1
|
Gao F, Liu F, Wang J, Bi J, Zhai L, Li D. Molecular probes targeting HER2 PET/CT and their application in advanced breast cancer. J Cancer Res Clin Oncol 2024; 150:118. [PMID: 38466436 PMCID: PMC10927773 DOI: 10.1007/s00432-023-05519-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/12/2023] [Indexed: 03/13/2024]
Abstract
PURPOSE Human epidermal growth factor receptor 2 (HER2)-positive breast cancer cases are among the most aggressive breast tumor subtypes. Accurately assessing HER2 expression status is vital to determining whether patients will benefit from targeted anti-HER2 treatment. HER2-targeted positron emission tomography (PET/CT) is noninvasive, enabling the real-time evaluation of breast cancer patient HER2 status with accuracy. METHODS We summarize the research progress of PET/CT targeting HER2 in breast cancer, focusing on PET/CT molecular probes targeting HER2 and their clinical application in the management of advanced breast cancer. RESULTS At present, a variety of different HER2 targeted molecular probes for PET/CT imaging have been developed, including nucleolin-labeled antibodies, antibody fragments, nanobodies, and peptides of various affinities, among others. HER2-targeted PET/CT can relatively accurately evaluate HER2 expression status in advanced breast cancer patients. It has good performance in the early detection of small HER2-positive lesions, evaluation of HER2 status in lesions that cannot be readily biopsied, evaluation of the heterogeneity of multiple metastases, identification of lesions with altered HER2 status, and evaluation of the efficacy of anti-HER2 drugs. CONCLUSION HER2-targeted PET/CT offers a promising noninvasive approach for real-time assessment of HER2 status,which can be guide targeted treatment for HER2-positive breast cancer patients. Future prospective clinical studies will be invaluable for fully evaluating the importance of HER2-targeted molecular imaging in the management of breast cancer.
Collapse
Affiliation(s)
- Fang Gao
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China
| | - Fengxu Liu
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China
| | - Jun Wang
- Department of Anesthesia, Armed Police Corps Hospital in Shanxi Province, Xiaodian District, Taiyuan, Shanxi, People's Republic of China
| | - Junfang Bi
- Department of Combined Traditional Chinese Medicine and West Medicine, Traditional Chinese Medicine Hospital of Shijiazhuang City, 233 Zhongshan West Road, Qiaoxi District, Shijiazhuang, Hebei, China
| | - Luoping Zhai
- Department of Nuclear Medicine, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China.
| | - Dong Li
- General Surgery Department, Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China.
- Shanxi Province Cancer Hospital/ Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Cancer Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China.
| |
Collapse
|
2
|
Byun KT, Kim B, Cho J, Lee I, Lee MG, Park D, Kang TB, Won HS, Kim CG. Development of an Anti-HER2 Single-Chain Variable Antibody Fragment Construct for High-Yield Soluble Expression in Escherichia coli and One-Step Chromatographic Purification. Biomolecules 2023; 13:1508. [PMID: 37892190 PMCID: PMC10605039 DOI: 10.3390/biom13101508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Although single-chain variable fragment (scFv) is recognized as a highly versatile scaffold of recombinant antibody fragment molecules, its overexpression in Escherichia coli often leads to the formation of inclusion bodies. To address this issue, we devised and tested four different constructs, named v21, v22, v23 and v24, for producing anti-human epidermal growth factor receptor 2 (HER2) scFv. Among them, the v24 construct obtained from N-terminal fusion of maltose-binding protein (MBP) and subsequent tobacco etch virus protease (TEV) was identified as the most efficient construct for the production of anti-HER2 scFv. Aided by an MBP tag, high-yield soluble expression was ensured and soluble scFv was liberated in cells via autonomous proteolytic cleavage by endogenously expressed TEV. The isolated scFv containing a C-terminal hexahistidine tag was purified through a one-step purification via nickel-affinity chromatography. The purified scFv exhibited a strong (nanomolar Kd) affinity to HER2 both in vitro and in cells. Structural and functional stabilities of the scFv during storage for more than one month were also assured. Given the great utility of anti-HER2 scFv as a basic platform for developing therapeutic and diagnostic agents for cancers, the v24 construct and methods presented in this study are expected to provide a better manufacturing system for producing anti-HER2 scFv with various industrial applications.
