Monodisperse Biocompatible Thermally Responsive Nanoparticle Hydrogels

Thuy T. Chastek, Thomas Chastek, Aniket Wadajkar, KyTai Nguyen, Steven D. Hudson

Over the last decade, hydrophilic polymer gels of nanoscale size (nanogels) have been extensively investigated due to their many potential applications including biosensors and drug delivery systems. Their ability to swell in suitable hydrophilic solvents to trap numerous substances inside the gel makes them attractive for use in delivery applications such as protein and gene delivery. Particular focus has been directed toward “smart” hydrogels which swell or shrink rapidly in response to external environmental stimuli such as pH, temperature, ionic strength, and electro stimulus. Using microreactors, we synthesize such monodisperse biocompatible thermally responsive nanoparticle poly(N-isopropylacrylamide) hydrogels, and analyze their size with integrated measurement capabilities (on-line dynamic light scattering) that we have developed. These nanoparticles were synthesized by varying the concentrations of N-isopropylacrylamide monomer, biocompatible surfactants (Pluronics L64, P65, and P85), and potassium persulfate initiator. Monodisperse nanoparticles were obtained with optimal conditions. The surfactant concentration significantly affects the resulting particle size. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) colorimetric assay showed these nanoparticles are biocompatible.

Author: Thuy Truong Chastek

Mentor: Steven D. Hudson

Division of Polymers

Room: A 219, Bldg 224

Mail Stop: 8542

Phone: 301-975-4349

Fax: 301-975-4924

Email: thuy.chastek@nist.gov

Sigma Xi member: No

Category: Materials