A Thermoresponsive and Magnetic Colloid for 3D Cell Expansion and Reconfiguration

Abstract

A dual thermoresponsive and magnetic colloidal gel matrix is described for enhanced stem‐cell culture. The combined properties of the material allow enzyme‐free passaging and expansion of mesenchymal stem cells, as well as isolation of cells postculture by the simple process of lowering the temperature and applying an external magnetic field. The colloidal gel can be reconfigured with thermal and magnetic stimuli to allow patterning of cells in discrete zones and to control movement of cells within the porous matrix during culture.

Upper critical solution temperature thermo-responsive polymer brushes and a mechanism for controlled cell attachment

“…The longer-term culture experiments thus demonstrated that the surfaces were able to function as 'reversible attachment' cell support matrices over timescales generally used for cell expansion. The utility of switchable attachment to polymer surfaces for cell culture has been extensively tested over recent years, 31,32 but the ability to culture cells at lower temperature and then release the cells by heating to body temperature may offer advantages for more thermally sensitive cell types. Overall, these results are significant also because they demonstrate a mechanism underlying the cell adhesion phenomenon.…”

The electrospinning of a thermo-responsive polymer with peptide conjugates for phenotype support and extracellular matrix production of therapeutically relevant mammalian cells

“…In recent years, thermo-responsive surfaces 7,8 have been used as supports for mammalian cell culture, as their changes in physicochemical properties at upper or lower critical solution temperatures (UCST, LCST) can facilitate cell detachment without the need for enzymatic passaging. [9][10][11][12][13] PNIPAM is the most commonly used thermo-responsive polymer, however, the presence of strong hydrogen bond donors and hydrogen acceptors in its structure can lead to inter-and intra-chain association entanglement. 14 By comparison, PEG-based polymers have a reversible phase transition that occurs without chain entanglement.…”

Thermoresponsive magnetic colloidal gels via surface-initiated polymerisation from functional microparticles

“…Previous data had shown that PDEGMA adsorbed onto polystyrene-DVB microparticles with magnetic cores did not lead to any cytotoxicity in fibroblasts or stem cells. 18 Cell adhesion, distribution, viability and proliferation were thus evaluated. The thermoreversible fluid-to-gel transition of the colloidal gels allowed easy cell seeding when the gels were in their 10 | J.…”

“…18 Diethyleneglycolmethaacrylate (11 g, 59 mmol) was weighed into a round bottom flask and 1-dodecanethiol (0.08 g, 0.4 mmol) and 20 ml of 2-butanone were added. AIBN (0.07 g, 0.4 mmol) was added and the mixture was degassed with nitrogen for 25 minutes.…”

“…[15][16][17] In addition, coupling of thermoresponsive polymers to magnetite-containing microspheres has recently been shown to enhance the culture and expansion of stem cells, and facilitate rapid recovery of the expanded cell population by simple magnetic separation. 18 The 'switchable' component of reversibly associating colloidal microparticles can be generated by attaching the thermoresponsive polymer either by physical adsorption 19,20 or chemical grafting. 21,22 The most simple method i.e.…”