Hostname: page-component-77c89778f8-rkxrd Total loading time: 0 Render date: 2024-07-17T12:53:56.405Z Has data issue: false hasContentIssue false

Synthesis of Thermoresponsive Copolymers Composed of Poly(ethylene oxide) and Poly(N-isopropylacrylamide) for Cell Encapsulation

Published online by Cambridge University Press:  01 February 2011

Tatiya Trongsatitkul
Affiliation:
Tatiya_Trongsatitkul@student.uml.edu, Univeristy of Massachusetts, Plastics Engineering, Lowell, Massachusetts, United States
Bridgette Budhlall
Affiliation:
Bridgette_Budhlall@uml.edu, Univeristy of Massachusetts, Plastics Engineering, Lowell, Massachusetts, United States
Get access

Abstract

Thermoresponsive copolymers of poly(N- isopropyl acrylamide) (PNIPAm) and poly(acrylamide) microgels grafted with poly(ethylene glycol)(PEG) chains were synthesized by free-radical photopolymerization. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers with varying number-average molecular weights were used (Mn = 300 and 1,000 g/mol). A simple microarray technique coupled with a laser scanning confocal microscope (LSCM) was used to visualize the effect of temperature on the volume phase transition temperatures of the microgels. In general, increasing the concentration of PEGMA in the PNIPAm-co-Am-co-PEGMA copolymers resulted in a broader and higher lower critical solution temperature (LCST) compared to the PNIPAm microgels. We demonstrated that the PEGMA molecular weight and concentration influenced whether it was incorporated as a grafted copolymer or random copolymer in the PNIPAm microgel. The evidence for this is the shift in the LCST as determined by temperature and differential scanning calorimetry (DSC) measurements. This behavior suggests that incorporation of PEGMA in the copolymer depends on its hydrophilicity or water-solubility which in turn influenced the degree at which the copolymer chains collapsed from a coil-to-globule (volume phase transition) with increasing temperature.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Virtanen, J., Baron, C., and Tenhu, H., “Grafting of Poly(N-isopropylacrylamide) with Poly(ethylene oxide) under Various Reaction Conditions,” Macromolecules, vol. 33, pp. 336341, 2000.Google Scholar
[2] Orive, G., Hernandez, R. M., Gascon, A. R., Calafiore, R., Chang, T. M. S., Vos, P. D., Hortelano, G., Hunkeler, D., Lacik, I., Shapiro, A. M. J., and Pedraz, J. L., “Cell encapsulation: Promise and progress,” Nat Med, vol. 9, pp. 104107, 2003.Google Scholar
[3] Gan, D. and Lyon, L. A., “Synthesis and Protein Adsorption Resistance of PEG-Modified Poly(N-isopropylacrylamide) Core/Shell Microgels,” Macromolecules, vol. 35, pp. 96349639, 2002.Google Scholar
[4] Sershen, G. A. M. S. R., Ng, M., Halas, N. J., Beebe, D. J., West, J. L.,, “Independent Optical Control of Microfluidic Valves Formed from Optomechanically Responsive Nanocomposite Hydrogels,” Advanced Materials, vol. 17, pp. 13661368, 2005.Google Scholar
[5] Weissleder, R., “A clearer vision for in vivo imaging,” Nat Biotech, vol. 19, pp. 316317, 2001.Google Scholar
[6] Jones, C. D. and Lyon, L. A., “Synthesis and Characterization of Multiresponsive Core&Shell Microgels,” Macromolecules, vol. 33, pp. 83018306, 2000.Google Scholar
[7] Janevieve, N. N., Jones, A., Flagler, Kendra, Pagnucco, Christina D., Carew, Steve, Cheong, Charles, Kong, Xiang Z., Burke, Nicholas A. D., Stöver, Harald D. H.,, “Thermoresponsive copolymers of methacrylic acid and poly(ethylene glycol) methyl ether methacrylate,” Journal of Polymer Science Part A: Polymer Chemistry, vol. 43, pp. 60956104, 2005.Google Scholar