Synthesis of Tough and Fluorescent Self-Healing Elastomers by Scandium-Catalyzed Terpolymerization of Pyrenylethenylstyrene, Ethylene, and Anisylpropylene.

The synthesis of fluorescent self-healing polymers by the incorporation of a fluorophore-containing olefin into a polyolefin backbone through catalyst-controlled multicomponent copolymerization is of fundamental interest and practical importance, but such an approach has remained unexplored to date. Herein, we report for the first time the synthesis of tough and fluorescent self-healing polymers by sequence-controlled terpolymerization of 4-[2-(1-pyrenyl)ethenyl]styrene (Pyr), ethylene (E), and anisylpropylene (AP) using a sterically demanding half-sandwich scandium catalyst. The resulting terpolymers consisted of relatively long alternating E-alt-AP sequences, isolated Pyr units, and short E-E blocks, which exhibited excellent tensile strength, remarkable self-healability, and high fluorescence quantum yield. The excellent mechanical and self-healing properties could be attributed to the nanophase separation of the crystalline E-E segments and the hard Pyr aggregates from a flexible E-alt-AP segment matrix, in which the Pyr units not only served as an efficient fluorophore but also played an important role in forming nanodomains and enhancing the polymer mobility. Furthermore, the styrenyl C═C bond of the Pyr unit in the terpolymers could undergo [2 + 2] cycloaddition under photoirradiation, which thus enabled the fabrication of a self-healable fluorescent two-dimensional image on a terpolymer film through photolithography. This work offers an unprecedented efficient protocol for the synthesis of a brand-new family of fluorescent self-healing materials, showcasing the high potential of catalyst-controlled sequence-regular copolymerization of different olefins for the creation of novel functional polymers.

Strategies for Reducing Toxicity and Enhancing Efficacy of Chimeric Antigen Receptor T Cell Therapy in Hematological Malignancies.

Chimeric antigen receptor T cell (CAR-T) therapy in hematologic malignancies has made great progress, but there are still some problems. First, T cells from tumor patients show an exhaustion phenotype; thus, the persistence and function of the CAR-Ts are poor, and achieving a satisfactory curative effect is difficult. Second, some patients initially respond well but quickly develop antigen-negative tumor recurrence. Thirdly, CAR-T treatment is not effective in some patients and is accompanied by severe side effects, such as cytokine release syndrome (CRS) and neurotoxicity. The solution to these problems is to reduce the toxicity and enhance the efficacy of CAR-T therapy. In this paper, we describe various strategies for reducing the toxicity and enhancing the efficacy of CAR-T therapy in hematological malignancies. In the first section, strategies for modifying CAR-Ts using gene-editing technologies or combining them with other anti-tumor drugs to enhance the efficacy of CAR-T therapy are introduced. The second section describes some methods in which the design and construction of CAR-Ts differ from the conventional process. The aim of these methods is to enhance the anti-tumor activity of CAR-Ts and prevent tumor recurrence. The third section describes modifying the CAR structure or installing safety switches to radically reduce CAR-T toxicity or regulating inflammatory cytokines to control the symptoms of CAR-T-associated toxicity. Together, the knowledge summarized herein will aid in designing better-suited and safer CAR-T treatment strategies.

A Photoisomerizable Zinc (II) Complex Inhibits Microtubule Polymerization for Photoactive Therapy.

The photoisomerization-induced cytotoxicity in photopharmacology provides a unique pathway for phototherapy because it is independent of endogenous oxygen. In this study, we developed a biosafe photoisomerizable zinc(II) complex (Zn1), which releases its trans ligand (trans-L1) after being irradiated with blue light. This causes the complex to undergo photoisomerization and produce the toxic cis product (cis-L1) and generate singlet oxygen (1 O2 ). The resulting series of events caused impressive phototoxicity in hypoxic A431 skin cancer cells, as well as in a tumor model in vivo. Interestingly, Zn1 was able to inhibit tumor microtubule polymerization, while still showing good biocompatibility and biosafety in vivo. This photoisomerizable zinc(II) complex provides a novel strategy for addressing the oxygen-dependent limitation of traditional photodynamic therapy.

