Enhanced quality of hESC-derived melanocytes through modified concentration of endothelin-1.

The study investigated the effectiveness of EDN1 and EDN3 cytokines in the differentiation of melanocytes from hESCs. The findings showed that 100 nM EDN1 was more effective in promoting hESC to CD117+/TYR+ melanoblasts compared to 100 nM EDN3. Additionally, maintaining melanoblasts is beneficial for preserving the ability to proliferate. The study found that 10 nM EDN1 helped maintain the proliferation of melanoblasts without over maturing them into melanocytes in the late stage of differentiation. Thus, using 100 nM EDN1 in the initial stage and 10 nM EDN1 in the late stage proved to be an efficient and cost-effective method for obtaining hESC-derived melanocytes. The preliminary results suggest that EDN1 promotes melanoblast formation during the initial differentiation stage through its binding to both the EDNRB receptor and EDNRA receptor. This study provides a valuable tool for studying the development of human melanocytes and modelling the biology of disease.

Seed-borne bacterial synthetic community resists seed pathogenic fungi and promotes plant growth.

AIMS: In this study, the control effects of synthetic microbial communities composed of peanut seed bacteria against seed aflatoxin contamination caused by Aspergillus flavus and root rot by Fusarium oxysporum were evaluated. METHODS AND RESULTS: Potentially conserved microbial synthetic communities (C), growth-promoting synthetic communities (S), and combined synthetic communities (CS) of peanut seeds were constructed after 16S rRNA Illumina sequencing, strain isolation, and measurement of plant growth promotion indicators. Three synthetic communities showed resistance to root rot and CS had the best effect after inoculating into peanut seedlings. This was achieved by increased defense enzyme activity and activated salicylic acid (SA)-related, systematically induced resistance in peanuts. In addition, CS also inhibited the reproduction of A. flavus on peanut seeds and the production of aflatoxin. These effects are related to bacterial degradation of toxins and destruction of mycelia. CONCLUSIONS: Inoculation with a synthetic community composed of seed bacteria can help host peanuts resist the invasion of seeds by A. flavus and seedlings by F. oxysporum and promote the growth of peanut seedlings.

Immunological function of Bombyx Toll9-2 in the silkworm (Bombyx mori) larval midgut: Activation by Escherichia coli/lipopolysaccharide and regulation of growth.

Toll receptors are important regulators of insects' innate immune system which, upon binding of pathogen molecules, activate a conserved signal transduction cascade known as the Toll pathway. RNA interference (RNAi) is a powerful tool to study the function of genes via reverse genetics. However, due to the reported refractory of RNAi efficiency in lepidopteran insects, successful reports of silencing of Toll receptors in the silkworm Bombyx mori have not been reported yet. In this study, a Toll receptor of the silkworm Bombyx Toll9-2 (BmToll9-2) was cloned and its expression and function were analyzed. The results showed that BmToll9-2 contains an ectodomain (ECD) with a signal peptide and nine leucine-rich repeats, a transmembrane helix, and a cytoplasmic region with a Toll/interleukin-1 domain. Phylogenetic analysis indicates that BmToll9-2 clusters with other insect Toll9 receptors and mammalian Toll-like receptor 4. Oral infection of exogenous pathogens showed that the Gram-negative bacterium Escherichia coli and its main cell wall component lipopolysaccharide (LPS), as well as the Gram-positive bacterium Staphylococcus aureus and its main cell wall component peptidoglycan, significantly induce BmToll9-2 expression in vivo. LPS also induced the expression of BmToll9-2 in BmN4 cells in vitro. These observations indicate its role as a sensor in the innate immunity to exogenous pathogens and as a pathogen-associated receptor that is responsive to LPS. RNAi of BmToll9-2 was effective in the midgut and epidermis. RNAi-mediated knock-down of BmToll9-2 reduced the weight and growth of the silkworm. Bacterial challenge following RNAi upregulated the expression of BmToll9-2 and rescued the weight differences of the silkworm, which may be related to its participation in the immune response and the regulation of the microbiota in the midgut lumen of the silkworm larvae.

Knowledge, attitude and practice toward to artificial intelligent patient-controlled analgesia among anesthesiologists: a cross-sectional study in east China's Jiangsu Province.

