Hypoxia Reversion by Low-Immunogenic Ultra-Acid-Sensitive Comicelles of Protein-Polymer Conjugates Sensitizes Tumors to Photodynamic Therapy.

Hypoxia is characteristic of the tumor microenvironment, which is correlated with resistance to photodynamic therapy (PDT), radiotherapy, chemotherapy, and immunotherapy. Catalase is potentially useful to catalyze the conversion of endogenous H2O2 to O2 for hypoxia reversion. However, the efficient delivery of catalase into the hypoxia regions of tumors is a huge challenge. Here, we report the self-assembly of ultra-acid-sensitive polymer conjugates of catalase and albumin into nanomicelles that are responsive to the acidic tumor microenvironment. The immunogenicity of catalase is mitigated by the presence of albumin, which reduces the cross-linking of catalase with B cell receptors, resulting in improved pharmacokinetics. The ultra acid sensitivity of the nanomicelles makes it possible to efficiently escape the lysosomal degradation after endocytosis and permeate into the interior of tumors to reverse hypoxia in vitro and in vivo. In mice bearing triple-negative breast cancer, the nanomicelles loaded with a photosensitizer effectively accumulate and penetrate into the whole tumors to generate a sufficient amount of O2 to reverse hypoxia, leading to enhanced efficacy of PDT without detectable side effects. These findings provide a general strategy of self-assembly to design low-immunogenic ultra-acid-sensitive comicelles of protein-polymer conjugates to reverse tumor hypoxia, which sensitizes tumors to PDT.

Progress and challenges of in vivo flow cytometry and its applications in circulating cells of eyes.

Circulating inflammatory cells in eyes have emerged as early indicators of numerous major diseases, yet the monitoring of these cells remains an underdeveloped field. In vivo flow cytometry (IVFC), a noninvasive technique, offers the promise of real-time, dynamic quantification of circulating cells. However, IVFC has not seen extensive applications in the detection of circulating cells in eyes, possibly due to the eye's unique physiological structure and fundus imaging limitations. This study reviews the current research progress in retinal flow cytometry and other fundus examination techniques, such as adaptive optics, ultra-widefield retinal imaging, multispectral imaging, and optical coherence tomography, to propose novel ideas for circulating cell monitoring.

A causality-inspired generalized model for automated pancreatic cancer diagnosis.

Pancreatic cancer (PC) is a severely malignant cancer variant with high mortality. Since PC has no obvious symptoms, most PC patients are belatedly diagnosed at advanced disease stages. Recently, artificial intelligence (AI) approaches have demonstrated promising prospects for early diagnosis of pancreatic cancer. However, certain non-causal factors (such as intensity and texture appearance variations, also called confounders) tend to induce spurious correlation with PC diagnosis. This undermines the generalization performance and the clinical applicability of the AI-based PC diagnosis approaches. Therefore, we propose a causal intervention based automated method for pancreatic cancer diagnosis with contrast-enhanced computerized tomography (CT) images, where a confounding effects reduction scheme is developed for alleviating spurious correlations to achieve unbiased learning, thereby improving the generalization performance. Specifically, a continuous image generation strategy was developed to simulate wide variations of intensity differences caused by imaging heterogeneities, where Monte Carlo sampling is added to further enhance the continuity of simulated images. Then, to enhance the pancreatic texture variability, a texture diversification method was introduced in conjunction with gradient-based data augmentation. Finally, a causal intervention strategy was proposed to alleviate the adverse confounding effects by decoupling the causal and non-causal factors and combining them randomly. Extensive experiments showed remarkable diagnosis performance on a cross-validation dataset. Also, promising generalization performance with an average accuracy of 0.87 was attained on three independent test sets of a total of 782 subjects. Therefore, the proposed method shows high clinical feasibility and applicability for pancreatic cancer diagnosis.

A 3D nanoscale optical disk memory with petabit capacity.

