Are we prepared for animal cell technology in the 21st century?

Large scale animal cell culture for the production of complex therapeutic proteins has been a major success of the biotechnology industry. Today, approximately half of the $ 5 billion annual turnover of the biotechnology industry is based upon this technology, in many cases with reactors of more than 10 m(3). As we look towards the 21 st century, however, we can see novel approaches to the production of therapeutic proteins, by means of gene and cellular therapies. These technologies present new engineering challenges to the animal cell technologist. Are we prepared to meet these challenges? The needs include: small-scale reactors for the preparation of autologous cell lines, methods for the production of viruses to be used as vectors in gene therapy, artificial organ and the processing of xenogenic cell lines and tissues for cellular implants in humans. More attention should be given to three-dimensional cell cultures. Mass transfer considerations need to be extended beyond just oxygen transfer, to include cellular communication in small systems; this is becoming increasingly important for the control and optimise growth and product formation. Apart from improvements of large-scale systems, substantial advantages could be gained by studying new methods for the production and delivery of therapeutic proteins, using small-scale cell culture systems. We should adapt teaching, regulatory, patent and clinical infrastructure to meet this challenge in a harmonious way.