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Abstract: Dual‐labeled biomolecules constitute a new generation of bioconjugates with promising applications in therapy and diagnosis. Unfortunately, the development of these new families of biologics is hampered by the technical difficulties associated with their construction. In particular, the site specificity of the conjugation is critical as the number and position of payloads can have a dramatic impact on the pharmacokinetics of the bioconjugate. Herein, we introduce dichlorotetrazine as a trivalent platform for the selective double modification of proteins on cysteine residues. This strategy is applied to the dual labeling of albumin with a macrocyclic chelator for nuclear imaging and a fluorescent probe for fluorescence imaging. [ABSTRACT FROM AUTHOR]

Abstract: Dual‐labeled biomolecules constitute a new generation of bioconjugates with promising applications in therapy and diagnosis. Unfortunately, the development of these new families of biologics is hampered by the technical difficulties associated with their construction. In particular, the site specificity of the conjugation is critical as the number and position of payloads can have a dramatic impact on the pharmacokinetics of the bioconjugate. Herein, we introduce dichlorotetrazine as a trivalent platform for the selective double modification of proteins on cysteine residues. This strategy is applied to the dual labeling of albumin with a macrocyclic chelator for nuclear imaging and a fluorescent probe for fluorescence imaging. [ABSTRACT FROM AUTHOR]

A DOTA derivative that contains an anhydride group was readily synthesized by reacting DOTAGA with acetic anhydride and its reactivity was investigated. Opening the anhydride with propylamine led to the selective formation of one of two possible regioisomers. The structure of the obtained isomer was unambiguously determined by 1D and 2D NMR experiments, including COSY, HMBC, and NOESY techniques. This bifunctional chelating agent offers a convenient and attractive approach for labeling biomolecules and, more generally, for the synthesis of a large range of DOTA derivatives. The scope of the reaction was extended to prepare DOTA-like compounds that contained various functional groups, such as isothiocyanate, thiol, ester, and amino acid moieties. This versatile building block was also used for the synthesis of a bimodal tag for SPECT or PET/optical imaging. [ABSTRACT FROM AUTHOR]

Introduction: Traditional advance care planning focuses on end‐of‐life planning in the context of a certain or imminent death. It is not tailored for serious illness planning, where the 'death' outcome is uncertain. The Plan Well Guide™ (PWG) is a decision aid that empowers lay persons to better understand different types of care and prepares them, and their substitute decision‐makers, to express both their authentic values and informed treatment preferences in anticipation of serious illness. A cultural adaptation was necessary to make the material suitable to the context of Quebec, a French‐speaking Canadian province. Methods: We engaged lay collaborators and experts in a panel, involving three phases of consultation and data collection. These included an online questionnaire, focused interviews and virtual focus groups that identified elements within the francophone PWG affecting its feasibility, adaptation and integration, as well as items that should be modified. Results: We engaged 22 collaborators between April and September 2021. The majority (82%) ranked the first translation as good or very good; most (70%) stated that they would recommend the final adaptation. Both lay and expert panel members suggested simplifying the language and framing the tool better within the context of other advance medical planning processes in Quebec. Translation was considered in a cultural context; the challenges identified by the research team or by collaborators were addressed during the focus group. Examples of wording that required discussion include translating 'getting the medical care that's right for you' when referring to the PWG's goal. An equivalent expression in the French translation was believed to invoke religious associations. Using the term 'machines' to describe life‐sustaining treatments was also deliberated. Conclusion: Our collaborative iterative adaptation process led to the first French advanced serious illness planning tool. How acceptable and user‐friendly this French adaptation of the PWG is in various Canadian French‐speaking environments requires further study. Contribution: We organized a focus group inviting both lay collaborators and experts to contribute to the interpretation of the results of the previous phases. This choice allowed us to add more value to our results and to the final PWG in French. [ABSTRACT FROM AUTHOR]

The effective synthesis of extended conjugated N, N-dialkylamino- nor-dihydroxanthene-based fluorophores is described from diversely functionalized salicylic aldehydes. The access to these original fluorescent derivatives proceeded in two steps through a one-pot construction of the unusual nor-dihydroxanthene ( nor-DHX) scaffold followed by a diversification step providing a wide variety of nor-DHX-hemicyanine fused dyes emitting in the range of 730-790 nm. The versatility of our approach has enabled a further extension to the late-stage introduction of negatively/positively charged polar groups onto their terminal nitrogen heterocyclic subunit, thereby giving access to the first water-soluble and/or bioconjugatable members of this emerging class of NIR fluorophores. Our water-solubilizing method is easily implementable, and the nor-DHX-hemicyanine skeleton maintains satisfying fluorescence quantum yields (5-20 %) under physiological conditions. Finally, the bioconjugation ability of fluorescent derivatives bearing a free carboxylic acid was demonstrated through the covalent labeling of a model protein, namely, bovine serum albumin. [ABSTRACT FROM AUTHOR]

