Development of small molecule drugs targeting immune checkpoints

Immune checkpoint inhibitors(ICIs)are used to relieve and refuel anti-tumor immunity by blocking the interaction,transcription,and translation of co-inhibitory immune checkpoints or degrading co-inhibitory immune checkpoints.Thousands of small molecule drugs or biological materials,especially antibody-based ICIs,are actively being studied and antibodies are currently widely used.Limitations,such as anti-tumor efficacy,poor membrane permeability,and unneglected tolerance issues of antibody-based ICIs,remain evident but are thought to be overcome by small molecule drugs.Recent structural studies have broadened the scope of candidate immune checkpoint molecules,as well as innovative chemical inhibitors.By way of comparison,small molecule drug-based ICIs represent superior oral bioavailability and favorable pharmacokinetic features.Several ongoing clinical trials are exploring the synergetic effect of ICIs and other therapeutic strategies based on multiple ICI functions,including immune regulation,anti-angiogenesis,and cell cycle regulation.In this review we summarized the current progression of small molecule ICIs and the mechanism underlying immune checkpoint proteins,which will lay the foundation for further exploration.

H-and J-aggregation of conjugated small molecules in organic solar cells

As H-and J-aggregation receive more and more attention in the research of organic solar cells(OSCs),especially in small molecular systems,deep understanding of aggregation behavior is needed to guide the design of conjugated small molecular structure and the fabrication process of OSC device.For this end,this review is written.Here,the review firstly introduced the basic information about H-and J-aggregation of conjugated small molecules in OSCs.Then,the characteristics of H-and J-aggregation and the methods to identify them were summarized.Next,it reviewed the research progress of H-and J-aggregation of conjugated small molecules in OSCs,including the factors influencing H-and J-aggregation in thin film and the effects of H-and J-aggregation on OPV performance.

Variation of microbiological and small molecule metabolite profiles of Nuodeng ham during ripening by high-throughput sequencing and GC-TOF-MS

The internal microbial diversity and small molecular metabolites of Nuodeng ham in different processing years(the first,second and third year sample)were analyzed by high-throughput sequencing technology and gas chromatography-time of flight mass spectrography(GC-TOF-MS)to study the effects of microorganisms and small molecular metabolites on the quality of ham in different processing years.The results showed that the dominant bacteria phyla of Nuodeng ham in different processing years were Proteobacteria and Firmicutes,the dominant fungi phyla were Ascomycota and Basidiomycota,while Staphylococcus and Aspergillus were the dominant bacteria and fungi of Nuodeng ham,respectively.Totally,252 kinds of small molecular metabolites were identified from Nuodeng ham in different processing years,and 12 different metabolites were screened through multivariate statistical analysis.Further metabolic pathway analysis showed that 23 metabolic pathways were related to ham fermentation,of which 8 metabolic pathways had significant effects on ham fermentation(Impact>0.01,P<0.05).The content of L-proline,phenyllactic acid,L-lysine,carnosine,taurine,D-proline,betaine and creatine were significantly positively correlated with the relative abundance of Staphylococcus and Serratia,but negatively correlated with the relative abundance of Halomonas,Aspergillus and Yamadazyma.

Chlorine-Substituent Regulation in Dopant-Free Small-Molecule Hole-Transport Materials Improves the Effi ciency and Stability of Inverted Perovskite Solar Cells

Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.

Small molecule inhibitor DDQ-treated hippocampal neuronal cells show improved neurite outgrowth and synaptic branching

The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.

Neural progenitor cells derived from fibroblasts induced by small molecule compounds under hypoxia for treatment of Parkinson’s disease in rats

