Recovery in aqueous two-phase systems of nanoparticulates applied as surrogate mimics for viral gene therapy vectors

The partition behaviour of nanoparticulate inclusion bodies (IBs) in variou s states of purity were evaluated as surrogate mimics for adenovirus and re trovirus products in method scouting experiments with aqueous two-phase sys tems (ATPSs). Such systems are proposed for effective, high capacity downst ream processing (DSP) of viral gene therapy vectors. Studies with mimics pr ovided simple descriptions of particle partition which may benefit the fiel d of vector DSP, where experimental material is rarely available for resear ch and development in quantities and concentrations representative of clini cal manufacture. Polyethylene glycol (PEG)-salt and PEG-dextran ATPSs were screened in respect of the partition recovery of IBs from crude feedstocks. Select candidate systems were similarly evaluated with limited preparation s of adenovirus and retrovirus with respect to fractional recoveries of inf ectivity and particle number. Maintenance of the former was good, whilst co mparison of the latter with quantitation of unwashed and washed IBs indicat ed poor utilisation of the inherent high capacities of ATPSs in viral exper iments. This is discussed in the context of the volumetric throughput and c apacities reported in the literature for the recovery of infective viruses in ultracentrifugation and chromatographic processes. (C) 2000 Elsevier Sci ence B.V. All rights reserved.