LncRNA PCED1B-AS1 mediates miR-3681-3p/MAP2K7 axis to promote metastasis, invasion and EMT in gastric cancer.

BACKGROUND: LncRNA PCED1B-AS1 is abnormally expressed in multiple cancers and has been confirmed as an oncogene. Our study aimed to investigate the regulatory mechanism of lncRNA PCED1B-AS1 in gastric cancer. METHODS: TCGA database was used to analyze the abnormal expression of lncRNA PCED1B-AS1 in gastric cancer. By database prediction and mass spectrometric analysis, miR-3681-3p and MAP2K7 are potential downstream target molecules of lncRNA PCED1B-AS1 and verified by dual-luciferase report assay. RT-qPCR analysis and western blot were performed to detect the expressions of PCED1B-AS1 and MAP2K7 in gastric cancer cell lines and tissues. CCK-8 kit was applied to measure the cell viability. Wound healing and Transwell experiment were used to detect the migration and invasion. Western blot and immunohistochemical staining were performed to detect the expressions of EMT-related proteins in tissues. The changes of tumor proliferation were detected by xenograft experiment in nude mice. RESULTS: PCED1B-AS1 expression was higher but miR-3681-3 expression was lower in gastric cancer cell lines or tissues, compared to normal group. Function analysis verified PCED1B-AS1 promoted cell proliferation and inhibited cell apoptosis in gastric cancer cells in vitro and in vivo. LncRNA PCED1B-AS1 could bind directly to miR-3681-3p, and MAP2K7 was found to be a downstream target of miR-3681-3p. MiR-3681-3p mimics or si-MAP2K7 could partly reverse the effect of PCED1B-AS1 on gastric cancer cells. CONCLUSION: PCED1B-AS1 accelerated cell proliferation and inhibited cell apoptosis through sponging miR-3681-3p to upregulate MAP2K7 expression in gastric cancer, which indicated PCED1B-AS1/miR-3681-3p/MAP2K7 axis may serve as a potential therapeutic target for gastric cancer.

Smartphone-enabled colorimetric immunoassay for deoxynivalenol based on Mn2+-mediated aggregation of AuNPs.

Deoxynivalenol (DON) is a common mycotoxin in food that mainly pollutes grain crops and feeds, such as barley, wheat and corn. DON has caused widespread concern in the field of food and feed safety. In this study, a colorimetric immunoassay was proposed based on the aggregation of gold nanoparticles (AuNPs) due to the decomposition of Mn2+ from gold-coated manganese dioxide (AuNP@MnO2) nanosheets. In this study, 2-(dihydrogen phosphate)-l-ascorbic acid (AAP) was hydrolyzed by alkaline phosphatase (ALP) and converted to ascorbic acid (AA). Then, AuNP@MnO2 was reduced to Mn2+ and AuNPs aggregation occurred. Using the unique optical characteristics of AuNPs and AuNP@MnO2, visible color changes realized simple detection of DON with high sensitivity and portability. With increasing DON content, the color changed more obviously. To quantitatively detect DON, pictures can be taken and the blue value can be read by a smartphone. The detection limit (Ic10) of this method was 0.098 ng mL-1, which was 326 times higher than that of traditional competitive ELISA, and the detection range was 0.177-6.073 ng mL-1. This method exhibited high specificity with no cross-reaction in other structural analogs. The average recovery rate of DON in corn flour samples was 89.1 %-110.2 %, demonstrating the high accuracy and stability of this assay in actual sample detection. Therefore, the colorimetric immunoassay can be used for DON-related food safety monitoring.

Artificial intelligence-assisted system for the assessment of Forrest classification of peptic ulcer bleeding: a multicenter diagnostic study.