Neural progenitor cells(NPCs) capable of self-renewal and differentiation into neural cell lineages offer broad prospects for cell therapy for neurodegenerative diseases. However, cell therapy based on NPC transplantation is limited by the inability to acquire sufficient quantities of NPCs. Previous studies have found that a chemical cocktail of valproic acid, CHIR99021, and Repsox(VCR) promotes mouse fibroblasts to differentiate into NPCs under hypoxic conditions. Therefore, we used VCR(0.5 mM valproic acid, 3 μM CHIR99021, and 1 μM Repsox) to induce the reprogramming of rat embryonic fibroblasts into NPCs under a hypoxic condition(5%). These NPCs exhibited typical neurosphere-like structures that can express NPC markers, such as Nestin, SRY-box transcription factor 2, and paired box 6(Pax6), and could also differentiate into multiple types of functional neurons and astrocytes in vitro. They had similar gene expression profiles to those of rat brain-derived neural stem cells. Subsequently, the chemically-induced NPCs(ciNPCs) were stereotactically transplanted into the substantia nigra of 6-hydroxydopamine-lesioned parkinsonian rats. We found that the ciNPCs exhibited long-term survival, migrated long distances, and differentiated into multiple types of functional neurons and glial cells in vivo. Moreover, the parkinsonian behavioral defects of the parkinsonian model rats grafted with ciNPCs showed remarkable functional recovery. These findings suggest that rat fibroblasts can be directly transformed into NPCs using a chemical cocktail of VCR without introducing exogenous factors, which may be an attractive donor material for transplantation therapy for Parkinson’s disease.

Precision medicine in inflammatory bowel disease:Individualizing the use of biologics and small molecule therapies

The advent of biologics and small molecules in inflammatory bowel disease(IBD)has marked a significant turning point in the prognosis of IBD,decreasing the rates of corticosteroid dependence,hospitalizations and improving overall quality of life.The introduction of biosimilars has also increased affordability and enhanced access to these otherwise costly targeted therapies.Biologics do not yet represent a complete panacea:A subset of patients do not respond to first-line anti-tumor necrosis factor(TNF)-alpha agents or may subsequently demonstrate a secondary loss of response.Patients who fail to respond to anti-TNF agents typically have a poorer response rate to second-line biologics.It is uncertain which patient would benefit from a different sequencing of biologics or even a combination of biologic agents.The introduction of newer classes of biologics and small molecules may provide alternative therapeutic targets for patients with refractory disease.This review examines the therapeutic ceiling in current treatment strategies of IBD and the potential paradigm shifts in the future.

Variaiton in the composition of small molecule compounds in the egg yolks of Asian Short-toed Larks between early and late broods

The egg yolks of birds contain most of the maternally derived materials required for embryo development and are an important factor influencing embryo development and offspring viability.Individual variation in egg-laying date frequently occurs in passerines inhabiting highly seasonal environments.Females laying in early and late stages of the breeding season encounter different environment temperatures and food conditions,which can affect the levels of metabolities in their bodies,thereby altering the transmission of these materials to the eggs.We test a hypothesis that yolk small molecule compounds of Asian Short-toed Lark(Alaudala cheleensis)could vary between early(mid-May)and late(mid-June)broods.Using the UHPLC-MS/MS method,683 compounds belonging to 21 compound groups are detected in the yolks.The contents of 18 compounds are significantly different between early and late broods.Ten differential compounds are significantly higher in the early laid eggs,among whichγ-aminobutyric acid,creatine,prostaglandins,palmitoleic acid,linoleic acid,and trans linoleic acid are related to low environment temperature response.The eggs laid in late stage exhibit significantly higher levels of 5-L-glutamyl-L-alanine andγ-glutamate-leucine,1,3-dimethyluric acid and mannose,which may be attributed to females in the late group consuming more insects.We suggest conducting a comprehensive investigation to reveal the yolk small molecule compounds mediated maternal effects on offspring phenotypes under varying ecological conditions.

Investigation on small molecule-aptamer dissociation equilibria based on antisense displacement probe

Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety.

