Multimodal Golden DNA Superstructures (GDSs) for Highly Efficient Photothermal Immunotherapy

DNA-templated metallization has emerged as an efficient strategy for creating nanoscale-metal DNA hybrid structures with a desirable conformation and function. Despite the potential of DNA-metal hybrids, their use as combinatory therapeutic agents has rarely been examined. Herein, we present a simple approach for fabricating a multipurpose DNA superstructure that serves as an efficient photoimmunotherapy agent. Specifically, we adsorb and locally concentrate Au ions onto DNA superstructures through induced local reduction, resulting in the formation of Au nanoclusters. The mechanical and optical properties of these metallic nanoclusters can be rationally controlled by their conformations and metal ions. The resulting golden DNA superstructures (GDSs) exhibit significant photothermal effects that induce cancer cell apoptosis. When sequence-specific immunostimulatory effects of DNA are combined, GDSs provide a synergistic effect to eradicate cancer and inhibit metastasis, demonstrating potential as a combinatory therapeutic agent for tumor treatment. Altogether, the DNA superstructure-templated metal casting system offers promising materials for future biomedical applications.

Low- and high-volume blood-flow restriction treadmill walking both improve maximal aerobic capacity independently of blood volume

AIM

Assess the effect of low- and high-volume blood flow restriction training (BFR) on maximal aerobic capacity (VO2 max) and determine if alteration in VO2 max is mediated through changes in hemoglobin mass (Hbmass) and blood volume.

METHODS

Participants' Hbmass (CO-rebreathe), single, and double-leg VO2 max and blood volume regulating hormonal responses (renin and copeptin) were measured before and after BFR training. Training consisted of treadmill walking either (1) twice-daily for 4week (CON and BFRHV ) or (2) twice-weekly for 6week (BFRLV ). Each session consisted of five intervals (3 min, 5% incline, 5 km/h, 100% of lowest occlusion pressure), with 1 min of standing rest between sets.

RESULTS

VO2 max increased using both training exposures, in as quickly as 2-weeks (BFRLV baseline to 4week: +315 ± 241 mL (8.7%), p = 0.02; BFRHV baseline to 2week: +360 ± 261 mL (7.9%), p < 0.01), for the BFRLV and BFRHV groups, with no change in CON. Single- and double-leg VO2 max improved proportionately (single/double-leg VO2 max ratio: BFRLV 78 ± 4.9-78 ± 5.8%, BFRHV 79 ± 6.5-77 ± 6.5%), suggesting that the mechanism for increased VO2 max is not solely limited to central or peripheral adaptations. Hbmass remained unchanged across groups (CON: +10.2 ± 34 g, BFRLV : +6.6 ± 42 g, BFRHV : +3.2 ± 44 g; p = 0.9), despite a significant release of blood volume regulating hormones after initial BFR exposure (renin +20.8 ± 21.9 ng/L, p < 0.01; copeptin +22.0 ± 23.8 pmol/L, p < 0.01), which was blunted following BFRHV training (renin: +13.4 ± 12.4 ng/L, p = 0.09; copeptin: +1.9 ± 1.7 pmol/L, p = 0.98).

CONCLUSION

BFR treadmill walking increases VO2 max irrespective of changes in Hbmass or blood volume despite a large release of blood volume regulating hormones in response to BFR treadmill walking.

Therapeutic Extracellular Vesicles from Tonsil-Derived Mesenchymal Stem Cells for the Treatment of Retinal Degenerative Disease

BACKGROUND

Retinal degenerative disease (RDD), one of the most common causes of blindness, is predominantly caused by the gradual death of retinal pigment epithelial cells (RPEs) and photoreceptors due to various causes. Cell-based therapies, such as stem cell implantation, have been developed for the treatment of RDD, but potential risks, including teratogenicity and immune reactions, have hampered their clinical application. Stem cell-derived extracellular vesicles (EVs) have recently emerged as a cell-free alternative therapeutic strategy; however, additional invasiveness and low yield of the stem cell extraction process is problematic.

METHODS

To overcome these limitations, we developed therapeutic EVs for the treatment of RDD which were extracted from tonsil-derived mesenchymal stem cells obtained from human tonsil tissue discarded as medical waste following tonsillectomy (T-MSC EVs). To verify the biocompatibility and cytoprotective effect of T-MSC EVs, we measured cell viability by co-culture with human RPE without or with toxic all-trans-retinal. To elucidate the cytoprotective mechanism of T-MSC EVs, we performed transcriptome sequencing using RNA extracted from RPEs. The in vivo protective effect of T-MSC EVs was evaluated using Pde6b gene knockout rats as an animal model of retinitis pigmentosa.

RESULTS

T-MSC EVs showed high biocompatibility and the human pigment epithelial cells were significantly protected in the presence of T-MSC EVs from the toxic effect of all-trans-retinal. In addition, T-MSC EVs showed a dose-dependent cell death-delaying effect in real-time quantification of cell death. Transcriptome sequencing analysis revealed that the efficient ability of T-MSC EVs to regulate intracellular oxidative stress may be one of the reasons explaining their excellent cytoprotective effect. Additionally, intravitreally injected T-MSC EVs had an inhibitory effect on the destruction of the outer nuclear layer in the Pde6b gene knockout rat.

CONCLUSIONS

Together, the results of this study indicate the preventive and therapeutic effects of T-MSC EVs during the initiation and development of retinal degeneration, which may be a beneficial alternative for the treatment of RDD.

Self-assembly of a multimeric genomic hydrogel via multi-primed chain reaction of dual single-stranded circular plasmids for cell-free protein production

Recent technical advances in cell-free protein synthesis (CFPS) offer several advantages over cell-based expression systems, including the application of cellular machinery, such as transcription and translation, in the test tube. Inspired by the advantages of CFPS, we have fabricated a multimeric genomic DNA hydrogel (mGD-gel) via rolling circle chain amplification (RCCA) using dual single-stranded circular plasmids with multiple primers. The mGD-gel exhibited significantly enhanced protein yield. In addition, mGD-gel can be reused at least five times, and the shape of the mGD-gel can be easily manipulated without losing the feasibility of protein expression. The mGD-gel platform based on the self-assembly of multimeric genomic DNA strands (mGD strands) has the potential to be used in CFPS systems for a variety of biotechnological applications.