High-capacity storage technologies are needed to meet our ever-growing data demands1,2. However, data centres based on major storage technologies such as semiconductor flash devices and hard disk drives have high energy burdens, high operation costs and short lifespans2,3. Optical data storage (ODS) presents a promising solution for cost-effective long-term archival data storage. Nonetheless, ODS has been limited by its low capacity and the challenge of increasing its areal density4,5. Here, to address these issues, we increase the capacity of ODS to the petabit level by extending the planar recording architecture to three dimensions with hundreds of layers, meanwhile breaking the optical diffraction limit barrier of the recorded spots. We develop an optical recording medium based on a photoresist film doped with aggregation-induced emission dye, which can be optically stimulated by femtosecond laser beams. This film is highly transparent and uniform, and the aggregation-induced emission phenomenon provides the storage mechanism. It can also be inhibited by another deactivating beam, resulting in a recording spot with a super-resolution scale. This technology makes it possible to achieve exabit-level storage by stacking nanoscale disks into arrays, which is essential in big data centres with limited space.

In vivo photoacoustic flow cytometry-based study of the effect of melanin content on melanoma metastasis.

A major cause of death in cancer patients is distant metastasis of tumors, in which circulating tumor cells (CTCs) are an important marker. Photoacoustic flow cytometry (PAFC) can monitor CTCs in real time, non-invasively, and label-free; we built a PAFC system and validated the feasibility of PAFC for monitoring CTCs using in vivo animal experiments. By cultivating heavily-pigmented and moderately-pigmented melanoma cells, more CTCs were detected in mice inoculated with moderately-pigmented tumor cells, resulting in more distant metastases and poorer survival status. Tumor cells with lower melanin content may produce more CTCs, increasing the risk of metastasis. CTC melanin content may be down-regulated during the metastatic which may be a potential indicator for assessing the risk of melanoma metastasis. In conclusion, PAFC can be used to assess the risk of melanoma metastasis by dynamically monitoring the number of CTCs and the CTC melanin content in future clinical diagnoses.

Radiofrequency ablation induces tumor cell dissemination in a mouse model of hepatocellular carcinoma.

BACKGROUND: We tested the hypothesis that radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) promotes tumor cell release and explored a method for reducing these effects. METHODS: A green fluorescent protein-transfected orthotopic HCC model was established in 99 nude mice. In vivo flow cytometry was used to monitor circulating tumor cell (CTC) dynamics. Pulmonary fluorescence imaging and pathology were performed to investigate lung metastases. First, the kinetics of CTCs during the periablation period and the survival rate of CTCs released during RFA were investigated. Next, mice were allocated to controls, sham ablation, or RFA with/without hepatic vessel blocking (ligation of the portal triads) for evaluating the postablation CTC level, lung metastases, and survival over time. Moreover, the kinetics of CTCs, lung metastases, and mice survival were evaluated for RFA with/without ethanol injection. Pathological changes in tumors and surrounding parenchyma after ethanol injection were noted. Statistical analysis included t-test, ANOVA, and Kaplan-Meier survival curves. RESULTS: CTC counts were 12.3-fold increased during RFA, and 73.7% of RFA-induced CTCs were viable. Pre-RFA hepatic vessel blocking prevented the increase of peripheral CTCs, reduced the number of lung metastases, and prolonged survival (all p ≤ 0.05). Similarly, pre-RFA ethanol injection remarkably decreased CTC release during RFA and further decreased lung metastases with extended survival (all p ≤ 0.05). Histopathology revealed thrombus formation in blood vessels after ethanol injection, which may clog tumor cell dissemination during RFA. CONCLUSION: RFA induces viable tumor cell dissemination, and pre-RFA ethanol injection may provide a prophylactic strategy to reduce this underestimated effect. RELEVANCE STATEMENT: RFA for HCC promotes viable tumor cell release during ablation, while ethanol injection can prevent RFA induced tumor cell release. KEY POINTS: • RFA induced the release of viable tumor cells during the ablation procedure in an animal model. • Hepatic vessel blocking can suppress tumor cells dissemination during RFA. • Ethanol injection can prevent RFA-induced tumor cell release, presumably because of the formation of thrombosis.

