Bioorthogonal Reactions Research Articles

Living Artificial Skin: Photosensitizer and Cell Sandwiched Bacterial Cellulose for Chronic Wound Healing.

Chronic wounds pose a significant global public health challenge due to their suboptimal treatment efficacy caused by bacterial infections and micro-circulatory disturbances. Inspired by the bio-functionality of natural skin, we bioengineered an artificial skin (HV@BC@TBG) with bacterial cellulose (BC) sandwiched between photosensitizers (PS) and functionalized living cells. Glucose-modified PS (TBG) and vascular endothelial growth factor (VEGF)-functionalized living cells (HV) were successively modified on each side of BC through biological metabolism and bio-orthogonal reaction. As the outermost layer, the TBG layer could generate reactive oxygen species (ROS) upon light illumination to efficiently combat bacterial infections. The HV layer was the inner layer near the diabetic wound, which served as a living factory to continuously secrete VEGF to accelerate wound repair by promoting fibroblast proliferation and angiogenesis. The sandwiched structural artificial skin HV@BC@TBG was non-toxic, biocompatible, and demonstrated its ability to significantly accelerate the healing process of infected diabetic wounds, rendering it a promising next-generation medical therapy for chronic wound management. This article is protected by copyright. All rights reserved.

Site-Specific Conjugation of Bottlebrush Polymers to Therapeutic Protein via Bioorthogonal Chemistry.

Achieving efficient and site-specific conjugation of therapeutic protein to polymer is crucial to augment their applicability in the realms of biomedicine by improving their stability and enzymatic activity. In this study, we exploited tetrazine bioorthogonal chemistry to achieve the site-specific conjugation of bottlebrush polymers to urate oxidase (UOX), a therapeutic protein for gout treatment. An azido-functionalized zwitterionic bottlebrush polymer (N3-ZBP) using a "grafting-from" strategy involving RAFT and ATRP methods was synthesized, and a trans-cyclooctene (TCO) moiety was introduced at the polymer end through the strain-promoted azide-alkyne click (SPAAC) reaction. The subsequent coupling between TCO-incorporated bottlebrush polymer and tetrazine-labeled UOX using a fast and safe bioorthogonal reaction, inverse electron demand Diels-Alder (IEDDA), led to the formation of UOX-ZBP conjugates with a 52% yield. Importantly, the enzymatic activity of UOX remained unaffected following polymer conjugation, suggesting a minimal change in the folded structure of UOX. Moreover, UOX-ZBP conjugates exhibited enhanced proteolytic resistance and reduced antibody binding, compared to UOX-wild type. Overall, the present findings reveal an efficient and straightforward route for synthesizing protein-bottlebrush polymer conjugates without compromising the enzymatic activity while substantially reducing proteolytic degradation and antibody binding.

An all-in-one tetrazine reagent for cysteine-selective labeling and bioorthogonal activable prodrug construction

The prodrug design strategy offers a potent solution for improving therapeutic index and expanding drug targets. However, current prodrug activation designs are mainly responsive to endogenous stimuli, resulting in unintended drug release and systemic toxicity. In this study, we introduce 3-vinyl-6-oxymethyl-tetrazine (voTz) as an all-in-one reagent for modular preparation of tetrazine-caged prodrugs and chemoselective labeling peptides to produce bioorthogonal activable peptide-prodrug conjugates. These stable prodrugs can selectively bind to target cells, facilitating cellular uptake. Subsequent bioorthogonal cleavage reactions trigger prodrug activation, significantly boosting potency against tumor cells while maintaining exceptional off-target safety for normal cells. In vivo studies demonstrate the therapeutic efficacy and safety of this prodrug design approach. Given the broad applicability of functional groups and labeling versatility with voTz, we foresee that this strategy will offer a versatile solution to enhance the therapeutic range of cytotoxic agents and facilitate the development of bioorthogonal activatable biopharmaceuticals and biomaterials.

