An injectable hydrogel loaded with GMSCs-derived neural lineage cells promotes recovery after stroke.

Ischemic stroke is a devastating medical condition with poor prognosis due to the lack of effective treatment modalities. Transplantation of human neural stem cells or primary neural cells is a promising treatment approach, but this is hindered by limited suitable cell sources and low in vitro expansion capacity. This study aimed i) to use small molecules to reprogram gingival mesenchymal stem cells (GMSCs) commitment to the neural lineage cells in vitro, and ii) to use hyaluronic acid (HA) hydrogel scaffolds seeded with GMSCs-derived neural lineage cells to treat ischemic stroke invivo. Neural induction was carried out with a small molecule cocktail-based one-step culture protocol over a period of 24 hours. The induced cells were analyzed for expression of neural markers with immunocytochemistry and qRT-PCR. The SD rats (n=100) were subjected to the middle cerebral artery occlusion (MCAO) reperfusion ischemic stroke model. Then, after 8 days post-MCAO, the modelled rats were randomly assigned to six study groups (n=12 per group): (i) GMSCs, (ii) GMSCs-derived neural lineage cells, (iii) HA and GMSCs-derived neural lineage cells, (iv) HA, (v) PBS, and (vi) sham transplantation control, and received their respective transplantation. Evaluation of post-stroke recovery were performed by the behavioral tests and histological assessments. The morphologically altered nature of neural lineages has been observed of the GMSCs treated with small molecules compared to the untreated controls. As shown by the qRT-PCR and immunocytochemistry, small molecules further signifcantly enhanced the experession level of neural markers of GMSCs as compared with the untreated controls (all p<0.05). Intracerebral injection of self-assembling HA hydrogel carrying GMSCs-derived neural lineage cells promoted the recovery of neural function and reduced ischemic damage in rats with ischemic stroke, as demonstrated by histological examination and behavioral assessments (all p<0.05). In conclusion, the small molecule cocktail significantly enhanced the differentiation of GMSCs into neural lineage cells. The HA hydrogel was found to facilitate the proliferation and differentiation of GMSCs-derived neural lineage cells. Furthermore, HA hydrogel seeded with GMSCs-derived neural lineage cells could promote tissue repair and functional recovery in rats with ischemic stroke and may be a promising alternative treatment modality for stroke.

Super-resolution imaging for in situ monitoring sub-cellular micro-dynamics of small molecule drug.

Small molecule drugs play a pivotal role in the arsenal of anticancer pharmacological agents. Nonetheless, their small size poses a challenge when directly visualizing their localization, distribution, mechanism of action (MOA), and target engagement at the subcellular level in real time. We propose a strategy for developing triple-functioning drug beacons that seamlessly integrate therapeutically relevant bioactivity, precise subcellular localization, and direct visualization capabilities within a single molecular entity. As a proof of concept, we have meticulously designed and constructed a boronic acid fluorescence drug beacon using coumarin-hemicyanine (CHB). Our CHB design includes three pivotal features: a boronic acid moiety that binds both adenosine triphosphate (ATP) and adenosine diphosphate (ADP), thus depleting their levels and disrupting the energy supply within mitochondria; a positively charged component that targets the drug beacon to mitochondria; and a sizeable conjugated luminophore that emits fluorescence, facilitating the application of structured illumination microscopy (SIM). Our study indicates the exceptional responsiveness of our proof-of-concept drug beacon to ADP and ATP, its efficacy in inhibiting tumor growth, and its ability to facilitate the tracking of ADP and ATP distribution around the mitochondrial cristae. Furthermore, our investigation reveals that the micro-dynamics of CHB induce mitochondrial dysfunction by causing damage to the mitochondrial cristae and mitochondrial DNA. Altogether, our findings highlight the potential of SIM in conjunction with visual drug design as a potent tool for monitoring the in situ MOA of small molecule anticancer compounds. This approach represents a crucial advancement in addressing a current challenge within the field of small molecule drug discovery and validation.

