Poly (lactide-co-glycolide) nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering

Please cite this article as: Tavakoli-Darestani R, Kazemian GH, Emami M, Kamrani-Rad A. Poly (lactide-co-glycolide) nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering. Novel Biomed 2013;1:8-15.Background: A combination of polymeric nanofibrous scaffold and bioactive materials is potentially useful in bone regeneration applications.Materials and Methods: In the present study, Poly (lactide-co-glycolide) (PLGA) nanofibrous scaffolds, fabricated via electrospinning, were initially coated with Type I collagen and then with nano-hydroxyapatite. The prepared scaffolds were then characterized using SEM and their ability for bone regeneration was investigated in a rat critical size bone defect using digital mammography, multislice spiral-computed tomography (MSCT) imaging, and histological analysis.Results: Electrospun scaffolds had nanofibrous structure with homogenous distribution of n-HA on collagen-grafted PLGA. After 8 weeks of implantation, no sign of inflammation or complication was observed at the site of surgery. According to digital mammography and MSCT, PLGA nanofibers coated simultaneously with collagen and HA showed the highest regeneration in rat calvarium. In addition, no significant difference was observed in bone repair in the group which received PLGA and the untreated control. This amount was lower than that observed in the group implanted with collagen-coated PLGA. Histological studies confirmed these data and showed osteointegration to the surrounding tissue.Conclusion: Taking all together, it was demonstrated that nanofibrous structures can be used as appropriate support for tissue-engineered scaffolds, and coating them with bioactive materials will provide ideal synthetic grafts. Fabricated PLGA coated with Type I collagen and HA can be used as new bone graft substitutes in orthopaedic surgery and is capable of enhancing bone regeneration via characteristics such as osteoconductivity and osteointegratio

The latent factor structure and assessment of childbirth-related PTSD: psychometric characteristics of the City Birth Trauma Scale—Persian version (City-BiTS-P)

ObjectiveThere is no validated Persian questionnaire to measure childbirth-related PTSD (CB-PTSD) symptoms. To cover this gap, the present study aimed to provide a Persian version of the City Birth Trauma Scale (CityBiTS-Pr) and to determine its psychometric properties.MethodSince this is a cross-sectional study, sampling was done using a convenient sampling method. In total, 300 Persian-speaking women took part in this study and completed the City Birth Trauma Scale (CityBiTS-Pr), the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5), the Edinburgh Postnatal Depression Scale (EPDS), the Anxiety Subscale of the Depression, and the Anxiety and Stress Scale (DASS-21). In addition, sociodemographic information was completed. A confirmatory factor analysis of two- and four-factor models and a bi-factor model with a general factor and two specific factors were tested. Fit indices were calculated for all three models. Reliability, convergent, divergent, and discriminant validity also were examined. R v4.2.1 and SPSS v23 were used for data analysis.ResultsThe four-factor model comprised intrusion, avoidance, negative cognitions and mood, and hyper-arousal showed a poor fit. The two-factor model composed of “birth-related symptoms” and “general symptoms” provided the best results based on all fit indices. The bi-factor result was relatively good, but the loadings indicated that the general symptoms factor is not well defined.ConclusionThe Persian version of the City Birth Trauma Scale (CityBiTS-Pr) is a valid and reliable questionnaire for evaluating postpartum PTSD

Study on the behaviour of two fiddler crabs, Uca sindensis and Uca annulipes (Decapoda: Ocypodidae), in Bandar Abbas, Iran

This study was carried out on the behaviour of two species of sympatric fiddler crabs on Abi estuary, Bandar Abbas, Iran. Species differences in activity level, grooming, burrowing, muddy structure construction and feeding were all related to their habitat and food source. The more common Uca annulipes lives in low muddy areas along the edges of small streams while Uca sindensis lives in small patches on the higher areas with sandier sediment. At low tide, both species spent most of their time feeding, while at high tide they retreated into their burrows. Both species frequently walked while feeding and interacted aggressively. There were similarities in the feeding behaviour of these species: they fed at the same times of the tidal cycles, they were more likely to engage in courtship and mating behaviour during February-September and were least aggressive at this time. In both species, crabs excavated mud balls from their burrows and placed them away from their burrow entrances. There were, however, also differences between the species. Uca annulipes constructed mud hoods at the entrance to their burrows while U. sindensis did not; and the species differed in feeding rate

Online) An Open Access

ABSTRACT The purpose of this research was to impact of emotional intelligence on organizational commitment in nurses of the public hospitals of Sanandaj. This research method is descriptive-correlation. The population of this study was the nurses of the public hospitals of Sanandaj (N=320). The research sample was obtained 175 individuals according to Morgan table. To collect the information was used two standard questionnaires, namely Brad berry and Greave Emotional Intelligent Measurement Tes

Application of Pt@ZIF-8 nanocomposite-based electrochemical biosensor for sensitive diagnosis of tau protein in Alzheimer’s disease patients

Abstract Alzheimer’s disease (AD) is a progressive brain disorder characterized by the ongoing decline of brain functions. Studies have revealed the detrimental effects of hyperphosphorylated tau (p-tau) protein fibrils in AD pathogenesis, highlighting the importance of this factor in the early-stage detection of AD conditions. We designed an electrochemical immunosensor for quantitative detection of the cis conformation of the p-tau protein (cis-p-tau) employing platinum nanoparticles (Pt NPs) supported on zeolitic imidazolate frameworks (ZIF) for modifying the glassy carbon electrode (GCE) surface. Under optimum conditions, the immunosensor selectively and sensitively detected cis-p-tau within the broad linear range of 1 fg mL−1 to 10 ng mL−1 and the low limit of detection (LOD) of 1 fg mL−1 with desired reproducibility and stability. Furthermore, the fabricated immunosensor's performance was examined for the cis-p-tau analysis in the serum of AD patients, indicating its accuracy and feasibility for real-sample analysis. Notably, this is the first application of Pt@ZIF-8 nanocomposite in fabricating a valid immunosensor for selective cis-p-tau detection, even in the presence of trans-p-tau. It is worth mentioning that the enzyme-linked immunosorbent assay (ELISA) reference technique is not able to evaluate pico- or femtomolar concentrations of cis-p-tau, making the fabricated immunosensor superior for early-stage measurement and screening of AD