Spin Unlocked Vortex Beam Generation on Nonlinear Chiroptical Metasurfaces.

Optical vortices with spin and orbital angular momentum (SAM and OAM) states offer multiple degrees of freedom for manipulating optical fields and thus enable great potentials in optical information processing. Recently, the optical metasurface has become an important platform for vortex beam generation and steering. However, the strong spin-orbit interaction on such metasurfaces usually leads to spin locked OAM generation, which limits the complete control of the angular momentum state of light. Here, we propose to solve this constraint using geometric phase controlled nonlinear chiroptical metasurfaces. The metasurface consists of two types of plasmonic meta-atoms which have opposite handedness and exhibit a strong spin-dependent circular dichroism effect. By encoding specific phase singularities and phase gradients to different channels, we experimentally demonstrate the spin unlocked second harmonic beam steering. The proposed nonlinear chiroptical metasurfaces may have important applications in developing multifunctional nonlinear optical devices.

Hollow CoFe Nanozymes Integrated with Oncolytic Peptides Designed via Machine-Learning for Tumor Therapy.

Developing novel substances to synergize with nanozymes is a challenging yet indispensable task to enable the nanozyme-based therapeutics to tackle individual variations in tumor physicochemical properties. The advancement of machine learning (ML) has provided a useful tool to enhance the accuracy and efficiency in developing synergistic substances. In this study, ML models to mine low-cytotoxicity oncolytic peptides are applied. The filtering Pipeline is constructed using a traversal design and the Autogluon framework. Through the Pipeline, 37 novel peptides with high oncolytic activity against cancer cells and low cytotoxicity to normal cells are identified from a library of 25,740 sequences. Combining dataset testing with cytotoxicity experiments, an 80% accuracy rate is achieved, verifying the reliability of ML predictions. Peptide C2 is proven to possess membranolytic functions specifically for tumor cells as targeted by Pipeline. Then Peptide C2 with CoFe hollow hydroxide nanozyme (H-CF) to form the peptide/H-CF composite is integrated. The new composite exhibited acid-triggered membranolytic function and potent peroxidase-like (POD-like) activity, which induce ferroptosis to tumor cells and inhibits tumor growth. The study suggests that this novel ML-assisted design approach can offer an accurate and efficient paradigm for developing both oncolytic peptides and synergistic peptides for catalytic materials.

Small noncoding RNA discovery and profiling with sRNAtools based on high-throughput sequencing.

Small noncoding RNAs (sRNA/sncRNAs) are generated from different genomic loci and play important roles in biological processes, such as cell proliferation and the regulation of gene expression. Next-generation sequencing (NGS) has provided an unprecedented opportunity to discover and quantify diverse kinds of sncRNA, such as tRFs (tRNA-derived small RNA fragments), phasiRNAs (phased, secondary, small-interfering RNAs), Piwi-interacting RNA (piRNAs) and plant-specific 24-nt short interfering RNAs (siRNAs). However, currently available web-based tools do not provide approaches to comprehensively analyze all of these diverse sncRNAs. This study presents a novel integrated platform, sRNAtools (https://bioinformatics.caf.ac.cn/sRNAtools), that can be used in conjunction with high-throughput sequencing to identify and functionally annotate sncRNAs, including profiling microRNAss, piRNAs, tRNAs, small nuclear RNAs, small nucleolar RNAs and rRNAs and discovering isomiRs, tRFs, phasiRNAs and plant-specific 24-nt siRNAs for up to 21 model organisms. Different modules, including single case, batch case, group case and target case, are developed to provide users with flexible ways of studying sncRNA. In addition, sRNAtools supports different ways of uploading small RNA sequencing data in a very interactive queue system, while local versions based on the program package/Docker/virtureBox are also available. We believe that sRNAtools will greatly benefit the scientific community as an integrated tool for studying sncRNAs.

Gradient-assisted metasurface absorber with dual-band chiral switching and quasi-linearly tunable circular dichroism.