Collapse
Affiliation(s)
- Kyu Tae Byun
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
| | - Boram Kim
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
| | - Junmin Cho
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
| | - Inbeom Lee
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
| | - Myung Gu Lee
- Konkukbio Inc., Konkuk University, Chungju 27478, Republic of Korea
| | - Dongsun Park
- Department of Biology Education, Korea National University of Education, Cheongju 28173, Republic of Korea
| | - Tae-Bong Kang
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
- BK21 Project Team, Department of Applied Life Science, Graduate School, Konkuk University, Chungju 27478, Republic of Korea
| | - Hyung-Sik Won
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
- BK21 Project Team, Department of Applied Life Science, Graduate School, Konkuk University, Chungju 27478, Republic of Korea
| | - Chan Gil Kim
- Department of Biotechnology, Research Institute (RIBHS), College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; (K.T.B.); (B.K.)
| |
Collapse
|
3
|
Modern Developments in Bifunctional Chelator Design for Gallium Radiopharmaceuticals. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010203. [PMID: 36615397 PMCID: PMC9822085 DOI: 10.3390/molecules28010203] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022]
Abstract
The positron-emitting radionuclide gallium-68 has become increasingly utilised in both preclinical and clinical settings with positron emission tomography (PET). The synthesis of radiochemically pure gallium-68 radiopharmaceuticals relies on careful consideration of the coordination chemistry. The short half-life of 68 min necessitates rapid quantitative radiolabelling (≤10 min). Desirable radiolabelling conditions include near-neutral pH, ambient temperatures, and low chelator concentrations to achieve the desired apparent molar activity. This review presents a broad overview of the requirements of an efficient bifunctional chelator in relation to the aqueous coordination chemistry of gallium. Developments in bifunctional chelator design and application are then presented and grouped according to eight categories of bifunctional chelator: the macrocyclic chelators DOTA and TACN; the acyclic HBED, pyridinecarboxylates, siderophores, tris(hydroxypyridinones), and DTPA; and the mesocyclic diazepines.
Collapse
|
4
|
Suzuki H, Muramatsu S, Ichinohe K, Uchimura M, Araki M, Uehara T, Arano Y. Stability Estimation of Gallium Complexes of DOTA Derivatives for Radiotheranostic Applications. ACS OMEGA 2022; 7:43321-43328. [PMID: 36467905 PMCID: PMC9713862 DOI: 10.1021/acsomega.2c06814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 11/07/2022] [Indexed: 06/17/2023]
Abstract
1,4,7,10-Tetraazacyclododecane-1,4,7-triacetic acid (DO3A) has been used to prepare 68Ga-labeled probes for the diagnostic counterpart of radiotheranostic applications. While DO3A provides stable complexes with therapeutic radionuclides such as 90Y, 177Lu, and 225Ac, further improvement of the in vivo stability of the Ga-DO3A complex is required. Considering the high stability of an intact Ga-DOTA complex, the stability of Ga complexes of DOTA and DO3A derivatives, including benzyl-DOTA (Bn-DOTA), was evaluated to gain fundamental knowledge for developing the next-generation radiotheranostic probes using 68Ga as a diagnostic counterpart. Following the complexation reaction to prepare 67Ga-labeled DOTA and DO3A derivatives, the stability of the resulting 67Ga-labeled compounds was evaluated in murine plasma and apo-transferrin challenge. [67Ga]Ga-Bn-DOTA produced two isomers, and one of the isomers exhibited the highest stability among the tested complexes. The X-ray crystallography showed that the less stable isomer of Ga-Bn-DOTA suggested an N3O3 coordination geometry, while Ga-DOTA and Ga-Bn-DO3A show N4O2 coordination. To further evaluate the stability, a synthetic somatostatin analogue, [Tyr3]octreotide (TOC), was used as a model peptide, and p-COOH-Bn-DOTA and DO3A were conjugated with TOC to prepare DOTA-Bn-TOC and DOTATOC. [67Ga]Ga-DOTA-Bn-TOC also yielded two isomers with varying stability, and one isomer exhibited significantly higher stability than [67Ga]Ga-DOTATOC both in vitro and in vivo. These findings indicate that para-substituted Bn-DOTA would constitute a suitable chelating agent for developing next-generation radiotheranostic probes, although high-performance liquid chromatography purification is needed. Thus, further chemical modification on the Bn-DOTA molecule is also needed to avoid the formation of a Ga complex with the N3O3 configuration.
