Risk Factors, Patterns, and Outcomes of Late Recurrence After Liver Resection for Hepatocellular Carcinoma: A Multicenter Study From China

Importance

Late recurrence (more than 2 years) after liver resection for hepatocellular carcinoma (HCC) is generally considered as a multicentric tumor or a de novo cancer.

Objective

To investigate the risk factors, patterns, and outcomes of late recurrence after curative liver resection for HCC.

Design, Setting, and Participants

This study was a multicenter retrospective analysis of patients who underwent curative liver resection for HCC at 6 hospitals in China from January 2001 to December 2015. Among 734 patients who were alive and free of recurrence at 2 years after resection, 303 patients developed late recurrence. Data were analyzed from June 2017 to February 2018.

Interventions

Liver resection for HCC.

Main Outcomes and Measures

Risk factors of late recurrence as well as patterns, treatments, and long-term outcomes of patients with late recurrence. Univariate and multivariate Cox regression analyses were performed to identify independent risk factors of late recurrence.

Results

Of the included 734 patients, 652 (88.8%) were male, and the mean (SD) age was 51.0 (10.3) years. At a median (interquartile range) follow-up of 78.0 (52.8-112.5) months, 303 patients (41.3%) developed late recurrence. Multivariate analysis revealed that male sex, cirrhosis, multiple tumors, satellite nodules, tumor size greater than 5 cm, and macroscopic and microscopic vascular invasion were independent risk factors of late recurrence. Of the 303 patients with late recurrence, 273 (90.1%) had only intrahepatic recurrence, 30 (9.9%) had both intrahepatic and extrahepatic recurrence, and none had only extrahepatic recurrence. Potentially curative treatments were given to 165 of 303 patients (54.5%) with late recurrence, which included reresection, transplant, and local ablation. Multivariate Cox regression analysis showed that regular surveillance for postoperative recurrence (hazard ratio [HR], 0.470; 95% CI, 0.310-0.713; P = .001), cirrhosis (HR, 1.381; 95% CI, 1.049-1.854; P = .02), portal hypertension (HR, 2.424; 95% CI, 1.644-3.574; P < .001), Child-Pugh grade of B or C (HR, 1.376; 95% CI, 1.153-1.674; P < .001), Barcelona Clinic Liver Cancer stage B (HR, 1.304; 95% CI, 1.007-1.708; P = .04) and stage C (HR, 2.037; 95% CI, 1.583-2.842; P < .001), and potentially curative treatment (HR, 0.443; 95% CI, 0.297-0.661; P < .001) were independent predictors of overall survival for patients with late recurrence.

Conclusions and Relevance

Late recurrence after HCC resection was associated with sex, cirrhosis, and several aggressive tumor characteristics of the initial HCC. The patterns of late recurrence suggested surveillance for recurrence after 2 years of surgery should be targeted to the liver. Postoperative surveillance improved the chance of potentially curative treatments, with improved survival outcomes in patients with late recurrence.

Chlorin e6 Conjugated Poly(dopamine) Nanospheres as PDT/PTT Dual-Modal Therapeutic Agents for Enhanced Cancer Therapy

Photodynamic therapy (PDT), using a combination of chemical photosensitizers (PS) and light, has been successfully applied as a noninvasive therapeutic procedure to treat tumors by inducing apoptosis or necrosis of cancer cells. However, most current clinically used PS have suffered from the instability in physiological conditions which lead to low photodynamic therapy efficacy. Herein, a highly biocompatible poly(dopamine) (PDA) nanoparticle conjugated with Chlorin e6 (referenced as the PDA-Ce6 nanosphere) was designed as a nanotherapeutic agent to achieve simultaneous photodynamic/photothermal therapy (PDT/PTT). Compared to the free Ce6, the PDA-Ce6 nanosphere exhibited significantly higher PDT efficacy against tumor cells, because of the enhanced cellular uptake and subsequently greater reactive oxygen species (ROS) production upon laser irradiation at 670 nm. Meanwhile, the PDA-Ce6 nanosphere could be also used as a photoabsorbing agent for PTT, because of the excellent photothermal conversion ability of PDA nanoparticle under laser irradiation at 808 nm. Moreover, our prepared nanosphere had extremely low dark toxicity, while excellent phototoxicity under the combination laser irradiation of 670 and 808 nm, both in vitro and in vivo, compared to any single laser irradiation alone. Therefore, our prepared PDA-Ce6 nanosphere could be applied as a very promising dual-modal phototherapeutic agent for enhanced cancer therapy in future clinical applications.