Chiral metasurfaces with tunable or switchable circular dichroism (CD) responses hold great potential for advanced optical devices. In this work, we theoretically propose and numerically demonstrate a chiral metasurface absorber composed of periodically serrated Ge2Sb2Te5 (GST) resonators. By harnessing strong plasmonic resonance using the gradient geometry, we achieve a strongly enhanced chiral response with a CD value of 0.98 at λ2 = 2359 nm and a CD value of 0.7 at λ1 = 2274 nm. Additionally, by controlling the gradient difference in the serrated GST resonator, we can modify the CD intensity in multiple dimensions and near-perfectly optimize the chiral properties. Furthermore, it is worth noting that the CD value can be strongly varied by adjusting the phase transition characteristics of GST in the range of 0.007 to 0.7 at λ1 and 0.002 to 0.98 at λ2, corresponding to a switch between "on" and "off" states. The findings give new insight into multi-functional chiroptics and hold wide applications.

A bifunctional bortezomib-loaded porous nano-hydroxyapatite/alginate scaffold for simultaneous tumor inhibition and bone regeneration.

Treatments of osteolytic lesions due to malignant metastasis remain one of the major clinical challenges. The residual tumor cells after surgical resections and an acidic tumor microenvironment are unfavorable for osteogenic induction. Bortezomib (BTZ), a proteasome inhibitor used in chemotherapy, also has an osteogenic potential in concentration- and Ca2+-dependent manners. In this study, controlled delivery of BTZ in a novel bifunctional scaffold based on nano-hydroxyapatite (nHA) and sodium alginate (SA) nanocomposite, namely BTZ/nHA@SA, has been explored. By smartly adjusting microenvironments, a sustainable release of Ca2+ from nHA could be achieved, which was not only able to cross-link SA but also to regulate the switch between the dual functions of tumor inhibition and bone regeneration of BTZ to promote the osteogenic pathway. The freeze-dried BTZ/nHA@SA scaffold has excellent interconnectivity, is capable to promote the attachment and proliferation of mouse embryonic osteoblast precursor cells, as well as effectively induces breast cancer cell death in vitro. Furthermore, in vivo, studies using a mouse tumor model and a rabbit femoral defect model showed that the BTZ/nHA@SA scaffold could promote tumor ablation, and also enhance bone repair. Therefore, the BTZ/nHA@SA scaffold has unique dual functions of inhibiting tumor recurrence and promoting bone tissue regeneration simultaneously. This smart bi-functional scaffold offers a promising novel approach for oncological treatments by synchronously orchestrating tumor inhibition and tissue regeneration for the repair of neoplastic bone defects.

What Matters in Radiological Image Segmentation? Effect of Segmentation Errors on the Diagnostic Related Features.

Segmentation is a crucial step in extracting the medical image features for clinical diagnosis. Though multiple metrics have been proposed to evaluate the segmentation performance, there is no clear study on how or to what extent the segmentation errors will affect the diagnostic related features used in clinical practice. Therefore, we proposed a segmentation robustness plot (SRP) to build the link between segmentation errors and clinical acceptance, where relative area under the curve (R-AUC) was designed to help clinicians to identify the robust diagnostic related image features. In experiments, we first selected representative radiological series from time series (cardiac first-pass perfusion) and spatial series (T2 weighted images on brain tumors) of magnetic resonance images, respectively. Then, dice similarity coefficient (DSC) and Hausdorff distance (HD), as the widely used evaluation metrics, were used to systematically control the degree of the segmentation errors. Finally, the differences between diagnostic related image features extracted from the ground truth and the derived segmentation were analyzed, using the statistical method large sample size T-test to calculate the corresponding p values. The results are denoted in the SRP, where the x-axis indicates the segmentation performance using the aforementioned evaluation metric, and the y-axis shows the severity of the corresponding feature changes, which are expressed in either the p values for a single case or the proportion of patients without significant change. The experimental results in SRP show that when DSC is above 0.95 and HD is below 3 mm, the segmentation errors will not change the features significantly in most cases. However, when segmentation gets worse, additional metrics are required for further analysis. In this way, the proposed SRP indicates the impact of the segmentation errors on the severity of the corresponding feature changes. By using SRP, one could easily define the acceptable segmentation errors in a challenge. Additionally, the R-AUC calculated from SRP provides an objective reference to help the selection of reliable features in image analysis.

A CT-based nomogram for differentiating invasive fungal disease of the lung from bacterial pneumonia.

