Exosomal LINC00853 promotes progression of gastric cancer via the MAP17/PDZK1/AKT signaling pathway.

Although rare, there is ongoing research into biomarkers that predict the onset and recurrence of gastric cancer, particularly focusing on substances found in exosomes. Long non-coding RNAs (lncRNAs) have garnered attention for their potential in diagnosing gastric cancer. This study investigates the role of lncRNAs in gastric cancer, focusing on their presence in exosomes as potential biomarkers for the disease's onset and recurrence. We utilized the ArrayStar Human LncRNA array 2.0 to analyze lncRNA expression in tissues from early-stage gastric cancer patients. Our analysis highlighted LINC00853, which was significantly upregulated in cancer tissues and implicated in promoting epithelial-mesenchymal transition via the MAP17/PDZK1/AKT pathway. Functional studies on AGS and MKN74 gastric cancer cell lines demonstrated that LINC00853 facilitates cell proliferation, invasion, and migration. Additionally, RNA immunoprecipitation and electrophoretic mobility shift assays confirmed LINC00853 interaction with MAP17. Importantly, LINC00853 was also detected in exosomes from both patient samples and cell lines, and its downregulation led to decreased tumorigenicity in AGS cells. These findings suggest that both cellular and exosomal LINC00853 contribute to gastric cancer pathogenesis and may serve as valuable biomarkers for the disease.

Necking Reduction at Low Temperature in Aspect Ratio Etching of SiO2 at CF4/H2/Ar Plasma.

This study investigated the effect of temperature on the aspect-ratio etching of SiO2 in CF4/H2/Ar plasma using patterned samples of a 200 nm trench in a low-temperature reactive-ion etching system. Lower temperatures resulted in higher etch rates and aspect ratios for SiO2. However, the plasma property was constant with the chuck temperature, indicated by the line intensity ratio from optical emission spectroscopy monitoring of the plasma. The variables obtained from the characterization of the etched profile for the 200 nm trench after etching were analyzed as a function of temperature. A reduction in the necking ratio affected the etch rate and aspect ratio of SiO2. The etching mechanism of the aspect ratio etching of SiO2 was discussed based on the results of the surface composition at necking via energy-dispersive X-ray spectroscopy with temperature. The results suggested that the neutral species reaching the etch front of SiO2 had a low sticking coefficient. The bowing ratio decreased with lowering temperature, indicating the presence of directional ions during etching. Therefore, a lower temperature for the aspect ratio etching of SiO2 could achieve a faster etch rate and a higher aspect ratio of SiO2 via the reduction of necking than higher temperatures.

Impact of resident participation on surgical outcomes in laparoscopically assisted vaginal hysterectomy.

OBJECTIVE: To compare surgical outcomes in patients with benign diseases who underwent laparoscopically assisted vaginal hysterectomy (LAVH) to determine the association between surgical outcomes and resident participation in the gynecologic field. METHODS: A single-center retrospective study was conducted of patients diagnosed with benign gynecologic diseases who underwent LAVH between January 2010 and December 2015. Clinicopathologic characteristics and surgical outcomes were compared between the resident involvement and non-involvement groups. The primary endpoint was the 30-day postoperative morbidity. Observers were propensity matched for 17 covariates for resident involvement or non-involvement. RESULTS: Of the 683 patients involved in the study, 165 underwent LAVH with resident involvement and 518 underwent surgery without resident involvement. After propensity score matching (157 observations), 30-day postoperative morbidity occurred in 6 (3.8%) and 4 (2.5%) patients in the resident involvement and non-involvement groups, respectively (P = 0.501). The length of hospital stay differed significantly between the two groups: 5 days in the resident involvement group and 4 days in the non-involvement group (P < 0.001). On multivariate analysis, Charlson Comorbidity Index >2 (odds ratio [OR] 8.01, 95% confidence interval [CI] 2.68-23.96; P < 0.001), operative time (OR 1.02, 95% CI 1.01-1.03; P < 0.001), and estimated blood loss (OR 1.00, 95% CI 1.00-1.00; P < 0.001) were significantly associated with 30-day morbidity, but resident involvement was not statistically significant. CONCLUSION: There was no significant difference in the 30-day morbidity rate when residents participated in LAVH. These findings suggest that resident participation in LAVH may be a viable approach to ensure both residency education and patient safety.

A longitudinal molecular and cellular lung atlas of lethal SARS-CoV-2 infection in K18-hACE2 transgenic mice.

