The aim of the present study was to compare the osteogenic potential of mesenchymal stem cells extracted from the bone marrow (BM-MSCs) and adipose tissue (AD-MSCs) of young dogs. The following parameters were assessed: dimethyl thiazolyl diphenyl tetrazolium (MTT) conversion, alkaline phosphatase (ALP) activity, collagen and mineralised matrix synthesis, and the expressions of osterix, bone sialoprotein (BSP), and osteocalcin (OC).
1 January 2012 in Advances in Materials Science and Engineering
The biocompatibility and bioactivity properties of hydroxyapatites (HAs) modified through lithium addition were investigated. Hydroxyapatites obtained from bovine bone were mixed with lithium carbonate (Li), in the proportions of 0.25, 0.50, 1.00, and 2.00% wt, and sintered at 900°, 1000°, 1100°, 1200°, and 1300°C, creating LiHA samples. The osteoblast culture behavior was assessed in the presence of these LiHA compositions. The cellular interactions were analyzed by evaluating the viability and cellular proliferation, ALP production and collagen secretion. The cytotoxic potential was investigated through measurement of apoptosis and necrosis induction. The process of cellular attachment in the presence of the product of dissolution of LiHA, was evaluated trough fluorescence analysis. The physical characteristics of these materials and their cellular interactions were examined with SEM and EDS. The results of this study indicate that the LiHA ceramics are biocompatible and have variable bioactivities, which can be tailored by different combinations of the concentration of lithium carbonate and the sintering temperature. Our findings suggest that LiHA 0.25% wt, sintered at 1300°C, combines the necessary physical and structural qualities with favorable biocompatibility characteristics, achieving a bioactivity that seems to be adequate for use as a bone implant material.
Immune response to biomaterials, which is intimately related to their surface properties, can produce chronic inflammation and fibrosis, leading to implant failure. This study investigated the development of magnetic nanoparticles coated with silica and incorporating the anti-inflammatory drug naproxen, aimed at multifunctional biomedical applications. The synthesized nanoparticles were characterized using various techniques that confirmed the presence of magnetite and the formation of a silica-rich bioactive glass (BG) layer. In vitro studies demonstrated that the nanoparticles exhibited bioactive properties, forming an apatite surface layer when immersed in simulated body fluid, and biocompatibility with bone cells, with good viability and alkaline phosphatase activity. Naproxen, either free or encapsulated, reduced nitric oxide production, an inflammatory marker, while the BG coating alone did not show anti-inflammatory effects in this study. Overall, the magnetic nanoparticles coated with BG and naproxen showed promise for biomedical applications, especially anti-inflammatory activity in macrophages and in the bone field, due to their biocompatibility, bioactivity, and osteogenic potential.
The objective of the present study was to evaluate the effect of the ionic product (IP) of BG60S on osteoblastic activity. The following media groups were created: DMEM, which is formed by osteoblasts in basal medium; IP DMEM, which is formed by osteoblasts in IP with basal medium; OST, which is formed by osteoblasts in osteogenic medium; and IP OST, which is formed by osteoblasts in IP with osteogenic medium. The osteoblasts were cultivated in an incubator at 37 °C and 5 % CO2 for 7, 14 and 21 days. After each period, the alkaline phosphatase (AP) activity, mineralised area per field and expression of osterix (OSX), bone sialoprotein (BSP), osteonectin (ON) and osteocalcin (OC) were evaluated by reverse transcription (RT)-PCR. The IP significantly increased the AP activity in the IP DMEM group at 7 and 14 days and reduced the AP activity in the IP OST group at 14 and 21 days relative to their respective controls (DMEM and OST). The groups that received the IP displayed a significant increase in the percentage of mineralised area per field and more advance maturation of the extracellular matrix relative to those that did not receive IP. The IP significantly increased the expression of OSX, BSP and ON in osteoblast cultures maintained in IP DMEM compared with the control (DMEM) for the majority of studied periods. In osteogenic medium, IP also significantly increased OSX, BSP, ON and OC expression compared with the control (OST) for the majority of studied periods. The IP of BG60S alters the gene expression of canine osteoblasts, favouring the synthesis and mineralisation of the extracellular matrix.