###### Abstract  
In this paper, a new approach to treating infected wounds is proposed. It is based on treating the wound surface with high-intensity pulsed optical radiation with a continuous spectrum, continuously covering the entire UV range (from 200 to 400 nm) and the visible and near-infrared regions of the spectrum. A pulsed xenon lamp is used as a radiation source. A description of the design and technical characteristics of the device, \"Zarnitsa-A\", is presented, implementing the proposed medical technology for wound therapy. The results of our studies of the apparatus in vitro and in vivo are also presented. The article shows that exposure to the apparatus leads to pronounced bactericidal- and wound-healing properties. The apparatus's action reliably provides higher rates of wound healing compared with only a typical antibacterial or wound healing agent, such as \"levomekol\" ointment. high-intensity broadband optical irradiation; pulsed xenon lamp; phototherapy device; preclinical studies; bactericidal effect; wound healing Article  
Prelimical Studies of the Anti-Healing Effects of the High-Intensity Optical Irradiation \"Zarnitsa-A\" Apparatus  
[PERSON]; [PERSON]; [PERSON] [PERSON]. ultraviolet (UV) therapy. This is because UV radiation has maximum photochemical and photobiological effects, primarily because of the significant energy of UV photons, which are commensurate with energy in the chemical bonds in biomolecules. In photobiology, ultraviolet radiation is divided into three spectral regions, including the UV-C range (\(\Delta\lambda\) = 200...280 nm), the UV-B range (\(\Delta\lambda\) = 280...315 nm), and the UV-A range (\(\Delta\lambda\) = 315...400 nm) [16]. Various biological effects inherent to these ranges are determined by the energy of photons and the depth of their penetration into biological tissues. Photons in the UV-C range have maximum energy, though their penetration ability is practically limited to the upper layer of the epidermis (the stratum corneum, a layer of inanimate (dead) cells). UV-B radiation penetrates deeper into the basal layer and upper dermal cells, i.e., living cells. UV-A radiation has even greater penetrating power and reaches the upper layers of the dermis (a penetration depth of up to \(\sim\)1 mm); however, its photon energy is noticeably lower than that of the UV-C and UV-B ranges. UV-C and UV-B radiation are strongly absorbed by DNA and protein molecules, causing various destructive modifications and ultimately leading to cell death. This process determines the strong biocidal effect of short-wavelength UV radiation, with UV-C radiation having the maximum biocidal effect [3; 6; 17]. In this regard, it is widely used to disinfect and sterilize inanimate objects [18; 19]. It can also be directly used to destroy pathogens in infected wounds. UV-B radiation has significantly lower biocidal potential than UV-C, but it is characterized by a maximum erytmal effect, which can expand capillary vessels, increase the permeability of their walls, and increase local blood flow, leading to a local intensification of metabolic processes and stimulating the wound-healing process [3; 4; 17; 20]. Unlike UV-C and UV-B, UV-A radiation is weakly absorbed by DNA; instead, it excites other endogenous chromophores (porphyrins, etc. ), generating various reactive oxygen species in cells, which, on the one hand, activate the cell signaling system, initiating inflammatory and proliferative reactions, and, on the other hand, can cause oxidative damage to DNA bases [3; 16; 21]. The biological (including therapeutic) effect of exposure to UV radiation depends both on the spectral range of the applied radiation (\(\Delta\lambda\)) and on the energy dose of exposure (D) (J/cm\({}^{2}\)).