Liposome-Mediated In Situ Formation of Type-I Heterojunction for Amplified Photoelectrochemical Immunoassay

Exploiting innovative sensing mechanisms and their rational implementation for selective and sensitive detection has recently become one of the mainstream research directions of photoelectrochemical (PEC) bioanalysis. In contrast to existing conventional strategies, this study presents a new liposome-mediated method via in situ combining ZnInS nanosheets (ZIS NSs) with SnS₂ to form a ZIS NSs/SnS₂ type-I heterojunction on fluorine-doped tin oxide (FTO) electrodes for highly sensitive PEC immunoassays. Specifically, alkaline phosphatase (ALP)-encapsulated liposomes were confined within 96-well plates by sandwich immunorecognition and subsequently subjected to lysis treatment. Enzymatically produced H₂S by the released ALP was then directed to react with Sn(IV) to engender the ZIS NSs/SnS₂ type-I heterojunction on the FTO/ZIS NSs-Sn(IV) electrode, resulting in a change in the photogenerated electron-hole transfer path of the photoelectrode and reduction in current signaling. Exemplified by heart-type fatty acid binding protein (h-FABP) as a target, the constructed PEC sensor showed good stability and selectivity in a biosensing system. Under optimal conditions, the as-prepared sensing platform displayed high sensitivity for h-FABP with a dynamic linear response range of 0.1-1000 pg/mL and a lower detection limit of 55 fg/mL. This research presents the liposome-mediated PEC immunoassay based on in situ type-I heterojunction establishment, providing a new protocol for analyzing various targets of interest.

Exploiting Photoelectric Activities and Piezoelectric Properties of NaNbO3 Semiconductors for Point-of-Care Immunoassay

Point-of-care testing (POCT) technology has made major breakthroughs in community medicine and physician office situations, in tandem with the more ubiquitous and intensive usage of highly integrated quick detection equipment for illness diagnosis, personal care, and mobile healthcare. Although the photoelectrochemical (PEC)-based POCT platform offers the benefits of cheap cost and good user engagement, its commercialization is still limited by the photodetection components' downsizing and mobility, among other factors. In this work, a novel highly integrated PEC biosensor aided by piezophototronics to enhance the efficiency of PEC testing was reported for flexible detection of cancer-associated antigens in biological fluids (prostate-specific antigen, PSA, used as an example). Multiple signal enhancement strategies, including a magnetic bead-linked enzyme-linked immune system catalyzing the production of ascorbic acid from the substrate and a piezoelectric-assisted enhancement strategy, were used for sensitive detection of the analyte to be tested in human body fluids. Unlike the electron transfer mechanism in heterojunctions, piezoelectric semiconductors promote the transfer of electrons and holes by generating piezoelectric potentials in the ultrasonic field, thus contributing to the performance of the PEC testbed. Under optimized conditions, the test platform achieves good correspondence for PSA at 0.02-40 ng mL^-1. Impressively, the test devices are comparable to or even superior to gold standard ELISA kits in terms of cost approval and batch testing. This research demonstrates the potential of piezoelectric semiconductors for POC applications in revolutionary PECs and offers innovative thoughts for the development of new PEC bioanalytical components.

Lipid-AuNPs@PDA nanohybrid for MRI/CT imaging and photothermal therapy of hepatocellular carcinoma

Multifunctional theranostic nanoparticles represent an emerging agent with the potential to offer extremely sensitive diagnosis and targeted cancer therapy. Herein, we report the synthesis and characterization of a multifunctional theranostic agent (referred to as LA-LAPNHs) for targeted magnetic resonance imaging/computed X-ray tomography (MRI/CT) dual-mode imaging and photothermal therapy of hepatocellular carcinoma. The LA-LAPNHs were characterized as having a core-shell structure with the gold nanoparticles (AuNPs)@polydopamine (PDA) as the inner core, the indocyanine green (ICG), which is electrostatically absorbed onto the surface of PDA, as the photothermal therapeutic agent, and the lipids modified with gadolinium-1,4,7,10-tetraacetic acid and lactobionic acid (LA), which is self-assembled on the outer surface as the shell. The LA-LAPNHs could be selectively internalized into the hepatocellular cell line (HepG2 cells) but not into HeLa cells due to the specific recognition ability of LA to asialoglycoprotein receptor. Additionally, the dual-mode imaging ability of the LA-LAPNH aqueous solution was confirmed by enhanced MR and CT imaging showing a shorter T1 relaxation time and a higher Hounsfield unit value, respectively. In addition, the LA-LAPNHs showed significant photothermal cytotoxicity against liver cancer cells with near-infrared irradiation due to their strong absorbance in the region between 700 and 850 nm. In summary, this study demonstrates that LA-LAPNHs may be a promising candidate for targeted MR/CT dual-mode imaging and photothermal therapy of hepatocellular carcinoma.

