Comparative study of the effects of different nanomaterials on the viability of human osteoblast-like cells

The aim of this study was to compare the effects of two types of nanomaterials, cobalt-exchanged hydroxyapatite (CoHAp) and calcium phosphate/poly-(DL-lactide-co-glycolide) (CP/PLGA), on the viability of Saos-2 osteoblast-like cells, using MTT test. We have examined the suspension of this materials in the following concentrations: 1.6, 8, 40, 200, 1000 and 2500 μg/ml, as well as extracts in concentration range from 2,5% to 100%. Both materials showed cytotoxic effect at higher concentrations of suspension and extract, respectively, but they were not cytotoxic at lower concentrations. CP/PLGA acted stronger cytotoxic compared to CoHAp, regardless of whether it is examined suspension or extract. CoHAp in small concentrations of suspension and extract acted slightly stimulatory on cells. This suggests that CoHAp may have advantage for use in the in vivo systems

Scanning electron microscopy study of changes in nanoparticles surface under in vitro simulated physiological conditions

In this study we observed the changes in surface of nanoparticles of two different nanomaterials, cobalt-substituted hydroxyapatite (CoHAp) and calcium phosphate/poly-(DLlactide-co-glycolide) (CP/PLGA) that occurred under simulated physiological conditions in vitro. Both nanomaterials were incubated in an appropriate volume of Dulbecco's Modified Eagle Medium (DMEM) for 3 days at 37 0C and then the medium was removed and materials were dried. Surface changes of nanoparticles were studied by scanning electron microscopy (SEM). Results of SEM analysis show that changes in the size and shape of the nanoparticles took place. These changes can be explained by interactions of nanomaterials with DMEM. In the case of CP/PLGA it was probably the result of polymer degradation and changes in CoHAp nanoparticles were probably the result of ion exchange

Examination of the influence of nanomaterials calcium phosphate/poly(DL-lactide-co-glycolide) and cobalt-exchanged hydroxyapatite on the viability of Saos-2 cells

We have examined the effect of extracts of the calcium phosphate/poly(DL-lactide-co-glycolide) (CP/PLGA) and cobalt-exchanged hydroxyapatite (CoHAp), on the viability of Saos2 osteoblastlike cells. Extracts were prepared by incubation for 3 days at 37°C in the cultivation medium. Conductivity and pH value of extracts were measured before viability assay. Cell viability was estimated by MTT test performed after 24 h incubation of cells with various concentrations of extracts. Extract of CP/PLGA acted more cytotoxic on osteoblasts than the extract of CoHAp. This difference in the effect of examined extracts can be explained by their different pH value and conductivity

Changes of HAp/PLLA biocomposites and tissue reaction after subcutaneous implantation

Experimental and clinical studies have shown that HAp granules and powder may be successfully applied in reconstruction of bone defects. Composite HAp/PLLA biomaterial embodies good characteristics of each of these biomaterials. Differences in porosity, microstructure, compressive consistency as well as in bioresorbility of HAp/PLLA are achieved by using PLLA of different mole masses. The aim of this study was to analyse light microscopy of the tissue reaction and changes of implants made of combination of syngeneic bone fragments and HAp/PLLA biocomposites with PLLA molecule mass of 430 000 (HP2) and 50 000 (HP3). The mice were divided into 4 experimental studies, 8 animals each. Two groups underwent implantation one group of mice was falsely operated, and one group was used for general control. Pathohistological analysis of implants was performed three months after subcutaneous implantation. Phagocytosis of HAp/ PLLA and bone was noticed on both implants’ preparations. Blood vessels were also noticed confirming the process of angiogenesis around the implants’ particles. The holes around particles of biocomposites and bone fragments represented the signs of their resorption. The presence of multinuclear cells between implants’ particles was observed and it was more prominent in HP3 implants. Osteogenesis is more intense in HP3 and ectopic hematopoesis is present. Our results show that designed HAp/PLLA biocomposites have good biocompatibility, their combination with bone fragments of a vital bone enables osteogenesis and hematopoesis and these processes are more prominent if PLLA biocomposite with lower molecular mass was used

Osteogenic activity in a mice subcutaneous implant of porous hydroxyapatite/poly-L-lactide loaded with bone marrow cells

Hydroxyapatite (HAp) is biomaterial widely used in the regeneration of bone tissue. Addition of osteogenic cells to HAp implants may accelerate the bone repair process. The aim of this study was to investigate how the bone marrow cells (BMCs) loading of porous hydroxyapatite/poly-L-lactide (HAp/PLLA) act to ectopic osteogenesis. In this purpose HAp/PLLA with and without BMCs was subcutaneously implanted into BALB/c mice. As a control served implants from both types which weren’t implanted. Three weeks after implantation, histological analysis of implants was done. It was observed significant resorption and induction of collagenogenesis in implanted biomaterials. The structure of new bone was seen in implants loaded with bone marrow cells

