Biomarkers as Biomedical Bioindicators: Approaches and Techniques for the Detection, Analysis, and Validation of Novel Biomarkers of Diseases

Abstract

A biomarker is any measurable biological moiety that can be assessed and measured as a potential index of either normal or abnormal pathophysiology or pharmacological responses to some treatment regimen. Every tissue in the body has a distinct biomolecular make-up, which is known as its biomarkers, which possess particular features, viz., the levels or activities (the ability of a gene or protein to carry out a particular body function) of a gene, protein, or other biomolecules. A biomarker refers to some feature that can be objectively quantified by various biochemical samples and evaluates the exposure of an organism to normal or pathological procedures or their response to some drug interventions. An in-depth and comprehensive realization of the significance of these biomarkers becomes quite important for the efficient diagnosis of diseases and for providing the appropriate directions in case of multiple drug choices being presently available, which can benefit any patient. Presently, advancements in omics technologies have opened up new possibilities to obtain novel biomarkers of different types, employing genomic strategies, epigenetics, metabolomics, transcriptomics, lipid-based analysis, protein studies, etc. Particular biomarkers for specific diseases, their prognostic capabilities, and responses to therapeutic paradigms have been applied for screening of various normal healthy, as well as diseased, tissue or serum samples, and act as appreciable tools in pharmacology and therapeutics, etc. In this review, we have summarized various biomarker types, their classification, and monitoring and detection methods and strategies. Various analytical techniques and approaches of biomarkers have also been described along with various clinically applicable biomarker sensing techniques which have been developed in the recent past. A section has also been dedicated to the latest trends in the formulation and designing of nanotechnology-based biomarker sensing and detection developments in this field.

Keywords: biomarkers; biomolecules; nanotechnology; nucleic acids; omics; proteins.

Figure 2

Circulating biomarkers can be employed for disease diagnosis, monitoring, and therapy (adapted from [40]).

Figure 4

A versatile microparticle-based immuno-aggregation assay for macromolecular biomarker detection and quantification (adapted with permission from [83]).

Figure 5

Various approaches for biomarker detection and analysis assays (adapted from [93]).

Figure 1

Classification of various biomarkers implicated in health and diseases.

Figure 3

Predictive cancer biomarkers are helpful in providing more effective therapeutic outcomes in personalized cancer therapy as compared to the conventional therapy (adapted with permission from [42]).

Figure 6

Surface functionalization of sensing nano-biomaterials leads to more specific substrate binding and, further, results in enhanced sensitivity of detection.

Figure 7

Paradigms and steps used in the sensing and detection of clinically significant bio-macromolecules for disease diagnosis. (A) DNA-based nanosensors fabrication by immobilizing acpc PNA (D-prolyl-2-aminocyclopentanecarboxylic acid—peptide nucleic acid) via covalent bond; (B) Surface tethering of the cellulose-based sensor for the identification of Esterase enzyme by using the flu orogen; (C) Illustration of bilirubin sensor using photoluminescent carbon dot sensing probes; (D) Fabrication pattern of the paper-based biosensor for determination of glycoprotein; (E) Schematic representation of a fabrication and detection method of ALP biosensor (adapted with permission from [124]).