BACKGROUND: Inadequate postoperative analgesia greatly affects the recovery of patients, can poses a substantial health and economic burden. Patient-controlled analgesia is the most commonly used method for postoperative pain relief. However, the situation of inadequate analgesia still exists. Artificial intelligent Patient-controlled analgesia (Ai-PCA) system can make it easier for medical staff to understand the pain level of patients in order to deal with it in time. So far, several studies have investigated anesthesiologists' knowledge and management of Ai-PCA. OBJECTIVE: This study aimed to assess the degree of anesthesiologists' knowledge, attitude and their practice (KAP) towards Ai-PCA in east China's Jiangsu Province. METHODS: This cross-sectional study was conducted among 396 anesthesiologists working in tertiary hospitals. The data were collected using a pretested, structured and self-administered KAP questionnaire. The data were analyzed using Independent t-test, analysis of variance, Pearson's correlation and multiple linear regression tests. RESULTS: Five hundred twelve questionnaires were collected, 396 anesthesiologists (190 Male, and 206 Female) were included in our study for statistical analysis. The score of knowledge, attitude, practice was 5.49 ((SD = 1.65; range:0-8), 37.45 (SD = 4.46; range:9-45), and 26.41 (SD = 9.61; range:9-45), respectively. Among the participants, 309 (78%) and 264 (66.7%) had good knowledge and positive attitudes toward Ai-PCA, respectively. However, only 81 (20.5%) of the participants exhibited good practice regarding Ai-PCA. Participation in Ai-PCA training showed a significant correlation with knowledge, attitude and practice scores. Besides, age, years of experience and professional titles of anesthesiologists were correlated with knowledge scores. The title of the anesthesiologist was associated with attitude scores. And the marital status of anesthesiologists was correlated with practice scores. CONCLUSION: Our findings revealed the score of practice regarding Ai-PCA are very poor among anesthesiologists in east China's Jiangsu Province. The utilization of Ai-PCA was found to be impacted by whether the individual had received training. This calls for a comprehensive approach should be conducted for raising the level of knowledge, attitude, and practice of anesthesiologist on using Ai-PCA and more Ai-PCA training to be included in the daily learning. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( www.chictr.org.cn ; 27/10/2023; ChiCTR2300077070).

Thrombin-targeted screening of anticoagulant active components from Polygonum amplexicaule D. Don var. sinense Forb by affinity ultrafiltration coupled with UPLC-Q-TOF-MS.

INTRODUCTION: Polygonum amplexicaule D. Don var. sinense Forb (PAF), a medicinal plant, has the effect of promoting blood circulation and removing blood stasis. However, the active compounds and targets of its anticoagulant effect are still unclear. OBJECTIVES: This study aims to establish an effective reversely thrombin-targeted screening method for anticoagulant active components in PAF by affinity ultrafiltration (AUF) coupled with ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectroscopy (UPLC-Q-TOF-MS). METHODS: Different polar parts of PAF were screened for potential thrombin ligands by AUF-HPLC and identified by UPLC-Q-TOF-MS. After studying the affinity between ligands and thrombin by molecular docking, the antithrombotic activity of ligands was detected in vivo by zebrafish thrombus model, and in vitro by chromogenic substrate method. The mechanism of such ligands on thrombin was further studied by coagulation factor assay. RESULTS: Eleven potential thrombin ligands from PAF were screened by the AUF-UPLC-Q-TOF-MS method, and two compounds (butyl gallate and ß-sitosterol) with significant anticoagulant activity were discovered via in vitro and in vivo activity testing. CONCLUSION: A method system based on AUF-UPLC-Q-TOF-MS, molecular docking and in vivo and in vitro experiments also provided a powerful tool for further exploration of anticoagulant active components in PAF.

Screening of anti-thrombin active components from Ligusticum chuanxiong by affinity-ultrafiltration coupled with HPLC-Q-Orbitrap-MSn.

INTRODUCTION: Ligusticum chuanxiong ('chuanxiong') is a traditional Chinese medicine for promoting blood circulation and removing blood stasis, which is often used to treat thrombotic diseases. However, its potential anticoagulant active ingredients have been unexplored. OBJECTIVES: The study aims to establish an affinity ultrafiltration mass spectrometry (AUF-MS) method for rapid screening of anti-thrombin active components of chuanxiong and to verify it in vitro. METHOD: In this study, the chemical constituents of different parts of chuanxiong were determined. A method for rapid screening of anticoagulant active ingredients by AUF-MS was established using thrombin as an affinity receptor target. Subsequently, the anticoagulant effect of such ligands was verified by in vitro anticoagulation experiments such as chromogenic substrate method and in vitro coagulation assay. Then the possible interaction mechanism between these ligands and thrombin was further studied by molecular docking. RESULTS: Twenty-one components were detected from different parts of chuanxiong. And three potential anti-thrombin active components were screened: ferulic acid, chlorogenic acid, isochlorogenic acid A by AUF coupled with high-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (HPLC-Q-Orbitrap-MSn ). The in vitro activity experiments and molecular docking revealed that these potential ligands exhibited strong binding ability and inhibitory activities on thrombin. CONCLUSION: The present study revealed that chuanxiong is a traditional Chinese medicine with excellent anticoagulation effects. Meanwhile, the integrated strategy based on AUF-MS, in vitro experiments and molecular docking also provided a powerful tool for further exploration of active ingredients responsible for the anticoagulant activity in chuanxiong.

