notes from a recorded talk on bioreactors (the image above is a muscle bioreactor that stretches out / exercises the cells..pretty cool!)

Julie G. Allickson, PhD, Director of the Wake Forest Institute for Regenerative Medicine

  • bioreactors are used to make kidneys, ears, bone, muscle, blood vessels, heart valves, etc.. have to be easy to ship because they’ll be sent straight to a clinician, interesting!
  • really interesting design factors for mechanical stimulation of these different types of cells..
  • materials must be USP Class VI, ISO 10993 – sterilization might also affect leachables and extractables (?)

Biren Mistry, MS, Celgene Cellular Therapeutics

  • bioreactors can be used to produce allogeneic cell therapies (patient-derived) like CD34+ hematopoetic stem cells, RBC “farming” or immune cells
  • traditional cell therapy platforms require high OPEX and high CAPEX to enable scale-out (rather than scale-up) – but they’re relatively technically simple
  • a 1000L bioreactor might make 200B cells per batch (vs 200L -> 40B) and you’d expect to run 200 batches per year on these (Schirmaier et al 2014)
  • microcarriers: microscopic beads suspended in a stirred tank – cells grow on these biocompatible beads
  • cannot compare RPM across different vessel volumes, but can compare power input (energy dissipation or by impeller tip speed)

Pascal Beauchesne, PhD, Juno Therapeutics

  • there’s been an evolution of sorts from from small molecule drugs to biologics to cell therapies – they’re very selective and can also self-distribute. Doses can be auto-regulated in very interesting ways (you can signal that the cells should die, for instance)
  • there are three approved autologous cell therapy-based products: Carticel (cartilage repair), Provenge (prostate cancer), LaViv (scarring, no longer in production?)
  • he works on adoptive T Cell therapy like CAR (a single chain with variable fragments that can bind to a cancerous cell and activate t-cells) and high affinity t-cell receptors (genetically modified cells with a very high affinity to peptides on cancerous cells)
  • the process: leukapheresis (cell collection), cells are shipped to a facility for washing and activation, gene transfer occurs to genetically engineer the cells, cells are expanded and then infused back to the patient
  • cell expansion must maintain phenotypes and should probably be done in single use culture vessels
  • small scale work will give “some insight” into critical process params: cell health, populations (composition) and functionality (potency) – these are critical quality attributes (CQAs)
  • scaleout has to happen with bioreators controlled from a server: centralized recipes, alarm monitoring, user permissions, run log archive, CFR 21 Part 11 (FDA regs on electronic systems and signatures)
  • culture systems: bags, expandable gabs, G-REX, rocking motion bioreactors, hollow-fiber bioreactors – here is the G-REX system in action:
  • bags may be made from semi-permeable materials: FEP (fluorinated ethylene propylene), polyolefin, EVO copolymers
  • G-REX can supposedly hit 20B+ cells/mL on large surface area systems despite having no online measurements (volume?) versus rocking motion bags: 15M cells/mL
  • some systems need a shear-protecting agent added to the culture
  • hollow fiber can do 100M cells/mL and have online measurements
  • single use consumable designs, if they have open manipulations require ISO 5/ Class 100 BSC – (aka Class II Type A, I think)
    • also need DEHP-free PVC for sterile welding
    • closed sampling systems: bi-directional reusable ports are not considered closed
    • for leak-proof connections bonded > barbed > luer lock, also need to pressure-test
    • single use components need to provide a characterization of their extractables and leachables
  • “more online measurements would be desirable to further automate automated bioreactor control strategies” – especially wrt feed strategies
  • the quantum terumo BCT product is interesting..