Modulating Ionic Transport and Interface Chemistry via Surface-Modified Silica Carrier in Nano Colloid Electrolyte for Stable Cycling of Li-Metal Batteries.

Tailoring the Li+ microenvironment is crucial for achieving fast ionic transfer and a mechanically reinforced solid-electrolyte interphase (SEI), which administers the stable cycling of Li-metal batteries (LMBs). Apart from traditional salt/solvent compositional tuning, this study presents the simultaneous modulation of Li+ transport and SEI chemistry using a citric acid (CA)-modified silica-based colloidal electrolyte (C-SCE). CA-tethered silica (CA-SiO2 ) can render more active sites for attracting complex anions, leading to further dissociation of Li+ from the anions, resulting in a high Li+ transference number (≈0.75). Intermolecular hydrogen bonds between solvent molecules and CA-SiO2 and their migration also act as nano-carrier for delivering additives and anions toward the Li surface, reinforcing the SEI via the co-implantation of SiO2 and fluorinated components. Notably, C-SCE demonstrated Li dendrite suppression and improved cycling stability of LMBs compared with the CA-free SiO2 colloidal electrolyte, hinting that the surface properties of the nanoparticles have a huge impact on the dendrite-inhibiting role of nano colloidal electrolytes.

Accelerating the Biodegradation of High-Density Polyethylene (HDPE) Using Bjerkandera adusta TBB-03 and Lignocellulose Substrates.

High-density polyethylene (HDPE) is a widely used organic polymer and an emerging pollutant, because it is very stable and nonbiodegradable. Several fungal species that produce delignifying enzymes are known to be promising degraders of recalcitrant polymers, but research on the decomposition of plastics is scarce. In this study, white rot fungus, Bjerkandera adusta TBB-03, was isolated and characterized for its ability to degrade HDPE under lignocellulose substrate treatment. Ash (Fraxinus rhynchophylla) wood chips were found to stimulate laccase production (activity was > 210 U/L after 10 days of cultivation), and subsequently used for HDPE degradation assay. After 90 days, cracks formed on the surface of HDPE samples treated with TBB-03 and ash wood chips in both liquid and solid states. Raman analysis showed that the amorphous structure of HDPE was degraded by enzymes produced by TBB-03. Overall, TBB-03 is a promising resource for the biodegradation of HDPE, and this work sheds light on further applications for fungus-based plastic degradation systems.

Efficient harvesting of wet blue-green microalgal biomass by two-aminoclay [AC]-mixture systems.

Blue-green microalgal blooms have been caused concerns about environmental problems and human-health dangers. For removal of such cyanobacteria, many mechanical and chemical treatments have been trialled. Among various technologies, the flocculation-based harvesting (precipitation) method can be an alternative if the problem of the low yield of recovered biomass at low concentrations of cyanobacteria is solved. In the present study, it was utilized mixtures of magnesium aminoclay [MgAC] and cerium aminoclay [CeAC] with different particle sizes to harvest cyanobacteria feedstocks with ∼100% efficiency within 1h by ten-fold lower loading of ACs compared with single treatments of [MgAC] or [CeAC]. This success was owed to the compact networks of the different-sized-ACs mixture for efficient bridging between microalgal cells. In order to determine the usage potential of biomass harvested with AC, the mass was heat treated under the reduction condition. This system is expected to be profitably utilizable in adsorbents and catalysts.

Synthesis and comparative biological evaluation of bifunctional ligands for radiotherapy applications of (90)Y and (177)Lu.