Collapse
|
5
|
Lugat A, Bailly C, Chérel M, Rousseau C, Kraeber-Bodéré F, Bodet-Milin C, Bourgeois M. Immuno-PET: Design options and clinical proof-of-concept. Front Med (Lausanne) 2022; 9:1026083. [PMID: 36314010 PMCID: PMC9613928 DOI: 10.3389/fmed.2022.1026083] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 09/29/2022] [Indexed: 11/23/2022] Open
Abstract
Radioimmunoconjugates have been used for over 30 years in nuclear medicine applications. In the last few years, advances in cancer biology knowledge have led to the identification of new molecular targets specific to certain patient subgroups. The use of these targets in targeted therapies approaches has allowed the developments of specifically tailored therapeutics for patients. As consequence of the PET-imaging progresses, nuclear medicine has developed powerful imaging tools, based on monoclonal antibodies, to in vivo characterization of these tumor biomarkers. This imaging modality known as immuno-positron emission tomography (immuno-PET) is currently in fastest-growing and its medical value lies in its ability to give a non-invasive method to assess the in vivo target expression and distribution and provide key-information on the tumor targeting. Currently, immuno-PET presents promising probes for different nuclear medicine topics as staging/stratification tool, theranostic approaches or predictive/prognostic biomarkers. To develop a radiopharmaceutical drug that can be used in immuno-PET approach, it is necessary to find the best compromise between the isotope choice and the immunologic structure (full monoclonal antibody or derivatives). Through some clinical applications, this paper review aims to discuss the most important aspects of the isotope choice and the usable proteic structure that can be used to meet the clinical needs.
Collapse
Affiliation(s)
- Alexandre Lugat
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France
| | - Clément Bailly
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Nuclear Medicine Department, University Hospital, Nantes, France
| | - Michel Chérel
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Department of Nuclear Medicine, Institut de Cancérologie de l'Ouest (ICO) – Site Gauducheau, Saint-Herblain, France
| | - Caroline Rousseau
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Department of Nuclear Medicine, Institut de Cancérologie de l'Ouest (ICO) – Site Gauducheau, Saint-Herblain, France
| | - Françoise Kraeber-Bodéré
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Nuclear Medicine Department, University Hospital, Nantes, France
| | - Caroline Bodet-Milin
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Nuclear Medicine Department, University Hospital, Nantes, France
| | - Mickaël Bourgeois
- Nantes-Angers Cancer Research Center CRCI2NA, University of Nantes, INSERM UMR1307, CNRS-ERL6075, Nantes, France,Nuclear Medicine Department, University Hospital, Nantes, France,ARRONAX Cyclotron, Saint-Herblain, France,*Correspondence: Mickaël Bourgeois
| |
Collapse
|
6
|
Extracellular production of an anti-HER2 single-chain variable antibody fragment in Escherichia coli. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
7
|
Chomet M, van Dongen GAMS, Vugts DJ. State of the Art in Radiolabeling of Antibodies with Common and Uncommon Radiometals for Preclinical and Clinical Immuno-PET. Bioconjug Chem 2021; 32:1315-1330. [PMID: 33974403 PMCID: PMC8299458 DOI: 10.1021/acs.bioconjchem.1c00136] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Inert
and stable radiolabeling of monoclonal antibodies (mAb),
antibody fragments, or antibody mimetics with radiometals is a prerequisite
for immuno-PET. While radiolabeling is preferably fast, mild, efficient,
and reproducible, especially when applied for human use in a current
Good Manufacturing Practice compliant way, it is crucial that the
obtained radioimmunoconjugate is stable and shows preserved immunoreactivity
and in vivo behavior. Radiometals and chelators have
extensively been evaluated to come to the most ideal radiometal–chelator
pair for each type of antibody derivative. Although PET imaging of
antibodies is a relatively recent tool, applications with 89Zr, 64Cu, and 68Ga have greatly increased in
recent years, especially in the clinical setting, while other less
common radionuclides such as 52Mn, 86Y, 66Ga, and 44Sc, but also 18F as in [18F]AlF are emerging promising candidates for the radiolabeling
of antibodies. This review presents a state of the art overview of
the practical aspects of radiolabeling of antibodies, ranging from
fast kinetic affibodies and nanobodies to slow kinetic intact mAbs.
Herein, we focus on the most common approach which consists of first
modification of the antibody with a chelator, and after eventual storage
of the premodified molecule, radiolabeling as a second step. Other
approaches are possible but have been excluded from this review. The
review includes recent and representative examples from the literature
highlighting which radiometal–chelator–antibody combinations
are the most successful for in vivo application.