BACKGROUND: There is an annual increase in the incidence of invasive fungal disease (IFD) of the lung worldwide, but it is always a challenge for physicians to make an early diagnosis of IFD of the lung. Computed tomography (CT) may play a certain role in the diagnosis of IFD of the lung, however, there are no specific imaging signs for differentiating IFD of lung from bacterial pneumonia (BP). METHODS: A total of 214 patients with IFD of the lung or clinically confirmed BP were retrospectively enrolled from two institutions (171 patients from one institution in the training set and 43 patients from another institution in the test set). The features of thoracic CT images of the 214 patients were analyzed on the picture archiving and communication system by two radiologists, and these CT images were imported into RadCloud to perform radiomics analysis. A clinical model from radiologic analysis, a radiomics model from radiomics analysis and a combined model from integrating radiologic and radiomics analysis were constructed in the training set, and a nomogram based on the combined model was further developed. The area under the ROC curve (AUC) of the receiver operating characteristic (ROC) curve was calculated to assess the diagnostic performance of the three models. Decision curve analysis (DCA) was conducted to evaluate the clinical utility of the three models by estimating the net benefit at a range of threshold probabilities. RESULTS: The AUCs of the clinical model for differentiating IFD of lung from BP in the training set and test sets were 0.820 and 0.827. The AUCs of the radiomics model in the training set and test sets were 0.895 and 0.857. The AUCs of the combined model in the training set and test setswere 0.944 and 0.911. The combined model for differentiating IFD of lung from BP obtained the greatest net benefit among the three models by DCA. CONCLUSION: Our proposed nomogram, based on a combined model integrating radiologic and radiomics analysis, has a powerful predictive capability for differentiating IFD from BP. A good clinical outcome could be obtained using our nomogram.

Clinicopathological and prognostic analyses of 86 resected pulmonary lymphoepithelioma-like carcinomas.

BACKGROUND: Pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare subtype of primary lung cancer. The present study aims at investigating clinicopathological features and prognostic characteristics of the resected pulmonary LELC. METHODS: Patients with resected pulmonary LELC were identified in our hospital from December 2008 to December 2018. Data of these patients were retrospectively reviewed, clinicopathological features and prognostic characteristics were analyzed subsequently. RESULTS: In total, 86 patients were enrolled in the study, including 39 (45.3%) males and 47 (54.7%) females. Most of the serum tumor markers were normal. Immunohistochemical staining result showed frequent differentiation traits of epithelial tissue such. Positive PD-L1 (15 of 19, 78.9%) and PD-1 (13 of 17, 76.5%) were also common, but cancer-related genetic mutation was scarce (1 of 47, 2.1%). Survival analyses demonstrated that the N stage (p = .011) and extent of resection (p = .023) were identified as independent predictive factors for overall survival. CONCLUSIONS: Pulmonary LELC is a distinctive subtype of lung cancer with several exclusive traits, such as the trend to happen among nonsmoking young people, epithelial origin of tumor differentiation, frequent expression of the immune checkpoint, and scarce presence of driver mutation. In addition, pulmonary LELC was apt to get a favorable outcome, especially in cases diagnosed and treated in the early stage.

Biocompatible iron(II)-doped carbon dots as T1-weighted magnetic resonance contrast agents and fluorescence imaging probes.

The one-pot synthesis of iron-doped carbon quantum dots (Fe-CQDs) for use as both magnetic resonance (MR) and fluorescent (dual-mode) imaging nanoprobes is described. Comprehensive characterizations of the material confirmed the successful doping of the CQDs with Fe(II) ions. The imaging probe has a longitudinal relaxivity of 3.92 mM-1∙s-1 and a low r2/r1 ratio of 1.27, both of which are critical for T1-weighted contrast agents. The maximum emission of Fe-CQDs locates at 450 nm under 375 nm excitation, which also can be applied to fluorescence imaging. Biotoxicity assessment showed good biocompatibility of the Fe-CQDs. The in-vitro experiments with A549 cells indicated that the Fe-CQDs are viable candidates as dual-mode (MR/fluorescence) imaging nanoprobes. For in-vivo experiments, they exhibit high contrast efficiency, thereby improving the positive contrast in T1-weighted MR images. In-vivo time-dependent MRI of major organs showed that the Fe-CQDs undergo fast glomerular filtration and can evade immuno-absorption due to their ultra-small size and excellent biocompatibility. Graphical abstract Schematic presentation of the synthesis of Fe-CQDs and applications to magnetic resonance and fluorescent dual-mode imaging.