Influence of Different Pt Functionalization Modes on the Properties of CuO Gas-Sensing Materials.

The functionalization of noble metals is an effective approach to lowering the sensing temperature and improving the sensitivity of metal oxide semiconductor (MOS)-based gas sensors. However, there is a dearth of comparative analyses regarding the differences in sensitization mechanisms between the two functionalization modes of noble metal loading and doping. In this investigation, we synthesized Pt-doped CuO gas-sensing materials using a one-pot hydrothermal method. And for Pt-loaded CuO, Pt was deposited on the synthesized pristine CuO surface by using a dipping method. We found that both functionalization methods can considerably enhance the response and selectivity of CuO toward NO2 at low temperatures. However, we observed that CuO with Pt loading had superior sensing performance at 25 °C, while CuO with Pt doping showed more substantial response changes with an increase in the operating temperature. This is mainly due to the different dominant roles of electron sensitization and chemical sensitization resulting from the different forms of Pt present in different functionalization modes. For Pt doping, electron sensitization is stronger, and for Pt loading, chemical sensitization is stronger. The results of this study present innovative ideas for understanding the optimization of noble metal functionalization for the gas-sensing performance of metal oxide semiconductors.

A HiPAD Integrated with rGO/MWCNTs Nano-Circuit Heater for Visual Point-of-Care Testing of SARS-CoV-2.

Nowadays, the main obstacle for further miniaturization and integration of nucleic acids point-of-care testing devices is the lack of low-cost and high-performance heating materials for supporting reliable nucleic acids amplification. Herein, reduced graphene oxide hybridized multi-walled carbon nanotubes nano-circuit integrated into an ingenious paper-based heater is developed, which is integrated into a paper-based analytical device (named HiPAD). The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still raging across the world. As a proof of concept, the HiPAD is utilized to visually detect the SARS-CoV-2 N gene using colored loop-mediated isothermal amplification reaction. This HiPAD costing a few dollars has comparable detection performance to traditional nucleic acids amplifier costing thousands of dollars. The detection range is from 25 to 2.5 × 1010 copies mL-1 in 45 min. The detection limit of 25 copies mL-1 is 40 times more sensitive than 1000 copies mL-1 in conventional real-time PCR instruments. The disposable paper-based chip could also avoid potential secondary transmission of COVID-19 by convenient incineration to guarantee biosafety. The HiPAD or easily expanded M-HiPAD (for multiplex detection) has great potential for pathogen diagnostics in resource-limited settings.

AI triage or manual triage? Exploring medical staffs' preference for AI triage in China.

OBJECTIVES: The introduction of AI technology in healthcare presents both opportunities and challenges. The aim of this study was to investigate medical staffs' preference for AI triage and the influencing factors. METHODS: A survey was conducted online among medical staffs in China from March 4th to April 28th, 2021. Participants were recruited through multiple channels, including medical professional platforms and social media. A total of 677 valid responses were obtained from medical staff members located in 28 provinces across China. RESULTS: The results showed that AI triage had an overall acceptance rate of 77.1%, and 45.2% of the medical staffs surveyed preferred "AI triage exclusively." Direct experience was positively associated with medical staffs' preference for AI triage (ß = 0.223, p < .001). Additionally, greater exposure to a variety of media was positively associated with the perceived value of AI technology, which, in turn, increased preference for AI triage (ß = 0.040, SE = 0.013, p < .001, 95% CI = [0.017, 0.067]). CONCLUSION: Medical staffs generally hold a favorable attitude towards AI triage, particularly in areas with a high medical burden and during pandemics. In a multimedia environment, media exposure variety impacts medical staffs' preferences through their perceived value of AI technology. This study has implications for the implementation of AI triage on a larger scale.