Chemiluminescence-Derived Self-Powered Photoelectrochemical Immunoassay for Detecting a Low-Abundance Disease-Related Protein

Early diagnosis of cancers relies on the sensitive detection of specific biomarkers, but most of the current testing methods are inaccessible to home healthcare due to cumbersome steps, prolonged testing time, and utilization of toxic and hazardous substances. Herein, we developed a portable self-powered photoelectrochemical (PEC) sensing platform for rapid detection of prostate-specific antigen (PSA, as a model disease-related protein) by integrating a self-powered photoelectric signal output system catalyzed with chemiluminescence-functionalized Au nanoparticles (AuNPs) and a phosphomolybdic acid (PMA)-based photochromic visualization platform. TiO₂-g-C₃N₄-PMA photosensitive materials were first synthesized and functionalized on a sensor chip. The sensor consisted of filter paper modified with a photocatalytic material and a regional laser-etched FTO electrode as an alternative to a conventional PEC sensor with a glass-based electrode. The targeting system involved a monoclonal anti-PSA capture antibody-functionalized Fe₃O₄ magnetic bead (mAb₁-MB) and a polyclonal anti-PSA antibody (pAb₂)-N-(4-aminobutyl)-N-ethylisoluminol-AuNP (ABEI-AuNP). Based on the signal intensity of the chemiluminescent system, the photochromic device color changed from light yellow to heteropoly blue through the PMA photoelectric materials integrated into the electrode for visualization of the signal output. In addition, the electrical signal in the PEC system was amplified by a sandwich-type capacitor and readout on a handheld digital multimeter. Under optimum conditions, the sensor exhibited high sensitivity relative to PSA in the range of 0.01-50 ng mL^-1 with a low detection limit of 6.25 pg mL^-1. The flow-through chemiluminescence reactor with a semiautomatic injection device and magnetic separation was avoid of unstable light source intensity inherent in the chemiluminescence process. Therefore, our strategy provides a new horizon for point-of-care analysis and rapid cost-effective clinical diagnosis.

Comprehensive Liquid Profiling of Circulating Tumor DNA and Protein Biomarkers in Long-Term Follow-Up Patients with Hepatocellular Carcinoma

PURPOSE

Circulating tumor DNA (ctDNA) provides a novel approach for detecting tumor burden and predicting clinical outcomes of hepatocellular carcinoma (HCC). Here, we performed a thorough evaluation of HCC circulating genetic features and further fully integrated them to build a robust strategy for HCC monitoring and prognostic outcome assessment.

EXPERIMENTAL DESIGN

We performed target sequencing and low-coverage whole-genome sequencing on plasma samples collected from 34 long-term follow-up patients with HCC to capture tumor somatic SNVs and CNVs, respectively. Clinical information was also obtained to evaluate the prognostic performance of ctDNA comparing with clinically applied protein biomarkers.

RESULTS

All plasma samples before surgery showed somatic genetic variations resembling corresponding tumor tissues. During follow-up, SNVs and CNVs dynamically changed correlating to patients' tumor burden. We integrated the comprehensive ctDNA mutation profiles to provide a robust strategy to accurately assess patients' tumor burden with high consistence comparing with imaging results. This strategy could discover tumor occurrence in advance of imaging for an average of 4.6 months, and showed superior performance than serum biomarkers AFP, AFP-L3%, and Des-Gamma-Carboxy Prothrombin (DCP). Furthermore, our strategy could precisely detect minimal residual disease (MRD) in advance and predict patients' prognostic outcomes for both relapse-free survival (P = 0.001) and overall survival (P = 0.001); further combining ctDNA with DCP could increase the sensitivity for MRD detection.

