Encapsulation and adhesion of nanoparticles as a potential biomarker for TNBC cells metastatic propensity

Abstract Metastasis is the main cause of cancer-related mortality; therefore, the ability to predict its propensity can remarkably affect survival rate. Metastasis development is predicted nowadays by lymph-node status, tumor size, histopathology, and genetic testing. However, all these methods may have inaccuracies, and some require weeks to complete. Identifying novel prognostic markers will open an essential source for risk prediction, possibly guiding to elevated patient treatment by personalized strategies. Cancer cell invasion is a critical step in metastasis. The cytoskeletal mechanisms used by metastatic cells for the invasion process are very similar to the utilization of actin cytoskeleton in the endocytosis process. In the current study, the adhesion and encapsulation efficiency of low-cost carboxylate-modified fluorescent nanoparticles by breast cancer cells with high (HM) and low metastatic potential (LM) have been evaluated; benign cells were used as control. Using high-content fluorescence imaging and analysis, we have revealed (within a short time of 1 h), that efficiency of nanoparticles adherence and encapsulation is sufficiently higher in HM cells compared to LM cells, while benign cells are not encapsulating or adhering the particles during experiment time at all. We have utilized custom-made automatic image analysis algorithms to find quantitative co-localization (Pearson’s coefficients) of the nanoparticles with the imaged cells. The method proposed here is straightforward; it does not require especial equipment or expensive materials nor complicated cell manipulations, it may be potentially applicable for various cells, including patient-derived cells. Effortless and quantitative determination of the metastatic likelihood has the potential to be performed using patient-specific biopsy/surgery sample, which will directly influence the choice of protocols for cancer patient’s treatment and, as a result, increase their life expectancy

Biochemical composition and turnover of the extracellular matrix of the normal and degenerate intervertebral disc

Background The intervertebral disc (IVD) is a complex cartilaginous structure which functions to resist biomechanical loads during spinal movement. It consists of the highly viscous cartilaginous nucleus pulposus, which is surrounded laterally by a thick outer ring of fibrous cartilage—the annulus fibrosus—and sandwiched inferiorly and superiorly by the cartilage end-plates. The main extracellular matrix molecules of the disc are collagens, proteoglycans, glycoproteins and elastin. The disc also contains appreciable amounts of water, matrix-degrading protease enzymes and their inhibitors, soluble signalling molecules and various metabolic breakdown products. Methods This review provides a comprehensive description of the biochemical composition of the extracellular matrix of the IVD and, specifically, the proteases involved in its molecular turnover. Quantitation of the turnover rates using racemization of aspartic acid as a molecular clock is also discussed. Conclusions Molecular turnover rates of the major constituent matrix macromolecules of the IVD are found to be particularly slow, especially in the case of collagen. Over a normal human life span, this slow turnover may compromise the structural integrity of the IVD extracellular matrix essential for normal physiological functioning

Normal and Shear Interactions between Hyaluronan–Aggrecan Complexes Mimicking Possible Boundary Lubricants in Articular Cartilage in Synovial Joints

Using a surface force balance, normal and shear interactions have been measured between two atomically smooth surfaces coated with hyaluronan (HA), and with HA/aggrecan (Agg) complexes stabilized by cartilage link protein (LP). Such HA/Agg/LP complexes are the most abundant mobile macromolecular species permeating articular cartilage in synovial joints and have been conjectured to be present as boundary lubricants at its surface. The aim of the present study is to gain insight into the extremely efficient lubrication when two cartilage surfaces slide past each other in healthy joints, and in particular to elucidate the possible role in this of the HA/Agg/LP complexes. Within the range of our parameters, our results reveal that the HA/Agg/LP macromolecular surface complexes are much better boundary lubricants than HA alone, likely because of the higher level of hydration, due to the higher charge density, of the HA/Agg/LP layers with respect to the HA alone. However, the friction coefficients (μ) associated with the mutual interactions and sliding of opposing HA/Agg/LP layers (μ ≈ 0.01 up to pressure <i>P</i> of ca. 12 atm, increasing sharply at higher <i>P</i>) suggest that such complexes by themselves cannot account for the remarkable boundary lubrication observed in mammalian joints (up to <i>P</i> > 50 atm)