Zevalin® is an antibody-drug conjugate radiolabeled with a cytotoxic radioisotope ((90)Y) that was approved for radioimmunotherapy (RIT) of B-cell non-Hodgkin's lymphoma. A bifunctional ligand that displays favorable complexation kinetics and in vivo stability is required for effective RIT. New bifunctional ligands 3p-C-DE4TA and 3p-C-NE3TA for potential use in RIT were efficiently prepared by the synthetic route based on regiospecific ring opening of aziridinium ions with prealkylated triaza- or tetraaza-backboned macrocycles. The new bifunctional ligands 3p-C-DE4TA and 3p-C-NE3TA along with the known bimodal ligands 3p-C-NETA and 3p-C-DEPA were comparatively evaluated for potential use in targeted radiotherapy using ß-emitting radionuclides (90)Y and (177)Lu. The bifunctional ligands were evaluated for radiolabeling kinetics with (90)Y and (177)Lu, and the corresponding (90)Y or (177)Lu-radiolabeled complexes were studied for in vitro stability in human serum and in vivo biodistribution in mice. The results of the comparative complexation kinetic and stability studies indicate that size of macrocyclic cavity, ligand denticity, and bimodality of donor groups have a substantial impact on complexation of the bifunctional ligands with the radiolanthanides. The new promising bifunctional chelates in the DE4TA and NE3TA series were rapid in binding (90)Y and (177)Lu, and the corresponding (90)Y- and (177)Lu-radiolabeled complexes remained inert in human serum or in mice. The in vitro and in vivo data show that 3p-C-DE4TA and 3p-C-NE3TA are promising bifunctional ligands for targeted radiotherapy applications of (90)Y and (177)Lu.

Application of aziridinium ring opening for preparation of optically active diamine and triamine analogues: Highly efficient synthesis and evaluation of DTPA-based MRI contrast enhancement agents.

Ring opening of aziridinium ions with nitrogen nucleophiles was applied to the highly efficient synthesis of optically active vicinal diamines and diethylene triamine pentaacetic acid (DTPA) analogues as potential magnetic resonance imaging (MRI) contrast enhancement agents. The synthetic method features a column-free isolation of the regiospecific and stereospecific nucleophilic substitution products of enantiomerically enriched aziridinium ions in excellent yield.

Preclinical evaluation of NETA-based bifunctional ligand for radioimmunotherapy applications using 212Bi and 213Bi: radiolabeling, serum stability, and biodistribution and tumor uptake studies.

INTRODUCTION: Despite the great potential of targeted α-radioimmunotherapy (RIT) as demonstrated by pre-clinical and clinical trials, limited progress has been made on the improvement of chelation chemistry for (212)Bi and (213)Bi. A new bifunctional ligand 3p-C-NETA was evaluated for targeted α RIT using (212)Bi and (213)Bi. METHODS: Radiolabeling of 3p-C-NETA with (205/6)Bi, a surrogate of (212)Bi and (213)Bi, was evaluated at pH5.5 and room temperature. In vitro stability of the (205/6)Bi-3p-C-NETA-trastuzumab conjugate was evaluated using human serum (pH7, 37 °C). Immunoreactivity and specific activity of the (205/6)Bi-3p-C-NETA-trastuzumab conjugate were measured. An in vivo biodistribution study was performed to evaluate the in vivo stability and tumor targeting properties of the (205/6)Bi-3p-C-NETA-trastuzumab conjugate in athymic mice bearing subcutaneous LS174T tumor xenografts. RESULT: The 3p-C-NETA-trastuzumab conjugate was extremely rapid in complexing with (205/6)Bi, and the corresponding (205/6)Bi-3p-C-NETA-trastuzumab was stable in human serum. (205/6)Bi-3p-C-NETA-trastuzumab was prepared with a high specific activity and retained immunoreactivity. (205/6)Bi-3p-C-NETA-trastuzumab conjugate displayed excellent in vivo stability and targeting as evidenced by low normal organ and high tumor uptake. CONCLUSION: The results of the in vitro and in vivo studies indicate that 3p-C-NETA is a promising chelator for RIT applications using (212)Bi and (213)Bi. Further detailed in vivo evaluations of 3p-C-NETA for targeted α RIT are warranted.

Synthesis and preclinical evaluation of bifunctional ligands for improved chelation chemistry of 90Y and 177Lu for targeted radioimmunotherapy.