CONCLUSIONS

We demonstrated that plasma CNV and SNV levels dynamically correlated with patients' tumor burden in HCC. Our strategy of comprehensive mutation profile integration could accurately and better evaluate patients' prognostic risk and detect tumor occurrence in advance than traditional strategies.

Nanocluster of superparamagnetic iron oxide nanoparticles coated with poly (dopamine) for magnetic field-targeting, highly sensitive MRI and photothermal cancer therapy

In this paper, a core–shell nanocomposite of clusters of superparamagnetic iron oxide nanoparticles coated with poly(dopamine) (SPION clusters@PDA) is fabricated as a magnetic field-directed theranostic agent that combines the capabilities of highly sensitive magnetic resonance imaging (MRI) and photothermal cancer therapy. The highly concentrated SPION cluster core is suitable for sensitive MRI due to its superparamagnetic properties, and the poly(dopamine) coating layer can induce cancer cell death under near-infrared (NIR) laser irradiation because of the photothermal conversion ability of PDA. MRI scanning reveals that the nanocomposite has relatively high r2 and r2(*) relaxivities, and the r2(*) values are nearly threefold higher than the r2 values because of the clustering of the SPIONs in the nanocomposite core. Due to the rapid response to magnetic field gradients, enhanced cellular uptake of our nanocomposite mediated by an external magnetic field can be achieved, thus producing significantly enhanced local photothermal killing efficiency against cancer cells under NIR irritation.

Circular RNA profiling identifies circADAMTS13 as a miR-484 sponge which suppresses cell proliferation in hepatocellular carcinoma

Circular RNA (circRNA) can participate in various biological processes, including tumorigenesis, through their microRNA response elements. Alterations in circRNA profiles during hepatocellular carcinoma (HCC) progression and their clinical significance remain unclear. Here, we present extensive analysis of circRNA profiles in tumor and matched peritumor tissues collected from 10 HCC patients, conducted to identify circRNA related to HCC progression. A total of 42 dysregulated circRNA (38 down‐regulated and 4 up‐regulated) were identified in HCC tumor tissues compared with matched peritumor tissues, revealing the heterogeneity of circRNA profiles in HCC. CircADAMTS13, derived from Exon 13–14 of the ADAMTS13 gene, was significantly downregulated in HCC tumor tissues. Furthermore, clinicopathological analysis revealed that up‐regulation of circADAMTS13 was negatively associated with tumor size but positively associated with prognosis. In addition, overexpression of circADAMTS13 could markedly inhibit HCC cell proliferation in vitro. Bioinformatic analysis and luciferase reporter assays further revealed that circADAMTS13 directly interacts with microRNA (miR)‐484. Rescue experiments showed that miR‐484 mimics can reverse the tumor‐suppressing roles of circADAMTS13 in HCC. Therefore, our results demonstrated that circADAMTS13 can serve as a tumor suppressor during HCC progression via the functional pathway of sponging miR‐484.

Liposome-Embedded Cu2-xAgxS Nanoparticle-Mediated Photothermal Immunoassay for Daily Monitoring of cTnI Protein Using a Portable Thermal Imager

Functional photothermal nanomaterials have gained widespread attention in the field of precise cancer therapy and early disease diagnosis due to their unique photothermal conversion properties. However, the relatively narrow temperature response range and the outputable accuracy of commercial thermometers limit the accurate detection of biomarkers. Herein, we designed a liposome-embedded Cu_2-xAg_xS amplification-based photothermal sensor for the accurate determination of cardiac troponin I (cTnI) in health monitoring and point-of-care testing (POCT). The combinable 3D-printing detecting device monitored and visualized target signal changes in the testing system under the excitation of near-infrared (NIR) light, which was recorded and evaluated for possible pathogenicity by a smartphone. Notably, we predicted the potentially efficient thermal conversion efficiency of Cu_2-xAg_xS from the structure and charge density distribution, calculated by the first-principles and density functional theory (DFT), which provided a theoretical basis for the construction of novel photothermal materials, and the experimental results proved the correctness of the theoretical projections. Under optimal conditions, the photothermal immunoassay showed a dynamic linear range of 0.02-10 ng mL^-1 with a detection limit of 11.2 pg mL^-1. This work instructively introduces promising theoretical research and provides new insights for the development of sensitive portable photothermal biosensors.

