Vasculogenic Hydrogel:A Potential Substrate for Growth Factor Localization in Multi-Structural Tissue Engineering

Introduction: While tissue engineering offers great potential, its successful application in clinics is currently hampered. The integration of engineered tissues after implantation is limited due to the lack of a vascular network. Therefore, vascularization has emerged as one of the major problems that prevent large-scale translation of the engineered tissues to the clinic. To this end, addition of pre-vascularized network into the engineered tissues during in vitro culture has been proved to enhance tissue survival after implantation. For pre-vascularized tissue engineering, the two basic strategies relies either on natural organization of endothelial cells or on the patterning of endothelial cells into desired vascular geometry using different micro-fabrication technologies. However, in the natural system there are various strong biochemical cues, e.g. growth factors, present to guide the endothelial cells organization towards a vascular tree. Due to the prolonged presence of these strong cues on the endothelial cells, the vascular structures tend to resist remodeling towards a random organization over time which provides long-term functionality to the network. Therefore, there is a need to strategically study the spatial and temporal effect of growth factors on the engineered tissues. This approach would result in a designable vascular network with long-term stability and anastomosis compatibility which could be further used in the formation of tissue building blocks for multi-structural tissue engineering. Aim: To develop vasculogenic hydrogels and evaluate their cellular compatibility by using bone marrow derived human mesenchymal stem cells in 3D culture conditions. Materials and Methods:The vasculogenic hydrogel was prepared by photopolymerization of gelatin methacrylate (GelMA) using Irgacure 2959 as photoinitiator. For cell viability (live/dead analysis) and cell adhesion (DAPI/Alexa fluor 546 Phalloidin) studies, bone marrow derived human mesenchymal stem cells (hMSCs) were used. Results and Conclusions: The physicochemical properties analysis of the synthesized GelMA and vasculogenic hydrogel confirmed the successful crosslinking of gelatin backbone with methacrylate groups by FTIR and NMR spectroscopy. The scanning electron microscope results of the vasculogenic hydrogel revealed interconnected microporous structure with average pore size of 40-80 μm. The developed vasculogenic hydrogels supported the growth of hMSCs in terms of cell viability and adhesion over a span of 7 days within the hydrogels. The cells cultured in the hydrogel showed round morphology and cellular behavior quite similar to native tissue-like growth. Future Plans: In the present study we have optimized the vasculogenic hydrogel conditions in terms of its physicochemical properties and biocompatibility. In future, the optimized results from this study will be used to synthesize vasculogenic hydrogels for patterning growth factors (growth factor mimicking peptides) within the hydrogel and study their effect on the endothelial cells and with co-cultures of endothelial cells and mesenchymal stem cells (see Scheme 1)

Correlation of admission labour admission test in low risk pregnancies with pregnancy outcome

Background: Aim of the study was to evaluate the role of NST (labour admission test) as a screening method in management of low risk pregnancies and to study the correlation of NST with fetal outcome.Methods: A prospective observational study conducted over 500 patients managed at our centre after proper evaluation. Patients were evaluated for mode of delivery and neonatal outcome.Results: The maximum number 352 of patients belonged to 20-30 years age group, 113 patients belonged to 31-35 age group. 200 patients were of 37-40 weeks gestation and 185 were of 40-41 weeks gestation. There were 125 patients in the 41-42 weeks gestational period. Among the 500 pregnant mothers who were included in the study 82.6% had Normal NST, 11.6% had suspicious and 5.8% had pathological NST. Cesarean rate was 14.4% in normal NST group, 58.62% in suspicious group and 72.41% in pathological group study. 6.77% in Normal group had meconium stained liquor at delivery whereas 29.31% in suspicious group and 37.93% in pathological group had same.Conclusions: The non-stress test is an important screening tool to identity the fetus in jeopardy in utero. This enables an appropriate timely intervention to achieve the most favorable outcome

A Study of the Remote Work-Family Balance of Female Hotel Managers

This study explores the effect of remote work engagement (RWE) and fair pay on female hotel managers’ work-family balance (WFB). Additionally, it investigates the mediating effect of their emotional exhaustion on RWE and WFB. Although several studies have been published during the COVID-19 crisis period that investigate WFB, only a few have reported on how RWE influences WFB. Therefore, this study addresses this gap. It uses structured questionnaires to collect data from 400 female hotel managers (five-star hotels). These data are analysed using structure equation modelling (SEM): Smart-PLS is applied to examine the relationship between the independent and dependent factors – ‘vigour’, ‘absorption’, ‘dedication’, ‘fairness of pay’, and ‘work-family balance’. This study finds that RWE significantly impacts female hotel managers’ WFB. Furthermore, RWE affects their emotional fatigue and has a little effect on their WFB. Additionally, RWE is not mediated by WFB, while gender pay parity influences WFB. Remote working renders female workers more absorbed in their work, thus increasing the incidence of burnout among them due to interference with their WFB. Especially in a country like India, where females play a more prominent role domestically, hotel managers must ensure that human resource practices strategically secure the effective WFB of female hotel managers, e.g. by incorporating flexible working hours, a five-day work policy, and coaching on remote work practices. These findings can assist hospitality organisations in devising effective RWE strategies that maintain female hotel managers’ WFB, ultimately ensuring positive financial implications for them

