The Prediction of LptA and LptC Protein-Protein Interactions and Virtual Screening for Potential Inhibitors.

Antibiotic resistance in Gram-negative bacteria remains one of the most pressing challenges to global public health. Blocking the transportation of lipopolysaccharides (LPS), a crucial component of the outer membrane of Gram-negative bacteria, is considered a promising strategy for drug discovery. In the transportation process of LPS, two components of the LPS transport (Lpt) complex, LptA and LptC, are responsible for shuttling LPS across the periplasm to the outer membrane, highlighting their potential as targets for antibacterial drug development. In the current study, a protein-protein interaction (PPI) model of LptA and LptC was constructed, and a molecular screening strategy was employed to search a protein-protein interaction compound library. The screening results indicated that compound 18593 exhibits favorable binding free energy with LptA and LptC. In comparison with the molecular dynamics (MD) simulations on currently known inhibitors, compound 18593 shows more stable target binding ability at the same level. The current study suggests that compound 18593 may exhibit an inhibitory effect on the LPS transport process, making it a promising hit compound for further research.

CXCR2 antagonist navarixin in combination with pembrolizumab in select advanced solid tumors: a phase 2 randomized trial.

C-X-C motif chemokine receptor 2 (CXCR2) has a role in tumor progression, lineage plasticity, and reduction of immune checkpoint inhibitor efficacy. Preclinical evidence suggests potential benefit of CXCR2 inhibition in multiple solid tumors. In this phase 2 study (NCT03473925), adults with previously treated advanced or metastatic castration-resistant prostate cancer (CRPC), microsatellite-stable colorectal cancer (MSS CRC), or non-small-cell lung cancer (NSCLC) were randomized 1:1 to the CXCR2 antagonist navarixin 30 or 100 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks up to 35 cycles. Primary endpoints were investigator-assessed objective response rate (RECIST v1.1) and safety. Of 105 patients (CRPC, n=40; MSS CRC, n=40; NSCLC, n=25), 3 had a partial response (2 CRPC, 1 MSS CRC) for ORRs of 5%, 2.5%, and 0%, respectively. Median progression-free survival was 1.8-2.4 months without evidence of a dose-response relationship, and the study was closed at a prespecified interim analysis for lack of efficacy. Dose-limiting toxicities occurred in 2/48 patients (4%) receiving navarixin 30 mg and 3/48 (6%) receiving navarixin 100 mg; events included grade 4 neutropenia and grade 3 transaminase elevation, hepatitis, and pneumonitis. Treatment-related adverse events occurred in 70/105 patients (67%) and led to treatment discontinuation in 7/105 (7%). Maximal reductions from baseline in absolute neutrophil count were 44.5%-48.2% (cycle 1) and 37.5%-44.2% (cycle 2) and occurred within 6-12 hours postdose in both groups. Navarixin plus pembrolizumab did not demonstrate sufficient efficacy in this study. Safety and tolerability of the combination were manageable. (Trial registration: ClinicalTrials.gov , NCT03473925).

Biomarker Testing Journey Among Patients with Advanced Solid Tumors and Treatment Patterns by Homologous Recombination Repair Status: A Clinico-Genomic Database Study.