Ultrasound-Driven Biomimetic Nanosystem Suppresses Tumor Growth and Metastasis through Sonodynamic Therapy, CO Therapy, and Indoleamine 2,3-Dioxygenase Inhibition

The rational design of nanoplatforms to bypass reticuloendothelial system (RES) clearance, enhance spatiotemporal controllability, and boost host immune responses to achieve synergized tumor-targeted therapeutic purpose is highly desired. Herein, a biomimetic nanosystem is developed for tumor-targeted in situ delivery of singlet oxygen (¹O₂) and carbon monoxide (CO) in response to exogenous stimulus ultrasound (US) and endogenous stimulus hydrogen peroxide (H₂O₂) in tumor microenvironment, respectively. Taking advantages of tumor homing and RES evasion abilities of the macrophage membrane coating, our designed nanosystem shows excellent accumulation at the tumor site and effective suppression of tumor growth through US/H₂O₂-generated ¹O₂ and CO to induce cell apoptosis and mitochondrial dysfunction. Furthermore, our nanosystem can induce significant tumor immunogenic death by ¹O₂/CO therapy, then can achieve effective immune responses and long-term immune memory through the combination of indoleamin 2,3-dioxygenase (IDO) signal blocking to effectively against tumor rechallenge and prevent lung metastasis. Taken together, the here-presented therapeutic strategy based on sonodynamic/CO therapy and IDO signaling inhibition might provide a promising perspective for synergistically treating cancer in future clinical translations.

Block-Polymer-Restricted Sub-nanometer Pt Nanoclusters Nanozyme-Enhanced Immunoassay for Monitoring of Cardiac Troponin I

Noble-metal nanozymes have demonstrated great potential in various fields. However, aggregation of single-particle nanoparticles severely affects their exposed catalytically active sites to the extent of exhibiting weak enzyme-like activity. Here, we present an organic block surfactant (polyvinylpyrrolidone, PVP) to construct monodisperse water-stable Pt nanoclusters (Pt NCs) for an enhanced immunoassay of cardiac troponin I (cTnI). The PVP-modified Pt NC nanozyme exhibited up to 16.3 U mg-1 peroxidase-mimicking activity, which was mainly attributed to the ligand modification on the surface and the electron-absorbing effect of the ligand on the Pt NCs. The PVP-modified Pt NCs have a lower OH-transition potential, as determined by density functional theory. Under optimized experimental conditions, the enhanced nanozyme immunoassay strategy exhibited an ultrawide dynamic response range of 0.005-50 ng mL-1 for cTnI targets with a detection limit of 1.3 pg mL-1, far superior to some reported test protocols. This work provides a designable pathway for the design of artificial enzymes with high enzyme-like activity to further expand the practical range of enzyme alternatives.

Lipid micelles packaged with semiconducting polymer dots as simultaneous MRI/photoacoustic imaging and photodynamic/photothermal dual-modal therapeutic agents for liver cancer

Semiconducting polymer dot micelles for MRI/photoacoustic imaging and single-laser-induced PDT/PTT therapy.

Circulating tumor DNA profiling reveals clonal evolution and real-time disease progression in advanced hepatocellular carcinoma

Circulating tumor DNA (ctDNA) provides a potential non-invasive biomarker for cancer diagnosis and prognosis, but whether it could reflect tumor heterogeneity and monitor therapeutic responses in hepatocellular carcinoma (HCC) is unclear. Focusing on 574 cancer genes known to harbor actionable mutations, we identified the mutation repertoire of HCC tissues, and monitored the corresponding ctDNA features in blood samples to evaluate its clinical significance. Analysis of 3 HCC patients' mutation profiles revealed that ctDNA could overcome tumor heterogeneity and provide information of tumor burden and prognosis. Further analysis was conducted on the 4th HCC case with multiple lesion samples and sequential plasma samples. We identified 160 subclonal SNVs in tumor tissues as well as matched peritumor tissues with PBMC as control. 96.9% of this patient's tissue mutations could be also detected in plasma samples. These subclonal SNVs were grouped into 9 clusters according to their trends of cellular prevalence shift in tumor tissues. Two clusters constituted of tumor stem somatic mutations showed circulating levels relating with cancer progression. Analysis of tumor somatic mutations revealed that circulating level of such tumor stem somatic mutations could reflect tumor burden and even predict prognosis earlier than traditional strategies. Furthermore, HCK (p.V174M), identified as a recurrent/metastatic related mutation site, could promote migration and invasion of HCC cells. Taken together, study of mutation profiles in biopsy and plasma samples in HCC patients showed that ctDNA could overcome tumor heterogeneity and real-time track the therapeutic responses in the longitudinal monitoring.

