Fabricating tissues: Analysis of farming versus engineering strategies

Tissue Engineering has expanded rapidly towards target applications of tissue repair and regeneration, whilst generating surprisingly novel models to study tissue modelling. However, clinical success in producing effective engineered tissues such as bone, skin, cartilage, and tendon, have been rare and limited. Problems tend to focus on how to stimulate the replacement of initial scaffold with mechanically functional, native extracellular matrix (principally collagen). Typical approaches have been to develop perfused and mechanically active bioreactors, with the use of native collagen itself as the initial scaffold, though the idea remains that cells do the fabrication (i.e. a cultivation process). We have developed a new, engineering approach, in which the final collagen template is fabricatedwithout cell involvement. The first part of this biomimetic engineering involves a plastic compression of cellular native collagen gels to form dense, strong, collagenous neotissues (in minutes). Further steps can be used to orientate and increase collagen fibril diameter, again by non-cell dependent engineering. This allows operator control of cell or matrix density and material properties (influencing biological half life and fate). In addition, this (non-cultivation) approach can incorporate techniques to generate localised 3D structures and zones at a meso-scale. In conclusion, the use of biomimetic engineering based on native collagen, rather than cell-cultivation approaches for bulk matrix fabrication, produces huge benefits. These include speed of fabrication (minutes instead of weeks and months), possibility of fine control of composition and 3D nano-micro scale structure and biomimetic complexity.     

Competing interactions in DNA assembly on graphene

We study the patterns that short strands of single-stranded DNA form on the top graphene surface of graphite. We find that the DNA assembles into two distinct patterns, small spherical particles and elongated networks. Known interaction models based on DNA-graphene binding, hydrophobic interactions, or models based on the purine/pyrimidine nature of the bases do not explain our observed crossover in pattern formation. We argue that the observed assembly behavior is caused by a crossover in the competition between base-base pi stacking and base-graphene pi stacking and we infer a critical crossover energy of 0.3-0.5 eV. The experiments therefore provide a projective measurement of the base-base interaction strength.     

Survivin as a Target for Anti-cancer Phytochemicals According to the Molecular Docking Analysis

International Journal of Peptide Research and Therapeutics - Survivin is a unique member of the inhibitor of apoptosis protein family. Research has approved Survivin’s ability to interact...     

Superelastic Hybrid CNT/Graphene Fibers for Wearable Energy Storage

The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new electromaterials and novel fabrication strategies. Herein, a novel approach is reported to develop superelastic wet‐spun hybrid carbon nanotube graphene fibers followed by electrodeposition of polyaniline to achieve a high‐performance fiber‐based supercapacitor. It is found that the specific capacitance of hybrid carbon nanotube (CNT)/graphene fiber is enhanced up to ≈39% using a graphene to CNT fiber ratio of 1:3. Fabrication of spring‐like coiled fiber coated with an elastic polymer shows an extraordinary elasticity capable of 800% strain while affording a specific capacitance of ≈138 F g^?1. The elastic rubber coating enables extreme stretchability and enabling cycles with up to 500% strain for thousands of cycles with no significant change in its performance. Multiple supercapacitors can be easily assembled in series or parallel to meet specific energy and power needs.     

Effect of anti-IgE therapy on food allergen specific T cell responses in eosinophil associated gastrointestinal disorders

Background

Objective markers of early airway inflammation in infants are not established but are of great interest in a scientific setting. Exhaled nitric oxide (FeNO) and urinary eosinophilic protein X (uEPX) are a two such interesting markers.

Objective

To investigate the feasibility of measuring FeNO and uEPX in infants and their mothers and to determine if any relations between these two variables and environmental factors can be seen in a small sample size. This was conducted as a pilot study for the ongoing Swedish Environmental Longitudinal Mother and child Asthma and allergy study (SELMA).

Methods

Consecutive infants between two and six months old and their mothers at children's health care centres were invited, and 110 mother-infant pairs participated. FeNO and uEPX were analysed in both mothers and infants. FeNO was analyzed in the mothers online by the use of the handheld Niox Mino device and in the infants offline from exhaled air sampled during tidal breathing. A 33-question multiple-choice questionnaire that dealt with symptoms of allergic disease, heredity, and housing characteristics was used.