Skyrmions and magnetic bubbles in spin-orbit coupled metallic magnets

Motivated by the observation of Skyrmion-like magnetic textures in 2D itinerant ferromagnets Fe$_n$GeTe$_2$ ($n \geq3$), we develop a microscopic model combining itinerant magnetism and spin-orbit coupling on a triangular lattice. The ground state of the model in the absence of magnetic field consists of filamentary magnetic domain walls revealing a striking similarity with our magnetic force microscopy experiments on Fe$_3$GeTe$_2$. In the presence of magnetic field, these filaments were found to break into large size magnetic bubbles in our experiments. We identify uniaxial magnetic anisotropy as an important parameter in the model that interpolates between magnetic Skyrmions and ferromagnetic bubbles. Consequently, our work uncovers new topological magnetic textures that merge properties of Skyrmions and ferromagnetic bubbles

High transport spin polarization in the van der Waals ferromagnet Fe4_4GeTe2_2

The challenging task of scaling-down the size of the power saving electronic devices can be accomplished by exploiting the spin degree of freedom of the conduction electrons in van der Waals (vdW) spintronic architectures built with 2D materials. One of the key components of such a device is a near-room temperature 2D ferromagnet with good metallicity that can generate a highly spin-polarized electronic transport current. However, most of the known 2D ferromagnets have either a very low temperature ordering, poor conductivity, or low spin polarization. In this context, the Fe$_n$GeTe$_2$ (with $n\geq3$) family of ferromagnets stand out due to their near-room temperature ferromagnetism and good metallicity. We have performed spin-resolved Andreev reflection spectroscopy on Fe$_4$GeTe$_2$ ($T_{Curie} \sim$ 273 K) and demonstrated that the ferromagnet is capable of generating a very high transport spin polarization, exceeding 50$\%$. This makes Fe$_4$GeTe$_2$ a strong candidate for application in all-vdW power-saving spintronic devices.Comment: Accepted for publication in Physical Review

Phenylalanine-Rich Peptides Potently Bind ESAT6, a Virulence Determinant of Mycobacterium tuberculosis, and Concurrently Affect the Pathogen's Growth

BACKGROUND:The secretory proteins of Mycobacterium tuberculosis (M. tuberculosis) have been known to be involved in the virulence, pathogenesis as well as proliferation of the pathogen. Among this set, many proteins have been hypothesized to play a critical role at the genesis of the onset of infection, the primary site of which is invariably the human lung. METHODOLOGY/PRINCIPAL FINDINGS:During our efforts to isolate potential binding partners of key secretory proteins of M. tuberculosis from a human lung protein library, we isolated peptides that strongly bound the virulence determinant protein Esat6. All peptides were less than fifty amino acids in length and the binding was confirmed by in vivo as well as in vitro studies. Curiously, we found all three binders to be unusually rich in phenylalanine, with one of the three peptides a short fragment of the human cytochrome c oxidase-3 (Cox-3). The most accessible of the three binders, named Hcl1, was shown also to bind to the Mycobacterium smegmatis (M. smegmatis) Esat6 homologue. Expression of hcl1 in M. tuberculosis H37Rv led to considerable reduction in growth. Microarray analysis showed that Hcl1 affects a host of key cellular pathways in M. tuberculosis. In a macrophage infection model, the sets expressing hcl1 were shown to clear off M. tuberculosis in much greater numbers than those infected macrophages wherein the M. tuberculosis was not expressing the peptide. Transmission electron microscopy studies of hcl1 expressing M. tuberculosis showed prominent expulsion of cellular material into the matrix, hinting at cell wall damage. CONCLUSIONS/SIGNIFICANCE:While the debilitating effects of Hcl1 on M. tuberculosis are unrelated and not because of the peptide's binding to Esat6-as the latter is not an essential protein of M. tuberculosis-nonetheless, further studies with this peptide, as well as a closer inspection of the microarray data may shed important light on the suitability of such small phenylalanine-rich peptides as potential drug-like molecules against this pathogen

Impact of Induced Pluripotent Stem Cells in Bone Repair and Regeneration

Purpose of Review: The main objective of this article is to investigate the current trends in the use of induced pluripotent stem cells (iPSCs) for bone tissue repair and regeneration. Recent Findings: Pluripotent stem cell–based tissue engineering has extended innovative therapeutic approaches for regenerative medicine. iPSCs have shown osteogenic differentiation capabilities and would be an innovative resource of stem cells for bone tissue regenerative applications. Summary: This review recapitulates the current knowledge and recent progress regarding utilization of iPSCs for bone therapy. A review of current findings suggests that a combination of a three-dimensional scaffolding system with iPSC technology to mimic the physiological complexity of the native stem cell niche is highly favorable for bone tissue repair and regeneration

Designing vascular supportive albumen-rich composite bioink for organ 3D printing

Bioink plays a major role in 3D printing of tissues and organs. Alginate is a widely used component for bioinks but its cellular responses are limited, which limits its clinical translation. In this study, we demonstrate the printability and cellular compatibility of composite bioink consists of sodium alginate (NaAlg) and egg white, also called albumen. The experimental conditions necessary for 3D printing composite bioink were optimized by changing different concentration ratios of Albumen/NaAlg and their various physicochemical properties were studied. The structural characteristics of the 3D printed scaffold was also investigated. In vitro experiments showed that human umbilical vein endothelial cells can successfully attach to the printed scaffold and maintain high viability during the course of study. Interestingly, vascular sprouting and neovascular network formation was observed inbetween fibers within the printed scaffold. In conclusion, the results of this study demonstrate that 3D printed Albumen/NaAlg composite bioinks with favorable biological functionality hold a great potential in tissue and organ engineering