Tunable Competitive Absorption-Induced Signal-On Photoelectrochemical Immunoassay for Cardiac Troponin I Based on Z-Scheme Metal-Organic Framework Heterojunctions

Recently emerged Z-scheme heterostructure-based immunoassays have presented new opportunities for photoelectrochemical (PEC) biosensing development. Here, we described a tunable signal-on PEC biosensor for the detection of cardiac troponin I (cTnI), which exploited a competitive absorption effect between Cu(II) ions and a Zr metal-organic framework (Zr-MOF) constructed on TiO₂ nanorods (Cu²⁺@Zr-MOF@TiO₂ NRs). Water-stable Zr-MOF was coated onto TiO₂ NRs on fluorine-doped tin oxide to form a Z-scheme heterostructure substrate (Zr-MOF@TiO₂ NRs), which exhibited a high photoelectric response. Cu²⁺@Zr-MOF@TiO₂ NRs, constructed by loading Cu(II) ions onto the architecture of Zr-MOF by electrostatic interaction, demonstrated a low background signal. After sandwich immunorecognition within a 96-well plate, H₂S, generated by confined alkaline phosphatase on zeolitic imidazolate framework-8, was directed to react with Cu(II) ions to form CuS. This resulted in an in situ change in the photoelectrode and an enhanced photoelectric signal. The developed PEC biosensing platform exhibited high sensitivity and selectivity for the cTnI immunoassay with a detection limit of 8.6 pg/mL. The Z-scheme-based competition absorption modulation of photoelectrochemistry provides a new strategy for general PEC biosensing development.

CRISPR/Cas12a-mediated liposome-amplified strategy for the photoelectrochemical detection of nucleic acid

This study reports a photoelectrochemical biosensor for dopamine-loaded liposome-encoded magnetic beads cleaved by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas 12a system for the quantification of human papilloma virus (HPV)-related DNA using neodymium-doped BiOBr nanosheets (Nd-BiOBr) as a photoactive matrix. Magnetic beads and dopamine-loaded liposomes are covalently attached to the both ends of ssDNA to construct dumbbell-shaped dopamine-loaded liposome-encoded magnetic bead (DLL-MB) probes. When the guide RNA binds to the target HPV-16, the ssDNA will be cleaved by Cas12a, thereby degrading the double dumbbell probes. After magnetic separation, the dissolved DLLs are treated with Triton X-100 to release the dopamine (as an electron donor), which was then detected by an amplified photocurrent using the Nd-BiOBr-based photoelectrode.

Remodeling Tumor-Associated Neutrophils to Enhance Dendritic Cell-Based HCC Neoantigen Nano-Vaccine Efficiency

Hepatocellular carcinoma (HCC) commonly emerges in an immunologically "cold" state, thereafter protects it away from cytolytic attack by tumor-infiltrating lymphocytes, resulting in poor response to immunotherapy. Herein, an acidic/photo-sensitive dendritic cell (DCs)-based neoantigen nano-vaccine has been explored to convert tumor immune "cold" state into "hot", and remodel tumor-associated neutrophils to potentiate anticancer immune response for enhancing immunotherapy efficiency. The nano-vaccine is constructed by SiPCCl₂ -hybridized mesoporous silica with coordination of Fe(III)-captopril, and coating with exfoliated membrane of matured DCs by H22-specific neoantigen stimulation. The nano-vaccines actively target H22 tumors and induce immunological cell death to boost tumor-associated antigen release by the generation of excess ¹ O₂ through photodynamic therapy, which act as in situ tumor vaccination to strengthen antitumor T-cell response against primary H22 tumor growth. Interestingly, the nano-vaccines are also home to lymph nodes to directly induce the activation and proliferation of neoantigen-specific T cells to suppress the primary/distal tumor growth. Moreover, the acidic-triggered captopril release in tumor microenvironment can polarize the protumoral N2 phenotype neutrophils to antitumor N1 phenotype for improving the immune effects to achieve complete tumor regression (83%) in H22-bearing mice and prolong the survival time. This work provides an alternative approach for developing novel HCC immunotherapy strategies.

