymeric stent. An antiproliferative drug (paclitaxel) was added either only to the top layer or to both layers and the in vitro release profiles were monitored for up to 90 days.