New power of self-assembling carbonic anhydrase inhibitor: Short peptide-constructed nanofibers inspire hypoxic cancer therapy

Metal-Coordinated Supramolecular Self-Assemblies for Cancer Theranostics

Metal-coordinated supramolecular nanoassemblies have recently attracted extensive attention as materials for cancer theranostics. Owing to their unique physicochemical properties, metal-coordinated supramolecular self-assemblies can bridge the boundary between traditional inorganic and organic materials. By tailoring the structural components of the metal ions and binding ligands, numerous multifunctional theranostic nanomedicines can be constructed. Metal-coordinated supramolecular nanoassemblies can modulate the tumor microenvironment (TME), thus facilitating the development of TME-responsive nanomedicines. More importantly, TME-responsive organic-inorganic hybrid nanomaterials can be constructed in vivo by exploiting the metal-coordinated self-assembly of a variety of functional ligands, which is a promising strategy for enhancing the tumor accumulation of theranostic molecules. In this review, recent advancements in the design and fabrication of metal-coordinated supramolecular nanomedicines for cancer theranostics are highlighted. These supramolecular compounds are classified according to the order in which the coordinated metal ions appear in the periodic table. Furthermore, the prospects and challenges of metal-coordinated supramolecular self-assemblies for both technical advances and clinical translation are discussed. In particular, the superiority of TME-responsive nanomedicines for in vivo coordinated self-assembly is elaborated, with an emphasis on strategies that enhance the accumulation of functional components in tumors for an ideal theranostic outcome.

In situ self-assembled peptide nanofibers for cancer theranostics

Self-assembled nanofibers hold tremendous promise for cancer theranostics owing to their in situ assembly, spatiotemporal responsiveness, and diverse bioactivity. Herein, this review summarizes the recent advances of self-assembled peptide nanofibers and their applications in biological systems, focusing on the dynamic process of capturing cancer cells from the outside-in. (1) In situ self-assembly in response to pathological or physiological changes. (2) Diverse functions at different locations of tumors, such as forming thrombus in tumor vasculature, constructing a barrier on the cancer cell membrane, and disrupting the cancer organelles. Of note, with the assembly/aggregation induced residence (AIR) effect, the nanofibers could form a drug depot in situ for sustained release of chemotherapeutic drugs to increase their local concentration and prolong the residence time. Finally, perspectives toward future directions and challenges are presented to further understand and expand this exciting field.

A crosslinked colloidal network of peptide/nucleic base amphiphiles for targeted cancer cell encapsulation

The use of peptide amphiphiles (PAs) is becoming increasingly popular, not only because of their unique self-assembly properties but also due to the versatility of designs, allowing biological responsiveness, biocompatibility, and easy synthesis, which could potentially contribute to new drug design and disease treatment concepts. Oligonucleotides, another major functional bio-macromolecule class, have been introduced recently as new functional building blocks into PAs, further enriching the tools available for the fabrication of bio-functional PAs. Taking advantage of this, in the present work, two nucleic base-linked (adenine, A and thymine, T) RGD-rich peptide amphiphiles (NPAs) containing the fluorophores naphthalimide and rhodamine (Nph-A and Rh-T) were designed and synthesized. The two NPAs exhibit distinctive assembly behaviours with spherical (Rh-T) and fibrous (Nph-A) morphologies, and mixing Nph-A with Rh-T leads to a densely crosslinked colloidal network (Nph-A/Rh-T) via mutually promoted supramolecular polymerization via nucleation-growth assembly. Because of the RGD-rich sequences in the crosslinked network, further research on in situ targeted cancer cell (MDA-MB-231) encapsulation via RGD-integrin recognition was performed, and the modulation of cell behaviours (e.g., cell viability and migration) was demonstrated using both confocal laser scanning microscopy (CLSM) imaging and a scratch wound healing assay.