Making Polyisoprene Self-Healable through Microstructure Regulation by Rare-Earth Catalysts.

The creation of self-healing polymers from commodity olefins is of great interest and importance but has remained a challenge to date. We report here for the first time the synthesis of self-healing polymers by catalyst-controlled polymerization of a simple commodity diene, isoprene. We found that polyisoprenes having an appropriate mixture (ca. 70/30) of 3,4- and cis-1,4-microstructures synthesized by using a half-sandwich scandium catalyst could act as excellent self-healing elastomers without any external intervention. The unprecedented self-healability could be ascribed to nanoscale heterogeneities formed by microphase separation of the relatively hard 3,4-segments from a flexible cis-1,4-segment matrix. The hydrogenated polyisoprenes (without C=C bonds) with the analogous microstructures also exhibited excellent mechanical and self-healing properties, further demonstrating that even simple polyolefins can be made self-healable if the microstructures are appropriately regulated.

Terpolymerization of Ethylene and Two Different Methoxyaryl-Substituted Propylenes by Scandium Catalyst Makes Tough and Fast Self-Healing Elastomers.

The terpolymerization of a non-polar olefin (such as ethylene) and two different polar functional olefins in a controlled fashion is of great interest and importance but has hardly been explored to date. We report for the first time the terpolymerization of ethylene (E) and two different methoxyaryl-substituted propylenes (AR1 P=hexylanisyl propylene; AR2 P=methoxynaphthyl propylene or methoxypyrenyl propylene) by a half-sandwich scandium catalyst. The terpolymerization took place in a sequence-controlled fashion, affording unique multi-block copolymers composed of two different ethylene-alt-methoxyarylpropylene sequences E-alt-AR1 P (soft segments) and E-alt-AR2 P (hard segments) and relatively short ethylene-ethylene (EE) blocks (crystalline segments). The terpolymers exhibited excellent elasticity and unprecedented self-healing as a result of microphase separation of nanodomains of the crystalline EE segments and the hard amorphous E-alt-AR2 P segments from a very flexible E-alt-AR1 P matrix, demonstrating unique synergy of the three different components.

Co-syndiospecific Alternating Copolymerization of Functionalized Propylenes and Styrene by Rare-Earth Catalysts.

The precise control of monomer sequence and stereochemistry in copolymerization is of much interest and importance for the synthesis of functional polymers, but studies toward this goal have met with only limited success to date. Now, the co-syndiospecific alternating copolymerization of methoxyphenyl- and N,N-dimethylaminophenyl-functionalized propylenes with styrene by half-sandwich rare-earth catalysts is reported. This reaction efficiently afforded the corresponding functionalized propylene-alt-styrene copolymers with a perfect alternating sequence and excellent co-syndiotacticity (rrrr >99 %), thus constituting the first example of co-stereospecific alternating copolymerization of polar and non-polar olefins.

Synthesis of Self-Healing Polymers by Scandium-Catalyzed Copolymerization of Ethylene and Anisylpropylenes.

Self-healing materials are of fundamental interest and practical importance. Herein we report the synthesis of a new class of self-healing materials, formed by the copolymerization of ethylene and anisyl-substituted propylenes using a sterically demanding half-sandwich scandium catalyst. The copolymerization proceeded in a controlled fashion, affording unique multi-block copolymers composed of relatively long alternating ethylene- alt-anisylpropylene sequences and short ethylene-ethylene units. By controlling the molecular weight and varying the anisyl substituents, a series of copolymers that show a wide range of glass-transition temperatures ( Tg) and mechanical properties have been obtained. The copolymers with Tg below room temperature showed high elastic modulus, high toughness, and remarkable self-healability, being able to autonomously self-heal upon mechanical damage not only in a dry environment but also in water and aqueous acid and alkaline solutions, while those with Tg around or above room temperature exhibited excellent shape-memory property. The unique mechanical properties may be ascribed to the phase separation of the crystalline ethylene-ethylene nanodomains from the ethylene- alt-anisylpropylene matrix.

Scandium-Catalyzed Regio- and Stereoselective Cyclopolymerization of Functionalized α,ω-Dienes and Copolymerization with Ethylene.

