| Abstract [eng] |
Bladder cancer is one of the most common malignancies of the urinary system. Cystoscopy and urine or bladder washing cytology methods are commonly used in clinical trials for the diagnosis of bladder cancer. They are effective in diagnosing tumors with a high degree of differentiation, but have low susceptibility to low-grade and early-stage tumors. Therefore, effective identification of bladder tumors requires new reliable diagnostic methods that enable rapid and accurate characterization of samples. The aim of this work was to apply the SERS method for the identification of bladder cancer. The goals of this study: 1. To determine the optimal method of preparation of colloidal silver nanoparticle solution. 2. To collect the SERS spectra of different patients’ bladder tissues, their intercellular fluid, and bladder washings and to determine spectral markers of bladder cancer. 3. To evaluate the suitability of the SERS method for bladder tumor identification. It was determined that the Raman scattering signal of uric acid is most effectively enhanced by a colloidal solution of silver nanoparticles centrifuged at 6500 rpm. The nanoparticle layers prepared using this colloidal solution show about a 16 times bigger intensity of the Raman scattering signal of the molecule compared to the non-centrifuged colloidal solution. Using the optimal colloidal solution, SERS spectra of healthy, cancerous and cystitis-affected bladder tissues, their extracellular fluid and bladder washings were collected. Analysis of the collected SERS spectra of bladder samples from different patients revealed spectral markers that allow the identification of cancerous and cystitis-affected tissue. The vibrational band in the SERS spectra of the extracellular fluid layers, which is attributed to the vibrations of proteins and lipids (1052 cm-1), was found to be the most suitable for bladder cancer diagnosis and the change of its intensity may be related to the tumor category and, in the case of papillary carcinoma, the degree of differentiation of cells. The PCA of collected SERS spectra of extracellular fluid of 30 patients showed that based on changes in the intensity of the spectral band located at 1052 cm-1 tumor could be identified with 81 % accuracy. |