Healthcare workers' epidemiology of occupational exposure to blood-borne viruses, post-exposure prophylaxis, and seroconversion over 10 years

BACKGROUND

Healthcare workers (HCWs) have an increased risk of blood-borne pathogen (BBP) infection due to occupational blood exposures (OBEs). Early reporting, detection, and post-exposure prophylaxis (PEP) allows for prevention of infections.

AIM

To investigate the incidence of OBEs, related epidemiological characteristics, PEP completion rate, time and reason for PEP discontinuation, and seroconversion rate reported over 10 years.

METHODS

We retrospectively analysed 1,086 OBE cases and staff PEP management from January 2012 to December 2021 in a South Korean tertiary hospital.

FINDINGS

The mean incidence of OBE was 7.82 per 100 beds and 3.0 per 100 HCWs. Among 1,086 cases, 633 (58.3%) required PEP, and 453 (41.7%) did not. After OBEs, 70.1% (444/633) of those subject to PEP completed tracking, and 29.9% (189/633) stopped PEP tracking (p < 0.001). The PEP completion rate showed a significant difference according to gender (p = 0.024), occupation (p < 0.001), and exposure frequency (p < 0.001). None of the 444 HCWs who completed PEP seroconverted to hepatitis B virus, hepatitis C virus, human immunodeficiency virus, or Treponema pallidum (syphilis).

CONCLUSION

Our findings demonstrate the need to improve follow-up care among HCWs following OBEs. There is a need for education in healthcare facilities; moreover, establishing a national surveillance system is necessary to ensure that HCWs proactively undergo PEP and complete their follow-up visits.

RADIOLOGICAL IMPACT OF USING DECORATIVE GRANITE AS AN ATTENUATOR OF IONIZING RADIATION

Granite is a widely available rock, which can be used as a shielding material, for bulk in the form of the aggregate in concrete. It has the weakness that it is more radioactive than many other rocks, which can be used in concrete. This paper looks at its properties as a shielding material and the activity level. Thus, the concentrations of 226Ra, 232Th and 40K, in granite were measured using a high pure germanium detector (HPGe). They were ranged from (15 ± 4 to 49 ± 5) Bq kg-1 for 226Ra, (22 ± 4 to 78 ± 4 Bq kg-1) for 232Th and (791 ± 13 to 1231 ± 15 Bq kg-1) for 40K. Radiological indices of radium equivalent concentration (Raeq), external (Hex), internal (Hin) and annual effective dose were less than worldwide recommended limits. The results emphasized, the granite samples had no radiation hazard. Nevertheless, the mass attenuation coefficients of granite samples were measured for the gamma rays of energy range 122-1408 keV. The mass attenuation coefficients of the studied granite samples were ranged from 0.05 to 0.15 cm2 g-1. In addition, the average the half-value layer of granite was varied from 1.8 cm for 122 keV to 5.2 cm for 1408 keV. The results are that the attenuation characteristics are typical and match the values given by NIST for 'concrete' and that the activity levels of the samples examined are acceptable. Thus the granite may be used as an attenuator for ionizing radiation.

The efficacy of immune checkpoint inhibitors in elderly patients: a meta-analysis and meta-regression

Background

Immune checkpoint inhibitor (ICI) therapy has improved patient survival in advanced cancers; however, the efficacy of ICIs in elderly patients is still elusive. This study assessed the efficacy of ICIs in elderly patients with advanced cancer in terms of overall survival (OS) and progression-free survival (PFS).

Materials and methods

We carried out a systematic review and identified 30 head-to-head phase II/III randomized controlled trials that compared immunotherapy with the standard of care in advanced solid tumor patients. The data on patients younger or over 65 years of age were indexed from PubMed-Medline, Embase, and Scopus and obtained for meta-analysis. The subgroup analyses were stratified by primary tumor type, line of treatment, or type of immunotherapy, and a meta-regression analysis was carried out after adjusting for all other variables.

Results

The study included 17 476 patients, comprising 58% (10 119) younger (<65 years old) and 42% (7357) elderly (≥65 years old) patients. The hazard ratio (HR) for OS was 0.77 [95% confidence interval (CI) 0.70-0.85] and 0.77 (95% CI 0.70-0.85) in the younger and elderly groups, respectively, suggesting similar efficacies of ICIs in these two age groups. The subgroup analyses revealed no significant relationship between age and treatment outcomes, except for the PFS benefit in younger patients with melanoma than in elderly patients (HR 0.44 in younger patients versus 0.65 in elderly patients, P = 0.04). These results were further supported by meta-regression analysis, which showed no statistically significant difference in OS (P = 0.954) and PFS (P = 0.555) between the two age groups.

Conclusions

The findings suggest that age-associated impairments of the immune system did not affect the efficacy of ICIs in elderly patients compared to younger patients. Therefore, the choice of ICIs for elderly patients can be considered, regardless of chronological age.

•

We evaluated the efficacy of ICI in 17 476 patients, comprising 58% younger and 42% elderly patients.

•

Meta-analysis resulted in the comparable efficacy of ICI between younger and older age groups.

•

Further, meta-regression analysis showed no significant difference in OS and PFS.

•

Our study suggests that chronological age does not lead to immunosenescence in response to ICI in immune-oncology.

The effect of an isolation-coping programme on patients isolated for colonization or infection with multidrug-resistant organisms: a quasi-experimental study

BACKGROUND

The global increase in the prevalence of vancomycin-resistant enterococci (VRE) and carbapenem-resistant Enterobacterales (CRE) among multidrug-resistant organisms (MDROs) has necessitated contact precaution and isolation in medical institutions. Contact isolation has a negative effect on the mental health of patients, but few interventions have addressed this issue.

AIM

This study evaluated an isolation-coping programme developed for patients colonized or infected with VRE or CRE.

METHODS

To mitigate the negative effects of isolation due to having MDRO, an infection control nurse in the present study 1) developed an isolation-coping programme and 2) validated the programme's effect on the uncertainty, anxiety, depression, and knowledge of patients isolated because of MDRO (VRE or CRE) using a pre-post quasi-experimental design.

FINDINGS

The experimental group (n=56) received education and emotional support via the isolation-coping programme, while the control group (n=55) received only verbal isolation guidelines provided by the medical institution. Compared with the control group, the experimental group showed a reduction in uncertainty (t=-8.925), anxiety (Z=-6.131), and depression (Z=-5.379), and better knowledge (Z=-8.372) (p<.001 for all).

