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Hepatocellular carcinoma (HCC) is a malignant tumor associated with high morbidity and mortality rates. In many non-prostate solid tumors such as HCC, prostate-specific membrane antigens (PSMA) are overexpressed in tumor-associated endothelial cells. Therefore, the aim of this study was to evaluate the performance of [sup68/supGa]Ga-PSMA-617 PET imaging on HCC with different animal models, including cell line-derived xenografts (CDX) and patient-derived xenografts (PDX), and to explore its mechanisms of function.[sup68/supGa]Ga-PSMA-617 was prepared. The expression level of PSMA in two human hepatocellular cancer cells (HepG2 and HuH-7) was evaluated, and the cellular uptakes of [sup68/supGa]Ga-PSMA-617 were assayed. HepG2 and HuH-7 subcutaneous xenograft models, HepG2 orthotopic xenograft models, and four different groups of PDX models were prepared. Preclinical pharmacokinetics and performance of [sup68/supGa]Ga-PSMA-617 were evaluated in different types of HCC xenografts models using small animal PET and biodistribution studies.Low PSMA expression level of HepG2 and HuH-7 cells was observed, and the cellular uptake and blocking study confirmed the non-specificity of the PSMA-targeted probe binding to HepG2 and HuH-7 cells. In the subcutaneous xenograft models, the tumor uptakes at 0.5 h were 0.76 ± 0.12%ID/g (HepG2 tumors) and 0.78 ± 0.08%ID/g (HuH-7 tumors), respectively, which were significantly higher than those of the blocking groups (0.23 ± 0.04%ID/g and 0.20 ± 0.04%ID/g, respectively). In the orthotopic xenograft models, PET images clearly displayed the tumor locations based on the preferential accumulation of [sup68/supGa]Ga-PSMA-617 in tumor tissue versus normal liver tissue, suggesting the possibility of using [sup68/supGa]Ga-PSMA-617 PET imaging to detect primary HCC lesions in deep tissue. In the four different groups of HCC PDX models, PET imaging with [sup68/supGa]Ga-PSMA-617 provided clear tumor uptakes with prominent tumor-to-background contrast, further demonstrating its potential for the clinical imaging of PSMA-positive HCC lesions. The staining of tumor tissue sections with CD31- and PSMA-specific antibodies visualized the tumor-associated blood vessels and PSMA expression on endothelial cells in subcutaneous, orthotopic tissues, and PDX tissues, confirming the imaging with [sup68/supGa]Ga-PSMA-617 might be mediated by targeting tumor associated endothelium.In this study, in vivo PET on different types of HCC xenograft models illustrated high uptake within tumors, which confirmed that [sup68/supGa]Ga-PSMA-617 PET may be a promising imaging modality for HCC by targeting tumor associated endothelium.

Figure S1. Correlation of TACSTD2 with Prostate Cancer Cell Surface Markers.

Purpose:Men with metastatic castration-resistant prostate cancer (mCRPC) frequently develop resistance to androgen receptor signaling inhibitor (ARSI) treatment; therefore, new therapies are needed. Trophoblastic cell-surface antigen (TROP-2) is a transmembrane protein identified in prostate cancer and overexpressed in multiple malignancies. TROP-2 is a therapeutic target for antibody–drug conjugates (ADC).Experimental Design:TROP-2 gene (TACSTD2) expression and markers of treatment resistance from prostate biopsies were analyzed using data from four previously curated cohorts of mCRPC (n = 634) and the PROMOTE study (dbGaP accession phs001141.v1.p1, n = 88). EPCAM or TROP-2–positive circulating tumor cells (CTC) were captured from peripheral blood for comparison of protein (n = 15) and gene expression signatures of treatment resistance (n = 40). We assessed the efficacy of TROP-2–targeting agents in a mouse xenograft model generated from prostate cancer cell lines.Results:We demonstrated that TACSTD2 is expressed in mCRPC from luminal and basal tumors but at lower levels in patients with neuroendocrine prostate cancer. Patients previously treated with ARSI showed no significant difference in TACSTD2 expression, whereas patients with detectable AR-V7 expression showed increased expression. We observed that TROP-2 can serve as a cell surface target for isolating CTCs, which may serve as a predictive biomarker for ADCs. We also demonstrated that prostate cancer cell line xenografts can be targeted specifically by labeled anti–TROP-2 agents in vivo.Conclusions:These results support further studies on TROP-2 as a therapeutic and diagnostic target for mCRPC.

