Personalized bioprinting technology for de novo PDL regeneration

ABSTRACT Avulsion of permanent teeth is one of the most serious dental injuries. The periodontal ligament (PDL) is damaged and contaminated during avulsion and the outcome after replantation of the avulsed teeth is poor. Cell-based therapy using PDL stem cells (PDLSCs) provides us with the opportunity to regenerate the PDL of avulsed teeth. Recent large animal studies have shown

promise of cell-based therapies for managing avulsed teeth. However, there is a lack of systematic design and deployment of the type of cutting-edge tissue engineering technology that would ultimately lead to development of a personalized medicine approach for the de novo PDL regeneration of avulsed teeth. Here we propose to incorporate a newly developed, two-step

technology, namely the use of Biosynspheres and personalized 3D-bioprinting for stem cell- mediated PDL regeneration. The first step involves the production of bio-ink containing PDLSCs encapsulated in microspheres, termed PDLSC-Biosynspheres. The second step employs a custom-made 3D-bioprinter designed with specific algorithms that can print a layer of PDLSC-

Biosynspheres onto the decontaminated and denuded tooth root following its natural surface topography, with a desired and uniformed thickness for PDL regeneration on the entire root surface. We hypothesize that the lost PDL on avulsed teeth can be regenerated de novo using personalized bioprinting with PDLSC-Biosynspheres. In Aim 1, we will optimize the generation of

PDLSC-Biosynspheres and characterize their biological behaviors after being printed onto the root surface in vitro and with an established SCID mouse model in vivo. In Aim 2, we will utilize a simple mini-swine model to characterize the regeneration of functional PDL in vivo. We anticipate that the combination of PDLSC-Biosynspheres and personalized 3D-bioprinting

technology will result in consistent PDL regeneration on the root, which will generate preliminary data that sets the stage for more extensive large animal studies in a future R01 application. The significant clinical impact is the potential to establish a Dental Trauma Management Center at the Tennessee Institute of Regenerative Medicine (TennIRM) for replanting avulsed teeth aiming at

successful long-term favorable outcomes. Future endeavor will include establishing stem cell banking to facilitate and secure the cell source for such medical therapies.