Bioorthogonal chemistry amplifies nanoparticle binding and enhances the sensitivity of cell detection

Abstract

Nanoparticles have emerged as key materials for biomedical applications because of their unique and tunable physical properties, multivalent targeting capability, and high cargo capacity1,2. Motivated by these properties and by current clinical needs, numerous diagnostic3–10 and therapeutic11–13 nanomaterials have recently emerged. Here we describe a novel nanoparticle targeting platform that uses a rapid, catalyst-free cycloaddition as the coupling mechanism. Antibodies against biomarkers of interest were modified with trans-cyclooctene and used as scaffolds to couple tetrazine-modified nanoparticles onto live cells. We show that the technique is fast, chemoselective, adaptable to metal nanomaterials, and scalable for biomedical use. This method also supports amplification of biomarker signals, making it superior to alternative targeting techniques including avidin/biotin.

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

“…2,3 Surface functionalization strategies have been established during recent years using standard bioconjugation techniques 4 , supramolecular or bioorthogonal chemistry 5 , or nanoparticles (NPs) such as gold 6 , which are almost readymade for coupling procedures due to their particular chemistry. Despite significant progress in the field, surface functionalization is usually achieved in a tedious process by adapting typical synthesis parameters such as reaction time, concentration or pH.…”

Rational Design of Materials Interface for Efficient Capture of Circulating Tumor Cells

“…The antibody provides sites for multiple MNP binding. Reproduced with permission 112. Copyright 2010, Macmillan Publishers Ltd. C) Typical example of the μ NMR system.…”

Bioorthogonal chemistries for nanomaterial conjugation and targeting

“…Owing to the rapid kinetics of TCO/Tz Diels-Alder cycloaddition, Haun et al adapted this chemistry for functionalizing MFNP with antibodies and compared the binding efficiency to the classic maleimide-thiol coupling [42] . The monoclonal antibodies were first decorated with one to two TCO residues via standard amine-reactive chemistry and then directly coupled to Tz-modified MFNPs.…”

“…Haun et al investigated the capabilities of the exceptionally fast TCO/Tz reaction for covalent, in situ coupling of MFNP to live cells [42] . Using monoclonal antibodies that were heavily modified with TCO for pretargeting extracellular cancer biomarkers (HER2, EGFR, EpCAM), followed by the covalent reaction of Tz-MFNP, the theory that the antibody may be large enough and the covalent linkage small enough, to promote the attachment of multiple MFNP sensors was tested (Figure 2 ).…”

“…The limited tissue sample available in FNAs, as well as the low expression levels of some proteins of interest, has prevented molecular analysis in the clinic. The bioorthogonal amplification/ μ NMR detection strategy, however, is highly sensitive and capable of accurately measuring the expression levels from sample sizes on the order of 100 -1000 cells [42,43] . It is, therefore, well-suited to address the challenges of molecular diagnosis in the clinic.…”