Supplementary methods. Supplementary Table S1. Antibodies used in immune cell characterization by flow cytometry. Supplementary Table S2. PK parameters of ALT-803 administered to cynomolgus monkeys. Supplementary Table S3. Representative clinical characteristics of cynomolgus monkeys following 4 weekly doses of ALT-803 administration (study day 26). Supplementary Table S4. Incidence of major histopathologic findings in cynomolgus monkeys following 4 weekly doses of ALT-803 administration (study day 26). Supplementary Figure 1. Comparative binding of ALT-803 to IL-15 receptors on mouse, cynomolgus monkey, and human immune cells.

Movie S3 from Dual Targeting of Tissue Factor and CD105 for Preclinical PET Imaging of Pancreatic Cancer

Determination of NOTA to Fab Fragment Ratio

This study used integrin αvβ3 as a target for tumor-specific delivery of tumor necrosis factor-α (TNF). The fusion protein RGD4C-TNF bound specifically to αvβ3 as evidenced by cell receptor binding assay and noninvasive micro-positron emission tomography imaging. 64Cu-DOTA-RGD4C-TNF had significantly higher activity accumulation in integrin-positive tumors (U87MG and MDA-MB-435) but not in integrin-negative tumors (C6) compared with 64Cu-DOTA-TNF. The magnitude of tumor uptake of 64Cu-DOTA-RGD4C-TNF correlated well with the αvβ3 level (U87MG > MDA-MB-435 > C6). Tumor accumulation of 64Cu-DOTA-RGD4C-TNF could be effectively blocked by c(RGDyK) peptide in αvβ3-positive tumor models, suggesting αvβ3 specificity of RGD4C-TNF fusion protein in vivo. Furthermore, although the fusion of RGD4C moiety to TNF had little effect on the bioactivity and cytotoxicity of RGD4C-TNF compared with TNF in cell culture, RGD4C-TNF was significantly more potent than TNF in inhibiting orthotopic MDA-MB-435 tumor growth. Ex vivo tissue staining confirmed specific cytotoxicity of RGD4C-TNF against integrin-positive tumor cells and tumor vasculature. [Mol Cancer Ther 2008;7(5):1044–53]

Supplementary Figure 1. Purification of heterodimer after click chemistry conjugation of ALT-836-Fab and TRC105-Fab Supplementary Figure 2. MALDI-TOF mass spectra of ALT-836-Fab: [M+H]+ = 47266.0, TRC105-Fab: [M+H]+ = 47454.7, and heterodimer: exact [M+H]+ = 103504.0. Supplementary Figure 3. Flow cytometry analysis in BXPC-3 after 1 h incubation of FITC-Fab conjugates for the comparison of their in vitro targeting Supplementary Figure 4. Radiolabeling efficiency at different copper: immunoconjugate ratios were used to determine the number of NOTA per antibody fragment molecule Supplementary Figure 5. PET imaging and biodistribution of 64CuCl2 in BXPC-3 tumor-bearing mice. Supplementary Figure 6. PET imaging and quantitative ROI analysis of 64Cu-NOTA-heterodimer with TF and CD105 dual-blocking in BXPC-3 tumor-bearing mice. Supplementary Figure 7. Coronal images and transverse PET/CT images of normal nude mice at 3, 15, 24 and 30 h following injection of 64Cu-NOTA-heterodimer Supplementary Figure 8. PET ROI-derived quantification of 64Cu-NOTA-heterodimer uptake in the tumor, normal pancreas, blood pool, liver, kidney and muscle at 3 h, 15 h, 24 h and 30 h p.i. of the tracer

Supplementary Figure from Integrin-targeted imaging and therapy with RGD4C-TNF fusion protein

Supplementary Figures S1-S2 from Integrin αvβ3-Targeted Radioimmunotherapy of Glioblastoma Multiforme

Purpose: Pancreatic adenocarcinoma is a highly aggressive cancer, currently treated with limited success and dismal outcomes. New diagnostic and treatment strategies offer the potential to reduce cancer mortality. Developing highly specific noninvasive imaging probes for pancreatic cancer is essential to improving diagnostic accuracy and monitoring therapeutic intervention.Experimental Design: A bispecific heterodimer was synthesized by conjugating an anti-tissue factor (TF) Fab with an anti-CD105 Fab, via the bio-orthogonal “click” reaction between tetrazine (Tz) and trans-cyclooctene (TCO). The heterodimer was labeled with 64Cu for PET imaging of nude mice bearing BXPC-3 xenograft and orthotopic pancreatic tumors.Results: PET imaging of BXPC-3 (TF/CD105+/+) xenograft tumors with 64Cu-labeled heterodimer displayed significantly enhanced tumor uptake (28.8 ± 3.2 %ID/g; n = 4; SD) at 30 hours postinjection, as compared with each of their monospecific Fab tracers (12.5 ± 1.4 and 7.1 ± 2.6 %ID/g; n = 3; SD). In addition, the activity–concentration ratio allowed for effective tumor visualization (tumor/muscle ratio 75.2 ± 9.4 at 30 hours postinjection.; n = 4; SD). Furthermore, 64Cu-NOTA-heterodimer enabled sensitive detection of orthotopic pancreatic tumor lesions with an uptake of 17.1 ± 4.9 %ID/g at 30 hours postinjection and tumor/muscle ratio of 72.3 ± 46.7.Conclusions: This study demonstrates that dual targeting of TF and CD105 provided synergistic improvements in binding affinity and tumor localization of the heterodimer. Dual-targeted imaging agents of pancreatic and other cancers may assist in diagnosing pancreatic malignancies as well as reliable monitoring of therapeutic response. Clin Cancer Res; 22(15); 3821–30. ©2016 AACR.

