Nehring, DirkGonzalez, RobertoCzermak, PeterPörtner, Ralf2010-04-122010-04-122004-07-01http://hdl.handle.net/2097/3574The ability of commercial ceramic asymmetric ultrafiltration membranes with a cut-off of 10 and 20kDa to purify retroviral pseudotype vectors derived from the murine leukemia virus carrying the HIV 1 envelop protein MLV(HIV-1) was studied. To optimize the filtration process a mathematical model of batch wise vector purification was set up. 745 to 1794ml batches of supernatant containing a maximum of 3.2 x 10[superscript]5 colony forming units per ml (cfu/ml) was produced in a 200 ml fixed bed reactor. By cross flow filtration the vector concentration was increased 10-fold with an average recovery of 84.5 ± 4.5 % of the initial infective capacity. Furthermore membrane layer formation and temperature dependent decay of transduction competent vector particles (decay) was included in the mathematical model. A maximal end point titer of 4.1 x 10[superscript]6 cfu/ml was predicted by the model and confirmed reasonably well by experimental data. Transmembrane flow of batch filtration was predicted by solving a set of related differential equations. Our modeling allows scale-up of the process and prediction of process performance including specific issues such as vector degradation.This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).RetrovirusGene therapyPurificationMembrane filtrationLayer formationMathematical modelCeramic membraneText