The objective of this study is to develop a novel biocompatible amphiphilic drug delivery for hydrophobic drugs, chitosan (CS) was grafted to a series of hydrophobic amino acids including l-alanine (A), l-proline (P), and l-tryptophan (W) by carbodiimide mediated coupling reaction. Chemical characteristics of the modified polymers were determined and confirmed by FT-IR, 1H NMR, and UV-vis spectroscopy and the degree of substitution was quantified by elemental analysis. The modified polymers were used to form amphiphilic chitosan nanocarriers (ACNs) by the conventional self-assembly method using ultrasound technique. The morphology and the size of ACNs were analyzed by scanning electron microscope (SEM) and Dynamic light scattering (DLS). The sizes of spherical ACNs analyzed by SEM were obviously smaller than those of determined by DLS. The ACNs effectively surrounded the hydrophobic model drug, letrozole (LTZ), and demonstrated different encapsulation efficiencies (EE), loading capacities (LC), and controlled drug release profiles. The characteristics of ACNs and the mechanism of drug encapsulation were confirmed by molecular modeling method. The modeling of the structures of LTZ, profiles of A, P, and W grafted onto CS and the wrapping process around LTZ was performed by quantum mechanics (QM) methods. There was a good agreement between the experimental and theoretical results. The cell viability was also evaluated in two cell lines compared with free drug by MTT assay. The hydrophobic portion effects on ACNs' characteristics and the proper selection of amino acid demonstrate a promising potential for drug delivery vector.

Novel reduction-responsive hyaluronic acid–chitosan–lipoic acid nanoparticles (HACSLA-NPs) were designed and synthesized for effective treatment of breast cancer by targeting Cluster of Differentiation 44 (CD44)-overexpressing cells and reduction-triggered 17α-Methyltestosterone (MT) release for systemic delivery. The effectiveness of these nanoparticles was investigated by different assays, including release rate, 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT), lactate dehydrogenase (LDH), caspase-3 activity, Rhodamine 123 (RH-123), and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). In vitro experiments revealed that Methyltestosterone/Hyaluronic acid–chitosan–lipoic acid nanoparticles (MT/HACSLA-NPs) illustrated a sustained drug release in the absence of glutathione (GSH), while the presence of GSH led to fast MT release. HACSLA-NPs also showed high cellular internalization via CD44 receptors, quick drug release inside the cells, and amended cytotoxicity against positive CD44 BT-20 breast cancer cell line as opposed to negative CD44, Michigan Cancer Foundation-7 (MCF-7) cell line. These findings supported that these novel reduction-responsive NPs can be promising candidates for efficient targeted delivery of therapeutics in cancer therapy.

Heat-shock protein A2 (HSPA2) is a testis-specific member of the HSP70 family known to correlate with sperm maturity, function and fertility. The aim of this study was to compare expression of HSPA2 in fertile and infertile individuals using a recently marketed highly purified polyclonal antibody. Thus, after analysing sperm concentration, motility and morphology in semen sample of 49 individuals with male factor infertility and 47 fertile individuals according to World Health Organization guidelines, we evaluated HSPA2 by microscope florescence, flow cytometry, Western blot and RT-PCR. We observed higher percentage of sperm expressing HSPA2 in anterior and equatorial regions in fertile than infertile individuals by microscope fluorescence. Percentage of sperm expressing HSPA2 in two conditions (fixed permeabilised and capacitated) by flow cytometry showed that percentage of HSPA2-positive sperm in fixed permeabilised and also capacitated samples was significantly different between fertile and infertile individuals. Western blot analysis of HSPA2 in semen samples revealed high variation within the fertile and infertile population. The results of RT-PCR revealed higher expression of HSPA2 in the fertile compared to infertile individuals, but this difference was not significant. According to the results, we suggest that HSPA2 expression is heterogeneously expressed on different part of fixed permeabilised sperm and its expression is significantly higher in fertile compared to infertile individuals. The surface expression of this protein significantly increases following capacitation in both fertile and infertile individuals. HSPA2 expression significantly correlates with sperm concentration and morphology. Therefore, aberrant HSPA2 expression may play an important role in capacitation and fertilisation processes.