Thermoresponsive Nanoparticles of Self-Assembled Block Copolymers as Potential Carriers for Drug Delivery and Diagnostics.

Thermally responsive hydrogel nanoparticles composed of self-assembled polystyrene-b-poly(N-isopropylacrylamide)-b-polystyrene block copolymers and fluorescent probe 1-anilinonaphthalene-8-sulfonic acid have been prepared by aerosol flow reactor method. We aimed exploring the relationship of intraparticle morphologies, that were, PS spheres and gyroids embedded in PNIPAm matrix, as well PS-PNIPAm lamellar structure, to probe release in aqueous solution below and above the cloud point temperature (CPT) of PNIPAm. The release was detected by fluorescence emission given by the probe binding to bovine serum albumin. Also, the colloidal behavior of hydrogel nanoparticles at varying temperatures were examined by scattering method. The probe release was faster below than above the CPT from all the morphologies of which gyroidal morphology showed the highest release. Colloidal behavior varied from single to moderately aggregated particles in order spheres-gyroids-lamellar. Hydrogel nanoparticles with tunable intra particle self-assembled morphologies can be utilized designing carrier systems for drug delivery and diagnostics.