The precise control of regio- and stereochemistry in the cyclopolymerization of heteroatom-functionalized α,ω-dienes is of much interest and importance, but has remained a challenge to date. We report herein the regio-, diastereoselective and stereoregular cyclopolymerization of ether- and thioether-functionalized 1,6-heptadienes by a half-sandwich scandium catalyst. The polymerization of 4-benzyloxy-1,6-heptadiene selectively afforded the corresponding benzyloxy-functionalized cyclic polymer composed of 1,2,4-cis-substituted-ethylenecyclopentane (ECP) microstructures in a isospecific fashion (95% mmm). In contrast, the polymerization of 4-phenylthio-1,6-heptadiene exclusively yielded 1,2-trans-1,4-cis-ECP units with high isotacticity (95% rrr). The DFT calculations revealed that an interaction between the scandium atom in the catalyst and the heteroatom in a diene monomer played an important role in controlling the regio- and stereochemistry of the diene cyclopolymerization. The copolymerization of functionalized 1,6-heptadienes with ethylene has also been achieved in a controlled fashion.

Exploring Steric Effects in Diastereoselective Synthesis of Chiral Aminophenolate Zinc Complexes and Stereoselective Ring-Opening Polymerization of rac-Lactide.

A series of tridentate chiral aminophenol proligands and corresponding zinc complexes, LZnX (L = (S)-2-{[(1-R(4)-2-pyrrolidinyl)CH2N(R(3))-]CH2}-6-R(1)-4-R(2)-C6H2O, X = N(SiMe3)2, R(3) = (n)Bu, R(4) = Bn: R(1) = R(2) = Cl (1), R(1) = R(2) = Me (2), R(1) = R(2) = (t)Bu (3); X = N(SiMe3)2, R(1) = trityl, R(2) = Me: R(3) = n-octyl, R(4) = Bn (4), R(3) = Bn, R(4) = Bn (5), R(3) = (n)Bu, R(4) = naphthalen-1-ylmethyl (6), R(3) = (n)Bu, R(4) = (i)Pr (7); R(1) = R(2) = cumyl, R(3) = Et, R(4) = Bn: X = N(SiMe3)2 (8), X = O(t)Bu (9), X = Et (10), X = Cl (11)), have been synthesized. Complexes 4, 6, and 11 were obtained as enantiopure products (4 and 6 as enantiopure a; 11 as enantiopure b), while complexes 1-3, 5, and 7-10 as a pair of diastereomers, but in different ratios, which have been proved by X-ray diffraction and NMR spectroscopic studies. When exposed to the ring-opening polymerization of rac-lactide, most of these complexes can effectively produce PLAs with narrow polydispersities, desirable molecular weights, and moderate to high isotacticities. The structure-selectivity relationships, including the relationships of structure-synthesis diastereoselectivity and structure-polymerization stereoselectivity, have been further investigated. Consistent trends of diastereoselectivity and stereoselectivity are observed with the variations of the R(1) group at the ortho-position of the phenolate ring and the R(3) group in the pyrrolidinyl moiety. The decrease of the steric bulkiness of the R(4) group on the central amine has less influence on the diastereoselectivity, but leads to considerable loss of the stereoselectivity, whereas the decrease of the steric bulkiness of the X group results in a reverse of the diastereoselectivity, but shows no influence on the stereoselectivity. There is probably no direct relationship between the diastereoselectivity in complex synthesis and the stereoselectivity of the complex toward the ROP of rac-LA. The stereocontrol of these complexes might largely rely on the substituents in the ligand framework rather than their diastereomer ratios.

Stereoselective Polymerization of rac-Lactide Catalyzed by Zinc Complexes with Tetradentate Aminophenolate Ligands in Different Coordination Patterns: Kinetics and Mechanism.

