Size-dependent bond dissociation enthalpies in single-walled carbon nanotubes

We report the bond dissociation enthalpy (BDE) and the local electronic properties of Single-Walled Carbon Nanotubes (SWCNT) using density functional theory. Our analysis shows that there is a strong size-dependence of the BDE of these SWCNTs, which is inversely proportional to the radius-squared (1/r2) and the length (1/l) of SWCNT. We derive quantitative relationships from which the BDE can be calculated as a function of size and radius of the SWCNT. We find that the BDE of SWCNT outside the size-dependent region is about 480 kJ mol−1, which can be used for thermochemical calculations

A novel tissue engineered three-dimensional in vitro colorectal cancer model

The interactions of cancer cells within a solid mass with the surrounding reactive stroma are critical for growth and progression. The surrounding vasculature is recruited into the periphery of the growing tumour to supply cancer cells with nutrients and O2. This study focuses on developing a novel three-dimensional (3-D) in vitro biomimetic colorectal cancer model using colorectal cancer cells and connective tissue cells. The 3-D model comprises a dense artificial cancer mass, created by partial plastic compression of collagen type I containing HT29 colorectal cancer cells, nested in a non-dense collagen type I gel populated by fibroblasts and/or endothelial cells. HT29 cells within the dense mass proliferate slower than when cultured in a two-dimensional system. These cells form tumour spheroids which invade the surrounding matrix, away from the hypoxic conditions in the core of the construct, measured using real time O2 probes. This model is also characterized by the release of vascular endothelial growth factor (VEGF) by HT29 cells, mainly at the invading edge of the artificial cancer mass. This characterization is fundamental in establishing a reproducible, complex model that could be used to advance our understanding of cancer pathology and will facilitate therapeutic drug testing

Nanoparticle-infused-biodegradable-microneedles as drug-delivery systems: preparation and characterisation

For almost two decades, scientists were exploring the use of nanoparticles as drug vesicles capable of protecting their cargo and deliver it to the target site while evading detection by the body. However, their translation to clinical use has been slower than expected. To a large degree, this is due to the difficulty to formulate the nanomaterial into a usable form, in which they retain their unique, size-dependent properties without aggregating into a bulk material. In this work, we describe a simple methodology for synthesising novel biodegradable microneedle systems infused with silica nanoparticles (SiNP). SiNP were doped with small library of model anti-cancer drugs or drug surrogates before being characterised and encapsulated into biodegradable microneedles. Detailed preparation and characterisation methods for both the nanoparticles and the microneedles-infused with nanoparticles is presented here. We demonstrated the distribution of the nanoparticles within the microneedle matrix in a uniform, un-aggregated form, which enabled the release of the nanoparticles in a sustained manner. Formulating nanomaterial into biodegradable, hydrogel-like microneedles showed to be effective in preserving their colloidal properties, whilst simultaneously enabling the transdermal delivery of the nanomaterial into the body. Although the concepts of nanoparticles and biodegradable microneedles have been researched individually, the combination of the two, to the best of our knowledge, offers a new pathway to nanomedicine-related applications

The next level of 3D tumour models: immunocompetence

The complexity of the tumour microenvironment encompasses interactions between cancer and stromal cells. Moving from 2D cell culture methods into 3D models enables more-accurate investigation of those interactions. Current 3D cancer models focus on cancer spheroid interaction with stromal cells, such as fibroblasts. However, over recent years, the cancer immune environment has been shown to have a major role in tumour progression. This review summarises the state-of-art on immunocompetent 3D cancer models that, in addition to cancer cells, also incorporate immune cells, including monocytes, cancer-associated macrophages, dendritic cells, neutrophils and lymphocytes

Nanomedicines and microneedles: a guide to their analysis and application

The fast-advancing progress in the research of nanomedicine and microneedles application in the past two decades have suggested that the combination of the two concepts could help to overcome some of the challenges we are facing in healthcare. These include poor patient compliance with medication and the lack of appropriate administration forms that enable the optimal dose to reach the target site. Nanoparticles as drug vesicles can protect their cargo and deliver it to the target site, while evading the body’s defence mechanisms. Unfortunately, despite intense research on nanomedicine in the past 20 years, we still haven’t answered some crucial questions, e.g. about their colloidal stability in solution and their optimal formulation, which makes the translation of this exciting technology from lab bench to a viable product difficult. Dissolvable microneedles could be an effective way to maintain and stabilise nano-sized formulations, whilst enhancing the ability of nanoparticles to penetrate the stratum corneum barrier. Both concepts have been individually investigated fairly well and many analytical techniques for tracking the fate of the nanomaterial with their precious cargo, both in vitro and in vivo, have been established. Yet, to the best of our knowledge, a comprehensive overview of the analytical tools encompassing the concepts of microneedles and nanoparticles with specific and successful examples is missing. In this review, we have attempted to briefly analyse the challenges associated with nanomedicine itself but crucially, we provide an easy-to-navigate scheme of methods, suitable for characterisation and imaging the physico-chemical properties of the material matrix

Genetic variation in genes interacting with BRCA1/2 and risk of breast cancer in Cypriot population.

