Developing a Selection Framework for Zinc Ion-Based Biomaterial Design: Guided by the Biosafety Assessment of ZIF-8 and ZnO.

In recent years, nanomaterials have gained widespread use in the biomedical field, with ZIF-8 and ZnO emerging as promising candidates due to their remarkable performance in osteogenesis, angiogenesis, and antimicrobial therapy. However, before advancing these nanomaterials for clinical applications, it is imperative to evaluate their biocompatibility. In particular, comparing nanomaterials with similar biomedical functions is crucial for identifying the most suitable nanomaterials for further development and market entry. Our study aimed to compare the biocompatibility of nano-ZIF-8 and nano-ZnO under the same conditions. We found that nano-ZIF-8 exhibited lower toxicity both in vitro and in vivo compared to nano-ZnO. To gain insights into the underlying mechanisms responsible for this difference, we conducted further experiments to investigate lysosome damage, mitochondrial change, and the occurrence of ferroptosis. Additionally, we performed transcriptome sequencing to analyze the expression of relevant genes, thereby providing robust validation for our findings. In summary, our study highlighted the importance of evaluating nanomaterials with similar biomedical effects. Through this comparative study, we have not only shed light on the superior biocompatibility of nano-ZIF-8 over nano-ZnO, but also contributed valuable insights and methodological references for future material screening endeavors. Ultimately, our study served as a stepping stone toward the development of safer and more effective nanomaterials for various biomedical applications.

Smart Design of ZnFe and ZnFe@Fe Nanoparticles for MRI-Tracked Magnetic Hyperthermia Therapy: Challenging Classical Theories of Nanoparticles Growth and Nanomagnetism.

Iron Oxide Nanoparticles (IONPs) hold the potential to exert significant influence on fighting cancer through their theranostics capabilities as contrast agents (CAs) for magnetic resonance imaging (MRI) and as mediators for magnetic hyperthermia (MH). In addition, these capabilities can be improved by doping IONPs with other elements. In this work, the synthesis and characterization of single-core and alloy ZnFe novel magnetic nanoparticles (MNPs), with improved magnetic properties and more efficient magnetic-to-heat conversion, are reported. Remarkably, the results challenge classical nucleation and growth theories, which cannot fully predict the final size/shape of these nanoparticles and, consequently, their magnetic properties, implying the need for further studies to better understand the nanomagnetism phenomenon. On the other hand, leveraging the enhanced properties of these new NPs, successful tumor therapy by MH is achieved following their intravenous administration and tumor accumulation via the enhanced permeability and retention (EPR) effect. Notably, these results are obtained using a single low dose of MNPs and a single exposure to clinically suitable alternating magnetic fields (AMF). Therefore, as far as the authors are aware, for the first time, the successful application of intravenously administered MNPs for MRI-tracked MH tumor therapy in passively targeted tumor xenografts using clinically suitable conditions is demonstrated.

Efficiency and selectivity of cost-effective Zn-MOF for dye removal, kinetic and thermodynamic approach.

Green synthesis of metal-organic frameworks (MOFs) has attracted a lot of attention as a crucial step for practical industrial applications. In this work, green synthesis of zinc(II) metal-organic framework (Zn-MOF) has been carried out at room temperature. The Zn metal (node) was extracted from spent domestic batteries, and the linker was benzene di-carboxylic acid (BDC). The characterization of the as-prepared Zn-MOF was accomplished by PXRD, FT-IR spectroscopy, SEM, TEM, TGA, and nitrogen adsorption at 77 K. All the characterization techniques strongly supported that as-synthesized Zn-MOF using metallic solid waste Zn is similar to that was reported in the literature. The as-prepared Zn-MOF was stable in water for 24 h without any changes in its functional groups and framework. The prepared Zn-MOF was tested for the adsorption of three dyes, two anionic dyes, aniline blue (AB), and orange II (O(II)) as well as methylene blue (MB), an example of cationic dye from aqueous solution. AB has the highest equilibrium adsorbed amount, qe, of value 55.34 mg g-1 at pH = 7 and 25 °C within 40 min. Investigation of the adsorption kinetics indicated that these adsorption processes could be described as a pseudo-second-order kinetic model. Furthermore, the adsorption process of the three dyes was described well by the Freundlich isotherm model. According to the thermodynamic parameters, the adsorption of AB on the prepared Zn-MOF was an endothermic and spontaneous process. In contrast, it was non-spontaneous and exothermic for the uptake of O(II) and MB. This study complements the business case development model of "solid waste to value-added MOFs."