CONCLUSION

The novel isolation-coping programme is an effective intervention to improve uncertainty, anxiety, depression, and knowledge in patients isolated with VRE or CRE.

Multimeric RNAs for efficient RNA-based therapeutics and vaccines

There has been a growing interest in RNA therapeutics globally, and much progress has been made in this area, which has been further accelerated by the clinical applications of RNA-based vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Following these successful clinical trials, various technologies have been developed to improve the efficacy of RNA-based drugs. Multimerization of RNA therapeutics is one of the most attractive approaches to ensure high stability, high efficacy, and prolonged action of RNA-based drugs. In this review, we offer an overview of the representative approaches for generating repetitive functional RNAs by chemical conjugation, structural self-assembly, enzymatic elongation, and self-amplification. The therapeutic and vaccine applications of engineered multimeric RNAs in various diseases have also been summarized. By outlining the current status of multimeric RNAs, the potential of multimeric RNA as a promising treatment strategy is highlighted.

DNA Optoelectronics: Versatile Systems for On-Demand Functional Electrochemical Applications

Herein, we propose innovative deoxyribonucleic acid (DNA)-based gels and their applications in diverse optoelectronics. We prepared the optoelectronic DNA-based gels (^OpDNA Gel) through molecular complexation, that is, groove binding and ionic interactions of DNA and 1,1'-diheptyl-4,4'-bipyridinium (DHV). This process is feasible even with sequence-nonspecific DNA extracted from nature (e.g., salmon testes), resulting in the expansion of the application scope of DNA-based gels. ^OpDNA Gel possessed good mechanical characteristics (e.g., high compressibility, thermoplasticity, and outstanding viscoelastic properties) that have not been observed in typical DNA hydrogels. Moreover, the electrochromic (EC) characteristics of DHV were not lost when combined with ^OpDNA Gel. By taking advantage of the facile moldability, voltage-tunable EC behavior, and biocompatibility/biodegradability of ^OpDNA Gel, we successfully demonstrated its applicability in a variety of functional electrochemical systems, including on-demand information coding systems, user-customized EC displays, and microorganism monitoring systems. The ^OpDNA Gel is a promising platform for the application of DNA-based biomaterials in electrochemical optoelectronics.

Construction of a two-dimensional DNA-RNA hybridized membrane for collecting tumor-derived exosomes

Macroscopic nucleic acid-based structures have attracted much attention in biomedical fields. Here, we introduce a novel DNA-RNA hybridized membrane structure via enzymatic dual polymerization. The membrane exhibited enhanced rigidity and functionality. Encoded with an aptamer, the membrane showed great potential as a collecting platform of tumor-derived exosomes without additional labeling.

RNA polymerization actuating nucleic acid membrane (RANAM)-based biosensing for universal RNA virus detection

The coronavirus disease (COVID-19) pandemic has shown the importance of early disease diagnosis in preventing further infection and mortality. Despite major advances in the development of highly precise and rapid detection approaches, the time-consuming process of designing a virus-specific diagnostic kit has been a limiting factor in the early management of the pandemic. Here, we propose an RNA polymerase activity-sensing strategy utilizing an RNA polymerization actuating nucleic acid membrane (RANAM) partially metallized with gold for colorimetric RNA virus detection. Following RANAM-templated amplification of newly synthesized RNA, the presence of the RNA polymerase was determined by visualization of the inhibition of an oxidation/reduction (redox) reaction between 3,3′,5,5′-tetramethylbenzidine (TMB) and blocked Au³⁺. As a proof of concept, a viral RNA-dependent RNA polymerase (RdRP), which is found in various RNA virus-infected cells, was chosen as a target molecule. With this novel RANAM biosensor, as little as 10 min of RdRP incubation could significantly reduce the colorimetric signal. Further development into an easy-to-use prototype kit in viral infection diagnosis detected RdRP present at levels even as low as 100 aM. Color formation based on the presence of RdRP could be simply and clearly confirmed through smartphone-assisted color imaging of the prototype kit. This study provides a non-PCR-based RNA virus detection including its variants using RdRP-mediated polymerization.

Systemic CXCL10 is a predictive biomarker of vitiligo lesional skin infiltration, PUVA, NB-UVB and corticosteroid treatment response and outcome

Vitiligo is an acquired pigmentary skin disorder that currently lacks standardized treatment and validated biomarkers to objectively evaluate disease state or therapeutic response. Although prior studies have linked vitiligo autoimmunity with CXCL10/CXCL9-mediated recruitment of leukocytes to the skin, only limited clinical data are available regarding CXCL10 as vitiligo biomarker. To evaluate the utility of systemic CXCL10 as a predictor of disease progression and treatment response on a large cohort of vitiligo patients. CXCL10 levels in lesional, perilesional, and unaffected skin of vitiligo patient (n = 30) and in the serum (n = 51) were measured by quantitative ELISA. CXCL10 expression, recruitment of leukocytes, and inflammatory infiltrates were evaluated by histochemical (n = 32) and immunofluorescence (n = 10) staining. Rigorous cross-sectional and longitudinal biostatistical analysis were employed to correlate CXCL10 levels with disease variables, treatment response, and outcome. We demonstrated that elevated CXCL10 level (2 pg/mm² and higher) in lesional skin correlates with increased leukocytic infiltrate, disease duration (< 2 year), and its higher level in the serum (50 pg/ml and higher). Changes in CXCL10 serum levels in patients treated with psoralen plus UVA (PUVA) phototherapy, narrowband UVB (NB-UVB) phototherapy, and systemic steroids (SS) correlated with changes in the intralesional CXCL10 levels in repigmented skin. NB-UVB and SS regimens provided most consistent CXCL10 mean change, suggesting that these regimens are most effective in harnessing CXCR3-mediated inflammatory response. Serum CXCL10 is a useful vitiligo biomarker, which predicts lesional skin leukocytic infiltration, and vitiligo treatment response and outcome.

