At present, biodegradable and biocompatible membranes based on collagen and glycosaminoglycans play an important role in substitutive medicine. Modern biomaterials use a chemically modified collagen-based matrix for implants with programmable biodegradability as a substitute of buccal mucosa, skin, cartilage, etc. Besides the requirements for biocompatibility and biodegradability, the membranes must be also non-toxic. Therefore, cytotoxicity testing of these materials in vitro is an integral part of introducing newly developed types of membranes into clinical practice. As a biological model for the tested COLADERM membrane, cell cultures from human embryonic fibroblasts (B-HEF-2) were used for both cytotoxicity testing as well as in tests to assess the ability of cells to proliferate on this membrane. Along with the ability of cells to grow on the surface and inside the membrane, immunohistochemical examination and scanning electron microscopy (SEM) were performed as well. The obtained results have shown that the COLADERM membrane is non-toxic with suitable structural and biological properties for clinical application as a substitute of buccal mucosa following surgical ablation of malignant tissues from the oral cavity.