Salmonella manipulates macrophage migration via SteC-mediated myosin light chain activation to penetrate the gut-vascular barrier.

The intestinal pathogen Salmonella enterica rapidly enters the bloodstream after the invasion of intestinal epithelial cells, but how Salmonella breaks through the gut-vascular barrier is largely unknown. Here, we report that Salmonella enters the bloodstream through intestinal CX3CR1+ macrophages during early infection. Mechanistically, Salmonella induces the migration/invasion properties of macrophages in a manner dependent on host cell actin and on the pathogen effector SteC. SteC recruits host myosin light chain protein Myl12a and phosphorylates its Ser19 and Thr20 residues. Myl12a phosphorylation results in actin rearrangement, and enhanced migration and invasion of macrophages. SteC is able to utilize a wide range of NTPs other than ATP to phosphorylate Myl12a. We further solved the crystal structure of SteC, which suggests an atypical dimerization-mediated catalytic mechanism. Finally, in vivo data show that SteC-mediated cytoskeleton manipulation is crucial for Salmonella breaching the gut vascular barrier and spreading to target organs.

Silencing circATXN1 in Aging Nucleus Pulposus Cell Alleviates Intervertebral Disc Degeneration via Correcting Progerin Mislocalization.

Circular RNAs (circRNAs) play a critical regulatory role in degenerative diseases; however, their functions and therapeutic applications in intervertebral disc degeneration (IVDD) have not been explored. Here, we identified that a novel circATXN1 highly accumulates in aging nucleus pulposus cells (NPCs) accountable for IVDD. CircATXN1 accelerates cellular senescence, disrupts extracellular matrix organization, and inhibits mitochondrial respiration. Mechanistically, circATXN1, regulated by heterogeneous nuclear ribonucleoprotein A2B1-mediated splicing circularization, promotes progerin translocation from the cell nucleus to the cytoplasm and inhibits the expression of insulin-like growth factor 1 receptor (IGF-1R). To demonstrate the therapeutic potential of circATXN1, siRNA targeting the backsplice junction of circATNX1 was screened and delivered by tetrahedral framework nucleic acids (tFNAs) due to their unique compositional and tetrahedral structural features. Our siRNA delivery system demonstrates superior abilities to transfect aging cells, clear intracellular ROS, and enhanced biological safety. Using siRNA-tFNAs to silence circATXN1, aging NPCs exhibit reduced mislocalization of progerin in the cytoplasm and up-regulation of IGF-1R, thereby demonstrating a rejuvenated cellular phenotype and improved mitochondrial function. In vivo, administering an aging cell-adapted siRNA nucleic acid framework delivery system to progerin pathologically expressed premature aging mice (zmpste24-/-) can ameliorate the cellular matrix in the nucleus pulposus tissue, effectively delaying IVDD. This study not only identified circATXN1 functioning as a cell senescence promoter in IVDD for the first time, but also successfully demonstrated its therapeutic potential via a tFNA-based siRNA delivery strategy.

A Curcumin-Decorated Nanozyme with ROS Scavenging and Anti-Inflammatory Properties for Neuroprotection.

Disordered reactive oxygen/nitrogen species are a common occurrence in various diseases, which usually cause cellular oxidative damage and inflammation. Despite the wide range of applications for biomimetic nanoparticles with antioxidant or anti-inflammatory properties, designs that seamlessly integrate these two abilities with a synergistic effect in a simple manner are seldom reported. In this study, we developed a novel PEI-Mn composite nanoparticle (PM NP) using a chelation method, and the curcumin was loaded onto PM NPs via metal-phenol coordination to form PEI-Mn@curcumin nanoparticles (PMC NPs). PMC NPs possessed excellent dispersibility and cytocompatibility, was engineered to serve as an effective nanozyme, and exhibited specific SOD-like and CAT-like activities. In addition, the incorporation of curcumin granted PMC NPs the ability to effectively suppress the expression of inflammatory cytokines in microglia induced by LPS. As curcumin also has antioxidant properties, it further amplified the synergistic efficiency of ROS scavenging. Significantly, PMC NPs effectively scavenged ROS triggered by H2O2 in SIM-A9 microglia cells and Neuro-2a cells. PMC NPs also considerably mitigated DNA and lipid oxidation in Neuro-2a cells and demonstrated an increase in cell viability under various H2O2 concentrations. These properties suggest that PMC NPs have significant potential in addressing excessive ROS and inflammation related to neural diseases.