Astrocyte-derived extracellular vesicles enhance the survival and electrophysiological function of human cortical neurons in vitro

Neurons derived from human induced pluripotent stem cells (hiPSCs) are powerful tools for modeling neural pathophysiology and preclinical efficacy/toxicity screening of novel therapeutic compounds. However, human neurons cultured in vitro typically do not fully recapitulate the physiology of the human nervous system, especially in terms of exhibiting morphological maturation, longevity, and electrochemical signaling ability comparable to that of adult human neurons. In this study, we investigated the potential for astrocyte-derived extracellular vesicles (EVs) to modulate survival and electrophysiological function of human neurons in vitro. Specifically, we demonstrate that EVs obtained from human astrocytes promote enhanced single cell electrophysiological function and anti-apoptotic behavior in a homogeneous population of human iPSC-derived cortical neurons. Furthermore, EV-proteomic analysis was performed to identify cargo proteins with the potential to promote the physiological enhancement observed. EV cargos were found to include neuroprotective proteins such as heat shock proteins, alpha-synuclein, and lipoprotein receptor-related protein 1 (LRP1), as well as apolipoprotein E (APOE), which negatively regulates neuronal apoptosis, and a peroxidasin homolog that supports neuronal oxidative stress management. Proteins that positively regulate neuronal excitability and synaptic development were also detected, such as potassium channel tetramerization domain containing 12 (KCTD12), glucose-6- phosphate dehydrogenase (G6PD), kinesin family member 5B (KIF5B), spectrin-alpha non-erythrocytic1 (SPTAN1). The remarkable improvements in electrophysiological function and evident inhibition of apoptotic signaling in cultured neurons exposed to these cargos may hold significance for improving preclinical in vitro screening modalities. In addition, our collected data highlight the potential for EV-based therapeutics as a potential class of future clinical treatment for tackling inveterate central and peripheral neuropathies.

Viscosity-Regulated Control of RNA Microstructure Fabrication

The development of RNA self-assemblies offers a powerful platform for a wide range of biomedical applications. The fabrication process has become more elaborate in order to achieve functional structures with maximized potential. As a facile means to control the structure, here, we report a new approach to manipulate the polymerization rate and subsequent self-assembly process through regulation of the reaction viscosity. As the RNA polymerization rate has a dependence on solution viscosity, the resulting assembly, crystallization, and overall sizes of the product could be manipulated. The simple and precise control of RNA polymerization and self-assembly by reaction viscosity will provide a way to widen the utility of RNA-based materials.

Rapid Diagnosis of Coronavirus by RNA-Directed RNA Transcription Using an Engineered RNA-based Platform

A coronavirus disease (COVID-19) outbreak associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading widely through person-to-person transmission. Various detection approaches have been developed involving quantitative polymerase chain reaction (qPCR) methods, CRISPR-based systems, and direct targeting of specific coronavirus proteins. However, there have only been a few reports on the detection of RNA-dependent RNA polymerase (RdRP), the primer-independent RNA-replicable protein produced by the RNA genes of coronavirus. Here, we introduce a novel diagnostic methodology for COVID-19 using the RNA-directed and de novo RNA replicable function of RdRP. We devised an RNA platform for RdRP-induced transcription (RPRIT) that includes an RNA template that can be directly transcribed by RdRP. By utilizing RPRIT, the presence of RdRP can be readily confirmed within 30 min using isothermal incubation without PCR. This RdRP detection method can provide a new route for rapid diagnosis of RNA virus-infected patients.

Double Controlled Release of Therapeutic RNA Modules through Injectable DNA-RNA Hybrid Hydrogel

Advances in the DNA nanotechnology have enabled the fabrication of DNA-based hydrogels with precisely controlled structures and tunable mechanical and biological properties. Compared to DNA hydrogel, preparation of RNA-based hydrogel remains challenging due to the inherent instability of naked RNA. To overcome these limitations, we fabricated a DNA-RNA hybrid hydrogel via stepwise dual enzymatic polymerization. Multimeric short hairpin RNAs (shRNAs) were hybridized with functional DNA aptamers for targeting and mechanical properties of the hydrogel. The obtained DNA-RNA hybrid hydrogel was ultrasoft, robust, and injectable hence reconfigurable into any confined structures. As a model system, the hydrogel was able to mimic microtubule structures under physiological conditions and designed to release the functional small interfering RNA (siRNA)-aptamer complex (SAC) sequentially. In addition, we encoded restriction enzyme-responsive sites in DNA-RNA hybrid hydrogel to boost the release of SAC. This novel strategy provides an excellent platform for systematic RNA delivery through double-controlled release, SAC release from hydrogel, and subsequent release of siRNA from the SAC, which has promising potential in RNA therapy.

Quality Evaluation of Mobile Applications for Fine dust Management

Background

Recently, the use of fine dust management mobile applications has been on the rise in South Korea. The aim of this study is to describe the current status of fine dust and air pollution mhealth apps used in Korea and to make qualitative assessments of them.

Methods

App search contents analysis 400 apps were searched using PM2.5, PM10 and yellow dust, the main keywords related to fine dust, referring to the preceding reference from December 30, 2019 to January 2, 2020. Among the apps searched, apps that meet all six criteria, such as those with 1) user score ≥4.0, 2) n of review Top 50, 3) those that do not duplicated, 4) apps that are related to the topic, 5) apps set in Korean, and 6) apps that do not have errors, were selected for the study. App assessment The app evaluation of the study utilizes the MARS scale, an app assessment tool developed overseas. The assessment was conducted for a week from January 3, 2020 to January 10, 2020. Each of the apps averaged scores evaluated over a week for each category and averaged over five categories for an overall quality score.

Results

The standard deviation of the information and functionality of the 30 apps was similar, with 3.62 (SD 0.38) and 3.58 (SD 0.43), respectively. On the other hand, engagement was the lowest with an average of 3.1 (SD 0.44). The average of aesthetics was 3.4 (SD 0.64), indicating that deviations between apps were very large

Conclusions

It is deemed necessary to improve the user interface (UI) and configuration of the app to enhance the application's engagement and aesthetics in order to increase the use of fine dust apps by consumers and gain effect.

Key messages

This research provided information that consumers can reasonably use and select mobile health apps by evaluating and reviewing the contents of fine dust and air pollution mobile health apps. this study is important in that it can serve as a reference for app developers to consider in future app development.

An enzymatically self-assembled DNA patch for enhanced blood coagulation

The assembly of a DNA patch combining enzymatically fabricated DNA film and aptamer-based thrombin binding for enhanced blood coagulation is demonstrated.

