Theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy in the absorption band of porphyrin

We report the results of developing a technique for theranostics of skin neoplasms based on luminescence diagnostics in combination with photodynamic therapy (PDT) in the absorption band of porphyrin. It is shown that the therapeutic effect is achieved exclusively due to PDT, without the participation of the hyperthermia process, which occurs at temperatures above 42 °C. The Fluroscan gel [based on the dipotassium salt of the ytterbium complex of 2,4-di-(a-methoxyethyl)deuteroporphyrin IX (Yb-DMDP)] is used as a preparation for theranostics. The main photophysical properties and possible mechanisms of accumulation of nanosized low-toxic photosensitisers based on this compound are studied. It is shown that the Yb-DMDP compound in a DMSO solution (30% aqueous DMSO) enhances photophysical characteristics (luminescence lifetime 5-10 ms, luminescence quantum yield up to 1%, extinction coefficient ~1.96 × 105 M-1 cm-1 at a wavelength of 398 nm). Experimental animals are used to test the proposed technique for theranostics of tumours using the Fluroscan gel and a fibre-optic laser fluorimeter.

Eye-Safe Wavelength Laser Fluorimeter for Noncontact Monitoring the Ecological Condition of Objects in Natural Environment

Presently, a problem of ecological monitoring of natural environment is critical.Laser methods are the most powerful to provide noncontact and remote ecological monitoring of natural environment. Among laser monitoring methods, laser fluorescent ones are of strong interest.Today, there are laser fluorescent devices designed to monitor ecological condition of various objects in natural environment. To produce laser-induced fluorescence excitation, laser fluorescent devices use a variety of radiation sources in the spectral band from 226 to 635 nm.However, to have an advanced laser fluorescent device for noncontact ecological monitoring of natural environment, devices to be created should be multifunctional and use an eye-safe wavelength for fluorescence excitation.A fluorescence excitation wavelength of 355 nm (the third harmonic of a YAG: Nd laser) appears to be promising. This wavelength is eye-safe and can be used to monitor ecological condition of a large number of nature-made objects.The paper conducts a capability analysis of noncontact laser fluorescent monitoring of ecological condition of natural environment using the eye-safe fluorescence excitation wavelength of 355 nm. Describes a laser fluorimeter mock-up and presents experimental results of laser-induced fluorescence spectra of nature-made objects.The experimental studies have shown that the noncontact laser fluorimeter using the eye-safe fluorescence excitation wavelength of 355nm potentially allows us to control the ecological condition of a large number of nature-made objects.The fluorescence intensities in the certain spectral ranges (for example, within the spectral range of ~ 425 – 450 nm) and a spectrum profile of plant fluorescence (in the spectral range of 670 - 750 nm) can be used as the controlled variables.