Effects of Low Temperature and Low Light on Physiology of Tomato Seedlings

The physiological changes and the mechanism of stress tolerance in tomato were studied under low temperature and low light conditions. Two growth chamber experiments evaluated three temperatures regimes under standard and relatively low illumination levels with three tomato genotypes. Both experiments used a completely randomized split-plot design (CRD), with temperature regime as the main plot and tomato genotype as the split-plot. The three tomato varieties were “Fenyan No.1”, “SV0313TG”, and “Ousa”. In both experiments, activity of superoxide dismutase (SOD) and peroxidases (POD) in tomato seedlings decreased under low temperature regime and the combination of low temperature and low light. Decreasing temperature had the greatest effect on the increase in enzyme activity. Decrease in POD activity was the greatest under low light and low temperature. The concentration of malondialdehyde (MDA) in plant tissue also decreased under low temperature (20°C/10°C day/night) compared to the standard temperature control (25°C/16°C day/night), but increased at 15°C/5°C day/night temperatures in both experiments and was the greatest under the lowest light and temperature conditions. In both experiments, proline concentrations were the greatest under the standard light intensity (30,000 lux), and proline concentrations increased as temperature decreased. The content of soluble sugar decreased under only low temperature stress but increased under double stresses. The relative value of osmotic potential increased a little under low temperature stress but decreased under double stresses.

Impact of nutrient solutions under inorganic substrate soilless cultivation on plant growth,fruit yield and quality of tomato

Soilless cultivation has been widely used in tomato(Solanum lycopersicum)production.The objectives of this research are to evaluate the impacts of five nutrient solutions under soilless cultivation on plant growth,fruit yield and fruit quality in tomatoes.Four experiments were conducted with six treatments(five nutrient solutions plus one control)in six-cherry tomato cultivars and two big fruited tomato cultivars and 12 traits were observed and evaluated.The results showed that each of the five solutions increased plant growth and fruit yield,and improved the fruit quality.Compared to the control,the nutrient solution treatments increased 91.3%for number of fruits on base fruit cluster,12.1%for height,and 26.3%for stem diameter in the 2017-experiment;17.1%for vitamin C,13.8%for soluble solids,and 20.8%for total soluble sugar content in 2018-experiment one;28.1%for number of fruit cluster,25.8%for fruit yield,9.4%for number of fruit per cluster,and 13.3%for single fruit weight in 2018-experiment two;and 27.7%for vitamin C,14.0%for soluble solids,18.1%for total soluble sugar content,and 14.6%for fruit yield in the 2019-experiment.The solution decreased the chemical nitrate content 16.2%in the 2018-experiment and 43.7%in the 2019-experiment,and decreased the fruit cracking rate by 87%.Treatment 2 with higher nutrient component content showed the best results of the five treatments.The significant high positive correlation among the beneficial traits,fruit yield,soluble solids,total soluble sugar content,and vitamin C,and high negative correlation between each of the four traits and nitrate content were observed,indicating that soilless cultivation can increase tomato yield with higher nutritional components and decreased nitrate content.This research provides useful information for utilizing nutrient solutions supplied to tomato soilless cultivation.

Electrostatic and hydrophobic interaction cooperative nanochaperone regulates protein folding

Natural molecular chaperones utilize spatially ordered multiple molecular forces to effectively regulate protein folding.However,synthesis of such molecules is a big challenge.The concept of“aggregate science”provides insights to construct chemical entities(aggregates)beyond molecular levels to mimic both the structure and function of natural chaperone.Inspired by this concept,herein we fabricate a novel multi-interaction(i.e.,electrostatic and hydrophobic interaction)cooperative nanochaperone(multi-co-nChap)to regulating protein folding.This multi-co-nChap is fabricated by rationally introducing electrostatic interactions to the surface(corona)and confined hydrophobic microdomains(shell)of traditional single-hydrophobic interaction nanochaperone.We demonstrate that the corona electrostatic attraction facilitates the diffusion of clients into the hydrophobic microdomains,while the shell electrostatic interaction balances the capture and release of clients.By finely synergizing corona electrostatic attraction with shell electrostatic repulsion and hydrophobic interaction,the optimized multi-co-nChap effectively facilitated de novo folding of nascent polypeptides.Moreover,the synergy between corona electrostatic attraction,shell electrostatic attraction and shell hydrophobic interaction significantly enhanced the capability of multi-co-nChap to protect native proteins from denaturation at harsh temperatures.This work provides important insights for understanding and design of nanochaperone,which is a kind of ordered aggregate with chaperone-like activity that beyond the level of single molecule.