Pln24NT: a web resource for plant 24-nt siRNA producing loci.

ABSTRACT: In plants, 24 nucleotide small interfering RNAs (24-nt siRNAs) account for a large percentage of the total siRNA pool, and they play an important role in guiding plant-specific RNA-directed DNA methylation (RdDM), which transcriptionally silences transposon elements, transgenes, repetitive sequences and some endogenous genes. Several loci in plant genomes produce clusters of 24-nt RNAs, and these loci are receiving increasing attention from the research community. However, at present there is no bioinformatics resource dedicated to 24-nt siRNA loci and their derived 24-nt siRNAs. Thus, in this study, Pln24NT, a freely available web resource, was created to centralize 24-nt siRNA loci and 24-nt siRNA information, including fundamental locus information, expression profiles and annotation of transposon elements, from next-generation sequencing (NGS) data for 10 popular plant species. An intuitive web interface was also developed for convenient searching and browsing, and analytical tools were included to help users flexibly analyze their own siRNA NGS data. Pln24NT will help the plant research community to discover and characterize 24-nt siRNAs, and may prove useful for studying the roles of siRNA in RNA-directed DNA methylation in plants. AVAILABILITY AND IMPLEMENTATION: http://bioinformatics.caf.ac.cn/Pln24NT . CONTACT: suxh@caf.ac.cn. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

All-optical ultrafast polarization switching with nonlinear plasmonic metasurfaces.

Optical switching has important applications in optical information processing, optical computing, and optical communications. The long-term pursuit of optical switch is to achieve short switching time and large modulation depth. Among various mechanisms, all-optical switching based on Kerr effect represents a promising solution. However, it is usually difficult to compromise both switching time and modulation depth of a Kerr-type optical switch. To circumvent this constraint, symmetry selective polarization switching via second-harmonic generation (SHG) in nonlinear crystals has been attracting scientists' attention. Here, we demonstrate SHG-based all-optical ultrafast polarization switching by using geometric phase controlled nonlinear plasmonic metasurfaces. A switching time of hundreds of femtoseconds and a modulation depth of 97% were experimentally demonstrated. The function of dual-channel all-optical switching was also demonstrated on a metasurface, which consists of spatially variant meta-atoms. The nonlinear metasurface proposed here represents an important platform for developing all-optical ultrafast switches and would benefit the area of optical information processing.

Transcatheter arterial chemoembolisation combined with lenvatinib plus camrelizumab as conversion therapy for unresectable hepatocellular carcinoma: a single-arm, multicentre, prospective study.

Background: The synergistic effect of locoregional therapy in combination with systemic therapy as a conversion therapy for unresectable hepatocellular carcinoma (uHCC) is unclear. The purpose of this study was to evaluate the efficacy and safety of transcatheter arterial chemoembolisation (TACE) combined with lenvatinib and camrelizumab (TACE + LEN + CAM) as conversion therapy for uHCC. Methods: This single-arm, multicentre, prospective study was conducted at nine hospitals in China. Patients (aged 18-75 years) diagnosed with uHCC, an Eastern Cooperative Oncology Group performance score (ECOG-PS) of 0-1 and Child-Pugh class A received camrelizumab (200 mg, every 3 weeks) and lenvatinib (bodyweight ≥60 kg: 12 mg/day; <60 kg: 8 mg/day) after TACE treatment. Surgery was performed after tumour was assessed as meeting the criteria for resection. Patients who did not meet the criteria for surgery continued to receive triple therapy until disease progression or intolerable toxicity. Primary endpoints were objective response rate (ORR) according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST) and safety. Secondary endpoints included the surgical conversion rate, radical (R0) resection rate, and disease control rate (DCR). This study was registered with Chinese Clinical Trial Registry (ChiCTR2100050410). Findings: Between Oct 25, 2021, and July 20, 2022, 55 patients were enrolled. As of the data cutoff on June 1, 2023, the median follow-up was 13.3 months (IQR 10.6-15.9 months). The best tumour response to triple therapy was complete response (CR) in 9 (16.4%) patients, partial response (PR) in 33 (60.0%) patients, stable disease (SD) in 5 (9.1%) patients, or progressive disease (PD) in 7 (12.7%) patients. The ORR was 76.4% (42/55, 95% CI, 65.2-87.6%), and the DCR was 85.5% (47/55, 95% CI, 76.2-94.8%) per mRECIST. Twenty-four (43.6%) of the 55 patients suffered from grade 3-4 treatment-related adverse events (TRAEs). No grade 5 TRAEs occurred. A total of 30 (30/55, 54.5%) patients were converted to resectable HCC and 29 (29/55, 52.7%) patients underwent resection. The R0 resection rate was 96.6% (28/29). The major pathologic response (MPR) and pathologic complete response (pCR) rates in the surgery population were 65.5% (19/29) and 20.7% (6/29), respectively. Only one patient developed a Clavien-Dindo IIIa complication (abdominal infection). No Clavien-Dindo IIIb-V complications occurred. The median OS and median PFS were not reached. Interpretation: The triple therapy (TACE + LEN + CAM) is promising active for uHCC with a manageable safety. Moreover, triple therapy has good conversion efficiency and the surgery after conversion therapy is feasible and safe. To elucidate whether patients with uHCC accepting surgical treatment after the triple therapy can achieve better survival benefits than those who receive triple therapy only, well-designed randomised controlled trials are needed. Funding: This study was funded by the Natural Science Foundation of Fujian Province, China (2022J01691) and the Youth Foundation of Fujian Province Health Science and Technology Project, China (2022QNA035).

