The influence of low process temperature on the hydrodynamic radius of polyNIPAM-co-PEG thermosensitive nanoparticles presumed as drug carriers for bioactive proteins.

The aim of the work was to evaluate the influence of low process temperature on the hydrodynamic radius of the synthesized nanoparticles presumed for incorporation of bioactive proteins. The reaction prompted in temperatures of 22, 38 and 70 degrees C. The first one reflected the ambient environmental temperature, at which the bioactive proteins may be implemented into the reactant mixture. The intermediate temperature should enable safe use of proteins during the reaction, and represents the upper limit of applied heat, due to the consequent denaturation of proteins at elevated temperatures. The reactant mixture heated up to 70 degrees C provides excellent formation of nanoparticles, however the albuminous components will tend to degrade. Within the study we applied N,N,N',N'-tetramethylethane-1,2-diamine as an accelerator in the presence of the strong oxidizing agent--ammonium persulfate as radical initiator. Six batches of N-isopropylacrylamide derivatives with polyoxyethylene glycol diacrylamide co-monomer of molecular weight in the range of 2000 Da were synthesized within the course of surfactant free precipitation polymerization. The nanodispersions were assessed in the terms of hydrodynamic radius, by the dynamic light scattering method (DLS). The polydispersity index, as well as average hydrodynamic radius, and hydrodynamic radius of main population of particles, identified in the DLS device, were evaluated and discussed in the perspective of application of the nanogels as drug carriers for bioactive proteins.