Effect of Laser Irradiation on Cell Cycle and Mitosis

Introduction: In this research, low-level helium-neon (He-Ne) laser irradiation effects on monkey kidney cells (Vero cell line) mitosis were studied.Methods: The experiment was carried out on a monkey kidney cell line “Vero (CCL-81)”. This is a lineage of cells used in cell cultures and can be used for efficacy and media testing. The monolayer cells were formed on coating glass in a spectral cuvette (20×20×30 mm). The samples divided into two groups. The first groups as irradiated monolayer cells were exposed by a He-Ne laser (PolyaronNPO, L’vov, Ukraine) with λ = 632.8 nm, max power density (P) = 10 mW/cm2, generating linearly polarized and the second groups as the control monolayer cells were located in a cuvette protected by a lightproof screen from the first cuvette and also from the laser exposure. Then, changing functional activity of the monolayer cells, due to the radiation influence on some physical factors were measured.Results: The results showed that low-intensity laser irradiation in the range of visible red could make meaningful changes in the cell division process (the mitosis activity). These changes depend on the power density, exposure time, the presence of a magnetic field, and the duration of time after exposure termination. The stimulatory effects on the cell division within the power density of 1-6 mW/(cm2) and exposure time in the range of 1-10 minutes was studied. It is demonstrated that the increase in these parameters (power density and exposure time) leads to destructing the cell division process.Conclusion: The results are useful to identify the molecular mechanisms caused by low-intensity laser effects on the biological activities of the cells. Thus, this study helps to optimize medical laser technology as well as achieving information on the therapeutic effects of low-intensity lasers

Spectroscopic evaluation of QDs encapsulated with a novel biocompatible polymer for cancer diagnosis

Quantum dots (QDs) are new class of fluorescent inorganic nanocrystals which have been used for in vitro and in vivo imaging. Their unique optical properties such as broad excitation spectra, narrow emission spectrum and resistance to photobleaching make them ideal for biological labeling. Sentinel lymph node biopsy is a means of ultra-staging cancer metastasis and is now the standard of care in breast cancer surgery. Localisation of sentinel nodes is also important in the treatment of head and neck cancer. Current tracers for SLN biopsy include the blue dye have various limitations that could be overcome by quantum dots that emit in near infrared range (>700 nm). To safely deliver QDs they must be encapsulated in a biocompatible coating. In this study we encapsulate CdTe QDs with new nanocomposite material based on a silsesquioxane modified poly (carbonate-urea) urethane polymer, and evaluated their spectroscopic properties

Surface Modification of Biomaterials: A Quest for Blood Compatibility

Cardiovascular implants must resist thrombosis and intimal hyperplasia to maintain patency. These implants when in contact with blood face a challenge to oppose the natural coagulation process that becomes activated. Surface protein adsorption and their relevant 3D confirmation greatly determine the degree of blood compatibility. A great deal of research efforts are attributed towards realising such a surface, which comprise of a range of methods on surface modification. Surface modification methods can be broadly categorized as physicochemical modifications and biological modifications. These modifications aim to modulate platelet responses directly through modulation of thrombogenic proteins or by inducing antithrombogenic biomolecules that can be biofunctionalised onto surfaces or through inducing an active endothelium. Nanotechnology is recognising a great role in such surface modification of cardiovascular implants through biofunctionalisation of polymers and peptides in nanocomposites and through nanofabrication of polymers which will pave the way for finding a closer blood match through haemostasis when developing cardiovascular implants with a greater degree of patency

Clinical Potential of Quantum Dots

Advances in nanotechnology have led to the development of novel fluorescent probes called quantum dots. Quantum dots have revolutionalized the processes of tagging molecules within research settings and are improving sentinel lymph node mapping and identification in vivo studies. As the unique physical and chemical properties of these fluorescent probes are being unraveled, new potential methods of early cancer detection, rapid spread and therapeutic management, that is, photodynamic therapy are being explored. Encouraging results of optical and real time identification of sentinel lymph nodes and lymph flow using quantum dots in vivo models are emerging. Quantum dots have also superseded many of the limitations of organic fluorophores and are a promising alternative as a research tool. In this review, we examine the promising clinical potential of quantum dots, their hindrances for clinical use and the current progress in abrogating their inherent toxicity

Role of insulin-like growth factor binding protein-4 in prevention of colon cancer

Insulin-like growth factors (IGFs) are important for the proliferation of cancer cells. One of their binding proteins, known as insulin-like growth factor binding protein -4 (IGFBP-4) is well known for its inhibitory action on IGFs in vitro. We assessed the effect of IGFBP-4 in prevention of development of colon cancer in vivo

Cyclooxygenase/lipoxygenase shunting lowers the anti-cancer effect of cyclooxygenase-2 inhibition in colorectal cancer cells