Comprehensive prognostic and immunological analysis of Ubiquitin Specific Peptidase 28 in pan-cancers and identification of its role in hepatocellular carcinoma cell lines.

BACKGROUND: Ubiquitin Specific Peptidase 28 (USP28), as a member of the DUBs family, has been reported to regulate the occurrence and development of some tumors, but its oncogenic role in tumor immunity is still unknown. METHODS: The comprehensive view of USP28 expression in tumor and normal samples was obtained from public databases, including The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Cancer Cell Line Encyclopedia (CCLE). We analyzed the genomic alterations of USP28 in various cancers using the cBioPortal dataset. Besides, gene set enrichment analysis was used to analyze the associated cancer hallmarks with USP28 expression, and TIMER2.0 was taken to investigate the immune cell infiltrations related to the USP28 level. RESULTS: USP28 is highly expressed in most tumors and has prognostic value across various cancer types. Moreover, a significant correlation exists between USP28 and immune regulators, clinical staging, checkpoint inhibitor response, MSI, TMB, CNV, MMR defects, and DNA methylation. Additionally, USP28 expression is strongly associated with the infiltration levels of neutrophils and NK cells in most tumor types. One of the most significant findings of our study was that USP28 could serve as a significant predictor of anti-CTLA4 therapy response in melanoma patients. Additionally, our molecular biology experiments validated that the knockdown of USP28 substantially reduced the proliferative and invasive abilities of the HCC cell lines. CONCLUSIONS: Our study suggests that USP28 could potentially serve as a biomarker for cancer immunologic infiltration and poor prognosis, with potential applications in developing novel cancer treatment strategies.

Comprehensively prognostic and immunological analysis of VRK Serine/Threonine Kinase 1 in pan-cancer and identification in hepatocellular carcinoma.

BACKGROUND: VRK1 is a member of the vaccinia-related kinase (VRK) family of serine/threonine protein kinases, which is related to the occurrence and development of malignant tumors. The expression pattern, predictive value, and biological function of VRK1 in various cancers remain largely elusive and warrant further investigation. METHODS: Public databases, such as TCGA, GTEx, and UCEC, were utilized to comprehensively analyze the expression of VRK1 across multiple cancer types. Prognostic significance was assessed through Univariate Cox regression and Kaplan-Meier analyses. Additionally, Spearman's correlation analysis was employed to explore the potential associations between VRK1 expression and various factors, including tumor microenvironment scores, immune cell infiltration, and immune-related genes. Moreover, to validate the findings, differential expression of VRK1 in HCC tissues and cell lines was further confirmed using qPCR, Western blot, and immunohistochemistry techniques. RESULTS: The upregulation of VRK1 was observed in most cancer types, and was associated with worse prognosis in ACC, KICH, KIRP, LGG, LIHC, LUAD, MESO, and PCPG. In various cancers, VRK1 expression exhibited positive correlations with immune infiltrating cells, immune checkpoint-related genes, TMB, and MSI. Furthermore, the promoter methylation status of VRK1 varied across different tumor types, and this variation was associated with patient prognosis in certain cancers. In our experimental analyses, we observed significantly elevated expression of VRK1 in both HCC tissues and HCC cells. Functionally, we found that the downregulation of VRK1 had a profound impact on HCC cells, leading to a significant decrease in their proliferation, migration, and invasion capabilities. CONCLUSION: The expression of VRK1 exerts a notable influence on the prognosis of several tumors and exhibits a strong correlation with tumor immune infiltration. Moreover, in the context of HCC, VRK1 may act as an oncogene, actively promoting tumor progression.

