Predicting Transdermal Fentanyl Delivery Using Mechanistic Simulations for Tailored Therapy.

Transdermal drug delivery is a key technology for administering drugs. However, most devices are "one-size-fits-all", even though drug diffusion through the skin varies significantly from person-to-person. For next-generation devices, personalization for optimal drug release would benefit from an augmented insight into the drug release and percutaneous uptake kinetics.

Amino Acid and Oligopeptide Effects on Calcium Carbonate Solutions.

Biological organisms display sophisticated control of nucleation and crystallization of minerals. In order to mimic living systems, deciphering the mechanisms by which organic molecules control the formation of mineral phases from solution is a key step. We have used computer simulations to investigate the effects of the amino acids arginine, aspartic acid, and glycine on species that form in solutions of calcium carbonate (CaCO) at lower and higher levels of supersaturation.

Simulation of Calcium Phosphate Prenucleation Clusters in Aqueous Solution: Association beyond Ion Pairing.

Classical molecular dynamics simulations and free energy methods have been used to obtain a better understanding of the molecular processes occurring prior to the first nucleation event for calcium phosphate biominerals. The association constants for the formation of negatively charged complexes containing calcium and phosphate ions in aqueous solution have been computed, and these results suggest that the previously proposed calcium phosphate building unit, [Ca(HPO)], should only be present in small amounts under normal experimental conditions. However, the presence of an activation barrier for the removal of an HPO ion from this complex indicates that this species could be kinetically trapped.

Complete inclusion of bioactive molecules and particles in polydimethylsiloxane: a straightforward process under mild conditions.

By applying a slow curing process, we show that biomolecules can be incorporated via a simple process as liquid stable phases inside a polydimethylsiloxane (PDMS) matrix. The process is carried out under mild conditions with regards to temperature, pH and relative humidity, and is thus suitable for application to biological entities. Fluorescence and enzymatic activity measurements show that the biochemical properties of the proteins and enzyme tested are preserved, without loss due to adsorption at the liquid-polymer interface.

Prediction of Steam Burns Severity using Raman Spectroscopy on ex vivo Porcine Skin.

Skin burns due to accidental exposure to hot steam have often been reported to be more severe than the ones occurring from dry heat. While skin burns due to flames or radiant heat have been thoroughly characterized, the mechanisms leading to steam burns are not well understood and a conundrum still exists: can second degree burns occur without destruction of the epidermis, i.e.

Simulation of Calcium Phosphate Species in Aqueous Solution: Force Field Derivation.

A new force field has been derived for the aqueous calcium phosphate system that aims to reproduce the key thermodynamic properties of the system, including free energies of hydration of the ions and the solubility of the solid mineral phases. Interactions of three phosphate anions (PO, HPO, and HPO) with water were calibrated through comparison with the results obtained from ab initio molecular dynamics using both GGA and hybrid density functional theory with dispersion corrections. In the solid state, the force field has been evaluated by benchmarking against experiment and other existing models and is shown to reproduce the structural and mechanical properties well, despite the primary focus being on thermodynamics.