A series of monomeric zinc silylamido complexes bearing [NNNO]-type tetradentate aminophenolate ligands, LZnN(SiMe3)2 [L = {(2-R(1))ArCH2N[(CH2)2R(2)]CH2(4-R(4)-6-R(3))C6H2O-}, R(1) = NMe2, R(2) = N(i)Pr2, R(3) = R(4) = Cl (1), R(3) = R(4) = cumyl (3); R(1) = NMe2, R(2) = NEt2, R(3) = R(4) = cumyl (2), R(3) = CPh3, R(4) = Me (4); R(1) = NEt2, R(2) = NEt2, R(3) = CPh3, R(4) = Me (5); R(1) = NMe2, R(2) = (S)-1-butylpyrrolidin-2-yl, R(3) = R(4) = cumyl (6), R(3) = CPh3, R(4) = Me (7)], have been synthesized via reactions of Zn[N(SiMe3)2]2 and 1 equiv of the corresponding aminophenols. The monomeric nature and versatile coordination patterns of these complexes in the solid state were further confirmed by X-ray diffraction studies on complexes 2, 3, 5, and 7. In complex 3, the N,N-diisopropylamino group on the pendant side arm does not coordinate to the metal center; only the remaining three donors of the aminophenolate ligand and the silylamido group interact with the zinc center. By contrast, in complexes 2, 5, and 7, the amino group of the aryl moiety does not coordinate to the metal center, while the amino group on the pendant side arm coordinates. At room temperature, the above-mentioned structural features of these complexes are retained in solution, as confirmed by (1)H NMR spectroscopy. Complexes 1-7 proved to be efficient initiators for the ring-opening polymerization of rac-lactide (rac-LA) at ambient temperature, and the polymerizations were better controlled in the presence of 2-propanol. The coordination pattern of the aminophenolate ligand exerted a significant influence on the stereoselectivity of the corresponding complex toward the polymerization of rac-LA, leading to the production of heterotactic biased polylactides (PLAs) by complexes 1 and 3 (Pm = 0.40-0.46) and moderately to highly isotactic PLAs by complexes 2 and 4-7 (Pm = 0.70-0.81). Detailed kinetic investigations revealed a first-order dependence on the monomer concentration for all complexes and different orders in the initiator concentration ranging from 1.78 to 1.81. The nature of the solvent as well as the molar ratio of the zinc complex and 2-propanol also displayed certain influence on the order of rac-LA polymerization in the initiator concentration. Factional orders of 1.80, 1.38, and 1.11 were obtained by using complex 5/(i)PrOH (1:1) in toluene and tetrahydrofuran and complex 5/(i)PrOH (1:2) in toluene, respectively. On the basis of DOSY and (1)H and (13)C NMR studies of zinc alkoxide model complexes "LZn(OCMe2COOMe)" as well as the fractional orders of 1.78-1.81 in the initiator concentration, activation/insertion processes likely involving more than one monomeric active species were then hypothesized.

Self-Assembly of Erlotinib-Platinum(II) Complexes for Epidermal Growth Factor Receptor-Targeted Photodynamic Therapy.

Due to cell mutation and self-adaptation, the application of clinical drugs with early epidermal growth factor receptor (EGFR)-targeted inhibitors is severely limited. To overcome this limitation, herein, the synthesis and in-depth biological evaluation of an erlotinib-platinum(II) complex as an EGFR-targeted anticancer agent is reported. The metal complex is able to self-assemble inside an aqueous solution and readily form nanostructures with strong photophysical properties. While being poorly toxic toward healthy cells and upon treatment in the dark, the compound was able to induce a cytotoxic effect in the very low micromolar range upon irradiation against EGFR overexpressing (drug resistant) human lung cancer cells as well as multicellular tumor spheroids. Mechanistic insights revealed that the compound was able to selectively degrade the EGFR using the lysosomal degradation pathway upon generation of singlet oxygen at the EGFR. We are confident that this work will open new avenues for the treatment of EGFR-overexpressing tumors.

Facile synthesis of a hydrazone-based zinc(ii) complex for ferroptosis-augmented sonodynamic therapy.

