IADR Abstract Archives
Immunotherapy Based Nanotechnology: Cytokine Nanoparticles for Controlled Bone Remodeling in Orthodontics
Objectives: Pharmacological approaches to control orthodontic tooth movement (OTM) are limited due to lack of knowledge of underlying biological mechanisms and rapid flush out of drugs by blood circulation, dictating frequent injections. The current study aimed to identify pivotal molecular players in bone remodeling (BR) and OTM and develop a novel sustained release drug delivery system (DDS) based on combined immunotherapy and nanotechnology.
Methods: Gene profiling was performed by RNA-sequencing in C57BL/6 mice OTM model consisting of NiTi springs ligating maxillary first molars (M1) and incisors for 1,3,7 and 14-days. Receptor activator of NFκB-ligand (RANKL) was identified as a crucial factor in Osteoclasts (Ocs) activation during OTM. In vitro: RANKL was loaded in various unique florescent liposomes’ formulations and embedded in hydrogel (RANKLsome), to enhance its local effect. RANKLsome imaging was performed by TEM and encapsulation efficiency (EE) and release profile by ELISA. Bioactivity and cytotoxicity were evaluated in BMM cells by TRAP staining and XTT assay. In vivo: RANKLsomes, free-RANKL and saline were injected around M1. RANKL pharmacokinetics was assessed by immunofluorescence staining and liposomes by in-vivo imaging system (IVIS). 14 days after force application, OTM and femora bone changes (systemic-effect) were evaluated by μCT, Ocs by TRAP staining and Ocs gene markers (Ctsk, Acp5, Oscar) by qRT-PCR.
Results: In vitro, RANKL was efficiently encapsulated in liposomes (76%) and released up to 14 days, with neither cytotoxicity nor loss of bioactivity. In vivo, single injection of RANKLsome released RANKL for longer period than free RANKL (6 vs. 1 days, p<0.05). IVIS showed liposomes presence for up to 9 days. RANKLsome significantly accelerated OTM in comparison with free RANKL and saline groups (x2.3, x1.3, x1 respectively, p<0.05), correlating with a significant elevation in Ocs numbers and Ocs gene markers. No systemic effect was observed.
Conclusions: This is the first in-vivo report of the gene expression signature of OTM, in a time dependent manner. The discoveries were successfully implemented in developing a novel DDS which dramatically enhances local BR and accelerates OTM, through a combination of immunotherapy and nanotechnology. Further studies are needed to assess its use in humans.
Methods: Gene profiling was performed by RNA-sequencing in C57BL/6 mice OTM model consisting of NiTi springs ligating maxillary first molars (M1) and incisors for 1,3,7 and 14-days. Receptor activator of NFκB-ligand (RANKL) was identified as a crucial factor in Osteoclasts (Ocs) activation during OTM. In vitro: RANKL was loaded in various unique florescent liposomes’ formulations and embedded in hydrogel (RANKLsome), to enhance its local effect. RANKLsome imaging was performed by TEM and encapsulation efficiency (EE) and release profile by ELISA. Bioactivity and cytotoxicity were evaluated in BMM cells by TRAP staining and XTT assay. In vivo: RANKLsomes, free-RANKL and saline were injected around M1. RANKL pharmacokinetics was assessed by immunofluorescence staining and liposomes by in-vivo imaging system (IVIS). 14 days after force application, OTM and femora bone changes (systemic-effect) were evaluated by μCT, Ocs by TRAP staining and Ocs gene markers (Ctsk, Acp5, Oscar) by qRT-PCR.
Results: In vitro, RANKL was efficiently encapsulated in liposomes (76%) and released up to 14 days, with neither cytotoxicity nor loss of bioactivity. In vivo, single injection of RANKLsome released RANKL for longer period than free RANKL (6 vs. 1 days, p<0.05). IVIS showed liposomes presence for up to 9 days. RANKLsome significantly accelerated OTM in comparison with free RANKL and saline groups (x2.3, x1.3, x1 respectively, p<0.05), correlating with a significant elevation in Ocs numbers and Ocs gene markers. No systemic effect was observed.
Conclusions: This is the first in-vivo report of the gene expression signature of OTM, in a time dependent manner. The discoveries were successfully implemented in developing a novel DDS which dramatically enhances local BR and accelerates OTM, through a combination of immunotherapy and nanotechnology. Further studies are needed to assess its use in humans.