Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel

doi:10.1073/pnas.0508432103

Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel

^*Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; ^†Protista Biotechnology AB, Ideon, SE-223 70 Lund, Sweden; and ^‡Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur-208016, India

Edited by Alexander M. Klibanov, Massachusetts Institute of Technology, Cambridge, MA, and approved December 5, 2005 (received for review October 6, 2005)

Abstract

Adsorption of bioparticles to affinity surfaces involves polyvalent interactions, complicating greatly the recovery of the adsorbed material. A unique system for the efficient binding and release of different cells and particles is described. Affinity-bound bioparticles and synthetic particles are detached from the macroporous hydrogel matrix, a so-called cryogel, when the cryogel undergoes elastic deformation. The particle detachment upon elastic deformation is believed to be due to breaking of many of the multipoint attachments between the particles and the affinity matrix and the change in the distance between affinity ligands when the matrix is deformed. However, no release of affinity-bound protein occurred upon elastic deformation. The phenomenon of particle detachment upon elastic deformation is believed to be of a generic nature, because it was demonstrated for a variety of bioparticles of different sizes and for synthetic particles, for different ligand–receptor pairs (IgG–protein A, sugar–ConA, metal ion–chelating ligand), and when the deformation was caused by either external forces (mechanical deformation) or internal forces (the shrinkage of thermosensitive, macroporous hydrogel upon an increase in temperature). The elasticity of cryogel monoliths ensures high recovery of captured cells under mild conditions, with highly retained viability. This property, along with their continuous porous structure makes cryogel monoliths very attractive for applications in affinity cell separation.

Footnotes

↵ § To whom correspondence should be addressed. E-mail: bo.mattiasson{at}biotek.lu.se.
Conflict of interest statement: No conflicts declared.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations: IDA, iminodiacetate; LDH, lactate dehydrogenase; PVA, poly(vinyl alcohol).