Results

FeNO levels were reduced in infants with a history of upper respiratory symptoms during the previous two weeks (p < 0.002). There was a trend towards higher FeNO levels in infants with windowpane condensation in the home (p < 0.05). There was no association between uEPX in the infants and the other studied variables.

Conclusion

The use of uEPX as a marker of early inflammation was not supported. FeNO levels in infants were associated to windowpane condensation. Measuring FeNO by the present method may be an interesting way of evaluating early airway inflammation. In a major population study, however, the method is difficult to use, for practical reasons.     

Tissue engineering: Dentin – pulp complex regeneration approaches (A review)

Dental pulp is a highly specialized tissue that preserves teeth. It is important to maintain the capabilities of dental pulp before a pulpectomy by creating a local restoration of the dentin-pulp complex from residual dental pulp. The articles identified were selected by two reviewers based on entry and exit criteria. All relevant articles indexed in PubMed, Springer, Science Direct, and Scopus with no limitations from 1961 to 2016 were searched. Factors investigated in the selected articles included the following key words: Dentin-Pulp Complex, Regeneration, Tissue Engineering, Scaffold, Stem Cell, and Growth Factors. Of the 233 abstracts retrieved, the papers which were selected had evaluated the clinical aspects of the application of dentin-pulp regeneration. Generally, this study has introduced a new approach to provoke the regeneration of the dentin-pulp complex after a pulpectomy, so that exogenous growth factors and the scaffold are able to induce cells and blood vessels from the residual dental pulp in the tooth root canal. This study further presents a new strategy for local regeneration therapy of the dentin-pulp complex. This review summarizes the current knowledge of the potential beneficial effects derived from the interaction of dental materials with the dentin-pulp complex as well as potential future developments in this exciting field.     

GHSR DNA hypermethylation is a new epigenetic biomarker for gastric adenocarcinoma and beyond

Aberrations of DNA methylation are early events in the development of tumors. In this study, we investigated the DNA methylation status of growth hormone secretagogue receptor (GHSR), a promising pan-cancer biomarker, in gastric cancer (GC). Initially, data sets from DNA methylation and gene expression studies available at Gene Expression Omnibus (GEO) were analyzed. Confirmation was done on primary tumor specimens and adjacent normal stomach tissue samples. Both analyses showed significant hypermethylation of GHSR. For further validation, The Cancer Genome Atlas data on stomach cancer was used. A receiver operating characteristic curve analysis yielded an area under the curve value of 0.85, corroborating its usefulness as a diagnostic marker. A genome-wide comethylation analysis revealed several correlated genes. CREB1 was found to act as an upstream regulator of this gene network. Furthermore, GHSR methylation was found to be a biomarker in several other tumor entities, namely cancers of the bladder, endometrium, esophagus, head and neck, liver, thyroid, kidney, and ovary. Our findings along with previous reports on other types of cancer suggest a high potential of GHSR gene methylation as a pan-cancer biomarker, which could be considered for liquid biopsy applications.     

Synergistic Anti-Cancer Activity of the Combination of 1,25-Dihydroxyvitamin D3 and Retinoic Acid in U937 Cell Line

Background:MicroRNA is a form of non-coding RNAs that able to regulate gene expression. miR-424 is one of the members of the regulatory family, which plays an important role in the proliferation and differentiation of myeloid cells. Epigenetic changes can change the level of miR-424 under environmental factors. Therefore, the level of expression of miR-424 in U937 cells of the myeloid line was evaluated in this research under the influence of vitamin D3 (VitD3) and retinoic acid (RA).Methods:In this study, U937 cells were cultured in the presence of VitD3, and RA to evaluate cell proliferation, viability via the trypan blue exclusion test, and expression level of miR-424 by real-time PCR at specific times.Results:Cell proliferation has shown a significant decrease in the RA group versus other groups during incubation times (P < 0.05). In VitD3 group, there was a significant increase in cell proliferation after 24- and 48-hours incubation periods versus other groups. In the VitD3 and RA groups, the increase of cell proliferation caused the downregulation of miR-424. In addition, the upregulation of VitD3 group and downregulation of the RA group were significant versus the control group (P < 0.05).DiscussionWe concluded that the expression level of miR-424 was critically affected in the dose- and time-dependent of RA and VitD3 treatment in the U937 cell line. Treatment with VitD3 decreased the expression of miR-424 and RA treatment increase miR-424 expression level in physiological doses.Key Words: Cell Proliferation, Differentiation, miR-424, U937 Cells