Combined peripheral natural killer cell and circulating tumor cell enumeration enhance prognostic efficiency in patients with metastatic triple-negative breast cancer

Objective：Triple-negative breast cancer（TNBC）is a heterogeneous disease with poor prognosis.Circulating tumor cells（CTCs）are a promising predictor for breast cancer prognoses but their reliability regarding progression-free survival（PFS）is controversial.We aim to verify their predictive value in TNBC.Methods：In present prospective cohort study,we used the Pep@MNPs method to enumerate CTCs in baseline blood samples from 75 patients with TNBC（taken at inclusion in this study）and analyzed correlations between CTC numbers and outcomes and other clinical parameters.Results：Median PFS was 6.0（range：1.0–25.0）months for the entire cohort,in whom we found no correlations between baseline CTC status and initial tumor stage（P=0.167）,tumor grade（P=0.783）or histological type（P=0.084）.However,among those getting first-line treatment,baseline CTC status was positively correlated with ratio of peripheral natural killer（NK）cells（P=0.032）,presence of lung metastasis（P=0.034）and number of visceral metastatic site（P=0.037）.Baseline CTC status was predictive for PFS in first-line TNBC（P=0.033）,but not for the cohort as a whole（P=0.118）.This prognostic limitation of CTC could be ameliorated by combining CTC and NK cell enumeration（P=0.049）.Conclusions：Baseline CTC status was predictive of lung metastasis,peripheral NK cell ratio and PFS in TNBC patients undergoing first-line treatment.We have developed a combined CTC-NK enumeration strategy that allows us to predict PFS in TNBC without any preconditions.

Terminus-immobilization effect on peptide conformations and peptide–peptide interactions

Peptide-modified delivery systems are enabling the improvement of the targeting specificity,biocompatibility,stability,etc.However,the precise design of a peptide-decorated surface for a designated function has remained to be challenging due to a lack of mechanistic understanding of the interactions between surface-bound peptide ligands and their receptors.Enlightened by the recent report on pairwise interactions between peptides in the solution state and surface-immobilized state,we used computational simulations to explore the contributing mechanisms underlining the observed binding affinity characteristics.Molecular dynamics simulations were performed to sample and compare conformations of homo-octapeptides free in solution(mobile peptides)and bound to the surface(N-terminal fixed peptides).We found that peptides converged to more extended and rigid conformations when immobilized to the surface and confirmed that the extended structures could increase the space available to counter-interacting peptides during the peptide–peptide interactions.In addition,studies on interactions between stationary and mobile peptides revealed that main-chain/side-chain and side-chain/side-chain hydrogen bonds play an important role.The presented efforts in this work may provide supportive references for peptide design and modification on the nanoparticle surface as well as guidance for analyzing peptide–receptor interactions through an emphasis on hydrogen bonds during peptide design and an understanding of the influence on the binding affinity by the sequence-dependant conformational changes after peptide immobilization.

Dual-functional extracellular vesicles enable synergistic treatment via m^(6)A reader YTHDF1-targeting epigenetic regulation and chemotherapy

Chemotherapy remains one of the most prevailing strategies for cancer treatment.However,its treatment effect is hampered by drug resistance,nonspecific tumor targeting,and severe toxic side effects.Combination chemotherapy with synergistic effect has become an attractive tumor therapy.N6-methyladenosine(m6A)regulators determine the fate of m6A-modified transcripts and play vital roles in cancer development and drug resistance.Gene therapy such as small interfering RNA(siRNA)is a promising strategy to reduce the abnormal gene expression of m6A regulators.However,its poor selectivity and high systemic toxicity necessitate the use of delivery vectors to target specific cells and tissues.Here,we constructed a dual-functional targeted nanodrug platform for the synergetic m6A-associated epigenetic regulation and chemotherapy of ovarian cancer.We encapsulated siRNA targeting the m6A reader YT521-B homology(YTH)N6-methyladenosine RNA-binding protein 1(YTHDF1)and docetaxel(DTX),the first-line chemotherapeutic agent of ovarian cancer,into mesenchymal stem cell-derived small extracellular vesicles(MsEVs).This nanosystem exhibits significant tumor targeting and endo/lysosomal escape of siYTHDF1.It effectively depletes YTHDF1 and suppresses the protein translation of eukaryotic translation initiation factor 3 subunit C(EIF3C)in an m6A-dependent manner.The combination of YTHDF1-targeting epigenetic regulation significantly enhances the anti-tumor effect of DTX and effectively inhibits ovarian cancer progression without causing significant systemic toxicity.This co-delivery nanoplatform offers a promising approach for combinational cancer treatment,showing improved anti-tumor efficacy through the synergistic effects of epigenetic regulation and chemotherapeutic inhibition.