Protein@PP-Zn nanocomplex assembled by coordination of zinc ions used for intracellular protein delivery

In recent years,intracellular delivery of protein drugs has attracted great attention,and polymer-based systems have been extensively exploited to develop efficient and safe carriers.However,efficient intracellular delivery of protein drugs remains a challenge because of the cell membrane barrier and endosome entrapment.Herein,we report a protein@PP-Zn nanocomplex,which consists of an imidazole-containing block polymer poly(ethylene glycol)-block-poly(β-amino ester)(PEG-b-PAE(Im),PP),zinc ions,and protein drugs,for efficient intracellular protein delivery.PEG-b-PAE(Im)could conjugate proteins via the bridging effect of zinc ions which simultaneously coordinate with imidazole groups on polymer and electron donor groups,such as imidazole and primary amine groups,on protein to improve the loading stability of proteins.Under a slightly acidic environment near cancer cells,the protonation of PAE(Im)backbone increases the positive charge density of the nanocomplex and promotes endocytosis.While under a more acidic environment in endosomes,further protonation of imidazole groups leads to the disintegration of the nanocomplex and the breakdown of endosomes because of the proton sponge effect.Finally,protein is released into the cytoplasm.With the assistance of the nanocomplex,proteins with different sizes and isoelectric points are effectively delivered into cells.This work provides a stable,efficient and universal strategy for intracellular protein delivery.

Synthesis and ultraviolet/aggregation-induced emission investigation of novel tetraphenylvinyl hydrazone derivatives: efficient multimodal chemosensors for fluoride ion

Herein,three novel tetraphenylethylene hydrazone chemosensors TC12,SC16,and TC16 are prepared for the selective detection of F−.Two NH and one C=N units are incorporated into the sensors for better colorimetric responses,whereas the tetraphenyl unit is in charge of the aggregation-induced emission effect.Among them,compounds SC16 and TC16 form stable gels with some organic solvents.All the tetrahydrofuran/H2O solutions of the three compounds exhibit aggregation-induced emission effect,whereby the fluorescence emission increases by varying degrees with the volume of poor solvent water.Moreover,good aggregation-induced emission effects are observed in the self-assembly of SC16 and TC16.As a sample chemosensor,TC12 in tetrahydrofuran responds to F−selectively with high sensitivity,with the colorimetric and fluorometric detection limits of 8.25×10^(−7) mol·L^(-1) and 2.69×10^(−7) mol·L^(-1),respectively.The reversible gel-sol-gel phase transition and color changes indicate that both SC16-dimethyl sulfoxide and TC16-ethyl acetate gels specifically respond to F-with good sensitivity.The detection results are well supported by ultraviolet-visible spectroscopy,fluorescent spectroscopy,and 1H nuclear magnetic resonance.More importantly,the driving forces of gelation are visually clarified through the single crystal X-ray analysis of compound TOMe.

Dynamic covalent nano-networks comprising antibiotics and polyphenols orchestrate bacterial drug resistance reversal and inflammation alleviation

New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks(aDCNs)composing antibiotics bearing multiple primary amines,polyphenols,and a cross-linker acylphenylboronic acid.Mechanistically,the iminoboronate bond drives the formation of aDCNs,facilitates their stability,and renders them highly responsive to stimuli,such as low pH and high H2O2 levels.Besides,the representative A1B1C1 networks,composed of polymyxin B1(A1),2-formylphenylboronic acid(B1),and quercetin(C1),inhibit biofilm formation of drug-resistant Escherichia coli,eliminate the mature biofilms,alleviate macrophage inflammation,and minimize the side effects of free polymyxins.Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model.The facile synthesis,excellent antimicrobial performance,and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.