BACKGROUND: Inaccurate Forrest classification may significantly affect clinical outcomes, especially in high risk patients. Therefore, this study aimed to develop a real-time deep convolutional neural network (DCNN) system to assess the Forrest classification of peptic ulcer bleeding (PUB). METHODS: A training dataset (3868 endoscopic images) and an internal validation dataset (834 images) were retrospectively collected from the 900th Hospital, Fuzhou, China. In addition, 521 images collected from four other hospitals were used for external validation. Finally, 46 endoscopic videos were prospectively collected to assess the real-time diagnostic performance of the DCNN system, whose diagnostic performance was also prospectively compared with that of three senior and three junior endoscopists. RESULTS: The DCNN system had a satisfactory diagnostic performance in the assessment of Forrest classification, with an accuracy of 91.2% (95%CI 89.5%-92.6%) and a macro-average area under the receiver operating characteristic curve of 0.80 in the validation dataset. Moreover, the DCNN system could judge suspicious regions automatically using Forrest classification in real-time videos, with an accuracy of 92.0% (95%CI 80.8%-97.8%). The DCNN system showed more accurate and stable diagnostic performance than endoscopists in the prospective clinical comparison test. This system helped to slightly improve the diagnostic performance of senior endoscopists and considerably enhance that of junior endoscopists. CONCLUSION: The DCNN system for the assessment of the Forrest classification of PUB showed satisfactory diagnostic performance, which was slightly superior to that of senior endoscopists. It could therefore effectively assist junior endoscopists in making such diagnoses during gastroscopy.

Artificial intelligence-aided diagnostic imaging: A state-of-the-art technique in precancerous screening.

BACKGROUND AND AIM: Chromoendoscopy with the use of indigo carmine (IC) dye is a crucial endoscopic technique to identify gastrointestinal neoplasms. However, its performance is limited by the endoscopist's skill, and no standards are available for lesion identification. Thus, we developed an artificial intelligence (AI) model to replace chromoendoscopy. METHODS: This pilot study assessed the feasibility of our novel AI model in the conversion of white-light images (WLI) into virtual IC-dyed images based on a generative adversarial network. The predictions of our AI model were evaluated against the assessments of five endoscopic experts who were blinded to the purpose of this study with a staining quality rating from 1 (unacceptable) to 4 (excellent). RESULTS: The AI model successfully transformed the WLI of polyps with different morphologies and different types of lesions in the gastrointestinal tract into virtual IC-dyed images. The quality ratings of the real IC-dyed and AI images did not significantly differ concerning surface structure (AI vs IC: 3.08 vs 3.00), lesion border (3.04 vs 2.98), and overall contrast (3.14 vs 3.02) from 10 sets of images (10 AI images and 10 real IC-dyed images). Although the score depended significantly on the evaluator, the staining methods (AI or real IC) and evaluators had no significant interaction (P > 0.05) with each other. CONCLUSION: Our results demonstrated the feasibility of employing AI model's virtual IC staining, increasing the possibility of being employed in daily practice. This novel technology may facilitate gastrointestinal lesion identification in the future.

Immunosuppressive Ability of Trichinella spiralis Adults Can Ameliorate Type 2 Inflammation in a Murine Allergy Model.

BACKGROUND: There is an increase in the global incidence of allergies. The hygiene hypothesis and the old friend hypothesis reveal that helminths are associated with the prevalence of allergic diseases. The therapeutic potential of Trichinella spiralis is recognized; however, the stage at which it exerts its immunomodulatory effect is unclear. METHODS: We evaluated the differentiation of bone marrow-derived macrophages stimulated with T spiralis excretory-secretory products. Based on an ovalbumin-induced murine model, T spiralis was introduced during 3 allergy phases. Cytokine levels and immune cell subsets in the lung, spleen, and peritoneal cavity were assessed. RESULTS: We found that T spiralis infection reduced lung inflammation, increased anti-inflammatory cytokines, and decreased Th2 cytokines and alarms. Recruitment of eosinophils, CD11b+ dendritic cells, and interstitial macrophages to the lung was significantly suppressed, whereas Treg cells and alternatively activated macrophages increased in T spiralis infection groups vs the ovalbumin group. Notably, when T spiralis was infected prior to ovalbumin challenge, intestinal adults promoted proportions of CD103+ dendritic cells and alveolar macrophages. CONCLUSIONS: T spiralis strongly suppressed type 2 inflammation, and adults maintained lung immune homeostasis.