Supplementary Figure 1 from Noninvasive De novo Imaging of Human Embryonic Stem Cell–Derived Teratoma Formation

Supplementary Methods and Figure Legend from Noninvasive De novo Imaging of Human Embryonic Stem Cell–Derived Teratoma Formation

Teratoma formation can be a serious drawback after the therapeutic transplantation of human embryonic stem (hES) cells. Therefore, noninvasive imaging of teratomas could be a valuable tool for monitoring patients undergoing hES cell treatment. Here, we investigated the angiogenic process within teratomas derived from hES cells and now report the first example of using 64Cu-labeled RGD tetramer (64Cu-DOTA-RGD4) for positron emission tomography imaging of teratoma formation by targeting αvβ3 integrin. H9 hES cells (2 × 106), stably expressing firefly luciferase, and enhanced green fluorescence protein (Fluc-eGFP) were injected into adult nude mice (n = 12) s.c. Eight weeks after transplantation, these hES cell grafts evolved into teratomas as confirmed by longitudinal bioluminescence imaging. Under micropositron emission tomography imaging, 2-deoxy-2-[18F]fluoro-D-glucose and 3′-deoxy-3′-[18F]-fluorothymidine both failed to detect hES cell–derived teratomas (0.8 ± 0.5 versus 1.1 ± 0.4 %ID/g, respectively; P = not significant versus background signals). By contrast, 64Cu-DOTA-RGD4 revealed specific and prominent uptake in vascularized teratoma and significantly lower uptake in control tumors (human ovarian carcinoma 2008 cell line), which had low intergrin expression (10.1 ± 3.4 versus 1.4 ± 1.2 %ID/g; P < 0.01). Immunofluorescence staining of CD31 and β3 integrin also supported our in vivo imaging results (P < 0.05). Moreover, we found that the cells dissociated from teratomas showed higher αvβ3 integrin expression than the 2008 cells. In conclusion, by targeting αvβ3 integrin, we successfully showed the ability of 64Cu-DOTA-RGD4 to noninvasively visualize teratoma formation in vivo for the first time. [Cancer Res 2009;69(7):2709–13]

The knowledge of interactions among functional proteins helps researchers understand disease mechanisms and design potential strategies for treatment. As a general approach, the fluorescent and affinity tags were employed for exploring this field by labeling the Protein of Interest (POI). However, the autofluorescence and weak binding strength significantly reduce the accuracy and specificity of these tags. Conversely, HaloTag, a novel self-labeling enzyme (SLE) tag, could quickly form a covalent bond with its ligand, enabling fast and specific labeling of POI. These desirable features greatly increase the accuracy and specificity, making the HaloTag a valuable system for various applications ranging from imaging to immobilization of POI. Notably, the HaloTag technique has already been successfully employed in a series of studies with excellent efficiency. In this review, we summarize the development of HaloTag and recent advanced investigations associated with HaloTag, including

Over the past decades, the incidence of thyroid cancer (TC) rapidly increased all over the world, with the papillary thyroid cancer (PTC) accounting for the vast majority of TC cases. It is crucial to investigate novel diagnostic and therapeutic targets for PTC and explore more detailed molecular mechanisms in the carcinogenesis and progression of PTC. Based on the TCGA and GEO databases, FAM111B is downregulated in PTC tissues and predicts better prognosis in PTC patients. FAM111B suppresses the growth, migration, invasion and glycolysis of PTC both

Line segment matching is essential for industrial applications such as scene reconstruction, pattern recognition, and VSLAM. To achieve good performance under the scene with illumination changes, we propose a line segment matching method fusing local gradient order and non-local structure information. This method begins with intensity histogram multiple averaging being utilized for adaptive partitioning. After that, the line support region is divided into several sub-regions, and the whole image is divided into a few intervals. Then the sub-regions are encoded by local gradient order, and the intervals are encoded by non-local structure information of the relationship between the sampled points and the anchor points. Finally, two histograms of the encoded vectors are, respectively, normalized and cascaded. The proposed method was tested on the public datasets and compared with previous methods, which are the line-junction-line (LJL), the mean-standard deviation line descriptor (MSLD) and the line-point invariant (LPI). Experiments show that our approach has better performance than the representative methods in various scenes. Therefore, a tentative conclusion can be drawn that this method is robust and suitable for various illumination changes scenes.