Light-Enhanced Hypoxia-Response of Conjugated Polymer Nanocarrier for Successive Synergistic Photodynamic and Chemo-Therapy

The tumor hypoxic environment as well as photodynamic therapy (PDT)-induced hypoxia could severely limit the therapeutic efficacy of traditional PDT. Fortunately, the smart integration of hypoxia-responsive drug delivery system with PDT might be a promising strategy to enhance the PDT efficiency that is hindered by the hypoxic environment. Herein, a novel azobenzene (AZO) containing conjugated polymers (CPs)-based nanocarriers (CPs-CPT-Ce6 NPs) was constructed for the combination of PDT with chemotherapy, as well as to enhance the hypoxia-responsive drug release by light. The conjugated polymer chains, used as a matrix to prepare the CPs-CPT-Ce6 NPs, were beneficial for loading hydrophobic photosensitizers and chemotherapy drugs, to improve their cellular uptake. Moreover, the AZO group (-N═N-) in CPs, which can be reduced and cleaved by azoreductase (a typical biomarker of hypoxia) under the hypoxic environment of tumor cells, acts as the hypoxia-responsive linker component. Upon laser irradiation, the CPs-CPT-Ce6 NPs could produce ROS for PDT and then facilitate the enhancement of tumor hypoxic condition, which could further promote the dissociation of CPs via reductive cleavage of AZO bridges to subsequently release cargos (chemotherapeutic drug, CPT) and then significantly enhance the killing effects to tumor cells that were resistant to PDT. Both in vitro and in vivo studies confirmed the improvement of synergistic therapeutic effects of our CPs-CPT-Ce6 NPs. This cascade responsive approach provides an excellent complementary mode for PDT and could open new insights for constructing programmable and controllable responsive systems in biomedical applications.

Photoinduced Electron Transfer Modulated Photoelectric Signal: Toward an Organic Small Molecule-Based Photoelectrochemical Platform for Formaldehyde Detection

Photoelectrochemical (PEC) sensing has been rapidly evolving in recent years, while the introduction of small molecules with specific recognition functions into the sensing interface remains a nascent area of study. In this work, we reported a PEC biosensor for formaldehyde (FA) detection based on photoinduced electron transfer (PET)-gated electron injection between organic small molecules and inorganic semiconducting substrates. Specifically, an FA-responsive probe (NA-FA-COOH) and TiO₂ nanoarrays were integrated to construct a PEC platform (NFC/TiO₂) via a coordination bond. NFC served simultaneously as a target-specific recognition element and a modulator of photoinduced electron injection. Treatment of NFC/TiO₂ by FA would suppress the intramolecular PET process, with the quenched photocurrent signal due to the changed carrier transfer pathway, thus establishing the PEC platform for FA based on effective PET modulation. The proposed PEC system exhibited high selectivity and sensitivity, with a low detection limit of 0.071 μM. This study presents a novel perspective on the use of organic small molecules with a PET effect for advanced PEC bioanalysis.

Personalized neoantigen vaccine prevents postoperative recurrence in hepatocellular carcinoma patients with vascular invasion

Background

Clinically, prophylactic anti-recurrence treatments for hepatocellular carcinoma (HCC) patients after radical surgery are extremely limited. Neoantigen based vaccine can generate robust anti-tumor immune response in several solid tumors but whether it could induce anti-tumor immune response in HCC and serve as a safe and effective prophylactic strategy for preventing postoperative HCC recurrence still remain largely unclear.

Methods

Personalized neoantigen vaccine was designed and immunized for 10 HCC patients with high risk of postoperative recurrence in a prime-boost schedule. The safety and immune response were assessed through adverse events, tissue sequencing, ELISpot, TCR sequencing. The clinical response was evaluated by recurrence-free survival (RFS) and personalized circulating tumor DNA (ctDNA) sequencing.