Injectable dual glucose-responsive hydrogel-micelle composite for mimicking physiological basal and prandial insulin delivery

For type 1 and advanced type 2 diabetic patients, insulin replacement therapy with simulating on-demand prandial and basal insulin secretion is the best option for optimal glycemic control. However, there is no insulin delivery system yet could mimic both controlled basal insulin release and rapid prandial insulin release in response to real-time blood glucose changes. Here we reported an artificial insulin delivery system, mimicking physiological basal and prandial insulin secretion, to achieve real-time glycemic control and reduce risk of hypoglycemia. A phenylboronic acid(PBA)/galactosyl-based glucose-responsive insulin delivery system was prepared with insulin-loaded micelles embedded in hydrogel matrix. At the hyperglycemic state, both the hydrogel and micelles could swell and achieve rapid glucose-responsive release of insulin, mimicking prandial insulin secretion.When the glucose level returned to the normal state, only the micelles partially responded to glucose and still released insulin gradually. The hydrogel with increased crosslinking density could slow down the diffusion speed of insulin inside, resulting in controlled release of insulin and simulating physiological basal insulin secretion. This hydrogel-micelle composite insulin delivery system could quickly reduce the blood glucose level in a mouse model of type 1 diabetes, and maintain normal blood glucose level without hypoglycemia for about 24 h. This kind of glucose-responsive hydrogel-micelle composite may be a promising candidate for delivery of insulin in the treatment of diabetes.

Biomedical polymers: synthesis, properties, and applications

Biomedical polymers have been extensively developed for promising applications in a lot of biomedical fields, such as therapeutic medicine delivery, disease detection and diagnosis, biosensing, regenerative medicine, and disease treatment. In this review, we summarize the most recent advances in the synthesis and application of biomedical polymers, and discuss the comprehensive understanding of their property-function relationship for corresponding biomedical applications. In particular, a few burgeoning bioactive polymers, such as peptide/biomembrane/microorganism/cell-based biomedical polymers, are also introduced and highlighted as the emerging biomaterials for cancer precision therapy. Furthermore, the foreseeable challenges and outlook of the development of more efficient, healthier and safer biomedical polymers are discussed. We wish this systemic and comprehensive review on highlighting frontier progress of biomedical polymers could inspire and promote new breakthrough in fundamental research and clinical translation.

Phosphorylcholine polymer nanocapsules prolong the circulation time and reduce the immunogenicity of therapeutic proteins

Protein therap34 wherein therapeutic proteins are delivered to treat disorders, is considered the safest and most direct approach for treating diseases. However, its applications are highly limited by the paucity of efficient strategies for delivering proteins and the rapid clearance of therapeutic proteins in vivo after their administration. Here, we demonstrate a novel strategy that can significantly prolong the circulation time of therapeutic proteins as well as minimize their immunogenicity. This is achieved by encapsulating individual protein molecules with a thin layer of crosslinked phosphorylcholine polymer that resists protein adsorption. Through extensive cellular studies, we demonstrate that the crosslinked phosphorylcholine polymer shell effectively prevents the encapsulated protein from being phagocytosed by macrophages, which play an essential role in the clearance of nanoparfides in vivo. Moreover, the polymer shell prevents the encapsulated protein from being identified by immune cells. As a result, immune responses against the therapeutic protein are effectively suppressed. This work describes a feasible method to prolong the circulation time and reduce the immunogenicity of therapeutic proteins, which may promote the development and application of novel protein therapies in the treatment of diverse diseases.

Calixarene-integrated nano-drug delivery system for tumortargeted delivery and tracking of anti-cancer drugsin vivo

Nano-drug delivery systems(nanoDDS)have been extensively investigated clinically to improve the therapeutic effect of anticancer drugs.However,the complicated synthesis during the preparation as well as the potential drug leakage during transportation has greatly limited their general application.In this work,a calixarene-integrated nanoDDS(CanD)that achieves tumor-targeted delivery and tracking of anti-cancer drugs in vivo is presented.The hypoxia-responsive calixarene(SAC4A)exhibits high binding affinity to a series of anti-cancer drugs and rhodamine B(RhB)under normoxic condition while decreasing the binding affinity under hypoxic condition,which leads to the drug release and fluorescence recovery simultaneously.Furthermore,the hypoxia-responsiveness of SAC4A conveys CanD with tumor-targeting ability,resulting in the enrichment of the drug in tumors and enhancement in tumor suppression in mice.Moreover,CanD could become a general platform allowing the delivery of a wide scope of anti-cancer drugs that have strong host-guest interaction with SAC4A.

