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Seminal stains acquired from fabric surfaces stand as pivotal biological evidence of utmost significance for elucidating sexual assault cases. The ability to determine the temporal aspect of a forensic incident via the analysis of a biological specimen found at the crime scene is crucial in resolving most cases. This study aimed to investigate the time-dependent change in the microbiota structure of human seminal stains exposed to indoor environmental conditions. Stains on polyester fabric generated using semen samples from five male volunteers were kept indoors for varying durations of up to 20 days, followed by sequencing of the V1–V9 regions of the 16S rRNA gene of the microbial DNA extracted from the stains. The acquired data provided the taxonomic composition, and microbial alterations across different days were examined. The most abundantly detected phyla in all samples were Firmicutes, Proteobacteria, and Bacteroidetes, and the relative abundances of bacteria were observed to change over time. Statistically significant changes at the species level were found for Treponema medium, Corynebacterium tuberculostearicum, Faecalibacterium prausnitzii, and Anaerostipes hadrus. Alterations observed in the samples between the analyzed time periods were investigated. The changes during the specified time periods were examined, identifying rare bacterial species that were initially present on certain days but later ceased to exist in the environment. Conversely, bacterial species that were absent before exposure but emerged at a later stage were also identified. The findings of this study demonstrate that species-level evaluations, in particular, can provide crucial insights into semen stain age. [ABSTRACT FROM AUTHOR]

Cryo-electron microscopy was developed as a powerful tool for imaging biological specimens in near-native conditions. Nowadays, advances in technology, equipment and computations make it possible to obtain structures of biomolecules with near-atomic resolution. Furthermore, cryo-electron tomography combined with continuous specimen tilting allows structural analysis of heterogeneous biological specimens. In particular, when combined with a cryo-focused ion beam scanning electron microscope, it becomes possible to directly analyse the structure of the biomolecules within cells, a process known as in situ cryo-electron tomography. This technique has the potential to visualize cytoplasmic zoning, involving liquid–liquid phase separation, caused by biomolecular networks in aqueous solutions, which has been the subject of recent debate. Here, we review advances in structural studies of biomolecules to study cytoplasmic zoning by in situ cryo-electron tomography. [ABSTRACT FROM AUTHOR]

Correlative microscopy and block-face imaging (CoMBI) is an imaging method, which is characterized by the ability to obtain both serial block-face images as a 3-dimentional (3D) dataset and sections for 2-dimentional (2D) light microscopic analysis. These 3D and 2D morphological data can be correlated with each other to facilitate data interpretation. CoMBI is an easy-to-install and low-cost 3D imaging method since its system can be assembled by the researcher using a regular microtome, consumer digital camera, and some self-made devices, and its installation and instruction manuals are open-source. After the first release of CoMBI method from our laboratory, CoMBI systems have been installed in more than a dozen laboratories and are used for 3D analysis of various biological specimens. Typical application of CoMBI is 3D anatomical analysis using the natural color and contrast of the specimen. We have been using CoMBI for analyzing human brain to obtain the fine 3D anatomy as a reference to determine the causes of neurological diseases and to improve the effectiveness of surgery. Recently, we have been using CoMBI for detecting the colors of chromogens, which are used for labeling specific molecules. Mouse embryos colored with X-gal, a conventional chromogen for detecting LacZ products, were imaged using CoMBI, and the 3D distribution of X-gal was successfully visualized. Thus, CoMBI can now be used for many purposes, including 3D anatomical analysis, 2D microscopy using sections, and 3D distribution of specific molecules. These suggest that CoMBI should be more widely used in the field of biological research. [ABSTRACT FROM AUTHOR]

The effectiveness of highly polar agents in cancer treatment is well recognized, but their physicochemical properties make their analytical determination a demanding task. Their analysis requires peculiar sample preparation and chromatographic separation, which heavily impacts the precision of such an analytical method. As a case study, we chose a polar cytotoxic bleomycin, which is a mixture of complexing congeners with relatively high molecular mass, a fact that creates an added challenge in regard to its detection via electrospray mass spectrometry. These issues combined lead to a deprived method performance, so the aim of this study is manifold, i.e., to optimize, validate, and establish quality performance measures for determination of bleomycin in pharmaceutical and biological specimens. Quantification of bleomycin is done at diametrically different concentration levels: at the concentrations relevant for analysis of pharmaceutical dosage forms it is based on a direct reversed-phase HPLC-UV detection, involving minimum sample pretreatment. On the contrary, analysis of bleomycin in biological specimens requires phospholipid removal and protein precipitation followed by HILIC chromatography with MS/MS detection of bleomycin A2 and B2 copper complexes being the predominant species. This study further attempts to solve the traceability issue in the absence of certified reference standards, determines measurement uncertainty, investigates BLM stability and method performance characteristics, and, last but not least, provides an explanatory example of how a method quality assurance procedure should be established in case of an exceedingly complex analytical method. [ABSTRACT FROM AUTHOR]

Background: Qihuang needle therapy is a newly developed acupuncture therapy to treat tic disorders in clinical practice. However, the mechanism to reduce tic severity remains unknown. Changes in intestinal flora and circulation metabolites are perhaps the potential pathogenesis of tic disorders. As a result, we present a protocol for a controlled clinical trial using multi-omics analysis to probe the mechanism of the Qihuang needle in managing tic disorders. Methods: This is a matched-pairs design, controlled, clinical trial for patients with tic disorders. Participants will be allocated to either an experimental group or a healthy control group. The main acupoints are Baihui (GV20), Yintang (EX-HN3), and Jueyinshu (BL14). The experimental group will receive Qihuang needle therapy for a month, while the control group will receive no interventions. Expected outcomes: The change in the severity of the tic disorder is set as the main outcome. Secondary outcomes include gastrointestinal severity index and recurrence rate, which will be calculated after a 12-week follow-up. Gut microbiota, measured by 16S rRNA gene sequencing; serum metabolomics, assessed via LC/MS; and serum zonulin, assessed by enzyme-linked immunosorbent assay (ELISA), will be used as biological specimen analysis outcomes. The present study will investigate the possible interactions between intestinal flora and serum metabolites and the improvement of clinical profiles, which may elucidate the mechanism of Qihuang needle therapy for tic disorders. [ABSTRACT FROM AUTHOR]

High‐resolution magic angle spinning (HRMAS) NMR, an approach for intact biological material analysis discovered more than 25 years ago, has been advanced by many technical developments and applied to many biomedical uses. This article provides a history of its discovery, first by explaining the key scientific advances that paved the way for HRMAS NMR's invention, and then by turning to recent developments that have profited from applying and advancing the technique during the last 5 years. Developments aimed at directly impacting healthcare include HRMAS NMR metabolomics applications within studies of human disease states such as cancers, brain diseases, metabolic diseases, transplantation medicine, and adiposity. Here, the discussion describes recent HRMAS NMR metabolomics studies of breast cancer and prostate cancer, as well as of matching tissues with biofluids, multimodality studies, and mechanistic investigations, all conducted to better understand disease metabolic characteristics for diagnosis, opportune windows for treatment, and prognostication. In addition, HRMAS NMR metabolomics studies of plants, foods, and cell structures, along with longitudinal cell studies, are reviewed and discussed. Finally, inspired by the technique's history of discoveries and recent successes, future biomedical arenas that stand to benefit from HRMAS NMR‐initiated scientific investigations are presented. [ABSTRACT FROM AUTHOR]