Formulated nano-liposomes for reversal of cisplatin resistance in NSCLC with nucleus-targeting peptide

Cell membrane-engineered nano-delivery systems have evolved as a promising strategy to enhance drug bioavailability,offering an alternative for reversing drug resistance in cancer therapy.Herein,a formulated nano-liposome that fabricated by hybridizing cisplatin-resistant A549 cell line(A549/cis)cancer cell membrane and phospholipids for co-delivery of cisplatin and nuclear protein zeste homolog 2(EZH2)-targeting peptide EIP103,referred to as cLCE,was developed.In vitro results indicated that the formulated nano-liposome can efficiently inhibit A549/cis cancer cell invasion and metastasis through the down-regulation of Ncadherin and vimentin proteins.Mechanistic studies demonstrated that the reduction of nerve growth factor receptor(NGFR)levels and the increase of peroxisome proliferator-activated receptorγ(PPARγ)levels achieved by EIP103 may contribute to the reversal of cisplatin resistance.In vivo results demonstrated that the encapsulation of both cisplatin and EIP103 within cLCE leads to increased intratumoral accumulation and prolonged survival in A549/cis cancer-bearing mice as compared to the individual drugs alone.This can be attributed to the enhanced tumor homing capability of cLCE achieved through the presence of inherited membrane proteins derived from A549/cis cells.Taken together,this study may provide a highly promising therapeutic strategy to improve clinical treatments for cisplatin-resistance non-small-cell lung cancer(NSCLC)as well as other malignant cancers.

Nano-imaging agents for brain diseases: Environmentally responsive imaging and therapy

Precise imaging is essential for the accurate diagnosis and surgical guidance of brain diseases but it is challenging due to the difficulties in crossing the blood-brain barrier(BBB),the difficulties in disease lesion targeting,and the limited contrast in the brain environment.Nano-imaging agents were characterized by functionalized modifications,high contrast,small size,and high biocompatibility,thus providing advantages in BBB crossing,brain targeting,imaging resolution,and real-time monitoring,holding great potential in brain disease imaging.Specific characteristics in brain environment and brain diseases(e.g.,marker proteins on the BBB,the pathogenic proteins in the neurodegenerative diseases or brain tumors,and the tumor and inflammatory microenvironment)provide opportunities for the functionalized nano-imaging agents to improve BBB crossing and disease targeting.Moreover,the versatile nano-imaging agents are endowed with therapeutic agents to facilitate the theranostics of brain diseases.Here,we summarized the common materials and imaging techniques of nano-imaging agents and their imaging treatment applications.We discussed their BBB penetration,environmental response for disease targeting,and therapeutic effects.We also provided insights on the advantages,challenges,and application of nano-imaging agents in detecting and treating brain diseases such as neurodegenerative diseases,brain tumors,stroke,and traumatic brain injury.These discussions will help develop nano-imaging agents-based theranostic platforms for the precise diagnosis and treatment of brain diseases.

Nanomaterials for visualized tumor surgical navigation and postoperative recurrence inhibition

Preoperative localization of the tumor sites and intraoperative real-time monitoring are essential for precise surgery but are meanwhile challenging due to the lack of high-resolution,easy-to-operate,and fast visualization techniques.On the other hand,tumor recurrence and metastasis after surgery greatly reduce the survival rate of patients.Intervening tumor recurrence during surgery is a future direction of tumor treatment.Nanomaterials with external condition responsiveness(light,ultrasound,and magnetic field)can accurately assist intraoperative detection and surgical resection due to their functions such as tumor cell targeting,fluorescence imaging,and real time monitoring,providing a more accurate,shorter duration,and visualization method of surgical resection.Moreover,nanomaterials are versatile and can easily be tailored for application in different tumors.Locally filled or systemically circulating nanomaterials with slow drug release and residual tumor cell-targeting ability have promising applications in inhibiting tumor recurrence.Here,we review surgical navigation and postoperative recurrence interventional nanomaterials and their landscape in guiding tumor treatment.We summarize the classification and characteristics of these nanomaterials and discuss their application in the surgical navigation and recurrence inhibition of different tumors.We also provide an outlook on the challenges and future development of nanomaterials for visualized tumor surgical navigation and postoperative recurrence inhibition.