Measurement of red blood cell deformability during morphological changes using rotating-glass-plate-based scanning optical tweezers.

It is important to measure the deformability of red blood cells (RBCs) before transfusion, which is a key factor in the gas transport ability of RBCs and changes during storage of RBCs in vitro. Moreover, the morphology of RBCs also changes during storage. It is proposed that the change in morphology is related to the change in deformability. However, the efficiency of typical methods that use particles as handles is low, especially in the deformability measurement of echinocyte and spherocytes. Therefore, the deformability of RBCs with different morphologies is hard to be measured and compared in the same experiment. In this study, we developed a cost-effective and efficient rotating-glass-plate-based scanning optical tweezers device for the measurement of deformability of RBCs. The performance of this device was evaluated, and the deformability of three types of RBCs was measured using this device. Our results clearly show that the change of erythrocyte morphology from discocyte to echinocyte and spherocyte during storage in vitro is accompanied by a decrease in deformability.

Spatiotemporally-Programmed Dual-Acid-Sensitive Nanoworms of Albumin-Poly(tertiary amine)-Doxorubicin Conjugates for Enhanced Cancer Chemotherapy.

Nanomedicines are potentially useful for targeted cancer chemotherapy; however, it is difficult to design nanomedicines with controllable structures and functions to overcome a series of biological and pathological barriers to efficiently kill cancer cells in vivo. Here, this work reports in situ growth of dual-acid-sensitive poly(tertiary amine)-doxorubicin conjugates from albumin to form dual-acid-sensitive albumin-poly(tertiary amine)-doxorubicin conjugates that self-assemble into nanospheres and nanoworms in a controlled manner. Both nanospheres and nanoworms rapidly dissociate into positively-charged unimers at pH < 6.9 and quickly releases the conjugated drug of doxorubicin at pH < 5.6, leading to enhanced penetration in tumor cell spheroids as well as improved uptake and cytotoxicity to tumor cells at pH < 6.9. Notably, nanoworms are less taken up by endothelial cells than nanospheres and doxorubicin, leading to improved pharmacokinetics. In a mouse model of triple negative breast cancer, nanoworms accumulate and penetrate into tumors more efficiently than nanospheres and doxorubicin, leading to enhanced tumor accumulation and penetration. As a result, nanoworms outperform nanospheres and doxorubicin in suppressing tumor growth and elongating the animal survival time, without observed side effects. These findings demonstrate that intelligent nanoworms with spatiotemporally programmed dual-acid-sensitive properties are promising as next-generation nanomedicines for targeted cancer chemotherapy.

Biocompatible polymer optical fiber with a strongly scattering spherical end for interstitial photodynamic therapy.

Interstitial photodynamic therapy (I-PDT), which utilizes optical fibers to deliver light for photosensitizer excitation and the elimination of penetration depth limitation, is a promising modality in the treatment of deeply seated tumors or thick tumors. Currently, the excitation domain of the optical fiber is extremely limited, restricting PDT performance. Here, we designed and fabricated a biocompatible polymer optical fiber (POF) with a strongly scattering spherical end (SSSE) for I-PDT applications, achieving an increased excitation domain and consequently excellent in vitro and in vivo therapeutical outcomes. The POF, which was drawn using a simple thermal drawing method, was made of polylactic acid, ensuring its superior biocompatibility. The excitation domains of POFs with different ends, including flat, spherical, conical, and strongly scattering spherical ends, were analyzed and compared. The SSSE was achieved by introducing nanopores into a spherical end, and was further optimized to achieve a large excitation domain with an even intensity distribution. The optimized POF enabled outstanding therapeutic performance of I-PDT in in vitro cancer cell ablation and in vivo anticancer therapy. All of its notable optical features, including low transmission/bending loss, superior biocompatibility, and a large excitation domain with an even intensity distribution, endow the POF with great potential for clinical I-PDT applications.