INTRODUCTION: Defects in the homologous recombination repair (HRR) pathway can include mutations in BRCA1 and BRCA2 (BRCAm) and other HRR genes (HRRm). These mutations are associated with a homologous recombination deficiency (HRD) phenotype. We evaluated testing journey and treatment patterns by BRCAm, HRRm, and HRD status in a real-world dataset. METHODS: Deidentified data for patients who had undergone comprehensive genomic profiling using FoundationOne®CDx were collected through December 31, 2020, from a real-world multi-tumor clinico-genomic database (CGDB) capturing data from clinics in the United States. Patients eligible for inclusion in this analysis had a confirmed diagnosis with advanced or metastatic disease between January 1, 2018, and December 31, 2019, for 1 of 15 solid tumor types. Objectives were to evaluate patient treatment patterns by BRCAm, HRRm, and HRD status and to describe the timing of when (throughout disease course) comprehensive genomic profiling was performed. RESULTS: Among 9457 patients included in the overall population with evaluable biomarker status, 7856 (83.1%) received ≥ 1 systemic therapy. Among the 7856 patients who received systemic therapy, 2324 (30.0%) underwent testing before first-line therapy, 4114 (52.4%) were tested after receiving first-line therapy and before receiving subsequent therapy (if any), 970 (12.3%) were tested after second-line therapy and before receiving subsequent therapy (if any), and 447 (5.7%) patients underwent testing after receiving third-line therapy. A higher proportion of patients with BRCAm, HRRm, or HRD-positive status were treated with poly(ADP-ribose) polymerase (PARP) inhibitors across all lines of therapy. There was no evidence of a meaningful difference in the proportion of patients who received other treatment (including chemotherapy and immunotherapy) by BRCAm, HRRm, or HRD status. CONCLUSION: The majority of patients from this real-world dataset underwent FoundationOne®CDx testing after initiation of first-line treatment. Testing appeared to influence treatment patterns, with a higher proportion of patients with BRCAm, HRRm, and HRD-positive disease receiving PARP inhibitors.

Development of preimplantation genetic testing for monogenic diseases in China.

Preimplantation genetic testing for monogenic diseases (PGT-M) can effectively interrupt the transmission of genetic diseases from parents to the offspring before pregnancy. In China, there are over ten million individuals afflicted with monogenic disorders. This literature review summarizes the development of PGT-M in China for the past 24 years, covering the general steps such as the indications and contraindications, genetic and reproductive counselling, biopsy methods, detecting techniques and strategies during PGT-M application in China. The ethical considerations of PGT-M are also be emphasized, including sexual selection, transferring for mosaic embryos, the three-parent baby, and the different opinions for serious adult-onset conditions. Some key policies of the Chinese government for the application of PGT-M are also considered. Methods for regulation of this technique, as well as specific management to increase the accuracy and reliability of PGT-M, are regarded as priority issues in China. The third-generation sequencing and variants testing from RNA level, and non-invasive preimplantation genetic testing using blastocoel fluid and free DNA particles within spent blastocyst medium might be potential techniques and strategies for PGT-M in future.

Association Between Homologous Recombination Repair Biomarkers and Survival in Patients With Solid Tumors.

PURPOSE: Mutations in BRCA1 and/or BRCA2 (BRCAm), other homologous recombination repair genes (HRRm), and homologous recombination deficiency (HRD) lead to an accumulation of genomic alterations that can drive tumorigenesis. The prognostic impact of these HRR pathway defects on overall survival (OS) in patients not receiving poly (ADP-ribose) polymerase inhibitors (PARPi) or immunotherapy is unclear. We evaluated the association of HRR biomarkers with OS in patients with advanced solid tumors receiving therapy excluding PARPi and immunotherapy. METHODS: Deidentified data were collected through December 31, 2020, from a real-world clinicogenomic database (CGDB) with data originating from approximately 280 cancer clinics in the United States. Patients age 18 years and older with an advanced/metastatic diagnosis between 2018 and 2019 for 1 of 15 solid tumors and available data in the CGDB were included. The primary analysis evaluated the association between HRR pathway biomarkers and OS, using start of second-line therapy as the index date (to reduce immortal time bias). RESULTS: A total of 9,457 patients had available data for BRCA/HRR and 5,792 for HRD status; 4,890 (51.7%) were women and mean (SD) age was 65.9 (11.5) years. For the primary analysis, adjusted hazard ratios for OS were BRCAm (n = 156) versus BRCA wild-type (wt; n = 3,131; 0.83 [95% CI, 0.60 to 1.17]); for HRRm (n = 467) versus HRRwt (n = 282; 0.95 [95% CI, 0.79 to 1.14]); and for HRD-positive (n = 447) versus -negative (n = 1,687; 1.22 [95% CI, 1.02 to 1.47]). Results were similar using start of first-line and start of third-line therapy as index dates. CONCLUSION: This large, real-world study found no association between OS and either BRCA or HRR status but identified a possible linkage between HRD positivity and shorter median OS in patients with advanced solid tumors who did not receive PARPi or immunotherapy.

