Journal of Science and Arts Year 20, No. 4(53), pp. 969-976, 2020 https://doi.org/10.46939/J.Sci.Arts-20.4-b02 Chemistry Section ORIGINAL PAPER IN VITRO CHARACTERIZATION OF HYDROXYAPATITE-BASED BIOMATERIALS, USING MESENCHYMAL STEM CELL CULTURES FROM HUMAN BONE MARROW LIVIA ELENA SIMA 1 , RENATA-MARIA VARUT 2 *, OANA GINGU 3 , GABRIELA SIMA 3 , CRISTINA TEISANU 3 , JOHNY NEAMTU 2 _________________________________________________ Manuscript received: 06.07.2020; Accepted paper: 15.10.2020; Published online: 30.12.2020. Abstract. There is considerable interest in the discovery of biomimetic materials that improve cell adhesion and reduce the time of bone integration of implants. In vitro bone cells biocompatibility was performed for the two types of biocomposites hydroxyapatite-titanium (HApTi) and hydroxyapatite-titanium with added calcium fructoborate (HApTiCaFb). In order to investigate the potential cytotoxicity of biomaterials, cell adhesion, proliferation, and osteogenic differentiation, human mesenchymal stem cells (MSCs) were used. Regarding the in vitro biocompatibility, a slight improvement in the phenotype was observed for the samples to which CaFb was added. Keywords: hydroxyapatite; calcium fructoborate; mesenchymal stem cell; human bone marrow. 1. INTRODUCTION The word "composite" refers to a heterogeneous, macroscopic combination of two or more materials (with different composition, morphology, and physical properties), being designed to produce specific physicochemical and mechanical properties. Therefore, the advantage of composites is that they have the best qualities of their constituents and often have some properties that the constituents alone do not have. Moreover, composite materials allow a flexible design, because their structure and properties can be optimized and adapted to specific applications [1-6]. Orthopedics is the medical area where the application of biomaterials is highly developed for both marketing and research purposes. The use of composites in orthopedics offers a variety of new implant designs and the ability to adapt the specific properties of the device to medical needs. Composite materials can reproduce both macroscopic and microscopic structures, as well as the most important mechanical properties of natural tissues. Composite materials are studied and tested to improve the performance and long-term stability of femoral implants and bone cement, to replace cartilage, to rebuild tendons and ligaments, and as bone grafts. Bone tissue combines a cellular component, osteocytes, and a matrix [7]. The matrix is a composite consisting of an organic portion, composed of collagen 1 Institute of Biochemistry, Romanian Academy, Bucharest 060031, Romania. 2 University of Medicine and Pharmacy, Faculty of Pharmacy, 200349 Craiova, Romania. *Corresponding Author: rennata_maria@yahoo.com. 3 University of Craiova, Faculty of Mechanics, 200512 Craiova, Romania.