The application of the sol-gel technology to develop host materials for cell-based biotechnological devices has been continuously explored over the last 20 years. The most recent progress allowed the diversification of the chemical nature and structure of the inorganic or hybrid matrices, together with extension of cell types whose viability and biological activity could be preserved in the long-term. As a result, the range of potential applications of these ``living materials'' currently encompasses major fields of materials science at its interface with living systems, with particular interest in bioremediation and tissue engineering. Future developments will rely on continuous efforts to adapt materials chemistry to the conditions of life together with a better understanding and control of the influence of confinement on cellular activity.