Rosuvastatin Enhances Lymphangiogenesis after Myocardial Infarction by Regulating the miRNAs/Vascular Endothelial Growth Factor Receptor 3 (miRNAs/VEGFR3) Pathway.

BACKGROUND: Several clinical studies have suggested that the early administration of statins could reduce the risk of in-hospital mortality in acute myocardial infarction (AMI) patients. Recently, some studies have identified that stimulating lymphangiogenesis after AMI could improve cardiac function by reducing myocardial edema and inflammation. This study aimed to identify the effect of rosuvastatin on postinfarct lymphangiogenesis and to identify the underlying mechanism of this effect. METHOD: Myocardial infarction (MI) was induced by ligation of the left anterior descending coronary artery in mice orally administered rosuvastatin for 7 days. The changes in cardiac function, pathology, and lymphangiogenesis following MI were measured by echocardiography and immunostaining. EdU, Matrigel tube formation, and scratch wound assays were used to evaluate the effect of rosuvastatin on the proliferation, tube formation, and migration of the lymphatic endothelial cell line SVEC4-10. The expression of miR-107-3p, miR-491-5p, and VEGFR3 was measured by polymerase chain reaction (PCR) and Western blotting. A gain-of-function study was performed using miR-107-3p and miR-491-5p mimics. RESULTS: The rosuvastatin-treated mice had a significantly improved ejection fraction and increased lymphatic plexus density 7 days after MI. Rosuvastatin also reduced myocardial edema and inflammatory response after MI. We used a VEGFR3 inhibitor to partially reverse these effects. Rosuvastatin promoted the proliferation, migration, and tube formation of SVEC4-10 cells. PCR and Western blot analyses revealed that rosuvastatin intervention downregulated miR-107-3p and miR-491-5p and promoted VEGFR3 expression. The gain-of-function study showed that miR-107-3p and miR-491-5p could inhibit the proliferation, migration, and tube formation of SVEC4-10 cells. CONCLUSION: Rosuvastatin could improve heart function by promoting lymphangiogenesis after MI by regulating the miRNAs/VEGFR3 pathway.

Dynamics studies for the multi-well and multi-channel reaction of OH with C2H2 on a full-dimensional global potential energy surface.

The C2H2 + OH reaction is an important acetylene oxidation pathway in the combustion process, as well as a typical multi-well and multi-channel reaction. Here, we report an accurate full-dimensional machine learning-based potential energy surface (PES) for the C2H2 + OH reaction at the UCCSD(T)-F12b/cc-pVTZ-F12 level, based on about 475 000 ab initio points. Extensive quasi-classical trajectory (QCT) calculations were performed on the newly developed PES to obtain detailed dynamic data and analyze reaction mechanisms. Below 1000 K, the C2H2 + OH reaction produces H + OCCH2 and CO + CH3. With increasing temperature, the product channels H2O + C2H and H + HCCOH are accessible and the former dominates above 1900 K. It is found that the formation of H2O + C2H is dominated by a direct reaction process, while other channels belong to the indirect mechanism involving long-lived intermediates along the reaction pathways. At low temperatures, the C2H2 + OH reaction behaves like an unimolecular reaction due to the unique PES topographic features, of which the dynamic features are similar to the decomposition of energy-rich complexes formed by C2H2 + OH collision. The classification of trajectories that undergo different reaction pathways to generate each product and their product energy distributions were also reported in this work. This dynamic information may provide a deep understanding of the C2H2 + OH reaction.