BRC-mediated RNAi targeting of USE1 inhibits tumor growth in vitro and in vivo

USE1 has been demonstrated to play crucial roles in the development and progression of human lung cancer. However, the antitumor efficacy of RNA interference (RNAi) targeting of USE1 has not yet been evaluated as a possible clinical application. We here synthesized USE1 targeting bubbled RNA-based cargo (BRC) composed of densely packed multimeric pre-siRNAs with specific Dicer cleavage sites to enable efficient siRNA release upon entry to target cells. The physical entanglement and continuous networking of RNAs via hybridization during enzymatic replication serve as a driving force for the self-assembly of BRCs. These molecules effectively suppressed the transcription of their target genes, leading to tumor growth suppression in vitro and in vivo. Moreover, their repeated intravenous administration efficiently inhibited the growth of A549 tumor xenografts. Based on these findings of a reduced cancer cell viability following a USE1 knockdown, we further explored cell cycle arrest and apoptosis pathways. The observed tumor cell growth suppression was found to be controlled by cell cycle arrest and apoptosis signals induced by the USE1 reduction. These results suggest that USE1 BRCs may have future clinical applications as an RNAi-based cancer therapy.

Engineered extracellular vesicles and their mimetics for clinical translation

Cells secrete extracellular vesicles (EVs) to external environments to achieve cellular homeostasis and cell-to-cell communication. Their therapeutic potential has been constantly spotlighted since they mirror both cytoplasmic and membranous components of parental cells. Meanwhile, growing evidence suggests that EV engineering could further promote EVs with a maximized capacity. In this review, a range of engineering techniques as well as upscaling approaches to exploit EVs and their mimetics are introduced. By laying out the pros and cons of each technique from different perspectives, we sought to provide an overview potentially helpful for understanding the current state of the art EV engineering and a guideline for choosing a suitable technique for engineering EVs. Furthermore, we envision that the advances in each technique will give rise to the combinatorial engineering of EVs, taking us a step closer to a clinical translation of EV-based therapeutics.

Self-assembled DNA hollow spheres from microsponges

We report a novel approach for generating nanosized DNA hollow spheres (HSs) using enzymatically produced DNA microsponges in a self-templating manner. In previous studies, preparation of DNA nanostructures with specified functions required multiple complicated steps. In this study, however, a simple treatment with the nucleophilic agent 4-dimethylaminopyridine (DMAP) enabled a gradual disentanglement of DNA in microsponges by electrostatic interactions between DMAP and DNA, and the DNA underwent a reassembly process to generate hollow shell structures without denaturation/annealing by thermal cycling. In addition, this synthetic process was conducted in a water-based system without organic solvents, enabling the synthesis of biologically and environmentally friendly products. Based on the benefits of hollow shell structures, which include their high surface-to-volume ratio and ability to encapsulate small molecules, we envision that this simple approach for synthesizing DNA HSs will provide a new platform for maximizing their potential use in drug delivery and bio-imaging.

Immunostimulatory Effects Triggered by Self-Assembled Microspheres with Tandem Repeats of Polymerized RNA Strands

Self-assembled RNA particles have been exploited widely to maximize the therapeutic potential of RNA. However, the immune response via RNA particles is not fully understood. In addition, the investigation of the immunogenicity from RNA-based particles is required owing to inherent immunostimulatory effects of RNA for clinical translation. To examine the immune stimulating potency, rationally designed microsized RNA particles, called RNA microspheres (RMSs), are generated with single or double strands via rolling circle transcription. The RMSs show an exceptional stability in the presence of serum, while they are selectively degraded under endolysosomal conditions. With precisely controlled size, both RMSs are successfully taken up by macrophages. Unlike the nature of RNA fragments, RMSs induce only basal-level expression of inflammatory cytokines as well as type I interferon from macrophages, suggesting that RMSs are immunocompatible in the therapeutic dose range. Taken together, this study could help accelerate clinical translation and broaden the applicability of the self-assembled RNA-based particles without being limited by their potential immunotoxicity, while a systematic controllability study observing the release of RNA fragments from RMSs would provide self-assembled RNA-based structures with a great potential for immunomodulation.

Correction: CpG incorporated DNA microparticles for elevated immune stimulation for antigen presenting cells

Correction for ‘CpG incorporated DNA microparticles for elevated immune stimulation for antigen presenting cells’ by Heejung Jung et al., RSC Adv., 2018, 8, 6608–6615.

Infusion of ex-vivo expanded human TCR-αβ+ double-negative regulatory T cells delays onset of xenogeneic graft-versus-host disease

Despite the demonstration of potent immunosuppressive function of T cell receptor (TCR)-αβ⁺ double-negative regulatory T cells (DN T_regs ), scarce numbers and lack of effective expansion method limit their clinical applications. Here we describe an approach that allows for ∼3500-fold ex-vivo expansion of human DN T_regs within 3 weeks with > 97% purity. Ex-vivo-expanded DN T_regs suppress proliferation of polyclonally stimulated autologous T and B cells in vitro through direct cell-to-cell contact. In vivo, we demonstrate for the first time that infusion of human DN T_regs delayed an onset of xenogeneic graft-versus-host disease (GVHD) significantly in a humanized mouse model. Furthermore, preincubation of ex-vivo-expanded DN T_regs with a mechanistic target of rapamycin (mTOR) inhibitor rapamycin enhanced their immune regulatory function further. Taken together, this study demonstrates that human DN T_regs can be expanded ex vivo to therapeutic numbers. The expanded DN T_regs can suppress proliferation of T and B cells and attenuate GVHD, highlighting the potential clinical use of DN T_regs to mitigate GVHD.

Size-Controllable Enzymatic Synthesis of Short Hairpin RNA Nanoparticles by Controlling the Rate of RNA Polymerization

Thanks to a wide range of biological functions of RNA, and advancements in nanotechnology, RNA nanotechnology has developed in multiple ways for RNA-based therapeutics. In particular, among RNA engineering techniques, enzymatic self-assembly of RNA structures has gained great attention for its high packing density of RNA, with a low cost and one-pot synthetic process. However, manipulation of the overall size of particles, especially a reduction in size, has not been studied in depth. Here, we reported the enzymatic self-assembly of short hairpin RNA particles for the downregulation of target genes, and a rational approach to the manipulation of the resultant particle size. This is the first report of the size-controllable enzymatic self-assembly of short hairpin RNA nanoparticles. While keeping all the benefits of an enzymatic approach, the overall size of the RNA particles was controlled on a scale of 2 μm to 100 nm, falling within the therapeutically applicable size range.