BACKGROUND: The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to approximately 500 million cases and 6 million deaths worldwide. Previous investigations into the pathophysiology of SARS-CoV-2 primarily focused on peripheral blood mononuclear cells from patients, lacking detailed mechanistic insights into the virus's impact on inflamed tissue. Existing animal models, such as hamster and ferret, do not faithfully replicate the severe SARS-CoV-2 infection seen in patients, underscoring the need for more relevant animal system-based research. METHODS: In this study, we employed single-cell RNA sequencing (scRNA-seq) with lung tissues from K18-hACE2 transgenic (TG) mice during SARS-CoV-2 infection. This approach allowed for a comprehensive examination of the molecular and cellular responses to the virus in lung tissue. FINDINGS: Upon SARS-CoV-2 infection, K18-hACE2 TG mice exhibited severe lung pathologies, including acute pneumonia, alveolar collapse, and immune cell infiltration. Through scRNA-seq, we identified 36 different types of cells dynamically orchestrating SARS-CoV-2-induced pathologies. Notably, SPP1+ macrophages in the myeloid compartment emerged as key drivers of severe lung inflammation and fibrosis in K18-hACE2 TG mice. Dynamic receptor-ligand interactions, involving various cell types such as immunological and bronchial cells, defined an enhanced TGFß signaling pathway linked to delayed tissue regeneration, severe lung injury, and fibrotic processes. INTERPRETATION: Our study provides a comprehensive understanding of SARS-CoV-2 pathogenesis in lung tissue, surpassing previous limitations in investigating inflamed tissues. The identified SPP1+ macrophages and the dysregulated TGFß signaling pathway offer potential targets for therapeutic intervention. Insights from this research may contribute to the development of innovative diagnostics and therapies for COVID-19. FUNDING: This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2020M3A9I2109027, 2021R1A2C2004501).

Evaluation of immunogenicity-induced DNA vaccines against different SARS-CoV-2 variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in 2019 and caused the coronavirus disease 2019 (COVID-19) pandemic worldwide. As of September 2023, the number of confirmed coronavirus cases has reached over 770 million and caused nearly 7 million deaths. The World Health Organization assigned and informed the characterization of variants of concern (VOCs) to help control the COVID-19 pandemic through global monitoring of circulating viruses. Although many vaccines have been proposed, developing an effective vaccine against variants is still essential to reach the endemic stage of COVID-19. We designed five DNA vaccine candidates composed of the first isolated genotype and major SARS-CoV-2 strains from isolated Korean patients classified as VOCs, such as Alpha, Beta, Gamma, and Delta. To evaluate the immunogenicity of each genotype via homologous and heterologous vaccination, mice were immunized twice within a 3-week interval, and the blood and spleen were collected 1 week after the final vaccination to analyze the immune responses. The group vaccinated with DNA vaccine candidates based on the S genotype and the Alpha and Beta variants elicited both humoral and cellular immune responses, with higher total IgG levels and neutralizing antibody responses than the other groups. In particular, the vaccine candidate based on the Alpha variant induced a highly diverse cytokine response. Additionally, we found that the group subjected to homologous vaccination with the S genotype and heterologous vaccination with S/Alpha induced high total IgG levels and a neutralization antibody response. Homologous vaccination with the S genotype and heterologous vaccination with S/Alpha and S/Beta significantly induced IFN-γ immune responses. The immunogenicity after homologous vaccination with S and Alpha and heterologous vaccination with the S/Alpha candidate was better than that of the other groups, indicating the potential for developing novel DNA vaccines against different SARS-CoV-2 variants.

No Interference of H9 Extract on Trastuzumab Pharmacokinetics in Their Combinations.

Trastuzumab is used to treat breast cancer patients overexpressing human epidermal growth factor receptor 2, but resistance and toxicity limit its uses, leading to attention to trastuzumab combinations. Recently, the synergistic effect of trastuzumab and H9 extract (H9) combination against breast cancer has been reported. Because drug exposure determines its efficacy and toxicity, the question of whether H9 changes trastuzumab exposure in the body has been raised. Therefore, this study aimed to characterize trastuzumab pharmacokinetics and elucidate the effect of H9 on trastuzumab pharmacokinetics at a combination dose that shows synergism in mice. As a result, trastuzumab showed linear pharmacokinetics after its intravenous administration from 1 to 10 mg/kg. In the combination of trastuzumab and H9, single and 2-week treatments of oral H9 (500 mg/kg) did not influence trastuzumab pharmacokinetics. In the multiple-combination treatments of trastuzumab and H9 showing their synergistic effect (3 weeks of trastuzumab with 2 weeks of H9), the pharmacokinetic profile of trastuzumab was comparable to that of 3 weeks of trastuzumab alone. In tissue distribution, the tissue to plasma ratios of trastuzumab below 1.0 indicated its limited distributions within the tissues, and these patterns were unaffected by H9. These results suggest that the systemic and local exposures of trastuzumab are unchanged by single and multiple-combination treatments of H9.

