The present invention refers to a biological membrane of chitosan in a water resistant bilayer for repairing the meningeal tissue (dura mater) and as a scaffold for inducing mesothelial cells and fibroblasts, which would promote the development of specific cells of the biological tissue of dura mater. Due to the development of the present invention, the obtained membrane will preserve the biological active principles, including the phagocyte activation, cytolysis, cytostatic, antibody production, cytosine production, mitogenic activity, antitumor activity and antimicrobial activity, without substantially altering said principles, these being intrinsic characteristics of chitosan and chitin derivatives, therefore obtaining a product that retain the beneficial properties of the raw material, also presenting added beneficial characteristics that promote a synergy between the initial benefits and those added, such as the characteristics required by a suitable dura substitute, a water-resi stant dura closing, admitting infiltration by fibrocytes, fibroblasts, macrophages, lymphocytes, newly formed vessels, as well as the systematic and progressive deposit of collagen fibers, without causing a keloid scar.Esta invención se refiere a una membrana biológica de quitosana en bicapa impermeable para la reparación de tejidos meníngeos (duramadre) y como un andamiaje inductor de células mesoteliales y fibroplastos, que promoverán el desarrollo de las células propias del tejido biológico de la duramadre. Gracias al método desarrollado en la presente invención la membrana obtenida como producto de este método logra preservar los principios activos biológicos en donde se incluyen la activación fagocitaria, citolisis, citostático, producción de anticuerpos, producción de citocinas, actividad mitogénica, actividad antitumoral y actividad antiomicrobiana, sin alteraciones sustanciales de dichos principios, características intrínsecas de la quitosana y otros derivados de la quitina, al