Knowledge, Attitudes and Practices Among Anesthesia and Thoracic Surgery Medical Staff Toward Ai-PCA.

Purpose: Artificial intelligence (AI) is increasingly influencing various medical fields, including anesthesiology. The Introduction of artificial intelligent patient-controlled analgesia (Ai-PCA) has been seen as a significant advancement in pain management. However, the adoption and practical application of Ai-PCA by medical staff, particularly in anesthesia and thoracic surgery, have not been extensively studied. This study aimed to investigate the knowledge, attitudes and practices (KAP) among anesthesia and thoracic surgery medical staff toward artificial intelligent patient-controlled analgesia (Ai-PCA). Participants and Methods: This web-based cross-sectional study was conducted between November 1, 2023 and November 15, 2023 at Jiangsu Cancer Hospital. A self-designed questionnaire was developed to collect demographic information of anesthesia and thoracic surgery medical staff, and to assess their knowledge, attitudes and practices toward Ai-PCA. Results: A total of 519 valid questionnaires were collected. Among the participants, 278 (53.56%) were female, 497 (95.76%) were employed in the field of anesthesiology, and 188 (36.22%) had participated in Ai-PCA training. The mean knowledge, attitude, and practice scores were 7.8±1.75 (possible range: 0-10), 37.43±4.16 (possible range: 9-45), and 28.38±9.27 (possible range: 9-45), respectively. Conclusion: The findings revealed that anesthesia and thoracic surgery medical staff have sufficient knowledge, active attitudes, but poor practices toward the Ai-PCA. Comprehensive training programs are needed to improve anesthesia and thoracic surgery medical staff's practices in this area.

Association between Weight-Adjusted Waist Index and depressive symptoms: A nationally representative cross-sectional study from NHANES 2005 to 2018.

BACKGROUND: Depressive symptoms are strongly associated with the development of various diseases and are one of the leading causes of disability in the world. However, the relationship between weight-adjusted waist index (WWI) and depressive symptoms has not been studied. This study aimed to assess the relationship between depressive symptoms and WWI. METHODS: This study took NHANES data from 2005 to 2018 with 32,374 participants. Depressive symptoms were measured by a questionnaire (PHQ-9).WWI was determined by dividing the square root of waist circumference (cm) by weight (kg). Multivariate logistic regression models, smoothed curve fitting, and weighted generalized additive model (GAM) regression were used to examine the relationship between depressive symptoms and WWI, BMI, and waist circumference. Subgroup analyses and interaction tests were also performed. RESULTS: In fully adjusted models, the OR (95 % CI) for WWI and depressive symptoms with WWI, BMI, and waist circumference were 1.18 (1.05, 1.34), BMI 1.01 (1.00, 1.02, 1.01 (1.00, 1.01), respectively. Participants in the highest quartile (Q4) had a 49 % higher depressive symptoms compared to those in the lowest quartile (Q1) (OR = 1.49, 95 % CI:1.14-1.96). Subgroup analyses and interaction tests showed a stable relationship between depressive symptoms and WWI. LIMITATIONS: It is difficult to determine a causal relationship between the two; questionnaire collection may be somewhat biased; CONCLUSIONS: WWI was positively associated with depressive symptoms. This association was stronger than BMI and waist circumference. However, this relationship was stable. This study emphasizes the potential utility of WWI in preventing depressive symptoms and improving prognosis in the population.

A self-assembled graphene oxide adjuvant induces both enhanced humoral and cellular immune responses in influenza vaccine.

Antiviral vaccine is essential for preventing and controlling virus spreading, along with declining morbidity and mortality. A major challenge in effective vaccination lies in the ability to enhance both the humoral and cellular immune responses by adjuvants. Herein, self-assembled nanoparticles based on graphene oxide quantum dots with components of carnosine, resiquimod and Zn2+ ions, namely ZnGC-R, are designed as a new adjuvant for influenza vaccine. With its high capability for antigen-loading, ZnGC-R enhances antigen utilization, improves DC recruitment, and activates antigen-presenting cells. Single cell analysis of lymphocytes after intramuscular vaccination revealed that ZnGC-R generated multifaceted immune responses. ZnGC-R stimulated robust CD4+CCR7loPD-1hi Tfh and durable CD8+CD44hiCD62L- TEM immune responses, and simultaneously promoted the proliferation of CD26+ germinal center B cells. Besides, ZnGC-R elicited 2.53-fold higher hemagglutination-inhibiting antibody than commercial-licensed aluminum salt adjuvant. ZnGC-R based vaccine induced 342% stronger IgG antibody responses compared with vaccines with inactivated virus alone, leading to 100% in vivo protection efficacy against the H1N1 influenza virus challenge.

