Bevacizumab anticancer monoclonal antibody: native and denatured redox behaviour

Electrochemistry as a Powerful Tool for Investigations of Antineoplastic Agents: A Comprehensive Review

Cancer is most frequently treated with antineoplastic agents (ANAs) that are hazardous to patients undergoing chemotherapy and the healthcare workers who handle ANAs in the course of their duties. All aspects related to hazardous oncological drugs illustrate that the monitoring of ANAs is essential to minimize the risks associated with these drugs. Among all analytical techniques used to test ANAs, electrochemistry holds an important position. This review, for the first time, comprehensively describes the progress done in electrochemistry of ANAs by means of a variety of bare or modified (bio)sensors over the last four decades (in the period of 1982-2021). Attention is paid not only to the development of electrochemical sensing protocols of ANAs in various biological, environmental, and pharmaceutical matrices but also to achievements of electrochemical techniques in the examination of the interactions of ANAs with deoxyribonucleic acid (DNA), carcinogenic cells, biomimetic membranes, peptides, and enzymes. Other aspects, including the enantiopurity studies, differentiation between single-stranded and double-stranded DNA without using any label or tag, studies on ANAs degradation, and their pharmacokinetics, by means of electrochemical techniques are also commented. Finally, concluding remarks that underline the existence of a significant niche for the basic electrochemical research that should be filled in the future are presented.

Electrochemical evaluation of nivolumab used in cancer treatment with differential pulse voltammetry: A novel approach with single-use pencil graphite electrode

OBJECTIVES

Nivolumab is used in a treatment called immunotherapy, which helps the immune system cells to attack cancer cells. The electrochemical properties and quantification of this drug were performed using single-use pencil tips.

EVIDENCE ACQUISITION

Here, a selective voltammetric method for the determination and electrochemical characterization of Nivolumab used in cancer therapy was developed for the first time using a disposable pencil electrode by cyclic voltammetry and differential pulse voltammetry techniques. Nivolumab exhibited an anodic signal at +0.879 V (vs. Ag/AgCl) in PBS (pH 3.0, 0.02 M NaCl) medium.

RESULTS

This procedure showed a linear response in phosphate buffer solutions (pH 3.0, 0.02 M NaCl) media within the concentration range of 0.01 mg mL-1 to 0.07 mg mL-1 and limit of detection and the limit of quantification values were determined to be 2.49 μg mL-1 and 8.30 μg mL-1, respectively.

CONCLUSIONS

The developed method offers an important analytical approach for the detection and characterization of NIVO. Precisely measuring and monitoring the levels of such drugs in real sample analyses or biological samples is critical for evaluating response to treatment, optimizing treatment strategies. Therefore, the method was applied to real sample analyses. Voltammetric results developed using PG electrode were compared with UV-Vis results. It has been determined that the results obtained are compatible with each other.

Voltammetric studies and spectroscopic investigations of the interaction of an anticancer drug bevacizumab-DNA and analytical applications of disposable pencil graphite sensor

A sensitive, simple, fast electrochemical biosensor for the DNA interaction of bevacizumab (BEVA), which is used as a targeted drug in cancer treatment, was developed using the differential pulse voltammetry (DPV) technique with pencil graphite electrode (PGE). In the work, PGE was electrochemically activated in a supporting electrolyte medium of +1.4 V/60 s (PBS pH 3.0). Surface characterization of PGE was carried out by SEM, EDX, EIS, and CV techniques. Determination and electrochemical properties of BEVA were examined with CV and DPV techniques. BEVA gave a distinct analytical signal on the PGE surface at a potential of +0.90 V (vs. Ag/AgCl). In the procedure proposed in this study, BEVA gave a linear response on PGE in PBS (pH 3.0 containing 0.02 M NaCl) (0.1 mg mL-1 - 0.7 mg mL-1) with LOD and LOQ values of 0.026 mg mL-1 and 0.086 μg mL-1, respectively. BEVA was reacted with 20 μg mL-1 DNA in PBS for 150 s and analytical peak signals for adenine and guanine bases were evaluated. The interaction between BEVA-DNA was supported by UV-Vis. Absorption spectrometry and the binding constant was determined as 7.3 × 104.

Assessment of structural and functional similarity of biosimilar products: Bevacizumab as a case study

The antiangiogenic drug bevacizumab is a blockbuster therapeutic pharmaceutical product that is used to treat many different types of cancer including kidney, colon, rectum, lung, and breast cancer. As a result, multiple biosimilars have been approved across the various regulatory jurisdictions in India (>20 in number till date). The rapidly growing market and acceptance of biosimilars was the motivation to perform comparability study of bevacizumab biosimilars that are presently available in the Indian market. A comprehensive analytical and functional biosimilarity assessment has been performed to examine and compare innovator product of bevacizumab (Avastin-innovator product, Roche Products (India) Pvt Ltd) and six biosimilars that are being marketed in India (Abevmy from Mylan Pharmaceuticals Pvt Ltd, Bevazza from Lupin Ltd, Bryxta from Zydus Cadila, Krabeva from Biocon, Ivzumab from RPG Life Sciences Ltd, and Advamab from Alkem Laboratories Ltd). Physiochemical characterization of drug products was performed with respect to their primary structure (intact mass, reduced mass, peptide mapping by LC-MS), higher order structure (secondary structure by FTIR, Far-UV-CD, and tertiary structure by Near-UV-CD, intrinsic fluorescence spectroscopy), impurity profile (SE-HPLC, SEC-MALS, extrinsic fluorescence: size heterogenicity, degradation, stability; DLS: hydrodynamic radius; WCX-HPLC: charge variants analysis) and post-translational modifications by measuring reduced glycans through fluorescence dye analysis. Functional characterization was performed by SPR and cell proliferation assay. Further, chemometrics based quantitative evaluation of biosimilarity has been performed by combining the data obtained from analytical characterization platform. The analysis of the analytical, functional and chemometric results revealed significant levels of similarity, with biosimilar4 being the sole exception. Despite being within product specifications, Biosimilar4 displayed significant deviations with respect to critical quality attributes, including a lower proportion of monomer content, a larger percentage of basic charge variant species, and a lower proportion of aglycosylated glycoform.