Tailoring metal-organic frameworks-based nanozymes for bacterial theranostics

Nanozymes are next-generation artificial enzymes having distinguished features such as cost-effective, enhanced surface area, and high stability. However, limited selectivity and moderate activity of nanozymes in the biochemical environment hindered their usage and encouraged researchers to seek alternative catalytic materials. Recently, metal-organic frameworks (MOFs) characterized by distinct crystalline porous structures with large surface area, tunable pores, and uniformly dispersed active sites emerged, that filled the gap between natural enzymes and nanozymes. Moreover, by selecting suitable metal ions and organic linkers, MOFs can be designed for effective bacterial theranostics. In this review, we briefly presented the design and fabrication of MOFs. Then, we demonstrated the applications of MOFs in bacterial theranostics and their safety considerations. Finally, we proposed the major obstacles and opportunities for further development in research on the interface of nanozymes and MOFs. We expect that MOFs based nanozymes with unique physicochemical and intrinsic enzyme-mimicking properties will gain broad interest in both fundamental research and biomedical applications.

Hypoxia and pH co-triggered oxidative stress amplifier for tumor therapy

To keep fast proliferation, tumor cells are exposed to higher oxidative stress than normal cells and they upregulate the amount of some antioxidants such as glutathione (GSH) against reactive oxygen species to maintain the balance. This phenomenon is severe in hypoxic tumor cells. Although researchers have proposed a series of treatment strategies based on regulating the intracellular reactive oxygen species level, few of them are related to the hypoxic tumor. Herein, a novel organic compound (PLC) was designed by using lysine as a bridge to connect two functional small molecules, a hypoxia-responsive nitroimidazole derivative (pimonidazole) and a pH-responsive cinnamaldehyde (CA) derivative. Then, the oxidative stress amplifying ability of PLC in hypoxic tumor cells was evaluated. The acidic microenvironment of tumor can trigger the release of CA to produce reactive oxygen species. Meanwhile, large amount of nicotinamide adenine dinucleotide phosphate (NADPH) can be consumed to decrease the synthesis of GSH during the bio-reduction process of the nitro group in PLC under hypoxic conditions. Therefore, the lethal effect of CA can be amplified for the decrease of GSH. Our results prove that this strategy can significantly enhance the therapeutic effect of CA in the hypoxic tumor cells.

Self-assembled nanomaterials for biosensing and therapeutics: recent advances and challenges

Self-assembled nanomaterials (SANs) exhibit designable biofunctions owing to their tunable nanostructures and modifiable surface. Various constituent units and multi-dimensional structures of SANs provide unlimited possibilities for numerous applications. This review emphasizes the recent development of SANs in the fields of biosensing, bioimaging, and nano-drug engineering. The unit type, design concepts, material advantages, assembly driving force, nanostructure effects, drug loading performance, etc. are discussed and summarized. Finally, we briefly summarize how to assemble unique nanomaterials and point out the key challenges in this field.

Lysosome-Instructed Self-Assembly of Amino-Acid-Functionalized Perylene Diimide for Multidrug-Resistant Cancer Cells

Multidrug resistance (MDR) of cancer cells reduces chemotherapeutic efficacy by preventing drug accumulation in the cells through a drug efflux pump and lysosomal sequestration/exocytosis. Herein, to overcome such anticancer resistance, lysosome-targeted self-assembly of perylene diimide (PDI) derivatives is presented as a powerful strategy for effective and selective anticancer therapy. Stimulated by the lysosomal low pH, the amphiphilic PDI derivatives functionalized with amino acids (PDI-AAs) construct fibrous self-assembled structures inside the lysosomes, causing cancer cell apoptosis by lysosomal rupture. In contrast, negligible apoptosis was observed from normal cells by PDI-AA. The agglomerated fibrous assemblies were not removed by lysosomal exocytosis, thereby displaying a 10.7-fold higher anticancer efficacy on MDR cancer cells compared to a doxorubicin chemotherapeutic agent. The MDR-circumventing capability, along with high selectivity toward cancer cells, supports PDI-AAs as potential candidates for the treatment of MDR cancer cells by lysosome-targeted self-assembly.

Intracellular aggregation of peptide-reprogrammed small molecule nanoassemblies enhances cancer chemotherapy and combinatorial immunotherapy