The impact of digital finance on SMEs financialization: Evidence from thirty million Chinese enterprise registrations.

Based on the registration information of 30 million Chinese enterprises, this study innovatively constructs a financialization index based on the text information of enterprise business scope. Then, the impact of digital finance on small and medium-sized enterprise (SME) financialization is examined. Specifically, this study screens out SMEs involved in financial transactions by counting the keyword information in their business scope. The level of SME financialization is measured at the provincial level, based on a large number of registration samples. Empirical results based on panel fixed effects show that digital finance significantly inhibits SME financialization. On average, for each standard deviation increase in digital finance, SME financialization decreases by 0.087 standard deviations. This conclusion remains valid after a series of robustness analyses. A mechanism analysis shows that digital finance inhibits SME financialization by alleviating financing constraints, especially by providing liquidity to SMEs with relatively high financing constraints. In addition, the risk consequences of SME financialization are further examined, and SME financialization is found to significantly increase bankruptcy risk, while digital finance alleviates financing constraints and thus reduces bankruptcy risk. This study provides a new perspective for the governance of SME financialization and the optimization of the survival environment for SMEs in the context of the digital economy.

Discovery of 2,4-diphenyl-substituted thiazole derivatives as PRMT1 inhibitors and investigation of their anti-cervical cancer effects.

Cervical cancer is one of the most common cancers that affects middle-aged women and the discovery of new drugs to aid clinical management is needed. As an important member of the protein arginine methyltransferases (PRMTs) family, PRMT1 catalyzes the methylation of protein arginine, which can influence multiple biological processes of cancer cells, such as activating epithelial-mesenchymal transformation (EMT) and acquiring resistance to apoptosis. Therefore, PRMT1 can be considered as a potential drug target for cervical cancer. In the current study, a new sub-binding pocket was discovered by molecular modeling, and by introducing a third substitute on the thiazole group to occupy this pocket, a series of compounds were designed and synthesized as potential PRMT1 inhibitors. Of these, two compounds (ZJG51 and ZJG58) exhibited significant inhibitory activities against PRMT1 without significantly inhibiting PRMT5. Both ZJG51 and ZJG58 displayed potent inhibitory effects on the proliferation of four cancer-derived cell lines and ZJG51 exerted relative selectivity against the cervical cancer cell line, HeLa. Further studies showed that ZJG51 inhibited migration and induce the apoptosis of HeLa cells. Mechanistically, ZJG51 significantly regulated PRMT1 related proteins, and indicated that the induction of apoptosis and inhibition of migration by ZJG51 may involve the activation of Caspase 9 and the inhibition of EMT, respectively. Molecular dynamic simulation and free energy calculation showed that ZJG51 can bind to PRMT1 stably and the binding mode was predicted. These data indicated that introducing the third substitute on the five-membered ring could be a future direction for structure-based optimization of PRMT1 inhibitors, and ZJG51 could be an important lead compound to inform the design of more potent inhibitors.

A novel compound to overcome influenza drug resistance in endonuclease inhibitors.

Influenza is a seasonal respiratory illness that kills hundreds of thousands of people every year. Currently, neuraminidase inhibitors and endonuclease inhibitors are used in antiviral therapy. However, both drug types have encountered drug-resistant influenza strains in the human body. Fortunately, there is currently no resistance to endonuclease inhibitors in wild strains of influenza. We obtained the molecules with endonuclease inhibitor activity independent of the existing drug-resistant strains through computer-aided drug design, and we hope the obtained results can lay a theoretical foundation for the development of high-activity endonucleases. Combining a traditional fragment-based drug discovery approach with AI-directed fragment growth, we selected and designed a compound that achieved antiviral activity on drug-resistant strains by avoiding mutable residues and drug-resistant residues. We predicted the related properties using an ADMET model. Finally, we obtained a compound similar to baloxavir in terms of binding free energy but not affected by baloxavir resistance.