Simple Summary: Dairy cows are commonly affected by mastitis, which causes huge economic losses to the dairy industry worldwide. This work aimed to study this disease by comparing multiple biological specimens (feces, serum, and urine) from individuals with or without clinical mastitis. Integrated analysis of metabolome changes across several key biofluids could facilitate knowledge discovery and reliable identification of potential biomarkers, which could in turn be used to shed light on the early diagnosis of dairy cow mastitis in its subclinical form. To the best of our knowledge, this is the first work dedicated to providing quantitative information on the multi-matrix metabolome of dairy cows with/without clinical mastitis by untargeted 1H-NMR. Several pathways related to energy metabolism and amino acid metabolism have been highlighted to explain the mechanisms of the changes in the dairy cow metabolome related to clinical mastitis. Our findings are the first to provide an integrated view and better understanding of the metabolic mechanism of clinical mastitis, useful for the development of regulated strategies to improve the metabolic status of mastitic dairy cows. Due to huge economic losses to the dairy industry worldwide, mastitis can be considered as one of the most common diseases in dairy cows. This work aimed to study this disease by comparing multiple biological specimens (feces, serum, and urine) from individuals with or without clinical mastitis. This was performed by a single analytical platform, namely 1H-NMR, through a multi-matrix strategy. Thanks to the high reproducibility of 1H-NMR, we could characterize 120 molecules across dairy cow feces, serum, and urine. Among them, 23 molecules were in common across the three biofluids. By integrating the results of multi-matrix metabolomics, several pathways pertaining to energy metabolism and amino acid metabolism appeared to be affected by clinical mastitis. The present work wished to deepen the understanding of dairy cow mastitis in its clinical form. Simultaneous analysis of metabolome changes across several key biofluids could facilitate knowledge discovery and the reliable identification of potential biomarkers, which could be, in turn, used to shed light on the early diagnosis of dairy cow mastitis in its subclinical form. [ABSTRACT FROM AUTHOR]

Marseilleviridae is a family of giant viruses, showing a characteristic internal membrane with extrusions underneath the icosahedral vertices. However, such large objects, with a maximum diameter of 250 nm are technically difficult to examine at sub-nanometre resolution by cryo-electron microscopy. Here, we tested the utility of 1 MV high-voltage cryo-EM (cryo-HVEM) for single particle structural analysis (SPA) of giant viruses using tokyovirus, a species of Marseilleviridae, and revealed the capsid structure at 7.7 Å resolution. The capsid enclosing the viral DNA consisted primarily of four layers: (1) major capsid proteins (MCPs) and penton proteins, (2) minor capsid proteins (mCPs), (3) scaffold protein components (ScPCs), and (4) internal membrane. The mCPs showed a novel capsid lattice consisting of eight protein components. ScPCs connecting the icosahedral vertices supported the formation of the membrane extrusions, and possibly act like tape measure proteins reported in other giant viruses. The density on top of the MCP trimer was suggested to include glycoproteins. This is the first attempt at cryo-HVEM SPA. We found the primary limitations to be the lack of automated data acquisition and software support for collection and processing and thus achievable resolution. However, the results pave the way for using cryo-HVEM for structural analysis of larger biological specimens. [ABSTRACT FROM AUTHOR]

Simple Summary: Stress in domestic animals can lead to serious consequences. We reviewed biological specimens (fluid and non-fluid types), that are capable of evaluating either cortisol or corticosterone steroid levels as major biomarkers of stress (acute or chronic) in different animal species. Proper methods to evaluate the chronic stress of animals through hormonal analysis can save time and cost of experiments in clinical laboratories due to different research groups applying different techniques for preparation, extraction, and analysis of the biological specimens that may result in fluctuating and inaccurate values. In addition, we reviewed the immunoassays such as singleplex immunoassays (ELISA) and multiplex immunoassays as the most common method used for detecting multi-biomarkers of stress. In this review, we aimed to: (1) explain the classification of stress, (2) discuss the matrices that can be used as biomarkers of stress, their comparison, and limitations, and present the most important reliable matrix, (3) compare the analytical methods for measuring stress hormones after sample preparation to determine the result. In this review, we have discussed the method of sample collection, sex and age effects, the body regions to be selected, and the method of analysis of cortisol and corticosterone in different body indices that may be used from time to time. We also compared the advantages and disadvantages of each matrix and technique for analyzing stress hormones. When studying stress in animals, it is important to understand the types of stress and their classification, and how to assess the stress levels in different animal species using different matrices accurately and precisely. The classification of stress types helps to distinguish between good stress (eustress) and bad stress (distress). Hence, first, it is crucial to assess the animal's level of stress in a non-intrusive manner and second to identify the type of stress that is best suited to its environment. Third, it is also important to analyze the obtained samples using a suitable method to increase the validity of stress hormone measurements. Therefore, in this review, we aim to: (1) explain the classification of stress, (2) discuss the wide range of body matrices (e.g., saliva, milk, hair, urine, feces, sweat, fins, etc.) that can be used as samples to evaluate stress levels, as well as their comparisons and limitations, and present the reliable matrices for measuring stress hormones with special emphasis on hair, (3) compare the analytical methods for measuring stress hormones after sample preparation. Despite some literature that does not include hair as a reliable matrix for evaluating stress levels, hair is one of the matrices for measuring long-term stress hormone accumulations. This review discusses some factors that influence the level of stress hormones in the hair. By understanding these issues, the scientific community will not only be able to improve the understanding of stress and biomarker evaluation but also suggest how to deal with the consequences of stress in future research. [ABSTRACT FROM AUTHOR]

Normal levels of thyroid hormones (THs) are essential for a normal pregnancy outcome, fetal growth and the normal function of the central nervous system. Hypothyroidism, a common endocrine disorder during pregnancy, is a significant metabolic factor leading to cognitive impairments. It is essential to investigate whether patients with thyroid dysfunction may present an altered circulative and excreted metabolic profile, even after receiving treatment with thyroxine supplements. NMR metabolomics was employed to analyze 90 serum and corresponding colostrum samples. Parallel analyses of the two biological specimens provided a snapshot of the maternal metabolism through the excretive and circulating characteristics of mothers. The metabolomics data were analyzed by performing multivariate statistical, biomarker and pathway analyses. Our results highlight the impact of hypothyroidism on metabolites' composition during pregnancy and lactation. Thyroid disorder causing metabolite fluctuations may lead to impaired lipid and glucose metabolic pathways as well as aberrant prenatal neurodevelopment, thus posing a background for the occurrence of metabolic syndrome or neurogenerative diseases later in life. This risk applies to not only untreated but also hypothyroid women under replacement therapy since our findings in both biofluids framed a different metabolic phenotype for the latter group, thus emphasizing the need to monitor women adequately after treatment initiation. [ABSTRACT FROM AUTHOR]

