A Raman Imaging Approach Using CD47 Antibody-Labeled SERS Nanoparticles for Identifying Breast Cancer and Its Potential to Guide Surgical Resection

Abstract

Raman spectroscopic imaging has shown great promise for improved cancer detection and localization with the use of tumor targeting surface enhanced Raman scattering (SERS) nanoparticles. With the ultrasensitive detection and multiplexing capabilities that SERS imaging has to offer, scientists have been investigating several clinical applications that could benefit from this unique imaging strategy. Recently, there has been a push to develop new image-guidance tools for surgical resection to help surgeons sensitively and specifically identify tumor margins in real time. We hypothesized that SERS nanoparticles (NPs) topically applied to breast cancer resection margins have the potential to provide real-time feedback on the presence of residual cancer in the resection margins during lumpectomy. Here, we explore the ability of SERS nanoparticles conjugated with a cluster of differentiation-47 (CD47) antibody to target breast cancer. CD47 is a cell surface receptor that has recently been shown to be overexpressed on several solid tumor types. The binding potential of our CD47-labeled SERS nanoparticles was assessed using fluorescence assisted cell sorting (FACS) on seven different human breast cancer cell lines, some of which were triple negative (negative expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2)). Xenograft mouse models were also used to assess the ability of our Raman imaging system to identify tumor from normal tissue. A ratiometric imaging strategy was used to quantify specific vs. nonspecific probe binding, resulting in improved tumor-to-background ratios. FACS analysis showed that CD47-labeled SERS nanoparticles bound to seven different breast cancer cell lines at levels 12-fold to 70-fold higher than isotype control-labeled nanoparticles (p < 0.01), suggesting that our CD47-targeted nanoparticles actively bind to CD47 on breast cancer cells. In a mouse xenograft model of human breast cancer, topical application of CD47-targeted nanoparticles to excised normal and cancer tissue revealed increased binding of CD47-targeted nanoparticles on tumor relative to normal adjacent tissue. The findings of this study support further investigation and suggest that SERS nanoparticles topically applied to breast cancer could guide more complete surgical resection during lumpectomy.

Role of CD47 in Hematological Malignancies

“…Mitomycin A-loaded nanoparticles showed downregulation of CD47 expression in xenografted mice [90]. Davis et al combined anti-CD47 antibodies with nanoparticles to target ovarian cancer cells [91]. No update information about using such vehicles in targeting CD47 in hematological malignancies.…”

Characterisation of estrogen receptor alpha (ERα) expression in breast cancer cells and effect of drug treatment using targeted nanoparticles and SERS

“…SERS nanotags have been successfully synthesised for various bioanalytical measurements of cancer cells 27,28 including breast cancer. [29][30][31] The design of these SERS nanotags usually involves attaching Raman reporters to the surface of gold (Au) or silver (Ag) nanoparticles (NPs) and functionalising with a specific targeting biomolecule, such as monoclonal antibodies, drugs or DNA sequences. 32 Poly-ethylene glycol (PEG) can also be attached to the nanoparticle surface to avoid dissociation of the functionalised biomolecules, decrease the toxic effects, 33 reduce nonspecific cellular internalisation, 34 facilitate longer circulation time in biological fluids 35 and reduce aggregation of nanotags in biological solutions.…”

Label-Free Visualization and Tracking of Gold Nanoparticles in Vasculature Using Multiphoton Luminescence

“…Nanoparticles have great potential for several biomedical applications and are currently being used as drug delivery vehicles, treatment response monitors, and in early-stage disease diagnostics [ 1 , 2 , 3 , 4 ]. As imaging contrast agents, nanoparticles have distinct advantages over their small molecule counterparts and are exploited in a wide variety of imaging modalities [ 5 , 6 ]. In particular, gold nanoparticles have been used as multimodal imaging agents with applications in computed tomography (CT), photoacoustic and Raman imaging [ 6 , 7 , 8 , 9 ].…”

“…As imaging contrast agents, nanoparticles have distinct advantages over their small molecule counterparts and are exploited in a wide variety of imaging modalities [ 5 , 6 ]. In particular, gold nanoparticles have been used as multimodal imaging agents with applications in computed tomography (CT), photoacoustic and Raman imaging [ 6 , 7 , 8 , 9 ]. Gold nanoparticles are also increasingly utilized as “theranostic” agents, combining therapeutic uses such as thermal ablation with other diagnostic imaging capabilities [ 10 , 11 ].…”