Characterization of osteogenic cells grown over modified graphene-oxide-biostable polymers.

Graphene is an excellent filler for the development of reinforced composites. This study evaluated bone cement composites of graphene oxide (GO) and poly(methyl methacrylate) (PMMA) based on the proliferation of human bone marrow mesenchymal stem cells (hBMSCs), and the anabolic and catabolic effects of the incorporation of GO on osteoblast cells at a genetic level. Surface wettability and roughness were also evaluated at different GO concentrations (GO1: 0.024 wt% and GO2: 0.048 wt%) in the polymer matrix. Fabricated specimens were tested to (a) observe cell proliferation and (b) identify the effectiveness of GO on the expression of bone morphogenic proteins. Early osteogenesis was observed based on the activity of alkaline phosphatase and the genetic expression of the run-related transcription factor 2. Moreover, bone strengthening was determined by examining the collagen type 1 alpha-1 gene. The surface roughness of the substrate material increased following the addition of GO fillers to the resin matrix. It was found that over a period of ten days, the proliferation of hBMSCs on GO2 was significantly higher compared to the control and GO1. Additionally, quantitative colorimetric mineralization of the extracellular matrix revealed greater calcium phosphate deposition by osteoblasts in GO2. Furthermore, alizarin red staining analysis at day 14 identified the presence of mineralization in the form of dark pigmentation in the central region of GO2. The modified GO-PMMA composite seems to be promising as a bone cement type for the enhancement of the biological activity of bone tissue.

Surface wettability and nano roughness at different grit blasting operational pressures and their effects on resin cement to zirconia adhesion.

This study analyzed the effect of grit blasting pressures on resin cement to zirconia (ZrO2) adhesion using enclosed mold shear bond test (EM-SBS). ZrO2 blanks were pre-treated with Rocatec™ Soft as follows: group 1: control, group 2: specimens treated at 80 kPa, group 3: at 180 kPa, group 4: at 280 kPa, and group 5: at 380 kPa. Monobond® N and Multilink® Speed were used as the silane and resin cement, respectively. Next, the blanks were assigned into three sub-groups (n=8, N=108) according to storage conditions. A non-linear relation was observed between EM-SBS and contact angle versus grit blasting pressure (r=-0.542, p=0.01). According to ANOVA (p<0.05), the EM-SBS values with both 180 kPa (17.4±6.7 MPa) and 280 kPa (19.4±4.8 MPa) were statistically higher after 12,000 thermo-cycles. Relatively equal thermo-cycled bond strength might also be achieved with intermediate (180 kPa) grit blasting pressure instead of the recommended 280 kPa.

Body Mass Index and Segmental Mass Correlation With Elastographic Strain Ratios of the Quadriceps Tendon.

OBJECTIVES: The aim of this study was to establish a relationship between quadriceps tendon stiffness and its properties and variations in the body mass index (BMI) and segmental mass. METHODS: This study was conducted in 3 groups according to their BMI (A, low [<18.5 kg/m2 ]; B, normal [18.5-25.0 kg/m2 ]; and C, high [>25.0 kg/m2 ]). All of the participants included had a sedentary lifestyle and did not do any weightlifting or any kind of sports activity in the previous 6 months. Ultrasound measurements were performed on the participants' lower right extremities, since it was the dominant side for all of the participants. RESULTS: A total of 40 healthy untrained men participated in the study. The mean age of the participants ± SD was 22.1 ± 1.3 years; the age ranges for groups A (n = 6), B (n = 18), and C (n = 16) were 19-23, 19-25, and 20-25 years, respectively; 28 of the participants were nonsmokers, and 12 of were smokers. A strong statistical difference (all P < .05) was witnessed for most of the parameters (BMI, body fat mass, dominant leg body fat content, fat-free mass index, tendon thickness, and strain ratio) among the groups. CONCLUSIONS: The length of the tendon did not show a significant increase with an increase in the BMI, body fat mass, dominant leg body fat content, and fat-free mass index. However, a greater intensification was observed for the thickness of the tendon with a significant increase in tendon stiffness (with the use of external reference material).

Impact of network aided platforms as educational tools on academic performance and attitude of pharmacology students.

OBJECTIVE: This cross-sectional study aimed to examine the impact of learning management system and WhatsApp application as educational tools on students' academic achievement and attitude. METHODS: The sample population was the students of six medical colleges of Riyadh, Saudi Arabia attending Medical Pharmacology's semester course in Bachelor of Medicine, Bachelor of Surgery (MBBS) program from September 2016 to January 2017. An exploratory approach was adopted based on a comparison between students exposed to only in-class lectures (Group-N), in-class lectures together with WhatsApp platform to disseminate the lecture slides (Group-W) and students group with in-class lectures facility blended with Learning Management System (LMS) and WhatsApp platform (Group-WL). The students' grades were assessed using unified multiple choice questions at the end of the semester. Data were analyzed using descriptive statistics and Pearson correlation (p<0.01). RESULTS: Using learning management system (LMS) and/or WhatsApp messenger tool showed a significant positive correlation in improving students' grades. Additionally, use of WhatsApp enhances students' in-class attendance though statistically insignificant. CONCLUSION: The results are pivotal for a paradigm shift of in-class lectures and discussion to mobile learning (M-learning). M-learning through WhatsApp may be as an alternative, innovative, and collaborative tool in achieving the required goals in medical education.

Chondroprotective effect of zinc oxide nanoparticles in conjunction with hypoxia on bovine cartilage-matrix synthesis.

Articular cartilage is a tissue specifically adapted to a specific niche with a low oxygen tension (hypoxia), and the presence of such conditions is a key factor in regulating growth and survival of chondrocytes. Zinc deficiency has been linked to cartilage-related disease, and presence of Zinc is known to provide antibacterial benefits, which makes its inclusion attractive in an in vitro system to reduce infection. Inclusion of 1% zinc oxide nanoparticles (ZnONP) in poly octanediol citrate (POC) polymer cultured in hypoxia has not been well determined. In this study we investigated the effects of ZnONP on chondrocyte proliferation and matrix synthesis cultured under normoxia (21% O2 ) and hypoxia (5% O2 ). We report an upregulation of chondrocyte proliferation and sulfated glycosaminoglycan (S-GAG) in hypoxic culture. Results demonstrate a synergistic effect of oxygen concentration and 1% ZnONP in up-regulation of anabolic gene expression (Type II collagen and aggrecan), and a down regulation of catabolic (MMP-13) gene expression. Furthermore, production of transcription factor hypoxia-inducible factor 1A (HIF-1A) in response to hypoxic condition to regulate chondrocyte survival under hypoxia is not affected by the presence of 1% ZnONP. Presence of 1% ZnONP appears to act to preserve homeostasis of cartilage in its hypoxic environment.

Significance of herbal medicine in removing excessive iron content in human.

Heavy metals in cigarette tobacco such as iron may cause a serious damage on human health. Surveys showed that the accumulation of certain toxic heavy metals like cadmium, mercury, iron is very often due to the effect of smoking. This work involved 15 volunteers in two randomly divided groups having the habit of cigarette smoking over 15 cigarettes / day. Concentration level of iron in blood and urine before and after treatment using the herbal medicine, widely used in Europe, is analyzed. Determination of Iron concentration in blood and urine was calculated by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) according to the procedure DIN EN ISO 11885 ("E22" from April 1998). The analysis shows that the concentration of iron in blood and urine samples in both groups increased in some volunteers instead of decrease. The independent T-test shows that the mean of iron concentration in the group A and group B had no significant difference (p>0.05). The results suggested that the herbal medicine under test does not have significant influence on reduction of iron concentration levels.