Specimen preparation is a critical but challenging step in high-resolution cryogenic electron microscopy (cryo-EM) structural analysis of macromolecules. In the past decade, graphene has gained much recognition as the supporting substrate to optimize cryo-EM specimen preparation. It improves macromolecule embedding in ice, reduces beam-induced motion, while imposing negligible background noise. Various types of graphene-coated cryo-EM grids were implemented to improve the robustness and efficiency of specimen preparation. Graphene functionalization by different means has been proved specifically useful in addressing challenges related to the air-water interface (AWI), such as preferential orientation and sample denaturation. Graphene sandwich specimen preparation sets a new direction to explore in cryo-EM analysis of biological specimens. In this review, we discuss the current challenges and future prospects of graphene application in cryo-EM analysis of macromolecules. • This work reviews the use of graphene as the supporting substrate for preparing cryo-EM specimens. • Graphene enables improved ice-embedding of particles, minimal background noise, and reduced motion and charging effect. • Graphene can be functionalized by various strategies to modulate the manner of interaction with target macromolecules. • Graphene functionalized with affinity ligands exhibits high affinity and specificity in binding to target macromolecules. [ABSTRACT FROM AUTHOR]

The small-scale tuna longline fishery operating on the coast of Nayarit started recently in 2013. We provide the first detailed report on some biological parameters for the yellowfin tuna (YFT) in Nayarit (Mexico). We sampled 584 YFT, representing a catch of 25.5 t. We fit the length-weight relationship, used the t-test to determine the type of growth, and estimated the selectivity curve. The total length data varied from 73.0 to 228.0 cm, with a mean of 153.0 ± 23.5 cm (mean ± SD). Weight ranged from 5.8 to 128.0 kg, with a mean of 43.7 ± 19.4 kg. Length-weight fitting results and the t-test suggested negative allometric growth. Selectivity fitting results suggested that selectivity follows an asymptotic pattern. Our results represent the first step into gathering information to establish research and monitoring programs for the YFT on the Pacific coast of Mexico. The information provided in this study could help develop proper regulations to assure a well-managed fishery and the sustainable exploitation of YFT in Nayarit. [ABSTRACT FROM AUTHOR]

Biology has become a prime area for the deployment of deep learning and artificial intelligence (AI), enabled largely by the massive data sets that the field can generate. Key to most AI tasks is the availability of a sufficiently large, labeled data set with which to train AI models. In the context of microscopy, it is easy to generate image data sets containing millions of cells and structures. However, it is challenging to obtain large-scale high-quality annotations for AI models. Here, we present HALS (Human-Augmenting Labeling System), a human-in-the-loop data labeling AI, which begins uninitialized and learns annotations from a human, in real-time. Using a multi-part AI composed of three deep learning models, HALS learns from just a few examples and immediately decreases the workload of the annotator, while increasing the quality of their annotations. Using a highly repetitive use-case—annotating cell types—and running experiments with seven pathologists—experts at the microscopic analysis of biological specimens—we demonstrate a manual work reduction of 90.60%, and an average data-quality boost of 4.34%, measured across four use-cases and two tissue stain types. [ABSTRACT FROM AUTHOR]

Benzodiazepines are a commonly prescribed class of drugs that have the potential for abuse. The Palm Beach County Sheriff's Office received drug seizure submissions that included novel and/or nonroutine benzodiazepines of increasing prevalence from 2017 to 2019. This prompted the development of a method of analysis for these compounds in biological specimens. The method tests for 16 novel and nonroutine benzodiazepines and suvorexant in whole blood by liquid chromatography–tandem mass spectrometry (LC–MS-MS). The target analytes included bromazepam, clobazam, clonazolam, clotiazepam, diclazepam, estazolam, etizolam, flualprazolam, flubromazepam, flubromazolam, loprazolam, lormetazepam, phenazepam, prazepam, suvorexant, tetrazepam and triazolam. The method uses 200 µL of sample, protein precipitation and an instrument run-time of 8 min. The limit of detection was either 1 or 5 ng/mL and the limit of quantitation was either 5 or 25 ng/mL depending on the analyte. The method was validated for quantitative analysis for 15 out of the 17 analytes. Flubromazepam and prazepam were validated for qualitative identification only. A quadratic calibration model (r 2 > 0.990) with 1/x weighting was used for all analytes for quantitative analysis. The calibration range was either 5–100 or 25–500 ng/mL depending on the analyte. The coefficient of variation of replicate analyses was within 14% and bias was within ±14%. The method provides a sensitive, efficient and robust procedure for the quantitation and/or qualitative identification of select novel and nonroutine benzodiazepines and suvorexant using LC–MS-MS and a sample volume of 200 µL. [ABSTRACT FROM AUTHOR]

To study the compressional forces exerted by a bundle of living stiff filaments pressing on a surface, akin to the case of an actin bundle in filopodia structures, we have performed particulate molecular dynamics simulations of a grafted bundle of parallel living (self-assembling) filaments, in chemical equilibrium with a solution of their constitutive monomers. Equilibrium is established as these filaments, grafted at one end to a wall of the simulation box, grow at their chemically active free end, and encounter the opposite confining wall of the simulation box. Further growth of filaments requires bending and thus energy, which automatically limit the populations of longer filaments. The resulting filament sizes distribution and the force exerted by the bundle on the obstacle are analyzed for different grafting densities and different sub- or supercritical conditions, these properties being compared with the predictions of the corresponding ideal confined bundle model. In this analysis, non-ideal effects due to interactions between filaments and confinement effects are singled out. For all state points considered at the same temperature and at the same gap width between the two surfaces, the force per filament exerted on the opposite wall appears to be a function of a rescaled free monomer density ρ⁁1eff. This quantity can be estimated directly from the characteristic length of the exponential filament size distribution P observed in the size domain where these grafted filaments are not in direct contact with the wall. We also analyze the dynamics of the filament contour length fluctuations in terms of effective polymerization (U) and depolymerization (W) rates, where again it is possible to disentangle non-ideal and confinement effects. [ABSTRACT FROM AUTHOR]

