Drug Delivery

The group develops various carrier systems (light blue cylinder, figure A) like hydrogels, inhalable microparticles or implants intented for the controlled release of pharmacologically active or diagnostic agents (deep blue spheres, Abbildung A). In particular, this includes therapeutical proteins and antibodies as well as several nanoparticulate materials. The design of these carrier systems is supposed for a controlled release over versatile, medically reasonable periods of time (sample release profil, figue B). © Universität Regensburg, Lehrstuhl für Pharmazeutische Technologie

The pharmacological properties of drug substances are the basis of an effective pharmacotherapy. Nevertheless, their physicochemical properties often impede an application using conventional dosage forms. Due to insufficient stability, low solubility or unfavorable biodistribution of drug molecules, their therapeutic efficacy can be moderate. In such cases the development of controlled release drug delivery systems can be beneficial. Within the plethora of such dosage forms, our group focuses on the design of parenteral and locally applicable systems.

Hydrogels as Drug Delivery System

Principle of Diels-Alder reaction for hydrogel formation. Furyl- and maleimide functionalized multiarmed polyethylene glycol are dissolved in water and combined. Directly after mixing both components the formation of hydrogels is initiated

Biologics have gained importance as the drug substances in recent years. As prominent representatives, proteins and nucleic acids are valuable therapeutics. However, there are still challenges that come along with their properties. Due to their size and limited stability in biological media, they can frequently not be applied via conventional routes and vehicles. An example are biologics that are used for the treatment of retinal diseases like diabetic retinopathy or wet age-related macular degeneration, where they need to be administered via local injection in the glass body in order to reach sufficient concentrations. Appropriate depot systems would increase patient compliance and reduce the risk of side effects. Hydrogels represent optimal materials for this purpose. We developed hydrogels on the basis of functionalized polyethylene glycols that form three-dimensional networks via Diels-Alder reaction (figure 5). The resulting matrices are perfectly transparent and slowly degrade in water via a retro Dies-Alder mechanism. When injected into the tissue, these materials can gel in situ and form a network that can release proteins over weeks and months.