Database for Chemicals and Biodistribution

Small molecule fluorophores: 

The physicochemical properties of each chemical, such as its chemical structure, charge distribution, distribution coefficient (logD at pH 7.4), topological polar surface area (TPSA), rotatable bonds, and H-bond acceptors/donors, were meticulously calculated using MarvinSketch (developed by ChemAxon in Budapest, Hungary). Subsequently, the images of these regions and their biodistribution were seamlessly integrated into our database using Instant JChem, another powerful tool from ChemAxon. To further analyze each biodistribution image, we employed ImageJ and subsequently uploaded the results to the InstantJChem database.

Description and References

The 800 nm zwitterionic heptamethine indocyanine NIR fluorophore ZW800-1 is developed to exhibit simultaneous bifunctionality, excellent optical properties, and high serum stability. It has remarkable in vivo properties, including no serum protein binding, rapid renal clearance, and ultralow nonspecific tissue uptake (i.e., background). ZW800-1 also provides a single carboxylic acid for the covalent conjugation to target ligands through a stable amide bond.

Angew. Chem. Int. Ed. 2011, 50, 6258.

Description and References

The optical and physicochemical stabilities of NIR in the biological and physiological environment are still a challenge. Especially, the ether linkage on the meso-carbon of heptamethine core is fragile when exposed to serum proteins or other amine-rich biomolecules. To solve such a structural limitation, a rigid carbon–carbon bond was installed onto the framework of ether-linked NIR fluorophores. The robust fluorophores displayed enhanced optical and chemical stability in various solvents and a 100% warm serum environment, with similar biodistribution and clearance as the previously developed oxygen-substituted ZW800 compounds.

RSC Adv., 2014, 4, 58762 

Description and References

OX61 is a small and hydrophilic phenoxazine with high targetability and retention to pancreatic neuroendocrine tumors. This bioengineered fluorophore permits sensitive detection of ultrasmall (<0.5 mm) ectopic tumors within a few seconds after a single bolus injection, highlighting every tumor in the pancreas from the surrounding healthy tissues with a reasonable half-life. 

iScience. 2020, 23, 101006

Description and References

Nerve preservation is an important issue during most surgeries. We evaluated a series of Oxazine derivatives to highlight various peripheral nerve structures in small and large animals. Among the targeted fluorophores, Oxazine 4 has peak emission near the NIR region, which provided a nerve-targeted signal in the brachial plexus and sciatic nerve for up to 12 h after a single intravenous injection. 

Theranostics. 2014, 4, 823

Description and References

“Phosphonated Near-Infrared Fluorophores for Biomedical Imaging of Bone” describes a new class of pendant-functionalized polymethine near-infrared fluorophores that are an alternative to conventional bisphosphonates for bone imaging. The chemical strategy we describe results in the most compact possible bifunctional molecule that has both near-infrared fluorescence and bone targeting.

Angew. Chem. Int. Ed. 2014, 53, 10668

Adv. Sci. 2019, 7, 1902267

Description and References

“Cartilage-Specific Near-Infrared Fluorophores for Biomedical Imaging” describes a novel class of small molecule structures that demonstrate high-specificity targeting to cartilage. After a single low-dose intravenous injection and a clearance time of approximately 4 h, these agents bind to all three major types of cartilage (hyaline, elastic, and fibrocartilage) and perform equally well across species.This approach might prove useful in future tissue engineering studies where transplanted neocartilage can be visualized using one NIR channel and either bone or blood vessels can be visualized with the other.

Angew. Chem. Int. Ed. 2015, 54, 8648

Adv. Sci. 2019, 7, 1902267

Description and References

A series of 700-nm and 800-nm halogenated fluorophores were developed to show high uptake by the parathyroid and thyroid glands after a single intravenous (IV) injection. By using a dual-channel NIR imaging system, we observed, in real time and with high sensitivity, the unambiguous distinction of parathyroid and thyroid glands simultaneously in the context of blood and surrounding soft tissue.

Nature Medicine. 2015, 21, 192

Description and References

The resection of regional lymph nodes in the basin of a primary tumor is of paramount importance in surgical oncology. We report an optical fluorescence technology that is capable of simultaneous mapping of pan lymph nodes (PLNs) and sentinel lymph nodes (SLNs) in the same subject. Using the dual-channel FLARE intraoperative imaging system, we could identify and resect all PLNs and SLNs simultaneously.