The intracellular retention of nanotherapeutics is essential for their therapeutic activity. The immobilization of nanotherapeutics inside target cell types can regulate various cell behaviors. However, strategies for the intracellular immobilization of nanoparticles are limited. Herein, a cisplatin prodrug was synthesized and utilized as a glutathione (GSH)-activated linker to induce aggregation of the cisplatin prodrug/IR820/docetaxel nanoassembly. The nanoassembly has been reprogrammed with peptide-containing moieties for tumor-targeting and PD-1/PD-L1 blockade. The aggregation of the nanoassemblies is dependent on GSH concentration. Evaluations in vitro and in vivo revealed that GSH-induced intracellular aggregation of the nanoassemblies enhances therapeutic activity in primary tumors by enhancing the accumulation and prolonging the retention of the chemotherapeutics in the tumor site and inducing reactive oxygen species (ROS) generation and immunogenic cell death. Moreover, the nanoassemblies reinvigorate the immunocytes, especially the systemic immunocytes, and thereby alleviate pulmonary metastasis, even though the population of immunocytes in the primary tumor site is suppressed due to the enhanced accumulation of chemotherapeutics. This strategy provides a promising option for the intracellular immobilization of nanoparticles in vitro and in vivo.

Supramolecular Self-Assembly-Facilitated Aggregation of Tumor-Specific Transmembrane Receptors for Signaling Activation and Converting Immunologically Cold to Hot Tumors

Supramolecular self-assembling peptide systems are attracting increasing interest in the field of cancer theranostics. Additionally, transformation of the immunologically cold tumor microenvironment into hot is of great importance for obtaining high antitumor responses for most immunotherapies. However, as far as it is known, there are nearly no studies on self-assembling peptides reported to be able to convert cold to hot tumors. Herein, a self-assembling peptide-based cancer theranostic agent (named DBT-2FFGYSA) is designed and synthesized, which can target tumor-specific transmembrane Eph receptor A2 (EphA2) receptors selectively and make the receptors form large aggregates. Such aggregate formation promotes the cross-phosphorylations among EphA2 receptors, leading to signal transduction of antitumor pathway. As a consequence, DBT-2FFGYSA can not only visualize EphA2 receptors in a fluorescence turn-on manner, but also specifically suppress the EphA2 receptor-overexpressed cancer cell proliferation and tumor growth. What is more, DBT-2FFGYSA also serves as an effective agent to convert immunologically cold tumors to hot by inducing the immunogenic cell death of EphA2 receptor-overexpressed cancer cells and recruiting massive tumor-infiltrating T cells. This study, thus, introduces a new category of agents capable of converting cold to hot tumors by pure supramolecular self-assembly without any aid of known anticancer drugs.

Targeting Hypoxic Tumors with Hybrid Nanobullets for Oxygen-Independent Synergistic Photothermal and Thermodynamic Therapy

Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment. Herein, we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the "precise strike" of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid (HA) and hypoxia-dependent factor carbonic anhydrase IX (CA IX)-inhibitor acetazolamide (AZ). The core of nanobullets is the special zinc (II) phthalocyanine aggregates (ZPA) which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy (PTT), along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy (TDT). The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional (reactive oxygen species (ROS)-mediated) cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.

Peptide Assemblies Mimicking Chaperones for Protein Trafficking

Although peptide assemblies have been explored extensively, the self-assembly of negatively charged peptides (NCPs) received little attention. Stimulated by the fact that acidic stretch is a common feature in the intrinsically disordered regions of histone chaperones, we explored the use of the assemblies of NCPs for trafficking histone proteins. Our results show that the peptides that contain glutamic acid (E)-repeat, at neutral or basic pH, self-assemble to form micelles in solution. Circular dichroism indicates that increasing pH favored the peptides to populate more in disordered and α helix conformations. Being innocuous to cells, the assemblies of these NCPs traffic histone 2B (H2B) to mitochondria. Structure-activity study indicates that self-assembly, proper stereochemistry, and acidic repeats are necessary for trafficking H2B. This work, as the first example of peptide assemblies for protein trafficking, illustrates a supramolecular approach for controlling cellular processes and provides insights for mimicking chaperones and controlling protein-protein interactions.

Designing Hypoxia-Responsive Nanotheranostic Agents for Tumor Imaging and Therapy

Hypoxia, a common feature of most solid tumors, plays an important role in tumor proliferation, metastasis, and invasion, leading to drug, radiation, and photodynamic therapy resistance, and resulting in a sharp reduction in the disease-free survival rate of tumor patients. The lack of sufficient blood supply to the interior regions of tumors hinders the delivery of traditional drugs and contrast agents, interfering with their accumulation in the hypoxic region, and preventing efficient theranostics. Thus, there is a need for the fabrication of novel tumor theranostic agents that overcome these obstacles. Reports, in recent years, of hypoxia-responsive nanomaterials may provide with such means. In this review, a comprehensive description of the physicochemical and biological characteristics of hypoxic tumor tissues is provided, the principles of designing the hypoxia-responsive tumor theranostic agents are discussed, and the recent research into hypoxia-triggered nanomaterials is examined. Additionally, other hypoxia-associated responsive strategies, the current limitations, and future prospects for hypoxia-responsive nanotheranostic agents in tumor treatment are discussed.