We report a practical and high-yield synthesis of a bimodal bifunctional ligand 3p-C-NETA-NCS containing the isothiocyanate group for conjugation to a tumor targeting antibody. 3p-C-NETA-NCS was conjugated to a tumor-targeting antibody, trastuzumab, and the corresponding 3p-C-NETA-trastuzumab conjugate was evaluated and compared to trastuzumab conjugates of the known bifunctional ligands C-DOTA, C-DTPA, and 3p-C-DEPA for radiolabeling kinetics with (90)Y and (177)Lu. 3p-C-NETA-trastuzumab conjugate exhibited extremely rapid complexation kinetics with (90)Y and (177)Lu. (90)Y-3p-C-NETA-trastuzumab and (177)Lu-3p-C-NETA-trastuzumab conjugates were stable in human serum for 2 weeks. A pilot biodistribution study was conducted to evaluate in vivo stability and tumor targeting of (177)Lu-radiolabeled trastuzumab conjugate using nude mice bearing ZR-75-1 human breast cancer. (177)Lu-3p-C-NETA-trastuzumab conjugate displayed low radioactivity level at blood (1.6%), low organ uptake (<2.2%), and high tumor-to-blood ratio (6.4) at 120 h. 3p-C-NETA possesses favorable in vitro and in vivo profiles and is an excellent bifunctional chelator that can be used for targeted RIT applications using (90)Y and (177)Lu and has the potential to replace DOTA and DTPA analogues in current clinical use.

Synthesis and evaluation of a bifunctional chelate for development of Bi(III)-labeled radioimmunoconjugates.

A new bifunctional ligand C-DEPA was designed and synthesized as a component for antibody-targeted radiation therapy (radioimmunotherapy, RIT) of cancer. C-DEPA was conjugated to a tumor targeting antibody, trastuzumab, and the corresponding C-DEPA-trastuzumab conjugate was evaluated for radiolabeling kinetics with (205/6)Bi. C-DEPA-trastuzumab conjugate rapidly bound (205/6)Bi, and (205/6)Bi-C-DEPA-trastuzumab conjugate was stable in human serum for 72 h. The in vitro radiolabeling kinetics and serum stability data suggest that C-DEPA is a potential chelate for preclinical RIT applications using (212)Bi and (213)Bi.

Efficient bifunctional decadentate ligand 3p-C-DEPA for targeted α-radioimmunotherapy applications.

A new bifunctional ligand 3p-C-DEPA was synthesized and evaluated for use in targeted α-radioimmunotherapy. 3p-C-DEPA was efficiently prepared via regiospecific ring opening of an aziridinium ion and conjugated with trastuzumab. The 3p-C-DEPA-trastuzumab conjugate was extremely rapid in binding (205/6)Bi, and the corresponding (205/6)Bi-3p-C-DEPA-trastuzumab complex was stable in human serum. Biodistribution studies were performed to evaluate in vivo stability and tumor targeting of (205/6)Bi-3p-C-DEPA-trastuzumab conjugate in tumor bearing athymic mice. (205/6)Bi-3p-C-DEPA-trastuzumab conjugate displayed excellent in vivo stability and targeting as evidenced by low organ uptake and high tumor uptake. The results of the in vitro and in vivo studies indicate that 3p-C-DEPA is a promising chelator for radioimmunotherapy of (212)Bi and (213)Bi.

A highly effective bifunctional ligand for radioimmunotherapy applications.

A novel bifunctional ligand (3p-C-NETA) for antibody-targeted radioimmunotherapy (RIT) of ß-emitting radioisotopes (90)Y and (177)Lu was efficiently synthesized via an unexpected regiospecific ring opening of an aziridinium ion. 3p-C-NETA instantly formed a very stable complex with (90)Y or (177)Lu. 3p-C-NETA is an excellent bifunctional ligand for RIT.

Efficient synthesis of functionalized aziridinium salts.