Collapse
Affiliation(s)
- Marion Chomet
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Guus A M S van Dongen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Danielle J Vugts
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| |
Collapse
|
8
|
Rinne SS, Orlova A, Tolmachev V. PET and SPECT Imaging of the EGFR Family (RTK Class I) in Oncology. Int J Mol Sci 2021; 22:ijms22073663. [PMID: 33915894 PMCID: PMC8036874 DOI: 10.3390/ijms22073663] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
The human epidermal growth factor receptor family (EGFR-family, other designations: HER family, RTK Class I) is strongly linked to oncogenic transformation. Its members are frequently overexpressed in cancer and have become attractive targets for cancer therapy. To ensure effective patient care, potential responders to HER-targeted therapy need to be identified. Radionuclide molecular imaging can be a key asset for the detection of overexpression of EGFR-family members. It meets the need for repeatable whole-body assessment of the molecular disease profile, solving problems of heterogeneity and expression alterations over time. Tracer development is a multifactorial process. The optimal tracer design depends on the application and the particular challenges of the molecular target (target expression in tumors, endogenous expression in healthy tissue, accessibility). We have herein summarized the recent preclinical and clinical data on agents for Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) imaging of EGFR-family receptors in oncology. Antibody-based tracers are still extensively investigated. However, their dominance starts to be challenged by a number of tracers based on different classes of targeting proteins. Among these, engineered scaffold proteins (ESP) and single domain antibodies (sdAb) show highly encouraging results in clinical studies marking a noticeable trend towards the use of smaller sized agents for HER imaging.
Collapse
Affiliation(s)
- Sara S. Rinne
- Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden; (S.S.R.); (A.O.)
| | - Anna Orlova
- Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden; (S.S.R.); (A.O.)
- Science for Life Laboratory, Uppsala University, 752 37 Uppsala, Sweden
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia
| | - Vladimir Tolmachev
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia
- Department of Immunology, Genetics and Pathology, Uppsala University, 752 37 Uppsala, Sweden
- Correspondence: ; Tel.: +46-704-250-782
| |
Collapse
|
9
|
Ding N, Sano K, Kanazaki K, Shimizu Y, Watanabe H, Namita T, Shiina T, Ono M, Saji H. Sensitive Photoacoustic/Magnetic Resonance Dual Imaging Probe for Detection of Malignant Tumors. J Pharm Sci 2020; 109:3153-3159. [PMID: 32679213 DOI: 10.1016/j.xphs.2020.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/23/2020] [Accepted: 07/08/2020] [Indexed: 01/18/2023]
Abstract
In order to completely remove tumors in surgeries, probes are needed both preoperatively and intraoperatively. For tumor diagnosis, magnetic resonance imaging (MRI) has been widely used as a precise preoperative method, and photoacoustic imaging (PAI) is a recently emerged intraoperative (or preoperative) method, which detects ultrasonic waves thermoelastically induced by optical absorbers irradiated by laser. Iron oxide nanoparticles (IONPs) can be used as both MR and PA imaging probes. In order to improve the sensitivity of IONPs as MR/PA imaging probes, we newly prepared liposomes encapsulated with a number of IONPs (Lipo-IONPs). Interestingly, Lipo-IONPs showed 2.6 and 3.8-times higher PA and MR signals, respectively, compared to dispersed IONPs at the same concentration. Furthermore, trastuzumab (Tra) (anti-human epidermal growth factor receptor 2 (EGFR2; HER2) monoclonal antibody) was introduced onto the surface of liposomes for detection of HER2 related to tumor malignancy. In an cellular uptake study, Tra-Lipo-IONPs were taken up by HER2-positive tumor cells and HER2-specific MR/PA dual imaging was achieved. Finally, a biodistribution study using radiolabeled Tra-Lipo-IONPs showed HER2-specific tumor accumulation. In conclusion, we demonstrated the usefulness of Lipo-IONPs as platforms for sensitive MR/PA dual imaging and the possibility of HER2-specific tumor MR/PA imaging using Tra-Lipo-IONPs.
Collapse
Affiliation(s)
- Ning Ding
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kohei Sano
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan; Laboratory of Biophysical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyama Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Kengo Kanazaki
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan; Medical Imaging Project, Corporate R&D Headquarters, Canon Inc., 3-30-2 Shimomaruko, Ohta-ku, Tokyo 146-8501, Japan
| | - Yoichi Shimizu
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Watanabe
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takeshi Namita
- Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Tsuyoshi Shiina
- Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Masahiro Ono
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hideo Saji
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| |
Collapse
|
10
|
Kulkarni S, Pandey A, Mutalik S. Liquid metal based theranostic nanoplatforms: Application in cancer therapy, imaging and biosensing. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 26:102175. [DOI: 10.1016/j.nano.2020.102175] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/03/2020] [Accepted: 02/25/2020] [Indexed: 12/29/2022]
|
11
|
Zhao X, Ning Q, Mo Z, Tang S. A promising cancer diagnosis and treatment strategy: targeted cancer therapy and imaging based on antibody fragment. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2020; 47:3621-3630. [PMID: 31468992 DOI: 10.1080/21691401.2019.1657875] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With the arrival of the precision medicine and personalized treatment era, targeted therapy that improves efficacy and reduces side effects has become the mainstream approach of cancer treatment. Antibody fragments that further enhance penetration and retain the most critical antigen-specific binding functions are considered the focus of research targeting cancer imaging and therapy. Thanks to the superior penetration and rapid blood clearance of antibody fragments, antibody fragment-based imaging agents enable efficient and sensitive imaging of tumour sites. In tumour-targeted therapy, antibody fragments can directly inhibit tumour proliferation and growth, serve as an ideal carrier for delivery of anti-tumour drugs, or manipulate the immune system to eliminate tumour cells. In this review, the excellent physicochemical properties and the basic structure of antibody fragments are expressly depicted depicted, the progress of antibody fragments in cancer therapy and imaging are thoroughly summarized, and the future development of antibody fragments is predicted.