Site-selective superassembly of biomimetic nanorobots enabling deep penetration into tumor with stiff stroma.

Chemotherapy remains as the first-choice treatment option for triple-negative breast cancer (TNBC). However, the limited tumor penetration and low cellular internalization efficiency of current nanocarrier-based systems impede the access of anticancer drugs to TNBC with dense stroma and thereby greatly restricts clinical therapeutic efficacy, especially for TNBC bone metastasis. In this work, biomimetic head/hollow tail nanorobots were designed through a site-selective superassembly strategy. We show that nanorobots enable efficient remodeling of the dense tumor stromal microenvironments (TSM) for deep tumor penetration. Furthermore, the self-movement ability and spiky head markedly promote interfacial cellular uptake efficacy, transvascular extravasation, and intratumoral penetration. These nanorobots, which integrate deep tumor penetration, active cellular internalization, near-infrared (NIR) light-responsive release, and photothermal therapy capacities into a single nanodevice efficiently suppress tumor growth in a bone metastasis female mouse model of TNBC and also demonstrate potent antitumor efficacy in three different subcutaneous tumor models.

Performance of indocyanine green in sentinel lymph node mapping and lymph node metastasis in penile cancer: systematic review, meta-analysis, and single-center experience.

PURPOSE: The aim of this study was to investigate the overall sensitivity and specificity of indocyanine green (ICG)-near-infrared (NIR) fluorescence imaging in the detection of sentinel lymph node metastasis (SLNM) in penile cancer. METHODS: We searched PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases to identify manuscripts where ICG was intravenously administered prior to or during penile cancer surgery, with no restriction on language or publication status. The results extracted are presented as forest plots. RESULTS: Seven studies were included in the analysis. The median sensitivity and specificity of ICG-NIR imaging for SLNM detection were 100 and 4%, respectively; the pooled sensitivity was 100.0% (95% confidence interval [CI] 97.0-100.0) and specificity was 2.0% (95% CI 1.0-3.0). There was no significant difference in the diagnostic results between different injection sites and doses in each experimental group. CONCLUSION: To our knowledge, this meta-analysis is the first to summarize the diagnostic performance of ICG-NIR imaging for SLNM detection in penile cancer. ICG is sensitive in the imaging of SLN tissue, which can consequently improve the accuracy of lymph node detection. However, the specificity is very low.

Deep-learning visualization enhancement method for optical coherence tomography angiography in dermatology.

Optical coherence tomography angiography (OCTA) in dermatology usually suffers from low image quality due to the highly scattering property of the skin, the complexity of cutaneous vasculature, and limited acquisition time. Deep-learning methods have achieved great success in many applications. However, the deep learning approach to improve dermatological OCTA images has not been investigated due to the requirement of high-performance OCTA systems and difficulty of obtaining high-quality images as ground truth. This study aims to generate proper datasets and develop a robust deep learning method to enhance the skin OCTA images. A swept-source skin OCTA system was employed to create low-quality and high-quality OCTA images with different scanning protocols. We propose a model named vascular visualization enhancement generative adversarial network and adopt an optimized data augmentation strategy and perceptual content loss function to achieve better image enhancement effect with small amount of training data. We demonstrate the superiority of the proposed method in skin OCTA image enhancement by quantitative and qualitative comparisons.

In vivo flow cytometry reveals an anti-metastatic effect of Rujifang in triple-negative breast cancer.

Breast cancer is the most common cancer, and triple-negative breast cancer (TNBC) has the highest metastasis and mortality rate among all breast cancer subtypes. Rujifang is a traditional Chinese medicine formula with many years of clinical application in breast cancer treatment. Here, we aim to investigate the effects of Rujifang on circulating tumor cell (CTC) dynamics and the tumor microenvironment in a ZsGreen/luciferase double-labeled TNBC orthotopic model. We report that the number of CTCs monitored by in vivo flow cytometry (IVFC) strongly correlates with disease progression. Rujifang treatment decreased the number of CTCs and suppressed the distant metastasis of TNBC. Moreover, immunofluorescence analysis revealed that Rujifang treatment could affect the tumor microenvironment by downregulating Kindlin-1, which has been reported to promote metastasis of TNBC. Our study provides evidence of the anti-metastatic effect of Rujifang against TNBC in an animal model using fluorescent cell lines. The results suggest the potential therapeutic value of Rujifang as an anti-metastatic drug, however, further clinical trials are needed to validate these findings in humans.

