Multifunctional nanoparticles for dental applications

Dental infections are very common and become dangerous if underestimated. In endodontal operations, the vitality of the tooth is often lost as the root cannot remain exposed to infections, there is a risk of bacteria spreading throughout the body. Currently, the treatments include the use of disinfectant irrigates, which are cytotoxic in the effective bactericidal concentrations. In recent years, more and more conservative approaches have been sought that allow a real regeneration of the tooth (regenerative endodontics). Several nanomedicine platforms are being explored for their ability to interact with pathogens and, at the same time, are safe for cells. The aim of this project is the development of a multifunctional platform capable of eliminating and preventing infections and, at the same time, stimulating the reconstruction of the pulp chamber. We have chosen a multifunctional antimicrobial peptide (AMP) LL37-peptide, derived from human cathelicidin (hCAMP18). The properties of LL37-peptide are amplified in the nanoformulation compared to the bare AMP in solution. With the help of LL37-AuNPs, the infection could be eliminated and the tooth could self-heal by exploiting the differentiation of SCAPs (stem cells of apical papilla). The antimicrobial capabilities of LL37-AuNPs have been tested against several bacterial strains (E. coli, S. aureus, E.faecalis S. epidermidis and E. coli ML-35p) using Broth Microdilution Antibacterial Assay in combination with plate spreading. Furthermore, the properties of the base material (gold nanoparticles) of the formulation and, therefore, the physical phenomenon of local surface plasmodic resonance (LSPR), have been exploited to increase its bactericidal effect. Interaction with stem cells was studied in vitro by: cytotoxicity test (ATP), proliferation, EGF receptor expression and odontogenic differentiation tests (ALP and Alizarin-Red Staining). To facilitate tissue regeneration, a gelatin nanofibrous electrospun support has been proposed. The results have shown promising approach to treat dental infection along with regeneration of tooth, however further study is needed.