Collapse
Affiliation(s)
- Xuhong Zhao
- Learning Key Laboratory for Pharmacoproteomics of Hunan Province, Institute of Pharmacy and Pharmacology, University of South China , Hengyang , China.,Hunan Province Key Laboratory for Antibody-Based Drug and Intelligent Delivery System, Hunan University of Medicine , Huaihua , China
| | - Qian Ning
- Hunan Province Key Laboratory for Antibody-Based Drug and Intelligent Delivery System, Hunan University of Medicine , Huaihua , China
| | - Zhongcheng Mo
- Department of Histology and Embryology, Clinical Anatomy and Reproductive Medicine Application Institute, Hengyang Medical School, University of South China , Hengyang , China
| | - Shengsong Tang
- Learning Key Laboratory for Pharmacoproteomics of Hunan Province, Institute of Pharmacy and Pharmacology, University of South China , Hengyang , China.,Hunan Province Key Laboratory for Antibody-Based Drug and Intelligent Delivery System, Hunan University of Medicine , Huaihua , China
| |
Collapse
|
12
|
Ui T, Ueda M, Higaki Y, Kamino S, Sano K, Kimura H, Saji H, Enomoto S. Development and characterization of a 68Ga-labeled A20FMDV2 peptide probe for the PET imaging of αvβ6 integrin-positive pancreatic ductal adenocarcinoma. Bioorg Med Chem 2020; 28:115189. [PMID: 31740201 DOI: 10.1016/j.bmc.2019.115189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/25/2019] [Accepted: 10/27/2019] [Indexed: 01/29/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is known to be one of the most lethal cancers. Since the majority of patients are diagnosed at an advanced stage, development of a detection method for PDAC at an earlier stage of disease progression is strongly desirable. Integrin αVβ6 is a promising target for early PDAC detection because its expression increases during precancerous changes. The present study aimed to develop an imaging probe for positron emission tomography (PET) which targets αVβ6 integrin-positive PDAC. We selected A20FMDV2 peptide, which binds specifically to αvβ6 integrin, as a probe scaffold, and 68Ga as a radioisotope. A20FMDV2 peptide has not been previously labeled with 68Ga. A cysteine residue was introduced to the N-terminus of the probe at a site-specific conjugation of maleimide-NOTA (mal-NOTA) chelate. Different numbers of glycine residues were also introduced between cysteine and the A20FMDV2 sequence as a spacer in order to reduce the steric hindrance of the mal-NOTA on the binding probe to αVβ6 integrin. In vitro, the competitive binding assay revealed that probes containing a 6-glycine linker ([natGa]CG6 and [natGa]Ac-CG6) showed high affinity to αVβ6 integrin. Both probes could be labeled by 67/68Ga with high radiochemical yield (>50%) and purity (>98%). On biodistribution analysis, [67Ga]Ac-CG6 showed higher tumor accumulation, faster blood clearance, and lower accumulation in the surrounding organs of pancreas than did [67Ga]CG6. The αVβ6 integrin-positive xenografts were clearly visualized by PET imaging with [68Ga]Ac-CG6. The intratumoral distribution of [68Ga]Ac-CG6 coincided with the αVβ6 integrin-positive regions detected by immunohistochemistry. Thus, [68Ga]Ac-CG6 is a useful peptide probe for the imaging of αVβ6 integrin in PDAC.