Purpose: The article reports on a comparative analysis of biological specimens of lung tissues collected from workers with pulmonary fibrosis induced by internal exposure to plutonium alpha-particles (plutonium-induced pulmonary fibrosis [PuPF]) and with etiologically different pulmonary fibrosis (non-PuPF) that developed as an outcome of a chronic obstructive pulmonary disease (COPD). Materials and methods: To perform histological examinations, lung tissues were sampled during autopsy. Six samples of various lung regions (the apical region, the lingula of the left lung and the inferior lobe) were collected from each donor. The resected tissue samples were fixed in 10% neutral-buffered formalin during 24 h and embedded into paraffin blocks (FFPE). FFPE blocks with lung tissue specimens collected from 56 workers with PuPF, 34 workers with non-PuPF and 35 workers without any lung disease were used in the study. To perform microscopic examination, lung tissue specimens were hematoxylin and eosin stained. To examine the connective-tissue scaffold of lung stroma and identify foci of pulmonary fibrosis, the cut sections of paraffin blocks were stained by Van Gizon's method (to assess the total volume of fibrosis-affected tissues), Gomori's technique (to define the reticular scaffold of lung stroma) and Weigert's technique (to examine elastic fibers). Morphological patterns of all biological specimens were studied using immunohistochemistry. To fit the empirical data, the Weibull's model was used. Results and conclusions: The study found qualitative and quantitative morphological features specific for PuPF compared to non-PuPF. The study demonstrated that hyper-production of collagen type V plays a key role in PuPF. The collagen type V content in fibrotic foci in lung tissue specimens from workers with PuPF was found to be increased. [ABSTRACT FROM AUTHOR]

High amounts of cholesterol have been definitely associated with the pathogenesis of several diseases, including metabolic and neurodegenerative disorders, cardiovascular diseases, and cancer. In all these pathologies the exacerbation of pro-oxidant and inflammatory responses is a consistent feature. In this scenario, species derived from enzymatic and non-enzymatic cholesterol oxidation, namely oxysterols, are strongly suspected to play a primary role. The consideration of these bioactive lipids is therefore helpful in investigating pathological mechanisms and may also acquire clinical value for the diagnosis and treatment of diseases. For this purpose and considering that a great number of oxysterols may be present together in the body, the employment of lipidomics technology certainly represents a powerful strategy for the simultaneous detection and characterization of these compounds in biological specimens. In this review, we will discuss the applicability of the lipidomics approach in the study of the association between oxysterols and diseases. Cholesterol is a fundamental lipid in the development and physiological function of mammals, thus alterations of its plasma and tissue levels, due to incorrect diet or aberrant metabolism, are associated with several chronic diseases, many of which are characterized by activation of oxidative stress and inflammation. As a consequence of cholesterol enzymatic and non-enzymatic oxidation, a wide spectrum of compounds, named oxysterols, are produced. These molecules are provided with powerful biological activities, and are likely the actual mediators of many of the cholesterol pathophysiological effects. Their application as biomarkers in complex biological specimens is therefore gaining increasing attention. For this purpose, the most powerful approach can be offered by highly sensitive and selective lipidomics techniques. Image 1 • Cholesterol is linked to oxidative stress- and inflammation-related diseases. • Enzymatic and non-enzymatic cholesterol oxidation leads to bioactive oxysterols. • Lipidomics is a powerful technique for oxysterol analysis in biological specimens. • Lipidomics data may associate oxysterols with cholesterol-related pathologies. [ABSTRACT FROM AUTHOR]

This is the first report regarding the characterization of the new synthetic cannabinoid 4F‐MDMB‐BINACA. 4F‐MDMB‐BINACA was first analytically confirmed in seized drug material using gas chromatography–mass spectrometry (GC‐MS), liquid chromatography–quadrupole time‐of‐flight mass spectrometry (LC‐QTOF), and nuclear magnetic resonance (NMR) spectroscopy. Subsequent to this characterization, 4F‐MDMB‐BINACA was detected in biological specimens collected as part of forensically relevant casework, including medicolegal death investigations and drug impaired driving investigations, from a variety of regions in the United States. Further analysis of biological specimens resulted in the identification of the metabolites 4F‐MDMB‐BINACA 3,3‐dimethylbutanoic acid and 4‐OH‐MDMB‐BINACA. 4F‐MDMB‐BINACA is appearing with increasing frequency as a contributory factor in deaths, creating morbidity and mortality risks for drug users. Laboratories must be aware of its presence and impact, incorporating 4F‐MDMB‐BINACA into workflows for detection and confirmation. [ABSTRACT FROM AUTHOR]

The analysis of biological specimens collected at autopsy for the presence of exogenous insulin(s) is of special interest in select death investigations as they may be suspected in the cause of a death. Technical challenges include the limited stability of insulin, and the forensic requirement of differentiating endogenous insulin from pharmaceutical analogs. A novel method was developed for the detection and quantification of human insulin, Glulisine, Lispro, Aspart, Glargine and Detemir in vitreous fluid. An immunoaffinity extraction procedure is performed followed by separation of the insulin α- and β-chains. Liquid chromatography tandem mass spectrometry analysis of the β-chain allows for the unequivocal identification of each insulin analog. The analytical measurement range for each insulin was 0.5–25 ng/mL. The method was evaluated for accuracy, precision, carryover, interferences and stability. Eight vitreous fluid samples collected from cases where untoward insulin use was suspected were subjected to analysis. Positive results were obtained from three samples, and a detailed case history is provided for one of these cases. Even though insulin instability in postmortem biological fluid remains a challenge, this method allows for a reliable forensic-level analysis in vitreous fluid. [ABSTRACT FROM AUTHOR]

The revised Common Rule includes a new option for the conduct of secondary research with identifiable data and biospecimens: regulatory broad consent. Motivated by concerns regarding autonomy and trust in the research enterprise, regulators had initially proposed broad consent in a manner that would have rendered it the exclusive approach to secondary research with all biospecimens, regardless of identifiability. Based on public comments from both researchers and patients concerned that this approach would hinder important medical advances, however, regulators decided to largely preserve the status quo approach to secondary research with biospecimens and data. The Final Rule therefore allows such research to proceed without specific informed consent in a number of circumstances, but it also offers regulatory broad consent as a new, optional pathway for secondary research with identifiable data and biospecimens. In this article, we describe the parameters of regulatory broad consent under the new rule, explain why researchers and research institutions are unlikely to utilize it, outline recommendations for regulatory broad consent issued by the Secretary's Advisory Committee on Human Research Protections (SACHRP), and sketch an empirical research agenda for the sorts of questions about regulatory broad consent that remain to be answered as the research community embarks on Final Rule implementation. [ABSTRACT FROM AUTHOR]

Pre-processing is an essential step in the analysis of spectral data. Mid-IR spectroscopy of biological samples is often subject to instrumental and sample specific variances which may often conceal valuable biological information. Whilst pre-processing can effectively reduce this unwanted variance, the plethora of possible processing steps has resulted in a lack of consensus in the field, often meaning that analysis outputs are not comparable. As pre-processing is specific to the sample under investigation, here we present a systematic approach for defining the optimum pre-processing protocol for biofluid ATR-FTIR spectroscopy. Using a trial-and-error based approach and a clinically relevant dataset describing control and brain cancer patients, the effects of pre-processing permutations on subsequent classification algorithms were observed, by assessing key diagnostic performance parameters, including sensitivity and specificity. It was found that optimum diagnostic performance correlated with the use of minimal binning and baseline correction, with derivative functions improving diagnostic performance most significantly. If smoothing is required, a Sovitzky–Golay approach was the preferred option in this investigation. Heavy binning appeared to reduce classification most significantly, alongside wavelet noise reduction (filter length ≥6), resulting in the lowest diagnostic performances of all pre-processing permutations tested. [ABSTRACT FROM AUTHOR]