Osteogenic potential of freshly isolated cells of adiposederived mesenchymal fraction applied with nanoparticles

The aim of this study was to investigate the osteogenic potential of freshly isolated adipose tissue-derived mesenchymal stromal/stem cells (ASCs) in bone regeneration of rabbit calvaria defects. ASCs were applied together with calcium phosphate-poly-DL-lactide-co-glycolide (CPPLGA) nanoparticles that are mixed in an appropriately prepared blood clot (BC). Parallelly were analysed defects filled with fragmented adipose tissue (FAT) instead of ASCs, with CP-PLGA in BC, and only with nanoparticles. Bone density in defects was measured after I, III and VI weeks, and histological examination was done after IV and VIII weeks after filling defects. Approach to assisted osteoregeneration which is based on the use of fresh non-induced ASCs has proven to be promising due to the favorable effect on bone regeneration and simplicity of their application

The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis

The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by the two different methods, namely HPLC-UV and 1H NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = 602.10 ± 0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization, isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product

Assessment of the effects of nanoparticles of CP/PLGA on cultures of different cell lines

The aim of this study was to examine the effects of nanoparticles of calcium phosphate/poly-(DL-lactide-co-glycolide) (NPs-CP/PLGA) on viability and growth of different cell lines in vitro. HeLa and MDCK cells were incubated with different concentrations of suspension and extract of NPs-CP/PLGA. Concentrations of suspension were in the range from 1.6 μg/ml to 5000 μg/ml and extract in the range from 2.5% to 50%. After incubation, MTT test was performed. Our results indicate that examined nanomaterial shows different effects depending on type of the cells, applied concentration of nanomaterial as well as whether it is examined suspension or extract

Nanoparticles of Cobalt-Substituted Hydroxyapatite in Regeneration of Mandibular Osteoporotic Bones

Indications exist that paramagnetic calcium phosphates may be able to promote regeneration of bone faster than their regular, diamagnetic counterparts. In this study, analyzed was the influence of paramagnetic cobalt-substituted hydroxyapatite nanoparticles on osteoporotic alveolar bone regeneration in rats. Simultaneously, biocompatibility of the material was tested in vitro, on osteoblastic MC3T3-E1 and epithelial Caco-2 cells in culture. The material was shown to be biocompatible and nontoxic when added to epithelial monolayers in vitro, while it caused a substantial decrease in the cell viability as well as deformation of the cytoskeleton and cell morphology when incubated with the osteoblastic cells. In the course of six months after the implantation of the material containing different amounts of cobalt, ranging from 5 – 12 wt%, in the osteoporotic alveolar bone of the lower jaw, the following parameters were investigated: histopathological parameters, alkaline phosphatase and alveolar bone density. The best result in terms of osteoporotic bone tissue regeneration was observed for hydroxyapatite nanoparticles with the largest content of cobalt ions. The histological analysis showed a high level of reparatory ability of the nanoparticulate material implanted in the bone defect, paralleled by a corresponding increase in the alveolar bone density. The combined effect of growth factors from autologous plasma admixed to cobalt-substituted hydroxyapatite was furthermore shown to have a crucial effect on the augmented osteoporotic bone regeneration upon the implantation of the biomaterial investigated in this study

Nanoparticles of Cobalt-Substituted Hydroxyapatite in Regeneration of Mandibular Osteoporotic Bones

Indications exist that paramagnetic calcium phosphates may be able to promote regeneration of bone faster than their regular, diamagnetic counterparts. In this study, analyzed was the influence of paramagnetic cobalt-substituted hydroxyapatite nanoparticles on osteoporotic alveolar bone regeneration in rats. Simultaneously, biocompatibility of the material was tested in vitro, on osteoblastic MC3T3-E1 and epithelial Caco-2 cells in culture. The material was shown to be biocompatible and nontoxic when added to epithelial monolayers in vitro, while it caused a substantial decrease in the cell viability as well as deformation of the cytoskeleton and cell morphology when incubated with the osteoblastic cells. In the course of six months after the implantation of the material containing different amounts of cobalt, ranging from 5 – 12 wt%, in the osteoporotic alveolar bone of the lower jaw, the following parameters were investigated: histopathological parameters, alkaline phosphatase and alveolar bone density. The best result in terms of osteoporotic bone tissue regeneration was observed for hydroxyapatite nanoparticles with the largest content of cobalt ions. The histological analysis showed a high level of reparatory ability of the nanoparticulate material implanted in the bone defect, paralleled by a corresponding increase in the alveolar bone density. The combined effect of growth factors from autologous plasma admixed to cobalt-substituted hydroxyapatite was furthermore shown to have a crucial effect on the augmented osteoporotic bone regeneration upon the implantation of the biomaterial investigated in this study