Collapse
Affiliation(s)
- Takashi Ui
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Masashi Ueda
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
| | - Yusuke Higaki
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Shinichiro Kamino
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Kohei Sano
- Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hiroyuki Kimura
- Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hideo Saji
- Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuichi Enomoto
- RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| |
Collapse
|
13
|
Fu R, Carroll L, Yahioglu G, Aboagye EO, Miller PW. Antibody Fragment and Affibody ImmunoPET Imaging Agents: Radiolabelling Strategies and Applications. ChemMedChem 2018; 13:2466-2478. [PMID: 30246488 PMCID: PMC6587488 DOI: 10.1002/cmdc.201800624] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Indexed: 12/12/2022]
Abstract
Antibodies have long been recognised as potent vectors for carrying diagnostic medical radionuclides, contrast agents and optical probes to diseased tissue for imaging. The area of ImmunoPET combines the use of positron emission tomography (PET) imaging with antibodies to improve the diagnosis, staging and monitoring of diseases. Recent developments in antibody engineering and PET radiochemistry have led to a new wave of experimental ImmunoPET imaging agents that are based on a range of antibody fragments and affibodies. In contrast to full antibodies, engineered affibody proteins and antibody fragments such as minibodies, diabodies, single-chain variable region fragments (scFvs), and nanobodies are much smaller but retain the essential specificities and affinities of full antibodies in addition to more desirable pharmacokinetics for imaging. Herein, recent key developments in the PET radiolabelling strategies of antibody fragments and related affibody molecules are highlighted, along with the main PET imaging applications of overexpressed antigen-associated tumours and immune cells.
Collapse
Affiliation(s)
- Ruisi Fu
- Department of ChemistryImperial College LondonExhibition RoadSouth Kensington, LondonSW7 2AZUK
- Comprehensive Cancer Imaging Centre, Department of Surgery and CancerImperial College London, Hammersmith CampusDu Cane RoadLondonW12 0NNUK
| | - Laurence Carroll
- Comprehensive Cancer Imaging Centre, Department of Surgery and CancerImperial College London, Hammersmith CampusDu Cane RoadLondonW12 0NNUK
| | - Gokhan Yahioglu
- Department of ChemistryImperial College LondonExhibition RoadSouth Kensington, LondonSW7 2AZUK
- Antikor Biopharma Ltd.StevenageSG1 2FXUK
| | - Eric O. Aboagye
- Comprehensive Cancer Imaging Centre, Department of Surgery and CancerImperial College London, Hammersmith CampusDu Cane RoadLondonW12 0NNUK
| | - Philip W. Miller
- Department of ChemistryImperial College LondonExhibition RoadSouth Kensington, LondonSW7 2AZUK
| |
Collapse
|
14
|
Zhou Z, McDougald D, Devoogdt N, Zalutsky MR, Vaidyanathan G. Labeling Single Domain Antibody Fragments with Fluorine-18 Using 2,3,5,6-Tetrafluorophenyl 6-[ 18F]Fluoronicotinate Resulting in High Tumor-to-Kidney Ratios. Mol Pharm 2018; 16:214-226. [PMID: 30427188 DOI: 10.1021/acs.molpharmaceut.8b00951] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
ImmunoPET agents are being investigated to assess the status of epidermal growth factor receptor 2 (HER2) in breast cancer patients with the goal of selecting those likely to benefit from HER2-targeted therapies and monitoring their progress after these treatments. We have been exploring the use of single domain antibody fragments (sdAbs) labeled with 18F using residualizing prosthetic agents for this purpose. In this study, we have labeled two sdAbs that bind to different domains on the HER2 receptor, 2Rs15d and 5F7, using 2,3,5,6-tetrafluorophenyl 6-[18F]fluoronicotinate ([18F]TFPFN) and evaluated their HER2 targeting properties in vitro and in vivo. The overall decay-corrected radiochemical yield for the synthesis of [18F]TFPFN-2Rs15d and [18F]TFPFN-5F7 was 5.7 ± 3.6 and 4.0 ± 2.0%, respectively. The radiochemical purity of labeled sdAbs was >95%, immunoreactive fractions were about 60%, and affinity was in the low nanomolar range. Intracellularly trapped activity from [18F]TFPFN-2Rs15d and [18F]TFPFN-5F7 in HER2-expressing SKOV-3 ovarian and BT474M1 breast carcinoma cells were similar to the sdAbs labeled using the previously validated radioiodination residualizing prosthetic agents N-succinimidyl 4-guanidinomethyl-3-[125I]iodobenzoate ([125I]SGMIB) and N-succinimidyl 3-guanidinomethyl-5-[125I]iodobenzoate ( iso-[125I]SGMIB). Intracellular activity was about 2-fold higher for radiolabeled 5F7 compared with 2Rs15d for both 18F and 125I. While tumor uptake of both [18F]TFPFN-2Rs15d and [18F]TFPFN-5F7 was comparable to those for the coadministered 125I-labeled sdAb, renal uptake of the 18F-labeled sdAbs was substantially lower. In microPET images, the tumor was clearly delineated in SKOV-3 and BT474 xenograft-bearing athymic mice with low levels of background activity in normal tissues, except the bladder. These results indicate that the [18F]TFPFN prosthetic group could be a valuable reagent for developing sdAb-based immunoPET imaging agents.