Careful collection and organization of biological specimens and their associated data are at the core of field research (e.g., ecology, genetics). Fieldwork data are often collected by handwriting or unsystematically via an electronic device (e.g., laptop), a process that is time‐intensive, disorganized, and may lead to transcription errors, as data are copied to a more permanent repository. SamplEase is an iOS and Android application that is designed to ease the process of collecting biological specimen data in the field (data associated with biological samples, such as location, age, and sex). In addition to biological specimen data, SamplEase allows for the assignment of photographs to each collected sample, which provides visual records of each specimen in its environment. SamplEase outputs biological specimen data in a tabular format, facilitating subsequent analyses and dissemination. Despite the simplicity of SamplEase, no similar data management application is readily available for researchers. SamplEase is an iOS and Android application that is designed to ease the process of collecting biological specimen data in the field. SamplEase also outputs biological specimen data in a tabular format, facilitating subsequent analyses and dissemination. [ABSTRACT FROM AUTHOR]

• Kratom is emerging worldwide as a "legal" herbal drug of abuse. • Alkaloids are the pharmacologically active secondary metabolites. • Extraction and analysis of alkaloids in plant and biological samples are reviewed. • Analytical techniques are evaluated for their ability to distinguish stereoisomers. • Advantages and drawback of analytical techniques are discussed. Mitragyna speciosa or kratom is emerging worldwide as a "legal" herbal drug of abuse. An increasing number of papers is appearing in the scientific literature regarding its pharmacological profile and the analysis of its chemical constituents, mainly represented by alkaloids. However, its detection and identification are not straightforward as the plant material is not particularly distinctive. Hyphenated techniques are generally preferred for the identification and quantification of these compounds, especially the main purported psychoactive substances, mitragynine (MG) and 7-hydroxymitragynine (7-OH-MG), in raw and commercial products. Considering the vast popularity of this recreational drug and the growing concern about its safety, the analysis of alkaloids in biological specimens is also of great importance for forensic and toxicological laboratories. The review addresses the analytical aspects of kratom spanning the extraction techniques used to isolate the alkaloids, the qualitative and quantitative analytical methods and the strategies for the distinction of the naturally occurring isomers. [ABSTRACT FROM AUTHOR]

Both static and time-dependent mechanical factors can have a profound impact on cell and tissue function, but it is challenging to measure the mechanical properties of soft materials at the scale which cells sense. Multimode ultrasound viscoelastography (MUVE) uses focused ultrasound pulses to both generate and image deformations within soft hydrogels non-invasively, at sub-millimeter resolution, and in 3D. The deformation and strain over time data are used to extract quantitative parameters that describe both the elastic and viscoelastic properties of the material. MUVE was used in creep mode to characterize the viscoelastic properties of 3D agarose, collagen, and fibrin hydrogels. Quantitative comparisons were made by extracting characteristic viscoelastic parameters using Burger's lumped parameter constitutive model. Spatial resolution of the MUVE technique was found to be approximately 200 μm, while detection sensitivity, defined as the capability to differentiate between materials based on mechanical property differences, was approximately 0.2 kPa using agarose hydrogels. MUVE was superior to nanoindentation and shear rheometry in generating consistent microscale measurements of viscoelastic behavior in soft materials. These results demonstrate that MUVE is a rapid, quantitative, and accurate method to measure the viscoelastic mechanical properties of soft 3D hydrogels at the microscale, and is a promising technique to study the development of native and engineered tissues over time. [ABSTRACT FROM AUTHOR]

Titanium possesses mechanical property and excellent biocompatibility but yet suffers from bioinertness and poor osteoblasts adhesion. In this work, minTBP-1 was employed to produce a modified IGF-1 endowed with directionality toward Ti surface. It demonstrated that the modified IGF-1 uniformly covered on titanium surface and the surface hydrophilicity was significantly increased. Osteoblasts exhibited increased cell adhesion and mineralization. Our results illustrate that minTBP-1-IGF-1 could produce significant enhancement in osteoblasts adherence, mineralization and maturation. [ABSTRACT FROM AUTHOR]

Ti6Al4V is a popular biomaterial for load-bearing implants for bone contact, which can be fabricated by additive manufacturing technologies. Their long-term success depends on their stable anchoring in surrounding bone, which in turn depends on formation of new bone tissue on the implant surface, for which adhesion and proliferation of bone-forming cells is a pre-requisite. Hence, surface coatings which promote cell adhesion and proliferation are desirable. Here, Ti6Al4V discs prepared by additive manufacturing (EBM) were coated with layers of pectins, calcium-binding polysaccharides derived from citrus (C) and apple (A), which also contained alkaline phosphatase (ALP), the enzyme responsible for mineralization of bone tissue. Adhesion and proliferation of human bone marrow stromal cells (hBMSC) were assessed. Proliferation after 7 days was increased by A-ALP coatings and, in particular, by C-ALP coatings. Cell morphology was similar on coated and uncoated samples. In conclusion, ALP-loaded pectin coatings promote hBMSC adhesion and proliferation. [ABSTRACT FROM AUTHOR]

Solid phase extraction (SPE) and solid phase microextraction (SPME) are among the most significant sample clean-up and pretreatment techniques, which have attracted a considerable interest in the pre-concentration and determination of a wide variety of analytes in biological, pharmaceutical, environmental, industrial and food samples. The purpose of this review article is to focus on the latest advancements and applications of SPE and SPME methods based on new nanomaterial adsorbents for separation, concentration and determination of different analytes in biological media. To this end, some sorbents such as metal organic frameworks, molecularly/ion-imprinted polymers, carbon nanotubes, magnetic nanoparticles, graphene and graphene oxide, and metallic nanoparticles are discussed here. [ABSTRACT FROM AUTHOR]