Low Immunogenicity of Keratinocytes Derived from Human Embryonic Stem Cells.

Epidermal transplantation is a common and widely used surgical technique in clinical medicine. Derivatives of embryonic stem cells have the potential to serve as a source of transplantable cells. However, allograft rejection is one of the main challenges. To investigate the immunogenicity of keratinocytes derived from human embryonic stem cells (ESKCs), we conducted a series of in vivo and in vitro experiments. The results showed that ESKCs have low HLA molecule expression, limited antigen presentation capabilities, and a weak ability to stimulate the proliferation and secretion of inflammatory factors in allogeneic PBMCs in vitro. In humanized immune mouse models, ESKCs elicited weak transplant rejection responses in the host. Overall, we found that ESKCs have low immunogenicity and may have potential applications in the field of regenerative medicine.

DEPDC1B is a Novel Direct Target of B-Myb and Contributes to Malignant Progression and Immune Infiltration in Lung Adenocarcinoma.

BACKGROUND: Lung cancer is the primary cause of cancer-related deaths, with one of the highest incidence and mortality rates of all malignant tumors. Dysregulated expression of DEPDC1B has been reported to occur in various tumor types. However, the functional implications of this alteration in lung adenocarcinoma (LUAD) and the underlying molecular mechanism remains unclear. In this study, we investigated the role and clinical significance of DEPDC1B in LUAD. METHODS: The expression of DEPDC1B in LUAD and its relationship with prognosis were systematically evaluated in several publically available datasets. The effects of DEPDC1B knockdown on the proliferation and motility of LUAD cells were assessed using the JULI Stage Real-time Cell History Recorder, while the effect of knockdown on the cell cycle was studied by flow cytometry. Furthermore, RNA-Sequencing (RNA-Seq) analysis was conducted to identify the downstream target genes and pathways regulated by DEPDC1B. Correlations between the expression of DEPDC1B and immune cell infiltration, immunotherapy resistance, and chemoresistance were also examined. Additionally, molecular biological methods were used to explore the regulatory mechanism of B-Myb on DEPDC1B expression. RESULTS: DEPDC1B was found to be upregulated in LUAD patients and this was associated with poor clinical outcomes. Knockdown of DEPDC1B inhibited cell growth, migration and motility, as well as cell cycle progression. Knockdown also resulted in the down-regulation of several downstream genes, including NID1, FN1, and EGFR, as well as the inactivation of multiple critical pathways, such as the ERK and PI3K-AKT pathways. Analysis of the tumor immuno-environment in LUAD revealed that high DEPDC1B expression was associated with an abundance of activated CD4+ memory T cells, M0 macrophages, M1 macrophages, and CD8+ T cells. Moreover, these tumors responded poorly to immunotherapy. Analysis of chemo-drug sensitivity showed that LUADs with high DEPDC1B expression were more responsive to frontline chemotherapeutic drugs such as Vinorelbine, Cisplatin, and Etoposide. Additionally, mechanistic investigations revealed that DEPDC1B is a direct target gene of B-Myb, and that its knockdown attenuated the proliferation and motility effects of B-Myb. CONCLUSIONS: In summary, our findings indicate that DEPDC1B is a critical regulator during the malignant progression of LUAD. DEPDC1B could therefore be a promising prognostic marker and therapeutic target in LUAD diagnosis and treatment.

Targeting the Ferroptosis and Endoplasmic Reticulum Stress Signaling Pathways by CBX7 in Myocardial Ischemia/reperfusion Injury.

Ferroptosis and endoplasmic reticulum stress (ERS) are common events in the process of myocardial ischemia/reperfusion injury (IRI). The suppression of chromobox7 (CBX7) has been reported to protect against ischemia/reperfusion injury, This research is purposed to expose the impacts and mechanism of CBX7 in myocardial IRI. CBX7 expression was detected using RT-qPCR and western blotting analysis. CCK-8 assay detected cell viability. Inflammatory response and oxidative stress were detected by ELISA, DCFH-DA probe and related assay kits. Flow cytometry analysis and caspase3 activity assay were used to detect cell apoptosis. C11-BODIPY 581/591 staining and ferro-orange staining were used to detect lipid reactive oxygen species (ROS) and Fe2+ level, respectively. Western blotting was used to detect the expression of proteins associated with apoptosis, ferroptosis and ERS. In the hypoxia/reoxygenation (H/R) model of rat cardiomyocytes H9c2, CBX7 was highly expressed. CBX7 interference significantly protected against inflammatory response, oxidative stress, apoptosis, ferroptosis and ERS induced by H/R in H9c2 cells. Moreover, after the pretreatment with ferroptosis activator erastin or ERS agonist Tunicamycin (TM), the protective effects of CBX7 knockdown on the inflammation, oxidative stress and apoptosis in H/R-induced H9c2 cells was partially abolished. To summarize, CBX7 down-regulation may exert anti-ferroptosis and anti-ERS activities to alleviate H/R-stimulated myocardial injury.