SARS-CoV-2 infection engenders heterogeneous ribonucleoprotein interactions to impede translation elongation in the lungs.

Translational regulation in tissue environments during in vivo viral pathogenesis has rarely been studied due to the lack of translatomes from virus-infected tissues, although a series of translatome studies using in vitro cultured cells with viral infection have been reported. In this study, we exploited tissue-optimized ribosome profiling (Ribo-seq) and severe-COVID-19 model mice to establish the first temporal translation profiles of virus and host genes in the lungs during SARS-CoV-2 pathogenesis. Our datasets revealed not only previously unknown targets of translation regulation in infected tissues but also hitherto unreported molecular signatures that contribute to tissue pathology after SARS-CoV-2 infection. Specifically, we observed gradual increases in pseudoribosomal ribonucleoprotein (RNP) interactions that partially overlapped the trails of ribosomes, being likely involved in impeding translation elongation. Contemporaneously developed ribosome heterogeneity with predominantly dysregulated 5 S rRNP association supported the malfunction of elongating ribosomes. Analyses of canonical Ribo-seq reads (ribosome footprints) highlighted two obstructive characteristics to host gene expression: ribosome stalling on codons within transmembrane domain-coding regions and compromised translation of immunity- and metabolism-related genes with upregulated transcription. Our findings collectively demonstrate that the abrogation of translation integrity may be one of the most critical factors contributing to pathogenesis after SARS-CoV-2 infection of tissues.

Chondrodysplasia-inducing COL2A1 p.Gly1170Ser causes an ER storage defect without associated unfolded protein response in a human cartilage model.

Collagenopathies are a group of clinically diverse disorders caused by defects in collagen folding and secretion. For example, mutations in the gene encoding collagen type-II ( COL2A1 ), the primary collagen in cartilage, can lead to chondrodysplasias of various severities. One example is the Gly1170Ser substitution in procollagen-II, which causes precocious osteoarthritis and Legg-Calvé-Perthes disease. Here, we develop and characterize a novel induced pluripotent stem cell-based cartilage model of this disease, including both hetero- and homozygous genotypes. Biochemical characterization reveals that Gly1170Ser procollagen-II is notably slow to fold and secrete. Procollagen-II accumulates intracellularly, consistent with an endoplasmic reticulum (ER) storage disorder. Intriguingly, perhaps due to the pathologic substitution occurring within a triple-helical domain that lacks hydrophobic character, this ER protein accumulation is not recognized by cellular stress responses, such as the unfolded protein response. Interactome studies show that Gly1170Ser procollagen-II interacts to a greater extent with certain ER chaperones and modifying enzymes than wild-type, consistent with its slow folding. These findings provide mechanistic elucidation into the etiology of this disease. Moreover, the cartilage model developed here provides a valuable platform to rapidly screen and develop therapeutic strategies that can restore procollagen folding and secretion in this collagenopathy and others.

Adipose Tissue-Derived Mesenchymal Stem Cells Extend the Lifespan and Enhance Liver Function in Hepatocyte Organoids.

In this study, we generated hepatocyte organoids (HOs) using frozen-thawed primary hepatocytes (PHs) within a three-dimensional (3D) Matrigel dome culture in a porcine model. Previously studied hepatocyte organoid analogs, spheroids, or hepatocyte aggregates created using PHs in 3D culture systems have limitations in their in vitro lifespans. By co-culturing adipose tissue-derived mesenchymal stem cells (A-MSCs) with HOs within a 3D Matrigel dome culture, we achieved a 3.5-fold increase in the in vitro lifespan and enhanced liver function compared to a conventional two-dimensional (2D) monolayer culture, i.e., more than twice that of the HO group cultured alone, reaching up to 126 d. Although PHs were used to generate HOs, we identified markers associated with cholangiocyte organoids such as cytokeratin 19 and epithelial cellular adhesion molecule (EPCAM). Co-culturing A-MSCs with HOs increased the secretion of albumin and urea and glucose consumption compared to HOs cultured alone. After more than 100 d, we observed the upregulation of tumor protein P53 (TP53)-P21 and downregulation of EPCAM, albumin (ALB), and cytochrome P450 family 3 subfamily A member 29 (CYP3A29). Therefore, HOs with function and longevity improved through co-culturing with A-MSCs can be used to create large-scale human hepatotoxicity testing models and precise livestock nutrition assessment tools.