Therapies for Tau-associated neurodegenerative disorders:targeting molecules,synapses,and cells

Advances in experimental and computational technologies continue to grow rapidly to provide novel avenues for the treatment of neurodegenerative disorders. Despite this, there remain only a handful of drugs that have shown success in late-stage clinical trials for Tau-associated neurodegenerative disorders. The most commonly prescribed treatments are symptomatic treatments such as cholinesterase inhibitors and N-methyl-D-aspartate receptor blockers that were approved for use in Alzheimer's disease. As diagnostic screening can detect disorders at earlier time points, the field needs pre-symptomatic treatments that can prevent, or significantly delay the progression of these disorders(Koychev et al., 2019). These approaches may be different from late-stage treatments that may help to ameliorate symptoms and slow progression once symptoms have become more advanced should early diagnostic screening fail. This mini-review will highlight five key avenues of academic and industrial research for identifying therapeutic strategies to treat Tau-associated neurodegenerative disorders. These avenues include investigating(1) the broad class of chemicals termed “small molecules”;(2) adaptive immunity through both passive and active antibody treatments;(3) innate immunity with an emphasis on microglial modulation;(4) synaptic compartments with the view that Tau-associated neurodegenerative disorders are synaptopathies. Although this mini-review will focus on Alzheimer's disease due to its prevalence, it will also argue the need to target other tauopathies, as through understanding Alzheimer's disease as a Tau-associated neurodegenerative disorder, we may be able to generalize treatment options. For this reason, added detail linking back specifically to Tau protein as a direct therapeutic target will be added to each topic.

Kinetic and thermodynamic synergy of organic small molecular additives enables constructed stable zinc anode

An organic small molecule additive zinc formate is introduced to construct stable Zn metal interphase by electrochemical kinetic control and thermodynamic adjustment.It partially forms a water-formate concomitant dipole layer at the internal Helmholtz electrical double layers(HEDLs) under the preferential adsorption function of formate on Zn surface,reducing the occurrence of side reactions at phase interface.Meanwhile,free formate in HEDLs regulates the Zn^(2+) solvation sheath structure to accelerate the desolvation,transference,and deposition kinetics of Zn^(2+).Besides,the hydrolysis reaction of zinc formate increases the hydrogen evolution overpotential,inhibiting the thermodynamic tendency of hydrogen evolution.Consequently,it presents stable cycle for more than 2400 h at 5 mA cm^(-2),as well as an average Coulombic efficiency of 99.8% at 1 A g^(-1) after 800 cycles in the Zn‖VO_(2) full cell.The interphase engineering strategy zinc anode by organic small molecular brings new possibility towards high-performance aqueous zinc-ion batteries.

Recent Progress of Surface Passivation Molecules for Perovskite Solar Cell Applications

Due to the solution processable nature,the prepared perovskite films are polycrystalline with considerable number of defects.These defects,especially defects at interface accelerate the carrier recombination and reduce the carrier collection.Besides,the surface defects also affect the long-term stability of the perovskite solar cells(PVSCs).To solve this problem,surface passivation molecules are introduced at selective interface(the interface between perovskite and carrier selective layer).This review summarizes recent progress of small molecules used in PVSCs.Firstly,different types of defect states in perovskite films are introduced and their effects on device performance are discussed.Subsequently,surface passivation molecules are divided into four categories,and the interaction between the functional groups of the surface passivation molecules and selective defect states in perovskite films are highlighted.Finally,we look into the prospects and challenges in design noble small molecules for PVSCs applications.

Advancements in the preparation of high-performance liquid chromatographic organic polymer monoliths for the separation of small-molecule drugs

The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.

Positioning of old and new biologicals and small molecules in the treatment of inflammatory bowel diseases

The past decade has brought substantial advances in the management of inflammatory bowel diseases(IBD). The introduction of tumor necrosis factor(TNF) antagonists, evidence for the value of combination therapy, the recog-nition of targeting lymphocyte trafficking and activation as a viable treatment, and the need for early treatment of high-risk patients are all fundamental concepts for current modern IBD treatment algorithms. In this article, authors review the existing data on approved biologicals and small molecules as well as provide insight on the current positioning of approved therapies. Patient stratification for the selection of specific therapies, therapeutic targets and patient monitoring will be discussed as well. The thera-peutic armamentarium for IBD is expanding as novel and more targeted therapies become available. In the absence of comparative trials, positioning these agents is becoming difficult. Emerging concepts for the future will include an emphasis on the development of algorithms which will facilitate a greater understanding of the positioning of novel biological drugs and small molecules in order to best tailor therapy to the patient. In the interim, anti-TNF therapy remains an important component of IBD therapy with the most real-life evidence and should be considered as first-line therapy in patients with complicated Crohn's disease and in acute-severe ulcerative colitis. The safety and efficacy of these ‘older' anti-TNF therapies can be optimized by adhering to therapeutic algorithms which combine clinical and objective markers of disease severityand response to therapy.