Recent advances and future challenges in the use of nanoparticles for the dispersal of infectious biofilms

Increasing occurrence of intrinsically antimicrobial-resistant,human pathogens and the protective biofilm-mode in which they grow,dictates a need for the alternative control of infectious biofilms.Biofilm bacteria utilize dispersal mechanisms to detach parts of a biofilm as part of the biofilm life-cycle during times of nutrient scarcity or overpopulation.We here identify recent advances and future challenges in the development of dispersants as a new infection-control strategy.Deoxyribonuclease(DNase)and other extracellular enzymes can disrupt the extracellular matrix of a biofilm to cause dispersal.Also,a variety of small molecules,reactive oxygen species,nitric oxide releasing compounds,peptides and molecules regulating signaling pathways in biofilms have been described as dispersants.On their own,dispersants do not inhibit bacterial growth or kill bacterial pathogens.Both natural,as well as artificial dispersants,are unstable and hydrophobic which necessitate their encapsulation in smart nanocarriers,like p H-responsive micelles,liposomes or hydrogels.Depending on their composition,nanoparticles can also possess intrinsic dispersant properties.Bacteria dispersed from an infectious biofilm end up in the blood circulation where they are cleared by host immune cells.However,this sudden increase in bacterial concentration can also cause sepsis.Simultaneous antibiotic loading of nanoparticles with dispersant properties or combined administration of dispersants and antibiotics can counter this threat.Importantly,biofilm remaining after dispersant administration appears more susceptible to existing antibiotics.Being part of the natural biofilm life-cycle,no signs of"dispersant-resistance"have been observed.Dispersants are therewith promising for the control of infectious biofilms.

An Exceptional Broad-Spectrum Nanobiocide for Multimodal and Synergistic Inactivation of Drug-Resistant Bacteria

This study reports the fabrication of a novel photothermal material formed via the physical blending of excess lauric acid(LA)and cupric acetate,followed by efficient ligand exchange.Surprisingly,the copper–LA complex exhibited a 12-fold enhancement of the molar extinction coefficient in the nearinfrared(NIR)region relative to aqueous cupric acetate.Inspired by this interesting finding,we formulated these photothermal materials into colloidally dispersed nanoparticles via a technique that combined nanoprecipitation and in situ surface polymerization for antibacterial studies.The resultant nanoparticles exhibited rapid and stable photothermal responses to NIR irradiation,with a 4-fold enhanced photothermal conversion efficiency relative to aqueous cupric acetate.Since a positively charged monomer was incorporated during in situ surface polymerization,these positively charged nanoparticles were ingested efficiently and subsequently digested by drug-resistant bacteria.By combining the LA-mediated membrane-damaging effect,copper-mediated Fenton-like reaction,as well as the photothermal effect of the copper–LA complex,a broad-spectrum,multimodal,and synergistic antibacterial effect was achieved both in vitro and in vivo,with the killing efficiency up to 99.99%for ampicillin-resistant Escherichia coli(Ampr E.coli)and 99.9999%for methicillinresistant Staphylococcus aureus(MRSA).Our newly developed nanobiocide represents a class of exceptional broad-spectrum antibacterial materials,holding great potential for treating drug-resistant infections in clinical settings.

Complex micelles with the bioactive function of reversible oxygen transfer

复杂 micelle 作为血红素，有可逆的氧转移的 biaoactive 函数的功能的模型 poly 通过 diblock 共聚物的层次汇编被构造了(乙烯乙二醇)-blockpoly(4-vinylpyridine-co-N-heptyl-4-vinylpyridine)( PEG-b-P ( 4VP-co-4VPHep ))， tetrakis ( 4-sulfonatophenyl ) porphinato 铁( II )( Fe ( II ) TPPS )和 -cyclodextrin (-CD)。含氧 Fe (II ) TPPS 更暗淡因为 Fe (II ) TPPS 通过主人客人被包括进 CD 的洞，成功地被禁止相互作用。与 pyridine 组一起协调的 Fe (II ) TPPS 作为活跃地点工作 reversibly 绑 dioxygen。在 adition，主人客人包括(-CD/Fe(II)TPPS) 在复杂 micelle 的恐水病的核心被包含并且紧由 P4VP 链修理了。在水的答案拉长组成稳定复杂 micelle 的结构象一样的壳的吸水的木钉块赋予复杂 micelle 以足够的血发行量时间。Dioxygen 能被绑在位于限制空间和 dioxygen 的有约束力版本的过程的优秀可逆性的 Fe (II ) TPPS 能被完成。第四级的胺 N-heptyl-4-vinylpyridine 能强制丰富的 S < 潜水艇 class= “ a-plus-plus ” > 2 O < 潜水艇 class= “ a-plus-plus ” > 4 < 啜 class= “ a-plus-plus ” > 进复杂 micelle 的核心的 2 个 离子处理便于自我减小。Dioxygen 使内收(Fe (II ) TPPS (O < 潜水艇 class= “ a-plus-plus ” > 2 )) 被由 cyclodextrin 和提高能力抵抗亲核的分子的复杂 micelle 的核心的洞构造的双恐水病的障碍有效地保护。因此，讲道理地设计的 amphiphilic 结构能作为有希望的人工的 O 工作 < 潜水艇 class= “ a-plus-plus ” > 2 搬运人。潜在地，复杂 micelle 能被期望改进与组织缺氧连接的疾病的治疗。

