Local targeted “inside-out” hyperthermia of tumors via nanoparticles is able to sensitize tumor cells to chemotherapy, radiation therapy, gene therapy, immunotherapy, or other effects, significantly reducing the duration and intensity of treatment. In this article, new nanomaterials are proposed to be used as anticancer agents: boron-doped nanodiamonds with sizes of about 10 nm synthesized for the first time by the high-temperature high-pressure (HTHP) method. The heating ability of boron-doped nanodiamonds was investigated under different heating conditions in different environments: water, chicken egg white, and MCF-7 breast cancer cells. It was discovered that, with the same conversion of the absorbed energy into heat, the ability to heat the environment when excited at a wavelength of 808 nm of boron-doped nanodiamonds is much higher than that of detonation nanodiamonds. It was established that boron-doped nanodiamonds are extremely promising for carrying out hyperthermia and thermoablation of tumors.

The interactions of one of the most famous enzymes, lysozyme, with carboxylated nanodiamonds in water were studied. It was found that stable complexes are formed as a result of lysozyme adsorption on the surface of nanodiamonds. Based on the obtained adsorption isotherms and change in the fluorescence of nanodiamonds during the adsorption of lysozyme on them, it is concluded that lysozyme is adsorbed on carboxylated nanodiamonds in two layers. Numerical estimates and IR absorption spectroscopy data showed that the lysozyme has different adsorption orientations in the first and second layers, with preferential side-on and end-on orientations, correspondingly. Moreover, in the first layer, lysozyme undergoes significant conformational changes. The enzymatic activity of adsorbed lysozyme in both layers is discussed.

Appropriate analysis of biological tissue deep regions is important for tumor targeting. This paper is concentrated on photons’ paths analysis in such biotissue as brain, because optical probing depth of fluorescent and excitation radiation differs. A method for photon track reconstruction was developed. Images were captured focusing on the transparent wall close and parallel to the source fibres, placed in brain tissue phantoms. The images were processed to reconstruct the photons most probable paths between two fibres. Results were compared with Monte Carlo simulations and diffusion approximation of the radiative transfer equation. It was shown that the excitation radiation optical probing depth is twice more than for the fluorescent photons. The way of fluorescent radiation spreading was discussed. Because of fluorescent and excitation radiation spreads in different ways, and the effective anisotropy factor,geff, was proposed for fluorescent radiation. For the brain tissue phantoms it were found to be0.62±0.05and0.66±0.05for the irradiation wavelengths 532 nm and 632.8 nm, respectively. These calculations give more accurate information about the tumor location in biotissue. Reconstruction of photon paths allows fluorescent and excitation probing depths determination. Thegeffcan be used as simplified parameter for calculations of fluorescence probing depth.

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The study demonstrates the ability of fluorescence diagnosis to perform intraoperative analysis of the bladder wall. The data of 10 patients with superficial bladder cancer who underwent PDD with the use of the fluorescence video system with excitation wavelenght in the “red” wavelength range and TUR is discussed. General condition of the bladder is assessed, the main foci of the tumor are determined. Then a tumor resection is performed. Further examination and identification of the fluorescing boundaries of the tumor remaining after TUR is performed to make a decision of a re‐resection. In addition, small fluorescing tumor foci, not detected with WL cystoscopy, are detected. Moreover the diagnostic fluorescence contrast is measured, allowing quantitative assessment of the 5‐ALA accumulation in tissues. The applied laser wavelength of 635 nm allows the light to penetrate deeper into the bladder tissue, making it possible to detect tumors including in the deeper layers.

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