Advanced flow cytometry for biomedical applications.

Flow cytometry (FC) is a versatile tool with excellent capabilities to detect and measure multiple characteristics of a population of cells or particles. Notable advancements in in vivo photoacoustic FC, coherent Raman FC, microfluidic FC, and so on, have been achieved in the last two decades, which endows FC with new functions and expands its applications in basic research and clinical practice. Advanced FC broadens the tools available to researchers to conduct research involving cancer detection, microbiology (COVID-19, HIV, bacteria, etc.), and nucleic acid analysis. This review presents an overall picture of advanced flow cytometers and provides not only a clear understanding of their mechanisms but also new insights into their practical applications. We identify the latest trends in this area and aim to raise awareness of advanced techniques of FC. We hope this review expands the applications of FC and accelerates its clinical translation.

CD83+ B cells alleviate uveitis through inhibiting DCs by sCD83.

Soluble CD83 (sCD83) exerts immunosuppressive functions in many autoimmune diseases, including experimental autoimmune uveitis (EAU), but the cells and mechanisms involved are unclear. This study showed that CD83+ B cells were the main sources of sCD83. They alleviated the symptoms of EAU and decreased the percentage of T cells and DCs in the eyes and lymph nodes. These CD83+ B cells decreased IL-1ß, IL-18 and IFN-γ secretion by DCs through sCD83. sCD83 interacted with GTPase Ras-related protein (Rab1a) in DCs to promote Rab1a accumulation in autolysosomes and inhibit mTORC1 phosphorylation and NLRP3 expression. Hence, CD83+ B cells play a regulatory role in EAU by secreting sCD83. The lack of regulation of CD83+ B cells might be an important factor leading to hyperimmune activation in patients with autoimmune uveitis. CD83+ B cells suppress activated DCs in uveitis, indicating the potential therapeutic role of CD83+ B cells in uveitis.

In vivo corneal elastography: A topical review of challenges and opportunities.

Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.

Regulation of ERα-dependent breast cancer metastasis by a miR-29a signaling.

Malignant breast cancer (BC) remains incurable mainly due to the cancer cell metastasis, which is mostly related to the status of Estrogen receptor alpha (ERα). However, our understanding of the mechanisms through which ERα regulates cancer cell metastasis remains limited. Here we identified a miR-29a-PTEN-AKT axis as a downstream signaling pathway of ERα governing breast cancer progression and metastasis. Two estrogen response element (ERE) half sites were identified in the promoter and enhancer regions of miR-29a, which mediated transcriptional regulation of miR-29a by ERα. Low level of miR-29a showed association with reduced metastasis and better survival in ERα+ luminal subtype of BC. In contrast, high level of miR-29a was detected in ERα- triple negative breast cancer (TNBC) in association with distant metastasis and poor survival. miR-29a overexpression in BC tumors increased the number of circulating tumor cells and promoted lung metastasis in mice. Targeted knockdown of miR-29a in TNBC cells in vitro or administration of a nanotechnology-based anti-miR-29a delivery in TNBC tumor-bearing mice in vivo suppressed cellular invasion, EMT and lung metastasis. PTEN was identified as a direct target of miR-29a, inducing EMT and metastasis via AKT signaling. A small molecular inhibitor of AKT attenuated miR-29a-induced EMT. These findings demonstrate a novel mechanism responsible for ERα-regulated breast cancer metastasis, and reveal the combination of ERα status and miR-29a levels as a new risk indicator in BC.