A novel rat model of annulus fibrosus injury for intervertebral disc degeneration.

BACKGROUND CONTEXT: In clinical practice, acute trauma and chronic degeneration of the annulus fibrosus (AF) can promote further degeneration of the intervertebral disc (IVD). Therefore, it is critical to understand the AF repair process and its consequences on IVD. However, the lack of cost-effective and reproducible in vivo animal models of AF injury has limited research development in this field. PURPOSES: The purpose of this study was to establish and evaluate the utility of a novel animal model for full-thickness AF injury. Three foci were proposed: (1) whether this new modeling method can cause full-layer AF damage; (2) the repair processes and pathological changes in the damaged area after AF injury, and (3) the morphological and histological changes in the IVD are after AF injury. STUDY DESIGN/SETTING: In vivo rat AF injury model with characterization of AF damage repair, IVD degeneration. METHODS: A total of 72,300 g male rats were randomly assigned to one of the two groups: experimental or sham. Annulus fibrosus was separated layer by layer under the microscope with a #11 blade up to the AF- nucleus pulpous (NP) junction. The repair process of the horizontal AF and morphological changes in the sagittal IVD were evaluated with HE staining. Sirius red staining under polarized light. Immunofluorescence was conducted to analyze changes in the expression of COL1 and COL3 in the AF injury area and 8-OHdg, IL-6, MMP13, FSP1, and ACAN in the IVD. The disc height and structural changes after AF injury were measured using X-ray and contrast-enhanced micro-CT. Additionally, the resistance of the AF to stretching was analyzed using three-point bending. RESULTS: Annulus fibrosus-nucleus pulpous border was identified to stably induce the full-thickness AF injury without causing immediate NP injury. The AF repair process after injury was slow and expressed inflammation factors continuously, with abundant amounts of type III collagen appearing in the inner part of the AF. The scar at the AF lesion had decreased resistance to small molecule penetration and weakened tensile strength. Full-thickness AF injury induced disc degeneration with loss of disc height, progressive unilateral vertebral collapse, and ossification of the subchondral bone. Inflammatory-induced degeneration and extracellular matrix catabolism gradually appeared in the NP and cartilage endplate (CEP). CONCLUSIONS: We established a low-cost and reproducible small animal model of AF injury which accurately replicated the pathological state of the limited AF self-repair ability and demonstrated that injury to the AF alone could cause further degeneration of the IVD. CLINICAL RELEVANCE: This in vivo rat model can be used to study the repair process of the AF defect and pathological changes in the gradual degeneration of IVD after AF damage. In addition, the model provides an experimental platform for in vivo experimental research of potential clinical therapeutics.

Comparison of Intraoperative Endplate Injury between Mini-Open Lateral Lumbar Interbody Fusion (LLIF) and Transforaminal Lumbar Interbody Fusion (TLIF) and Analysis of Risk Factors: A Retrospective Study.

OBJECTIVE: The study aimed to compare the incidence of intraoperative endplate injury in patients who underwent Transforaminal interbody fusion (TLIF) and mini-open lumbar interbody fusion (LLIF) surgery. The independent risk factors related to endplate injury in LLIF procedure were analyzed. METHODS: A total of 199 patients who underwent LLIF (n = 106) or TLIF (n = 93) surgery from June 2019 to September 2021 were reviewed. The endplate injury was assessed by postoperative sagittal CT scan. A binary logistic analysis model were used to identify independent risk factors related to LLIF endplate injury based on univariate analysis. RESULTS: There was an obvious difference in the occurrence of intraoperative endplate injury between LLIF (42/106, 39.6%) and TLIF group (26/93, 28%), although it did not reach the significant level. L1 CT value (OR = 0.985, 95% CI = 0.972-0.998), cage position (OR = 3.881, 95% CI = 1.398-10.771) and height variance (OR = 1.263, 95% CI = 1.013-1.575) were independent risk factors for endplate injury in LLIF procedure. According to the cage settlement patterns, there 5 types of A to E. The severity of the facet joint degeneration was positively related to the occurrence of endplate injury. CONCLUSIONS: The incidence of intraoperative endplate injury is higher in LLIF than in TLIF procedures. Low bone quantity, cage posterior position and larger height variance are risk factors to induce endplate injury in LLIF surgery. The facet joint degeneration may be related to severe endplate injuries and even fractures.

