Deep learning for in vivo near-infrared imaging.

Detecting fluorescence in the second near-infrared window (NIR-II) up to ∼1,700 nm has emerged as a novel in vivo imaging modality with high spatial and temporal resolution through millimeter tissue depths. Imaging in the NIR-IIb window (1,500-1,700 nm) is the most effective one-photon approach to suppressing light scattering and maximizing imaging penetration depth, but relies on nanoparticle probes such as PbS/CdS containing toxic elements. On the other hand, imaging the NIR-I (700-1,000 nm) or NIR-IIa window (1,000-1,300 nm) can be done using biocompatible small-molecule fluorescent probes including US Food and Drug Administration-approved dyes such as indocyanine green (ICG), but has a caveat of suboptimal imaging quality due to light scattering. It is highly desired to achieve the performance of NIR-IIb imaging using molecular probes approved for human use. Here, we trained artificial neural networks to transform a fluorescence image in the shorter-wavelength NIR window of 900-1,300 nm (NIR-I/IIa) to an image resembling an NIR-IIb image. With deep-learning translation, in vivo lymph node imaging with ICG achieved an unprecedented signal-to-background ratio of >100. Using preclinical fluorophores such as IRDye-800, translation of ∼900-nm NIR molecular imaging of PD-L1 or EGFR greatly enhanced tumor-to-normal tissue ratio up to ∼20 from ∼5 and improved tumor margin localization. Further, deep learning greatly improved in vivo noninvasive NIR-II light-sheet microscopy (LSM) in resolution and signal/background. NIR imaging equipped with deep learning could facilitate basic biomedical research and empower clinical diagnostics and imaging-guided surgery in the clinic.

In vivo NIR-II structured-illumination light-sheet microscopy.

Noninvasive optical imaging with deep tissue penetration depth and high spatiotemporal resolution is important to longitudinally studying the biology at the single-cell level in live mammals, but has been challenging due to light scattering. Here, we developed near-infrared II (NIR-II) (1,000 to 1,700 nm) structured-illumination light-sheet microscopy (NIR-II SIM) with ultralong excitation and emission wavelengths up to ∼1,540 and ∼1,700 nm, respectively, suppressing light scattering to afford large volumetric three-dimensional (3D) imaging of tissues with deep-axial penetration depths. Integrating structured illumination into NIR-II light-sheet microscopy further diminished background and improved spatial resolution by approximately twofold. In vivo oblique NIR-II SIM was performed noninvasively for 3D volumetric multiplexed molecular imaging of the CT26 tumor microenvironment in mice, longitudinally mapping out CD4, CD8, and OX40 at the single-cell level in response to immunotherapy by cytosine-phosphate-guanine (CpG), a Toll-like receptor 9 (TLR-9) agonist combined with OX40 antibody treatment. NIR-II SIM affords an additional tool for noninvasive volumetric molecular imaging of immune cells in live mammals.

Light-sheet microscopy in the near-infrared II window.

Non-invasive deep-tissue three-dimensional optical imaging of live mammals with high spatiotemporal resolution is challenging owing to light scattering. We developed near-infrared II (1,000-1,700 nm) light-sheet microscopy with excitation and emission of up to approximately 1,320 nm and 1,700 nm, respectively, for optical sectioning at a penetration depth of approximately 750 µm through live tissues without invasive surgery and at a depth of approximately 2 mm in glycerol-cleared brain tissues. Near-infrared II light-sheet microscopy in normal and oblique configurations enabled in vivo imaging of live mice through intact tissue, revealing abnormal blood flow and T-cell motion in tumor microcirculation and mapping out programmed-death ligand 1 and programmed cell death protein 1 in tumors with cellular resolution. Three-dimensional imaging through the intact mouse head resolved vascular channels between the skull and brain cortex, and allowed monitoring of recruitment of macrophages and microglia to the traumatic brain injury site.

Optically Triggering and Monitoring Single-Cell-Level Metabolism Using Ormosil-Decorated Ultrathin Fibers.