PURPOSE: Without a standard test for pancreatic carcinomas, this highly lethal disease is normally diagnosed at its advanced stage, leading to a low survival rate of patients. Trophoblast cell-surface antigen 2 (Trop-2), a transmembrane glycoprotein, is associated with cell proliferation and highly expressed in most of solid epithelial tumors, including pancreatic cancer. A non-invasive method of imaging Trop-2 would greatly benefit clinical diagnosis and monitoring of pancreatic cancer. In the current study, (89)Zr-labeled anti-Trop-2 antibody (AF650) was recruited for the systemic evaluation of Trop-2 as an immunoPET target for pancreatic cancer imaging. METHODS: AF650 was conjugated with desferrioxamine (DFO) and then radiolabeled with (89)Zr. Trop-2 expression levels were determined in three pancreatic cancer cell lines (BxPC-3, MIA PaCa-2, and AsPC-1) via western blot, flow cytometry, saturation binding assay, and immunofluorescence staining. The targeting capacity of (89)Zr-DFO-AF650 was evaluated in mouse models with subcutaneous xenograft of pancreatic cancers via PET imaging and bio-distribution studies. In addition, a Trop-2-positive orthotopic cancer model was recruited for further validating the targeting specificity of (89)Zr-DFO-AF650. RESULTS: BxPC-3 cells expressed high levels of Trop-2, while AsPC-1 and MIA PaCa-2 cells expressed low levels of Trop-2. Additionally, (89)Zr-DFO-AF650 exhibited high specificity to Trop-2 in BxPC-3 cells (K(d) = 22.34 ± 2.509 nM). In subcutaneous xenograft models, about 28.8 ± 7.63%ID/g tracer accumulated in the BxPC-3 tumors at 120 h post injection, which was much higher than those reaching MIA PaCa-2 (6.76 ± 2.08%ID/g) and AsPC-1 (3.51 ± 0.69%ID/g) tumors (n = 4). More importantly, (89)Zr-DFO-AF650 could efficiently distinguish primary tumors in the orthotopic BxPC-3 cancer model, showing high correlation between PET imaging and bio-distribution and sensitivity. CONCLUSIONS: (89)Zr-DFO-AF650 can be effectively used to detect pancreatic cancer via Trop-2-mediated immunoPET in vivo, clearly revealing the great potential of Trop-2-based non-invasive imaging in pancreatic cancer detection and treatment monitoring.

Piezoelectric bioorganic thin films Piezoelectric materials enable a reversible conversion between mechanical pressure and electric charge and are useful for sensors, actuators, and high-precision motors. Yang et al. developed a method for making high-quality crystalline thin films of piezoelectric γ-glycine crystals that are grown and refined between layers of polyvinyl alcohol (PVA) (see the Perspective by Berger). The PVA layers are essential to promoting the crystallization of the preferred crystal phase with the polar axis oriented perpendicular to the film plan because of hydrogen bonding at the PVA-glycine interface. The thin films show a macroscopic piezoelectric response and high stability in aqueous environments. The films are water soluble and, when suitably packaged, could be implanted into a biodegradable energy-harvesting device. Science , abf2155, this issue p. 337 ; see also abj0424, p. 278

Theranostic nanoparticles hold the potential to greatly improve cancer management by providing personalized medicine. Although many theranostic nanoconstructs have been successful in preclinical studies, clinical translation is still hampered by their limited targeting capability and lack of successful therapeutic efficacy. We report the use of novel ultrasmall porous silica nanoparticles (UPSN) with enhanced in vivo pharmacokinetics such as high target tissue accumulation (12% ID/g in the tumor) and evasion from the reticuloendothelial system (RES) organs. Herein, UPSN is conjugated with the isotopic pair (90/86)Y, enabling both noninvasive imaging as well as internal radiotherapy. In vivo PET imaging demonstrates prolonged blood circulation and excellent tumor contrast with (86)Y-DOTA-UPSN. Tumor-to-muscle and tumor-to-liver uptake values were significantly high (12.4 ± 1.7 and 1.5 ± 0.5, respectively), unprecedented for inorganic nanomaterials. (90)Y-DOTA-UPSN significantly inhibits tumor growth and increases overall survival, indicating the promise of UPSN for future clinical translation as a cancer theranostic agent.