Skin photorejuvenation effects of light-emitting diodes (LEDs): a comparative study of yellow and red LEDs in vitro and in vivo

BACKGROUND

Red-coloured light-emitting diodes (LEDs) can improve skin photorejuvenation and regeneration by increasing cellular metabolic activity.

AIM

To evaluate the effectiveness of visible LEDs with specific wavelengths for skin photorejuvenation in vitro and in vivo.

METHODS

Normal human dermal fibroblasts (HDFs) from neonatal foreskin were cultured and irradiated in vitro by LEDs at different wavelengths (410-850 nm) and doses (0-10 J/cm(2) ). In vivo experiments were performed on the skin of hairless mice. Expression of collagen (COL) and matrix metalloproteinases (MMPs) was evaluated by semi-quantitative reverse transcription PCR (semi-qRT-PCR), western blotting and a procollagen type I C-peptide enzyme immunoassay (EIA). Haematoxylin and eosin and Masson trichrome stains were performed to evaluate histological changes.

RESULTS

In HDFs, COL I was upregulated and MMP-1 was downregulated in response to LED irradiation at 595 ± 2 and 630 ± 8 nm. In the EIA, a peak result was achieved at a dose of 5 J/cm(2) with LED at 595 ± 2 nm. In vivo, COL I synthesis was upregulated in a dose-dependent manner to both 595 and 630 nm LED irradiation, and this effect was prolonged to 21 days after a single irradiation with a dose of 100 J/cm(2) . These histological changes were consistent with the results of semi-qRT-PCR and western blots.

CONCLUSION

Specific LED treatment with 595 ± 2 and 630 ± 8 nm irradiation was able to modulate COL and MMPs in skin, with the effects persisting for at least 21 days after irradiation. These findings suggest that yellow and red LEDs might be useful tools for skin photorejuvenation.

Reversibility of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication - a prospective study for up to 10 years

BACKGROUND

Atrophic gastritis and intestinal metaplasia are premalignant conditions for gastric cancer. Their reversibility by Helicobacter pylori eradication remains controversial.

AIM

To evaluate the reversibility of atrophic gastritis and intestinal metaplasia by H. pylori eradication with long-term follow-up.

METHODS

598 subjects were prospectively enrolled and followed for up to 10 years. They were categorised as H. pylori-negative (n = 65), H. pylori non-eradicated (n = 91), and H. pylori-eradicated (n = 442). Histological assessment was performed for antrum and corpus by Sydney classification.

RESULTS

Histological follow-up was performed regularly at 1, 2, 3-4 and ≥5 years, with mean follow-up of 1.07 ± 0.21, 2.29 ± 0.83, 3.93 ± 1.02, and 6.45 ± 1.28 years, respectively. Atrophic gastritis in antrum and corpus gradually and significantly (both P < .05 for all timepoints) improved only in the H. pylori-eradicated group compared to that at baseline. Significant difference in atrophic gastritis between H. pylori-eradicated and H. pylori-negative groups disappeared from 1-year follow-up. Similarly, intestinal metaplasia in antrum and corpus improved significantly (both P < .05 for all timepoints) only in the H. pylori-eradicated group in comparison with that at baseline. Significant difference in intestinal metaplasia between H. pylori-eradicated and H. pylori-negative groups disappeared from ≥5 years of follow-up in the antrum and from 3 years of follow-up in the corpus.

CONCLUSION

H. pylori eradication may be a preventative strategy for intestinal-type gastric cancer by regression of atrophic gastritis and intestinal metaplasia.

A Novel Technique for Cervical Laminoplasty Fusion: Simultaneously Enhancing Stabilization and Decompression in Various Cervical Myelopathies: A Technical Note and Outcomes

BACKGROUND

Cervical laminectomy has 2 major disadvantages: postlaminectomy adhesion of dural membrane and lack of a fusion bed. The objective of this study was to determine whether simultaneous cervical laminoplasty with fusion (CLPF) might overcome these unwanted outcomes.

METHODS

Patients who underwent CLPF for treating cervical myelopathy with instability who were followed up for at least 12 months were enrolled. Preoperative and postoperative Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) scores before and after surgery, recovery rates (RRs), C2-C7 lordosis, and fusion success rates were evaluated.

RESULTS

The study cohort comprised 50 patients (35 males and 15 females; mean age, 60.5 ± 14.0 years) who underwent CLPF. The average duration of clinical follow-up was 24.6 ± 16.1 months. Mean preoperative and postoperative NDI scores were 27.0 ± 10.6 and 17.6 ± 7.2, respectively (P = 0.004). Mean preoperative and postoperative JOA scores were 10.4 ± 4.2 and 13.6 ± 3.0, respectively (P = 0.001). The mean JOA RR was 49.8 ± 42.2%. No significant changes in C2-7 lordosis were noted after surgery (preoperative, 7.0 ± 8.0°; postoperative, 7.3 ± 6.3°; P = 0.789). The fusion success rate was 96% (48 of 50 patients). Fusion mass areas at C5 level were significantly different between the opening side and the hinge side (opening side, 15.8 ± 13.1 mm²; hinge side, 50.8 ± 27.2 mm²; P < 0.001). There was no postoperative restenosis or epidural fibrosis.

CONCLUSIONS

CLPF might be useful for canal decompression and a good fusion bed while avoiding postoperative epidural fibrosis.

CpG incorporated DNA microparticles for elevated immune stimulation for antigen presenting cells

As emerging evidence supports the immune stimulating capability of the CpG oligodeoxynucleotides (ODN), CpG-based adjuvants have been widely used. For efficient induction of immune responses, current issues affecting the use of nucleic acid-based adjuvants, e.g. stability in physiological conditions, delivery to immune cells, and successful release within the phagolysosome, should be addressed. Here, we present CpG-based DNA microparticles (DNA-MPs) fabricated by complementary rolling circle amplification (cRCA) as adjuvants for enhancing immune response and production of selective antibody production. Using cRCA method, the sizes of CpG-based DNA-MPs were finely controlled (0.5 and 1 μm) with superior and provided mismatched single stranded form of CpG ODN region for specific cleavage site by DNase II within the phagolysosome. Fabricated CpG-based 1 μm DNA-MPs (DNA-MP-1.0) were successfully internalized into primary macrophages and macrophage cell line (RAW264.7 cells), and elicited superior cytokine production e.g. TNF-α and IL-6, compared to conventional CpG ODNs. After in vivo administration of DNA-MP-1.0 with model antigen ovalbumin (OVA), significantly elevated OVA-specific antibody production was observed. With this in mind, DNA-MP-1.0 could serve as a novel type of adjuvant for the activation of macrophages and the following production of selective antibodies without any noticeable toxicity in vitro and in vivo.

