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Updated: Aug 28, 2025
Synthesis of Near-Infrared Emitting Gold Nanoclusters for Biological Applications
Published on: March 22, 2020
Multifunctional Gold Nanoclusters for Effective Targeting, Near-Infrared Fluorescence Imaging, Diagnosis, and
Zeyang Pang1,2, Weixiao Yan1, Jie Yang1
1Guangdong Provincial Key Laboratory of Advanced Biomaterials and Shenzhen Key Laboratory of Smart Healthcare Engineering, Department of Biomedical Engineering, Southern University of Science and Technology, No 1088, Xueyuan Rd, Nanshan District, Shenzhen, Guangdong 518055, P. R. China.
Abstract:
Developing effective lymph-node (LN) targeting and imaging probes is crucial for the early detection and diagnosis of tumor metastasis to improve patient survival. Most current clinical LN imaging probes are based on small organic dyes (e.g., indocyanine green) or radioactive 99mTc-complexes, which often suffer from limitations, such as rapid photobleaching, poor signal contrast, and potential biosafety issues. Moreover, these probes cannot easily incorporate therapeutic functions to realize beneficial theranostics without affecting their LN-targeting ability. Herein, we have developed dual-ligand-/multiligand-capped gold nanoclusters (GNCs) for specific targeting, near-infrared (NIR) fluorescence imaging, diagnosis, and treatment of LN cancer metastasis in in vivo mouse models. By optimizing the surface ligand coating, we have prepared Au25(SR1)n(SR2)18-n (where SR1 and SR2 are different functional thiol ligands)-type GNCs, which display highly effective LN targeting, excellent stability and biocompatibility, and optimal body-retention time. Moreover, they can provide continuous NIR fluorescence imaging of LNs for >3 h from a single dose, making them well-suited for fluorescence-guided surgery. Importantly, we have further incorporated methotrexate, a chemotherapeutic drug, into the GNCs without affecting their LN-targeting ability. Consequently, they can significantly improve the efficiency of methotrexate delivery to target LNs, achieving excellent therapeutic efficacy with up to 4-fold lower hepatotoxicity. Thus, the GNCs are highly effective and safe theranostic nanomedicines against cancer lymphatic metastasis.
Insights
Researchers developed novel gold nanoclusters (GNCs) for enhanced lymph node (LN) targeting and imaging. These GNCs offer improved diagnosis and treatment of cancer metastasis with reduced toxicity.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Oncology
Background:
- Effective lymph node (LN) targeting and imaging are vital for diagnosing tumor metastasis and improving patient survival.
- Current LN imaging probes have limitations including photobleaching, poor contrast, and biosafety concerns, and often lack therapeutic capabilities.
- Existing probes struggle to integrate therapeutic functions without compromising LN-targeting ability.
Purpose of the Study:
- To develop dual-ligand/multiligand-capped gold nanoclusters (GNCs) for specific LN targeting, near-infrared (NIR) fluorescence imaging, diagnosis, and treatment of LN cancer metastasis.
- To optimize GNC surface ligands for enhanced LN targeting, stability, biocompatibility, and body retention.
- To incorporate a chemotherapeutic drug into GNCs for theranostic applications without affecting LN-targeting efficacy.
Main Methods:
- Synthesis of Au25(SR1)n(SR2)18-n type GNCs with optimized dual/multiligand surface coatings.
- Evaluation of LN targeting efficiency, NIR fluorescence imaging capabilities, stability, and biocompatibility in vivo.
- Assessment of theranostic efficacy by incorporating methotrexate and evaluating therapeutic outcomes and hepatotoxicity.
Main Results:
- Optimized GNCs demonstrated highly effective LN targeting, excellent stability, biocompatibility, and optimal body retention.
- Continuous NIR fluorescence imaging of LNs was achieved for over 3 hours post-administration.
- Methotrexate-loaded GNCs showed improved drug delivery to target LNs, enhanced therapeutic efficacy, and significantly reduced hepatotoxicity (4-fold lower).
Conclusions:
- Dual-ligand/multiligand-capped GNCs are effective and safe theranostic nanomedicines for targeting and treating cancer lymphatic metastasis.
- These GNCs offer a promising platform for fluorescence-guided surgery and improved cancer therapy.
- The developed GNCs overcome limitations of current probes, enabling combined diagnostic and therapeutic applications.