Biosorption of zinc (II) from synthetic wastewater by using Inula Viscosa leaves as a low-cost biosorbent: Experimental and molecular modeling studies.

The use of biosorption as a strategy for lowering the amount of pollution caused by heavy metals is particularly encouraging. In this investigation, a low-cost and efficient biosorbent, Inula Viscosa leaves were used to remove zinc ions (Zn2+) from synthetic wastewater. A Fourier transform infrared spectroscopy experiment, a scanning electron microscopy experiment, and an energy dispersive X-ray spectroscopy experiment were used to describe the support. Several different physicochemical factors, such as the beginning pH value, contact duration, initial zinc concentration, biosorbent dose, and temperature, were investigated in this study. When the Langmuir, Freundlich, Temkin, Toth, and Redlich-Peterson models were used to match the data from the Inula Viscosa leaves biosorption isotherms, it was found that the biosorption isotherms correspond most closely with the Langmuir isotherm. On the other hand, the kinetic biosorption process was investigated using pseudo-first-order, pseudo-second-order (PS2), and Elovich models. The PS2 model was the one that provided the most accurate description of the biosorption kinetics. The thermodynamics process shows the spontaneous and endothermic character of Zn2+ sorption on Inula Viscosa leaves, which also entails the participation of physical interactions. In addition, the atom-in-molecule analysis, density functional theory, and the conductor like screening model for real solvents, were used to investigate the relationship that exists between quantum calculations and experimental outcomes.

Copper and zinc adsorption from bacterial biomass - possibility of low-cost industrial wastewater treatment.

The increasing interest of all stakeholders to achieve environmental protection with socioeconomic development puts pressure on industrial processes for less negative impact on the environment. The use of biomass for wastewater treatment has increased due to its low costs and technical feasibility. The present study aimed the use of biomass from a waste of known polluted area for the adsorption of Zn and Cu in a fixed-bed reactor. Samples were collected in Cubatão (Brazil) and cultivated in LB medium. Resulting cultivable bacterial communities were identified as Enterococcus faecalis and Pseudomonas aeruginosa. Adsorption experiments were performed varying the metallic ion concentration and the amount of biomass. Adsorption experiments showed efficiency rates up to 90%. As the concentration of metallic ions increased, the adsorption efficiency decreased, indicating that the active sites were saturated. Activated charcoal demonstrated lower adsorption rates than biomass. Elution process showed that HNO3 had better efficiency than HCl. Zn adsorption fitted better for Lineweaver-Burk model (Qmax = 200 mg/g of biomass), while Cu adsorption fitted better for Langmuir model (Qmax = 164 mg/g of biomass). Results here demonstrated that the adsorption of Zn and Cu simulating an industrial wastewater by the biomass from a contaminated area is technically feasible.

The effects of metal cofactors on the reactivity of quercetin 2,4-dioxygenase: synthetic model studies with M(II)-complexes (M = Mn, Co, Ni, Cu, Zn) and assessment of the regulatory factors in catalytic efficacy.