During cerebral ischemia-reperfusion (I-R) injury, the infiltration of monocyte/macrophages (M

Adoptive cell therapy by natural cells for drug delivery has achieved encouraging progress in cancer treatment over small-molecule drugs. Macrophages have a great potential in antitumor drug delivery due to their innate capability of sensing chemotactic cues and homing toward tumors. However, major challenge in current macrophage-based cell therapy is loading macrophages with adequate amounts of therapeutic, while allowing them to play a role in immunity without compromising cell functions. Herein, a potent strategy to construct a macrophage-mediated drug delivery platform loaded with a nanosphere (CpG-ASO-Pt) (CAP) composed of functional nucleic acid therapeutic (CpG-ASO) and chemotherapeutic drug cisplatin (Pt) is demonstrated. These CAP nanosphere loaded macrophages (CAP@M) are employed not only as carriers to deliver this nanosphere toward the tumor sites, but also simultaneously to guide the differentiation and maintain immunostimulatory effects. Both in vitro and in vivo experiments indicate that CAP@M is a promising nanomedicine by macrophage-mediated nanospheres delivery and synergistically immunostimulatory activities. Taken together, this study provides a new strategy to construct a macrophage-based drug delivery system for synergistic chemo-/gene-/immuno-therapy.

In recent years, there have been significant innovations in the development of nanoparticle-based vaccines and vaccine delivery systems. For the purposes of both design and evaluation, these nanovaccines are imaged using the wealth of understanding established around medical imaging of nanomaterials. An important insight to the advancement of the field of nanovaccines can be given by an analysis of the design rationale of an imaging platform, as well as the significance of the information provided by imaging. Nanovaccine imaging strategies can be categorized by the imaging modality leveraged, but it is also worth understanding the superiority or convenience of a given modality over others in a given context of a particular nanovaccine. The most important imaging modalities in this endeavor are optical imaging including near-infrared fluorescence imaging (NIRF), emission tomography methods such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) with or without computed tomography (CT) or magnetic resonance (MR), the emerging magnetic particle imaging (MPI), and finally, multimodal applications of imaging which include molecular imaging with magnetic resonance imaging (MRI) and photoacoustic (PA) imaging. One finds that each of these modalities has strengths and weaknesses, but optical and PET imaging tend, in this context, to be currently the most accessible, convenient, and informative modalities. Nevertheless, an important principle is that there is not a one-size-fits-all solution, and that the specific nanovaccine in question must be compatible with a particular imaging modality. This article is categorized under: Nanotechnology Approaches to BiologyNanoscale Systems in Biology Therapeutic Approaches and Drug DiscoveryNanomedicine for Oncologic Disease Therapeutic Approaches and Drug DiscoveryNanomedicine for Infectious Disease.

Background Nonspecific liver uptake of nanomaterials after intravenous injection has hindered nanomedicine for clinical translation. However, nanomaterials’ propensity for liver distribution might enable their use in hepatic ischemia–reperfusion injury (IRI) repair. During hepatic IRI, reactive oxygen species (ROS) are generated and the fifth component of complement (C5a) is activated. In addition, C5a is confirmed to exacerbate the vicious cycle of oxidative stress and inflammatory damage. For these reasons, we have investigated the development of nanomaterials with liver uptake to scavenge ROS and block C5a for hepatic IRI repair. Results To achieve this goal, a traditional nanoantioxidant of nanoceria was surface conjugated with the anti-C5a aptamers (Ceria@Apt) to scavenge the ROS and reduce C5a-mediated inflammation. High uptake of Ceria@Apt in the liver was confirmed by preclinical positron emission tomography (PET) imaging. The clinical symptoms of hepatic IRI were effectively alleviated by Ceria@Apt with ROS scavenging and C5a blocking in mice model. The released pro-inflammatory cytokines were significantly reduced, and subsequent inflammatory reaction involved in the liver was inhibited. Conclusions The synthesized Ceria@Apt has great potential of medical application in hepatic IRI repair, which could also be applied for other ischemic-related diseases. Graphic abstract

