Abstract

Hybrid Implants Based on Calcium-Magnesium Silicate Ceramics Diopside as a Carrier of Recombinant BMP-2 and Demineralized Bone Matrix as a Scaffold: Dynamics of Reparative Osteogenesis in a Mouse Craniotomy Model

Anna Karyagina^1,2,3,a, Polina Orlova¹, Maria Poponova¹, Inna Bulygina^1,4, Rajan Choudhary^5,6, Anna Zhulina¹, Tatyana Grunina^1,3, Kirill Nikitin¹, Natalia Strukova¹, Maria Generalova¹, Anna Ryazanova¹, Polina Kovaleva⁴, Anna Zimina⁴, Ekaterina Lukinova⁴, Egor Plakhotniuk⁴, Mariya Kirsanova⁷, Evgeniy Kolesnikov⁴, Elena Zakharova⁴, Vasily Manskikh², Fedor Senatov^1,4, and Alexander Gromov^1,b

¹Gamaleya National Research Center of Epidemiology and Microbiology, Ministry of Healthcare of the Russian Federation, 123098 Moscow, Russia

²Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia

³All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia

⁴National University of Science and Technology “MISIS”, 119049 Moscow, Russia

⁵Riga Technical University, LV-1007 Riga, Latvia

⁶Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, LV-1048 Riga, Latvia

⁷Skolkovo Institute of Science and Technology, 121205 Moscow, Russia

^* To whom correspondence should be addressed.

Received July 5, 2022; Revised August 30, 2022; Accepted September 9, 2022
Calcium-magnesium silicate ceramics, diopside, is a promising material for use in bone plastics, but until now the possibility of its use as a carrier of recombinant bone morphogenetic protein-2 (BMP-2) has not been studied, as well as the features of reparative osteogenesis mediated by the materials based on diopside with BMP-2. Powder of calcium-magnesium silicate ceramics was obtained by solid-state synthesis using biowaste – rice husks and egg shells – as source components. Main phase of the obtained ceramics was diopside. The obtained particles were irregularly shaped with an average size of about 2.3 μm and ~20% porosity; average pore size was about 24 nm, which allowed the material to be classified as mesoporous. Diopside powder adsorbs more than 150 μg of recombinant BMP-2 per milligram, which exceeds binding capacity of hydroxyapatite, a calcium-phosphate ceramic often used in hybrid implants, by more than 3 times. In vitro release kinetics of BMP-2 was characterized by a burst release in the first 2 days and a sustained release of approximately 0.4 to 0.5% of the loaded protein over the following 7 days. In vivo experiments were performed with a mouse model of cranial defects of critical size with implantation of a suspension of diopside powder with/without BMP-2 in hyaluronic acid incorporated into the disks of demineralized bone matrix with 73-90% volume porosity and macropore size from 50 to 650 μm. Dynamics of neoosteogenesis and bone tissue remodeling was investigated histologically at the time points of 12, 21, 48, and 63 days. Diopside particles were evenly spread in the matrix and caused minimal foreign body reaction. In the presence of BMP-2 by the day 63 significant foci of newly formed bone tissue were formed in the implant pores with bone marrow areas, moreover, large areas of demineralized bone matrix in the implant center and maternal bone at the edges were involved in the remodeling. Diopside could be considered as a promising material for introduction into hybrid implants as an effective carrier of BMP-2.
KEY WORDS: diopside, calcium-magnesium silicate ceramics, implant, BMP-2, demineralized bone matrix, cranial defects, bone tissue regeneration
DOI: 10.1134/S0006297922110074