Butein inhibits cancer cell growth by rescuing the wild-type thermal stability of mutant p53.

p53 is a transcription factor that activates the expression of various genes involved in the maintenance of genomic stability, and more than 50% of cancers harbor inactivating p53 mutations, which are indicative of highly aggressive cancer and poor prognosis. Pharmacological targeting of mutant p53 to restore the wild-type p53 tumor-suppressing function is a promising strategy for cancer therapy. In this study, we identified a small molecule, Butein, that reactivates mutant p53 activity in tumor cells harboring the R175H or R273H mutation. Butein restored wild-type-like conformation and DNA-binding ability in HT29 and SK-BR-3 cells harboring mutant p53-R175H and mutant p53-R273H, respectively. Moreover, Butein enabled the transactivation of p53 target genes and decreased the interactions of Hsp90 with mutant p53-R175H and mutant p53-R273H proteins, while Hsp90 overexpression reversed targeted p53 gene activation. In addition, Butein induced thermal stabilization of wild-type p53, mutant p53-R273H and mutant p53-R175H, as determined via CETSA. From docking study, we further proved that Butein binding to p53 stabilized the DNA-binding loop-sheet-helix motif of mutant p53-R175H and regulated its DNA-binding activity via an allosteric mechanism, conferring wild-type-like the DNA-binding activity of mutant p53. Collectively, the data suggest that Butein is a potential antitumor agent that restores p53 function in cancers harboring mutant p53-R273H or mutant p53-R175H. SIGNIFICANCE: Butein restores the ability of mutant p53 to bind DNA by reversing its transition to the Loop3 (L3) state, endows p53 mutants with thermal stability and re-establishes their transcriptional activity to induce cancer cell death.

Hybrid Metal-Organic Frameworks/Carbon Fibers Reinforcements for Additively Manufactured Composites.

Additively manufactured (AM) composites based on short carbon fibers possess strength and stiffness far less than their continuous fiber counterparts due to the fiber's small aspect ratio and inadequate interfaces with the epoxy matrix. This investigation presents a route for preparing hybrid reinforcements for AM that comprise short carbon fibers and nickel-based metal-organic frameworks (Ni-MOFs). The porous MOFs furnish the fibers with tremendous surface area. Additionally, the MOFs growth process is non-destructive to the fibers and easily scalable. This investigation also demonstrates the viability of using Ni-based MOFs as a catalyst for growing multi-walled carbon nanotubes (MWCNTs) on carbon fibers. The changes to the fiber were examined via electron microscopy, X-ray scattering techniques, and Fourier-transform infrared spectroscopy (FTIR). The thermal stabilities were probed by thermogravimetric analysis (TGA). Tensile and dynamic mechanical analysis (DMA) tests were utilized to explore the effect of MOFs on the mechanical properties of 3D-printed composites. Composites with MOFs exhibited improvements in stiffness and strength by 30.2% and 19.0%, respectively. The MOFs enhanced the damping parameter by 700%.

Opto-magnetic resonance single-beam magnetometer driven by vector polarized light.

In this paper, we present an analysis of the amplitude variations of the opto-magnetic resonance absorption signals obtained in a single-beam magnetometer driven by radially or azimuthally polarized light (RPL/APL). It is shown that optically polarized atoms driven by cylindrical vector beams obtained only the alignment of atomic multipole moments but not the orientation, which is in good agreement with our simulation and experimental results. In comparison with the plane polarized pump light fields, cylindrical vector beams with much more complete electric vector polarization distribution in the transverse plane, make it unlikely to create the "emptying state " (no-atom populated) among the ground-state Zeeman sublevels for any possible orientation of the applied static magnetic field. These characteristics of the RPL/APL lead to generally smaller atomic population difference and lower response intensity of the transmitted signal. The tensor decomposition of atomic polarized states and the evolution of atomic multipole moments with the sweeping radio frequency (RF) field offer the way to show the magnetic orientation sensitivity of the radially or azimuthally polarized probe light, which possess similar profiles as that of the linearly polarized light, only with a constant phase lag of about π/2 and obvious amplitude differences.

