Adsorptive recovery of nanoparticulate protein products : physical and biochemical characterisation of candidate solid phases
Adsorbent solid phases having suitable designs applicable to the generic recovery of nanoparticulate products have been demonstrated. Practical recovery of nanoparticulate mimics, of products such as plasmid DNA and viruses, as putative gene therapy vectors from both single component model systems and complex feedstocks has been studied. The adsorbents employed in the study had one of four discrete designs (Type I-IV), including (I) microporous (pore size 0.02um- 0.2um), (II) macroporous (pore size > 0.6um), (III) solid (non-porous) and (IV) pellicular (pore size 0.2nm-0.4um). Commercially available adsorbents (STREAMLINE, Amersham Biosciences; Toyopearl HW-40, Tosohaas; POROS SOD, Applied Biosystems) and custom designed adsorbents (PVA composites supplied by Igor Galaev, Lund University; Celbead adsorbents supplied by Arvind Lali, Mumbai University; 2% ZsA and perfluorocarbon emulsions developed at the University of Birmingham) were included in the study. Insect cell culture lysate was employed as an industrially relevant feedstock and experiments were completed exploiting representative nanoparticulate production systems. The adsorptive capacity and desorption efficiency of both nanoparticulate products and cellular component were strongly influenced by the physical design and geometry of the adsorbent solid phases together with the concentrations of interacting chemical ligands available for adsorption. Microporous adsorbents (as defined above) developed for the purification of macromolecular products appeared to be less suited for the recovery of nanoparticulate products from complex feedstocks than macroporous or pellicular adsorbents.