Colorectal cancer (CRC) ranks among the most common cancers worldwide. Surgical removal remains the best strategy for treatment of resectable tumors. An important part of caring for patients after surgery is monitoring for early detection of a possible relapse of the disease. Efforts are being made to improve the sensitivity and specificity of routinely used carcinoembryonic antigen (CEA) with the use of additional biomarkers such as microRNAs. The aim of our study was to evaluate the prognostic potential of microRNAs and their use as markers of disease recurrence. The quantitative estimation of CEA, CA19-9, and 22 selected microRNAs (TaqMan Advanced miRNA Assays) was performed in 85 paired (preoperative and postoperative) blood plasma samples of CRC patients and in samples taken during the follow-up period. We have revealed a statistically significant decrease in plasma levels for miR-20a, miR-23a, miR-210, and miR-223a (p = 0.0093, p = 0.0013, p = 0.0392, and p = 0.0214, respectively) after surgical removal of the tumor tissue. A statistically significant relation to prognosis (overall survival; OS) was recorded for preoperative plasma levels of miR-20a, miR-21, and miR-23a (p = 0.0236, p = 0.0316, and p =0.0271, respectively) in a subgroup of patients who underwent palliative surgery. The best discrimination between patients with favorable and unfavorable outcomes was achieved by a combination of CEA, CA19-9 with miR-21, miR-20a, and miR-23a (p < 0.0001). The use of these microRNAs for early disease recurrence detection was affected by a low specificity in comparison with CEA and CA19-9. CEA and CA19-9 had high specificity but low sensitivity. Our results show the benefit of combining currently used standard biomarkers and microRNAs for precise prognosis estimation.

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Ultra-small nanoparticles with sizes comparable to those of pores in the cellular membrane possess significant potential for application in the field of biomedicine. Silicon carbide ultra-small nanoparticles with varying surface termination were tested for the biological system represented by different human cells (using a human osteoblastic cell line as the reference system and a monocyte/macrophage cell line as immune cells). The three tested nanoparticle surface terminations resulted in the observation of different effects on cell metabolic activity. These effects were mostly noticeable in cases of monocytic cells, where each type of particle caused a completely different response (‘as-prepared’ particles, i.e., were highly cytotoxic, –OH terminated particles slightly increased the metabolic activity, while –NH2 terminated particles caused an almost doubled metabolic activity) after 24 h of incubation. Subsequently, the release of cytokines from such treated monocytes and their differentiation into activated cells was determined. The results revealed the potential modulation of immune cell behavior following stimulation with particular ultra-small nanoparticles, thus opening up new fields for novel silicon carbide nanoparticle biomedical applications.

Silicon quantum dots (SiQDs) are interesting low-dimensional nanostructures whose unique optical and electronic properties can be exploited for imaging, biosensing, or drug delivery. SiQDs with a diameter of around 4 nm co-doped with boron and phosphorus and evincing fluorescence and dispersibility in aqueous solutions were studied with respect to their impact on different human cells. The level of SiQD cytotoxicity in different types of human cells À osteoblasts, monocytes, macrophages, and mesenchymal stromal cells À was determined. Exposing the cells to increasing concentrations of quantum dots under different conditions and the subsequent evaluation of their cytotoxicity provided an overview of cell-specific reactions to identical doses. The results revealed the importance of cultivation conditions (e.g., the formation of a protein corona on nanoparticles originating from the media supplement) as well as the significant impact of cell type (the increased sensitivity of monocytes to quantum dots in comparison to other cell types).