Principles of amino-acid–ribonucleotide interaction revealed by binding affinities between homogeneous oligopeptides and singlestranded RNA molecules

We have determined the binding strengths between ribonucleotides of adenine(A),guanine(G),uracil(U),and cytosine(C)in homogeneous single-stranded ribonucleic acids(ssRNAs)and homo-decapeptides consisting of 20 common amino acids.We use a bead-based fluorescence assay for these measurements in which decapeptides are immobilized on the bead surface and ssRNAs are in solutions.The results provide a molecular basis for analyzing selectivity,specificity,and polymorphisms of amino-acid–ribonucleotide interactions.Comparative analyses of the distribution of the binding energies reveal unique binding strength patterns assignable to each pair of amino acid and ribonucleotide originating from the chemical structures.Pronounced favorable(such as Arg–G)and unfavorable(such as Met–U)binding interactions can be identified in selected groups of amino acid and ribonucleotide pairs that could provide basis to elucidate energetics of amino-acid–ribonucleotide interactions.Such interaction selectivity,specificity,and polymorphism manifest the contributions from RNA backbone,RNA bases,as well as main chain and side chain of the amino acids.Such characteristics in peptide–RNA interactions might be helpful for understanding the mechanism of protein–RNA specific recognition and the design of RNA nano-delivery systems based on peptides and their derivatives.

基于多肽和蛋白质分子的纳米生物界面效应及其应用研究

通过对纳米结构进行表面生物和化学修饰,能够赋予其崭新的界面性质.本文概述了纳米颗粒表面共价修饰和非共价修饰多肽和蛋白质的常用方法,对比了两种修饰方法的优缺点以及构筑纳米生物结构存在的问题;并介绍了多肽和蛋白质界面修饰在改善纳米颗粒生物稳定性、生物分布和靶向性方面的研究工作;在此基础上介绍了纳米生物结构基于抗原-抗体特异性识别在生物检测领域的应用;此外,简单介绍了纳米生物结构在应用过程中所面临的挑战.希望本综述能够有助于科技工作者了解纳米生物结构的构筑方法及其应用方面的进展和挑战,为多肽和蛋白质修饰纳米结构的设计合成提供一些启发和思路.

纳米生物界面对淀粉样蛋白聚集的调控机制研究

本文以阿尔兹海默症的致病多肽β淀粉样蛋白(Aβ)为例,介绍了疾病相关淀粉样蛋白的分子精细结构、组装和聚集过程、聚集体形貌及神经细胞毒性的研究进展,并在此基础上以纳米生物界面对于淀粉样蛋白构象、组装结构、聚集动力学、神经细胞毒性等生物功能的调控机制进行研究.从分子水平上分析和探讨了纳米生物界面与淀粉样蛋白分子或者聚集体的相互作用方式和机理,有助于加深对淀粉样多肽和调节剂之间复杂多样的相互作用方式的理解,对深入了解淀粉样多肽的组装机理和调控机制以及探索治疗神经退行性疾病的药物设计等方面具有较大意义.

Vacuum-tuned-atmosphere induced assembly of Au@Ag core/shell nanocubes into multi-dimensional superstructures and the ultrasensitive IAPP proteins SERS detection

Utilizing vacuum-tuned-atmosphere induced dip coating method,we achieve the cross-dimensional macroscopic diverse self-assemblies by using one building block with one chemical functionality.Coordinated modulating the vacuum degree,colloid concentration and evaporation atmosphere,Au@Ag core/shell nanocubes (NCs) can controllably assemble into diverse multi-dimensional superstructures.Under 0.08 MPa,we obtained the two-dimensional (2D) stepped superstructures with continuously tunable step width.In addition,we generated a series of tailorable nanoscale-roughened 2D Au@Ag NCs superstructures at 0.04 MPa,which exhibited the label-free ultrasensitive SERS detection for the different mutants of IAPP8-37 proteins.Under 0.01 MPa,we obtained the cross-dimensional tailorable Au@Ag NCs assemblies from random to macroscale 2D and three-dimensional (3D) densest superstructures by adjusting the capping ligand-environmental molecule interactions.This is a flexible method to generate as-prepared Au@Ag core/shell NCs into well-defined macroscopic diverse superstructures and to promote the exploitation into biological applications.