Phase 1b study of intravenous coxsackievirus A21 (V937) and ipilimumab for patients with metastatic uveal melanoma.

PURPOSE: No standard of care therapy exists for patients with metastatic uveal melanoma who are not HLA-A2:01 positive. The phase 1b, open-label CLEVER study (NCT03408587) evaluated V937 in combination with ipilimumab in patients with uveal melanoma. METHODS: Adults with advanced uveal melanoma and liver metastases received up to 8 cycles of intravenous V937 (1 × 109 TCID50 per infusion; infusions on days 1, 3, 5, and 8 [cycle 1], then every 3 weeks [Q3W] thereafter [cycles 2-8]) and 4 cycles of intravenous ipilimumab 3 mg/kg Q3W (beginning at cycle 1 day 8). The primary endpoint was safety. Secondary endpoints included objective response rate and progression-free survival (PFS) per immune-related Response Evaluation Criteria in Solid Tumors (irRECIST). RESULTS: Eleven patients were enrolled (median age, 65.0 years) and received a median of 6 injections of V937 and 3.5 infusions of ipilimumab. The best overall response was stable disease in 3 patients and progressive disease in 8 patients. All patients exhibited progression per irRECIST, with a 9% irPFS rate at week 26. Ten patients had treatment-related AEs, the most frequent of which were diarrhea (55%), fatigue (45%), and myalgia (36%). Two grade 3 AEs (diarrhea, n = 2) were considered related to ipilimumab; neither was related to V937. CONCLUSION: Although the combination of V937 with ipilimumab had a manageable safety profile, meaningful clinical benefit was not observed in patients with uveal melanoma and liver metastases. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03408587 (January 24, 2018).

Phase 1, open-label, dose-escalation study on the safety, pharmacokinetics, and preliminary efficacy of intravenous Coxsackievirus A21 (V937), with or without pembrolizumab, in patients with advanced solid tumors.

BACKGROUND: Oncolytic virus V937 showed activity and safety with intratumoral administration. This phase 1 study evaluated intravenous V937±pembrolizumab in patients with advanced solid tumors. METHODS: Patients had advanced non-small cell lung cancer (NSCLC), urothelial cancer, metastatic castration-resistant prostate cancer, or melanoma in part A (V937 monotherapy), and metastatic NSCLC or urothelial cancer in part B (V937+pembrolizumab). Prior immunotherapy was permitted >28 days before study treatment. Patients received intravenous V937 on days 1, 3, and 5 (also on day 8 in part B) of the first 21-day cycle and on day 1 of subsequent cycles for eight cycles. Three ascending dose-escalation cohorts were studied. Dose-escalation proceeded if no dose-limiting toxicities (DLTs) occurred in cycle 1 of the previous cohort. In part B, patients also received pembrolizumab 200 mg every 3 weeks from day 8 for 2 years; dose-expansion occurred at the highest-dose cohort. Serial biopsies were performed. RESULTS: No DLTs occurred in parts A (n=18) or B (n=85). Grade 3-5 treatment-related adverse events (AEs) were not observed in part A and were experienced by 10 (12%) patients in part B. The most frequent treatment-related AEs (any grade) in part B were fatigue (36%), pruritus (18%), myalgia (14%), diarrhea (13%), pyrexia (13%), influenza-like illness (12%), and nausea (12%). At the highest tested dose, median intratumoral V937 concentrations were 117,631 copies/mL on day 8, cycle 1 in part A (n=6) and below the detection limit for most patients (86% (19/22)) on day 15, cycle 1 in part B. Objective response rates were 6% (part A), 9% in the NSCLC dose-expansion cohort (n=43), and 20% in the urothelial cancer dose-expansion cohort (n=35). CONCLUSIONS: Intravenous V937+pembrolizumab had a manageable safety profile. Although V937 was detected in tumor tissue, in NSCLC and urothelial cancer, efficacy was not greater than that observed in previous studies with pembrolizumab monotherapy. TRIAL REGISTRATION NUMBER: NCT02043665.