The integration of biological components and artificial devices requires a bio-machine interface that can simultaneously trigger and monitor the activities in biosystems. Herein, we use an organically modified silicate (ormosil) composite coating containing a light-responsive nanocapsule and a fluorescent bioprobe for reactive oxygen species (ROS) to decorate ultrathin optical fibers, namely, ormosil-decorated ultrathin fibers (OD-UFs), and demonstrate that these OD-UFs can optically trigger and monitor the intracellular metabolism activities in living cells. The sizes and shapes of UF tips were finely controlled to match the dimension and mechanical properties of living cells. The increased elasticity of the ormosil coating of OD-UFs reduces possible mechanical damage during the cell membrane penetration. The light-responsive nanocapsule was physically absorbed on the surface of the ormosil coating and could release a stimulant to trigger the metabolism activities in cells upon the guided laser through OD-UFs. The fluorescent bioprobe was covalently linked with the ormosil matrix for monitoring the intracellular ROS generation, which was verified by the in vitro experiments on the microdroplets of a hydrogen peroxide solution. Finally, we found that the living cells could maintain most of their viability after being inserted with OD-UFs, and the intracellular metabolism activities were successfully triggered and monitored at the single-cell level. The OD-UF provides a new platform for the investigation of intracellular behaviors for drug stimulations and represents a new proof of concept for a bio-machine interface based on the optical and chemical activities of organic functional molecules.

A mini-review on peptide-based self-assemblies and their biological applications.

Peptide-based supramolecular self-assembly from peptide monomers into well-organized nanostructures, has attracted extensive attentions towards biomedical and biotechnological applications in recent decades. This spontaneous and reversible assembly process involving non-covalent bonding interactions can be artificially regulated. In this review, we have elaborated different strategies to modulate the peptide self-assembly through tuning the physicochemical and environmental conditions, includingpH, light, temperature, solvent, and enzyme. Detailed introduction of biological applications and future potential of the peptide-based nano-assemblies will also be given.

Diagnostic value of interferon-γ release assay in HIV-infected individuals complicated with active tuberculosis: a systematic review and meta-analysis.

OBJECTIVE: Although the interferon-γ release assay (IGRA) has become a common diagnostic method for tuberculosis, its value in the diagnosis of tuberculosis in human immunodeficiency virus (HIV) seropositive patients remains controversial. Therefore, this systematically reviews the data for exploring the diagnostic value of IGRA in HIV-infected individuals complicated with active tuberculosis, aiming to provide a clinical basis for future clinical diagnosis of the disease. METHODS: Relevant studies on IGRA for diagnosing tuberculosis in HIV-infected patients were comprehensively collected from Excerpta Medica Database (EMBASE), Medline, Cochrane Library, Chinese Sci-tech Periodical Full-text Database, Chinese Periodical Full-text Database, China National Knowledge Infrastructure (CNKI) and China Wanfang Data up to July 2020. Subsequently, Stata 15.0, an integrated statistical software, was used to analyse the sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR) and negative likelihood ratio (NLR) to create receiver operator characteristic (ROC) curves. RESULTS: A total of 18 high-quality articles were selected, including 20 studies, 11 of which were related to QuantiFERON-TB Gold In-Tube (QFT-GIT) and nine to T-SPOT.TB. The meta-analysis indicated that the pooled sensitivity = 0.75 (95% CI 0.63-0.85), the pooled specificity = 0.82 (95% CI 0.66-0.92), PLR = 4.25 (95% CI 1.97-9.18), NLR = 0.30 (95% CI 0.18-0.50), DOR = 14.21 (95% CI 4.38-46.09) and the area under summary ROC curve was 0.85 (95% CI 0.81-0.88). CONCLUSION: IGRA has a good diagnostic value and therefore can aid in the preliminary screening of active tuberculosis in HIV-infected individuals. Its diagnostic effectiveness can be improved by modifying and optimizing the assay design.

Bright quantum dots emitting at ∼1,600 nm in the NIR-IIb window for deep tissue fluorescence imaging.

