First research axis

Diffusion of low molecular weight compounds in polymer matrixes used in the pharmaceutical and medical field: impact on the biocompatibility and the biostability.

This research axis is divided into 3 main parts:

- The study of the polymer bulk, its extractables, the diffusion of migrants which may be additives or degradation products that are generated by sterilization processes or environment (inflammatory response , UV…)

- The surface state of the material, its evolution and adhesion phenomena occuring on it.

- The characterization of the biocompatibility

1) Study and prediction of low molecular weight compounds diffusion in the polymer

This research issue covers the following topics:

A characterization of the arrangement of polymer supramolecular structures and a characterization of low molecular weight compound structures.

Interaction studies between polymer and low molecular weight compounds

Polymer modifications and degradations because of the various treatments a medical grade polymer may undergo (sterilization, body fluid contact, drug solution interactions...)

Making a link between these previous correlations and the diffusion kinetik of low molecular weight compounds towards polymer surface.

An example

Migrations of drug compounds into polymers

Sorption is a risk factor for subdosing the drug and may reduce the therapeutic effectivness in a dramatic way.

2) Study of the material surface and on the low molecular weight blooming on it.

This research issue covers the following topics:

A study of the crystallization and polymorphism of the low molecular weight compounds; a part of them are additives added to the polymer by manufacturers (lubricants, antioxidants, stabilizers...)

A surface study characterizing the morphology, the chemical composition and the surface energy.

The impact of the surface state on protein and bacteria adhesion (in part in collaboration with other labs).

The main goal is to study and predict the biocompatibility and the bioadhesion properties of the material. Low molecular weight compounds may indeed change the surface properties and thus the interactions with the environment (pharmaceutical formulations, body fluids...). Moreover these on surface crystallized compounds have a low water solubility and may increase the risk of a particulate contamination for the patient.

In summary