Hydrogel materials are one of the most versatile representatives of biomaterials. Their widespread use in medical practice is due to their similarity to native biostructures regarding relevant properties. This article discusses the synthesis of hydrogels based on a plasma-substituting Gelatinol® solution and modified tannin, carried out by direct mixing of the two solutions and brief heating. This approach makes it possible to obtain materials based on precursors that are safe for humans, while having antibacterial activity and high adhesion to human skin. Thanks to the synthesis scheme used, it is possible to obtain hydrogels with a complex shape before use, which is relevant in cases where industrial hydrogels do not fully satisfy the end use regarding their form factor. Using IR spectroscopy and thermal analysis, the distinctive aspects of mesh formation were shown in comparison with the hydrogels based on ordinary gelatin. A number of application properties, such as the physical and mechanical characteristics, permeability to oxygen/moisture, and antibacterial effect, were also considered. The sorption parameters of the material were characterized in a set of physiological buffers (pH 2–9) using Fick’s first law and a pseudo-second order equation. The adhesive shear strength was determined in a model system. The synthesized hydrogels showed potential for the further development of materials based on plasma-substituting solutions.