Eimeria granulosa causes spots visible through the serous membrane of small intestine in sheep.

Coccidiosis, also known as Eimeriosis, is a highly prevalent parasitic disease affecting sheep in nearly all sheep-rearing nations across the globe. Currently, there is a scarcity of literature documenting the specific lesions in sheep resulting from coccidia infection. This study aimed to investigate these characteristic lesions through necropsy, microscopic observation, and molecular biological techniques. As a result, Eimeria granulosa was identified as the causative agent, which induced distinct pathological alterations in the small intestine of lambs as observed during necropsy. Notably, E. granulosa manifested as small scattered petechiae and white spots, visible through the serous membrane of the small intestine, akin to the pathology observed in E. necatrix. Therefore, this study provides valuable insights for the accurate diagnosis of coccidiosis in sheep.

m6A-related lncRNAs predict prognosis and indicate cell cycle in gastric cancer.

Background: N6-methyladenosine (m6A) modification is a common epigenetic methylation modification of RNA, which plays an important role in gastric carcinogenesis and progression by regulating long non-coding RNA (lncRNA). This study is aimed to investigate the potential prognostic signatures of m6A -related lncRNAs in STAD. Methods: The m6A-related lncRNAs with the most significant impact on gastric cancer prognosis in the TCGA database were identified by bioinformatics and machine learning methods. The m6A-related lncRNA prognostic model (m6A-LPS) and nomogram was constructed by Cox regression analysis with the minimum absolute contraction and selection operator (LASSO) algorithm. The functional enrichment analysis of m6A-related lncRNAs was also investigated. The miRTarBase, miRDB and TargetScan databases were utilized to establish a prognosis-related network of competing endogenous RNA (ceRNA) by bioinformatics methods. The correlation of AL391152.1 expressions and cell cycle were experimentally testified by qRT-PCR and flow cytometry. Results: In total, 697 lncRNAs that were identified as m6A-related lncRNAs in GC samples. The survival analysis showed that 18 lncRNAs demonstrated prognostic values. A risk model with 11 lncRNAs was established by Lasso Cox regression, and can predict the prognosis of GC patients. Cox regression analysis and ROC curve indicated that this lncRNA prediction model was an independent risk factor for survival rates. Functional enrichment analysis and ceRNA network revealed that the nomogram was notably associated with cell cycle. qRT-PCR and flow cytometry revealed that downregulation of GC m6A-related lncRNA AL391152.1 could decrease cyclins expression in SGC7901 cells. Conclusion: A m6A-related lncRNAs prognostic model was established in this study, which can be applied to predict prognosis and cell cycle in gastric cancer.

TACC diagnosed by transoesophageal endoscopic ultrasonography: A case report.

BACKGROUND: Primary adenoid cystic carcinoma in the trachea (TACC) is a rare tumour. Tracheal bronchoscopy is always chosen as a routine approach to obtain a pathological diagnosis, but it can be associated with an increased risk of asphyxia. CASE SUMMARY: We describe a case of TACC in a patient evaluated by chest computed tomography (CT) with three-dimensional reconstruction imaging and diagnosed by transoesophageal endoscopic ultrasonography. The pathological diagnosis confirmed tracheal adenoid cystic carcinoma. CONCLUSION: We highlight the importance of CT and provide a successful exploration of transoesophageal biopsy as a safe alternative approach.

The continuing discovery on the evidence for RNA editing in SARS-CoV-2.

