ИСТИНА

Nano- and microgels are soft polymer particles with a network structure which combine the properties of solid colloids, polymers and surfactants, thus offering a wide range of applications including liquid purification, emulsion stabilization, pattern formation, and most notably, targeted drug delivery [1]. In the latter context, the crucial role lies in particles’ ability to change their shape, size, softness and porosity in response to external stimuli such as temperature or pH. Here the inclusion of various functional groups allows for the absorption and release of specific "guest" molecules. Although the effectiveness of microgels has been demonstrated in both in vitro and in vivo studies for many medications, there is still a challenge in encapsulating hydrophobic drugs within the polymer network. Amphiphilic microgels, containing both hydrophilic and hydrophobic monomer units, offer a solution by forming hydrophobic domains (“pockets”) for drug accumulation while maintaining overall hydrophilicity for colloidal stability and sensitivity to external stimuli. In turn, the biodegradability of the hydrophobic pockets enables a controlled release of absorbed molecules. Despite the apparent potential of amphiphilic stimuli-responsive microgels for biomedical use, currently there are only few examples available [2-3]. This study aims to examine the properties of amphiphilic stimuli-responsive particles based on N-isopropylacrylamide and hydrophobic macromonomers. The latter is represented by biodegradable star-shaped oligo(ε-caprolactone) (starOCL) crosslinkers. Initially, an in silico synthesis of the amphiphilic networks mimicking the actual dispersion polymerization process was performed [4]. Then, the swelling behavior of the resulting particles was studied using molecular dynamics simulations. Finally, the ability to encapsulate hydrophobic guest molecules and to release them during crosslinker degradation has been demonstrated. Our results may be useful in the obtainment of biocompatible soft carriers for the efficient drug delivery.