A phase 1b single-arm trial of intratumoral oncolytic virus V937 in combination with pembrolizumab in patients with advanced melanoma: results from the CAPRA study.

BACKGROUND: CAPRA (NCT02565992) evaluated Coxsackievirus A21 (V937) + pembrolizumab for metastatic/unresectable stage IIIB-IV melanoma. METHODS: Patients received intratumoral V937 on days 1, 3, 5, and 8 (then every 3 weeks [Q3W]) and intravenous pembrolizumab 2 mg/kg Q3W from day 8. Primary endpoint was safety. RESULTS: Median time from first dose to data cutoff was 32.0 months. No dose-limiting toxicities occurred; 14% (5/36) of patients experienced grade 3‒5 treatment-related adverse events. Objective response rate was 47% (complete response, 22%). Among 17 responders, 14 (82%) had responses ≥ 6 months. Among 8 patients previously treated with immunotherapy, 3 responded (1 complete, 2 partial). Responses were associated with increased serum CXCL10 and CCL22, suggesting viral replication contributes to antitumor immunity. For responders versus nonresponders, there was no difference in baseline tumor PD-L1 expression, ICAM1 expression, or CD3+ infiltrates. Surprisingly, the baseline cell density of CD3+CD8- T cells in the tumor microenvironment was significantly lower in responders compared with nonresponders (P = 0.0179). CONCLUSIONS: These findings suggest responses to this combination may be seen even in patients without a typical "immune-active" microenvironment. TRIAL REGISTRATION NUMBER: NCT02565992.

The Anti-Multidrug-Resistant Acinetobacter baumannii Study on 1,3-diamino-7H-pyrrolo[3,2-f]quinazoline Compounds.

As a major public health problem, the prevalence of Acinetobacter baumannii (A. baumannii) infections in hospitals due to the pathogen's multiple-antibiotic resistance has attracted extensive attention. We previously reported a series of 1,3-diamino-7H-pyrrolo[3,2-f]quinazoline (PQZ) compounds, which were designed by targeting Escherichia coli dihydrofolate reductase (ecDHFR), and exhibited potent antibacterial activities. In the current study, based on our molecular-modeling study, it was proposed that PQZ compounds may function as potent A. baumannii DHFR (abDHFR)-inhibitors as well, which inspired us to consider their anti-A. baumannii abilities. We further found that three PQZ compounds, OYYF-171, -172, and -175, showed significant antibacterial activities against A. baumannii, including multidrug-resistant (MDR) strains, which are significantly stronger than the typical DHFR-inhibitor, trimethoprim (TMP), and superior to, or comparable to, the other tested antibacterial agents belonging to ß-lactam, aminoglycoside, and quinolone. The significant synergistic effect between the representative compound OYYF-171 and the dihydropteroate synthase (DHPS)-inhibitor sulfamethoxazole (SMZ) was observed in both the microdilution-checkerboard assay and time-killing assay, which indicated that using SMZ in combination with PQZ compounds could help to reduce the required dosage and forestall resistance. Our study shows that PQZ is a promising scaffold for the further development of folate-metabolism inhibitors against MDR A. baumannii.

Assessment of added activity of an antitumor agent.

An unprecedented number of novel oncology drugs are under preclinical and clinical development, and nearly all are developed in combinations. With an over-reliance on biological hypotheses, there is less effort to establish single agent activity before initiating late clinical development. This may be contributing to a decreased success rate going from phase 1 to approval in the immunotherapy era. Growing evidence in clinical trial data shows that the treatment benefit from most approved combination therapies can be explained by the independent drug action model. Using this working model, we develop a simple index to measure the added antitumor activity of a new drug based on mean response duration, an endpoint that naturally combines both response status and duration information for all patients, which is shown to be highly predictive of clinical benefit of FDA-approved anti-PD-(L)1 immunotherapies. This index sheds light on challenges and opportunities in contemporary oncology drug development and provides a practical tool to assist with decision-making in early clinical trials.