Recent studies have presented strong evidence that C-to-U RNA editing is the driving force that fuels severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolution. The findings finally ended the long-term debate on the evolutionary driving force behind SARS-CoV-2 evolution. Here, we would first acknowledge the breakthroughs made by the recent works, such as using the global SARS-CoV-2 data to demonstrate the major mutation source of this virus. Meanwhile, we would raise a few concerns on the accuracy of their interpretation on C-to-U RNA editing. By re-analysing the SARS-CoV-2 population data, we found that the editing frequency on C-to-U sites did not perfectly correlate with the binding motif of the editing enzyme APOBEC, suggesting that there might be false-positive sites among the C-to-U mutations or the original data did not fully represent the novel mutation rate. We hope our work could help people understand the molecular basis underlying SARS-CoV-2 mutation and also be useful to guide future studies on SARS-CoV-2 evolution.

Superficial Flat-Type Early-Stage Gastric Signet Ring Cell Carcinoma in the Atrophic Background Mucosa: Two Case Reports.

OBJECTIVES: Gastric signet ring cell carcinoma is a rare and highly malignant adenocarcinoma, which is characterized by early metastasis, rapid progression and poor prognosis. Several studies have shown that early-stage gastric signet ring cell carcinoma may have equal or better prognosis than other types of gastric cancer. However, most of the early-stage lesions are difficult to detect by endoscopy. We aim to illustrate the difficulty of early detection of gastric signet ring cell carcinoma with mucosal atrophy. METHODS: The endoscopic and pathological features of two female cases were analyzed by upper gastrointestinal white light endoscopy combined with narrow-band imaging and endoscopic biopsy. RESULTS: Two female cases were diagnosed with early-stage gastric signet ring cell carcinoma with atrophic background mucosa occurring in the middle and lower part of the stomach. Both lesions less than 2.0 cm in diameter were surgically removed and identified as intramucosal adenocarcinoma. CONCLUSION: We can roughly identify the demarcation of the lesion by combining white light endoscopy and narrow-band imaging, and slightly irregular microsurface and microvascular pattern of the lesion were found via magnifying endoscopic observation, but the demarcation can hardly be accurately identified.

The influences of timing of urgent endoscopy in patients with acute variceal bleeding: a cohort study.

BACKGROUND: There has always been a debate on the optimal timing of endoscopy in patients with acute variceal bleeding (AVB). OBJECTIVE: This study aimed to examine the relation between the timing of endoscopy and the short-term outcomes of patients with AVB. METHODS: Patients with AVB who underwent endoscopy within 24 h after admission at our tertiary care center from 2014 to 2022 were evaluated retrospectively. The primary outcomes were the 6-week mortality and re-bleeding. The secondary outcomes included the total number of blood units transfused, the length of hospital stay, and the need for salvage therapy. We used Cox proportional hazards model to analyze the predictors of 6-week mortality in all patients as well as in those who were at high risk of further bleeding or death. RESULTS: A total of 312 patients were enrolled. Among them, 170 patients (54.49%) underwent urgent endoscopy (< 6 h), and 142 patients (45.51%) underwent early endoscopy (6-24 h). There were no significant differences between the urgent-endoscopy group and the early-endoscopy group, regarding the 6-week mortality (16.47% vs. 10.56%; P value = 0.132) and 6-week re-bleeding rate (11.2% vs. 16.2%; P value = 0.196). In multivariate analysis, time to endoscopy was independent of 6-week mortality (P value = 0.170), but the time between the beginning of bleeding and endoscopy (within 12 h) was significantly associated with low 6-week mortality (OR: 0.16; 95% CI: 0.06-0.46; P value = 0.001). Time to endoscopy was still not associated with 6-week mortality in patients at high risk for further bleeding or death (Glasgow-Blatchford score ≥ 12, n = 138, P value = 0.902). CONCLUSIONS: Endoscopy performed within 6 h of admission, rather than within 6 to 24 h, did not improve six-week clinical outcomes in patients in stable condition with AVB and even those who were at high risk of further bleeding and death.

