[EN] Inflammation processes are difficult to manage, especially in certain diseases like cancer. The prognostic of the patient may change drastically during the therapy if an inflammation process occurs. In this direction several research groups are trying to develop new agents for treatment and imaging of the inflammation process in order to improve patients prognostics. In this study we have developed and evaluated two possible imaging agents for nuclear medicine procedure using mesoporous silica nano particles as the carrier system. In this direction we developed mesoporous silica nanoparticles loaded with betamethasone and mesoporous silica nanoparticles conjugated with dexamethasone nano particles, both labeled with technetium-99m (Tc-99m) and compared the biodistribution (pharmacokinetic) profile of the two formulations in an inflammation model of carrageenan-induced pleurisy in Wistar rats. The results demonstrated that in both cases the mesoporous silica was able to show the inflammation site with a high accumulation in the inflammatory site with great renal clearance. Considering the fact that radiopharmaceuticals are considered first-order drugs the pharmacokinetics profile are the same of the biodistribution. The cytotoxicity assay demonstrated that the use of mesoporous silica nanoparticles conjugated with dexamethasone nanoparticles is safer when compared to the mesoporous silica nanoparticles loaded with betamethasone. Nevertheless, both formulations may be used for inflammation process imaging. (C) 2016 Elsevier Inc. All rights reserved. The authors would like to thank the National Scientific and Technological Research Council CHAMADA MCTI/CNPQ/CBAB No 07/2014 (CNPQ) and the Rio de Janeiro State Research Foundation (FAPERJ) for funding.Authors also gratefully acknowledge the financial support from theMinisterio de Economia y Competitividad (Project MAT2012-38429-C04-01) and the GeneralitatValenciana (project PROMETEO/2009/016) for support.