Cyclopropenes as Chemical Reporters for Dual Bioorthogonal and Orthogonal Metabolic Labelling of DNA

Dual bioorthogonal labeling enables the investigation and understanding of interactions in the biological environment that are not accessible by a single label. However, applying two bioorthogonal reactions in the same environment remains challenging due to cross‐reactivity. We developed a pair of two differently modified 2’‑deoxynucleosides that solved this issue for dual and orthogonal labeling of DNA. Inverse‐electron demand Diels‐Alder and photoclick reactions were combined to attach two different fluorogenic labels to genomic DNA in cells. Using a small synthetic library of 1‐ and 3‐methylcyclopropenyl‐modified 2’‑deoxynucleosides, two 2’‐deoxyuridines were identified to be the fastest‐reacting ones for each of the two bioorthogonal reactions. Their orthogonal reactivity could be evidenced in vitro. Primer extension experiments were performed with both 2‘‑deoxyuridines investigating their replication properties as substitutes for thymidine and evaluating subsequent labeling reactions on the DNA level. Finally, dual, orthogonal and metabolic fluorescent labeling of genomic DNA was demonstrated in HeLa cells. An experimental procedure was developed combining intracellular transport and metabolic DNA incorporation of the two 2’‐deoxyuridines with the subsequent dual bioorthogonal labeling using a fluorogenic cyanine‐styryl tetrazine and a fluorogenic pyrene‐tetrazole. These results are fundamental for advanced metabolic labeling strategies for nucleic acids in the future, especially for live cell experiments.

Development of Biocompatible Cu(I)-Microdevices for Bioorthogonal Uncaging and Click Reactions.

Transition-metal-catalysed bioorthogonal reactions emerged a decade ago as a novel strategy to implement spatiotemporal control over enzymatic functions and pharmacological interventions. The use of this methodology in experimental therapy is driven by the ambition of improving the tolerability and PK properties of clinically-used therapeutic agents. The preclinical potential of bioorthogonal catalysis has been validated in vitro and in vivo with the in situ generation of a broad range of drugs, including cytotoxic agents, anti-inflammatory drugs and anxiolytics. In this article, we report our investigations towards the preparation of solid-supported Cu(I)-microdevices and their application in bioorthogonal uncaging and click reactions. A range of ligand-functionalized polymeric devices and off-on Cu(I)-sensitive sensors were developed and tested under conditions compatible with life. Last, we present a preliminary exploration of their use for the synthesis of PROTACs through CuAAC assembly of two heterofunctional mating units.

A Synthetic Strategy toward S-, N-, and O-Heterocyclooctynes Facilitates Bioconjugation Using Multifunctional Handles.

Over the past two decades, the introduction of bioorthogonal reactions has transformed the ways in which chemoselective labeling, isolation, imaging, and drug delivery are carried out in a complex biological milieu. A key feature of a good bioorthogonal probe is the ease with which it can be attached to a target compound through bioconjugation. This paper describes the expansion of the utility of a class of unique S-, N-, and O-containing heterocyclooctynes (SNO-OCTs), which show chemoselective reactivity with type I and type II dipoles and divergent reactivities in response to electronic tuning of the alkyne. Currently, bioconjugation of SNO-OCTs to a desired target is achieved through an inconvenient aryl or amide linker at the sulfamate nitrogen. Herein, a new synthetic approach toward general SNO-OCT scaffolds is demonstrated that enables the installation of functional handles at both propargylic carbons of the heterocycloalkyne. This capability increases the utility of SNO-OCTs as labeling reagents through the design of bifunctional bioorthogonal probes with expanded capabilities. NMR kinetics also revealed up to sixfold improvement in cycloaddition rates of new analogues compared to first-generation SNO-OCTs.

Bioactive Moldable Click Chemistry Polymer Cement with Nano-Hydroxyapatite and Growth Factor-Enhanced Posterolateral Spinal Fusion in a Rabbit Model.

Spinal injuries or diseases necessitate effective fusion solutions, and common clinical approaches involve autografts, allografts, and various bone matrix products, each with limitations. To address these challenges, we developed an innovative moldable click chemistry polymer cement that can be shaped by hand and self-cross-linked in situ for spinal fusion. This self-cross-linking cement, enabled by the bioorthogonal click reaction, excludes the need for toxic initiators or external energy sources. The bioactivity of the cement was promoted by incorporating nanohydroxyapatite and microspheres loaded with recombinant human bone morphogenetic protein-2 and vascular endothelial growth factor, fostering vascular induction and osteointegration. The release kinetics of growth factors, mechanical properties of the cement, and the ability of the scaffold to support in vitro cell proliferation and differentiation were evaluated. In a rabbit posterolateral spinal fusion model, the moldable cement exhibited remarkable induction of bone regeneration and effective bridging of spine vertebral bodies. This bioactive moldable click polymer cement therefore presents a promising biomaterial for spinal fusion augmentation, offering advantages in safety, ease of application, and enhanced bone regrowth.

