A method. The method includes providing a filter medium comprising a functionalized nonwoven; passing a first fluid containing cells through the filter medium, wherein at least some of the cells are captured by the functionalized nonwoven; passing a second fluid, and optionally a third and/or fourth fluid through the filter medium, wherein the second and/or third and/or fourth fluid disrupts at least one of the captured cells; and recovering an intracellular biological product in the first and/or second and/or third and/or fourth fluid.