A mucosal recovery software tool for endoscopic submucosal dissection in early gastric cancer.

Background: Due to the limited diagnostic ability, the low detection rate of early gastric cancer (EGC) is a serious health threat. The establishment of the mapping between endoscopic images and pathological images can rapidly improve the diagnostic ability to detect EGC. To expedite the learning process of EGC diagnosis, a mucosal recovery map for the mapping between ESD mucosa specimen and pathological images should be performed in collaboration with endoscopists and pathologists, which is a time-consuming and laborious work. Methods: 20 patients at the Zhejiang Provincial People's Hospital, Affiliated People's Hospital of Hangzhou Medical College from March 2020 to July 2020 were enrolled in this study. We proposed the improved U-Net to obtain WSI-level segmentation results, and the WSI-level results can be mapped to the macroscopic image of the specimen. For the convenient use, a software pipeline named as "Pathology Helper" for integration the workflow of the construction of mucosal recovery maps was developed. Results: The MIoU and Dice of our model can achieve 0.955 ± 0.0936 and 0.961 ± 0.0874 for WSI-level segmentation, respectively. With the help of "Pathology Helper", we can construct the high-quality mucosal recovery maps to reduce the workload of endoscopists and pathologists. Conclusion: "Pathology Helper" will accelerate the learning of endoscopists and pathologists, and rapidly improve their abilities to detect EGC. Our work can also improve the detection rate of early gastric cancer, so that more patients with gastric cancer will be treated in a timely manner.

A New Preparation Method for Peroral Endoscopic Myotomy in Patients with Achalasia Can Effectively Reduce the Esophageal Residual Contents: A Comparative Retrospective Study.

METHODS: This retrospective study enrolled 65 achalasia patients who underwent POEM from June 2017 to October 2021. Based on the preoperative diet strategies, patients were divided into carbonated beverage group (n = 48) and control group (n = 17). Demographic and clinical data, duration of preoperative endoscopy, quality of esophagus cleansing, and patient satisfaction on preoperative procedure were collected and compared. In the current study, we established the quality of esophagus cleansing: Grade A, no remnants or only liquid or frothy discharge; Grade B, a little amount of solid content remained; and Grade C, a large amount of solid content remained. RESULTS: There were 41 Grade A, 6 Grade B, and 1 Grade C patients in the carbonated beverage group, while there were 8 Grade A, 6 Grade B, and 3 Grade C patients in the control group (p value = 0.001). The esophagus cleansing degrees were significantly ameliorated after drinking carbonated beverages in all the three subtypes of achalasia according to the degree of dilatation. The mean duration of preoperative endoscopy was 6.54 ± 2.250 minutes in the carbonated beverage group and 10.27 ± 4.788 minutes in the control group (p value = 0.010). The score of patient satisfaction concerning the procedure before the POEM in the carbonated beverage group was 4.5 ± 0.652, while the score in the control group was 4.35 ± 0.702 (p value = 0.436). In the multivariate analysis, patient satisfaction was significantly associated with male (odds ratio 0.296, 95% CI: 0.097-0.905, p value = 0.033). CONCLUSIONS: Drinking carbonated beverages reduce the duration of preoperative endoscopy and ameliorate the esophagus cleansing degrees without impairing patient satisfaction.

Novel endoscopic tangential sawing technique in treatment of giant gastric bezoars: a retrospective single-center study (with video).