PURPOSE: We dual-labeled an intercellular adhesion molecule-1 (ICAM-1) monoclonal antibody (mAb) and evaluated its effectiveness for lesion detection and surgical navigation in pancreatic ductal adenocarcinoma (PDAC) via multiple noninvasive imaging approaches, including positron emission tomography (PET), near-infrared fluorescence (NIRF), and Cerenkov luminescence imaging (CLI). METHODS: ICAM-1 expression in PDAC cell lines (BxPC-3 and AsPC-1) was assessed via flow cytometry and immunofluorescent staining. An ICAM-1 mAb labeled by IRDye 800CW and radionuclide zirconium-89 (denoted as [(89)Zr]Zr-DFO-ICAM-1-IR800) was synthesized. Its performance was validated via in vivo comparative PET/NIRF/CLI and biodistribution (Bio-D) studies in nude mice bearing subcutaneous BxPC-3/AsPC-1 tumors or orthotopic BxPC-3 tumor models using nonspecific IgG as an isotype control tracer. RESULTS: ICAM-1 expression was strong in the BxPC-3 and minimal in the AsPC-1 cell line. Both multimodality imaging and Bio-D data exhibited more prominent uptake of [(89)Zr]Zr-DFO-ICAM-1-IR800 in BxPC-3 tumors than in AsPC-1 tumors. The uptake of [(89)Zr]Zr-DFO-IgG-IR800 in BxPC-3 tumors was similar to that of [(89)Zr]Zr-DFO-ICAM-1-IR800 in AsPC-1 tumors. These results demonstrate the desirable affinity and specificity of [(89)Zr]Zr-DFO-ICAM-1-IR800 compared to [(89)Zr]Zr-DFO-IgG-IR800. Orthotopic BxPC-3 tumor foci could also be clearly delineated by [(89)Zr]Zr-DFO-ICAM-1-IR800. An intermodal match was achieved in the ICAM-1-targeted immunoPET/NIRF/CLI. The positive expression levels of ICAM-1 in BxPC-3 tumor tissue were further confirmed by immunohistopathology. CONCLUSION: We successfully developed a dual-labeled ICAM-1-targeted tracer for PET/NIRF/CLI of PDAC that can facilitate better diagnosis and intervention of PDAC upon clinical translation.

Ideal nuclear imaging tracers should exhibit high target uptake and low background signal. Traditional renal scintigraphy and SPECT scans examine kidney function via static or dynamic tracing of radioactive probes in the kidneys. The lack of tracer affinity to specific biological processes and high background uptake from urinary excretion have added many difficulties to precision renal diagnosis. In this issue of Theranostics, Jin and colleagues innovatively devised a recombinant probe for preferential kidney imaging through targeting of tubular neonatal Fc receptor and proximal tubular basement membrane for sustained tubular reabsorption and accumulation. This work has broad implications regarding how an in depth understanding of physiology and pathology may be of service for tracer development, renal diagnosis, and disease theranostics.

Single-domain antibody (sdAb) is among the most promising vectors for developing molecular imaging tracers. Several sdAb tracers targeting human epidermal growth factor receptor 2 or programmed death ligand 1 have entered clinical practice. However, radiolabeled single-valent sdAbs generally have high kidney retention, limiting their therapeutic applications. Therefore, engineering strategies such as PEGylation or incorporation of renal cleavable linkers can be adapted to improve pharmacokinetics and reduce kidney retention. In this Focus on Molecular Imaging review, we try to summarize the latest developments in sdAb-derived agents and propose potential strategies that can be used to improve the theranostic value of radiolabeled sdAbs.

Deleterious effects to normal tissues and short biological half-life of sonosensitizers limit the applications of sonodynamic therapy (SDT). Herein we synthesize a new sonosensitizer (Cu(II)NS) that consists of porphyrins, the chelated Cu(2+), and PEG to overcome the challenges of SDT. As Cu(2+) contains 27 electrons, Cu(II)NS have an unpaired electron (open shell), resulting in a doublet ground state and little sonosensitivity. Overexpressed glutathione (GSH) in the tumor can reduce Cu(2+) to generate Cu(I)NS, leading to a singlet ground state and recuperative sonosensitivity. Additionally, PEG endows Cu(II)NS with increased blood biological half-life and enhanced tumor accumulation, further increasing the effect of SDT. Through regulating the valence state of Cu, we achieve cancer SDT with enhanced therapeutic index.

Hepatic ischemia-reperfusion injury (IRI), which mainly results from excessive reactive oxygen species (ROS) generated by a reperfusion burst of oxygen, has long been a major cause of liver dysfunction and failure after surgical procedures. Here, a monodispersed hydrophilic carbohydrate-derived nanoparticle (C-NP) was synthesized as a nanoantioxidant that could effectively prevent hepatic IRI. The spherical C-NPs had a size of ∼78 ± 11.3 nm covered with polar surface groups. They were well dispersible in water with good colloidal stability, nontoxicity, and good ROS scavenging capability. The C-NPs also exhibited good circulation lifetime, effective delivery to liver, and gradual degradability with an ability to assist the IRI group maintaining a normal and healthy liver status. The pathology mechanism of C-NPs in hepatic IRI was confirmed to be scavenging of excessive ROS by C-NPs. The effective therapeutic treatment of C-NPs in living animals revealed a great potential in clinical prevention for hepatic IRI.