This paper demonstrates the metal ion effects on the quercetin 2,4-dioxygenase (2,4-QD)-like reactivity. For this purpose, a series of five metal(II)-acetato complexes [MII(L)(OAc)] {M = Mn (1OAc), Co (2OAc), Ni (3OAc), Cu (4OAc), Zn (5OAc); OAc = acetate} supported with a newly designed N3O-donor carboxylato ligand L- {L- = 2-((benzyl((6'-methyl-[2,2'-bipyridin]-6-yl)methyl)amino)methyl)benzoate} has been synthesised as models for the active sites of MII-substituted 2,4-QDs. The enzyme-substrate (ES) model complexes [MII(L)(fla)] {M = Mn (1fla), Co (2fla), Ni (3fla), Cu (4fla), Zn (5fla); flaH = flavonol} have been synthesised by reacting flaH with their corresponding acetate-bound complexes in basic conditions. Detailed physicochemical properties of all the compounds are reported. Furthermore, single-crystal X-ray diffractions have been done to determine the structures of the compounds 2OAc·2H2O, 3OAc, 4OAc·CH2Cl2·2H2O, 5OAc·2H2O and 2fla·MeOH. The enzymatic reactivities of complexes 1OAc-5OAc towards the dioxygenation of flavonol have been explored in detail. All the complexes effectively catalyse the oxygenative degradation of flavonol in N,N-dimethylformamide (DMF) medium at 70 °C under multiple-turnover conditions and produce enzyme-type products. Kinetic investigations were performed to see the metal ions' effects on reactivity. The reaction rates vary with the metal ions, showing the order Co > Ni > Zn > Mn > Cu. The studies reveal that the reactivities of the [MII(L)(OAc)] complexes are governed primarily by three factors viz the ES adduct formation constant (Kf), the redox potential (Epa) of the bound fla-/fla˙ couple, and the degree of delocalisation of the fla˙ radical with the metal electrons, which are drastically influenced by the M2+ ions. In the mechanistic interpretation, a single-electron transfer (SET) from the bound-flavonolate to dioxygen has been proposed to generate the catalytically important "M(II)-fla˙" radical and superoxide ion, which react further to bring about the dioxygenation reaction. The identification of the metal(II)-bound flavonoxy radical intermediate for the case of cobalt using EPR spectroscopy and the detection of superoxide ion by NBT2+ test and EPR spin-trapping experiment (DMPO test) are remarkable in envisaging the reaction pathway.

Synthesis and evaluation of a Zn-Al layered double hydroxide for the removal of ochratoxin A. Greenness assessment.

The retention behavior of a dangerous toxin, ochratoxin A (OTA), present in food samples and derivatives was evaluated using Layered Double Hydroxides (LDHs). This nanomaterial composed mostly of zinc and aluminum was synthesized by the co-precipitation method and the obtained solid was characterized by different techniques, such as XRD, FTIR, TGA, SEM, and N2 adsorption-desorption isotherms. Experimental conditions were optimized by chemometric tools. Ochratoxin A determination was performed using an ultra-high-performance liquid chromatography (UHPLC) system coupled to tandem mass spectrometry. From the findings, quantitative removal of the mycotoxin was achieved. Thus, a novel, nanostructured, innocuous, low-cost, easily synthesized material, such as the Zn-Al layered double hydroxide, is proposed for ochratoxin A removal. This might represent an effective and sustainable approach with potential applications to different types of food and feed samples.

Rutin-Zn(II) complex promotes bone formation - A concise assessment in human dental pulp stem cells and zebrafish.

We have assessed the molecular role of Rutin and rutin-Zn(II) complex on osteoblast differentiation and mineralization in human dental pulp cells and zebrafish model. The biocompatibility of the rutin-Zn(II) complex was determined using MTT and chick embryotoxicity assays. Alizarin red staining and ALP measurements were performed to study the osteogenic role of Rutin and rutin-Zn(II) complex at the cellular level in hDPSCs. At molecular level, following rutin and rutin-Zn(II) exposure, the mRNA expression profile of osteoblast markers such Runx2, type 1 col, OC, and ON were investigated. In addition to this, the expression of negative regulators of osteoblast development such Smad7, Smurf1, and HDAC7 waere studied by Real time RT-PCR analysis. The osteogenic role of prepared complex under in vivo was studied by an in-house zebrafish scale model followed by osteoblast differentiation markers expression profiling and Ca:P level measurement by ICP-MS. Rutin and the rutin-Zn(II) complex were found to be non-toxic till 10 µM and increased the expression of osteoblast differentiation marker genes. It also enhanced calcium deposition in both in vitro and in vivo models. Osteogenic property of rutin-Zn(II) in hDPSCs was found be mediated by Smad7, Smurf1, and HDAC7 and enhancing Runx2 expression. Our study warrants the possible use of rutin-Zn(II) as naïve agent or in combination with other bone scaffolding systems/materials for bone tissue engineering applications.