Development and Application of Bioorthogonal Reactions for Drug Imaging and Activation

Chemical transformations compatible with biological systems serve as invaluable tools for probing biomolecules, drug compounds, and biological processes in their native environments. The complex environment of living organisms requires these reactions to be highly selective and efficient, posing a formidable challenge to the field of organic chemistry. A number of chemical reactions have recently emerged to meet this challenge, providing a diverse toolkit for researchers. This manuscript presents a comprehensive survey of current bioorthogonal reactions, emphasizing their applications in bioimaging, diagnostics, and medicine.

Single-Atom Catalysts Mediated Bioorthogonal Modulation of N6-Methyladenosine Methylation for Boosting Cancer Immunotherapy.

Bioorthogonal reactions provide a powerful tool to manipulate biological processes in their native environment. However, the transition-metal catalysts (TMCs) for bioorthogonal catalysis are limited to low atomic utilization and moderate catalytic efficiency, resulting in unsatisfactory performance in a complex physiological environment. Herein, sulfur-doped Fe single-atom catalysts with atomically dispersed and uniform active sites are fabricated to serve as potent bioorthogonal catalysts (denoted as Fe-SA), which provide a powerful tool for in situ manipulation of cellular biological processes. As a proof of concept, the N6-methyladensoine (m6A) methylation in macrophages is selectively regulated by the mannose-modified Fe-SA nanocatalysts (denoted as Fe-SA@Man NCs) for potent cancer immunotherapy. Particularly, the agonist prodrug of m6A writer METTL3/14 complex protein (pro-MPCH) can be activated in situ by tumor-associated macrophage (TAM)-targeting Fe-SA@Man, which can upregulate METTL3/14 complex protein expression and then reprogram TAMs for tumor killing by hypermethylation of m6A modification. Additionally, we find the NCs exhibit an oxidase (OXD)-like activity that further boosts the upregulation of m6A methylation and the polarization of macrophages via producing reactive oxygen species (ROS). Ultimately, the reprogrammed M1 macrophages can elicit immune responses and inhibit tumor proliferation. Our study not only sheds light on the design of single-atom catalysts for potent bioorthogonal catalysis but also provides new insights into the spatiotemporal modulation of m6A RNA methylation for the treatment of various diseases.

Ingestible Artificial Urinary Biomarker Probes for Urine Test of Gastrointestinal Cancer.

Although colorectal cancer diagnosed at an early stage shows high curability, methods simultaneously possessing point-of-care testing ability and high sensitivity are limited. Here, an orally deliverable biomarker-activatable probe (termed as HATS) for early detection of orthotopic tumors via remote urinalysis is presented. To enable its oral delivery to the colon, HATS is designed to have remarkable resistance to acidity and digestive enzymes in the stomach and small intestine and negligible intestinal absorption. Upon reaction with a cancer biomarker in the colon segment, HATS releases a small fragment of tetrazine that can transverse the intestinal barrier, enter blood circulation, and ultimately undergo renal clearance to urine. Subsequently, the urinary tetrazine fragment is detected by bioorthogonal reaction with trans-cyclooctene-caged resorufin (TCO-Reso) to afford a rapid and specific fluorescence enhancement of TCO-Reso. Such signal readout is correlated with the urinary tetrazine concentration and thus measures the level of cancer biomarkers in the colon. HATS-based optical urinalysis detects orthotopic colon tumors two weeks earlier than clinical serological tests and can be developed to a point-of-care paper test. Thereby, HATS-based urinalysis provides a non-invasive and sensitive approach to cancer screening at low-resource settings.

Gas Evolution as a Tool to Study Reaction Kinetics Under Biomimetic Conditions.

The field of bioorthogonal chemistry is rapidly growing, presenting successful applications of organic and transition metal-catalysed reactions in cells and living systems (in vivo). The development of such reactions typically proceeds through many iterative steps focused on biocompatibility and fast reaction kinetics to ensure product formation. However, obtaining kinetic data, even under simulated biological (biomimetic) conditions, remains a challenge due to substantial concentrations of salts and biomolecules hampering the use of typically employed solution-phase analytical techniques. In this study, we explored the suitability of gas evolution as a probe to study kinetics under biomimetic conditions. As proof of concept, we show that the progress of two transition metal-catalysed bioorthogonal chemical reactions can be accurately monitored, regardless of the complexity of the medium. As such, we introduce a protocol to gain more insight into the performance of a catalytic system under biomimetic conditions to further progress iterative catalyst development for in vivo applications.