Small molecules for mesenchymal stem cell fate determination

Mesenchymal stem cells(MSCs)are adult stem cells harboring self-renewal and multilineage differentiation potential that are capable of differentiating into osteoblasts,adipocytes,or chondrocytes in vitro,and regulating the bone marrow microenvironment and adipose tissue remodeling in vivo.The process of fate determination is initiated by signaling molecules that drive MSCs into a specific lineage.Impairment of MSC fate determination leads to different bone and adipose tissue-related diseases,including aging,osteoporosis,and insulin resistance.Much progress has been made in recent years in discovering small molecules and their underlying mechanisms control the cell fate of MSCs both in vitro and in vivo.In this review,we summarize recent findings in applying small molecules to the trilineage commitment of MSCs,for instance,genistein,medicarpin,and icariin for the osteogenic cell fate commitment;isorhamnetin,risedronate,and arctigenin for pro-adipogenesis;and atractylenolides and dihydroartemisinin for chondrogenic fate determination.We highlight the underlying mechanisms,including direct regulation,epigenetic modification,and post-translational modification of signaling molecules in the AMPK,MAPK,Notch,PI3K/AKT,Hedgehog signaling pathways etc.and discuss the small molecules that are currently being studied in clinical trials.The target-based manipulation of lineage-specific commitment by small molecules offers substantial insights into bone marrow microenvironment regulation,adipose tissue homeostasis,and therapeutic strategies for MSC-related diseases.

Photodetectors based on small-molecule organic semiconductor crystals

Small-molecule organic semiconductor crystals(SMOSCs) combine broadband light absorption(ultraviolet–visible–near infrared) with long exciton diffusion length and high charge carrier mobility. Therefore, they are promising candidates for realizing high-performance photodetectors. Here, after a brief resume of photodetector performance parameters and operation mechanisms, we review the recent advancements in application of SMOSCs as photodetectors, including photoconductors, phototransistors, and photodiodes. More importantly, the SMOSC-based photodetectors are further categorized according to their detection regions that cover a wide range from ultraviolet to near infrared. Finally, challenges and outlooks of SMOSC-based photodetectors are provided.

Protein kinase small molecule inhibitors for rheumatoid arthritis: Medicinal chemistry/clinical perspectives

Medicinal chemistry strategies have contributed to the development, experimental study of and clinical trials assessment of the first type of protein kinase small molecule inhibitor to target the Janus kinase/Signal Transducers and Activators of Transcription(JAK/STAT) signaling pathway. The orally administered small molecule inhibitor, tofacitinib, is the first drug to target the JAK/STAT pathway for entry into the armamentarium of the medical therapy of rheumatoid arthritis. The introduction of tofacitinib into general rheumatologic practice coupled with increasing understanding that additional cellular signal transduction pathways including the mitogen-activated protein kinase and phosphatidylinositide-3-kinase/Akt/mammalian target of rapa-mycin pathways as well as spleen tyrosine kinase also contribute to immune-mediated inflammatory in rheumatoid arthritis makes it likely that further development of orally administered protein kinase small molecule inhibitors for rheumatoid arthritis will occur in the near future.

Isolation of a small molecule with anti-MRSA activity from a mangrove symbiont Streptomyces sp.PVRK-1 and its biomedical studies in Zebrafish embryos