An implantable composite scaffold for amplified chemodynamic therapy and tissue regeneration.

Tissue regeneration and tumor cell killing after surgical resection are the two keys to achieving effective tumor therapy. In this study, an implantable system with combined functions of tumor therapy and tissue repair was constructed. Tannic acid (TA)/Fe3+ nanoparticles with Fenton catalytic activity were loaded with GSH inhibitor BSO drug (BTF), and acted as the therapeutic factor to realize amplified chemodynamic tumor treatment. Bioactive glass (BG) fibers loaded with vascular endothelial growth factor (VEGF) were used as the drug carrier matrix with tissue repair function (BGV). Then the BGV@BTF composite fibers were obtained by anchoring BTF nanoparticles on the surface of BGV fibers. Under tumorous acidic conditions, BTF nanoparticles can be released from the composite fibers, and taken up by tumor cells. Facilitated by BSO with the GSH suppression effect and TA with Fe3+ reducing properties, BTF nanoparticles can realize high oxidative stress in tumor cells and subsequent cell death. In addition, BG fibers and VEGF can both promote tissue regeneration and accelerate postoperative wound healing. The simultaneous suppression of tumor growth and promotion of tissue repair in this work is inspiring in the field of postoperative tumor treatment and recovery.

Scaffold-Free Tracheal Engineering via a Modular Strategy Based on Cartilage and Epithelium Sheets.

Tracheal defects lead to devastating problems, and practical clinical substitutes that have complex functional structures and can avoid adverse influences from exogenous bioscaffolds are lacking. Herein, a modular strategy for scaffold-free tracheal engineering is developed. A cartilage sheet (Cart-S) prepared by high-density culture is laminated and reshaped to construct a cartilage tube as the main load-bearing structure in which the chondrocytes exhibit a stable phenotype and secreted considerable cartilage-specific matrix, presenting a native-like grid arrangement. To further build a tracheal epithelial barrier, a temperature-sensitive technique is used to construct the monolayer epithelium sheet (Epi-S), in which the airway epithelial cells present integrated tight junctions, good transepithelial electrical resistance, and favorable ciliary differentiation capability. Epi-S can be integrally transferred to inner wall of cartilage tube, forming a scaffold-free complex tracheal substitute (SC-trachea). Interestingly, when Epi-S is attached to the cartilage surface, epithelium-specific gene expression is significantly enhanced. SC-trachea establishes abundant blood supply via heterotopic vascularization and then is pedicle transplanted for tracheal reconstruction, achieving 83.3% survival outcomes in rabbit models. Notably, the scaffold-free engineered trachea simultaneously satisfies sufficient mechanical properties and barrier function due to its matrix-rich cartilage structure and well-differentiated ciliated epithelium, demonstrating great clinical potential for long-segmental tracheal reconstruction.

Integration of CoAl-Layered Double Hydroxides on Commensal Bacteria to Enable Targeted Tumor Inhibition and Immunotherapy.

Combining targeted therapy and immunotherapy brings hope for a complete cancer cure. Due to their selective colonization and immune activation capacity, some bacteria have the potential to realize targeted immunotherapy. Herein, a biohybrid system was designed and synthesized by cladding NO3--intercalated cobalt aluminum layered double hydroxides (LDH) on anaerobic Propionibacterium acnes (PA) (PA@LDH). In this system, the covering of LDH reduces the pathogenicity of PA to normal tissues and alters its surface charge for prolonged in vivo circulation. Once the tumor site is reached, the acid-responsive degradation of LDH enables PA exposure. PA can colonize and convert nitrate ions to nitric oxide (NO) through denitrification. Then, NO reacts with intracellular O2·- to produce toxic reactive nitrogen species ONOO- and induce tumor cell apoptosis. In addition, cobalt ions released from LDH can inhibit the activity of superoxide dismutase (SOD), thus increasing the level of O2·- and further enhancing the antitumor effect. Moreover, PA exposure activates M2-to-M1 macrophage polarization and a range of immune responses, thereby achieving a sustained antitumor activity. In vitro and in vivo results reveal that the biohybrid system eliminates solid tumors and inhibits tumor metastasis effectively. Overall, the biohybrid strategy provides a new avenue for realizing simultaneous immunotherapy and targeted therapy.