Collapse
Affiliation(s)
- Zhengyuan Zhou
- Department of Radiology , Duke University Medical Center , Durham , North Carolina 27710 , United States
| | - Darryl McDougald
- Department of Radiology , Duke University Medical Center , Durham , North Carolina 27710 , United States
| | - Nick Devoogdt
- In vivo Cellular and Molecular Imaging laboratory , Vrije Universiteit Brussel, (VUB) , 1090 , Brussels , Belgium
| | - Michael R Zalutsky
- Department of Radiology , Duke University Medical Center , Durham , North Carolina 27710 , United States
| | - Ganesan Vaidyanathan
- Department of Radiology , Duke University Medical Center , Durham , North Carolina 27710 , United States
| |
Collapse
|
15
|
Ultrasmall targeted nanoparticles with engineered antibody fragments for imaging detection of HER2-overexpressing breast cancer. Nat Commun 2018; 9:4141. [PMID: 30297810 PMCID: PMC6175906 DOI: 10.1038/s41467-018-06271-5] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/24/2018] [Indexed: 12/11/2022] Open
Abstract
Controlling the biodistribution of nanoparticles upon intravenous injection is the key to achieving target specificity. One of the impediments in nanoparticle-based tumor targeting is the inability to limit the trafficking of nanoparticles to liver and other organs leading to smaller accumulated amounts in tumor tissues, particularly via passive targeting. Here we overcome both these challenges by designing nanoparticles that combine the specificity of antibodies with favorable particle biodistribution profiles, while not exceeding the threshold for renal filtration as a combined vehicle. To that end, ultrasmall silica nanoparticles are functionalized with anti-human epidermal growth factor receptor 2 (HER2) single-chain variable fragments to exhibit high tumor-targeting efficiency and efficient renal clearance. This ultrasmall targeted nanotheranostics/nanotherapeutic platform has broad utility, both for imaging a variety of tumor tissues by suitably adopting the targeting fragment and as a potentially useful drug delivery vehicle.
Collapse
|
16
|
Uehara T, Yokoyama M, Suzuki H, Hanaoka H, Arano Y. A Gallium-67/68–Labeled Antibody Fragment for Immuno-SPECT/PET Shows Low Renal Radioactivity Without Loss of Tumor Uptake. Clin Cancer Res 2018; 24:3309-3316. [DOI: 10.1158/1078-0432.ccr-18-0123] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/05/2018] [Accepted: 04/10/2018] [Indexed: 11/16/2022]
|
17
|
Bourgeois M, Bailly C, Frindel M, Guerard F, Chérel M, Faivre-Chauvet A, Kraeber-Bodéré F, Bodet-Milin C. Radioimmunoconjugates for treating cancer: recent advances and current opportunities. Expert Opin Biol Ther 2017; 17:813-819. [DOI: 10.1080/14712598.2017.1322577] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Mickaël Bourgeois
- Department of Nuclear Medicine, University Hospital, 44093 Nantes, France
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
- Department of radiopharmacy, ARRONAX Cyclotron, Saint Herblain, France
| | - Clément Bailly
- Department of Nuclear Medicine, University Hospital, 44093 Nantes, France
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
| | - Mathieu Frindel
- Department of Nuclear Medicine, Institut de Cancérologie de l’Ouest (ICO) – Site Gauducheau, Saint Herblain, France
| | - François Guerard
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
| | - Michel Chérel
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
- Department of Nuclear Medicine, Institut de Cancérologie de l’Ouest (ICO) – Site Gauducheau, Saint Herblain, France
| | - Alain Faivre-Chauvet
- Department of Nuclear Medicine, University Hospital, 44093 Nantes, France
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
| | - Françoise Kraeber-Bodéré
- Department of Nuclear Medicine, University Hospital, 44093 Nantes, France
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
- Department of Nuclear Medicine, Institut de Cancérologie de l’Ouest (ICO) – Site Gauducheau, Saint Herblain, France
| | - Caroline Bodet-Milin
- Department of Nuclear Medicine, University Hospital, 44093 Nantes, France
- Nantes-Angers Cancer Research Center (CRCNA), University of Nantes, Nantes, France
- Department of Nuclear Medicine, Institut de Cancérologie de l’Ouest (ICO) – Site Gauducheau, Saint Herblain, France
| |
Collapse
|
18
|
Review: Receptor Targeted Nuclear Imaging of Breast Cancer. Int J Mol Sci 2017; 18:ijms18020260. [PMID: 28134770 PMCID: PMC5343796 DOI: 10.3390/ijms18020260] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 01/17/2017] [Accepted: 01/20/2017] [Indexed: 12/21/2022] Open
Abstract
Receptor targeted nuclear imaging directed against molecular markers overexpressed on breast cancer (BC) cells offers a sensitive and specific method for BC imaging. Currently, a few targets such as estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), somatostatin receptor (SSTR), and the gastrin releasing peptide receptor (GRPR) are being investigated for this purpose. Expression of these targets is BC subtype dependent and information that can be gained from lesion visualization is dependent on the target; ER-targeting radiotracers, e.g., can be used to monitor response to anti-estrogen treatment. Here we give an overview of the studies currently under investigation for receptor targeted nuclear imaging of BC. Main findings of imaging studies are summarized and (potential) purposes of lesion visualization by targeting these molecular markers are discussed. Since BC is a very heterogeneous disease and molecular target expression can vary per subtype, but also during disease progression or under influence of treatment, radiotracers for selected imaging purposes should be chosen carefully.
