فهرست مطالب solmaz zakhireh

Bone tissue engineering require approaches to provide a suppression/promotion environment for bone growth. Scaffold biomaterials have profound regulatory effects on the functionality of mesenchymal stem cells (MSCs). In the present study, three-component bioceramic of selenium/reduced graphene oxide/hydroxyapatite (Se/RGO/HA) was developed and its performance to repair bone defects was compared to HA. The Se/RGO/HA nanocomposite scaffold was synthesized using the chemical bath technique, characterized by X-ray diffraction spectra, Field emission scanning electron microscope, Energy dispersion X-ray spectrometer, and Fourier transform infrared spectroscopy analyses. Human adipose-derived MSCs (hAD-MSCs) were used to investigate the in-vitro osteogenic properties of Se/RGO/HA scaffold. The effect of combined scaffold on cell proliferation was analyzed by MTT assay. Cell adhesion behaviors was evaluated using optical microscopy and SEM. The osteogenic properties of Se/RGO/HA scaffold was examined by the measurement of alkaline phosphatase (ALP) activity and western blotting technique. The hAD-MSCs proliferation for HA, Se/RGO/HA nanocomposite were 2±0.1 and 1.1±0.05 respectively. The Se/RGO/HA nanocomposite had cytotoxic effect of on the KHOS-240S cancer cells . Additionally, good cell attachment and osteoblast-like morphology were characterized on the designed scaffold. The ALP activity and mineralization potential of cells seeded on Se/RGO/HA were higher than those seeded on HA. The Osteocalsin protein for Se/RGO/HA and HA were 64±1 and 12±0.1 respectively. Furthermore, the expression of Osteocalcin, a bone-specific protein, was synergistically increased by incorporation of Se and RGO into HA. In conclusion, the presence of RGO inside the Se could significantly increase positive effects of HA on the osteogenic potential of hAD-MSCs.

The current study, for the first time, suggests nature-made pollen grains (PGs) of Pistacia vera L. as a potential candidate for using as scaffolding building blocks with encapsulation capability of bioactive compounds, such as bone morphogenetic protein 4 (BMP4).

A modified method using KOH (5%, 25ºC) was developed to produce nonallergic hollow pollen grains (HPGs), confirmed by energy dispersive X-ray (EDX) analysis, field emission scanning electron microscopy (FESEM), and DNA and protein staining techniques. The in-vitro study was conducted on human adipose-derived mesenchymal stem cells (hAD-MSCs) to investigate the applicability of HPGs as bone scaffolding building blocks. Cytocompability was evaluated by FESEM, MTT assay, and gene expression analysis of apoptotic markers (BAX and BCL2). The osteoconductive potential of HPGs was assessed by alkaline phosphatase (ALP) activity measurement and gene expression analysis of osteogenic markers (RUNX2 and osteocalcin).

Findings demonstrated that HPGs can be considered as biocompatible compounds increasing the metabolic activities of the cells. Further, the bioactive nature of HPGs resulted in suitable cellular adhesion properties, required for a potent scaffold. The investigation of apoptotic gene expression indicated a reduced BAX/BCL2 ratio reflecting the protective effect of HPGs on hAD-MSCs. The increased ALP activity and expression of osteogenic genes displayed the osteoconductive property of HPGs. Moreover, the incorporation of BMP4 in HPGs initiated a synergistic effect on osteoblast maturation.

Owing to the unique compositional and surface nanotopographical features of the Pistacia vera L. HPG, this microscale architecture provides a favorable microenvironment for the bottom-up remodeling of bone.

Nowadays, due to the resistance of bacteria to antibiotics and their side effects, much attention is paid to the antibacterial properties of medicinal plants. Malva sylvestis L. plays an important role in traditional medicine and herbal medicine industry. This study deals with antibacterial effects of 50, 100, 200, 400 mg/ml concentration of non-polar extract of Malva sylvestris L. on Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa bacteria by means of well diffusion method. Determination test of MIC (Minimum inhibitory concentration of bacteria growth) and MBC (Minimum bactericidal concentration) was done by tube dilution method. The results indicated that non-polar extract of Malva sylvestris L. inhibits growth of Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa bacteria. The inhibitory effect increases by increasing the extract concentration. MIC and MBC of these bacteria respectively varies from 12.5-50 mg/ml and 12.5-100 mg/ml respectively. This extract can be a good candidate for future in vivo studies for production of new antibacterial drugs.