Polymeric Nanohydrogels of Poly(N-Isopropylacrylamide) Combined with Others Functionalized Monomers: Synthesis and Characterization

Nanohydrogels from inverse microemulsion (w/o) polymerization, at 25°C, of N-isopropylacrylamide (NIPA) and functionalized monomers are described. The functionalized monomers were: N-(pyridine-4-ylmethyl) acrylamide (NP4MAM) and tert-butyl 2-acrylamidoethyl carbamate (2AAECM). The polymeric nanohydrogel obtained was characterized by attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR) and proton nuclear magnetic resonance spectrometry (1HNMR), while their morphology and particle size was assessed by scanning electron microscopy (SEM) and dynamic light scattering. Their thermal properties were studied by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). As a preliminary measure of biocompatibility, in vitro evaluations of the nanohydrogels were carried out by cellular toxicity (colon carcinoma cells, CT-26) and hemocompatibility tests. These evaluations showed that these nanohydrogels were not toxic in the examined concentration range and exhibited preliminary blood compatibility; therefore they could be used in biomedical applications.