Collapse
|
19
|
Yoon A, Shin JW, Kim S, Kim H, Chung J. Chicken scFvs with an Artificial Cysteine for Site-Directed Conjugation. PLoS One 2016; 11:e0146907. [PMID: 26764487 PMCID: PMC4713166 DOI: 10.1371/journal.pone.0146907] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/23/2015] [Indexed: 01/08/2023] Open
Abstract
For the site-directed conjugation of chemicals and radioisotopes to the chicken-derived single-chain variable fragment (scFv), we investigated amino acid residues replaceable with cysteine. By replacing each amino acid of the 157 chicken variable region framework residues (FR, 82 residues on VH and 75 on VL) with cysteine, 157 artificial cysteine mutants were generated and characterized. At least 27 residues on VL and 37 on VH could be replaced with cysteine while retaining the binding activity of the original scFv. We prepared three VL (L5, L6 and L7) and two VH (H13 and H16) mutants as scFv-Ckappa fusion proteins and showed that PEG-conjugation to the sulfhydryl group of the artificial cysteine was achievable in all five mutants. Because the charge around the cysteine residue affects the in vivo stability of thiol-maleimide conjugation, we prepared 16 charge-variant artificial cysteine mutants by replacing the flanking residues of H13 with charged amino acids and determined that the binding activity was not affected in any of the mutants except one. We prepared four charge-variant H13 artificial cysteine mutants (RCK, DCE, ECD and ECE) as scFv-Ckappa fusion proteins and confirmed that the reactivity of the sulfhydryl group on cysteine is active and their binding activity is retained after the conjugation process.
Collapse
Affiliation(s)
- Aerin Yoon
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
| | - Jung Won Shin
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
| | - Soohyun Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyori Kim
- Cancer Research Institute, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
| | - Junho Chung
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
- * E-mail:
| |
Collapse
|
20
|
Development of anti-HER2 fragment antibody conjugated to iron oxide nanoparticles for in vivo HER2-targeted photoacoustic tumor imaging. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:2051-60. [PMID: 26238078 DOI: 10.1016/j.nano.2015.07.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/30/2015] [Accepted: 07/11/2015] [Indexed: 11/22/2022]
Abstract
UNLABELLED Photoacoustic (PA) imaging is a promising imaging modality that provides biomedical information with high sensitivity and resolution. Iron oxide nanoparticles (IONPs) have been regarded as remarkable PA contrast agents because of their low toxicity and biodegradable properties. However, IONP delivery is restricted by its modest leakage and retention in tumors. In this study, we designed IONPs (20nm, 50nm, and 100nm) conjugated with anti-HER2 moieties [whole IgG, single-chain fragment variable (scFv), and peptide] for HER2-targeted PA tumor imaging. The binding affinity, cellular uptake, and in vivo biodistribution were examined. We propose 20-nm anti-HER2 scFv-conjugated IONPs (SNP20) as a novel PA contrast agent. SNP20 demonstrated high affinity and specific binding to HER2-expressing cells; it selectively visualized HER2-positive tumors in PA imaging studies. These data indicate that SNP20 is a potential PA contrast agent for imaging of HER2-expressing tumors. FROM THE CLINICAL EDITOR Iron oxide nanoparticles have been demonstrated to be good contrast agents for tumor imaging. They may also be useful in photoacoustic (PA) imaging, which can provide high sensitivity data and image resolution. The authors here coupled iron oxide nanoparticles with anti-HER2 antibody fragment and showed significant retention of these nanoparticles in tumors. This combination may provide another option for enhanced imaging of tumors.
Collapse
|