With suppressed photon scattering and diminished autofluorescence, in vivo fluorescence imaging in the 1,500- to 1,700-nm range of the near-IR (NIR) spectrum (NIR-IIb window) can afford high clarity and deep tissue penetration. However, there has been a lack of NIR-IIb fluorescent probes with sufficient brightness and aqueous stability. Here, we present a bright fluorescent probe emitting at ∼1,600 nm based on core/shell lead sulfide/cadmium sulfide (CdS) quantum dots (CSQDs) synthesized in organic phase. The CdS shell plays a critical role of protecting the lead sulfide (PbS) core from oxidation and retaining its bright fluorescence through the process of amphiphilic polymer coating and transferring to water needed for imparting aqueous stability and compatibility. The resulting CSQDs with a branched PEG outer layer exhibited a long blood circulation half-life of 7 hours and enabled through-skin, real-time imaging of blood flows in mouse vasculatures at an unprecedented 60 frames per second (fps) speed by detecting ∼1,600-nm fluorescence under 808-nm excitation. It also allowed through-skin in vivo confocal 3D imaging of tumor vasculatures in mice with an imaging depth of ∼1.2 mm. The PEG-CSQDs accumulated in tumor effectively through the enhanced permeation and retention effect, affording a high tumor-to-normal tissue ratio up to ∼32 owing to the bright ∼1,600-nm emission and nearly zero autofluorescence background resulting from a large ∼800-nm Stoke's shift. The aqueous-compatible CSQDs are excreted through the biliary pathway without causing obvious toxicity effects, suggesting a useful class of ∼1,600-nm emitting probes for biomedical research.

Miniature Hollow Gold Nanorods with Enhanced Effect for In Vivo Photoacoustic Imaging in the NIR-II Window.

The miniaturization of gold nanorods exhibits a bright prospect for intravital photoacoustic imaging (PAI) and the hollow structure possesses a better plasmonic property. Herein, miniature hollow gold nanorods (M-AuHNRs) (≈46 nm in length) possessing strong plasmonic absorbance in the second near-infrared (NIR-II) window (1000-1350 nm) are developed, which are considered as the most suitable range for the intravital PAI. The as-prepared M-AuHNRs exhibit 3.5 times stronger photoacoustic signal intensity than the large hollow Au nanorods (≈105 nm in length) at 0.2 optical density under 1064 nm laser irradiation. The in vivo biodistribution measurement shows that the accumulation in tumor of miniature nanorods is twofold as high as that of the large counterpart. After modifying with a tumor-targeting molecule and fluorochrome, in living tumor-bearing mice, the M-AuHNRs group gives a high fluorescence intensity in tumors, which is 3.6-fold that of the large ones with the same functionalization. Moreover, in the intravital PAI of living tumor-bearing mice, the M-AuHNRs generate longer-lasting and stronger photoacoustic signal than the large counterpart in the NIR-II window. Overall, this study presents the fabrication of M-AuHNRs as a promising contrast agent for intravital PAI.

Molecular imaging of biological systems with a clickable dye in the broad 800- to 1,700-nm near-infrared window.

Fluorescence imaging multiplicity of biological systems is an area of intense focus, currently limited to fluorescence channels in the visible and first near-infrared (NIR-I; ∼700-900 nm) spectral regions. The development of conjugatable fluorophores with longer wavelength emission is highly desired to afford more targeting channels, reduce background autofluorescence, and achieve deeper tissue imaging depths. We have developed NIR-II (1,000-1,700 nm) molecular imaging agents with a bright NIR-II fluorophore through high-efficiency click chemistry to specific molecular antibodies. Relying on buoyant density differences during density gradient ultracentrifugation separations, highly pure NIR-II fluorophore-antibody conjugates emitting ∼1,100 nm were obtained for use as molecular-specific NIR-II probes. This facilitated 3D staining of ∼170-µm histological brain tissues sections on a home-built confocal microscope, demonstrating multicolor molecular imaging across both the NIR-I and NIR-II windows (800-1,700 nm).

Cross-Link-Functionalized Nanoparticles for Rapid Excretion in Nanotheranostic Applications.

Most NIR-IIb fluorophores are nanoparticle-based probes with long retention (≈1 month or longer) in the body. Here, we applied a novel cross-linked coating to functionalize core/shell lead sulfide/cadmium sulfide quantum dots (PbS/CdS QDs) emitting at ≈1600 nm. The coating was comprised of an amphiphilic polymer followed by three crosslinked amphiphilic polymeric layers (P3 coating), imparting high biocompatibility and >90 % excretion of QDs within 2 weeks of intravenous administration. The P3 -QDs were conjugated to an engineered anti-CD8 diabody (Cys-diabody) for in vivo molecular imaging of CD8+ cytotoxic T lymphocytes (CTLs) in response to anti-PD-L1 therapy. Two-plex molecular imaging in combination with down-conversion Er nanoparticles (ErNPs) was performed for real-time in vivo monitoring of PD-L1 positive tumor cells and CTLs with cellular resolution by non-invasive NIR-IIb light sheet microscopy. Imaging of angiogenesis in the tumor microenvironment and of lymph nodes deep in the body with a signal-to-background ratio of up to ≈170 was also achieved using P3 -QDs.

