Osteonecrosis of the jaw (ONJ) incidence has been reported as 0.004-28%, varying significantly according to the drug, dose, route of administration, and study design [1-3]. Multiple medication-related, demographic, systemic, genetic, and local risk factors are believed to cause ONJ [4-5]. Its development can be spontaneous, although invasive procedures such as tooth extraction can increase the incidence [6-7]. Medication-related osteonecrosis of the jaw (MRONJ) is characterized by progressive...
Materials & Methods
A previously validated MRONJ animal model was used . Wistar female rats (10-weeks, 180-220 g) were administered with Zoledronate (Zol) (0.1 mg/kg) for 8 weeks, to induce ONJ. At week 4, the first upper right molar was extracted and, 72 hours before this procedure, rats were medicated with PS. Since photodynamic therapy (PDT) activates PS, the animals were randomly divided into two groups to ascertain the action of PS over ONJ: group 1, animals not submitted to PDT; group 2, animals...
The easyPET.3D images, for group 1 (without PDT, rat B in Figure 1), showed a similar 18 F-FDG uptake compared to control (rat A in Figure 1), proving that PS remained inactive. For group 2 (with PDT, rat C in Figure 1), PET data showed an increase of tracer uptake, focal and unilateral matching the site of tooth extraction, therefore indicating the PS activation by the PDT. PS effect on ONJ was reflected by the higher metabolic activity of soft tissues. This study has not yet been completed,...
This pilot results, obtained with 18 F-FDG PET imaging in the selected rat model, by revealing the activation of PS with PDT, suggest that PS is a potential treatment for MRONJ. Further PET studies will be performed with 18 F-NaF to assess the effect of PS directly over bone necrosis induced by Zol.
Disclosure 1 - Holding a Position (for details click on „i“)
I. F. Castro/Managing Director/RI-TE Lda.
Disclosure 3 – Holding Property (for details click on „i“)
A. L. Silva, I. F. Castro, P. M. Correia, J. F. Veloso/co-inventors PCT/IB2016/051487 patent/RI-TE shareholders.
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