Injectable and Multifunctional Hydrogels Based on Poly(N-acryloyl glycinamide) and Alginate Derivatives for Antitumor Drug Delivery.

Chemotherapy is a conventional treatment that uses drugs to kill cancer cells; however, it may induce side effects and may be incompletely effective, leading to the risk of tumor recurrence. To address this issue, we developed novel injectable thermal/near-infrared (NIR)-responsive hydrogels to control drug release. The injectable hydrogel formulation was composed of biocompatible alginates, poly(N-acryloyl glycinamide) (PNAGA) copolymers with an upper critical solution temperature, and NIR-responsive cross-linkers containing coumarin groups, which were gelated through bioorthogonal inverse electron demand Diels-Alder reactions. The hydrogels exhibited quick gelation times (120-800 s) and high drug loading efficiencies (>90%). The hydrogels demonstrated a higher percentage of drug release at 37 °C than that at 25 °C due to the enhanced swelling behavior of temperature-responsive PNAGA moieties. Upon NIR irradiation, the hydrogels released most of the entrapped doxorubicin (DOX) (97%) owing to the cleavage of NIR-sensitive coumarin ester groups. The hydrogels displayed biocompatibility with normal cells, while induced antitumor activity toward cancer cells. DOX/hydrogels treated with NIR light inhibited tumor growth in nude mice bearing tumors. In addition, the injected hydrogels emitted red fluorescence upon excitation at a green wavelength, so that the drug delivery and hydrogel degradation in vivo could be tracked in the xenograft model.

Enzyme-Mediated Bioorthogonal Cascade Catalytic Reaction for Metabolism Intervention and Enhanced Ferroptosis on Neuroblastoma.

It remains a tremendous challenge to explore effective therapeutic modalities against neuroblastoma, a lethal cancer of the sympathetic nervous system with poor prognosis and disappointing treatment outcomes. Considering the limitations of conventional treatment modalities and the intrinsic vulnerability of neuroblastoma, we herein develop a pioneering sequential catalytic therapeutic system that utilizes lactate oxidase (LOx)/horseradish peroxidase (HRP)-loaded amorphous zinc metal-organic framework, named LOx/HRP-aZIF, in combination with a 3-indole-acetic acid (IAA) prodrug. On the basis of abnormal lactate accumulation that occurs in the tumor microenvironment, the cascade reaction of LOx and HRP consumes endogenous glutathione and a reduced form of nicotinamide adenine dinucleotide to achieve the first stage of killing cancer cells via antioxidative incapacitation and electron transport chain interference. Furthermore, the generation of reactive oxygen species induced by HRP and IAA through bioorthogonal catalysis promotes ferritin degradation and lipid peroxidation, ultimately provoking self-enhanced ferroptosis with positive feedback by initiating an endogenous Fenton reaction. This work highlights the superiority of the natural enzyme-dependent cascade and bioorthogonal catalytic reaction, offering a paradigm for synergistically enzyme-based metabolism-ferroptosis anticancer therapy.

Strain-Promoted Cycloadditions in Lipid Bilayers Triggered by Liposome Fusion.

Due to the variety of roles served by the cell membrane, its composition and structure are complex, making it difficult to study. Bioorthogonal reactions, such as the strain promoted azide-alkyne cycloaddition (SPAAC), are powerful tools for exploring the function of biomolecules in their native environment but have been largely unexplored within the context of lipid bilayers. Here, we developed a new approach to study the SPAAC reaction in liposomal membranes using azide- and strained alkyne-functionalized Förster resonance energy transfer (FRET) dye pairs. This study represents the first characterization of the SPAAC reaction between diffusing molecules inside liposomal membranes. Potential applications of this work include in situ bioorthogonal labeling of membrane proteins, improved understanding of membrane dynamics and fluidity, and the generation of new probes for biosensing assays.