High incidence of drug-resistant Mycobacterium tuberculosis in Hainan Island, China.

OBJECTIVES: To assess the proportion of drug-resistant tuberculosis (TB) cases and to identify independent risk factors associated with drug-resistant TB in Hainan. METHODS: Descriptive analysis of demographic and clinical data of culture-positive TB patients to assess the trends in drug-resistant TB at the Provincial Clinical Center on Tuberculosis of Hainan between 2014 and 2017. RESULTS: 994 patients were recruited into the study. Overall, the proportion of patients resistant to at least one TB drug tested was 36.1% (359/994). The most frequent resistance was to isoniazid (INH, 29.8%), followed by rifampin (RIF, 29.3%), streptomycin (19.3%), ofloxacin (OFX, 17.4%), ethambutol (9.5%) and kanamycin (KAN, 3.2%). Of 291 RIF-resistant isolates, 228 (78.4%) were also resistant to INH, while the remaining 63 (21.6%) were susceptible to INH. Among those with multidrug-resistant tuberculosis (MDR-TB), 41.2% had additional resistance to OFX and 3.9% to KAN. 8.8% of MDR-TB patients were affected by extensively drug-resistant (XDR-TB). Females were more likely to infected with MDR-TB than males, and young people (<20 years old) were more likely to have MDR-TB; patients exhibited decreasing MDR-TB risk with increasing age. CONCLUSIONS: Our data provide the first primary understanding of the drug-resistant TB epidemic in Hainan. The high incidence of drug resistance, especially RIF and FQ resistance, highlight the importance of interventions for preventing epidemics of drug-resistant TB. Younger age is an independent predictor of MDR-TB, reflecting the potential transmission in this population.

OBJECTIFS: Evaluer la proportion de cas de tuberculose (TB) résistante aux médicaments et identifier les facteurs de risque indépendants associés à la TB résistante à Hainan. MÉTHODES: Analyse descriptive des données démographiques et cliniques de patients TB à culture positive pour évaluer les tendances de la TB résistante au Centre Clinique Provincial de la TB de Hainan entre 2014 et 2017. RÉSULTATS: 994 patients ont été recrutés dans l'étude. Au total, la proportion de patients résistant à au moins un antituberculeux testé était de 36,1% (359/994). La résistance la plus fréquente était à l'isoniazide (INH, 29,8%), suivi par la rifampine (RIF, 29,3%), la streptomycine (19,3%), l'ofloxacine (OFX, 17,4%), l'éthambutol (9,5%) et la kanamycine (KAN, 3,2%). Sur les 291 isolats résistants au RIF, 228 (78,4%) étaient également résistants à l'INH, tandis que les 63 restants (21,6%) étaient sensibles à l'INH. Parmi ceux avec la multirésistance (TB-MDR), 41,2% présentaient une résistance supplémentaire à l'OFX et 3,9% à la KAN. 8,8% des patients atteints de TB-MDR étaient atteints d'une TB ultrarésistante (TB-XDR). Les femmes étaient plus susceptibles d'être infectées par la TB-MDR que les hommes et les jeunes (<20 ans) étaient plus susceptibles d'être atteints de TB-MDR; les patients présentaient un risque décroissant de TB-MDR avec l'âge. CONCLUSIONS: Nos données fournissent la première compréhension importante de l'épidémie de TB résistante à Hainan. L'incidence élevée de la résistance aux médicaments, en particulier des résistances RIF et FQ, souligne l'importance des interventions pour prévenir les épidémies de TB résistante. L'âge plus jeune est un facteur indépendant de prédiction de la TB-MDR, reflétant le potentiel de transmission dans cette population.

Near-Infrared IIb Fluorescence Imaging of Vascular Regeneration with Dynamic Tissue Perfusion Measurement and High Spatial Resolution.