Theranostics. 2014, 4, 693-700

Chem. Eng. J. 2018, 340, 51-57

Description and References

“Endocrine-Specific NIR Fluorophores for Adrenal Gland Targeting” is the first to describe novel near-infrared fluorophores that are capable of targeting the adrenal glands (AG) which enable real-time image-guided surgery after only a single intravenous injection. AG are relatively small yet require definitive identification during their resection, or more commonly their avoidance, thus AG imaging helps surgeons during both open and minimally-invasive surgery.

Chem. Commun. 2016, 52, 10305

Description and References

“Intraoperative Near-Infrared Fluorescence Imaging of Thymus” reports a new technology that can visualize all the thymic tissues during thymectomies by a single intravenous injection of thymus-targeted NIR fluorophore. There are currently no thymus-specific contrast agents for biomedical imaging. Thus, finding ectopic thymic tissue during certain operations is extremely difficult. This technology would help to remove as much thymic tissue as possible in the thymectomy to achieve the satisfactory complete stable remission (CSR) rate in myasthenia gravis.

Ann. Thorac. Surg. 2017, 103, 1132

Description and References

Longitudinal tracking of living cells is crucial to understanding the mechanism of action and toxicity of cell-based therapeutics. “NIR Fluorophores for Longitudinal Cell Trafficking in Living Organisms” reports the design of fixable Cell Tracking Near-Infrared Fluorophores (CTNFs) which exhibit high extinction coefficients and quantum yields, excellent cell permeation and retention, and high stability in chemical treatment for histology. Among the tested, CTNF126 sequesters cytoplasmic membrane and fuses with lysosomes, which prevents cellular efflux and improves cellular retention during the harsh process of chemical treatment of histopathology.

Adv. Mater. 2019, 31, 1806216

Polymeric nanoparticles for drug delivery

Description and References

DFO-NP is a renal clearable nanochelator designed for iron overload therapy to treat secondary hemochromatosis. Expressing kidney-specific biodistribution and rapid renal excretion (>80% injected dose in 4 h), DFO-NP with subcutaneous injection exhibited highly improved efficacy and significantly reduced nephrotoxicity compared to the native deferoxamine (DFO).

Nat. Commun. 2019, 10, 5134

Description and References

NIR fluorophores of varying charges (+2, 0, -2, -4) were attached to manipulate the surface charge of exosomes. Zwitterionic fluorophore-labeled exosomes with zero surface charge expressed rapid renal clearance with minimum nonspecific tissue uptake, exosomes with a modified surface charge of -2 exhibited fast excretion through feces via hepatobiliary route, and those with +2 and -4 surface charges cleared through both renal and hepatobiliary routes with high nonspecific uptake in major organs (heart, lungs, liver, pancreas). This study demonstrated that unique surface properties guide the in vivo fate of exosomes, which serves as the foundation for developing tissue-specific exosome-based therapeutics.

Adv. Therap. 2019, 2, 190011

Description and References

H-Dots (ZW800-CDPL) are non-sticky and renal clearable theranostic nanoparticles that facilitate image-guided surgery and enhanced tumor targetability of anticancer drugs. H-Dots loaded with imatinib caused increased GIST specificity, improved tumor suppression, and decreased imatinib uptake into the immune system, thereby reducing drug toxicity. H-Dots are promising delivery vehicles that can potentially reduce side effects of conventional chemotherapies.

Adv. Mater. 2016, 28, 8162

Adv. Mater. 2020, 32, 1905899

Description and References

HA-IFNα-ZW800-1 is a conjugate of hyaluronate-interferon α (HA-IFNα) and biologically inert zwitterionic fluorophore ZW800-1. Designed to enhance the treatment for hepatitis C virus (HCV), HA-IFNα-ZW800-1 is labeled with ZW800-1 to investigate its pharmacokinetic properties. HA-IFNα-ZW800-1 expressed longer residence time in the blood and improved targetability to the liver compared to IFNα alone and PEGlylated IFNα. With therapeutic efficacy confirmed by the elevated level of OAS1 mRNA in the liver, HA-IFNα could also be a novel treatment for hepatocellular carcinoma.