Single-cell sequencing reveals increased LAMB3-positive basal keratinocytes and ZNF90-positive fibroblasts in autologous cultured epithelium.

Autologous cultured epithelium grafting (ACEG) presents a promising treatment for refractory vitiligo, yet concerns regarding infections and immunological reactions hinder its surgical use due to serum and feeder dependencies. Addressing this, we culture autologous epithelium under serum- and feeder-free (SFF) conditions, comparing its safety and efficacy with serum- and feeder-dependent (SFD) conditions in stable vitiligo patients, and we discover no significant differences in repigmentation between the SFF and SFD grafts. Single-cell RNA transcriptomics on SFF- and SFD-cultured epithelium alongside healthy skin reveal increased populations of LAMB3+ basal keratinocytes and ZNF90+ fibroblasts in the SFF sheets. Functional analyses showcase active cellular metabolism in LAMB3+ basal keratinocytes, vital in extracellular matrix homeostasis, while ZNF90+ fibroblasts demonstrate increased differentiation, essential in collagen formation for cell adhesion. Importantly, these cell populations in SFF sheets exhibit enhanced interactions with melanocytes compared to SFD sheets. Further, knockdown experiments of LAMB3 in keratinocytes and ZNF90 in fibroblasts lead to a downregulation in melanocyte ligand-receptor-related genes. Overall, SFF sheets demonstrate comparable efficacy to SFD sheets, offering superior safety. LAMB3+ basal keratinocytes and ZNF90+ fibroblasts act as potential drivers behind repigmentation in ACEG under SFF conditions. This study provides translational insights into ACEG repigmentation and potential therapeutic targets for vitiligo.

Precise Design Strategies of Nanotechnologies for Controlled Drug Delivery.

Rapid advances in nanotechnologies are driving the revolution in controlled drug delivery. However, heterogeneous barriers, such as blood circulation and cellular barriers, prevent the drug from reaching the cellular target in complex physiologic environments. In this review, we discuss the precise design of nanotechnologies to enhance the efficacy, quality, and durability of drug delivery. For drug delivery in vivo, drugs loaded in nanoplatforms target particular sites in a spatial- and temporal-dependent manner. Advances in stimuli-responsive nanoparticles and carbon-based drug delivery platforms are summarized. For transdermal drug delivery systems, specific strategies including microneedles and hydrogel lead to a sustained release efficacy. Moreover, we highlight the current limitations of clinical translation and an incentive for the future development of nanotechnology-based drug delivery.

2'-O-Methyl modified guide RNA promotes the single nucleotide polymorphism (SNP) discrimination ability of CRISPR-Cas12a systems.

The CRISPR-Cas12a system has been widely applied to genome editing and molecular diagnostics. However, off-target cleavages and false-positive results remain as major concerns in Cas12a practical applications. Herein, we propose a strategy by utilizing the 2'-O-methyl (2'-OMe) modified guide RNA (gRNA) to promote the Cas12a's specificity. Gibbs free energy analysis demonstrates that the 2'-OMe modifications at the 3'-end of gRNA effectively suppress the Cas12a's overall non-specific affinity while maintaining high on-target affinity. For general application illustrations, HBV genotyping and SARS-CoV-2 D614G mutant biosensing platforms are developed to validate the enhanced Cas12a's specificity. Our results indicate that the 2'-OMe modified gRNAs could discriminate single-base mutations with at least two-fold enhanced specificity compared to unmodified gRNAs. Furthermore, we investigate the enhancing mechanisms of the 2'-OMe modified Cas12a systems by molecular docking simulations and the results suggest that the 2'-OMe modifications at the 3'-end of gRNA reduce the Cas12a's binding activity to off-target DNA. This work offers a versatile and universal gRNA design strategy for highly specific Cas12a system development.