Various aziridinium salts were efficiently prepared from bromination of a series of backbone substituted N,N-bisubstituted beta-amino alcohols and isolated via flash column chromatography. The effect of C-substitution, N-substitution, solvent, leaving group, and counteranions on formation of the isolable aziridinium salts was investigated.

Bile acid-based polyaminocarboxylate conjugates as targeted antitumor agents.

Bile acid-polyaminocarboxylate conjugates containing NE3TA, a potential iron chelator displayed significant cytotoxicities in both HeLa and HT29 colon cancer cells, and cholic acid-NE3TA attached to an organic fluorophore was shown to enter the HT29 cancer cells.

Stable aziridinium salts as versatile intermediates: isolation and regio- and stereoselective ring-opening and rearrangement.

Rock trapping and exploration: Aziridinium bromide salts were discovered serendipitously during bromination of N,N-dicarboxymethylated beta-amino alcohols. Regiospecific ring-opening and rearrangement of the isolated, surprisingly stable aziridinium salts produces useful molecules including C-functionalized oxomorpholines and alpha,beta-unsaturated amines.

Synthesis and biological evaluation of a novel decadentate ligand DEPA.

An efficient and short synthetic route to a novel decadentate ligand 7-[2-(bis-carboxymethyl-amino)-ethyl]-4,10-bis-carboxymethyl-1,4,7,10-tetraaza-cyclododec-1-yl-acetic acid (DEPA) with both macrocyclic and acyclic binding moieties is reported. A reproducible and scalable synthetic method to a precursor molecule of DEPA, 1,4,7-tris(tert-butoxycarbonylmethyl)tetraazacyclododecane was developed. DEPA was evaluated as a chelator of (177)Lu, (212)Bi, and (213)Bi for potential use in an antibody-targeted cancer therapy, radioimmunotherapy (RIT) using Arsenazo III based spectroscopic complexation kinetics, in vitro serum stability, and in vivo biodistribution studies.

Novel bimodal bifunctional ligands for radioimmunotherapy and targeted MRI.

The structurally novel bifunctional ligands C-NETA and C-NE3TA, each possessing both acyclic and macrocyclic moieties, were prepared and evaluated as potential chelates for radioimmunotherapy (RIT) and targeted magnetic resonance imaging (MRI). Heptadentate C-NE3TA was fortuitously discovered during the preparation of C-NETA. An optimized synthetic method to C-NETA and C-NE3TA including purification of the polar and tailing reaction intermediates, tert-butyl C-NETA (2) and tert-butyl C-NE3TA (3) using semiprep HPLC was developed. The new Gd(III) complexes of C-NETA and C-NE3TA were prepared as contrast enhancement agents for use in targeted MRI. The T 1 relaxivity data indicate that Gd(C-NETA) and Gd(C-NE3TA) possess higher relaxivity than Gd(C-DOTA), a bifunctional version of a commercially available MRI contrast agent; Gd(DOTA). C-NETA and C-NE3TA were radiolabeled with (177)Lu, (90)Y, (203)Pb, (205/6)Bi, and (153)Gd; and in vitro stability of the radiolabeled corresponding complexes was assessed in human serum. The in vitro studies indicate that the evaluated radiolabeled complexes were stable in serum for 11 days with the exception being the (203)Pb complexes of C-NETA and C-NE3TA, which dissociated in serum. C-NETA and C-NE3TA radiolabeled (177)Lu, (90)Y, or (153)Gd complexes were further evaluated for in vivo stability in athymic mice and possess excellent or acceptable in vivo biodistribution profile. (205/6)Bi- C-NE3TA exhibited extremely rapid blood clearance and low radioactivity level at the normal organs, while (205/6)Bi- C-NETA displayed low radioactivity level in the blood and all of the organs except for the kidney where relatively high renal uptake of radioactivity is observed. C-NETA and C-NE3TA were further modified for conjugation to the monoclonal antibody Trastuzumab.

Efficient synthesis and evaluation of bimodal ligand NETA.

