Metal complex catalysis within biological systems is largely limited to cell and bacterial systems. In this work, a glycoalbumin-Au complex was designed and developed that enables organ-specific, localized propargyl ester amidation with nearby proteins within live mice. The targeted reactivity can be imaged through the use of Cy7.5- and TAMRA-linked propargyl ester based fluorescent probes. This targeting system could enable the exploitation of other metal catalysis strategies for biomedical and clinical applications.

Metal complex catalysis within biological systems is largely limited to cell and bacterial systems.I nt his work, ag lycoalbumin-Au III complex was designed and developed that enables organ-specific,l ocalized propargyl ester amidation with nearby proteins within live mice.T he targeted reactivity can be imaged through the use of Cy7.5-and TAMRA-linked propargyl ester based fluorescent probes.This targeting system could enable the exploitation of other metal catalysis strategies for biomedical and clinical applications.

This work represents the first broad study of testing diverse heterogenous glycoconjugates (7 different glycoalbumins) for their differential in vivo binding (11 different cancer cell types) in both cell- and animal-based studies. As a result, various changes in biodistribution, excretion, and even tumor adhesion were observed.

Structurally well‐defined heterogeneous N‐glycoclusters are prepared on albumin via a double click procedure. The number of glycan molecules present, in addition to the spatial arrangement of glycans in the heterogeneous glycoclusters, plays an important role in the in vivo kinetics and organ‐selective accumulation through glycan pattern recognition mechanisms.

Natural glycoconjugates that form glycocalyx play important roles in various biological processes based on cell surface recognition through pattern recognition mechanisms. This work represents a new synthesisbased screening strategy to efficiently target the cancer cells by higherorder glycan pattern recognition in both cells and intact animals (mice). The use of the very fast, selective, and effective RIKEN click reaction (6π-azaelectrocyclization of unsaturated imines) allows to synthesize and screen various structurally well-defined glycoalbumins containing two and eventually four different N-glycan structures in a very short time. The importance of glycan pattern recognition is exemplified in both cell-and mouse-based experiments. The use of pattern recognition mechanisms for cell targeting represents a novel and promising strategy for the development of diagnostic, prophylactic, and therapeutic agents for various diseases including cancers.

This study presents the early framework of selective cell tagging (SeCT) therapy, which is the concept of preferentially labeling specific cells in vivo with chemical moieties that can elicit a therapeutic response. Using glycosylated artificial metalloenzyme (GArM)–based protein labeling, this study reports two separate functional strategies. In one approach, early tumor onset can be suppressed by tagging cancer cells in living mice with an integrin-blocking cyclic–Arg-Gly-Asp (cRGD) moiety, thereby disrupting cell adhesion onto the extracellular matrix. In another approach, tumor growth in mice can be reduced by tagging with a cytotoxic doxorubicin moiety. Subsequent cell death occurs following internalization and drug release. Overall, experiments have shown that mouse populations receiving the mixture of SeCT labeling reagents exhibited a significant delay/reduction in tumor onset and growth compared with controls. Highlighting its adaptability, this work represents a foundational step for further development of SeCT therapy and its potential therapeutic applications.

Advanced glycation end products (AGEs) are associated with various diseases, especially during aging and the development of diabetes and uremia. To better understand these biological processes, investigation of the in vivo kinetics of AGEs, i.e., analysis of trafficking and clearance properties, was carried out by molecular imaging. Following the preparation of Cy7.5-labeled AGE-albumin and intravenous injection in BALB/cA-nu/nu mice, noninvasive fluorescence kinetics analysis was performed. In vivo imaging and fluorescence microscopy analysis revealed that non-enzymatic AGEs were smoothly captured by scavenger cells in the liver, i.e., Kupffer and other sinusoidal cells, but were unable to be properly cleared from the body. Overall, these results highlight an important link between AGEs and various disorders associated with them, which may serve as a platform for future research to better understand the processes and mechanisms of these disorders.

In the field of molecular imaging, selectivity for target cells is a key determinant of the degree of imaging contrast. Previously, we developed a pre-targeted method by which target cells could be selectively imaged using a labeled N-glycan that was ligated in situ with an integrintargeted cyclic RGD peptide on the cell surface. Here we demonstrate the power of our method in discriminating various cancerous and non-cancerous cells that cannot be distinguished using conventional RGD ligands. Using four cyclic RGDyK peptides with various linker lengths with five N-glycans, we identify optimal combinations to discriminate six types of α v β 3 integrin-expressing cells on 96-well plates. The optimal combinations of RGD and Nglycan ligands for the target cells are fingerprinted on the plates, and then used to selectively image tumors in xenografted mouse models. Using this method, various N-glycan molecules, even those with millimolar affinities for their cognate lectins, could be used for selective cancer cell differentiation.