BACKGROUND AND AIMS: The current methods for treatment of giant gastric bezoars mainly include chemical dissolution, endoscopic fragmentation, and surgical removal, which often have limited curative effects or generate multiple adverse events. Therefore, there is an urgent need to find new methods to overcome such a dilemma. The aim of this study was to evaluate the safety, efficacy, and feasibility of a novel guidewire-based tangential sawing fragmentation (GTSF) technique to treat giant gastric bezoars. METHODS: This retrospective single-center study was performed in the Department of Gastroenterology and Hepatology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital. Ten patients with giant bezoars were consecutively enrolled from December 8, 2019 to April 8, 2021. We treated the 10 patients with the GTSF technique, recorded the GTSF procedure, and followed the patients with gastroscopy 2 weeks after the procedure. RESULTS: All patients were successfully treated by the GTSF technique, and the giant bezoar was broken into small pieces (<2 cm in diameter). The average operation time was 21.73 minutes, and the average fragmentation time was 8.06 minutes. Ten patients treated with the GTSF technique attained satisfactory treatment results, with no acute adverse events or alimentary canal injury during the procedure, and no bezoar residue remained as shown by gastroscopy 2 weeks after the procedure. CONCLUSIONS: The GTSF technique is a safe, effective, and feasible method for removing giant bezoars and can be considered as an alternative treatment of this disease.

Exploration of endoscopic findings and risk factors of early gastric cancer after eradication of Helicobacter pylori.

AIM: To explore the endoscopic features and risk factors of early gastric cancer (EGC) after eradication of Helicobacter pylori (H. pylori). METHODS: A total of 1961 patients who underwent esophago-gastro-duodenoscopy (EGD) with a history of successful H. pylori eradication were enrolled in this multicenter research. Among them, 162 EGC lesions of 132 patients were detected. The endoscopic features and risk factors of post-eradication EGC were explored. RESULTS: Severe atrophy (75.3% vs. 16.7%, p value <.01), intestinal metaplasia (96.3% vs. 77.1%, p value <.01), map-like redness (89.5% vs. 65.4%, p value <.01), distinct intermediate zone (IZ) (68.5% vs. 23.4%, p value <.01) and xanthoma (58.0% vs. 17.9%, p value <.01) were significantly more frequent in the CA group (patients with newly detected EGC after eradication of H. pylori) than in the NC group (patients without gastric cancer after eradication of H. pylori). In multivariate analysis, severe atrophy (odds ratio (OR) = 8.08; 95% confidence interval (CI), 3.43-20.0; p value<.01), map-like redness (OR = 1.75; 95% CI, 0.11-5.25; p value = .04), distinct IZ (OR = 2.87; 95% CI, 1.20-6.93; p value = .02) and xanthoma (OR = 2.84; 95% CI, 1.20-7.03; p value=.02) were proved to be risk factors for detection of EGC after eradication of H. pylori. CONCLUSIONS: Severe atrophy and map-like redness and distinct IZ and xanthoma are risk factors of EGC after eradication of H. pylori.

A deep learning-based system for identifying differentiation status and delineating the margins of early gastric cancer in magnifying narrow-band imaging endoscopy.

BACKGROUND : Accurate identification of the differentiation status and margins for early gastric cancer (EGC) is critical for determining the surgical strategy and achieving curative resection in EGC patients. The aim of this study was to develop a real-time system to accurately identify differentiation status and delineate the margins of EGC on magnifying narrow-band imaging (ME-NBI) endoscopy. METHODS : 2217 images from 145 EGC patients and 1870 images from 139 EGC patients were retrospectively collected to train and test the first convolutional neural network (CNN1) to identify EGC differentiation status. The performance of CNN1 was then compared with that of experts using 882 images from 58 EGC patients. Finally, 928 images from 132 EGC patients and 742 images from 87 EGC patients were used to train and test CNN2 to delineate the EGC margins. RESULTS : The system correctly predicted the differentiation status of EGCs with an accuracy of 83.3 % (95 % confidence interval [CI] 81.5 % - 84.9 %) in the testing dataset. In the man - machine contest, CNN1 performed significantly better than the five experts (86.2 %, 95 %CI 75.1 % - 92.8 % vs. 69.7 %, 95 %CI 64.1 % - 74.7 %). For delineating EGC margins, the system achieved an accuracy of 82.7 % (95 %CI 78.6 % - 86.1 %) in differentiated EGC and 88.1 % (95 %CI 84.2 % - 91.1 %) in undifferentiated EGC under an overlap ratio of 0.80. In unprocessed EGC videos, the system achieved real-time diagnosis of EGC differentiation status and EGC margin delineation in ME-NBI endoscopy. CONCLUSION : We developed a deep learning-based system to accurately identify differentiation status and delineate the margins of EGC in ME-NBI endoscopy. This system achieved superior performance when compared with experts and was successfully tested in real EGC videos.