Nanomedicine has benefited from recent advances in chemistry and biomedical engineering to produce nanoscale materials as theranostic agents. Well-designed nanomaterials may present optimal biological properties, influencing circulation, retention, and excretion for imaging and treatment of various diseases. As the understanding of nanomedicine pharmacokinetics expands continuously, efficient renal clearance of nanomedicines can significantly increase the signal-to-background ratio for precision diagnosis and lower potential toxicity for improved treatment. Studies on nanomaterial-kidney interactions have led to many novel findings on the underlying principles of nanomaterial renal clearance, targeting, and accumulation. In return, the optimized nanomedicines confer significant benefits to the detection and treatment of kidney dysfunction.In this Account, we present an overview of recent progress in the development of nanomaterials for kidney theranostics, aiming to speed up translation and expand possible applications. We start by introducing biological structures of the kidney and their influence on renal targeting, retention, and clearance. Several key factors regarding renal accumulation and excretion, including nanomaterial types, sizes, and shapes, surface charges, and chemical modifications, are identified and discussed. Next, we highlight our recent efforts investigating kidney-interacting nanomaterials and introduce representative nanomedicines for imaging and treatment of kidney diseases. Multiple renal-clearable and renal-accumulating nanomedicines were devised for kidney function imaging. By employing renal-clearable nanomedicines, including gold nanoparticles, porphyrin polymers, DNA frameworks, and polyoxometalate clusters, we were able to noninvasively evaluate split renal function in healthy and diseased mice. Further engineering of renal-accumulating nanosystems has shifted attention from renal diagnosis to precision kidney protection. Many biocompatible nanomedicines, such as DNA origami, selenium-doped carbon quantum dots, melanin nanoparticles, and black phosphorus have all played essential roles in diminishing excessive reactive oxygen species for kidney treatment and protection. Finally, we discuss the challenges and perspectives of nanomaterials for renal care, their future clinical translation, and how they may affect the current landscape of clinical practices. We believe that this Account updates our current understanding of nanomaterial-kidney interactions for further design and control of nanomedicines for specific kidney diagnosis and treatment. This timely Account will generate broad interest in integrating nanotechnology and nanomaterial-biological interaction for state-of-the-art theranostics of renal diseases.

PURPOSE: Intercellular adhesion molecule-1 (ICAM-1, CD54) is an emerging therapeutic target for a variety of solid tumors including melanoma and anaplastic thyroid cancer (ATC). This study aims to develop an ICAM-1-targeted immuno-positron emission tomography (immunoPET) imaging strategy and assess its diagnostic value in melanoma and ATC models. METHODS: Flow cytometry was used to screen ICAM-1-positive melanoma and ATC cell lines. Melanoma and ATC models were established using A375 cell line and THJ-16T cell line, respectively. An ICAM-1-specific monoclonal antibody (R6–5-D6) and a nonspecific human IgG were radiolabeled with (64)Cu and the diagnostic efficacies were interrogated in tumor-bearing mouse models. Biodistribution and fluorescent imaging studies were performed to confirm the specificity of the ICAM-1-targeted imaging probes. RESULTS: ICAM-1 was strongly expressed on melanoma and advanced thyroid cancer cell lines. (64)Cu-NOTA-ICAM-1 immunoPET imaging efficiently delineated A375 melanomas with a peak tumor uptake of 21.28 ± 6.56 %ID/g (n = 5), significantly higher than that of (64)Cu-NOTA-IgG (10.63 ± 2.58 %ID/g, n = 3). Moreover, immunoPET imaging with (64)Cu-NOTA-ICAM-1 efficiently visualized subcutaneous and orthotopic ATCs with high clarity and contrast. Fluorescent imaging with IRDye 800CW-ICAM-1 also visualized orthotopic ATCs and the tumor uptake could be blocked by the ICAM-1 parental antibody R6–5-D6, indicating the high specificity of the developed probe. Finally, blocking with the human IgG prolonged the circulation of the (64)Cu-NOTA-ICAM-1 in R2G2 mice without compromising the tumor uptake. CONCLUSION: ICAM-1-targeted immunoPET imaging could characterize ICAM-1 expression in melanoma and ATC, which holds promise for optimizing ICAM-1-targeted therapies in the future.

