Journal of Applied Pharmaceutical Science Vol. 12(02), pp 165-171, February, 2022 Available online at http://www.japsonline.com DOI: 10.7324/JAPS.2021.120217 ISSN 2231-3354 Morphological and immunohistochemical effect of cerium dioxide nanoparticles on reparative osteogenesis of the jaw bones Ernest Bazikyan 1 , Andrey Chunikhin 1 * , Grigory Volozhin 1 , Knarik Abraamyan 1 , Vladimir Ivanov 2 , Mariya S. Zudina 3 1 Laboratory of Medical Cybernetics and Digital Biomedical Nanotechnology, Moscow State University of Medicine and Dentistry, Moscow, Russian Federation. 2 Laboratory of Nanobiomaterials and Bioeffectors for Theranostics of Socially Signifcant Diseases, Kurnakov Institute of General and Inorganic Chemistry Russian Academy of Sciences, Moscow, Russian Federation. 3 Department of Oral Surgery, Moscow State University of Medicine and Dentistry, Moscow, Russian Federation. ARTICLE INFO Received on: 07/08/2021 Accepted on: 25/10/2021 Available Online: 05/02/2022 Key words: Bone remodeling, cerium oxide nanoparticles, periodontal surgery, platelet-rich plasma. ABSTRACT Several modern scientifc studies show that nanodispersed cerium dioxide (nanoCeO 2 ) provides improved cell proliferation, including osteoblasts, antibacterial, and antiviral effects. In this study, using a comparative morphological, morphometric, and immunohistochemical analysis, we studied the possibilities of the effect of nanoCeO 2 on the processes of bone tissue remodeling after surgical interventions. NanoCeO 2 was placed in a new bioconstruction developed by us based on platelet-rich fbrin. Rabbits of the “Soviet Chinchilla” breed were injected with a new biocomposition with nanoCeO 2 on one side of the jaw into a hole formed with a trephine and with granular xenogenic osteoplastic material on the other side. The analysis of the state of the bone tissue was carried out on days 15, 25, 35, 45, and 55. The results of the morphological analysis showed that when the defects were flled with a new bioconstruction nanoCeO 2 , complete formation of bone tissue was observed, which was almost morphologically identical to the parameters of the native bone tissue. Morphometric analysis showed a high activity of the expression of matrix metalloproteinase-9 when the defects were flled with a new bioconstruction based on nanoCeO 2 at all stages of observation. INTRODUCTION The issues of bone tissue regeneration and remodeling in various pathological conditions or after surgical interventions are a complex problem of dentistry. The process of bone remodeling is mediated by numerous metabolic and immune factors. Undoubtedly, bone cellular elements, such as osteoclasts and osteoblasts, are of great importance in reparative osteogenesis (Marques et al., 2015). The study of the stimulation of reparative osteogenesis using various factors, including the use of the nanostructures of chemical elements and the creation of new materials, does not lose its relevance (Labis et al., 2016). In the early days of dental implantation, various preparations based on calcium hydroxide were used to stimulate reparative osteogenesis (Goncharov et al., 1996; Khosropanah et al., 2018). In recent years, scientifc research has been conducted in the direction of creating tissue-engineered structures using nanodispersed particles of various materials and mesenchymal stem cells and studying their effect on osteoreparative processes in jaw bones during dental implantation (Zhou et al., 2013). Unique biochemical properties have been found in nanodispersed cerium dioxide (nanoCeO 2 ). Experimental studies in vitro have shown that this material provides an improved proliferation of osteoblasts (Zhou et al., 2013). It has been previously demonstrated that CeO 2 nanoparticles have unique antioxidant (Naidi et al., 2021; Shcherbakov et al., 2015), anti- infammatory (Hirst et al., 2009; Li et al., 2020), and radioprotective effects (Popov et al., 2016a, 2016b). They also have the potential to inactivate a wide range of reactive oxygen species (Dowding et al., 2013; Shcherbakov et al., 2015; Shekunova et al., 2019; Xue et al., 2012) due to oxygen nonstoichiometry (Baranchikov et al., 2010; Zholobak et al., 2020). It has also been shown *Corresponding Authotr Andrey Chunikhin, Laboratory of Medical Cybernetics and Digital Biomedical Nanotechnology, Moscow State University of Medicine and Dentistry, Moscow, Russian Federation. E-mail: docca74 @ yandex.ru (https://creativecommons.org/licenses/by/4.0/). © 2022 Bazikyan et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License