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Immune Systems, Molecular Diagnostics, and Bionanotechnology
Published in Anil Kumar Anal, Bionanotechnology, 2018
Bioconjugation is the process of bonding biologically active molecules to nanoparticles either by biological or chemical process for enhancing the stability, functionality, and biocompatibility. The physical means of conjugating gold nanoparticles (AuNPs) with biomolecules such as monoclonal antibody include three different mechanisms, that is, (1) ionic interaction, (2) hydrophobic interaction, and (3) dative binding. Chemical bioconjugation method involves the following: (1) chemisorption, (2) bifunctional linker, and (3) adapter. For bioconjugation, both covalent and noncovalent immobilization modes are being used. During electrostatic and hydrophobic interaction, antibodies are nonspecifically adsorbed onto gold (noncovalent mode), whereas during dative binding and chemical bioconjugation method, antibodies bind onto the surface of AuNPs by covalent mode. The different mechanism for bioconjugation of antibodies and nanoparticles is summarized in Table 5.1.
Aptamers in Medical Diagnosis
Published in Rakesh N. Veedu, Aptamers, 2017
Veli Cengiz Ozalp, Murat Kavruk, Ozlem Dilek, Abdullah Tahir Bayrac
Aptamers can readily be modified with a variety of chemical groups, which provides the subsequent attachment of an aptamer to various formats of sensors. Bioconjugation is a chemical strategy for covalent modification of biomolecules. Bioconjugation strategies are essential for the discovery of function of biomolecules using chemoselective reactions that are functional under physiological conditions [36, 79]. For example, introduction of traditional functional groups within biomolecules has provided convenient sites for highly chemoselective modification, leading to their immobilization on surfaces and labeling with small molecules. Novel methods have recently been discovered for site-specific covalent conjugations of proteins, aptamers, DNA, RNA, and carbohydrates [36]. Traditional strategies for covalent bioconjugation include the introduction of nonnatural functional groups into biomolecules, followed by site-specific embedding on surfaces via selective chemical reaction. However, poor reactivity has always been the major disadvantage of traditional methods and such chemical modifications have resulted in loss of the biological function of the target biomolecule. Due to high specificity and minimal perturbation on biomolecules, site-specific bioconjugation is favorable to random conjugation methods.
Controlled Wet Chemical Synthesis of Multifunctional Nanomaterials: Current Status and Future Possibility
Published in Surender Kumar Sharma, Nanohybrids in Environmental & Biomedical Applications, 2019
Navadeep Shrivastava, Surender Kumar Sharma
The major challenge in bioconjugation is to maintain the functionality of the biomolecule. In addition, the orientation of the attached molecule is critical to ensure access to the analyte recognition site. Favorable binding orientation affects the assay performance significantly (Zhang & Meyerhoff, 2006). After the conjugation step, the excess biomolecules should be removed thoroughly without losing the nanoparticle conjugates, and the success of the bioconjugation needs to be confirmed using nuclear magnetic resonance (NMR) and Fourier transformation infrared (FTIR) techniques. Several works of bioconjugation with different types of nanoparticles can be found in review articles (Sperling & Parak, 2010; Sapsford et al., 2011; Massey and Russ, 2017).
Biocompatible conjugation for biodegradable hydrogels as drug and cell scaffolds
Published in Cogent Engineering, 2020
The Diels-Alder reaction in aqueous environments, which involves a highly selective [4 + 2] cycloaddition reaction between a diene and a dienophile, is diverse in scope and efficient in reactivity, results in very high yields, produces no byproducts, and occurs under mild reaction conditions (Dantas De Araújo et al., 2006; Jia et al., 2015; Sun et al., 2006; H. Tan et al., 2011; Tiwari & Kumar, 2006). The compatibility of aqueous Diels-Alder chemistry with biomolecules has been exploited elegantly in the bioconjugation of protein, peptides and oligonucleotides, which were site-specific without the interference of the many functional groups present in the polysaccharide backbone (Hill et al., 2001; Kim et al., 2005; Shi et al., 2009, 2007; Tona & Häner, 2005). Given the high specificity and efficiency, the success of aqueous Diels-Alder chemistry in biomolecule conjugation and immobilization may be extended to the synthesis of biodegradable hydrogels. The aqueous Diels-Alder cycloaddition reaction was used as a new methodology to conjugate a polysaccharide hydrogel, which provides a competitive alternative to conventional methodologies to prepare biodegradable hydrogels. For example, a polysaccharide derivative hydrogel with novel structures has been developed via aqueous Diels-Alder cycloaddition reaction of bio-conjugation that specifically allows for biopharmaceutical delivery (H. Tan et al., 2011). Hydrogel precursors were designed with furan groups (diene) on the outer PEG, corona that are accessible for reaction with maleimide (dienophile) functionalized HA derivatives in an aqueous environment at 37°C (Figure 6a).