Biomacromolecules. 2015, 16(9): 3054

Bioconjugates with targeted ligands (small molecules, peptide, proteins, and antibodies)

Description and References

Antibody binding assay for secondary antibodies (2′Ab) conjugated with ZW800-1, CW800 and Cy5.5 in MDA-MB361 (MB-361, HER2 positive) and MDA-MB-231 (MB-231, HER2 negative) human breast cancer cell lines in the presence (+) or absence (-) of the HER2 primary Ab. Her2 overexpressing MDA-MB-361 breast cancer cells showed specific membrane binding with all 3 NIR secondary antibodies, however, significantly higher background signals were observed in the Her2 negative MDA-MB-231 cells when using CW800- and Cy5.5-Ab conjugates. In addition, 2’Ab-Cy5.5 alone showed strong nonspecific binding in both breast cancer cell lines. 

Description and References

Antibody binding assay for secondary antibodies (2′Ab) conjugated with ZW800-1, CW800 and Cy5.5 in MDA-MB361 (MB-361, HER2 positive) and MDA-MB-231 (MB-231, HER2 negative) human breast cancer cell lines in the presence (+) or absence (-) of the HER2 primary Ab. Her2 overexpressing MDA-MB-361 breast cancer cells showed specific membrane binding with all 3 NIR secondary antibodies, however, significantly higher background signals were observed in the Her2 negative MDA-MB-231 cells when using CW800- and Cy5.5-Ab conjugates. In addition, 2’Ab-Cy5.5 alone showed strong nonspecific binding in both breast cancer cell lines. 

Description and References

NIR-labeled fibrinogen (FBG; FBG–ZW800-1, FBG-CW800 and FBG-Cy5.5) to visualize blot clots in rat models of bleeding in the stomach and mesenteric vessels. FBG-NIR fluorophores were obtained by adding 10 equiv of ZW800-1 NHS ester, CW800, or Cy5.5 into FBG solutions, with constant agitation for 3 h at room temperature. The reaction mixtures were purified by GFC using Econo-Pac P6 cartridges (Bio-Rad, Hercules, CA) with a flow rate of 1 mL/min (mobile phase = PBS, pH 7.4). The lower background of FBG-ZW800-1 compared to FBG-CW800 and FBG-Cy5.5 contributed to 2- to 5-fold higher CBR at 1 h postinjection in both mucosal and mesenteric sites. Control fluorophores without fibrinogen showed no accumulation at any injury site.

Nature biotechnology, 2013, 31, 148

Description and References

NIR-labeled fibrinogen (FBG; FBG–ZW800-1, FBG-CW800 and FBG-Cy5.5) to visualize blot clots in rat models of bleeding in the stomach and mesenteric vessels. FBG-NIR fluorophores were obtained by adding 10 equiv of ZW800-1 NHS ester, CW800, or Cy5.5 into FBG solutions, with constant agitation for 3 h at room temperature. The reaction mixtures were purified by GFC using Econo-Pac P6 cartridges (Bio-Rad, Hercules, CA) with a flow rate of 1 mL/min (mobile phase = PBS, pH 7.4). The lower background of FBG-ZW800-1 compared to FBG-CW800 and FBG-Cy5.5 contributed to 2- to 5-fold higher CBR at 1 h postinjection in both mucosal and mesenteric sites. Control fluorophores without fibrinogen showed no accumulation at any injury site.

Nature biotechnology, 2013, 31, 148

Description and References

NIR-labeled fibrinogen (FBG; FBG–ZW800-1, FBG-CW800 and FBG-Cy5.5) to visualize blot clots in rat models of bleeding in the stomach and mesenteric vessels. FBG-NIR fluorophores were obtained by adding 10 equiv of ZW800-1 NHS ester, CW800, or Cy5.5 into FBG solutions, with constant agitation for 3 h at room temperature. The reaction mixtures were purified by GFC using Econo-Pac P6 cartridges (Bio-Rad, Hercules, CA) with a flow rate of 1 mL/min (mobile phase = PBS, pH 7.4). The lower background of FBG-ZW800-1 compared to FBG-CW800 and FBG-Cy5.5 contributed to 2- to 5-fold higher CBR at 1 h postinjection in both mucosal and mesenteric sites. Control fluorophores without fibrinogen showed no accumulation at any injury site.