Pancreatic cancer is highly aggressive, with a median survival time of less than 6 months and a 5-year overall survival rate of around 7%. The poor prognosis of PaCa is largely due to its advanced stage at diagnosis and the lack of efficient therapeutic options. Thus, the development of an efficient, multifunctional PaCa theranostic system is urgently needed. Overexpression of tissue factor (TF) has been associated with increased tumor growth, angiogenesis, and metastasis in many malignancies, including pancreatic cancer. Herein, we propose the use of a TF-targeted monoclonal antibody (ALT836) conjugated with the pair (86/90)Y as atheranostic agent against pancreatic cancer. For methods, serial PET imaging with (86)Y-DTPA-ALT836 was conducted to map the biodistribution the tracer in BXPC-3 tumor-bearing mice. (90)Y-DTPA-ALT836 was employed as a therapeutic agent that also allowed tumor burden monitoring through Cherenkov luminescence imaging. The results were that the uptake of (86)Y-DTPA-ALT836 in BXPC-3 xenograft tumors was high and increased over time up to 48 h postinjection (p.i.), corroborated through ex vivo biodistribution studies and further confirmed by Cherenkov luminescence Imaging. In therapeutic studies, (90)Y-DTPA-ALT836 was found to slow tumor growth relative to the control groups and had significantly smaller (p < 0.05) tumor volumes 1 day p.i. Histological analysis of ex vivo tissues revealed significant damage to the treated tumors. The conclusion is that the use of the (86/90)Y theranostic pair allows PET imaging with excellent tumor-to-background contrast and treatment of TF-expressing pancreatic tumors with promising therapeutic outcomes.

Nanocarriers are employed to deliver photosensitizers for photodynamic therapy (PDT) through the enhanced penetration and retention effect, but disadvantages including the premature leakage and non-selective release of photosensitizers still exist. Herein, we report a 1 O2 -responsive block copolymer (POEGMA-b-P(MAA-co-VSPpaMA) to enhance PDT via the controllable release of photosensitizers. Once nanoparticles formed by the block copolymer have accumulated in a tumor and have been taken up by cancer cells, pyropheophorbide a (Ppa) could be controllably released by singlet oxygen (1 O2 ) generated by light irradiation, enhancing the photosensitization. This was demonstrated by confocal laser scanning microscopy and in vivo fluorescence imaging. The 1 O2 -responsiveness of POEGMA-b-P(MAA-co-VSPpaMA) block copolymer enabled the realization of self-amplified photodynamic therapy by the regulation of Ppa release using NIR illumination. This may provide a new insight into the design of precise PDT.

The chirality of nanoparticles directly influences their transport and biological effect under physiological environment, but the details of this phenomenon have rarely been explored. Herein, chiral GSH-anchored selenium nanoparticles (G@SeNPs) are fabricated to investigate the interaction between their chirality and transport and antioxidant activity. G@SeNPs modified with different enantiomers show opposite handedness with a tunable circular dichroism signal. The noninvasive positron emission tomography imaging clearly reveals that (64)Cu-labeled (L)-G@SeNPs experience distinctly different transport among the major organs from their (D)-and (DL)-counterparts, demonstrating that the chirality of the G@SeNPs influences the biodistribution and kinetics. Taking advantage of the strong homologous cell adhesion and uptake, (L)-G@SeNPs have been shown here to effectively prevent oxidation damage caused by palmitic acid in insulinoma cells. This work should motivate the biomedical applications of chiral nanomedicine by providing a fundamental understanding of chirality-dependent biodistribution and antioxidant activity.

Fibroblast activation protein (FAP) is a type II membrane-bound glycoprotein which is overexpressed in cancer-associated fibroblasts and activated fibroblasts at wound healing/inflammatory sites. Since the first clinical application of quinoline-based FAP ligands in 2018, FAP inhibitor (FAPI)-based PET imaging and radiotherapy have been investigated for a wide variety of diseases, both cancerous and non-cancerous. As a consequence, promising strides have been made in particular to improve the understanding of FAPI-based PET imaging and the potential value of FAPI-based tumor radiotherapy. Herein, we present a comprehensive review of radiolabeled FAPI, including their clinical translation, in order to clarify the current and potential future role of this class of molecules in nuclear medicine. In particular, this review underlines the value of FAPI radiopharmaceuticals in the diagnosis or therapy of tumors or benign conditions. However, limitations in present studies have hampered a precise evaluation of FAPI radiopharmaceuticals. Despite this, it will likely be worthwhile to further explore the clinical value of FAPI in diagnosis and therapy through better-designed and larger-population clinical trials in the future.

Acute kidney injury (AKI) leads to unacceptably high mortality due to difficulties in timely intervention and less efficient renal delivery of therapeutic drugs. Here, a series of polyvinylpyrrolidone (PVP)-curcumin nanoparticles (PCurNP) are designed to meet the renal excretion threshold (∼45 kDa), presenting a controllable delivery nanosystem for kidney targeting. Renal accumulation of the relatively small nanoparticles