Real-time optical imaging is a promising approach for visualizing in vivo hemodynamics and vascular structure in mice with experimentally induced peripheral arterial disease (PAD). We report the application of a novel fluorescence-based all-optical imaging approach in the near-infrared IIb (NIR-IIb, 1500-1700 nm emission) window, for imaging hindlimb microvasculature and blood perfusion in a mouse model of PAD. In phantom studies, lead sulfide/cadmium sulfide (PbS/CdS) quantum dots showed better retention of image clarity, in comparison with single-walled nanotube (SWNT) NIR-IIa (1000-1400nm) dye, at varying depths of penetration. When systemically injected to mice, PbS/CdS demonstrated improved clarity of the vasculature, compared to SWNTs, as well as higher spatial resolution than in vivo microscopic computed tomography. In a mouse model of PAD, NIR-IIb imaging of the ischemic hindlimb vasculature showed significant improvement in blood perfusion over the course of 10 days (P<0.05), as well as a significant increase in microvascular density over the first 7 days after induction of PAD. In conclusion, NIR-IIb imaging of PbS/CdS vascular contrast agent is a useful multi-functional imaging approach for high spatial resolution imaging of the microvasculature and quantification of blood perfusion recovery.

Developing a Bright NIR-II Fluorophore with Fast Renal Excretion and Its Application in Molecular Imaging of Immune Checkpoint PD-L1.

Fluorescence imaging in the second near-infrared (NIR-II) window holds impressive advantages of enhanced penetration depth and improved signal-to-noise ratio. Bright NIR-II fluorophores with renal excretion ability and low tissue accumulation are favorable for in vivo molecular imaging applications as they can render the target-mediated molecular imaging process easily distinguishable. Here, a probe (anti-PD-L1-BGP6) comprising a fluorophore (IR-BGP6) covalently bonded to the programmed cell death ligand-1 monoclonal antibody (PD-L1 mAb) for molecular imaging of immune checkpoint PD-L1 (a targeting site upregulated in various tumors for cancer imaging) in the NIR-II window is reported. Through molecular optimization, the bright NIR-II fluorophore IR-BGP6 with fast renal excretion (≈91% excretion in general through urine within the first 10 h postinjection) is developed. The conjugate anti-PD-L1-BGP6 succeeds in profiling PD-L1 expression and realizes efficient noninvasive molecular imaging in vivo, achieving a tumor to normal tissue (T/NT) signal ratio as high as ≈9.5. Compared with the NIR-II fluorophore with high nonspecific tissue accumulation, IR-BGP6 derived PD-L1 imaging significantly enhances the molecular imaging performance, serving as a strong tool for potentially studying underlying mechanism of immunotherapy. The work provides rationales to design renal-excreted NIR-II fluorophores and illustrate their advantages for in vivo molecular imaging.

Oxyhaemoglobin saturation NIR-IIb imaging for assessing cancer metabolism and predicting the response to immunotherapy.

In vivo quantitative assessment of oxyhaemoglobin saturation (sO2) status in tumour-associated vessels could provide insights into cancer metabolism and behaviour. Here we develop a non-invasive in vivo sO2 imaging technique to visualize the sO2 levels of healthy and tumour tissue based on photoluminescence bioimaging in the near-infrared IIb (NIR-IIb; 1,500-1,700 nm) window. Real-time dynamic sO2 imaging with a high frame rate (33 Hz) reveals the cerebral arteries and veins through intact mouse scalp/skull, and this imaging is consistent with the haemodynamic analysis results. Utilizing our non-invasive sO2 imaging, the tumour-associated-vessel sO2 levels of various cancer models are evaluated. A positive correlation between the tumour-associated-vessel sO2 levels and the basal oxygen consumption rate of corresponding cancer cells at the early stages of tumorigenesis suggests that cancer cells modulate the tumour metabolic microenvironment. We also find that a positive therapeutic response to the checkpoint blockade cancer immunotherapy could lead to a dramatic decrease of the tumour-associated-vessel sO2 levels. Two-plex dynamic NIR-IIb imaging can be used to simultaneously observe tumour-vessel sO2 and PD-L1, allowing a more accurate prediction of immunotherapy response.

Synthesis and properties of oval-shaped iron oxide/ethylene glycol mesostructured nanosheets.