Primary specification of blastocyst trophectoderm by scRNA-seq: New insights into embryo implantation.

Mechanisms of implantation such as determination of the attachment pole, fetal-maternal communication, and underlying causes of implantation failure are largely unexplored. Here, we performed single-cell RNA sequencing on peri-implantation embryos from both humans and mice to explore trophectoderm (TE) development and embryo-endometrium cross-talk. We found that the transcriptomes of polar and mural TE diverged after embryos hatched from the zona pellucida in both species, with polar TE being more mature than mural TE. The implantation poles show similarities in cell cycle activities, as well as in expression of genes critical for implantation and placentation. Embryos that either fail to attach in vitro or fail to implant in vivo show abnormalities in pathways related to energy production, protein metabolism, and 18S ribosomal RNA m6A methylation. These findings uncover the gene expression characteristics of humans and mice TE differentiation during the peri-implantation period and provide new insights into embryo implantation.

Regional and developmental characteristics of human embryo mosaicism revealed by single cell sequencing.

Chromosomal mosaicism is common throughout human pre- and post-implantation development. However, the incidence and characteristics of mosaicism in human blastocyst remain unclear. Concerns and confusions still exist regarding the interpretation of chromosomal mosaicism on preimplantation genetic testing for aneuploidy (PGT-A) results and embryo development. Here, we aimed to estimate the genetic concordance between trophectoderm (TE), inner cell mass (ICM) and the corresponding human embryonic stem cells (hESCs), and to explore the characteristics of mosaicism in human blastocyst and hESCs on a single cell level. The single cell sequencing results of TE cells indicated that 65.71% of the blastocysts were mosaic (23 in 35 embryos), while the ICM sequencing results suggested that 60.00% of the blastocysts were mosaic (9 in 15 embryos). The incidence of mosaicism for the corresponding hESCs was 33.33% (2 in 6 embryos). No significant difference was observed between the mosaic rate of TE and that of ICM. However, the mosaic rate of the corresponding hESCs was significantly lower than that of TE and ICM cells, suggesting that the incidence of mosaicism may decline during embryonic development. Upon single cell sequencing, we found several "complementary" copy number variations (CNVs) that were usually not revealed in clinical PGT-A which used multi-cell DNA sequencing (or array analysis). This indicates the potential diagnostic risk of PGT-A based multi-cell analysis routinely in clinical practice. This study provided new insights into the characteristics, and considerable influences, of mosaicism on human embryo development, as well as the clinical risks of PGT-A based on multi-cell biopsies and bulk DNA assays.

Recyclability of Vitrimer Materials: Impact of Catalyst and Processing Conditions.

With sustainability at the forefront of material research, recyclable polymers, such as vitrimers, have garnered increasing attention since their introduction in 2011. In addition to a traditional glass-transition temperature (T g), vitrimers have a second topology freezing temperature (T v) above which dynamic covalent bonds allow for rapid stress relaxation, self-healing, and shape reprogramming. Herein, we demonstrate the self-healing, shape memory, and shape reconfigurability properties as a function of experimental conditions, aiming toward recyclability and increased useful lifetime of the material. Of interest, we report the influence of processing conditions, which makes the material vulnerable to degradation. We report a decreased crosslink density with increased thermal cycling and compressive stress. Furthermore, we demonstrate that shape reconfigurability and self-healing are enhanced with increasing compressive stress and catalyst concentration, while their performance as a shape memory material remains unchanged. Though increasing the catalyst concentration, temperature, and compressive stress clearly enhances the recovery performance of vitrimers, we must emphasize its trade-off when considering the material degradation reported here. While vitrimers hold great promise as structural materials, it is vital to understand how experimental parameters impact their properties, stability, and reprocessability before vitrimers reach their true potential.