Pathological environment directed in situ peptidic supramolecular assemblies for nanomedicines

Peptidic self-assembly provides a powerful method to build biomedical materials with integrated functions. In particular, pathological environment instructed peptidic supramolecular have gained great progress in treating various diseases. Typically, certain pathology related factors convert hydrophilic precursors to corresponding more hydrophobic motifs to assemble into supramolecular structures. Herein, we would like to review the recent progress of nanomedicines based on the development of instructed self-assembly against several specific disease models. Firstly we introduce the cancer instructed self-assembly. These assemblies have exhibited great inhibition efficacy, as well as enhanced imaging contrast, against cancer models both in vitro and in vivo. Then we discuss the infection instructed peptidic self-assembly. A number of different molecular designs have demonstrated the potential antibacterial application with satisfied efficiency for peptidic supramolecular assemblies. Further, we discuss the application of instructed peptidic self-assembly for other diseases including neurodegenerative disease and vaccine. The assemblies have succeeded in down-regulating abnormal Aβ aggregates and immunotherapy. In summary, the self-assembly precursors are typical two-component molecules with (1) a self-assembling motif and (2) a cleavable trigger responsive to the pathological environment. Upon cleavage, the self-assembly occurs selectively in pathological loci whose targeting capability is independent from active targeting. Bearing the novel targeting regime, we envision that the pathological conditions instructed peptidic self-assembly will lead a paradigm shift on biomedical materials.

Multifunctional biomolecule nanostructures for cancer therapy

Biomolecule-based nanostructures are inherently multifunctional and harbour diverse biological activities, which can be explored for cancer nanomedicine. The supramolecular properties of biomolecules can be precisely programmed for the design of smart drug delivery vehicles, enabling efficient transport in vivo, targeted drug delivery and combinatorial therapy within a single design. In this Review, we discuss biomolecule-based nanostructures, including polysaccharides, nucleic acids, peptides and proteins, and highlight their enormous design space for multifunctional nanomedicines. We identify key challenges in cancer nanomedicine that can be addressed by biomolecule-based nanostructures and survey the distinct biological activities, programmability and in vivo behaviour of biomolecule-based nanostructures. Finally, we discuss challenges in the rational design, characterization and fabrication of biomolecule-based nanostructures, and identify obstacles that need to be overcome to enable clinical translation.

Enzyme-instructed morphological transition of the supramolecular assemblies of branched peptides

Here, we report the use of an enzymatic reaction to cleave the branch off branched peptides for inducing the morphological transition of the assemblies of the peptides. The attachment of DEDDDLLI sequences to the ε-amine of the lysine residue of a tetrapeptide produces branched peptides that form micelles. Upon the proteolytic cleavage of the branch, catalyzed by proteinase K, the micelles turn into nanofibers. We also found that the acetylation of the N-terminal of the branch increased the stability of the branched peptides. Moreover, these branched peptides facilitate the delivery of the proteins into cells. This work contributes insights for the development of peptide supramolecular assemblies via enzymatic noncovalent synthesis in cellular environment.

Self-Delivery Photodynamic Nanoinhibitors for Tumor Targeted Therapy and Metastasis Inhibition

Simultaneous inhibitions of primary tumor growth and distant metastasis are very critical for cancer patients to improve their survival and cure rates. Although photodynamic therapy (PDT) shows great potential for primary tumor treatment, it often exacerbates hypoxia with a reduced therapeutic efficacy and subsequently contributes to carcinoma progression and metastatic dissemination. To solve these issues, self-delivery photodynamic nanoinhibitors (PNI) are developed for tumor targeted therapy and metastasis inhibition. PNI are composed of a carbonic anhydrase inhibitor (CAi), a hydrophilic poly(ethylene glycol) (PEG) linker, and a hydrophobic photosensitizer protoporphyrin IX (PpIX). Such self-delivery design of PNI avoids the premature release and heterogeneous distribution of CAi and PpIX to enhance the availability and synergism. Briefly, the CAi-based nanoinhibitors improve the selectivity of CAi for specific recognition and inhibition of tumor-associated isoform carbonic anhydrase (CA) IX, which would not only facilitate the targeted drug delivery of PNI but also regulate the hypoxia-induced signaling cascade and PDT resistance. Benefiting from the CA IX inhibition and targeted PDT, PNI exhibit a robust inhibitory effect on primary tumor growth and distant metastasis. This targeted self-delivery strategy sheds light on the photosensitizer-based molecular design to overcome the defect of traditional PDT.