The efficient and short synthetic route to the structurally novel bimodal ligand NETA for antibody-targeted radiation therapy (radioimmunotherapy, RIT) of cancer was developed. The structure of NETA was determined by X-ray crystallography. The arsenazo-based UV spectroscopic complexation kinetics data suggest that NETA is a promising chelator for use in RIT applications of (212)Bi, (213)Bi, and (177)Lu.

A novel cholic acid-based contrast enhancement agent for targeted MRI.

The novel Gd(III) complexes of heptadentate ligands NE3TA and NE3TA-Bn were prepared, and their relaxivities were measured and favorably compared to the commercially available MRI contrast enhancement agent Gd(DOTA). NE3TA was conjugated with cholic acid (CA) to produce CA-NE3TA. TEM images of Gd(CA-NE3TA) indicate that the complex self-assembles forming nano-sized micelles and displays an over threefold increased relaxivity compared to Gd(DOTA). The new cholic acid-conjugated nanoparticle MR contrast enhancement agent, Gd(CA-NE3TA) possesses great promise for use in targeted MRI.

Synthesis and evaluation of novel polyaminocarboxylate-based antitumor agents.

Iron depletion, using iron chelators targeting transferrin receptor (TfR) and ribonucleotide reductase (RR), is proven to be effective in the treatment of cancer. We synthesized and evaluated novel polyaminocarboxylate-based chelators NETA, NE3TA, and NE3TA-Bn and their bifunctional versions C-NETA, C-NE3TA, and N-NE3TA for use in iron depletion tumor therapy. The cytotoxic activities of the novel polyaminocarboxylates were evaluated in the HeLa and HT29 colon cancer cell lines and compared to the clinically available iron depletion agent DFO and the frequently explored polyaminocarboxylate DTPA. All new chelators except C-NETA displayed enhanced cytotoxicities in both HeLa and HT29 cancer cells compared to DFO and DTPA. Incorporation of the nitro functional unit for conjugation to a targeting moiety into the two potent non-functionalized chelators NE3TA and NE3TA-Bn (C-NE3TA and N-NE3TA) was well-tolerated and resulted in a minimal decrease in cytotoxicity. Cellular uptake of C-NE3TA, examined using a confocal microscope, indicates that the chelator is taken up into HT29 cancer cells.

Rational design and generation of a bimodal bifunctional ligand for antibody-targeted radiation cancer therapy.

An antibody-targeted radiation therapy (radioimmunotherapy, RIT) employs a bifunctional ligand that can effectively hold a cytotoxic metal with clinically acceptable complexation kinetics and stability while being attached to a tumor-specific antibody. Clinical exploration of the therapeutic potential of RIT has been challenged by the absence of adequate ligand, a critical component for enhancing the efficacy of the cancer therapy. To address this deficiency, the bifunctional ligand C-NETA in a unique structural class possessing both a macrocyclic cavity and a flexible acyclic moiety was designed. The practical, reproducible, and readily scalable synthetic route to C-NETA was developed, and its potential as the chelator of (212)Bi, (213)Bi, and (177)Lu for RIT was evaluated in vitro and in vivo. C-NETA rapidly binds both Lu(III) and Bi(III), and the respective metal complexes remain extremely stable in serum for 14 days. (177)Lu -C-NETA and (205/6)Bi -C-NETA possess an excellent or acceptable in vivo biodistribution profile.

Novel synthetic ligands for targeted PET imaging and radiotherapy of copper.

Novel ligands, NBEA, NBPA, NETA, NE3TA, and NE3TA-Bn, were synthesized and evaluated as potential chelators of copper radioisotopes for use in targeted positron emission tomography (PET) imaging or radiation therapy. The new ligands were radiolabeled with (64)Cu, and in vitro stability of the radiolabeled complexes was assessed in rat serum. Serum stability results suggest that among the ligands tested, NETA, NE3TA, and NE3TA-Bn form stable complexes with (64)Cu.