Sonodynamic therapy (SDT), as a novel non-invasive cancer treatment modality derived from photodynamic therapy (PDT), has drawn much attention due to its unique advantages for the treatment of deep tumors. Zinc-based complexes have shown great clinical prospect in PDT due to their excellent photodynamic activity and biosafety. However, their application in SDT has lagged seriously behind. Exploring efficient zinc-based complexes as sono-sensitizers remains an appealing but significantly challenging task. Herein, we develop a hydrazone ligand-based zinc complex (ZnAMTC) for SDT of tumors in vitro and in vivo. ZnAMTC was facilely synthesized via a two-step reaction from low-cost raw materials without tedious purification. It shows negligible dark toxicity and can produce singlet oxygen (1O2) under ultrasound (US) irradiation, exhibiting high sono-cytotoxicity to various cancer cells. Mechanism studies show that ZnAMTC can effectively reduce the levels of glutathione (GSH) and glutathione peroxidase 4 (GPX4) under US irradiation and later cause ferroptosis of cancer cells. In vivo studies further demonstrate that ZnAMTC exhibits efficient tumor growth inhibition under US irradiation and has good biosafety. This work provides useful insights into the design of first-row transition metal complexes for SDT application.

An Electron Donor-Acceptor Structured Rhenium(I) Complex Photo-Sensitizer Evokes Mutually Reinforcing "Closed-Loop" Ferroptosis and Immunotherapy.

The hypoxic microenvironment of solid tumors severely lowers the efficacy of oxygen-dependent photodynamic therapy (PDT). The development of hypoxia-tolerant photosensitizers for PDT is an urgent requirement. In this study, a novel rhenium complex (Re-TTPY) to develop a "closed-loop" therapy based on PDT-induced ferroptosis and immune therapy is reported. Due to its electron donor-acceptor (D-A) structure, Re-TTPY undergoes energy transfer and electron transfer processes under 550 nm light irradiation and displays hypoxia-tolerant type I/II combined PDT capability, which can generate 1O2, O2 -, and ·OH simultaneously. Further, the reactive oxygen species (ROSs) leads to the depletion of 1,4-dihydronicotinamide adenine dinucleotide (NADH), glutathione peroxidase 4 (GPX4), and glutathione (GSH). As a result, ferroptosis occurs in cells, simultaneously triggers immunogenic cell death (ICD), and promotes the maturation of dendritic cells (DCs) and infiltration of T cells. The release of interferon-γ (IFN-γ) by CD8+ T cells downregulates the expression of GPX4, further enhancing the occurrence of ferroptosis, and thereby, forming a mutually reinforcing "closed-loop" therapeutic approach.

Enhanced Sonodynamic Therapy for Deep Tumors Using a Self-Assembled Organoplatinum(II) Sonosensitizer.

Despite the promising advances in photodynamic therapy (PDT), it remains challenging to target and treat deep-seated solid tumors effectively. Herein, we developed an organoplatinum(II) complex (Pt-TPE) with self-assembly properties for sonodynamic therapy (SDT). Pt-TPE forms a nanofiber network structure through Pt-Pt and π-π stacking interactions. Notably, under ultrasound (US), Pt-TPE demonstrates unique self-assembly-induced singlet oxygen (1O2) generation due to a significantly enhanced singlet-triplet intersystem crossing (ISC). This generation of 1O2 occurs exclusively in the self-assembled state of Pt-TPE. Additionally, Pt-TPE exhibits sono-cytotoxicity against cancer cells by impairing mitochondrial membrane potential (MMP), inhibiting glucose uptake, and aerobic glycolysis. Furthermore, US-activated Pt-TPE significantly inhibits deep solid tumors in mice, achieving remarkable therapeutic efficacy even at penetration depths greater than 10 cm. This study highlights the potential of self-assembled metal complexes to enhance the efficacy of SDT for treating deep tumors.

Large-scale annotated dataset for cochlear hair cell detection and classification.

Our sense of hearing is mediated by cochlear hair cells, of which there are two types organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains 5-15 thousand terminally differentiated hair cells, and their survival is essential for hearing as they do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. Machine learning can be used to automate the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, rat, guinea pig, pig, primate, and human cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 107,000 hair cells which have been identified and annotated as either inner or outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair-cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to give other hearing research groups the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.

Photoacidolysis-Mediated Iridium(III) Complex for Photoactive Antibacterial Therapy.