BACKGROUND: Arachidonic acid metabolite, generated by cyclooxygenase (COX), is implicated in the colorectal cancer (CRC) pathogenesis. Inhibiting COX may therefore have anti-carcinogenic effects. Results from use of non-steroidal anti-inflammatory drugs inhibiting only COX have been conflicting. It has been postulated that this might result from the shunting of arachidonic acid metabolism to the 5-lipoxygenase (5-LOX) pathway. Cancer cell viability is promoted by 5-LOX through several mechanisms that are similar to those of cyclooxygenase-2 (COX-2). Expression of 5-LOX is upregulated in colorectal adenoma and cancer. The aim of this study was to investigate the shunting of arachidonic acid metabolism to the 5-LOX pathway by cyclooxygenase inhibition and to determine if this process antagonizes the anti-cancer effect in colorectal cancer cells. METHODS: Three colorectal cancer cell lines (HCA7, HT-29 & LoVo) expressing 5-LOX and different levels of COX-2 expression were used. The effects of aspirin (a non-selective COX inhibitor) and rofecoxib (COX-2 selective) on prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) secretion were quantified by ELISA. Proliferation and viability were studied by quantifying double-stranded DNA (dsDNA) content and metabolic activity. Apoptosis was determined by annexin V and propidium iodide staining using confocal microscopy, and caspase-3/7 activity by fluorescent substrate assay. RESULTS: COX inhibitors suppressed PGE(2) production but enhanced LTB(4) secretion in COX-2 expressing cell lines (P <0.001). The level of COX-2 expression in colorectal cancer cells did not significantly influence the anti-proliferative and pro-apoptotic effects of COX inhibitors due to the shunting mechanism. CONCLUSIONS: This study provides evidence of shunting between COX and 5-LOX pathways in the presence of unilateral inhibition, and may explain the conflicting anti-carcinogenic effects reported with use of COX inhibitors

Inducing apoptosis of human colon cancer cells by an IGF-I D domain analogue peptide

Background: The resistance of tumour cells to apoptosis is a major contributor to the limited effectiveness of chemotherapies. Insulin-like growth factor I (IGF-I) has potential to protect cancer cells from variety of apoptotic challenges. This study was carried out to investigate the effect of a novel IGF-I receptor antagonist on apoptosis in colon cancer cells.Results: We have designed and synthesised a novel antagonist of IGF-I receptor. The effect of this antagonist on human colon cancer cell proliferation was examined by a non-radioactive assay; the apoptosis was revealed by determining the activities of cellular caspases3/7, 8 and 9. The apoptosis pathways were investigated by examining the levels of pro-apoptosis proteins with Western blotting. Following 40 hours treatment with the novel antagonist peptide, colon cancer cell Caspase 3/7 activities increased 2-7 times; Caspase 8 activities increased 2-5 times and Caspase 9 increased 1.2-1.6 times. The proliferation of cancer cell was inhibited by 14-15%. The data showed that the antagonist induced colon cancer cell apoptosis and inhibited cancer cell proliferation. The different changes of Caspase 3/7, 8 and 9 activities suggested that the extrinsic pathways may play a major role in the antagonist peptide-induced apoptosis.Conclusion: This is the first report on this novel antagonist to induce human colon cancer cell apoptosis and inhibit cancer cell proliferation. These results suggest that IGF-I receptor antagonists may have the potential to be developed as a novel therapy for colon cancers in the future

A concise review of carbon nanotube's toxicology

Carbon nanotubes can be either single-walled or multi-walled, each of which is known to have a different electron arrangement and as a result have different properties. However, the shared unique properties of both types of carbon nanotubes (CNT) allow for their potential use in various biomedical devices and therapies. Some of the most common properties of these materials include the ability to absorb near-infra-red light and generate heat, the ability to deliver drugs in a cellular environment, their light weight, and chemical stability. These properties have encouraged scientists to further investigate CNTs as a tool for thermal treatment of cancer and drug delivery agents. Various promising data have so far been obtained about the usage of CNTs for cancer treatment; however, toxicity of pure CNTs represents a major challenge for clinical application. Various techniques both in vivo and in in vitro have been conducted by a number of different research groups to establish the factors which have a direct effect on CNT-mediated cytotoxicity. The main analysis techniques include using Alamar blue, MTT, and Trypan blue assays. Successful interpretation of these results is difficult because the CNTs can significantly disrupt the emission of the certain particles, which these assays detect. In contrast, in vivo studies allow for the measurement of toxicity and pathology caused by CNTs on an organismal level. Despite the drawbacks of in vitro studies, they have been invaluable in identifying important toxicity factors, such as size, shape, purity, and functionalisation, the latter of which can attenuate CNT toxicity