Mitochondrial nucleoid condensates drive peripheral fission through high membrane curvature.

Mitochondria are dynamic organelles that undergo fusion and fission events, in which the mitochondrial membrane and DNA (mtDNA) play critical roles. The spatiotemporal organization of mtDNA reflects and impacts mitochondrial dynamics. Herein, to study the detailed dynamics of mitochondrial membrane and mtDNA, we rationally develop a dual-color fluorescent probe, mtGLP, that could be used for simultaneously monitoring mitochondrial membrane and mtDNA dynamics via separate color outputs. By combining mtGLP with structured illumination microscopy to monitor mitochondrial dynamics, we discover the formation of nucleoid condensates in damaged mitochondria. We further reveal that nucleoid condensates promoted the peripheral fission of damaged mitochondria via asymmetric segregation. Through simulations, we find that the peripheral fission events occurred when the nucleoid condensates interacted with the highly curved membrane regions at the two ends of the mitochondria. Overall, we show that mitochondrial nucleoid condensates utilize peripheral fission to maintain mitochondrial homeostasis.

A dense SERS substrate of the AgNPs@GO compound film for detecting homocysteine molecules.

This study focuses on the development of a highly sensitive surface-enhanced Raman scattering (SERS) sensor for detecting homocysteine (Hcy) molecules. The Hcy sensor was created by depositing silver nanoparticles (AgNPs) onto the surface of graphene oxide (GO) film to form a dense AgNPs@GO composite film. The AgNPs on the composite film interacted with sulfur atoms (S) of Hcy molecules to form Ag-S bonds, which boosted the chemisorption of Hcy molecules and enabled them to be specifically recognized. The SERS sensor exhibited a maximum enhancement factor of up to 1.1 × 104, with a reliable linear response range from 1 to 60 ng mL-1. The limit of detection (LOD) for Hcy molecules was as low as 1.1 × 10-9 M. Moreover, Hcy molecules were successfully distinguished in a mixed solution of γ-aminobutyric acid and Hcy molecules. In this study, a simple preparation process of SERS substrate and a novel detection method for Hcy molecules provided a new pathway for the rapid and effective detection of Hcy molecules in the food and biomedicine fields.

Thermosensitive hydrogel-based GPR124 delivery strategy for rebuilding blood-spinal cord barrier.

Spinal cord injury (SCI) causes blood-spinal cord barrier (BSCB) disruption, leading to secondary damage, such as hemorrhagic infiltration, inflammatory response, and neuronal cell death. It is of great significance to rebuild the BSCB at the early stage of SCI to alleviate the secondary injury for better prognosis. Yet, current research involved in the reconstruction of BSCB is insufficient. Accordingly, we provide a thermosensitive hydrogel-based G protein-coupled receptor 124 (GPR124) delivery strategy for rebuilding BSCB. Herein, we firstly found that the expression of GPR124 decreased post-SCI and demonstrated that treatment with recombinant GPR124 could partially alleviate the disruption of BSCB post-SCI by restoring tight junctions (TJs) and promoting migration and tube formation of endothelial cells. Interestingly, GPR124 could also boost the energy metabolism of endothelial cells. However, the absence of physicochemical stability restricted the wide usage of GPR124. Hence, we fabricated a thermosensitive heparin-poloxamer (HP) hydrogel that demonstrated sustained GPR124 production and maintained the bioactivity of GPR124 (HP@124) for rebuilding the BSCB and eventually enhancing functional motor recovery post-SCI. HP@124 hydrogel can encapsulate GPR124 at the lesion site by injection, providing prolonged release, preserving wounded tissues, and filling injured tissue cavities. Consequently, it induces synergistically efficient integrated regulation by blocking BSCB rupture, decreasing fibrotic scar formation, minimizing inflammatory response, boosting remyelination, and regenerating axons. Mechanistically, giving GPR124 activates energy metabolism via elevating the expression of phosphoenolpyruvate carboxykinase 2 (PCK2), and eventually restores the poor state of endothelial cells. This research demonstrated that early intervention by combining GPR124 with bioactive multifunctional hydrogel may have tremendous promise for restoring locomotor recovery in patients with central nervous system disorders, in addition to a translational approach for the medical therapy of SCI.