Photoactive antibacterial therapy is one of the novel therapeutic methods that has great application potential and prospects for curbing bacterial infections. In this work, a photoactivated iridium complex (Ir-Cl) is synthesized for photoactive antibacterial research. Ir-Cl exhibits photoacidolysis, which can generate H+ and be converted into a photolysis product Ir-OH under blue light irradiation. At the meantime, this process is accompanied by 1O2 generation. Notably, Ir-Cl can selectively permeate S. aureus and exhibit excellent photoactive antibacterial activity. Mechanism studies show that Ir-Cl can ablate bacterial membranes and biofilms under light irradiation. Metabolomics analysis proves that Ir-Cl with light exposure mainly disturbs some amino acids' degradation (e.g., valine, leucine, isoleucine, arginine) and pyrimidine metabolism, which indirectly causes the ablation of biofilms and ultimately produces irreversible damage to S. aureus. This work provides guidance for metal complexes in antibacterial application.

Combined Model of OCT Angiography and Structural OCT Parameters to Predict Paracentral Visual Field Loss in Primary Open-Angle Glaucoma.

PURPOSE: To assess a model combining OCT angiography (OCTA) and OCT parameters to predict the severity of paracentral visual field (VF) loss in primary open-angle glaucoma (POAG). DESIGN: Cross-sectional study. PARTICIPANTS: Forty-four patients with POAG and 42 control subjects underwent OCTA and OCT imaging with a swept-source OCT device. METHODS: The circumpapillary microvasculature was quantified for vessel density (cpVD) and flow (cpFlow) after delineation of Bruch's membrane opening and removal of large vessels. Retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured from structural OCT. Paracentral total deviation (PaTD) was defined as the average of the total deviation values within the central 10 degrees on Humphrey VF testing (24-2) for upper and lower hemifields. The OCT and OCTA parameters were measured in the affected hemisphere corresponding to the hemifield with lower PaTD for POAG patients. Models were created to predict affected PaTD based on RNFLT alone; RNFLT and BMO-MRW; OCTA alone; or RNFLT, BMO-MRW and OCTA parameters. The models were compared using coefficient of determination (r2) and Bayesian information criterion (BIC) score. Bayesian information criterion decrease of ≥6 indicates strong evidence for model improvement. MAIN OUTCOME MEASURES: Performance of models containing OCT and OCTA parameters in predicting PaTD. RESULTS: Patients with POAG and controls were similar in age and sex (65.9 ± 9.5 years and 38.4% male overall, P ≥ 0.56 for both). Average RNFLT, minimum RNFLT, average BMO-MRW, minimum BMO-MRW, cpVD, and cpFlow were all significantly lower (all P < 0.001) in the affected hemisphere in patients with POAG than in controls. In patients with POAG, the average mean deviation was -4.33 ± 3.25 dB; the PaTD of the affected hemifield averaged -4.55 ± 5.26 dB and correlated significantly with both OCTA and structural OCT parameters (r ≥ 0.43, P ≤ 0.004 for all). The model containing RNFLT, BMO-MRW, and OCTA parameters was superior in predicting affected PaTD (r2 = 0.47, BIC = 290.7), with higher r2 and lower BIC compared with all 3 other models. CONCLUSIONS: A combined model of OCTA and structural OCT parameters can predict the severity of paracentral VF loss of the affected hemifield, supporting clinical utility of OCTA in patients with POAG with paracentral VF loss. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Demethylating therapy increases cytotoxicity of CD44v6 CAR-T cells against acute myeloid leukemia.