As emerging evidence supports the immune stimulating capability of the CpG oligodeoxynucleotides (ODN), CpG-based adjuvants have been widely used.

Therapeutic effects of a novel siRNA-based anti-VEGF (siVEGF) nanoball for the treatment of choroidal neovascularization

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries and is characterized by the development of choroidal neovascularization (CNV). Therapies for AMD have focused on suppressing angiogenic factors, such as vascular endothelial growth factor (VEGF), mainly via conventional anti-VEGF antibody agents. However, additional efforts have been made to develop effective small-interfering RNA (siRNA)-based intracellular therapeutic agents. In this study, we have manufactured a novel siRNA-based anti-VEGF nanoball (siVEGF NB). The siVEGF NB was composed of a siRNA hydrogel with a core of anti-VEGF sequence siRNA coated with branched PEI (bPEI) and hyaluronic acid (HA) in order by applying an electrical force. The novel siVEGF NBs, which were employed in a laser-induced CNV mouse model, were optimized as a retinal and choroidal delivery system through the vitreous humor to the sub-retinal space via CD44 receptor endocytosis on the inner limiting membrane, and showed therapeutic effects via pathways bypassing the TLR3-induced siRNA-class effect. The therapeutic effects of siVEGF NBs lasted for 2 weeks after intravitreal injection showing high targeting efficiency to the sub-retinal space. Thus, the newly developed siVEGF NB may have great potential for the delivery of RNAi-based therapeutics for ocular diseases, including AMD.

Synthesis of a multi-functional DNA nanosphere barcode system for direct cell detection

Nucleic acid-based technologies have been applied to numerous biomedical applications. As a novel material for target detection, DNA has been used to construct a barcode system with a range of structures. This paper reports multi-functionalized DNA nanospheres (DNANSs) by rolling circle amplification (RCA) with several functionalized nucleotides. DNANSs with a barcode system were designed to exhibit fluorescence for coding enhanced signals and contain biotin for more functionalities, including targeting through the biotin-streptavidin (biotin-STA) interaction. Functionalized deoxynucleotide triphosphates (dNTPs) were mixed in the RCA process and functional moieties can be expressed on the DNANSs. The anti-epidermal growth factor receptor antibodies (anti-EGFR Abs) can be conjugated on DNANSs for targeting cancer cells specifically. As a proof of concept, the potential of the multi-functional DNANS barcode was demonstrated by direct cell detection as a simple detection method. The DNANS barcode provides a new route for the simple and rapid selective recognition of cancer cells.

Library siRNA-generating RNA nanosponges for gene silencing by complementary rolling circle transcription

Since the discovery of RNA interference (RNAi), small interfering RNA (siRNA) has been powerful tools for gene downregulation in biomedical applications. Despite the outstanding efficacy of siRNA, the development of a therapeutic delivery system remains a challenge owing to the instability of RNA. In this study, we describe a new method for the design of siRNA-generating nanosponges by using complementary rolling circle transcription (cRCT), a technique that requires two complementary circular DNA. The sequences of one of the circular DNA are designed to have complete complementarity to the target mRNA resulting in double stranded RNA (dsRNA) that can be digested to siRNA by cellular Dicer activity. This siRNA design, called 'library siRNA', could be universally applied to fabricate RNA nanosponges targeting any known mRNA sequence.

Bubbled RNA-Based Cargo for Boosting RNA Interference

As ribonucleic acid (RNA) nanotechnology has advanced, it has been applied widely in RNA-based therapeutics. Among the range of approaches, enzymatically synthesized RNA structures for inducing RNA interference in cancer cells have potential for silencing genes in a target-specific manner. On the other hand, the efficiency of gene silencing needs to be improved to utilize the RNA-based system for RNAi therapeutics. This paper introduces a new approach for efficient generation of siRNA from bubbled RNA-based cargo (BRC). The presence of bubbles in between to avoid nonfunctional short dsRNAs allows the RNA-based cargoes to contain multiple Dicer-cleavage sites to release the functional siRNAs when introduced to cells. BRCs can be synthesized easily in a one-pot process and be purified by simple centrifugation. Furthermore, efficient target gene silencing by the bubbled structure is confirmed both in vitro and in vivo. Therefore, this bubbled RNA cargo system can be utilized for target-specific RNAi therapeutics with high efficiency in the generation of functional siRNAs in the target cells.

Error rate of automated calculation for wound surface area using a digital photography

BACKGROUND

Although measuring would size using digital photography is a quick and simple method to evaluate the skin wound, the possible compatibility of it has not been fully validated.

PURPOSE

To investigate the error rate of our newly developed wound surface area calculation using digital photography.

METHODS

Using a smartphone and a digital single lens reflex (DSLR) camera, four photographs of various sized wounds (diameter: 0.5-3.5 cm) were taken from the facial skin model in company with color patches. The quantitative values of wound areas were automatically calculated. The relative error (RE) of this method with regard to wound sizes and types of camera was analyzed.

RESULTS

RE of individual calculated area was from 0.0329% (DSLR, diameter 1.0 cm) to 23.7166% (smartphone, diameter 2.0 cm). In spite of the correction of lens curvature, smartphone has significantly higher error rate than DSLR camera (3.9431±2.9772 vs 8.1303±4.8236). However, in cases of wound diameter below than 3 cm, REs of average values of four photographs were below than 5%. In addition, there was no difference in the average value of wound area taken by smartphone and DSLR camera in those cases.

CONCLUSION

For the follow-up of small skin defect (diameter: <3 cm), our newly developed automated wound area calculation method is able to be applied to the plenty of photographs, and the average values of them are a relatively useful index of wound healing with acceptable error rate.

Optimization of electrospun fibrous membranes for in vitro modeling of blood-brain barrier

The blood-brain barrier (BBB) plays a critical role in brain homeostasis at the cellular and global level. Mimicking the selective permeability and transport properties of the BBB to specific molecules and cells remains a significant challenge towards the development of a physiologically relevant in vitro BBB model. In this study, we developed electrospun poly (ε-caprolactone) (PCL) and polyethylene glycol (PEG) copolymer membranes that supported different cellular components of the neurovascular unit including human-derived endothelial cells, pericytes and astrocytes. Comparative analyses of thickness, morphology, biocompatibility and permeability of membranes were also conducted. We found that collagen coated 4%PEG-96%PCL membranes supported the growth of a confluent and tight endothelium confirmed by transendothelial electrical resistance measurements (TEER). Based on fabrication process and reported results, we finally discuss the adoption of these electrospun fiber membranes for in vitro and on-a-chip human BBB models.

