Remediation of Metal Oxide Nanotoxicity with a Functional Amyloid.

Understanding the environmental health and safety of nanomaterials (NanoEHS) is essential for the sustained development of nanotechnology. Although extensive research over the past two decades has elucidated the phenomena, mechanisms, and implications of nanomaterials in cellular and organismal models, the active remediation of the adverse biological and environmental effects of nanomaterials remains largely unexplored. Inspired by recent developments in functional amyloids for biomedical and environmental engineering, this work shows their new utility as metallothionein mimics in the strategically important area of NanoEHS. Specifically, metal ions released from CuO and ZnO nanoparticles are sequestered through cysteine coordination and electrostatic interactions with beta-lactoglobulin (bLg) amyloid, as revealed by inductively coupled plasma mass spectrometry and molecular dynamics simulations. The toxicity of the metal oxide nanoparticles is subsequently mitigated by functional amyloids, as validated by cell viability and apoptosis assays in vitro and murine survival and biomarker assays in vivo. As bLg amyloid fibrils can be readily produced from whey in large quantities at a low cost, the study offers a crucial strategy for remediating the biological and environmental footprints of transition metal oxide nanomaterials.

Exploring Peptido-Nanocomposites in the Context of Amyloid Diseases.

Therapeutic peptides are a major class of pharmaceutical drugs owing to their target-binding specificity as well as their versatility in inhibiting aberrant protein-protein interactions associated with human pathologies. Within the realm of amyloid diseases, the use of peptides and peptidomimetics tailor-designed to overcome amyloidogenesis has been an active research endeavor since the late 90s. In more recent years, incorporating nanoparticles for enhancing the biocirculation and delivery of peptide drugs has emerged as a frontier in nanomedicine, and nanoparticles have further demonstrated a potency against amyloid aggregation and cellular inflammation to rival strategies employing small molecules, peptides, and antibodies. Despite these efforts, however, a fundamental understanding of the chemistry, characteristics and function of peptido-nanocomposites is lacking, and a systematic analysis of such strategy for combating a range of amyloid pathogeneses is missing. Here we review the history, principles and evolving chemistry of constructing peptido-nanocomposites from bottom up and discuss their future application against amyloid diseases that debilitate a significant portion of the global population.

A theoretical study of laser-induced ultrafast spin dynamics in trigonal monopyramidal iron and nickel complexes.

We present a first-principles study of the geometries, electronic structures, and laser-induced ultrafast spin dynamics in four trigonal monopyramidal complexes [tpat-BuFe]-, [tcmat-BuFe]-, [tpat-BuNi]-, and [tcmat-BuNi]- [tpa: tris-(pyrrolylmethyl)amine; tcma: tris(carbamoyl-methyl)amine; t-Bu: tert-butyl]. It is found that the low-lying level distribution of the four structures is similar, however, their spin and charge localization differs substantially. Detailed analysis demonstrates that the iron complexes have much more singly spin localized states located in the low energy region, while the nickel complexes have more charge-transfer (CT) states and more states with spin equally distributed between the Ni and the ligands. Affected by these features, more ultrafast spin-crossover (SCO) scenarios are achieved in the two iron complexes, and better CT dynamics is obtained in nickel complexes. In particular, for the CT scenarios combined with spin bifurcation, the charge is transferred from the tpa/tcma ligand to the Fe/Ni atoms, while spin-density transfer occurs in the opposite direction. Among the scenarios illustrated in the paper, the SCO processes turn out to be more complicated since they involve many more intermediate states and exhibit relatively low fidelity. In addition, the transferability of each scenario is analyzed from the absorption spectra of the initial and final states. All these results can provide significant insights into the electronic and magnetic natures of the four complexes, guide the experimental realization of the relevant scenarios, and thus promote their applications in molecular spintronics.

Simultaneous quantification of cefuroxime and clindamycin in human lumbar anulus fibrosus, nucleus pulposus and serum via UPLC-MS/MS.

BACKGROUND: This study aimed to develop a sensitive, accurate method for simultaneously quantifying cefuroxime and clindamycin in human serum, lumbar anulus fibrosus and nucleus pulposus. METHODS: Cefuroxime and clindamycin were quantified using ultra high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple-reaction-monitoring mode on a triple-quadrupole AB Qtrap 5500 system in positive ion mode. Internal standards were D3-cefuroxime and D3,13C-clindamycin. Samples were pretreated by precipitating total protein. RESULTS: The method showed high sensitivity and good linearity over broad calibration ranges from 100 to 100 000 ng/mL for cefuroxime and 10 to 10 000 ng/mL for clindamycin in serum, and from 10 to 10 000 ng/mL for cefuroxime and 1 to 1 000 ng/mL for clindamycin in lumbar nucleus pulposus. In all sample types, correlation coefficients were greater than 0.99, intra- and inter-day precision (relative standard deviation) was less than 15%, and accuracy (relative error) was within 14% for both analytes. This method was effective at quantifying penetration of cefuroxime and clindamycin in patients undergoing oblique lumbar interbody fusion surgery. CONCLUSIONS: A very sensitive, specific method for simultaneous detection of cefuroxime and clindamycin has been developed for human lumbar anulus fibrosus, nucleus pulposus and serum samples.

Single-dose escalation study of yogliptin in healthy Chinese volunteers.

BACKGROUND: Yogliptin is a novel xanthine dipeptidyl peptidase-4 (DPP-4) inhibitor targeting type 2 diabetes. After promising preclinical pharmacological studies, the first human trial of yogliptin was designed. METHODS: A randomized, double-blind, parallel, placebo-controlled phase I single-dose escalation study was designed to evaluate the pharmacokinetics, pharmacodynamics, and tolerability after single oral doses of yogliptin in healthy Chinese subjects. Healthy subjects were assigned to nine cohorts, which received a single dose of yogliptin at 2.5, 5, 10, 25, 50, 100, 200, 400, or 600 mg. Two subjects in each cohort received placebo. Blood samples were collected before dosing and up to 192 h afterwards. Urine samples were collected until 120 h after dosing. Plasma and urine drug concentrations were determined using liquid chromatography coupled with tandem mass spectrometry, and DPP-4 activity was measured using a semi-quantitative, fluorescence-based kinetic assay. RESULTS: A total of 104 subjects were enrolled, 103 of whom completed the study (mean age, 25.3 years; mean weight, 58.8 kg; mean BMI, 21.8 kg/m2). A total of 27 adverse events (AEs) occurred in 25 of 86 yogliptin subjects (29.1%), and 3 AEs occurred in 3 of 18 placebo subjects (16.7%). Yogliptin was absorbed with a median time of maximum observed concentration (Tmax) of 3.0 h and was eliminated slowly with a t1/2 of 25.45-43.84 h. The maximum observed concentration (Cmax) and area under the curve (AUC) varied slightly more than dose-proportionally over the dose range from 2.5 to 400 mg. The fraction of drug excreted in urine ranged from 8.39% to 24.77%. Mean DPP-4 inhibition at 24 h after dosing ranged from 97.7% to 99.5%, and DPP-4 inhibition was >80% for 72 h at doses from 25 to 400 mg. DPP-4 inhibition was >80% for 1 week in the group receiving 400 mg. CONCLUSION: Yogliptin was well tolerated in healthy subjects, with no dose-limiting toxicity observed in the range from 2.5 to 600 mg. Yogliptin inhibited plasma DPP-4 activity for 72 h at single doses of 25-200 mg and for 1 week at 400 mg, suggesting that once-weekly dosing of yogliptin is possible in type 2 diabetes patients. TRIAL REGISTRATION: ChiCTR-IIR-17010311 (Chictr.org).