Background: CD44v6 chimeric antigen receptor T (CD44v6 CAR-T) cells demonstrate strong anti-tumor ability and safety in acute myeloid leukemia (AML). However, the expression of CD44v6 on T cells leads to transient fratricide and exhaustion of CD44v6 CAR-T cells, which affect the application of CD44v6 CAR-T. The exhaustion and function of T cells and CD44v6 expression of AML cells are associated with DNA methylation. Hypomethylating agents (HAMs) decitabine (Dec) and azacitidine (Aza) have been widely used to treat AML. Therefore, there may be synergy between CD44v6 CAR-T cells and HAMs in the treatment of AML. Methods: CD44v6 CAR-T cells pretreated with Dec or Aza were co-cultured with CD44v6+ AML cells. Dec or aza pretreated AML cells were co-cultured with CD44v6 CAR-T cells. The cytotoxicity, exhaustion, differentiation and transduction efficiency of CAR-T cells, and CD44v6 expression and apoptosis in AML cells were detected by flow cytometry. The subcutaneous tumor models were used to evaluate the anti-tumor effect of CD44v6 CAR-T cells combined with Dec in vivo. The effects of Dec or Aza on gene expression profile of CD44v6 CAR-T cells were analyzed by RNA-seq. Results: Our results revealed that Dec and Aza improved the function of CD44v6 CAR-T cells through increasing the absolute output of CAR+ cells and persistence, promoting activation and memory phenotype of CD44v6 CAR-T cells, and Dec had a more pronounced effect. Dec and Aza promoted the apoptosis of AML cells, particularly with DNA methyltransferase 3A (DNMT3A) mutation. Dec and Aza also enhanced the CD44v6 CAR-T response to AML by upregulating CD44v6 expression of AML cells regardless of FMS-like tyrosine kinase 3 (FLT3) or DNMT3A mutations. The combination of Dec or Aza pretreated CD44v6 CAR-T with pretreated AML cells demonstrated the most potent anti-tumor ability against AML. Conclusion: Dec or Aza in combination with CD44v6 CAR-T cells is a promising combination therapy for AML patients.

Opposing gradients of ribbon size and AMPA receptor expression underlie sensitivity differences among cochlear-nerve/hair-cell synapses.

The auditory system transduces sound-evoked vibrations over a range of input sound pressure levels spanning six orders of magnitude. An important component of the system mediating this impressive dynamic range is established in the cochlear sensory epithelium, where functional subtypes of cochlear nerve fibers differ in threshold sensitivity, and spontaneous discharge rate (SR), by more than a factor of 1000 (Liberman, 1978), even though, regardless of type, each fiber contacts only a single hair cell via a single ribbon synapse. To study the mechanisms underlying this remarkable heterogeneity in threshold sensitivity among the 5-30 primary sensory fibers innervating a single inner hair cell, we quantified the sizes of presynaptic ribbons and postsynaptic AMPA receptor patches in >1200 synapses, using high-power confocal imaging of mouse cochleas immunostained for CtBP2 (C-terminal binding protein 2, a major ribbon protein) and GluR2/3 (glutamate receptors 2 and 3). We document complementary gradients, most striking in mid-cochlear regions, whereby synapses from the modiolar face and/or basal pole of the inner hair cell have larger ribbons and smaller receptor patches than synapses located in opposite regions of the cell. The AMPA receptor expression gradient likely contributes to the differences in cochlear nerve threshold and SR seen on the two sides of the hair cell in vivo (Liberman, 1982a); the differences in ribbon size may contribute to the heterogeneity of EPSC waveforms seen in vitro (Grant et al., 2010).

The Role of Exosomes in the Progression and Therapeutic Resistance of Hematological Malignancies.

Exosomes are membrane limited structures which derive from cell membranes and cytoplasm. When released into extracellular space, they circulate through the extracellular fluid, including the peripheral blood and tissue fluid. Exosomes surface molecules mediate their targeting to specific recipient cells and deliver their contents to recipient cells by receptor-ligand interaction and/or phagocytosis and/or endocytosis or direct fusion with cell membrane. Exosomes contain many functional molecules, including nucleic acids (DNAs, mRNAs, non-coding RNAs), proteins (transcription factors, enzymes), and lipids which have biological activity. By passing these cargos, exosomes can transfer information between cells. In this way, exosomes are extensively involved in physiological and pathological processes, such as angiogenesis, matrix reprogramming, coagulation, tumor progression. In recent years, researcher have found that exosomes from malignant tumors can mediate information exchange between tumor cells or between tumor cells and non-tumor cells, thereby promoting tumor survival, progression, and resistance to therapy. In this review, we discuss the pro-tumor and anti-therapeutic effects of exosomes in hematological malignancies, hoping to contribute to the early conquest of hematological malignancy.