Synthesis and electrochemical study of enzymatic graphene oxide-based nanocomposite as stable biosensor for determination of bevacizumab as a medicine in colorectal cancer in human serum and wastewater fluids

This work's goal was the fabrication of a graphene oxide-based nanocomposite biosensor for the determination of bevacizumab (BVZ) as a medicine for colorectal cancer in human serum and wastewater fluids. For the fabrication electrode, graphene oxide was electrodeposited on GCE (GO/GCE), and then DNA and monoclonal anti-bevacizumab antibodies were immobilized on the GO/GCE surface, respectively (Ab/DNA/GO/GCE). Structural characterization using XRD, SEM, and Raman spectroscopy confirmed the binding of DNA to GO nanosheets and the interaction of Ab with the DNA/GO array. Electrochemical characterization of Ab/DNA/GO/GCE using CV and DPV indicated immobilization of antibodies on DNA/GO/GCE and sensitive and selective behavior of modified electrodes for determination of BVZ. The linear range was obtained 10-1100 μg/mL, and the sensitivity and detection limit values were determined to be 0.14575 μA/μg.mL^-1 and 0.02 μg/mL, respectively. To verify the applicability of the planned sensor for determination of BVZ in human serum and wastewater fluid specimens, the outcomes of DPV measurements using Ab, DNA, GO, and GCE and the results of the Bevacizumab ELISA Kit for determination of BVZ in prepared real specimens showed good conformity between the outcomes of both analyses. Moreover, the proposed sensor showed considerable assay precision with recoveries ranging from 96.00% to 98.90% and acceptable relative standard deviations (RSDs) below 5.11%, illustrating sufficiently good sensor accuracy and validity in the determination of BVZ in prepared real specimens of human serum and wastewater fluids. These outcomes demonstrated the feasibility of the proposed BVZ sensor in clinical and environmental assay applications.

DNA-Based Electrodes and Computational Approaches on the Intercalation Study of Antitumoral Drugs

The binding between anticancer drugs and double-stranded DNA (dsDNA) is a key issue to understand their mechanism of action, and many chemical methods have been explored on this task. Molecular docking techniques successfully predict the affinity of small molecules into the DNA binding sites. In turn, various DNA-targeted drugs are electroactive; in this regard, their electrochemical behavior may change according to the nature and strength of interaction with DNA. A carbon paste electrode (CPE) modified with calf thymus ds-DNA (CPDE) and computational methods were used to evaluate the drug–DNA intercalation of doxorubicin (DOX), daunorubicin (DAU), idarubicin (IDA), dacarbazine (DAR), mitoxantrone (MIT), and methotrexate (MTX), aiming to evaluate eventual correlations. CPE and CPDE were immersed in pH 7 0.1 mM solutions of each drug with different incubation times. As expected, the CPDE response for all DNA-targeted drugs was higher than that of CPE, evidencing the drug–DNA interaction. A peak current increase of up to 10-fold was observed; the lowest increase was seen for MTX, and the highest increase for MIT. Although this increase in the sensitivity is certainly tied to preconcentration effects of DNA, the data did not agree entirely with docking studies, evidencing the participation of other factors, such as viscosity, interfacial electrostatic interactions, and coefficient of diffusion.

DNA Electrochemical Biosensors for In Situ Probing of Pharmaceutical Drug Oxidative DNA Damage

Deoxyribonucleic acid (DNA) electrochemical biosensors are devices that incorporate immobilized DNA as a molecular recognition element on the electrode surface, and enable probing in situ the oxidative DNA damage. A wide range of DNA electrochemical biosensor analytical and biotechnological applications in pharmacology are foreseen, due to their ability to determine in situ and in real-time the DNA interaction mechanisms with pharmaceutical drugs, as well as with their degradation products, redox reaction products, and metabolites, and due to their capacity to achieve quantitative electroanalytical evaluation of the drugs, with high sensitivity, short time of analysis, and low cost. This review presents the design and applications of label-free DNA electrochemical biosensors that use DNA direct electrochemical oxidation to detect oxidative DNA damage. The DNA electrochemical biosensor development, from the viewpoint of electrochemical and atomic force microscopy (AFM) characterization, and the bottom-up immobilization of DNA nanostructures at the electrode surface, are described. Applications of DNA electrochemical biosensors that enable the label-free detection of DNA interactions with pharmaceutical compounds, such as acridine derivatives, alkaloids, alkylating agents, alkylphosphocholines, antibiotics, antimetabolites, kinase inhibitors, immunomodulatory agents, metal complexes, nucleoside analogs, and phenolic compounds, which can be used in drug analysis and drug discovery, and may lead to future screening systems, are reviewed.