A THERMOSENSITIVE CHITOSAN HYDROGELBASED 3D IN VITRO HUMAN NEURONAL CULTURE MODEL

Engineered natural biomaterials, able to perform the sol-gel transition in the presence of cells under specific external stimuli, have gained great attention in the field of tissue engineering and regenerative medicine [1], despite of this, for the encapsulation of neurons and the development of 3D neuronal networks, are still limited. In order to study neuronal (dys)functions and particularly neuronal connectivity, in vitro human brain models need to include not only a chemically and physically relevant microenvironment, but also structural network complexity [2]. To mimic the brain ECM environment, a porous and soft structure is preferred in the design of an artificial neural network. The goal of this study was to demonstrate the versatility of thermosensitive chitosan-based scaffold as an artificial matrix for 3D neuronal networks for in vitro studies and as an injectable-hydrogel for the in-vivo applications or innovative ink for 3D bioprinter. Chitosan is a widely used biomaterial, well known for its biocompatibility, biodegradability, muco-adhesiveness as well as its antibacterial activity [3]. It is already demonstrated that chitosan is able to sustain the development of 3D scaffold for neuronal networks [4]. In this work, chitosan thermogels were fabricated and characterized by different techniques. The scaffold was used to encapsulate primary rat neurons and human-induced neurons cultures to carry out morphological characterization by immunofluorescence techniques and a preliminary electrophysiological characterization of spontaneous activity by Micro-Electrode Arrays.