Attenuation ofβ-Amyloid Toxicity In Vitro and In Vivo by Accelerated Aggregation

Accumulation and aggregation of β-amyloid（Aβ） peptides result in neuronal death, leading to cognitive dysfunction in Alzheimer＇s disease. The self-assembled Aβ molecules form various intermediate aggregates including oligomers that are more toxic to neurons than the mature aggregates, including fibrils. Thus, one strategy to alleviate Aβ toxicity is to facilitate the conversion of Aβ intermediates to larger aggregates such as fibrils. In this study, we designed a peptide named A3 that significantly enhanced the formation of amorphous aggregates of Aβ by accelerating the aggregation kinetics. Thioflavin T fluorescence experiments revealed an accelerated aggregation of Aβ monomers, accompanying reduced Aβ cytotoxicity. Transgenic Caenorhabditis elegans over-expressing amyloid precursor protein exhibited paralysis due to the accumulation of Aβ oligomers, and this phenotype was attenuated by feeding the animals with A3 peptide. These findings suggest that the Aβ aggregation-promotion effect can potentially be useful for developing strategies to reduce Aβ toxicity.

Allosteric Modulation of Human Serum Albumin Induced by Peptide Ligand

Human serum albumin （HSA） is an abundant protein in plasma that can bind and transport many small molecules, and the corresponding affinity-controlled drug delivery shows great advantage in the biological system. Peptide SA06 is a reported ligand comprising 20 amino acids, and is known to non-covalently bind with HSA to extend the lifetime and improve the pharmacokinetic performance. The structural information of the HSA-peptide complex is keen for obtainingmolecular insight of the binding mechanism. We studied the secondary structural change and structure-affinity relations of Peptide SA06 with HSA by using circular dichroism （CD） spectroscopy in solution. Noticeable allosteric effect can be identified by compositional increase of a-helix structures when the peptide was co-incubated with HSA. Furthermore, the equilibrium dissociation constant of Peptide SA06 with HSA can be determined by CD-baged method. This work provides structural evidence on the allosteric interaction between peptide ligand and HSA, and sheds light on optimization of therapeutic properties in the affinity-controlled delivery systems.

Peptide recognition by functional supramolecular nanopores with complementary size and binding sites

The precise control of the conformations of biomolecules adsorbed on a surface at the single-molecule level is significant. However, it remains a huge challenge because of the complex structure and conformation diversity of biomolecules. Herein, a ＂nanopore-confined recognition＂ strategy is proposed to manipulate the adsorption of individual valinomycin molecules at room temperature through precise design of functionalized conjugated macrocycle （CPN8） supramolecular nanopores with complementary architectures and binding sites. We revealed that CPN8 prefers to selectively recognizing valinomycin with complementary architecture because of the strong synergistic interactions between the isopropyl groups of valinomycin and the amino groups of CPN8, with valinomycin- highly oriented pyrolytic graphite （HOPG） interactions. Our perspectives at the single-molecule level will provide valuable insights to improve the design of supramolecular nanopores for conformation-selective recognition of non-conjugated molecules.

Site-specific determination of TTR-related functional peptides by using scanning tunneling microscopy

For the design and optimization of functional peptides, unravelling the structures of individual building blocks as well as the properties of the ensemble is paramount. TI＇R1, derived from human transthyretin, is a fibril-forming peptide implicated in diseases such as familial amyloid polyneuropathy and senile systemic amyloidosis. The functional peptide TTR1-RGD, based on a TFR1 scaffold, was designed to specifically interact with cells. Here, we used scanning tunneling microscopy （STM） to analyze the assembly structures of TTRl-related peptides with both the reverse sequence and the modified forward sequence. The site- specific analyses show the following： i） The TIR1 peptide is involved in assembly, nearly covering the entire length within the ordered [3-sheet structures, ii） For TTR1-RGD peptide assemblies, the TTR1 motif forms the ordered [3-sheet while the RGDS motif adopts a flexible conformation allowing it to promote cell adhesion. The key site is clearly identified as the linker residue Gly13. iii） Close inspection of the forward and reverse peptide assemblies show that in spite of the difference in chemistry, they display similar assembling characteristics, illustrating the robust nature of these peptides, iv） Glycine linker residues are included in the ^-strands, which strongly suggests that the sequence could be optimized by adding more linker residues. These garnered insights into the assembled structures of these peptides help unravel the mechanism driving peptide assemblies and instruct the rational design and optimization of sequence- programmed peptide architectures.