Nano zinc elicited biochemical characterization, nutritional assessment, antioxidant enzymes and fatty acid profiling of rapeseed.

The use of nanomaterials in agriculture is a current need and could be helpful in overcoming food security risks. Brassica napus L. is the third most important crop for edible oil, having double low unsaturated fatty acids. In the present study, we investigated the effects of green synthesized Zn NPs on biochemical effects, antioxidant enzymes, nutritional quality parameters and on the fatty acid profile of rapeseed (B. napus). Plant-mediated synthesis of zinc nanoparticles (Zn NPs) was carried out using Mentha arvensis L. leaf extract followed by characterization through ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-Ray (EDX), and X-Ray diffraction (XRD). NPs exhibited irregular shapes ranging in size from 30-70 nm and EDX analysis confirmed 96.08% of Zn in the sample. The investigated biochemical characterization (protein content, proline content, total soluble sugar (TSS), total flavonoid content (TFC), and total phenolic content (TPC) showed a substantial change on exposure to Zn NPs. A dose-dependent gradual increase was observed in the antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Oil and moisture contents dropped significantly from the control level in the rapeseed (B. napus) varieties. However, different trends in nutritional (Zn, Na+, K+) and fatty acid profiling of B. napus have been noted. This study demonstrates that Zn NPs have the potential to improve the biochemical, nutritional, antioxidant enzymes, and fatty acid profile of B. napus varieties.

Evaluation of the activation of brass apertures in proton therapy using gamma-ray spectrometry and Monte Carlo simulations.

Collimating apertures are used in proton therapy to laterally conform treatment fields to the target volume. While this is a standard technique in passive spreading treatment heads, patient-specific apertures can supplement pencil-beam scanning (PBS) techniques to sharpen the lateral dose fall-off. A radiation protection issue is that proton-induced nuclear reactions can lead to the formation of radionuclides in the apertures. In the experiments of the current study, cylindrical, thick brass targets were irradiated with quasi-monoenergetic proton fields of 100.0 MeV and of 226.7 MeV in PBS mode. The radioactivation of these two brass samples was characterised with a low-level gamma-ray spectrometer. The activation products were scored in a Monte Carlo simulation, too, and compared with the experimental activities. For the high-energy field, 63Zn, 60Cu, and 61Cu were the most important short-lived isotopes regarding the measured specific activity. After irradiation with the 100.0 MeV field, 62Cu, 63Zn, and 60Cu had the highest activity. Regarding long-lived isotopes, which determine the storage time of the used apertures, the isotopes 57Co, 65Zn, 54Mn, 56Co had the largest contribution to the activity. The relative difference of activities between simulation and experiment was typically between 10%-20% for short-lived nuclides and were up to a factor of five larger for long-lived nuclides. Summarising experiments and simulations for both incident proton energies, 62Cu was the most important detected residual nucleus regardless if specific activity or equivalent dose is considered.

Environmental and economical assessment for a sustainable Zn/air battery.

Metal/Air batteries are being developed and soon could become competitive with other battery technologies already in the market, such as Li-ion battery. The main problem to be addressed is the cyclability, although some progress has been recently achieved. A Life Cycle Assessment (LCA) of the manufacturing process of a Zn/Air battery is presented in this article, including raw extraction and process of materials and battery assembly at laboratory scale (cradle to gate approach). The results indicate that Zn/Air battery can be fabricated with low environmental impacts in most categories and only four deserve attention (still being low impacts), such as Human Toxicity (cancer and non-cancer), Freshwater Ecotoxicity and Resource Depletion (the later one depending mainly on Zn use, which is not a critical material, but has a strong impact on this category). Cathode fabrication arises as the subassembly with higher impacts, followed by membrane, then anode and finally electrolyte. An economic cost calculation indicates that if cyclability of Zn/Air batteries is achieved, they can become competitive with other technologies already in the market.

Comparative Assessment of Genotoxic Impacts Induced by Zinc Bulk- and Nano-Particles in Nile tilapia, Oreochromis niloticus.

