Periodic Reporting for period 2 - PADRE (Photoactivatable Drug Releasing Implants)
Okres sprawozdawczy: 2022-11-01 do 2024-04-30
The project aims to study light-activated drug release from hydrogels that would form the core of drug-releasing implants. Hydrogels in this case are made of cellulose nanofibers which retain a large amount of water (>98% of total weight). They are well tolerated and have been previously shown to act as drug releasing matrices for long-term, sustained release.
The problem being addressed is the lack of accurate and controlled drug delivery systems. Light responsive hydrogels are of particular interests to researchers in developing accurate and controlled drug delivery systems. Light is an easy but effective and non-invasive external stimulus with great flexibility and focusability. Light responsive hydrogels are relatively easy to make by incorporating photosensitive nanocarriers into the cellulose nanofibers. Drug release can be realized through two major mechanisms: photochemical reaction (reactive oxygen species) and photothermal reaction. Both are studied in the project.
Another issue addressed is light itself. The use red or near-infrared light or the use of up-conversion to reach these biologically relevant wavelengths with deeper tissue penetration are necessary for real applications. We are also developing new approaches e.g. upconversion which allow to expand activation wavelengths of already known triggering drug release mechanisms to respond quickly and efficiently to these safer and more biocompatible wavelengths of light.
The development of light responsive hydrogels for controlled drug delivery systems can greatly improve patient compliance and convenience, optimize efficacy and safety, and improve the quality of life for patients.
The problem being addressed is the lack of accurate and controlled drug delivery systems. Light responsive hydrogels are of particular interests to researchers in developing accurate and controlled drug delivery systems. Light is an easy but effective and non-invasive external stimulus with great flexibility and focusability. Light responsive hydrogels are relatively easy to make by incorporating photosensitive nanocarriers into the cellulose nanofibers. Drug release can be realized through two major mechanisms: photochemical reaction (reactive oxygen species) and photothermal reaction. Both are studied in the project.
Another issue addressed is light itself. The use red or near-infrared light or the use of up-conversion to reach these biologically relevant wavelengths with deeper tissue penetration are necessary for real applications. We are also developing new approaches e.g. upconversion which allow to expand activation wavelengths of already known triggering drug release mechanisms to respond quickly and efficiently to these safer and more biocompatible wavelengths of light.
The development of light responsive hydrogels for controlled drug delivery systems can greatly improve patient compliance and convenience, optimize efficacy and safety, and improve the quality of life for patients.
We have been making good progress in establishing light-activated drug release from cellulose nanofiber hydrogels, which will be used as the drug releasing part of the capsule/implant. We now have demonstrated that red/NIR light-activation either through photothermal effects or photo-oxidation is able to trigger the release of molecules from the gels upon external light signal on-demand. The photo-oxidation can be enhanced by using hydrogel-binding photosensitizers instead of dyes localized in the liposomal bilayer. We have also establishing some of the building blocks for future work on hydrogel-containing implants (liposomes, and hydrogel-entrapped liposomes). Especially using photo-oxidation instead of more common photothermal effect makes the whole system easier to design and use for a larger variety of drug molecules, including larger biomolecules.
As one of the photosensitizers producing reactive oxygen species, we have use binds strongly to cellulose directly without the use of nanocarriers, we expect these systems to be useful also outside of drug delivery. Other applications could include antimicrobial surface, wound healing products etc.