Nature biotechnology, 2013, 31, 148

Description and References

NIR-labeled fibrinogen (FBG; FBG–ZW800-1, FBG-CW800 and FBG-Cy5.5) to visualize blot clots in rat models of bleeding in the stomach and mesenteric vessels. FBG-NIR fluorophores were obtained by adding 10 equiv of ZW800-1 NHS ester, CW800, or Cy5.5 into FBG solutions, with constant agitation for 3 h at room temperature. The reaction mixtures were purified by GFC using Econo-Pac P6 cartridges (Bio-Rad, Hercules, CA) with a flow rate of 1 mL/min (mobile phase = PBS, pH 7.4). The lower background of FBG-ZW800-1 compared to FBG-CW800 and FBG-Cy5.5 contributed to 2- to 5-fold higher CBR at 1 h postinjection in both mucosal and mesenteric sites. Control fluorophores without fibrinogen showed no accumulation at any injury site.

Nature biotechnology, 2013, 31, 148

Description and References

Prostate-specific membrane antigen (PSMA) can serve as a molecular cell surface target for the detection and treatment of prostate cancer. KUE-PEG4-ZW800+3C carrying 6 net negative charges and an 18 Å spacing linker showed optimized performance in both in vitro and in vivo PSMA targeting assays.

Chem. Commun., 2017, 53, 1611

Description and References

ZW800-1C NHS ester was conjugated on ovalbumin (OVA-ZW) in PBS, pH 8.0, followed by further conjugation on SiNPs in DIW.

Adv. Healthc. Mater. 2019, 8, 1900035

Description and References

ZW800-1C NHS ester was conjugated on anti-TLR4 antibody (B, TLR4-ZW800) in PBS, pH 7.8 to target tumor associated macrophages in liver cancer.

Quant. Imaging. Med. Surg. 2019, 9, 1548

Description and References

An ideal targeted ligand should have high affinity, specificity, and selectivity to receptor-positive target tumors. To create targeted ZW800-1, IRDye800-CW, and Cy5.5, we covalently conjugated each fluorophore to a cyclic peptide consisting of cyclo(RGDyK) (cRGD), which specifically binds integrin αvβ3. Due to the starting anionic charge, cRGD-CW800 and cRGD-Cy5.5 exhibited net surface charges of -4, and a highly unbalanced (i.e., dipole-like) charge-to-hydrophobicity distribution over their surfaces. On the contrary, cRGD-ZW800-1 is very hydrophilic (logD = -7.09), has a net surface charge of 0, and has an extremely well-balanced charge distribution. As demonstrated in this study, ZW800-1 conjugates are effective NIR fluorescent tumor-targeting agents.

Nature biotechnology, 2013, 31, 148

Description and References

An ideal targeted ligand should have high affinity, specificity, and selectivity to receptor-positive target tumors. To create targeted ZW800-1, IRDye800-CW, and Cy5.5, we covalently conjugated each fluorophore to a cyclic peptide consisting of cyclo(RGDyK) (cRGD), which specifically binds integrin αvβ3. Due to the starting anionic charge, cRGD-CW800 and cRGD-Cy5.5 exhibited net surface charges of -4, and a highly unbalanced (i.e., dipole-like) charge-to-hydrophobicity distribution over their surfaces. On the contrary, cRGD-ZW800-1 is very hydrophilic (logD = -7.09), has a net surface charge of 0, and has an extremely well-balanced charge distribution. As demonstrated in this study, ZW800-1 conjugates are effective NIR fluorescent tumor-targeting agents.

Nature biotechnology, 2013, 31, 148

Description and References

An ideal targeted ligand should have high affinity, specificity, and selectivity to receptor-positive target tumors. To create targeted ZW800-1, IRDye800-CW, and Cy5.5, we covalently conjugated each fluorophore to a cyclic peptide consisting of cyclo(RGDyK) (cRGD), which specifically binds integrin αvβ3. Due to the starting anionic charge, cRGD-CW800 and cRGD-Cy5.5 exhibited net surface charges of -4, and a highly unbalanced (i.e., dipole-like) charge-to-hydrophobicity distribution over their surfaces. On the contrary, cRGD-ZW800-1 is very hydrophilic (logD = -7.09), has a net surface charge of 0, and has an extremely well-balanced charge distribution. As demonstrated in this study, ZW800-1 conjugates are effective NIR fluorescent tumor-targeting agents.

Nature biotechnology, 2013, 31, 148