Investigation of the arsenic(V) retention performance of the nano-sorbent (M-TACA) synthesized by click chemistry
Published in Journal of Dispersion Science and Technology, 2023
Bilsen Tural, Erdal Ertaş, Servet Tural
The chemistry of the reactions used to attach selective functional ligands such as NMDG to the surface of MNPs is very important. In recent years, click chemistry, which is a fast, simple, easy to purify, versatile, region-specific and high yield coupling reaction, has been used in this direction. Click chemistry is a term conceived by K. B. Sharpless in 1998 and fully defined in 2001[18] and has become a very popular topic ever since. Click chemistry provides an easy approach to bond highly functional groups to the surface of solid support.[19] In general, the 1,3-dipolar azide/alkyne cyclo-reaction is a reaction between terminal alkynes and azides resulting in 1,2,3-triazoles.[20] 1,2,3-Triazoles are a class of biologically important compounds and are found as scaffolds in many natural products.[21] Thus, triazoles occupy an important place in the total synthesis of natural products by "click reaction," as a safe and light connection framework. In addition, it is very useful due to the highly stable and aromatic nature of the triazole ring with large dipole moment combined with its hydrogen bonding ability.[22] Click reactions are applied in many fields such as organic synthesis,[23] bioconjugation,[24] drug development,[25] polymer[26] and materials science[27] and nanotechnology.[28]
Overview of the application of inorganic nanomaterials in breast cancer diagnosis
Published in Inorganic and Nano-Metal Chemistry, 2022
Asghar Ashrafi Hafez, Ahmad Salimi, Zhaleh Jamali, Mohammad Shabani, Hiva Sheikhghaderi
In summary, this article provides a comprehensive review of recent advances in some novel methods based on inorganic nanomaterials for the diagnosis of the breast cancer. In other words, we reviewed the modern methods compared with the traditional diagnostic technique where approaches based on inorganic nanomaterials could be improved the traditional technique for the diagnosis of the breast cancer. Generally, the manipulation of structure and size, as well as surface modification of inorganic nanoparticle, could increase their efficiency in diagnostic techniques based on imaging. Accordingly, surface modification of inorganic nanomaterials is critical for obtaining appropriate surface functionality for bioconjugation and improvement of their aqueous dispersibility. Since bioconjugation of inorganic nanomaterials has a remarkable impact on targeting to the diagnosis of the current location of breast cancer, therefore, the increase of conspicuity and cancer delineation, the application of inorganic nanomaterial in molecular imaging is promising. For instance, many types of inorganic nanomaterials were employed as diagnostic tools for the breast cancer such as Au nanostructure, QDs nanoparticles, IONPs and core-shell nanomaterials. To emphasize, many reports were demonstrated that applied inorganic nanomaterials had a positive effect on the breast cancer diagnosis within both in vitro and in vivo studies phases. However, there are many questions about biocompatibility, long-term cytotoxicity and exact molecular display that should be answered. As a result, more comprehensive research is necessary for clinical applications of inorganic nanomaterials in the diagnosis of the breast cancer. In addition, using the standard method based on a suitable model for preclinical studies can develop the number of inorganic nanomaterials targeted at clinical application. Despite the fact that the significant progress has been made in in vitro and in vivo phase, there are many problems to obtaining FDA approvals. To sum up, nanotechnology by focusing on targeted inorganic nanomaterial is able not only to improve the mentioned disadvantages of classic imaging methods but also to open new perspectives related to exact and early diagnosis of the breast cancer for preventing death in the women.