A biomaterial approach to cell reprogramming and differentiation

Cell reprogramming of somatic cells into pluripotent states and subsequent differentiation into certain phenotypes has helped progress regenerative medicine research and other medical applications. Recent research has used viral vectors to induce this reprogramming; however, limitations include low efficiency and safety concerns. In this review, we discuss how biomaterial methods offer potential avenues for either increasing viability and downstream applicability of viral methods, or providing a safer alternative. The use of non-viral delivery systems, such as electroporation, micro/nanoparticles, nucleic acids and the modulation of culture substrate topography and stiffness have generated valuable insights regarding cell reprogramming.

Poly-sgRNA/siRNA ribonucleoprotein nanoparticles for targeted gene disruption

Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein-9 nuclease (Cas9) can be used for the specific disruption of a target gene to permanently suppress the expression of the protein encoded by the target gene. Efficient delivery of the system to an intracellular target site should be achieved to utilize the tremendous potential of the genome-editing tool in biomedical applications such as the knock-out of disease-related genes and the correction of defect genes. Here, we devise polymeric CRISPR/Cas9 system based on poly-ribonucleoprotein (RNP) nanoparticles consisting of polymeric sgRNA, siRNA, and Cas9 endonuclease in order to improve the delivery efficiency. When delivered by cationic lipids, the RNP nanoparticles built with chimeric poly-sgRNA/siRNA sequences generate multiple sgRNA-Cas9 RNP complexes upon the Dicer-mediated digestion of the siRNA parts, leading to more efficient disruption of the target gene in cells and animal models, compared with the monomeric sgRNA-Cas9 RNP complex.

DNA aptamer-based carrier for loading proteins and enhancing the enzymatic activity

Here, we synthesized DNA microparticles comprised of thrombin binding aptamers via rolling circle amplification (RCA). These DNA aptamer particles could successfully load a number of thrombins and the complexes have shown improved thrombin activity.

Giant Catalytic DNA Particles for Simple and Intuitive Detection of Pb(2.)

DNAzymes have been extensively studied as biosensors because of their unique functionality of cleaving substrate in the presence of metal ion cofactors. However, there are only a few reports on visual detection using gold nanoparticles. Here, we synthesized the DNAzyme microparticle (DzMP) (~1 μm) via rolling circle amplification for detection of Pb(2+) without the help of other materials. Then, the substrate strands were labeled with two different fluorophores (6-carboxyfluorescein and Cy5) to visualize the DzMPs and to monitor the separation of substrate strands. Because of their large size, the decline in the number of fluorescent particles in the presence of Pb(2+) could be successfully demonstrated by a fluorescence microscopy, presenting a new platform for heavy metal detection.

RCA-Based Biosensor for Electrical and Colorimetric Detection of Pathogen DNA

For the diagnosis and prevention of diseases, a range of strategies for the detection of pathogens have been developed. In this study, we synthesized the rolling circle amplification (RCA)-based biosensor that enables detection of pathogen DNA in two analytical modes. Only in the presence of the target DNA, the template DNA can be continuously polymerized by simply carrying out RCA, which gives rise to a change of surface structure of Au electrodes and the gap between the electrodes. Electrical signal was generated after introducing hydrogen tetrachloroaurate (HAuCl4) to the DNA-coated biosensor for the improvement of the conductivity of DNA, which indicates that the presence of the pathogen DNA can be detected in an electrical approach. Furthermore, the existence of the target DNA was readily detected by the naked eyes through change in colors of the electrodes from bright yellow to orange-red after RCA reaction. The RCA-based biosensor offers a new platform for monitoring of pathogenic DNA with two different detection modes in one system.

Technological development of structural DNA/RNA-based RNAi systems and their applications

RNA interference (RNAi)-based gene therapy has drawn tremendous attention due to its highly specific gene regulation by selective degradation of any target mRNA. There have been multiple reports regarding the development of various cationic materials for efficient siRNA delivery, however, many studies still suffer from the conventional delivery problems such as suboptimal transfection performance, a lack of tissue specificity, and potential cytotoxicity. Despite the huge therapeutic potential of siRNAs, conventional gene carriers have failed to guarantee successful gene silencing in vivo, thus not warranting clinical trials. The relatively short double-stranded structure of siRNAs has resulted in uncompromising delivery formulations, as well as low transfection efficiency, compared with the conventional nucleic acid drugs such as plasmid DNAs. Recent developments in structural siRNA and RNAi nanotechnology have enabled more refined and reliable in vivo gene silencing with multiple advantages over naked siRNAs. This review focuses on recent progress in the development of structural DNA/RNA-based RNAi systems and their potential therapeutic applications. In addition, an extensive list of prior reports on various RNAi systems is provided and categorized by their distinctive molecular characters.

Lymph node size is not a reliable criterion for predicting nodal metastasis in rectal neuroendocrine tumours

AIM

The study was designed to assess the correlation between lymph node (LN) size and LN metastasis in patients with rectal neuroendocrine tumours (NETs).

METHOD

Forty patients who underwent curative resection with lymphadenectomy for a rectal NET between January 2007 and December 2012 were included. The short and long diameters of entire nodes were microscopically measured using a slide gauge.

RESULTS

In all, 1052 LNs were collected from the 40 patients, with 49 (4.7%) showing evidence of metastasis. Metastasis-positive LNs had significantly greater long and short diameters (P < 0.001) than metastasis-negative LNs. Of the 49 metastatic LNs, 29 (59.2%) were ≤ 5 mm in largest diameter. In five patients, the largest metastatic LN was only 2-3 mm in diameter. In clinically node-negative (cN0) patients, 18 (51.4%) patients had metastatic LNs (pN1).

CONCLUSION

The size of LNs containing metastasis varied widely, with some being very small. LN size alone is therefore not a sufficient predictor of tumour metastasis in rectal NETs. Radical surgery with lymphadenectomy should be considered for patients with rectal NETs with high risk factors for LN metastasis, even those without LN enlargement.