The aim of the study was to assess the integral outcomes of implantation biocompatible scaffold as the carrier of neural stem cells in the reconstructive surgery of open traumatic brain injury (TBI) by parameters of neurological and cognitive status of the animals in the experiment.Materials and Methods. Adult male C57BL/6 mice were injured with open-skull weight-drop method. 3D hydrogel scaffold based on modified chitosan in complex with hyaluronic acid was transplanted into the lesion cavity 1 week after TBI. Using a variety of behavioral and cognitive tests (modified neurological severity scores (mNSS), open field test as well as novel object recognition and passive avoidance tests) the short-and long-term neurological and memory functions sequelae induced by TBI were assessed. Magnetic resonance imaging was used to visualize the injury site.Results. Significant functional recovery was observed on both the mNSS and open field tests in the scaffold transplantation group compared to the control TBI group. In addition, enhanced improvement of short and long-term memory functions was found 5 months post injury. Magnetic resonance imaging data revealed that the scaffold transplantation result in decreasing of the volume of injury area compared to control TBI group and preventing the disruption of the neural networks of the brain. NeuroscieNce researchConclusion. Taken together, our findings indicated that transplantation of 3D biodegradable scaffold into injury cavity contributed to the preservation of volume in the damaged region in the first months after TBI which in turn led to a better functional recovery in the remote period.