Improved Pharmacokinetic Feasibilities of Mirabegron-1,2-Ethanedisulfonic Acid, Mirabegron-1,5-Naphthalenedisulfonic Acid, and Mirabegron-L-Pyroglutamic Acid as Co-Amorphous Dispersions in Rats and Mice.

Mirabegron (MBR) is a ß3-adrenoceptor agonist used for treating overactive bladder syndrome. Due to its poor solubility and low bioavailability (F), the development of novel MBR formulations has garnered increasing attention. Recently, co-amorphous dispersions of MBR, such as MBR-1,2-ethanedisulfonic acid (MBR-EFA), MBR-1,5-naphthalenedisulfonic acid (MBR-NDA), and MBR-L-pyroglutamic acid (MBR-PG), have been developed, showing improved solubility and thermodynamic stability. Nevertheless, the pharmacokinetic feasibility of these co-amorphous dispersions has not been evaluated. Therefore, this study aimed to characterize the pharmacokinetic profiles of MBR-EFA, MBR-NDA, and MBR-PG in rats and mice. Our results exhibited that relative F24h and AUC0-24h values of MBR in MBR-EFA, MBR-NDA, and MBR-PG rats were increased by 143-195% compared with the MBR rats. The absolute F24h, relative F24h, and AUC0-24h values of MBR in MBR-EFA and MBR-NDA mice were enhanced by 178-234% compared with the MBR mice. In tissue distribution, MBR was extensively distributed in the gastrointestinal tract, liver, kidneys, lung, and heart of mice. Notably, MBR distribution in the liver, kidneys, and lung was considerably high in MBR-EFA, MBR-NDA, or MBR-PG mice compared with MBR mice. These findings highlight the potential of these co-amorphous dispersions to enhance oral F of MBR.

Gemcitabine and rapamycin-loaded mixed polymeric thermogel for metastatic pancreatic cancer therapy.

Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer-related death and has a poor 5-year overall survival. The superior therapeutic benefits of combination or co-administration of drugs as intraperitoneal chemotherapy have increased interest in developing strategies to deliver chemotherapeutic agents to patients safely. In this study, we prepared a gel comprising the thermosensitive poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) polymer and gemcitabine (GEM), which is currently used as the primary chemotherapy for PDAC and rapamycin (RAPA), a mammalian TOR (mTOR) inhibitor, to deliver the drug through intraperitoneal injection. We performed in vitro cytotoxicity experiments to verify the synergistic effects of the two drugs at different molar ratios and characterized the physicochemical properties of the GEM, RAPA, and GEM/RAPA-loaded thermosensitive PLGA-PEG-PLGA gels, hereafter referred to as (g(G), g(R), and g(GR)), respectively. The g(GR) comprising PLGA-PEG-PLGA polymer (25% w/v) and GEM and RAPA at a molar ratio of 11:1 showed synergism and was optimized. An in vitro cytotoxicity assay was performed by treating Panc-1-luc2 tumor spheroids with g(G), g(R), or g(GR). The g(GR) treatment group showed a 2.75-fold higher inhibition rate than the non-treated (NT) and vehicle-treated groups. Furthermore, in vivo drug release assay in mice by intraperitoneal injection of g(G), g(R), or g(GR) showed a more rapid release rate of GEM than RAPA, similar to the in vitro release pattern. The drugs in the gel were released faster in vivo than in vitro and degraded in 48 h. In addition, g(GR) showed the highest anti-tumor efficacy with no toxicity to mice. These results provide evidence for the safety and efficacy of g(GR) for intraperitoneal drug delivery. This study will assist in developing and clinically administering topical anti-cancer formulations.

Hemispherically asymmetric Hadley cell response to CO2 removal.