We have demonstrated a new and facile bottom-up protocol for the effective synthesis of oval-shaped iron oxide/ethylene glycol (FeOx /EG) mesostructured nanosheets. Deprotonated ethylene glycol molecules are intercalated into iron oxide layers to form an interlayer distance of 10.6 Å. These materials display some peculiar magnetic properties, such as the low Morin temperature T(M) and ferromagnetism below this T(M) value. CdSe/ZnS nanoparticles can be loaded onto these mesostructured nanosheets to produce nanocomposites that combine both magnetic and fluorescence functions. In addition, iron oxide/propanediol (or butanediol) mesostructured materials with increased interlayer distances can also be synthesized. The developed synthetic strategy may be extended toward the creation of other ultrathin mesostructured nanosheets.

Screening and Drug Resistance Analysis of Non-Tuberculous Mycobacteria in Patients with Suspected Pulmonary Tuberculosis on the Hainan Island, China.

Background: China has seen a drastic increase in the incidence of non-tuberculous mycobacteria (NTM) infection, which is a notable public health issue. Due to a lack of reliable epidemiological surveillance information, there is a need to gather accurate epidemiological and surveillance data, which can help clinicians effectively treat NTM patients. Moreover, drug susceptibility testing for NTM is not frequently performed in China. This retrospective study, therefore, determined the prevalence and resistance characteristics of NTM to provide a reference to control the NTM epidemic. Methods: Sputum, alveolar lavage fluid, and other respiratory specimens were collected from 3025 patients with suspected pulmonary tuberculosis attending The Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2021. Strain identification and species distribution of NTM were performed by DNA chip technology and gene sequencing, and the drug resistance of NTM isolates was evaluated by calculating the minimum inhibitory concentration through antimicrobial susceptibility testing for NTM. Results: From 2014 to 2021, 373 strains of NTM were isolated and identified from respiratory specimens of 3025 suspected tuberculosis patients. Except in 2014, NTM-infected patients accounted for more than 10% of suspected tuberculosis patients in other years. The median age of patients with NTM infection was 62.0 years (53.0, 71.0), and the male-to-female ratio among these patients was 0.79:1. Among culture-positive strains, 12.3% (373/3040; 95% CI 11.1-13.4%) were identified as NTM comprising forty species of NTM. The forty species of NTM included 23 slow-growing mycobacteria (SGM) and 17 rapidly-growing mycobacteria (RGM). Among the NTM isolates, 58.7% (219/373; 95% CI 53.7-63.7%) were SGM and 41.3% (154/373; 95% CI 36.3-46.3%) were RGM. M.avium complex(MAC)(41.3%; 95% CI 36.3-46.3%) and M.abscessus complex (MABC)(33.2%; 95% CI 28.4-38.0%) were the most frequently detected species, followed by M.simiae Complex (11.8%; 95% CI 8.5-15.1%), M.fortuitum group (5.1%; 95% CI 2.9-7.3%), and others. Drug sensitivity test results showed that most of the NTM isolates were susceptible to amikacin and clarithromycin with a drug resistance rate of less than 10%. However, clarithromycin could induce drug resistance, followed by linezolid and moxifloxacin, and their drug resistance rate was less than 50%. Conclusion: During 2014-2021, the number of NTM isolates detected in the respiratory specimens of the study patients in The Second Affiliated Hospital of Hainan Medical University increased year by year. M. intracellulare is the most common pathogenic NTM species, and there is a high incidence of NTM infection on Hainan Island. Our findings might be of great importance for diagnosing and treating this patient population in Hainan.

Analysis of Drug-Resistance Characteristics and Genetic Diversity of Multidrug-Resistant Tuberculosis Based on Whole-Genome Sequencing on the Hainan Island, China.