Self-assembled nanochaperones enable the disaggregation of amyloid insulin fibrils

The deposition of highly ordered amyloid fibrils is recognized as a hallmark of amyloidosis diseases such as Alzheimer’s disease and Parkinson’s disease.Disaggregating the amyloid fibrils is considered as one of the effective strategies for the control and treatment of amyloidosis diseases.In this article,by simulating the function of natural molecular chaperones,co-assembled block copolymer micelles with coordination groups of nitrilotriacetic acid(NTA)and hydrophobic microdomains of poly(Nisopropylacrylamide)(PNIPAM)on the surface were used as nanochaperones(n Chaps)to disaggregate amyloid insulin fibrils.Zinc ions chelated by NTA can bind the histidine imidazole residues while the PNIPAM microdomains can interact with the exposed hydrophobic sites on the amyloid insulin fibrils,which synergistically perturb the stability of amyloid insulin fibrils,loosen their structure,and finally promote their disaggregation.A combination of characterizations with fluorescence spectroscopy,transmission electron microscopy(TEM),dynamic hight scattering(DLS),and quartz crystal microbalance(QCM)demonstrated that mature amyloid insulin fibrils were completely disaggregated after incubating with n Chaps for 90 h.This study may provide a promising strategy for the development of n Chaps for the treatment of amyloidosis diseases.

In-biofilm generation of nitric oxide using a magnetically-targetable cascade-reaction container for eradication of infectious biofilms

Cascade-reaction chemistry can generate reactive-oxygen-species that can be used for the eradication of infectious biofilms.However,suitable and sufficient oxygen sources are not always available near an infection site,while the reactive-oxygen-species generated are short-lived.Therefore,we developed a magnetic cascade-reaction container composed of mesoporous Fe_(3)O_(4)@SiO_(2) nanoparticles containing glucose-oxidase and L-arginine for generation of reactive-oxygen-species.Glucose-oxidase was conjugated with APTES facilitating coupling to Fe_(3)O_(4)@SiO_(2) nanoparticles and generation of H_(2)O_(2) from glucose.L-arginine was loaded into the nanoparticles to generate NO from the H_(2)O_(2) generated.Using an externally-applied magnetic field,cascade-reaction containers could be homogeneously distributed across the depth of an infectious biofilm.Cascade-reaction containers with coupled glucose-oxidase were effective in killing planktonic,Gram-positive and Gram-negative bacteria.Additional efficacy of the L-arginine based second cascade-reaction was only observed when H_(2)O_(2) as well as NO were generated in-biofilm.In vivo accumulation of cascade-reaction containers inside abdominal Staphylococcus aureus biofilms upon magnetic targeting was observed real-time in living mice through an implanted,intra-vital window.Moreover,vancomycin-resistant,abdominal S.aureus biofilms could be eradicated consuming solely endogenous glucose,without any glucose addition.Herewith,a new,non-antibiotic-based infection-control strategy has been provided,constituting a welcome addendum to the shrinking clinical armamentarium to control antibiotic-resistant bacterial infections.

Neuroprotective Nanoscavenger Induces Coaggregation of β-Amyloid and Facilitates Its Clearance in Alzheimer’s Disease Brain

The accumulation of solubleβ-amyloid aggregates(sAβs)is one of the main culprits in Alzheimer’s disease(AD)progression,which can lead to synaptic dysfunction and subsequent neurodegeneration.Herein,we describe a nanoscavenger with novel structure that can cross the blood–brain barrier(BBB),accurately collect neurotoxic sAβs,and facilitate amounts ofβ-amyloid(Aβ)clearance.