A poleward shift of the Hadley cell (HC) edge in a warming climate, which contributes to the expansion of drought-prone subtropical regions, has been widely documented. The question addressed here is whether this shift is reversible with CO2 removal. By conducting large-ensemble experiments where CO2 concentrations are systematically increased and then decreased to the present-day level, we show that the poleward-shifted HC edge in a warming climate does not return to its present-day state when CO2 concentrations are reduced. While the Southern Hemisphere HC edge remains poleward of its present-day state, the Northern Hemisphere HC edge ends up farther equatorward of its present-day state. Such hemispherically asymmetric HC edge changes are closely associated with the changes in vertical wind shear in the subtropical atmosphere, which result from the long adjustment time of the ocean response to CO2 removal. Our findings suggest that CO2 removal may not guarantee the recovery of the subtropical dryness associated with the HC changes.

Photobiomodulation therapy activates YAP and triggers proliferation and dedifferentiation of Müller glia in mammalian retina.

Photobiomodulation therapy has been proposed as a promising therapeutic approach for retinal degenerative diseases. However, its effect on the regenerative capacity in mammalian retina and its intracellular signalling mechanisms remain unknown. Here, we show that photobiomodulation with 670 nm light stimulates Müller glia cell cycle re-entry and dedifferentiation into a progenitor-like state in both the uninjured and injured retina. We also find that 670 nm light treatment inhibits the Hippo pathway, which is activated in Müller glia following NaIO3-induced retinal injury. YAP, a major downstream effector of the Hippo signalling pathway was translocated into the nucleus of Müller glia along with YAP dephosphorylation in retina treated with 670 nm light. Deficiency of YAP attenuated Müller glia cell cycle re-entry and dedifferentiation. Our data reveal that the Hippo-YAP signalling pathway is associated with the photostimulatory effect on regenerative response in mammalian retina, and suggest a potential therapeutic strategy for retinal degenerative diseases. [BMB Reports 2023; 56(9): 502-507].

Acoustic and Magnetic Stimuli-Based Three-Dimensional Cell Culture Platform for Tissue Engineering.

In a conventional two-dimensional (2D) culture method, cells are attached to the bottom of the culture dish and grow into a monolayer. These 2D culture methods are easy to handle, cost-effective, reproducible, and adaptable to growing many different types of cells. However, monolayer 2D cell culture conditions are far from those of natural tissue, indicating the need for a three-dimensional (3D) culture system. Various methods, such as hanging drop, scaffolds, hydrogels, microfluid systems, and bioreactor systems, have been utilized for 3D cell culture. Recently, external physical stimulation-based 3D cell culture platforms, such as acoustic and magnetic forces, were introduced. Acoustic waves can establish acoustic radiation force, which can induce suspended objects to gather in the pressure node region and aggregate to form clusters. Magnetic targeting consists of two components, a magnetically responsive carrier and a magnetic field gradient source. In a magnetic-based 3D cell culture platform, cells are aggregated by changing the magnetic force. Magnetic fields can manipulate cells through two different methods: positive magnetophoresis and negative magnetophoresis. Positive magnetophoresis is a way of imparting magnetic properties to cells by labeling them with magnetic nanoparticles. Negative magnetophoresis is a label-free principle-based method. 3D cell structures, such as spheroids, 3D network structures, and cell sheets, have been successfully fabricated using this acoustic and magnetic stimuli-based 3D cell culture platform. Additionally, fabricated 3D cell structures showed enhanced cell behavior, such as differentiation potential and tissue regeneration. Therefore, physical stimuli-based 3D cell culture platforms could be promising tools for tissue engineering.

Synergistic Encapsulation of Paclitaxel and Sorafenib by Methoxy Poly(Ethylene Glycol)-b-Poly(Caprolactone) Polymeric Micelles for Ovarian Cancer Therapy.

Ovarian cancer has a high mortality rate due to difficult detection at an early stage. It is necessary to develop a novel anticancer treatment that demonstrates improved efficacy while reducing toxicity. Here, using the freeze-drying method, micelles encapsulating paclitaxel (PTX) and sorafenib (SRF) with various polymers were prepared, and the optimal polymer (mPEG-b-PCL) was selected by measuring drug loading (%), encapsulation efficiency (%), particle size, polydispersity index, and zeta potential. The final formulation was selected based on a molar ratio (PTX:SRF = 1:2.3) with synergistic effects on two ovarian cancer cell lines (SKOV3-red-fluc, HeyA8). In the in vitro release assay, PTX/SRF micelles showed a slower release than PTX and SRF single micelles. In pharmacokinetic evaluation, PTX/SRF micelles showed improved bioavailability compared to PTX/SRF solution. In in vivo toxicity assays, no significant differences were observed in body weight between the micellar formulation and the control group. The anticancer effect of PTX/SRF combination therapy was improved compared to the use of a single drug. In the xenografted BALB/c mouse model, the tumor growth inhibition rate of PTX/SRF micelles was 90.44%. Accordingly, PTX/SRF micelles showed improved anticancer effects compared to single-drug therapy in ovarian cancer (SKOV3-red-fluc).

