Purification of recombinant proteins with magnetic nanoclusters

This thesis focused on the development and analysis of a new class of magnetic fluids for recovery of recombinant proteins from fermentation broth. Magnetic fluids are colloidally stable dispersions of magnetic nanoclusters in water that do not settle gravitational and moderate magnetic fields due to their small size. The magnetic nanoclusters possess large surface area for protein adsorption without any porous structure, resulting in much faster mass transfer than in traditional separations. The magnetic nanoclusters consist of 25-200 nm clusters of 8 nm magnetite (Fe₃0₄) cores coated with poly(acrylic acid-co-styrenesulfonic acid-co-vinylsulfonic acid). For use in separation, clusters must be recoverable from solution. Individual nanoparticles are too small to be recovered efficiently, while 50nm or larger clusters of primary particles are easily recovered. Cluster size depends on polymer molecular weight and hydrophobicity as well as the amount of polymer present at nucleation. When a polymer coating with optimal molecular weight is used in limited amounts, clusters are formed. When the clusters are subsequently coated with additional polymer, the clusters are stable in high ionic strength environments (>5M NaCl), while retaining the necessary cluster size for efficient magnetic recovery.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Ditsch, Andre (Andre Paul)

Advisor dc:contributor.advisor

• T. Alan Hatton and Daniel I.C. Wang.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34160

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34160