An investigation of the interactions between bio-polymeric nanoparticles (NPs) and the RAW 264.7 mouse murine macrophage cell line has been presented. The cell viability, immunological response, and endocytosis efficiency of NPs were studied. Biopolymeric NPs were synthesized from a nanoemulsion using the phase inversion composition (PIC) technique. The two types of biopolymeric NPs that were obtained consisted of a biocompatible polymer, polycaprolactone (PCL), either with or without its copolymer with poly(ethylene glycol) (PCL-b-PEG). Both types of synthesized PCL NPs passed the first in vitro quality assessments as potential drug nanocarriers. Non-pegylated PCL NPs were internalized more effectively and the clathrin-mediated pathway was involved in that process. The investigated NPs did not affect the viability of the cells and did not elicit an immune response in the RAW 264.7 cells (neither a significant increase in the expression of genes encoding pro-inflammatory cytokines nor NO (nitric oxide) production were observed). It may be concluded that the synthesized NPs are promising candidates as nanocarriers of therapeutic compounds.

Clozapine (CLO), an atypical antipsychotic used in the clinic for treatment of schizophrenia, has a well-known efficacy, but its general use in clinical practice is limited because of the risk of serious side effects. Therefore, in the present work, we focused on the encapsulation of CLO into polymeric polycaprolactone nanoparticles (PCL NPs) and studies of interactions of this nanoformulation with model cells. Two types of clozapine PCL NPs (CLO-PCL NPs), pegylated and non-pegylated, were obtained by nanoemulsion templating method. The complex interactions of these NPs with three model cell lines (HEK 293, human embryonic kidney cell line; RAW 264.7, murine macrophage cell line; hCMEC/D3, model of blood-brain barrier, BBB) were studied. Cell viability, cellular uptake of NPs, NO release, expression of proinflammatory agents and transcytosis experiments were performed. Pegylated CLO-PCL NPs showed better results in the tests performed in the present study, in comparison to non-pegylated ones: they are not toxic to model cells; pegylated outer surface protected from their fast uptake by macrophages; they were not immunogenic; transcytosis experiments pointed to their ability to cross a model BBB. The results obtained in the present study indicate that pegylated CLO-PCL NPs are promising carrier for antipsychotic drugs directed to cross BBB. The experiments were conducted using only in vitro models but they provide valuable data in the field of nanotechnology which can be used in novel molecular pharmacology.