Objective:The aim of the present study was to isolate the anti-MRSA(Methicillin Resistant Staphylococcus aureus)molecule from the Mangrove symbiont Streptomyces and its biomedical studies in Zebrafish embryos.Methods:MRSA was isolated from the pus samples of Colachal hospitals and confirmed by amplification of mecA gene.Anti-MRSA molecule producing strain was identified by!6s rRNA gene sequencing.Anti-MRSA compound production was optimized by Solid State Fermentation(SSF)and the purification of the active molecule was carried out by TLC and RP-HPLC.The inhibitory concentration and LC_(50)were calculated using Statistical software SPSS.The Biomedical studies including the cardiac assay and organ toxicity assessment were carried out in Zebraiish.Results:The bioactive anti-MRSA small molecule A,was purified by TLC with Rf value of 0.37 with 1.389 retention time at RP-HPLC.The Inhibitory Concentration of the purified molecule A_2 was 30μg/mL but,the inhibitory concentration of the MRSA in the infected embryo was 32-34μg/mL for TLC purified molecule A,with LC_(50)mean value was61.504μg/mL.Zebrafish toxicity was assessed in 48-60μg/mL by observing the physiological deformities and the heart beat rates(HBR)of embryos for anti MRSA molecule showed the mean of 41.33-41.67 HBR/15 seconds for 40μg/mL and control was 42.33-42.67 for 15 seconds which significantly showed that the anti-MRSA molecule A_2 did not affected the HBR.Conclusions:Anti-MRSA molecule from Streptomyces sp PVRK-I was isolated and biomedical studies in Zebrafish model assessed that the molecule was non toxic at the minimal inhibitory concentration of MRSA.

Molecular Design of Conjugated Small Molecule Nanoparticles for Synergistically Enhanced PTT/PDT

Simultaneous photothermal therapy(PTT)and photodynamic therapy(PDT)is beneficial for enhanced cancer therapy due to the synergistic effect.Conventional materials developed for synergistic PTT/PDT are generally multicomponent agents that need complicated preparation procedures and be activated by multiple laser sources.The emerging monocomponent diketopyrrolopyrrole(DPP)-based conjugated small molecular agents enable dual PTT/PDT under a single laser irradiation,but suffer from low singlet oxygen quantum yield,which severely restricts the therapeutic efficacy.Herein,we report acceptor-oriented molecular design of a donor-acceptor-donor(D-A-D)conjugated small molecule(IID-ThTPA)-based phototheranostic agent,with isoindigo(IID)as selective acceptor and triphenylamine(TPA)as donor.The strong D-A strength and narrow singlet-triplet energy gap endow IID-ThTPA nanoparticles(IID-ThTPA NPs)high mass extinction coefficient(18.2 L g^-1 cm^-1),competitive photothermal conversion efficiency(35.4%),and a dramatically enhanced singlet oxygen quantum yield(84.0%)comparing with previously reported monocomponent PTT/PDT agents.Such a high PTT/PDT performance of IID-ThTPA NPs achieved superior tumor cooperative eradicating capability in vitro and in vivo.

Role of the combination of biologics and/or small molecules in the treatment of patients with inflammatory bowel disease

Inflammatory bowel disease(IBD)is a group of chronic diseases that includes ulcerative colitis,Crohn’s disease,and indeterminate colitis.Patients with IBD require prolonged treatment and high utilization of healthcare resources for proper management.The treatment of patients with IBD is focused on achieving therapeutic goals including clinical,biochemical,and endoscopic variables that result in improvement of the quality of life and prevention of disability.Advanced IBD treatment includes tumor necrosis factor inhibitors,integrin antagonist,antagonist of the p40 subunit of interleukin 12/23,and small molecule drugs.However,despite the multiple treatments available,about 40%of patients are refractory to therapy and present with persistent symptoms that have a great impact on their quality of life,with hospitalization and surgery being necessary in many cases.Dual therapy,a strategy sometimes applicable to refractory IBD patients,includes the combination of two biologics or a biologic in combination with a small molecule drug.There are two distinct scenarios in IBD patients in which this approach can be used:(1)Refractory active luminal disease without extraintestinal manifestations;and(2)patients with IBD in remission,but with active extraintestinal manifestations or immune-mediated inflammatory diseases.This review provides a summary of the results(clinical response and remission)of different combinations of advanced drugs in patients with IBD,both in adults and in the pediatric population.In addition,the safety profile of different combinations of dual therapy is analyzed.The use of newer combinations,including recently approved treatments,the application of new biomarkers and artificial intelligence,and clinical trials to establish effectiveness during long-term followup,are needed to establish new strategies for the use of advanced treatments in patients with refractory IBD.