Dual-layer culture substrate

A transparent dual-layer substrate for culturing a cell and/or a tissue by air-liquid interface culture, comprising a porous cellulose derivative membrane on which polymer microfibers are spun and laminated, wherein the porous cellulose derivative membrane is light permeable under a wet condition, wherein the transparent dual-layer substrate is manufactured by a method comprising the steps of:

• 1) dissolving a cellulose derivative in an organic solvent to prepare an organic solvent solution of the cellulose derivative;
• 2) coating a substrate with the organic solvent solution of the cellulose derivative and drying it to prepare a cellulose derivative membrane;
• 3) drying the cellulose derivative membrane for a prescribed period of time, immersing the membrane in hot water for a prescribed period of time, immersing the membrane in cold water for another prescribed period of time, and then peeling the membrane from the substrate to prepare a porous cellulose derivative membrane;
• and
• 4) spinning polymer microfibers on the porous cellulose derivative membrane by electrospinning to laminate the porous cellulose derivative membrane with the polymer microfibers,
• wherein coating thickness in the step 2) is from 150 to 200 μm, and an upper half of the membrane has an average porous diameter of 0.306 μm while a lower half of the membrane has an average porous diameter of 0.515 μm.