A polymeric substrate has a plasma treated contact surface which is roughened, hydrophilic and has a higher oxygen atomic content than the interior portion. The treated contact surface has an enhanced cell adhesion, cell growth and cell recovery rate. During the treatment, the contact surface is contacted with a process gas introduced through a gas inlet near the treated surface and radio frequency electrical power is introduced in the process gas, forming a treated contact surface that has improved cell recovery compared to an untreated contact surface. The process gas optionally can be nitrogen gas, oxygen gas, or a gas that contains nitrogen atoms, oxygen atoms, or a combination of nitrogen and oxygen atoms. The process optionally improves cell recovery of a chicken embryo cell culture from the treated contact surface.