A Critical Review of Biological Properties, Delivery Systems and Analytical/Bioanalytical Methods for Determination of Bevacizumab.

Bevacizumab is a chimeric monoclonal human-murine antibody originated from murine monoclonal antibody (muMAb A4.6.1) with the human immunoglobulin IgG1. BVZ binds the extracellular portion of vascular endothelial growth factor receptors (VEGFR), which have tyrosine kinase activity. The mechanism of action of BVZ involves binding to VEGFR, Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), inducing homodimerization of two receptor subunits, and, consequently, autophosphorylation of their tyrosine kinase domains located inside the cytoplasm. With the advent of nanostructured systems it is increasingly necessary to look for safe analytical methods, ensuring the reliability of the results obtained by them, becoming essential to ensure the quality of medicines. In this work, the incorporation of bevacizumab in to different drug delivery systems was presented. Moreover, detailed investigation was performed about methods for qualitative and quantitative analyses of bevacizumab, including, biological fluids, and drug delivery systems, were investigated. Most recently high performance liquid chromatography coupled with various detectors, liquid chromatography, mass spectrometry and ELISA were used for this purpose. Thus, this review was performed to evaluate the benefits of bevacizumab carried by nanostructured systems and the analytical methods available for detection and quantification of these drugs.

A Review of Properties, Delivery Systems and Analytical Methods for the Characterization of Monomeric Glycoprotein Transferrin.

Transferrin is a protein involved in iron uptake by cells and has been identified as a potential target for directing drug-loaded nanoparticles for cancer treatment and diagnosis. Most methods for conjugation of transferrin and nanoparticles involve the formation of a thioeter bond between thiolated transferrin and maleimide-containing nanoparticle. For nanoparticle development, it is important to perform a thorough physicochemical characterization, including quantification of the amount of transferrin functionalizing the delivery system. Thus, following the transferrin and nanoparticle chemical conjugation, an analytical method is need for transferrin quantification. Altogether, we revised both physicochemical and pharmacokinetics transferrin characteristics, the aspects of iron transport after interaction with transferrin, the development of transferrin targeted-nanoparticles, highlighting both their composition, synthesis methods and in vitro/in vivo evaluation. Furthermore, we addressed the analytical methods employed in protein quantification, including spectrophotometric/colorimetric, immunoassays, electrophoretic and chromatographic techniques used to identify and/or quantify of transferrin in biological matrices and drug delivery systems.

EGFR-targeted immunoliposomes efficiently deliver docetaxel to prostate cancer cells.

Prostate cancer is the second cause of cancer death in men worldwide. Docetaxel (DTX), an antimitotic drug, is widely used for the treatment of metastatic prostate cancer patients. Taxotere® is a commercial DTX formulation. It contains a polysorbate 80 surfactant to improve DTX aqueous solubility, which has been associated with hypersensitivity reactions in patients. Liposomes have been used as promising delivery systems for a range of hydrophobic drugs, such as DTX, offering improved drug water solubility and biocompatibility, without compromising its anticancer activity. Herein, DTX-loaded liposomes were developed using the Box-Behnken factorial design. The optimized formulation was nano-sized, homogenous in size (67.47 nm) with high DTX encapsulation efficiency (99.95 %). The encapsulated DTX was in a soluble amorphous state, which was slowly released. Next, to increase the liposomes selectivity to prostate cancer cells, cetuximab, an anti-EGFR monoclonal antibody. was successfully conjugated to the surface of liposomes, without compromising cetuximab protein structure and stability. As expected, our results showed higher cellular uptake and toxicity of immunoliposomes, compared to non-targeted liposomes, in DU145 (EGFR-overxpressing) prostate cancer cells. To the best of our knowledge, this is the first report of engineering EGFR-targeted liposomes to enhance the selectivity of DTX delivery to EGFR-positive prostate cancer cells.

A Critical Review of Properties and Analytical/Bioanalytical Methods for Characterization of Cetuximab.

Cetuximab (CTX) is a chimeric monoclonal antibody (mAb) able to selectively bind to the epidermal growth factor receptor (EGFR), resulting in inhibition of EGF linkage and phosphorylation cascade interruption. As a result, it is able to prevent cell proliferation, angiogenesis and metastasis, usually related to cancer malignization. As the EGFR is overexpressed in many human tumors, its use has been approved by FDA since 2006. Clinical use of CTX has been proved to cause skin rash which is related to the better prognosis. Thus, currently strategies also focus on the development of safe and effective drug delivery systems and on quantification methods for CTX in a variety of matrices. Based on the challenges to quantify CTX, immunoassays, spectrophotometric assays, electrophoretic assays and chromatographic assays are under study. Among them, the spectrophotometric/colorimetric techniques, used in near 32% of the papers investigated, followed by chromatographic techniques and immunoassay methods, such as enzyme-linked immunosorbent assay (ELISA), used in 29% and 26%, respectively, and electrophoretic techniques used in near 13%. Herein, we will describe and discuss CTX main aspects and highlight the main quantification methods that are currently used for its quantification in different matrices.

A Critical Review of Properties and Analytical Methods for the Determination of Docetaxel in Biological and Pharmaceutical Matrices.

Docetaxel (DTX) is an antineoplastic agent of the second generation of the taxoid family. It is a semi-synthetic drug prepared from a precursor extracted of the plant Taxus baccata. The commercial formulation of DTX, Taxotere®, employs the surfactant polysorbate 80, due to the low water solubility of the drug, causing several side effects. Therefore, there is a need to develop delivery systems to reduce the side effects of DTX. In addition, this drug has been qualitative and quantitatively analyzed in pharmaceutical formulations and biological samples. Thus, several techniques and analytical methods have been reported with the aim of optimizing the analytical signal, increasing sensitivity, selectivity and reducing the effects of interference. Herein, we highlight immunoassay, capillary electrophoresis and chromatographic methods. This review presents a summary of physicochemical and pharmacokinetics properties, mechanisms of action, drug delivery systems and analytical methods used in quantification of DTX in diverse matrices such as blood, plasma, oral fluid, urine, carcinoma cells, pharmaceutical formulations and delivery systems.