Inability to correctly repair DNA damage is known to play a role in the development of breast cancer. Single nucleotide polymorphisms (SNPs) of DNA repair genes have been identified, which modify the DNA repair capacity, which in turn may affect the risk of developing breast cancer. To assess whether alterations in DNA repair genes contribute to breast cancer, we genotyped 62 SNPs in 29 genes in 1,109 Cypriot women with breast cancer and 1,177 age-matched healthy controls. Five SNPs were associated with breast cancer. SNPs rs13312840 and rs769416 in the NBS1 gene were associated with a decrease in breast cancer risk (OR TT vs. TC/CC = 0.58; 95% CI, 0.37-0.92; P = 0.019 and OR GG vs. GT/TT = 0.23, 95% CI 0.06-0.85, P = 0.017, respectively). The variant allele of MRE11A rs556477 was also associated with a reduced risk of developing the disease (OR AA vs. AG/GG = 0.76; 95% CI, 0.64-0.91; P = 0.0022). MUS81 rs545500 and PBOV1 rs6927706 SNPs were associated with an increased risk of developing breast cancer (OR GG vs. GC/CC = 1.21, 95% CI, 1.02-1.45; P = 0.031; OR AA vs. AG/GG = 1.53, 95% CI, 1.07-2.18; P = 0.019, respectively). Finally, haplotype-based tests identified significant associations between specific haplotypes in MRE11A and NBS1 genes and breast cancer risk. Further large-scale studies are needed to confirm these results

Therapeutic enhancement of a cytotoxic agent using Photochemical internalisation in 3D compressed collagen constructs of ovarian cancer

Photochemical internalisation (PCI) is a method for enhancing delivery of drugs to their intracellular target sites of action. In this study we investigated the efficacy of PCI using a porphyrin photosensitiser and a cytotoxic agent on spheroid and non-spheroid compressed collagen 3D constructs of ovarian cancer versus conventional 2D culture. The therapeutic responses of two human carcinoma cell lines (SKOV3 and HEY) were compared using a range of assays including optical imaging. The treatment was shown to be effective in non-spheroid constructs of both cell lines causing a significant and synergistic reduction in cell viability measured at 48 or 96 hours post-illumination. In the larger spheroid constructs, PCI was still effective but required higher saporin and photosensitiser doses. Moreover, in contrast to the 2D and non-spheroid experiments, where comparable efficacy was found for the two cell lines, HEY spheroid constructs were found to be more susceptible to PCI and a lower dose of saporin could be used. PCI treatment was observed to induce death principally by apoptosis in the 3D constructs compared to the mostly necrotic cell death caused by PDT. At low oxygen levels (1%) both PDT and PCI were significantly less effective in the constructs

Implementing and optimizing the operation of membrane bioreactors for petroleum wastewater treatment

In the recent Kazakhstan Upstream Oil and Gas Technology and R&D Roadmap, water management has been recognized one of the fifteen main challenges that must be dealt with. This roadmap mentions that chemical processes are increasingly used for wastewater treatment; however it is recognized that "the preferred, longer term solution is likely to be membrane technology, which present a local R&D opportunity since further development is needed. This could lead to local opportunities for design, installation and maintenance of membrane separation equipment"[1]. In line with the above requirements the proposed project develops and optimizes a membrane based treatment scheme for the treating & recycling of the water within the industry. Another objective is to investigate several biological processes within the membrane bioreactor (MBR) including nitrification/denitrification and biological removal of cyanides

Implementing and optimizing the operation of membrane bioreactors for petroleum wastewater treatment

In the recent Kazakhstan Upstream Oil and Gas Technology and R&D Roadmap, water management has been recognized one of the fifteen main challenges that must be dealt with. This roadmap mentions that chemical processes are increasingly used for wastewater treatment; however it is recognized that "the preferred, longer term solution is likely to be membrane technology, which present a local R&D opportunity since further development is needed. This could lead to local opportunities for design, installation and maintenance of membrane separation equipment"[1]. In line with the above requirements the proposed project develops and optimizes a membrane based treatment scheme for the treating & recycling of the water within the industry. Another objective is to investigate several biological processes within the membrane bioreactor (MBR) including nitrification/denitrification and biological removal of cyanides