Change of metformin concentrations in the liver as a pharmacological target site of metformin after long-term combined treatment with ginseng berry extract.

Metformin as an oral glucose-lowering drug is used to treat type 2 diabetic mellitus. Considering the relatively high incidence of cardiovascular complications and other metabolic diseases in diabetic mellitus patients, a combination of metformin plus herbal supplements is a preferrable way to improve the therapeutic outcomes of metformin. Ginseng berry, the fruit of Panax ginseng Meyer, has investigated as a candidate in metformin combination mainly due to its anti-hyperglycemic, anti-hyperlipidemic, anti-obesity, anti-hepatic steatosis and anti-inflammatory effects. Moreover, the pharmacokinetic interaction of metformin via OCTs and MATEs leads to changes in the efficacy and/or toxicity of metformin. Thus, we assessed how ginseng berry extract (GB) affects metformin pharmacokinetics in mice, specially focusing on the effect of the treatment period (i.e., 1-day and 28-day) of GB on metformin pharmacokinetics. In 1-day and 28-day co-treatment of metformin and GB, GB did not affect renal excretion as a main elimination route of metformin and GB therefore did not change the systemic exposure of metformin. Interestingly, 28-day co-treatment of GB increased metformin concentration in the livers (i.e., 37.3, 59.3% and 60.9% increases versus 1-day metformin, 1-day metformin plus GB and 28-day metformin groups, respectively). This was probably due to the increased metformin uptake via OCT1 and decreased metformin biliary excretion via MATE1 in the livers. These results suggest that co-treatment of GB for 28 days (i.e., long-term combined treatment of GB) enhanced metformin concentration in the liver as a pharmacological target tissue of metformin. However, GB showed a negligible impact on the systemic exposure of metformin in relation to its toxicity (i.e., renal and plasma concentrations of metformin).

Recombinant measles virus encoding the spike protein of SARS-CoV-2 efficiently induces Th1 responses and neutralizing antibodies that block SARS-CoV-2 variants.

Owing to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants, the development of effective and safe vaccines has become a priority. The measles virus (MeV) vaccine is an attractive vaccine platform as it has been administered to children for more than 40 years in over 100 countries. In this study, we developed a recombinant MeV expressing the full-length SARS-CoV-2 spike protein (rMeV-S) and tested its efficacy using mouse and hamster models. In hCD46Tg mice, two-dose rMeV-S vaccination induced higher Th1 secretion and humoral responses than one-dose vaccination. Interestingly, neutralizing antibodies induced by one-dose and two-dose rMeV-S immunization effectively blocked the entry of the α, ß, γ, and δ variants of SARS-CoV-2. Furthermore, two-dose rMeV-S immunization provided complete protection against SARS-CoV-2 in the hamster model. These results suggest the potential of rMeV-S as a vaccine candidate for targeting SARS-CoV-2 and its variants.

Modularized dynamic cell culture platform for efficient production of extracellular vesicles and sequential analysis.

Extracellular vesicles (EVs) are nanometer-sized particles naturally secreted by cells for intercellular communication that encapsulate bioactive cargo, such as proteins and RNA, with a lipid bilayer. Tumor cell-derived EVs (tdEVs) are particularly promising biomarkers for cancer research because their contents reflect the cell of origin. In most studies, tdEVs have been obtained from cancer cells cultured under static conditions, thus lacking the ability to recapitulate the microenvironment of cells in vivo. Recent developments in perfusable cell culture systems have allowed oxygen and a nutrient gradient to mimic the physiological and cellular microenvironment. However, as these systems are perfused by circulating the culture medium within the unified structure, independently harvesting cells and EVs at each time point for analysis presents a limitation. In this study, a modularized cell culture system is designed for the perfusion and real-time collection of EVs. The system consists of three detachable chambers, one each for fresh medium, cell culture, and EV collection. The fresh medium flows from the medium chamber to the culture chamber at a flow rate controlled by the hydraulic pressure injected with a syringe pump. When the culture medium containing EVs exceeds a certain volume within the chamber, it overflows into the collection chamber to harvest EVs. The compact and modularized chambers are highly interoperable with conventional cell culture modalities used in the laboratory, thus enabling various EV-based assays.