Unlabelled: An ideal multiphoton fluorescent nanoprobe should combine a nanocrystal with the largest possible two-photon absorption cross section (TPACS) and the smallest highly specific recognition molecules bound in an oriented manner. CdSe/ZnS quantum dots (QDs) conjugated to 13-kDa single-domain antibodies (sdAbs) derived from camelid IgG or streptavidin have been used as efficient two-photon excitation (TPE) probes for carcinoembryonic antigen (CEA) imaging on normal human appendix and colon carcinoma tissue. The TPACS for some conjugates was higher than 49,000 GM (Goeppert-Mayer units), considerably exceeding that of organic dyes being close to the theoretical value of 50,000 GM calculated for CdSe QDs. The ratio of sdAb-QD emission to the autofluorescence for 800 nm TPE was 40 times higher than that for 457.9 nm one-photon excitation. TPE ensures a clear discrimination of CEA-overexpressing tumor areas from normal tissue. Oriented sdAb-QD conjugates are bright specific labels for detecting low concentrations of antigens using multiphoton microscopy.
From The Clinical Editor: This study demonstrates carcinoembryonic antigen imaging on normal human appendix and colon carcinoma tissue utilizing CdSe/ZnS quantum dots conjugated to streptavidin or to 13-kDa single-domain antibodies as efficient two-photon excitation probes.
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http://dx.doi.org/10.1016/j.nano.2014.05.014 | DOI Listing |
Sci Adv
January 2025
Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Small extracellular vesicles (sEVs) are nanosized vesicles. Death receptor 5 (DR5) mediates extrinsic apoptosis. We engineer DR5 agonistic single-chain variable fragment (scFv) expression on the surface of sEVs derived from natural killer cells.
View Article and Find Full Text PDFMatrix Biol
February 2025
Department of Life Sciences, Ewha Womans University, Seoul 03760, South Korea. Electronic address:
Disrupting the interaction between matrix metalloproteinase-7 (MMP-7) and syndecan-2 (SDC-2) can yield anticancer effects in colon cancer cells. Here, a single-chain variable fragment (scFv) targeting the pro-domain of MMP-7 was generated as a potential candidate anticancer agent. Among the generated scFvs, those designated 1B7 and 1C3 showed the strongest abilities to inhibit the ability of MMP-7 pro-domain to directly interact with SDC-2 in vitro and decrease the cancer activities of human HT29 colon adenocarcinoma cells.
View Article and Find Full Text PDFJ Immunother Cancer
December 2024
Department of Clinical Laboratory, Affiliated Hangzhou First People's Hospital, School of Medicine, Westlake University, Hangzhou, Zhejiang, China
Objective: Targeting CD47 for cancer immunotherapy has been studied in many clinical trials for the treatment of patients with advanced tumors. However, this therapeutic approach is often hampered by on-target side effects, physical barriers, and immunosuppressive tumor microenvironment (TME).
Methods: To improve therapeutic efficacy while minimizing toxicities, we engineered an oncolytic vaccinia virus (OVV) encoding an anti-CD47 nanobody (OVV-αCD47nb).
Nat Commun
January 2025
Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
Influenza remains a persistent global health challenge, largely due to the virus' continuous antigenic drift and occasional shift, which impede the development of a universal vaccine. To address this, the identification of broadly neutralizing antibodies and their epitopes is crucial. Nanobodies, with their unique characteristics and binding capacity, offer a promising avenue to identify such epitopes.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
Addressing the frequent emergence of SARS-CoV-2 mutant strains requires therapeutic approaches with innovative neutralization mechanisms. The targeting of multivalent nanobodies can enhance potency and reduce the risk of viral escape, positioning them as promising drug candidates. Here, the synergistic mechanisms of the two types of nanobodies are investigated deeply.
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