In this study, it was aimed to investigate characteristics and intracellular delivery of two different-sized PLGA nanoparticles in ouzo region by considering number of nanoparticles. To determine the effect of formulation parameters on average particle size, Dil labeled nanoparticles were prepared using a three-factor, two-level full factorial statistical experimental design. PLGA (230.8 ± 4.32 nm) and PLGA (157.9 ± 6.16 nm) nanoparticles were obtained by altering polymer amount based on experimental design results and characterized. Same number of PLGA and PLGA nanoparticles per cell were applied onto HEK293 cells; then, cytotoxicity, uptake kinetics and mechanism were evaluated by flow cytometry and fluorescent microscopy. Also same weight of PLGA and PLGA nanoparticles were applied and cellular uptake of these nanoparticles was evaluated. It was found that PLGA nanoparticles had higher encapsulation efficiency and slower dye release compared to PLGA nanoparticles. When they were applied at same counts per cell, PLGA nanoparticles displayed faster and higher intracellular dye transfer than PLGA nanoparticles. On the other hand, PLGA appeared to be a more effective vehicle than PLGA when applied at the same weight concentration. It was also shown that for both nanoparticles, HEK293 cells employed macropinocytic, caveolae- and clathrin-mediated endocytic pathways.

Malignant gliomas are highly lethal. Delivering chemotherapeutic drugs to the brain in sufficient concentration is the major limitation in their treatment due to the blood-brain barrier (BBB). Drug delivery systems may overcome this limitation and can improve the transportation through the BBB. Paclitaxel is an antimicrotubule agent with effective anticancer activity but limited BBB permeability. R-Flurbiprofen is a nonsteroidal antienflammatory drug and has potential anticancer activity. Accordingly, we designed an approach combining Rflurbiprofen and paclitaxel and positively-charged chitosan-modified poly-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) and to transport them to glioma tissue. NPs were characterized and, cytotoxicity and cellular uptake studies were carried out in vitro. The in vivo efficacy of the combination and formulations were evaluated using a rat RG2 glioma tumor model. Polyethylene glycol (PEG) modified and chitosan-coated PLGA NPs demonstrated efficient cytotoxic activity and were internalized by the tumor cells in RG2 cell culture. In vivo studies showed that the chitosan-coated and PEGylated NPs loaded with paclitaxel and R-flurbiprofen exhibited significantly higher therapeutic activity against glioma. In conclusion, PLGA NPs can efficiently carry their payloads to glioma tissue and the combined use of anticancer and anti-inflammatory drugs may exert additional anti-tumor activity.

The blood-brain barrier (BBB) is the major problem for the treatment of central nervous system diseases. A previous study from our group showed that the brain-targeted chitosan nanoparticles-loaded with large peptide moieties can rapidly cross the barrier and provide neuroprotection. The present study aims to determine the efficacy of the brain-targeted chitosan nanoparticles' uptake by the human BBB cerebral microvessel endothelial cells (hCMECs) and to investigate the underlying mechanisms for enhanced cellular entry. Fluorescently labelled nanoparticles either conjugated with antibodies recognising human transferrin receptor (anti-TfR mAb) or not were prepared, characterised and their interaction with cerebral endothelial cells was evaluated. The antibody decoration of chitosan nanoparticles significantly increased their entry into hCMEC/D3 cell line. Inhibition of cellular uptake by chlorpromazine indicated that the anti-TfR mAb-conjugated nanoparticles were preferentially cell internalised through receptor-mediated endocytosis pathway. Alternatively, as primarily observed with control chitosan nanoparticles, aggregation of nanoparticles may also have induced macropinocytosis.