| 1. |
- Deyev, Sergey M., et al.
(författare)
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Effect of a radiolabel biochemical nature on tumor-targeting properties of EpCAM-binding engineered scaffold protein DARPin Ec1
- 2020
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Ingår i: International Journal of Biological Macromolecules. - : ELSEVIER. - 0141-8130 .- 1879-0003. ; 145, s. 216-225
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Tidskriftsartikel (refereegranskat)abstract
- Radionuclide-based imaging of molecular therapeutic targets might facilitate stratifying patients for specific biotherapeutics. New type of imaging probes, based on designed ankyrin repeat proteins (DARPins), have demonstrated excellent contrast of imaging of human epidermal growth factor type 2 (HER2) expression in preclinical models. We hypothesized that labeling approaches, which result in lipophilic radiometabolites (non-residualizing labels), would provide the best imaging contrast for DARPins that internalize slowly after binding to cancer cells. The hypothesis was tested using DARPin Ec1 that binds to epithelial cell adhesion molecule (EpCAM). EpCAM is a promising therapeutic target. Ec1 was labeled with I-125 using two methods to obtain the non-residualizing labels, while residualizing labels were obtained by labeling it with Tc-99m. All labeled Ec1 variants preserved target specificity and picomolar binding affinity to EpCAM-expressing pancreatic adenocarcinoma BxPC-3 cells. In murine models, all the variants provided similar tumor uptake. However, I-125-PIB-H-6-Ec1 had noticeably lower retention in normal tissues, which provided appreciably higher tumor-to-organ ratios. Furthermore, I-125-PIB-H-6-Ec1 demonstrated the highest imaging contrast in preclinical models than any other EpCAM-imaging agent tested so far. In conclusion, DARPin Ec1 in combination with a non-residualizing label is a promising probe for imaging EpCAM expression a few hours after injection.
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| 2. |
- Günther, Tyran, et al.
(författare)
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Redox-site accessibility of composites containing a 2D redox-active covalent organic framework : from optimization to application
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 11:26, s. 13923-13931
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Tidskriftsartikel (refereegranskat)abstract
- Redox-active covalent organic frameworks (RACOFs) can be employed in various functional materials and enesrgy applications. A crucial performance or efficiency indicator is the percentage of redox centres that can be utilised. Herein, the term redox-site accessibility (RSA) is defined and shown to be an effective metric for developing and optimising a 2D RACOF (viz., TpOMe-DAQ made from 2,4,6-trimethoxy-1,3,5-benzenetricarbaldehyde [TpOMe] and 2,6-diaminoanthraquinone [DAQ]) as an anode material for potential organic-battery applications. Pristine TpOMe-DAQ utilises only 0.76% of its redox sites, necessitating the use of conductivity-enhancement strategies such as blending it with different conductive carbons, or performing in situ polymerisation with EDOT (3,4-ethylenedioxythiophene) to form a conductive polymer. While conductive carbon-RACOF composites showed a modest RSA improvement of 4.0%, conductive polymer-RACOF composites boosted the redox-site usage (RSA) to 90% at low mass loadings. The material and electrochemical characteristics of the conductive polymer-RACOF composite containing more-than-necessary conductive polymer showed a reduced surface area but almost identical electrochemical behaviour, compared to the optimal ratio. The high RSA of the optimally loaded composite was replicated in a RACOF-air battery with over 90% active redox sites. We believe that the reported approach and methods, which can be employed on a milligram scale, could serve as a general guide for the electrification and characterisation of RACOFs, as well as for other redox-active porous polymers.
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| 3. |
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| 4. |
- Nordlund, Michael, et al.
(författare)
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Catenane dimer formation in tether-assisted trans-bis-pyrrolidination of [60]fullerene
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Trans-bis-pyrrolidination of [60]fullerene employing a new bis-aldehyde tether with appended octadecyloxy substituents proceeded to give the desired product as well as catenane dimers. For pyrrolidinations employing sarcosine, the products were separable, and characterisation by NMR spectroscopy, including diffusion-ordered spectroscopy (DOSY), provided unambiguous proof that the high-mass product was a symmetric non-covalent catenane. No catenane or other high-mass products were observed for reactions employing a tether without the octadecyloxy substituents.
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| 5. |
- Vorobyeva, Anzhelika, et al.
(författare)
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Indirect Radioiodination of DARPin G3 Using N-succinimidyl-Para-Iodobenzoate Improves the Contrast of HER2 Molecular Imaging
- 2019
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 20:12
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Tidskriftsartikel (refereegranskat)abstract
- Radionuclide molecular imaging of human epidermal growth factor receptor 2 (HER2) in breast and gastroesophageal cancer might be used to stratify patients for HER2-targeted therapy as well as monitor treatment response and disease progression. Designed ankyrin repeat proteins (DARPins) are small engineered scaffold proteins with favorable properties for molecular imaging. Herein we compared two methods for labeling the anti-HER2 DARPin (HE)(3)-G3, direct and indirect radioiodination. We hypothesized that the use of N-succinimidyl-para-iodobenzoate (SPIB) for radioiodination would facilitate the clearance of radiometabolites and improve the contrast of imaging. Both radiolabeled (HE)(3)-G3 variants preserved their binding specificity and high affinity to HER2-expressing cells. The specificity of tumor targeting in vivo was also demonstrated. A biodistribution comparison of [I-125]I-(HE)(3)-G3 and [I-125]I-PIB-(HE)(3)-G3, in mice bearing HER2 expressing SKOV3 xenografts, showed rapid clearance of [I-125]I-PIB-(HE)(3)-G3 from normal organs and tissues and low accumulation of activity in organs with NaI-symporter expression. Both radiolabeled (HE)(3)-G3 variants had equal tumor uptake. Consequently, the indirect label provided higher tumor-to-blood and tumor-to-organ ratios compared with the direct label. Comparative Single Photon Emission Computed Tomography (SPECT)/CT imaging of HER2 expression in SKOV3 xenografts, using both radiolabeled DARPins, demonstrated the superior imaging contrast of the indirect label. Indirect radioiodination of (HE)(3)-G3 using SPIB could be further applied for SPECT and PET imaging with iodine-123 and iodine-124.
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