The number of emerging novel stimulants modified based on beta-keto variations of amphetamine-like substances continues to rise. Dibutylone reports described in the medical and toxicological literature are limited, therefore little information is available in terms of quantitative confirmation or metabolism. During this study, authentic human specimens, including blood, urine, vitreous humor, oral fluid and liver were quantitatively and qualitatively analyzed for the presence of dibutylone and butylone, with paired case history and demographic information. Dibutylone concentrations were variable across all specimen types, specifically ranging from 10 to 1,400 ng/mL in postmortem blood specimens. The metabolic profile of dibutylone was mapped by in vitro incubation with human liver microsomes (HLM). Samples were analyzed using a SCIEX TripleTOF® 5600+ quadrupole time-of-flight mass spectrometer. Data processing was conducted using MetabolitePilot™. Authentic human specimens, including blood, urine, vitreous humor, oral fluid and liver, were utilized for in vivo verification of five HLM-generated metabolites in analytically confirmed cases of dibutylone use. Butylone was confirmed as a metabolite of dibutylone, but issues involving co-ingestion of these two novel stimulants or potential co-existence from synthesis lead to ineffectiveness as a true biomarker. Hydrogenation of the beta-ketone of dibutylone resulted in the most prominent metabolite found in human specimens, and its uniqueness to dibutylone over other stimulants leads to its classification as an appropriate biomarker for dibutylone ingestion. This is the first study to map the metabolic profile of dibutylone, including verification in authentic specimens, confirming metabolic conversion to butylone and identifying biomarkers more useful in forensic toxicological drug testing. [ABSTRACT FROM AUTHOR]

N -ethyl pentylone (ephylone) has been identified as the most recent novel stimulant to emerge into the arena of evolving novel psychoactive substances (NPS). Due to its novelty, information regarding case reports with associated quantitative confirmations, biotransformation pathways, and identified unique metabolites will assist the scientific community in understanding the implications of the emergence and risks associated with N -ethyl pentylone use. Authentic blood specimens (n = 26) submitted as part of toxicological death investigations or drugged driving casework tested positive for N -ethyl pentylone, and were quantitatively analyzed by liquid chromatography tandem mass spectrometry (LC–MS-MS). N -ethyl pentylone concentrations ranged from 12 to 1,200 ng/mL, with mean (±standard deviation) and median concentrations of 313 (±366) and 125 ng/mL, respectively, excluding one case measured at 50,000 ng/mL. N -ethyl pentylone was often found in combination with other drugs of abuse and NPS, include a variety of novel opioids including fentanyl analogs. Oral fluid specimens (n = 5), collected from recreational drug users at a dance music festival, were quantitatively analyzed using LC–MS-MS. Concentrations ranged from 12.6 to 1,377 ng/mL. Additional analysis was performed to characterize the metabolic profile of N -ethyl pentylone using human liver microsomes (HLM), followed by confirmation of the presence of the proposed metabolites in a subset of the blood specimens and oral fluid specimens. Metabolomic analysis was performed using a liquid chromatograph quadrupole time-of-flight mass spectrometer (LC-QTOF), followed by data processing using MetabolitePilot™ software. In vivo verification of in vitro HLM-generated metabolites resulted in the confirmation of four metabolites. Reduction of the beta-ketone to an alcohol resulted in the most prominent metabolite found in the authentic specimens, and its uniqueness to N -ethyl pentylone leads to this metabolite being an appropriate biomarker to determine N -ethyl pentylone ingestion. This is the first study to report N -ethyl pentylone concentrations and to characterize the metabolic profile of N -ethyl pentylone. [ABSTRACT FROM AUTHOR]

Renewable based materials have come out as an environmentally friendly alternative to petrochemical based materials due to their sustainability, lower carbon footprints and often lesser price. A tri-functional acrylate monomer was synthesized from Ricinoleic acid (RA) and used as biobased reactive diluent along with an oligomer for a UV curable coating application. The ricinoleic acid was modified by using sodium methoxide catalyzed amidation with diethanolamine and converted into fatty amide based triol. This synthesized ricinamide triol (RTO) was further reacted with glycidyl methacrylate in presence of triphenylphosphine. The synthesized products were fully characterized by FTIR, GPC and end group analysis. The chemical structure of RTO and ricinamide triacrylate (RTA) was elucidated from 1 H NMR, 13 C NMR spectroscopy. In comparison, the commercial triacrylate was examined. The influence of addition of reactive diluents on the viscosity of oligomer with varying concentrations up to 10–30 wt% was studied using rheometer. The UV curing behavior of coatings was estimated by FTIR. The UV cured coatings was further characterized by DSC, XRD, and TGA analysis. The UV curing coatings were evaluated to determine the mechanical, physical and solvent resistance properties. The Biobased content, gel content and water absorption property of UV cured coatings was also examined. [ABSTRACT FROM AUTHOR]

Background: Biomarker discovery studies have generated an array of omic data; however, few novel biomarkers have reached clinical use. Guidelines for rigorous study designs are needed. Content: Biases frequently occur during sample selection, outcome ascertainment, or unblinded sample handling and the assaying process. The principles of a prospective specimen collection and retrospective blinded evaluation design can be adapted to mitigate various sources of biases in discovery. We recommend establishing quality biospecimen repositories using matched 2-phase designs to minimize biases and maximize efficiency. We also highlight the importance of taking the clinical context into consideration in both sample selection and power calculation for discovery studies. Summary: Biomarker discovery research should follow rigorous design principles in sample selection to avoid biases. Consideration of clinical application and the corresponding biomarker performance characteristics in study designs will lead to a more fruitful discovery study. [ABSTRACT FROM AUTHOR]

Tissue engineering (TE) is an emerging and promising strategy to heal tissue failure by integrating science and technology of materials, cells and growth factors. With the increasing of aging population, restoring musculoskeletal tissue has become the focus of TE. Among various materials tested in TE, silk fibroin (SF) is increasingly being recognized as a promising material. SF, a natural protein polymer with excellent physiochemical characteristics, has established a good reputation in terms of musculoskeletal tissue engineering (MTE). The present article provides an overview of SF and introduces various approaches of fabricating SF-based biomaterial followed by their applications in MTE. [ABSTRACT FROM AUTHOR]

Background and objective Surface topography of biomaterials has been shown to have an effect on cells behaviour. Cell-material interactions can be visually characterized by assessing both cell shape and spreading at initial time-points and, its migration patterns, as a response to the underlying topography. Whilst many have reported the study of cell migration and shape with fluorescence labelling, the focus on evaluating cells response to surface topography is to observe, under real-time conditions, interactions between cells and surfaces. In this manuscript we present a novel approach to automatically detect and remove periodic background patterns in brightfield microscopy images in order to perform automatic cell mobility analysis. Methods The developed software, MobilityAnalyser, performs automatic tracking of unmarked cells and allows the user to manually correct any incorrectly detected or tracked cell. Human Mesenchymal Stem Cells (hMSCs) trajectory, migration distance, velocity and persistence were evaluated over line and pillar micropatterned SiO 2 films and on a flat SiO 2 control substrate. Results The developed software proved to be effective in automatically removing background patterns of both line and pillar shapes and in performing cell detection and tracking. MobilityAnalyser accurately measured cell mobility in a fraction of the time required for manual analysis and eliminated user subjectivity. The results obtained with the software confirmed how different topographies affect cell trajectory, migration pathways and velocities, with a statistically significant increase for micropatterned surfaces, when compared with the flat control. The persistence parameter also proved the influence of both patterns on the directionality of cell movement. Conclusions MobilityAnalyser is an automatic tool that removes periodic background patterns, detects and tracks cells, and provides cell mobility parameters that characterize the response of cells to different surface topographies. The software is freely available at: https://drive.google.com/open?id=1Fbb321ogLD19SlRjceMETNUqDHgpeBPl . [ABSTRACT FROM AUTHOR]