Strain‐Promoted Cycloadditions in Lipid Bilayers Triggered by Liposome Fusion

AbstractDue to the variety of roles served by the cell membrane, its composition and structure are complex, making it difficult to study. Bioorthogonal reactions, such as the strain promoted azide‐alkyne cycloaddition (SPAAC), are powerful tools for exploring the function of biomolecules in their native environment but have been largely unexplored within the context of lipid bilayers. Here, we developed a new approach to study the SPAAC reaction in liposomal membranes using azide‐ and strained alkyne‐functionalized Förster resonance energy transfer (FRET) dye pairs. This study represents the first characterization of the SPAAC reaction between diffusing molecules inside liposomal membranes. Potential applications of this work include in situ bioorthogonal labeling of membrane proteins, improved understanding of membrane dynamics and fluidity, and the generation of new probes for biosensing assays.

Selective activation of prodrugs in breast cancer using metabolic glycoengineering and the tetrazine ligation bioorthogonal reaction

Increasing the selectivity of chemotherapies by converting them into prodrugs that can be activated at the tumour site decreases their side effects and allows discrimination between cancerous and non-cancerous cells. Herein, the use of metabolic glycoengineering (MGE) to selectively label MCF-7 breast cancer cells with tetrazine (Tz) activators for subsequent activation of prodrugs containing the trans-cyclooctene (TCO) moiety by a bioorthogonal reaction is demonstrated. Three novel Tz-modified monosaccharides, Ac4ManNTz 7, Ac4GalNTz 8, and Ac4SiaTz 16, were used for expression of the Tz activator within sialic-acid rich breast cancer cells’ surface glycans through metabolic glycoengineering. Tz expression on breast cancer cells (MCF-7) was evaluated versus the non-cancerous L929 fibroblasts showing a concentration-dependant effect and excellent selectivity with ≥35-fold Tz expression on the MCF-7 cells versus the non-cancerous L929 fibroblasts. Next, a novel TCO-N-mustard prodrug along with a TCO-doxorubicin prodrug were analyzed in vitro on the Tz-bioengineered cells to probe our hypothesis that these could be activated via a bioorthogonal reaction. Selective prodrug activation and restoration of cytotoxicity were demonstrated for the MCF-7 breast cancer cells versus the non-cancerous L929 cells. Restoration of the parent drug’s cytotoxicity was shown to be dependent on the level of Tz expression where the Ac4ManNTz 7 and Ac4GalNTz 8 derivatives (20 µM) lead to the highest Tz expression and full restoration of the parent drug’s cytotoxicity. This work suggests the feasibility of combining MGE and tetrazine ligation for selective prodrug activation in breast cancer.

Minimalist Tetrazine N-Acetyl Muramic Acid Probes for Rapid and Efficient Labeling of Commensal and Pathogenic Peptidoglycans in Living Bacterial Culture and During Macrophage Invasion.

N-Acetyl muramic acid (NAM) probes containing alkyne or azide groups are commonly used to investigate aspects of cell wall synthesis because of their small size and ability to incorporate into bacterial peptidoglycan (PG). However, copper-catalyzed alkyne-azide cycloaddition (CuAAC) reactions are not compatible with live cells, and strain-promoted alkyne-azide cycloaddition (SPAAC) reaction rates are modest and, therefore, not as desirable for tracking the temporal alterations of bacterial cell growth, remodeling, and division. Alternatively, the tetrazine-trans-cyclooctene ligation (Tz-TCO), which is the fastest known bioorthogonal reaction and not cytotoxic, allows for rapid live-cell labeling of PG at biologically relevant time scales and concentrations. Previous work to increase reaction kinetics on the PG surface by using tetrazine probes was limited because of low incorporation of the probe. Described here are new approaches to construct a minimalist tetrazine (Tz)-NAM probe utilizing recent advancements in asymmetric tetrazine synthesis. This minimalist Tz-NAM probe was successfully incorporated into pathogenic and commensal bacterial PG where fixed and rapid live-cell, no-wash labeling was successful in both free bacterial cultures and in coculture with human macrophages. Overall, this probe allows for expeditious labeling of bacterial PG, thereby making it an exceptional tool for monitoring PG biosynthesis for the development of new antibiotic screens. The versatility and selectivity of this probe will allow for real-time interrogation of the interactions of bacterial pathogens in a human host and will serve a broader utility for studying glycans in multiple complex biological systems.

Double cross-linked graphene oxide hydrogel for promoting healing of diabetic ulcers.