Superior biocompatible carbon dots for dynamic fluorescence imaging of nucleoli in living cells.

The nucleolus is a newly developed and promising target for cancer diagnosis and therapy, and its imaging is extremely significant for fundamental research and clinical applications. The unique feature, i.e., high resolution at the subcellular level, makes the fluorescence imaging method a powerful tool for nucleolus imaging. However, the fluorescence imaging of nucleoli in living cells is restricted by the limited availability of fluorescent agents with specific nucleolus-targeting capability and superior biocompatibility. Here, promising carbon dots (CDs) with intrinsic nucleolus-targeting capability were synthesized, characterized and employed for dynamic fluorescence imaging of nucleoli in living cells. The CDs exhibit a high fluorescence quantum yield of 0.2, excellent specificity and photostability, and superior biocompatibility, which were systematically demonstrated at the gene, cellular and animal levels and confirmed by their biological effects on embryonic development. All these features enabled CDs to light up the nucleoli for a long time with a high signal-to-noise ratio in living cells and monitor the nucleolar dynamics of malignant cells in camptothecin (CPT) based chemotherapy. Their excellent optical and biological features as well as general nucleolus-targeting capability endow CDs with great potential for future translational research.

Epidural Pulsation Accelerates the Drainage of Brain Interstitial Fluid.

Unhindered transportation of substances in the brain extracellular space (ECS) is essential for maintaining brain function. Regulation of transportation is a novel strategy for treating ECS blockage-related brain diseases, but few techniques have been developed to date. In this study, we established a novel approach for accelerating the drainage of brain interstitial fluid (ISF) in the ECS using minimally invasive surgery, in which a branch of the external carotid artery is separated and implanted epidurally (i.e., epidural arterial implantation [EAI]) to promote a pulsation effect on cerebrospinal fluid (CSF) in the frontoparietal region. Tracer-based magnetic resonance imaging was used to evaluate the changes in ISF drainage in rats 7 and 15 days post-EAI. The drainage of the traced ISF from the caudate nucleus to ipsilateral cortex was significantly accelerated by EAI. Significant increases in the volume fraction of the ECS and molecular diffusion rate were demonstrated using the DECS-mapping technique, which may account for the mechanisms underlying the changes in brain ISF. This study provides a novel perspective for encephalopathy treatment via the brain ECS.

Generalized pancreatic cancer diagnosis via multiple instance learning and anatomically-guided shape normalization.

Pancreatic cancer is a highly malignant cancer type with a high mortality rate. As no obvious symptoms are associated with this cancer type, most of the diagnoses are made when the patients are already in a late stage. In this work, we propose an automated method for effective early diagnosis of pancreatic cancer based on multiple instance learning with contrast-enhanced CT images. In this method, diagnosis stability and generalizability were improved through shape normalization based on anatomical structures as well as instance-level contrastive learning. Specifically, anatomically-guided shape normalization were developed to reconstruct the pancreatic regions of interest by spatial transformations, account for larger tumor parts in these regions, and hence enhance the extraction of pancreatic features. Moreover, instance-level contrastive learning was employed to aggregate different types of tumor features within the multiple instance learning framework. This learning approach can maintain the tumor feature integrity and enhance the diagnosis stability. Finally, a balance-adjustment strategy was designed to alleviate the class imbalance problem caused by the scarcity of tumor samples. Extensive experimental results demonstrated remarkable performance of our method when conducted cross-validation on an in-house dataset with 310 patients and independent test on two unseen datasets (a private test set with 316 and a publicly-available test set with 281). The proposed strategies also led to significant improvements in generalizability. Besides, the clinical significance of the proposed method was further verified through two independent test results in which tumors smaller than 2 cm in diameter were identified at accuracies of 80.9% and 90.1%, respectively. Overall, our method provides a potentially successful tool for early diagnosis of pancreatic cancer. Our source codes will be released at https://github.com/SJTUBME-QianLab/MIL_PAdiagnosis.