Purpose: Given the high burden of Tuberculosis (TB) in China, the prevalence of multidrug-resistant tuberculosis (MDR-TB) is significant. Whole-genome sequencing (WGS) of Mycobacterium tuberculosis (MTB) enables the identification of lineages, drug-resistant mutations, and transmission patterns, offering valuable insights for TB control, clinical diagnosis, and treatment. Methods: We collected 202 MDR-MTB strains from 3519 suspected pulmonary TB patients treated at The Second Affiliated Hospital of Hainan Medical University between July 2019 and June 2021. Proportional drug-susceptibility testing was performed using 8 common anti-tuberculosis drugs. Subsequently, the genotypic drug resistance and genetic characteristics were analyzed by the WGS. Results: Lineages are identified by TB-profiler revealed 202 MDR-MTB strains, showcasing three predominant lineages, with lineage 2 being the most prevalent. Close genomic relatedness analysis and evidence of MTB transmission led to the formation of 15 clusters comprising 42 isolates, resulting in a clustering rate of 20.8%. Novelty, lineage 2.1 (non-Beijing) accounted for 27.2% of the MDR-MTB strains, which is rare in China and Neighboring countries. Regarding first-line anti-TB drugs, genes associated with rifampicin resistance, primarily the rpoB gene, were detected in 200 strains (99.0%). Genes conferring resistance to isoniazid, ethambutol, and streptomycin were identified in 191 (94.5%), 125 (61.9%), and 100 (49.5%) strains, respectively. Among the second-line drugs, 97 (48.0%) strains exhibited genes encoding resistance to fluoroquinolones. Comparing the results to phenotypic drug susceptibility-based testing, the sensitivity of WGS for detecting resistance to each of the six drugs (rifampicin, isoniazid, ethambutol, ofloxacin, kanamycin, capreomycin) was 90% or higher. With the exception of ethambutol, the specificity of WGS prediction for the remaining drugs exceeded 88%. Conclusion: Our study provides crucial insights into genetic mutation types, genetic diversity, and transmission of MDR-MTB on Hainan Island, serving as a significant reference for MDR-MTB surveillance and clinical decision-making.

DNA self-assembly nanoflower reverse P-glycoprotein mediated drug resistance in chronic myelogenous leukemia therapy.

Introduction: Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disorder caused by the BCR-ABL chimeric tyrosine kinase. Vincristine (VCR) is widely used in leukemia therapy but is hindered by multidrug resistance (MDR). Methods: We prepared DNA nanoflower via self-assembly for the delivery of VCR and P-glycoprotein small interfering RNA (P-gp siRNA). Results and Discussion: The as-prepared nanoflower had a floriform shape with high loading efficiency of VCR (80%). Furthermore, the nanoflower could deliver VCR and P-gp siRNA into MDR CML cells and induce potent cytotoxicity both in vitro and in vivo, thus overcoming MDR of CML. Overall, this nanoflower is a promising tool for resistant CML therapy.

Shortwave-infrared-light-emitting probes for the in vivo tracking of cancer vaccines and the elicited immune responses.

Tracking and imaging immune cells in vivo non-invasively would offer insights into the immune responses induced by vaccination. Here we report a cancer vaccine consisting of polymer-coated NaErF4/NaYF4 core-shell down-conversion nanoparticles emitting luminescence in the near-infrared spectral window IIb (1,500-1,700 nm in wavelength) and with surface-conjugated antigen (ovalbumin) and electrostatically complexed adjuvant (class-B cytosine-phosphate-guanine). Whole-body wide-field imaging of the subcutaneously injected vaccine in tumour-bearing mice revealed rapid migration of the nanoparticles to lymph nodes through lymphatic vessels, with two doses of the vaccine leading to the complete eradication of pre-existing tumours and to the prophylactic inhibition of tumour growth. The abundance of antigen-specific CD8+ T lymphocytes in the tumour microenvironment correlated with vaccine efficacy, as we show via continuous-wave imaging and lifetime imaging of two intravenously injected near-infrared-emitting probes (CD8+-T-cell-targeted NaYbF4/NaYF4 nanoparticles and H-2Kb/ovalbumin257-264 tetramer/PbS/CdS quantum dots) excited at different wavelengths, and by volumetrically visualizing the three nanoparticles via light-sheet microscopy with structured illumination. Nanoparticle-based vaccines and imaging probes emitting infrared light may facilitate the design and optimization of immunotherapies.

One-pot size and interior-cavity controlled synthesis of ZnO hollow micro-/nano-structured spheres.

In this work, ZnO hollow micro-/nano-structured microspheres were prepared via a one-pot solution route. The size and interior-cavity of these microspheres could be easily controlled by varying the precursor concentration. The hollow spherical assemblies were composed of short rod-like building units at low precursor concentration. When the precursor concentration increased, one-dimensional (1D) "pearl-chain-like" building units formed firstly and then self organized into hollow microspheres. The organization process and ripening of "pearl-chain-like" building units could be modulated by simply altering the reaction time. When tested in photocatalytic experiments, the hollow microspheres composed of loosely packed 1D "pearl-chain-like" building units showed higher activity than the densely packed ones. This method is very simple, mild, and may provide a new strategy to synthesize hierarchical self-assembled hollow structures.