Members of a series of boron difluoride complexes with 3-(heteroaryl)-2-iminocoumarin ligands bearing both a phenolic hydroxyl group (acting as a fluorogenic center) and an N-aryl substituent (acting as a stabilizing moiety) have been synthesized in good yields by applying a straightforward two-step method. These novel fluorogenic dyes belong to the family of 'Boricos' (D. Frath et al., Chem. Commun.­ 2013, 49, 4908-4910) and are the first examples of phenol-based fluorophores of which the photophysical properties in the green-yellow spectral range are dramatically improved by N, N-chelation of a boron atom. Modulation of their fluorescence properties through reversible chemical modification of their phenol moieties has been demonstrated by the preparation of the corresponding 2,4-dinitrophenyl (DNP) ethers, which led to a dramatic 'OFF-ON' fluorescence response upon reaction with thiols. Additionally, to expand the scope of these '7-hydroxy-Borico' derivatives, particularly in biolabeling, amine or carboxylic acid functionalities amenable to (bio)conjugation have been introduced within their scaffold. Their utility has been demonstrated in the preparation of fluorescent bovine serum albumin (BSA) conjugates and 'Borico'-DOTA-like scaffolds in an effort to design novel monomolecular multimodal fluorescence- radioisotope imaging agents. [ABSTRACT FROM AUTHOR]

A new generation of monomolecular imaging probes (MOMIP) based on a distyryl-BODIPY (BODIPY=boron-dipyrromethene) coupled with three DOTA macrocycles has been prepared (DOTA=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). The MOMIP presents good fluorescence properties and is very stable in serum. The bimodal probe was conjugated to trastuzumab, and an optical in vivo study showed high accumulation of the imaging agent at the tumor site. 111In radiometallation of the bioconjugate was performed in high radiochemical yield, highlighting the potential of this new BODIPY-chelators derivative as a bimodal imaging probe. [ABSTRACT FROM AUTHOR]

In molecular imaging, multimodal imaging agents can provide complementary information, for improving the accuracy of disease diagnosis or enhancing patient management. In particular, optical/nuclear imaging may find important preclinical and clinical applications. To simplify the preparation of dual-labeled imaging agents, we prepared versatile monomolecular multimodal imaging probe (MOMIP) platforms containing both a fluorescent dye (BODIPY) and a metal chelator (polyazamacrocycle). One of the MOMIP was conjugated to a cyclopeptide (i.e., octreotide) and radiolabeled with 111In. In vitro and in vivo studies of the resulting bioconjugate were conducted, highlighting the potential of these BODIPY-based bimodal probes. This work also confirmed that the biovector and/or the bimodal probes must be chosen carefully, due to the impact of the MOMIP on the overall properties of the resulting imaging agent. [ABSTRACT FROM AUTHOR]

The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near λ=600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of fluorescence quantum yield (30 % to 59 %) for these bioconjugates are obtained. The photostability of these DPP dyes is considerably greater than that of fluorescein under the same irradiation conditions. Remarkably low detection limits between 80 and 300 molecules/μm2 were found for the BSA bioconjugates by fluorescence imaging with a epifluorescence microscope. [ABSTRACT FROM AUTHOR]

The preparation of highly water-soluble and strongly fluorescent diketopyrrolopyrrole (DPP) dyes using an unusual taurine-like sulfonated linker has been achieved. Exchanging a phenyl for a thienyl substituent shifts the emission wavelength to near λ=600 nm. The free carboxylic acid group present in these new derivatives was readily activated and the dyes were subsequently covalently linked to a model protein (bovine serum albumin; BSA). The bioconjugates were characterized by electronic absorption, fluorescence spectroscopy and MALDI-TOF mass spectrometry, thus enabling precise determination of the labeling density (ratio DPP/BSA about 3 to 8). Outstanding values of fluorescence quantum yield (30 % to 59 %) for these bioconjugates are obtained. The photostability of these DPP dyes is considerably greater than that of fluorescein under the same irradiation conditions. Remarkably low detection limits between 80 and 300 molecules/μm2 were found for the BSA bioconjugates by fluorescence imaging with a epifluorescence microscope. [ABSTRACT FROM AUTHOR]