In drug delivery science, brain delivery is one of the most important challenges because of the low efficiency of the available treatments. Nowadays, shuttle peptides have attracted more attention because of lower price, reduced immunity, and increased chemical capability. Glutathione (GSH) is one of the blood−brain barrier (BBB) shuttle peptides that has reached the most progressive steps in the path toward clinical application. This project discovered the possibility of GSH-conjugated IONPs as an MRI-monitored paclitaxel (PTX) delivery vehicle across the BBB using BALB/c mouse model. Synthesized shuttle peptide-conjugated nanoparticles were tracked over a certain time by MRI. A one-pot method was used for preparation of IONPs@Asp to form functionalized nanoparticles with two functional groups for linkage of PTX, PEG, and then GSH on the surface of nanoparticles. Afterward, they were analyzed by XRD, TGA, FTIR, TEM, VSM, and DLS techniques. In addition, histological study were performed on the key organs. Here, we exhibit that (1) IONPs@Asp are stable and nontoxic to different cells; (2) conjugation of GSH to nanoparticles promotes their internalization to brain in vivo; (3) final formulation

In this study, magnetic nanoparticles (MNPs) coated with L-aspartic acid (F-Asp NPs) were synthesized through a co-precipitation method and conjugated with paclitaxel (PTX) (F-Asp-PTX NPs) by esterification reaction between the carboxylic acid end groups on MNPs surface and the hydroxyl groups of the PTX and studied its cytotoxic effect in vitro. The successful conjugating of PTX onto the nanoparticles (NPs) was confirmed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM) techniques. The results showed that the average size was 46.11 ± 7.8 (mean ± SD (n = 25)) nm. The cytotoxicity of void of PTX and F-Asp-PTX NPs were compared to each other by MTT assay of the treated MCF-7 cell line. The F-Asp-PTX NPs showed pH-dependent drug release behavior. These studies specify that F-Asp-PTX NPs have a very remarkable anticancer effect, for breast cancer cell line.