A bioengineered trachea-like structure improves survival in a rabbit tracheal defect model.

A practical strategy for engineering a trachea-like structure that could be used to repair or replace a damaged or injured trachea is an unmet need. Here, we fabricated bioengineered cartilage (BC) rings from three-dimensionally printed fibers of poly(ɛ-caprolactone) (PCL) and rabbit chondrocytes. The extracellular matrix (ECM) secreted by the chondrocytes combined with the PCL fibers formed a "concrete-rebar structure," with ECM deposited along the PCL fibers, forming a grid similar to that of native cartilage. PCL fiber-hydrogel rings were then fabricated and alternately stacked with BC rings on silicone tubes. This trachea-like structure underwent vascularization after heterotopic transplantation into rabbits for 4 weeks. The vascularized bioengineered trachea-like structure was then orthotopically transplanted by end-to-end anastomosis to native rabbit trachea after a segment of trachea had been resected. The bioengineered trachea-like structure displayed mechanical properties similar to native rabbit trachea and transmural angiogenesis between the rings. The 8-week survival rate in transplanted rabbits was 83.3%, and the respiratory rate of these animals was similar to preoperative levels. This bioengineered trachea-like structure may have potential for treating tracheal stenosis and other tracheal injuries.

Significant Enhancement of Circular Polarization in Light Emission through Controlling Helical Pitches of Semiconductor Nanohelices.

Circularly polarized light emission (CPLE) can be potentially applied to three-dimensional displays, information storage, and biometry. However, these applications are practically limited by a low purity of circular polarization, i.e., the small optical dissymmetry factor gCPLE. Herein, glancing angle deposition (GLAD) is performed to produce inorganic nanohelices (NHs) to generate CPLE with large gCPLE values. CdSe NHs emit red CPLE with gCPLE = 0.15 at a helical pitch (P) ≈ 570 nm, having a 40-fold amplification of gCPLE compared to that at P ≈ 160 nm. Ceria NHs emit ultraviolet-blue CPLE with gCPLE ≈ 0.06 at P ≈ 830 nm, with a 103-fold amplification compared to that at P ≈ 110 nm. Both the photoluminescence and scattering among the close-packed NHs complicatedly account for the large gCPLE values, as revealed by the numerical simulations. The GLAD-based NH-fabrication platform is devised to generate CPLE with engineerable color and large gCPLE = 10-2-10-1, shedding light on the commercialization of CPLE devices.

Extracellular Vesicles in Tissue Engineering: Biology and Engineered Strategy.

Extracellular vesicles (EVs), acting as an important ingredient of intercellular communication through paracrine actions, have gained tremendous attention in the field of tissue engineering (TE). Moreover, these nanosized extracellular particles (30-140 nm) can be incorporated into biomaterials according to different principles to facilitate signal delivery in various regenerative processes directly or indirectly. Bioactive biomaterials as the carrier will extend the retention time and realize the controlled release of EVs, which further enhance their therapeutic efficiency in tissue regeneration. Herein, the basic biological characteristics of EVs are first introduced, and then their outstanding performance in exerting direct impacts on target cells in tissue regeneration as well as indirect effects on promoting angiogenesis and regulating the immune environment, due to specific functional components of EVs (nucleic acid, protein, lipid, etc.), is emphasized. Furthermore, different design ideas for suitable EV-loaded biomaterials are also demonstrated. In the end, this review also highlights the engineered strategies, which aim at solving the problems related to natural EVs such as highly heterogeneous functions, inadequate tissue targeting capabilities, insufficient yield and scalability, etc., thus promoting the therapeutic pertinence and clinical potential of EV-based approaches in TE.