Results

In the 10 enrolled patients, no obvious adverse events were observed during neoantigen vaccinations. Until the deadline of clinical trial, 8 of 10 patients were confirmed with clinical relapse by imaging, the other 2 patients remained relapse-free. From receiving first neoantigen vaccination, the median RFS of 10 patients were 7.4 months. Among 7 patients received all planned neoantigen vaccinations, 5 of them demonstrated neoantigen-induced T cell responses and have significantly longer RFS after radical surgery than other 5 patients without responsive neoantigens or only with prime vaccination and propensity scores matching control patients (p = 0.035). Moreover, tracking personalized neoantigen mutations in ctDNA could provide real-time evaluation of clinical response in HCC patients during neoantigen vaccination and follow up.

Conclusion

Personalized neoantigen vaccine is proved as a safe, feasible and effective strategy for HCC anti-recurrence, and its progression could be sensitively monitored by corresponding neoantigen mutations in ctDNA, and thus provided solid information for individualized medicine in HCC.

Trial registration

This study was registered at Chinese Clinical Trial Registry; Registration number: ChiCTR1900020990.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01467-8.

Antioxidants inhibit cell senescence and preserve stemness of adipose tissue-derived stem cells by reducing ROS generation during long-term in vitro expansion

BACKGROUND

Adipose tissue-derived mesenchymal stem cells (ADSCs) are promising candidates for regenerative medicine. However, long-term in vitro passaging leads to stemness loss and cell senescence of ADSCs, resulting in failure of ADSC-based therapy.

METHODS

In this study, ADSCs were treated with low dose of antioxidants (reduced glutathione and melatonin) with anti-aging and stem cell protection properties in the in vitro passaging, and the cell functions including stem cell senescence, cell migration, cell multidirectional differentiation potential, and ROS content were carefully analyzed.

RESULTS

We found that GSH and melatonin could maintain ADSC cell functions through reducing cell senescence and promoting cell migration, as well as by preserving stemness and multidirectional differentiation potential, through inhibiting ROS generation during long-term expansion of ADSCs.

CONCLUSIONS

Our results suggested that antioxidant treatment could efficiently prevent the dysfunction and preserve cell functions of ADSCs after long-term passaging, providing a practical strategy to facilitate ADSC-based therapy.

Photocatalysis Enhancement for Programmable Killing of Hepatocellular Carcinoma through Self-Compensation Mechanisms Based on Black Phosphorus Quantum-Dot-Hybridized Nanocatalysts

Recently reported black phosphorus quantum dots (BPQDs) possess unique photocatalysis activities. However, the environmental instability accompanied by a hypoxic tumor microenvironment (TME) seriously hindered the bioapplications of BPQDs, especially in oxygen-dependent photodynamic therapy (PDT). Here, we construct a hepatocellular carcinoma (HCC)-specific targeting aptamer "TLS11a"-decorated BPQDs-hybridized nanocatalyst, which can specifically target HCC tumor cells and self-compensate oxygen (O₂) into hypoxic TME for enhancing PDT efficiency. The BPQD-hybridized mesoporous silica framework (BMSF) with in situ synthesized Pt nanoparticles (PtNPs) in the BMSF is simply prepared. After being decorated by TLS11a aptamer/Mal-PEG-NHS, the resultant nanosystem (refer as Apt-BMSF@Pt) exhibits excellent environmental stability, active targeting ability to HCC cells, and self-compensation ability of oxygen. Compared with the PEG-BMSF@Pt without H₂O₂ incubation, the PEG-BMSF@Pt nanocatalyst exhibits 4.2-folds O₂ and 1.6-folds ¹O₂ generation ability in a mimetic closed-system in the presence of both H₂O₂ and near-infrared laser. In a mouse model, the Apt-BMSF@Pt can effectively accumulate into tumor sites, and the core of BMSF subsequently can act as a photosensitizer to generate reactive oxygen species, while the PtNPs can serve as a catalyst to convert H₂O₂ into O₂ for enhancing PDT through self-compensation mechanisms in hypoxic TME. By comparison of the tumor volume/weight, H&E, and immunohistochemical analysis, the excellent antitumor effects with minimized side effects of our Apt-BMSF@Pt could be demonstrated in vivo. Taken together, the current study suggests that our Apt-BMSF@Pt could act as an active targeting nanocatalyst for programmable killing of cancer cells in hypoxic TME.

Glypican-3 antibody functionalized Prussian blue nanoparticles for targeted MR imaging and photothermal therapy of hepatocellular carcinoma

MRI-guided photothermal therapy is becoming a more widely accepted minimally invasive technique.