Controlled extracellular vesicles release from aminoguanidine nanoparticle-loaded polylysine hydrogel for synergistic treatment of spinal cord injury.

Pharmaceutical treatments are critical for the acute and subacute phases of spinal cord injury (SCI) and significantly impact patients' prognoses. However, there is a lack of a precise, multitemporal, integrated drug delivery system for medications administered in both phases. In this study, we prepare a hybrid polylysine-based hydrogel (PBHEVs@AGN) comprising short-term release of pH-responsive aminoguanidine nanoparticles (AGN) and sustained release of extracellular vesicles (EVs) for synergistic SCI treatment. When AGN is exposed to the acidic environment at the injury site, it quickly diffuses out of the hydrogel and releases the majority of the aminoguanidine within 24 h, reducing oxidative stress in lesion tissues. Enriched EVs are gradually released from the hydrogel and remain in the tissue for weeks, providing a long-term anti-inflammatory effect and further ensuring axonal regeneration. Fast-releasing aminoguanidine can cooperate with slow-release EVs to treat SCI more effectively by reducing the production of proinflammatory cytokines and blocking the TLR4/Myd88/NF-κB inflammatory pathway, creating a sustained anti-inflammatory microenvironment for SCI recovery. Our in vivo experiments demonstrate that PBHEVs@AGN reduces the occurrence of scar tissue, encourages remyelination, and speeds up axonal regeneration. Herein, this multi-drug delivery system, which combines the acute release of aminoguanidine and the sustained release of EVs is highly effective for synergistically managing the challenging pathological processes after SCI.

Subcellular visualization: Organelle-specific targeted drug delivery and discovery.

Organelles perform critical biological functions due to their distinct molecular composition and internal environment. Disorders in organelles or their interacting networks have been linked to the incidence of numerous diseases, and the research of pharmacological actions at the organelle level has sparked pharmacists' interest. Currently, cell imaging has evolved into a critical tool for drug delivery, drug discovery, and pharmacological research. The introduction of advanced imaging techniques in recent years has provided researchers with richer biological information for viewing and studying the ultrastructure of organelles, protein interactions, and gene transcription activities, leading to the design and delivery of precision-targeted drugs. Therefore, this reviews the research on organelles-targeted drugs based upon imaging technologies and development of fluorescent molecules for medicinal purposes. We also give a thorough analysis of a number of subcellular-level elements of drug development, including subcellular research instruments and methods, organelle biological event investigation, subcellular target and drug identification, and design of subcellular delivery systems. This review will make it possible to promote drug research from the individual/cellular level to the subcellular level, as well as give a new focus based on newly found organelle activities.

Reversible Recognition-Based Boronic Acid Probes for Glucose Detection in Live Cells and Zebrafish.