Seabird colonies drastically transform the sites that they inhabit. Although the influence of seabirds on nutrient cycling has been investigated in numerous studies, the effects on trace elements has scarcely been considered. In this study, we determined the total contents of 9 trace elements in biomaterials (excrement, pellets, feathers and eggs) and soils in relation to the presence the Yellow-legged gull Larus michahellis . The concentrations of Zn, Cu and As were particularly high in the pellets and excrement. The total contents of the trace elements were significantly higher in the soils in the sub-colonies in which Yellow-legged gulls predominate than in soil from the control zone (with no gulls). The difference was even higher for the most reactive geochemical fractions. We observed that the oxidizable fraction was the most relevant fraction for almost all trace elements, indicating the importance of organic matter in trace element retention in sandy soils. [ABSTRACT FROM AUTHOR]

Artifact-free imaging of cellulose nanofibrils (CNFs) from aqueous nanocellulose suspensions is nontrivial due to frequent irreversible agglomeration and structure damage during the course of sample preparation, especially as water is solidified prior to freeze-drying. In this study, we have examined the morphologies of CNF suspensions prepared by rapid vitrification in two different liquid cryogens—nitrogen and ethane—followed by freeze-drying. Results obtained by scanning electron microscopy confirm that vitrification in liquid ethane not only greatly improves the survivability of fine-scale CNF structural elements but also significantly reduces the propensity for CNF to agglomerate. [ABSTRACT FROM AUTHOR]

Ionic liquids are a class of solvents and materials that hold great promise in bioanalytical chemistry. Task-specific ionic liquids have recently been designed for the selective extraction, separation, and detection of proteins, peptides, nucleic acids, and other physiologically relevant analytes from complex biological samples. To facilitate rapid bioanalysis, ionic liquids have been integrated in miniaturized and automated procedures. Bioanalytical separations have also benefited from the modification of nonspecific magnetic materials with ionic liquids or the implementation of ionic liquids with inherent magnetic properties. Furthermore, the direct detection of the extracted molecules in the analytical instrument has been demonstrated with structurally tuned ionic liquids and magnetic ionic liquids, providing a significant advantage in the analysis of low-abundance analytes. This article gives an overview of these advances that involve the application of ionic liquids and derivatives in bioanalysis.Ionic liquids, magnetic ionic liquids, and ionic liquid-based sorbents are increasing the speed, selectivity, and sensitivity in the analysis of biological samples [ABSTRACT FROM AUTHOR]

Silver nanomaterials are widely used in clinically approved devices, consumer goods, and over-the-counter nutraceutical products. Despite the increase in silver nanomaterial research, few investigations have specifically distinguished the biological effects resulting from silver nanoparticles (AgNPs) versus silver ions released from AgNPs. This is in part, due to the complex analytical methods required to characterize silver ion release from AgNPs in biological media. This study sought to analyze silver ion release from AgNPs in biological media, compare silver transport from soluble AgNO 3 and AgNPs through ex vivo full thickness sinus human tissue explants and human nasal epithelium and determine fractional AgNP internalization by human nasal epithelial cells. Rapid silver ion release is observed from AgNPs in human nasal epithelial cell medium over 3 h (9.6% of total silver mass). Significantly lower translocation of AgNPs is observed through human nasal epithelial cell monolayers and ex vivo human sinus tissue explants compared to silver ion (AgNO 3 ). AgNP internalization is directly observed in AgNP-exposed human nasal epithelial cell monolayers by live cell scanning transmission electron microscopy (STEM), providing one potential mechanism for AgNP transcytosis. However, in vitro AgNP dissolution experiments suggest that silver in human nasal epithelium is primarily silver ion. Ionic AgNO 3 produces significantly higher silver translocation, supporting previous results claiming silver ion as primarily responsible for biological effects of AgNPs. [ABSTRACT FROM AUTHOR]

Laser surface structuring of biometals allows to achieve complex surface geometries at several scales since a rough surface is preferred to induce an optimal cellular response. A lack of standard measurement techniques to characterize implant surfaces was detected. This paper presents a comprehensive, multi-scale characterization of the topography of laser textured biometals with the ISO standard profile method; which allows to separate the contribution of the superimposed textures of the profile, the low frequency component (waviness) and the high frequency component (roughness), and to calculate the respective height parameters according to the standard definitions. Furthermore, the characterization was completed by the calculation of the spatial parameters obtained by FFT calculation in order to assess the horizontal characteristics of the surface. We focused on two common biometals, stainless steel 316L and titanium alloy Ti6Al4V, structured with an array of parallel grooves obtained by using a nanosecond Nd:YVO 4 laser. Regarding waviness, some differences in symmetry and sharpness were found according to the metal. Conversely, the roughness of the topography revealed that the average height of the micro-structures developed inside the grooves is similar in both metals. The spatial periodicity of the micro-structures showed that the aspect ratio resulted higher in AISI 316L than in Ti6Al4V. The analytical approach presented in this paper allows to establish an elementary comparison of the results obtained in the scientific community, contributing to a better understanding of in vitro / vivo cellular growing on textured surfaces. [ABSTRACT FROM AUTHOR]

Silk fibroin has acquired increasing interest in the last years for application in medicine and namely in tissue engineering. Several methods have been developed to process fibroin and for the fabrication of nets, sponges, films and gels. This paper deals with the fabrication and characterization of fibroin hydrogels obtained by using sodium oleate as gelation agent. Gels have been prepared by mixing Silk fibroin (SF) and Sodium oleate (SO) water solutions in different concentrations, and a quite wide frame of compositions have been explored. Rheological tests have been performed to determine the gelation times, scanning electron microscopies have been made to evaluate morphologies, FTIR analysis has been done to determine the conformation of the starting materials and of the resulting gels, water content has been measured and cytotoxicity tests have been performed to validate the potential biomedical use of the hydrogels. Depending on the SF and SO different gelation times have been obtained thanks to the formation of intermolecular bonds between the fibroin chains. The obtained fastest gelation of about 80 s could make this specific formulation compatible with in situ gelation. By changing composition, gels with different morphologies, rheological properties and water contents have been prepared. [ABSTRACT FROM AUTHOR]