Fish were separately exposed to 1/2 LC50/96 h values of bulk-Zn and nano-Zn for 7, 14, and 28 days. The induction of micronuclei (MN) and other eight nuclear abnormalities in erythrocytes showed marked time and size dependence. The frequencies of all nuclear anomalies were progressively elevated (p < 0.05) with increasing the time of exposure to both bulk-Zn and nano-Zn. Throughout the study periods, fish exposed to nano-Zn showed the maximum elevation in all studied nuclear anomalies. Based on the fragmented DNA values, both Zn forms induced tissue-specific DNA damage as following gills > liver > muscles. Moreover, nano-Zn exposed groups revealed a maximum percentage of DNA damage among all studied groups, especially after 14 days. The percentage of DNA damage was decreased in all tissues on the 28th day, which reflected the presence of an effective repair mechanism. Finally, nano-Zn exhibited more genotoxic effects than that of its bulk counterparts.

Hydrotransport-Oriented Zn, Cu, and Pb Behavior Assessment and Source Identification in the River Network of a Historically Mined Area in the Hokuroku Basin, Northeast Japan.

Aquatic ecosystems continuously receive potentially hazardous heavy metals from natural and anthropogenic sources. Focusing on the origin of heavy metals, this study aims to estimate the load contribution of tributaries from individual watershed and human drainage and to dissect the source of heavy metals, as commonly required for environmental impact assessment. Using integrated water dynamics, Geographic Information System (GIS), and chemical analysis, we identified and evaluated the heavy metal sources of the Kosaka river system in Hokuroku basin, which is a historically mined area in Northeast Japan, both in the high-water and low-water seasons. The migration and diffusion behaviors of heavy metals along with hydro-transport were analyzed, and the effects of mining activities on regional water quality both in the high-water and low-water seasons were clarified. The results indicate that Zn pollution was obvious in the Kosaka River network, especially in the downstream area. The spatial heterogeneity of heavy metal outflows from tributary watersheds was obvious, and the variations had strong correlations with mine site locations. The heavy metal flows in the mainstream increased sharply in the vicinity downstream of the Kosaka refinery drainage outlets. Compared to the low-water season, the influences of human drainage were slighter in high-water season, with lower contribution rates due to the dilution effect of the greater water discharge. Downscale sampling is effective to identify pollutant sources in regional basins.

Inactivating pathogenic bacteria in greywater by biosynthesized Cu/Zn nanoparticles from secondary metabolite of Aspergillus iizukae; optimization, mechanism and techno economic analysis.

The inactivation of antibiotic resistant Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) seeded in greywater by bimetallic bio-nanoparticles was optimized by using response surface methodology (RSM). The bimetallic nanoparticles (Cu/Zn NPs) were synthesized in secondary metabolite of a novel fungal strain identified as Aspergillus iizukae EAN605 grown in pumpkin medium. Cu/Zn NPs were very effective for inhibiting growth of E. coli and S. aureus. The maximum inactivation was optimized with 0.028 mg mL-1 of Cu/Zn NPs, at pH 6 and after 60 min, at which the reduction of E. coli and S. aureus was 5.6 vs. 5.3 and 5.2 vs. 5.4 log reduction for actual and predicted values, respectively. The inactivation mechanism was described based on the analysis of untreated and treated bacterial cells by Field emission scanning electron microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscopy (AFM) revealed a damage in the cell wall structure due to the effect of Cu/Zn NPs. Moreover, the Raman Spectroscopy showed that the Cu/Zn NPs led to degradation of carbohydrates and amino structures on the bacteria cell wall. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed that the destruction take place in the C-C bond of the functional groups available in the bacterial cell wall. The techno economic analysis revealed that the biosynthesis Cu/Zn NPs is economically feasible. These findings demonstrated that Cu/Zn NPs can effectively inhibit pathogenic bacteria in the greywater.

Ammonium Fluoride Passivation of CdZnTeSe Sensors for Applications in Nuclear Detection and Medical Imaging.