A Brief Review of the Shape Memory Phenomena in Polymers and Their Typical Sensor Applications.

In this brief review, an introduction of the underlying mechanisms for the shape memory effect (SME) and various shape memory phenomena in polymers is presented first. After that, a summary of typical applications in sensors based on either heating or wetting activated shape recovery using largely commercial engineering polymers, which are programmed by means of in-plane pre-deformation (load applied in the length/width direction) or out-of-plane pre-deformation (load applied in the thickness direction), is presented. As demonstrated by a number of examples, many low-cost engineering polymers are well suited to, for instance, anti-counterfeit and over-heating/wetting monitoring applications via visual sensation and/or tactual sensation, and many existing technologies and products (e.g., holography, 3D printing, nano-imprinting, electro-spinning, lenticular lens, Fresnel lens, QR/bar code, Moiré pattern, FRID, structural coloring, etc.) can be integrated with the shape memory feature.

The effect of electrical stimulation on cortical cells in 3D nanofibrous scaffolds.

Cellular behaviors are significantly affected by cellular microenvironment, including mechanical supports, electrical and chemical cues, etc. Three dimensional conductive nanofibers (3D-CNFs) provide the capability to regulate cellular behaviors using mechanical, geometrical and electrical cues together, which are especially important in neural tissue engineering. However, very few studies were conducted to address combined effects of 3D nanofibrous scaffolds and electrical stimulation (ES) on cortical cell cultures. In the present study, polypyrrole (PPy)-coated electrospun polyacrylonitrile (PAN) nanofibers with a 3D structure were successfully prepared for the cortical cell culture, which was compared to cells cultured in the 2D-CNFs meshes, as well as that in the bare PAN nanofibers, both in 2D and 3D. While smooth PAN 3D nanofibers showed dispersive cell distribution, PPy coated 3D-CNFs showed clusters of cortical cells. The combined effects of 3D conductive nanofibers and ES on neurons and glial cells were studied. Different from previous observations on 2D substrates, pulsed electrical stimulations could prevent formation of cell clusters if applied at the beginning of culture, but could not disperse the clusters of cortical cells already formed. Furthermore, the electrical stimulations improved the proliferation of glial cells and accelerate neuron maturation. This study enriched the growing body of evidence for using electrical stimulation and 3D conductive nanofibers to control the culture of cortical cells, which have broad applications in neural engineering, such as implantation, biofunctional in vitro model, etc.

Fabrication and Characterization of Three-Dimensional (3D) Core-Shell Structure Nanofibers Designed for 3D Dynamic Cell Culture.

Three-dimensional elastic nanofibers (3D eNFs) can offer a suitable 3D dynamic microenvironment and sufficient flexibility to regulate cellular behavior and functional protein expression. In this study, we report a novel approach to prepare 3D nanofibers with excellent mechanical properties by solution-assisted electrospinning technology and in situ polymerization. The obtained 3D eNFs demonstrated excellent biocompatible properties to meet cell culture requirements under a dynamic environment in vitro. Moreover, these 3D eNFs also promoted human bone marrow mesenchymal stem cells (hMSCs) adhesion and collagen expression under biomechanical stimulation. The results demonstrated that this dynamic cell culture system could positively impact cellular collagen but has no significant effect on the proliferation of hMSCs grown in the 3D eNFs. This work may give rise to a new approach for constructing a 3D cell culture for tissue engineering.