Background: Biodegradable thermosensitive hydrogel scaffolds based on novel three-block PCL-PEG-PCL and penta block PNIPAAm-PCL-PEG-PCL-PNIPAAm copolymers blended with gelatin were prepared and examined on functional behavior of chondrocytes. Methods: In this work, we compared two different thermosensitive hydrogel scaffolds (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin and (PCL-PEG-PCL)/Gelatin prepared by TIPS (thermally induced phase separation) method. The feature of copolymers was characterized by FT-IR, 1H NMR. The lower critical solution temperatures (LCSTs) of aqueous solutions of copolymers were measured by cloud point (turbidity) measurements. We also examined water absorption capacity and swelling ratio. Mechanical features of the prepared hydrogels were evaluated by stress-strain measurements. Thereafter, isolated chondrocytes were cultured on each scaffold for a period of 10 days and cell arrangement and morphology studied pre-and post-plating. Cell survival assay was done by using MTT assay. The transcription level of genes Sox-9, Collagen-II, COMP, MMP-13 and oligomeric matrix protein was monitored by real-time PCR assay. The samples were also stained by Toluidine blue method to monitor the synthesis of proteoglycan. Results: Data demonstrated an increased survival rate in cells coated seeded on scaffolds, especially (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin as compared to control cells on the plastic surface. (PNIPAAm-PCL-PEG-PCL-PNIPAAm)/Gelatin had potential to increase the expression of genes Sox-6, Collagen-II, COMP and after 10 days in vitro. Conclusion: Thermosensitive PCEC/Gel and (PNIPAAm-PCEC-PNIPAAm)/Gel hydrogel scaffolds that fabricated by TIPS method possesses useful hydrophilic properties for growth and cell embedding and secretion of extracellular matrix. It can serve as an ideal strategy to promote the formation of cartilage tissue. [ABSTRACT FROM AUTHOR]

In this study, collagen/alginate/hydroxyapatite beads having different proportions were prepared as bone fillers for the restoration of osteological defects. Ionic liquid was used to dissolve the collagen and subsequently the solution was mixed with sodium alginate solution. Hydroxyapatite was added in different proportions, with the rationale to enhance mechanical as well as biological properties. The prepared solutions were given characteristic bead shapes by dropwise addition into calcium chloride solution. The prepared beads were characterized using FTIR, XRD, TGA and SEM analysis. Microhardness testing was used to evaluate the mechanical properties. The prepared beads were investigated for water adsorption behavior to ascertain its ability for body fluid uptake and adjusted accordingly to the bone cavity. Drug loading and subsequently the antibacterial activity was investigated for the prepared beads. The biocompatibility was assessed using the hemolysis testing and cell proliferation assay. The prepared collagen-alginate-HA beads, having biocompatibility and good mechanical properties, have showed an option of promising biologically active bone fillers for bone regeneration. [ABSTRACT FROM AUTHOR]

The Polycaprolactone (PCL) fibrous scaffolds in nano to micro scale have been considered as excellent templates for cell culture and tissue growth. The hydrophobic nature of the PCL, however, yields low initial cell seeding density, heterogeneous cell spreading and slow cell growth rate. Therefore, in this study the surface hydrophilic fibrous scaffolds were directly fabricated by the electrospinning of PCL solutions with small quantities (0.5-5%) of Pluronic F127 (PEO100-PPO65-PEO100) dissolved in benign solvent of glacial acetic acid. The clear and miscible solutions were achieved by controlling the proper F127 content in the blend solutions. The continuous and smooth fibers with average diameters from 0.71 to 1.43 μm made up the fibrous scaffolds in non-woven mode. Then the water wetting angle of the scaffolds could be adjusted from 126° to 0° by varying F127 content owing to its hydrophilic PEO chains presented on surface the blended fibers. Finally, it was demonstrated that the blended fibrous scaffolds with the F127 content less than 1% exhibited better cell attachment, proliferation and spreading performance than those of pure PCL scaffolds. [ABSTRACT FROM AUTHOR]

Three dimensional (3D) bioplotting requires appropriate crosslinkers to crosslink the hydrogel precursor while simultaneously maintaining the viability of embedded cells. However, the evaluation and comparison of various types of crosslinkers in bioplotting remains underexplored to date. This paper presents our study of the influence of three ionic crosslinkers—calcium chloride (CaCl2), barium chloride (BaCl2), and zinc chloride (ZnCl2)—on the mechanical and biological properties of 3D bioplotted alginate scaffolds. The scaffold mechanical properties characterized included the elastic modulus, swelling, and degradation while the biological properties considered included Schwann cell viability and surface morphology. The mechanical and biological properties of the bioplotted scaffolds were both dependent on the crosslinkers used for fabrication; specifically, crosslinking ions resulted in the elastic modulus of the hydrogels decreasing in the order BaCl2>CaCl2>ZnCl2 over 42 days while Schwann cell viability decreased in the order CaCl2>BaCl2>ZnCl2 over 7 days. Taken together, these results offer insights that are effective in terms of manipulating the 3D bioplotting process so as to tune and optimize the mechanical and biological performance of the plotted scaffolds for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Abstract: Natural creatures have evolved elaborate photonic nanostructures on multiple scales and dimensions in a hierarchical, organized way to realize controllable absorption, reflection, or transmitting the desired wavelength of the solar spectrum. A bio‐inspired strategy is a powerful and promising way for solar energy manipulation. This feature article presents the state‐of‐the‐art progress on bio‐inspired photonic materials on this particular application. The article first briefly recalls the physical origins of natural photonic effects and catalogues the typical natural photonic prototypes including light harvesting, broadband reflection, selective reflection, and UV/IR response. Next, typical applications are categorized into two primary areas: solar energy utilization and reflection. Recent advances including solar‐to‐electricity, solar‐to‐fuels, solar‐thermal (e.g., photothermal converters, infrared detectors, thermoelectric materials, smart windows, and solar steam generation) are highlighted in the first part. Meanwhile, solar energy reflection involving infrared stealth, radiative cooling, and micromirrors are also addressed. In particular, this article focuses on bioinspired design principles, structural effects on functions, and future trends. Finally, the main challenges and prospects for the next generation of bioinspired photonic materials are discussed, including new design concepts, emerging ideas, and possible strategies. [ABSTRACT FROM AUTHOR]

Abstract: Optical techniques used in medical diagnosis, surgery, and therapy require efficient and flexible delivery of light from light sources to target tissues. While this need is currently fulfilled by glass and plastic optical fibers, recent emergence of biointegrated approaches, such as optogenetics and implanted devices, calls for novel waveguides with certain biophysical and biocompatible properties and desirable shapes beyond what the conventional optical fibers can offer. To this end, exploratory efforts have begun to harness various transparent biomaterials to develop waveguides that can serve existing applications better and enable new applications in future photomedicine. Here, the recent progress in this new area of research for developing biomaterial‐based optical waveguides is reviewed. It begins with a survey of biological light‐guiding structures found in plants and animals, a source of inspiration for biomaterial photonics engineering. The review then describes natural and synthetic polymers and hydrogels that offer appropriate optical properties, biocompatibility, biodegradability, and mechanical flexibility have been exploited for light‐guiding applications. Finally, perspectives on biomedical applications that may benefit from the unique properties and functionalities of light‐guiding biomaterials are discussed briefly. [ABSTRACT FROM AUTHOR]