This study explores the synthesis and characterization of a novel double cross-linked hydrogel composed of polyvinyl alcohol (PVA), sodium alginate (SA), graphene oxide (GO), and glutathione (GSH), henceforth referred to as PVA/SA/GO/GSH. This innovative hydrogel system incorporates two distinct types of cross-linking networks and is meticulously engineered to exhibit sensitivity to high glucose and/or reactive oxygen species (ROS) environments. A sequential approach was adopted in the hydrogel formation. The initial phase involved the absorption of GSH onto GO, which was subsequently functionalized with boric acid and polyethylene glycol derivatives via a bio-orthogonal click reaction. This stage constituted the formation of the first chemically cross-linked network. Subsequently, freeze-thaw cycles were utilized to induce a secondary cross-linking process involving PVA and SA, thereby forming the second physically cross-linked network. The resultant PVA/SA/GO/GSH hydrogel retained the advantageous hydrogel properties such as superior water retention capacity and elasticity, and additionally exhibited the ability to responsively release GSH under changes in glucose concentration and/or ROS levels. This feature finds particular relevance in the therapeutic management of diabetic ulcers. Preliminary in vitro evaluation affirmed the hydrogel's biocompatibility and its potential to promote cell migration, inhibit apoptosis, and exhibit antibacterial properties. Further in vivo studies demonstrated that the PVA/SA/GO/GSH hydrogel could facilitate the healing of diabetic ulcer sites by mitigating oxidative stress and regulating glucose levels. Thus, the developed PVA/SA/GO/GSH hydrogel emerges as a promising candidate for diabetic ulcer treatment, owing to its specific bio-responsive traits and therapeutic efficacy.

Covalent coupling of functionalized outer membrane vesicles (OMVs) to gold nanoparticles

Outer membrane vesicle-functionalized nanoparticles (OMV-NPs) have attracted significant interest, especially regarding drug delivery applications and vaccines. Here, we report on novel OMV-NPs by applying bioorthogonal click reaction for encapsulating gold nanoparticles (NPs) within outer membrane vesicles (OMVs) by covalent coupling. For this purpose, outer membrane protein A (OmpA), abundant in large numbers (due to 100,000 copies/cell [1]) in OMVs, was modified via the incorporation of the unnatural amino acid p–azidophenylalanine. The azide group was covalently coupled to alkyne-functionalized NPs after incorporation into OmpA. A simplified procedure using low-speed centrifugation (1,000 x g) was developed for preparing OMV-NPs. The OMV-NPs were characterized by zeta potential, Laurdan-based lipid membrane dynamics studies, and the enzymatic activity of functionalized OMVs with surface-displayed nicotinamide adenine dinucleotide oxidase (Nox). In addition, OMVs from attenuated bacteria (ClearColiTM BL21(DE3), E. coli F470) with surface-displayed Nox or antibody fragments were prepared and successfully coupled to AuNPs. Finally, OMV-NPs displaying single-chain variable fragments from a monoclonal antibody directed against epidermal growth factor receptor were applied to demonstrate the feasibility of OMV-NPs for tumor cell targeting.

A Therapeutic Pretargeting Strategy for Triple‐Negative Breast Cancer Based on a Bioorthogonal Reaction and a Self‐Assembled Peptide

AbstractTriple‐negative breast cancer (TNBC), a disease with a poor prognosis and high mortality, is difficult to targeted therapy, due to the metastatic nature of TNBC cells and their lack of estrogen, progesterone, and Her‐2/Neu receptor targets. Here, a novel pretargeting strategy involving self‐assembled peptides and a bioorthogonal reaction are described. This process generates nanofibers on TNBC cell surface that prevent them migration and invasion and deliver untargeted anticancer drugs (e.g., doxorubicin) that synergistically eliminates TNBC cells. The self‐assembled peptide contains four modules: i) an aromatic group‐rich tetraphenylethylene (TPE) unit for promoting self‐assembly and nanofiber formation, ii) a GFFY peptide motif that supports self‐assembly of nanofibers into peptide scaffolds, iii) a targeting RGD motif that binding with the abundant integrin molecules present on TNBC cell surface, and iv) an azide group acting as the bioorthogonal reaction site that reacts with drugs or probes containing the dibenzocyclooctyne (DBCO) group. Results of in vitro and in vivo experiments indicate that the self‐assembled peptide inhibits tumor invasion and metastasis, while also pretargeting and killing TNBC cells with superior effectiveness and lower toxicity to that of current chemotherapies. In conclusion, this novel bioorthogonal pretargeting strategy holds promise as an effective anticancer therapeutic approach.