Delivery of Chlorambucil to the Brain Using Surface Modified Solid Lipid Nanoparticles

The delivery of drugs to the brain in the therapy of diseases of the central nervous system (CNS) remains a continuing challenge because of the lack of delivery systems that can cross the blood-brain barrier (BBB). Therefore, there is a need to develop an innovative delivery method for the treatment of CNS diseases. Thus, we have investigated the interaction of γ-aminobutyric acid (GABA) and S-(-)-γ-amino-α-hydroxybutyric acid (GAHBA) with the GABA receptor by performing a docking study. Both GABA and GAHBA show comparable binding affinities toward the receptor. In this study, we developed surface-modified solid lipid nanoparticles (SLNs) using GAHBA-derived lipids that can cross the BBB. CLB-loaded SLNs were characterized by a number of methods including differential scanning calorimetry, dynamic light scattering, UV-vis spectroscopy, and transmission electron microscopy. The blank and CLB-loaded SLN suspensions were found to exhibit good storage stability. Also, the SLNs showed a higher encapsulation efficiency for CLB drugs. In vitro release kinetics of CLB at physiological temperature was also investigated. The results of the in vitro cell cytotoxicity assay and flow cytometry studies in the human glioma U87MG cell line and human prostate cancer PC3 cell line suggested a higher efficacy of the GAHBA-modified CLB-loaded SLNs in U87MG cells. The transcription level of GABA receptor expression in the target organ and cell line was analyzed by a reverse transcription polymerase chain reaction study. The in vivo biodistribution and brain uptake in C57BL6 mice and SPECT/CT imaging in Wistar rats investigated using ^99mTc-labeled SLN and autoradiography suggest that the SLNs have an increasing brain uptake. We have demonstrated the delivery of the anticancer drug chlorambucil (CLB) to glioma.