Recent regenerative medicine is highly focused on therapies that can effectively treat intravertebral disc (IVD) degeneration. Because of its high efficiency, tissue engineering is a promising alternative therapy for cartilage defects and IVD is one of its main targets. Here we report on the fabrication of injectable electrospun microscaffolds (MS) containing a small chondrogenic agent: TD-198946.
Drug-loaded nano-/microfibers were prepared using the electrospinning technique. The therapeutic agent was incorporated directly, by solubilizing into a polymer solution to be spun. Then, fibers were structured with a picosecond laser to form thousands of 100 um in size microscaffolds. Morphology of MS was analyzed by Scanning Electron Microscopy (SEM) in order to characterize the impact of laser processing on the polymer fibers and cell morphology in contact with MS.
The main problem with drug delivery from polymeric vehicles is the initial burst release which is often unavoidable and can be controlled by many parameters e.g. temperature or pH. We performed drug release studies from both unstructured fibers mat and MS in different pH 6.4 and 7.4, which is characteristic for degenerated and normal/healthy tissue. Studies were carried out for 120 and 60 days and around 80% and 100% of the drug was released from fibers mat and MS, respectively. The differences in the release rate were also observed between various pH.
We developed a novel and straightforward method to fabricate microscaffolds from almost any type of electrospun material. PLGA-based MS containing drug molecule TD-198946 showed a controlled and gradual release profile which was slightly faster compared with unstructured material. The developed vehicle is supposed to be applied in IVD degeneration, where drug-loaded MS enhances the synthesis of glycosaminoglycans. A single administration of the material to the tissue will result in several weeks of substance release, which may have a beneficial effect on the regenerative processes of the IVD.
Acknowledgments: This work was supported by the National Centre for Research and Development grant no. LIDER/14/0053/L-9/17/NCBR/2018 and National Science Centre no. 2015/19/D/ST8/03192.
References: Nakielski et al., Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers, Small, 2021