Glucose, a critical source of energy, directly determines the homeostasis of the human body. However, due to the lack of robust imaging probes, the mechanism underlying the changes of glucose homeostasis in the human body remains unclear. Herein, diboronic acid probes with good biocompatibility and high sensitivity were synthesized based on an ortho-aminomethylphenylboronic acid probe, phenyl(di)boronic acid (PDBA). Significantly, by introducing the water-solubilizing group -CN directly opposite the boronic acid group and -COOCH3 or -COOH groups to the ß site of the anthracene in PDBA, we obtained the water-soluble probe Mc-CDBA with sensitive response (F/F0 = 47.8, detection limit (LOD) = 1.37 µM) and Ca-CDBA with the highest affinity for glucose (Ka = 4.5 × 103 M-1). On this basis, Mc-CDBA was used to identify glucose heterogeneity between normal and tumor cells. Finally, Mc-CDBA and Ca-CDBA were used for imaging glucose in zebrafish. Our research provides a new strategy for designing efficient boronic acid glucose probes and powerful new tools for the evaluation of glucose-related diseases.

Metabolic Glycoengineering: A Promising Strategy to Remodel Microenvironments for Regenerative Therapy.

Cell-based regenerative therapy utilizes the differentiation potential of stem cells to rejuvenate tissues. But the dynamic fate of stem cells is calling for precise control to optimize their therapeutic efficiency. Stem cell fate is regulated by specific conditions called "microenvironments." Among the various factors in the microenvironment, the cell-surface glycan acts as a mediator of cell-matrix and cell-cell interactions and manipulates the behavior of cells. Herein, metabolic glycoengineering (MGE) is an easy but powerful technology for remodeling the structure of glycan. By presenting unnatural glycans on the surface, MGE provides us an opportunity to reshape the microenvironment and evoke desired cellular responses. In this review, we firstly focused on the determining role of glycans on cellular activity; then, we introduced how MGE influences glycosylation and subsequently affects cell fate; at last, we outlined the application of MGE in regenerative therapy, especially in the musculoskeletal system, and the future direction of MGE is discussed.

Nucleus pulposus cell-derived efficient microcarrier for intervertebral disc tissue engineering.

Adipose-derived stem cells (ADSCs) show great potential for the treatment of intervertebral disc (IVD) degeneration. An ideal carrier is necessary to transplant ADSCs into degenerated IVDs without influencing cell function. Nucleus pulposus cells (NPCs) can synthesize and deposit chondroitin sulfate and type II collagen which are NP-specific extracellular matrix (ECM) and can also regulate the NP-specific differentiation of stem cells. Bioscaffolds fabricated based on the ECM synthesis functions of NPCs have possible roles in cell transplantation and differentiation induction, but it has not been studied. In this study, we first aggregated NPCs into pellets, and then, NPC-derived efficient microcarriers (NPCMs) were fabricated by pellet cultivation under specific conditions and optimized decellularization. Thirdly, we evaluated the microstructure, biochemical composition, biostability and cytotoxicity of the NPCMs. Finally, we investigated the NP-specific differentiation of ADSCs induced by the NPCMsin vitroand NP regeneration induced by the ADSC-loaded NPCMs in a rabbit model. The results indicated that the injectable NPCMs retained maximal ECM and minimal cell nucleic acid after optimized decellularization and had good biostability and no cytotoxicity. The NPCMs also promoted the NP-specific differentiation of ADSCsin vitro. In addition, the results of MRI, x-ray, and the structure and ECM content of NP showed that the ADSCs-loaded NPCMs can partly restored the degenerated NPin vivo. Our injectable NPCMs regenerated the degenerated NP and provide a simplified and efficient strategy for treating IVD degeneration.

Avelumab Maintenance Treatment After First-line Chemotherapy in Advanced Urothelial Carcinoma-A Cost-Effectiveness Analysis.