Cadmium zinc telluride selenide (Cd1-xZnxTe1-ySey or CZTS) is one of the emerging CdTe-based semiconductor materials for detecting X- and gamma-ray radiation at or near room temperature (i.e., without cryogenic cooling). Potential applications of CZTS sensors include medical imaging, X-ray detection, and gamma-ray spectroscopy. Chemical passivation of CZTS is needed to reduce the conductivity of Te-rich surfaces, which reduces the noise and improves the device performance. In this study, we focus on the effect of surface passivation of CZTS using a 10% aqueous solution of ammonium fluoride. The effects of the chemical treatment were studied on the leakage current, charge transport measured as the electron mobility-lifetime (µτ) product, and the spectral resolution measured as the full-width at half-maximum (FWHM) of specific peaks. After passivation, the leakage current increased and began to decrease towards pre-passivation levels. The energy resolutions were recorded for eight applied voltages between -35 V and -200 V. The results showed an average of 25% improvement in the detector's energy resolution for the 59.6 keV gamma peak of Am-241. The electron µτ product was unchanged at 2 × 10-3 cm2/V. These results show that ammonium fluoride is effective for chemical passivation of CZTS detectors.

Traceable in-cell synthesis and cytoplasm-to-nucleus translocation of a zinc Schiff base complex as a simple and economical anticancer strategy.

We have proposed a facile and cheap cancer therapeutic strategy by in-cell synthesizing theranostic Zn Schiff base complexes with nuclear targeting and DNA damaging capability. The in-cell synthesis can be traced via a green-to-blue fluorescence shift, and the subsequent cytoplasm-to-nucleus translocation realizes cancer-specific therapy both in vitro and in vivo.

Assessment of silver nanoparticles decorated starch and commercial zinc nanoparticles with respect to their genotoxicity on onion.

High throughput production of silver nanoparticles (AgNPs) having controlled size appropriate for industrial purposes were achieved via using facile and ecofriendly chemical reduction method. Native rice starch was used as reductant for silver ions (Ag+) to silver atoms (Ag0), as well as stabilizing for the obtainable AgNPs. Two different concentrations; 2000 ppm and 4000 ppm were successfully prepared and coded as AgNPs-2000 and AgNPs-4000 respectively. The attained AgNPs were characterized via ultra-visible (UV-vis) spectra, Transmission Electron Microscope (TEM), Energy dispersive X-ray (EDX), Particle size analyzer, polydispersity index (PDI) and zeta potential (ζ-potential). The average particle size of AgNPs (2000 ppm) was 8 nm with PDI = 0.01 which affirm the monodispersity and homogeneity of the produced AgNPs. Meanwhile, the size majority for the as prepared AgNPs (4000 ppm) was 24 nm with PDI = 0.021. Based on the aforementioned data, AgNPs prepared with a high concentration (4000 ppm) compared with the commercialized ZnNPs were used for the genotoxicity study on onion. Root-tips was used for cytogenetic studies using onion (Allium cepa L.) which are excellent materials for cytological and genotoxicity studies. Genotoxicity results explored that, by using AgNPs ≥40 ppm, the abnormalities disturbed chromosomes were observed and detected, that reflects the genotoxicity effect of these nanoparticles at this dose. In addition, the commercial available ZnNPs with the recommended dose (2 g/L) displayed also severe genotoxicity on A. cepa L. root meristem cells.

Evaluation on the stabilization of Zn/Ni/Cu in spinel forms: Low-cost red mud as an effective precursor.

Red mud, which is from the aluminum industry, is a potentially under-utilized resource. Technological processes for using low-cost red mud as an alternative precursor for detoxifying metal pollutants urgently need to be developed. In this study, we systematically investigated the feasibility of using red mud to detoxify metal-containing wastes (e.g., fly ash) via the formation of preferable crystalline phases. To understand the mechanism of metal detoxification by red mud, CuO, NiO, and ZnO were blended with red mud at different weight ratios and the mixtures were then subjected to ceramic-sintering. After sintering, the X-ray diffraction results revealed that all of the metals (i.e., Cu, Ni, and Zn) were able to be crystallographically incorporated into spinel lattices. Sintering the red mud at 1100 °C for 3 h effectively converted the metals into spinels. The mixing weight ratios strongly affected the efficiency of the metal incorporation. The red mud was able to incorporate 15 wt% of metal oxides. The incorporation mechanisms mainly occurred between the metal oxide(s) and hematite. Modified TCLP tests were conducted to further evaluate the metal stabilization performance of the red mud, which demonstrated the leachabilities of ZnO and the sintered red mud + ZnO product. The concentration of leached metal was substantially reduced after the incorporation process, thus demonstrating that red mud can be successfully used to detoxify metals. The results of this study reveal that waste red mud can be feasibly reused as a promising waste-to-resource strategy for stabilizing heavy metal wastes.

