Expressing exogenous functional odorant receptors in cultured olfactory sensory neurons

<p>Abstract</p> <p>Background</p> <p>Olfactory discrimination depends on the large numbers of odorant receptor genes and differential ligand-receptor signaling among neurons expressing different receptors. In this study, we describe an <it>in vitro </it>system that enables the expression of exogenous odorant receptors in cultured olfactory sensory neurons. Olfactory sensory neurons in the culture express characteristic signaling molecules and, therefore, provide a system to study receptor function within its intrinsic cellular environment.</p> <p>Results</p> <p>We demonstrate that cultured olfactory sensory neurons express endogenous odorant receptors. Lentiviral vector-mediated gene transfer enables successful ectopic expression of odorant receptors. We show that the ectopically expressed mouse I7 is functional in the cultured olfactory sensory neurons. When two different odorant receptors are ectopically expressed simultaneously, both receptor proteins co-localized in the same olfactory sensory neurons up to 10 days <it>in vitro</it>.</p> <p>Conclusion</p> <p>This culture technique provided an efficient method to culture olfactory sensory neurons whose morphology, molecular characteristics and maturation progression resembled those observed <it>in vivo</it>. Using this system, regulation of odorant receptor expression and its ligand specificity can be studied in its intrinsic cellular environment.</p

Interaction of CO2 laser-modified nylon with osteoblast cells in relation to wettability

It has been amply demonstrated previously that CO2 lasers hold the ability to surface modify various polymers. In addition, it has been observed that these surface enhancements can augment the biomimetic nature of the laser irradiated materials. This research has employed a CO2 laser marker to produce trench and hatch topographical patterns with peak heights of around 1 μm on the surface of nylon 6,6. The patterns generated have been analysed using white light interferometery, optical microscopy and X-ray photoelectron spectroscopy was employed to determine the surface oxygen content. Contact angle measurements were used to characterize each sample in terms of wettability. Generally, it was seen that as a result of laser processing the contact angle, surface roughness and surface oxygen content increased whilst the apparent polar and total surface energies decreased. The increase in contact angle and reduction in surface energy components was found to be on account of a mixed intermediate state wetting regime owing to the change in roughness due to the induced topographical patterns. To determine the biomimetic nature of the modified and as-received control samples each one was seeded with 2×104 cells/ml normal human osteoblast cells and observed after periods of 24 hours and 4 days using optical microscopy and SEM to determine mean cell cover densities and variations in cell morphology. In addition a haeymocytometer was used to show that the cell count for the laser patterned samples had increased by up to a factor of 1.5 compared to the as-received control sample after 4 days of incubation. Significantly, it was determined that all laser-induced patterns gave rise to better cell response in comparison to the as-received control sample studied due to increased preferential cell growth on those surfaces with increased surface roughness

Evaluation of Osteoconductive Scaffolds in the Canine Femoral Multi-Defect Model

Treatment of large segmental bone defects remains an unsolved clinical challenge, despite a wide array of existing bone graft materials. This project was designed to rapidly assess and compare promising biodegradable osteoconductive scaffolds for use in the systematic development of new bone regeneration methodologies that combine scaffolds, sources of osteogenic cells, and bioactive scaffold modifications. Promising biomaterials and scaffold fabrication methods were identified in laboratories at Rutgers, MIT, Integra Life Sciences, and Mayo Clinic. Scaffolds were fabricated from various materials, including poly(L-lactide-co-glycolide) (PLGA), poly(L-lactide-co-ɛ-caprolactone) (PLCL), tyrosine-derived polycarbonate (TyrPC), and poly(propylene fumarate) (PPF). Highly porous three-dimensional (3D) scaffolds were fabricated by 3D printing, laser stereolithography, or solvent casting followed by porogen leaching. The canine femoral multi-defect model was used to systematically compare scaffold performance and enable selection of the most promising substrate(s) on which to add cell sourcing options and bioactive surface modifications. Mineralized cancellous allograft (MCA) was used to provide a comparative reference to the current clinical standard for osteoconductive scaffolds. Percent bone volume within the defect was assessed 4 weeks after implantation using both MicroCT and limited histomorphometry. Bone formed at the periphery of all scaffolds with varying levels of radial ingrowth. MCA produced a rapid and advanced stage of bone formation and remodeling throughout the defect in 4 weeks, greatly exceeding the performance of all polymer scaffolds. Two scaffold constructs, TyrPC[subscript PL]/TCP and PPF4[subscript SLA]/HA[subscript PLGA Dip], proved to be significantly better than alternative PLGA and PLCL scaffolds, justifying further development. MCA remains the current standard for osteoconductive scaffolds.United States. Army Medical Research and Materiel Command (Armed Forces Institute of Regenerative Medicine)United States. Office of Naval ResearchUnited States. Air Force. Office of the Surgeon GeneralUnited States. NavyNational Institutes of Health (U.S.)United States. Veterans AdministrationCleveland Clinic Foundatio

Overcoming Cancer Multidrug Resistance by Codelivery of Doxorubicin and Verapamil with Hydrogel Nanoparticles

The efficacy of chemotherapy is often inhibited by multidrug resistance (MDR). A highly engineerable hydrogel nanoparticle (NP) serves as a carrier for the optimal codelivery to tumor cells of the chemodrug, doxorubicin (Dox) and the chemosensitizer, verapamil (Vera), aiming at alleviating tumor MDR. The hydrogel NPs are prepared via the copolymerization of acrylamide and 2‐carboxyethyl acrylate. Dox and Vera are post‐loaded into the respective NPs, with drug loading around 7.7 wt% and 8.0 wt%, respectively. The codelivery of Dox‐NPs and Vera‐NPs increases the intracellular accumulation of Dox, and significantly enhances the cell killing ability of Dox with respect to NCI/ADR‐RES cells in vitro. These findings suggest that such codelivery nanoplatforms provide a promising route for overcoming tumor MDR. A new kind of hydrogel nanoparticles is developed as a delivery vehicle for codelivery of doxorubicin, an anti‐cancer drug (affects DNA), and verapamil, a chemosensitizer (blocks efflux pump), to tumor cells, aiming at overcoming multidrug resistance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108282/1/mabi201400035.pd

Social Skills in Preschool Children from Teachers’ Perspectives

Abstract: Preschool is one of the most important periods in a child’s life, and it can influence their social development. A lack of attention to this important life period can increase the risk of serious injuries to a child’s growth and development. The aim of this study was to examine the level of social skills in preschool children from teachers’ perspectives and investigate the relationship between social skills and the child’s environmental and cultural background. A cross-sectional study was conducted on 546 children studying in the preschool centers of Rasht city, Iran. They were selected using a multistage cluster sampling method. Data was gathered using the children’s and teachers’ demographic questionnaire and the Social Skills Rating System-Teachers (SSRS-T). Descriptive and inferential statistics were used for data analysis via SPSS software. It was found that the majority of children had moderate skills in terms of cooperation, assertion, self-control, and total social skills. Also, a statistically significant association was reported between total social skill scores and the mother’s age, mother’s education level, mother’s job, family’s income, teacher teaching experiences, and number of children in each classroom. The Iranian children were at a relatively low risk of problems with social skills. To improve children’s social skills, more attention should be paid to factors related to familial and socioeconomic status such as income, parents’ education level, maternal age, teacher’s selection for this age group, and number of children in each classroom