Nanoscale structural and electronic evolution for increased efficiency in polymer solar cells monitored by electric scanning probe microscopy

Control of blend morphology at multi-scale is critical for optimizing the power conversion efficiency(PCE)of plastic solar cells.To better understand the physics of photoactive layer in the organic photovoltaic devices,it is necessary to gain understanding of morphology and the corresponding electronic property.Herein we report the correlation between nanoscale structural,electric properties of bulk heterojunction(BHJ)solar cells and the annealing-induced PCE change.We demonstrate that the PCE of BHJ solar cells are dramatically improved(from1.3%to 4.6%)by thermal annealing,which results from P3HT crystalline stacking and the PCBM aggregation for interpenetrated network.The similar trend for annealinginduced photovoltage and PCE evolution present as an initial increase followed by a decrease with the annealing time and temperature.The surface roughness increase slowly and then abruptly after the same inflection points observed for photovoltage and PCE.The phase images in electric force microscopy indicate the optimized P3HT and PCBM crystallization for interpenetrating network formation considering the spectroscopic results as well.From the correlation between surface photovoltage,blend morphology,and PCE,we propose a model to illustrate the film structure and its evolution under different annealing conditions.This work would benefit the better design and optimization of the morphology and local electric properties of solar cell active layers for improved PCE.

Site-specific Analysis of Amyloid Assemblies by Using Scanning Tunneling Microscopy

The assembly of amyloid peptides into highly organized fibrils is one of the major characteristics of many de-generative diseases such as Alzheimer’s disease and type II diabetes.Assembly structures of amyloid peptides at liquid-solid interface can be visualized by scanning tunneling microscopy(STM)with site-specific resolution.The STM analysis can provide valuable information on the folding mechanism of amyloid peptides based on the corre-lation of surface assembly structures and fibrillation behaviors.Cases on mutational analysis of amyloid peptides by STM are also reviewed which illustrate the capacities of STM studies on amyloid assemblies.

Identifi cation of Molecular Flipping of an Asymmetric Tris(phthalocyaninato)Lutetium Triple-Decker Complex by Scanning Tunneling Microscopy/Spectroscopy

The assembling behavior and electronic properties of asymmetric tris(phthalocyaninato)lutetium triple-decker sandwich complex molecules(Lu2Pc3)on highly oriented pyrolytic graphite(HOPG)surfaces have been studied by scanning tunneling microscopy/spectroscopy(STM/STS)methods.Phase transitions were observed at different bias polarities,involving an ordered packing arrangement with fourfold symmetry at negative bias and an amorphous arrangement at positive bias.Molecular switching behaviour for individual Lu2Pc3 molecules was reported here according to the bias-polarity-induced flipping phenomena and the peak shift in dI/dV versus V curves at different voltage scanning directions.The sensitive response of the strong intrinsic molecular dipole to an external electric field is proposed to be responsible for molecular switching of Lu_(2)Pc_(3)at the solid/liquid interface.

Targeting the CXCR4/CXCL12 axis with the peptide antagonist E5 to inhibit breast tumor progression

Emerging evidence has demonstrated that stromal cell-derived factor 1(SDF-1)and its cognate receptor CXCR4 have critical roles in tumorigenesis,angiogenesis and metastasis.In this study,we demonstrated the significant inhibitory effects of a novel chemically synthetic peptide(E5)on the CXCR4/CXCL12 axis in breast cancer both in vitro and in vivo.E5 was capable of specifically binding to the murine breast cancer cell line 4T1,remarkably inhibiting CXCL12-or stromal cell(MS-5)-induced migration,and adhesion and sensitizing 4T1 cells to multiple chemotherapeutic drugs.Furthermore,E5 combined with either paclitaxel or cyclophosphamide significantly inhibited tumor growth in a breast cancer model.Mechanistic studies implied that E5 can inhibit the expression of CXCR4 to block the CXCL12-mediated recruitment of endothelial progenitor cells and repress CXCR4 downstream of the Akt and Erk signaling pathway,which are involved in tumor angiogenesis and progression.Further pharmacokinetic evaluation suggested that E5 has an acceptable stability,with a half-life of 10 h in healthy mice.In conclusion,E5 demonstrates a promising anti-tumor effect and could be a potential chemotherapeutic sensitizer to improve current clinical breast cancer therapies.