Scalable CAR-NK Cell Expansion Using Vertical-Wheel Bioreactors with XCell ATF Perfusion

This application note evaluates scalable chimeric antigen receptor natural killer (CAR-NK) cell expansion in PBS Vertical-Wheel bioreactors integrated with Repligen XCell alternating tangential flow perfusion. Human peripheral blood NK cells were activated, transduced, and expanded in PBS-3 bioreactors using batch, fed-batch, or perfusion feeding. Studies assessed cell growth, glucose and lactate trends, apoptosis, CAR expression, harvest, cryopreservation, and cytotoxic potency. A responsive perfusion strategy initiated from cell-density and glucose measurements improved expansion compared with fixed scheduling and maintained similar cell health before and after perfusion. At 3 L scale, perfusion produced higher expansion than fed-batch culture from the same donor, while PBS-3-expanded cells demonstrated greater relative potency than a static G-Rex control. The document also describes XCell ATF 2 integration and medium-exchange operation for CAR-NK manufacturing.