Recovery of mtDNA from unfired metallic ammunition components with an assessment of sequence profile quality and DNA damage through MPS analysis.

Recovery of suitable amounts of quality DNA from copper and brass surfaces, like those encountered in ammunition, has been a challenge for the forensic community. The ability of copper ions to rapidly facilitate oxidative damage leading to fragmentation of DNA significantly reduces the pool of templates for PCR amplification. We compared two methods for recovering mitochondrial (mt) DNA from the surface of unfired copper projectiles, brass casings, and aluminum casings, and found that using a cotton swab moistened with 0.5M EDTA was the favored approach, especially when the metallic surface was etched. Degradation was significantly higher for DNA samples recovered from copper and brass surfaces, when compared to aluminum. Massively parallel sequencing (MPS) of the control region, using the PowerSeq™ CRM Nested System kit and the Illumina MiSeq instrument, produced full haplotypes for aluminum samples regardless of the method used to deposit or collect DNA, while less than 60% of the copper and brass samples produced partial or full profile information. Touch DNA collected from copper and brass samples produced higher rates of partial or full MPS profile information (∼88-96%), while collection with 0.5M EDTA produced better results than when collection was performed with water; average of ∼70% versus ∼47%. While MPS data was not impacted by noise in the sequencing process, a higher than expected rate of noise was observed, potentially due to an increase in low-level damage lesions. Noise patterns were strikingly different when compared to control data, suggesting that noisy sites may be predictable when testing samples with high levels of oxidative damage. Library preparation was a poor predictor of MPS data quality, as a large percentage of reads did not align with the reference genome. This may impact the number of samples that can be run when a deep-coverage MPS approach is being considered for analysis of mtDNA heteroplasmy. Overall, when applying an MPS approach to the analysis of mtDNA recovered from ammunition, results are expected from touch DNA, will be limited for copper and brass components when the DNA is exposed to an aqueous environment, and DNA degradation will be accelerated when DNA comes in contact with copper or brass surfaces. Practitioners should consider collecting DNA from metallic surfaces with 0.5M EDTA, as this will maximize yield and mitigate degradation. The results of this study directly impact MPS analysis of minor mtDNA sequence variants from metallic surfaces, and are particularly relevant to forensic investigations.

Gated SPECT myocardial perfusion imaging with cadmium-zinc-telluride detectors allows real-time assessment of dobutamine-stress-induced wall motion abnormalities.

BACKGROUND: Left ventricular (LV) ejection fraction (EF) during high dobutamine stress (HD) by real-time gated-SPECT myocardial perfusion imaging (MPI) on a cadmium-zinc-telluride (CZT) gamma camera was validated versus cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS: After injecting 99mTc-tetrofosmin (320 MBq) in 50 patients (mean age 64 +/- 11 years), EF at rest and post-stress as well as relevant changes in EF at HD (ΔEF ≥ 5%) were assessed. CZT and CMR rest EF values yielded an excellent correlation and agreement (r = 0.96; P < 0.001; Bland-Altman limits of agreement (BA): + 0 to 14.8%). HD EF acquisition was feasible using CZT and correlated better to HD CMR EF than did post-stress CZT EF (r = 0.85 vs 0.76, respectively, all P < 0.001). Agreement in ΔEF detection between HD CMR and immediate post-stress CZT (reflecting standard acquisition using conventional SPECT camera unable to scan during stress) was 45%, while this increased to 85% with real-time HD CZT scan. CONCLUSION: Real-time ultrafast dobutamine gated-SPECT MPI with a CZT device is feasible and provides accurate measurements of HD LV performance.