BACKGROUND: Recently, a clinical trial (NCT02603432) showed that avelumab maintenance treatment, post first-line chemotherapy, can significantly prolong the overall survival of patients with advanced urothelial carcinoma (UC), however, the treatment was very expensive. This study aimed to determine the cost-effectiveness of avelumab maintenance therapy in advanced or metastatic UC from the US taxpayer perspective. METHODS: Based on the data of the JAVELIN Bladder 100 clinical trial (NCT02603432), a Markov multi-state model was constructed to investigate the costs and clinical outcomes of avelumab maintenance after platinum-based chemotherapy versus best supportive care (BSC) for advanced or metastatic UC. Parameters of the model came from the 2020 Average Sales Price Drug Pricing Files and published literature. The main outputs were costs, life years (LYs), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Robustness was tested by deterministic and probabilistic sensitivity analyses. The analysis was stratified to include both the overall population and a subset of programmed death-ligand 1 (PD-L1)-positive patients. RESULTS: Avelumab maintenance therapy was estimated to generate an additional 0.26 QALYs (1.46 vs. 1.20 QALYs) and costs $183,271 ($278,323 vs. $95,052) more compared to BSC alone in the overall population, yielding an ICER of $699,065/QALY. For the PD-L1-positive population, avelumab produced a 0.42 increase in QALYs (1.74 vs. 1.32 QALYs) and raised costs to $223,238 ($320,355 vs. $97,117), resulting in an ICER of $521,850/QALY for this population. Both ICERs were above the willingness-to-pay (WTP) threshold of $200,000/QALY. Sensitivity analyses manifested that the model was robust. CONCLUSION: From the perspective of the US taxpayer, avelumab maintenance therapy is considered cost-ineffective for patients with advanced or metastatic UC at a WTP threshold of $200,000/QALY in the overall population as well as in PD-L1-positive population.

Swelling-Mediated Mechanical Stimulation Regulates Differentiation of Adipose-Derived Mesenchymal Stem Cells for Intervertebral Disc Repair Using Injectable UCST Microgels.

Mechanical stimulation is an effective approach for controlling stem cell differentiation in tissue engineering. However, its realization in in vivo tissue repair remains challenging since this type of stimulation can hardly be applied to injectable seeding systems. Here, it is presented that swelling of injectable microgels can be transformed to in situ mechanical stimulation via stretching the cells adhered on their surface. Poly(acrylamide-co-acrylic acid) microgels with the upper critical solution temperature property are fabricated using inverse emulsion polymerization and further coated with polydopamine to increase cell adhesion. Adipose-derived mesenchymal stem cells (ADSCs) adhered on the microgels can be omnidirectionally stretched along with the responsive swelling of the microgels, which upregulate TRPV4 and Piezo1 channel proteins and enhance nucleus pulposus (NP)-like differentiation of ADSCs. In vivo experiments reveal that the disc height and extracellular matrix content of NP are promoted after the implantation with the microgels. The findings indicate that swelling-induced mechanical stimulation has great potential for regulating stem cell differentiation during intervertebral disc repair.

An ER-targeted "reserve-release" fluorogen for topological quantification of reticulophagy.

The endoplasmic reticulum's (ER) dynamic nature, essential for maintaining cellular homeostasis, can be influenced by stress-induced damage, which can be assessed by examining the morphology of ER dynamics and, more locally, ER properties such as hydrophobicity, viscosity, and polarity. Although numerous ER-specific chemical probes have been developed to monitor the ER's physical and chemical parameters, the quantitative detection and super-resolution imaging of its local hydrophobicity have yet to be explored. Here, we describe a photostable ER-targeted probe with high signal-to-noise ratio for super-resolution imaging that can specifically respond to changes in ER hydrophobicity under stress based on a "reserve-release" mechanism. The probe shows an excellent ability to target ER over commercial ER dyes and can be used to track local changes of hydrophobicity by fluorescence intensity and morphology during the selective autophagy of ER (i.e., reticulophagy). By correlating the level and location of ER damage with the distribution of fluorescence intensity, we were able to assess reticulophagy at the subcellular level. Beyond that, we developed a topological analytical tool adaptable to any ER probe for detecting structural changes in ER and thus quantitatively identifying reticulophagy. The algorithm-assisted tool can also be adapted to a wide range of molecular probes and organelles. Altogether, the new probe and analytical strategy described here show promise for the quantitative detection and analysis of subtle ER damage and stress.