Novel multifunctional and multitarget homo- (Fe2) and heterobimetallic [(Fe,M) with M = Re or Mn] sulfonyl hydrazones

The synthesis and characterization of the novel ferrocenyl sulfonyl hydrazide [Fe(η5-C5H5){(η5-C5H4)-S(O)2-NH-NH2}] (2) is reported. Additional studies on its reactivity using acetone or the ferrocenyl-, cyrhetrenyl- or cymantrenyl-aldehydes have allowed us to isolate and characterize [Fe(η5-C5H5){(η5-C5H4)-S(O)2-NH-N[double bond, length as m-dash]CMe2}] (3), the bis(ferrocenyl) derivative [Fe(η5-C5H5){[(η5-C5H4)-S(O)2-NH-N[double bond, length as m-dash]CH-(η5-C5H4)]Fe(η5-C5H5)}] (4) and the heterodimetallic compounds [Fe(η5-C5H5){[(η5-C5H4)-S(O)2-NH-N[double bond, length as m-dash]CH-(η5-C5H4)]M(CO)3}] with M = Re (5a) or Mn (5b). The X-ray crystal structures of compounds 3, 5a and 5b are also reported. A comparative study of their electrochemical and spectroscopic properties is also described. Additional computational calculations based on the DFT methodology have allowed us to elucidate the effect produced by the replacement of the terminal -NH2 (in 2) by the -N[double bond, length as m-dash]CMe2 (in 3) and -N[double bond, length as m-dash]CHR (in 4, 5a and 5b) moieties on the electronic distribution and to explain the differences detected in their electrochemical properties and absorption spectra. In vitro cytotoxicity studies of compounds 2, 4, 5a and 5b on the HCT-116 (colon), MCF7 and MDA-MB231 (breast) cancer cell lines reveal that compound 2 has no significant activity (IC50 > 100 μM), while its derivatives 4, 5a and 5b proved to be active in the three cancer cell lines selected in this study. The growth inhibition potency of compounds 5a and 5b against the triple negative MDA-MB231 breast cancer cell line is similar (or slightly) greater than that of cisplatin. Moreover, compounds 2, 4, 5a and 5b are less toxic than cisplatin in the normal and non-tumoral BJ fibroblasts, and the heterodimetallic complexes 5a and 5b with selective index >2.1 show an outstanding selective toxicity towards the MDA-MB231 cancer cells.

Tumor-Triggered Disassembly of a Multiple-Agent-Therapy Probe for Efficient Cellular Internalization

Integration of multiple agent therapy (MAT) into one probe is promising for improving therapeutic efficiency for cancer treatment. However, MAT probe, if entering the cell as a whole, may not be optimal for each therapeutic agent (with different physicochemical properties), to achieve their best performance, hindering strategy optimization. A peptide-conjugated-AIEgen (FC-PyTPA) is presented: upon loading with siRNA, it self-assembles into FC_siRNA -PyTPA. When approaching the region near tumor cells, FC_siRNA -PyTPA responds to extracellular MMP-2 and is cleaved into FC_siRNA and PyTPA. The former enters cells mainly by macropinocytosis and the latter is internalized into cells mainly through caveolae-mediated endocytosis. This two-part strategy greatly improves the internalization efficiency of each individual therapeutic agent. Inside the cell, self-assembly of nanofiber precursor F, gene interference of C_siRNA , and ROS production of PyTPA are activated to inhibit tumor growth.

Metal ion and light sequentially induced sol-gel-sol transition of a responsive peptide-hydrogel

We developed a new responsive peptide hydrogel FmocFFpSC(oNB)-PEG, which could achieve gel formation induced by calcium ions and sequential dissolution stimulated by light. It provides a potential delivery system for the efficient encapsulation of drugs and their controlled release in a spatial and temporal way.

CAIXplatins: Highly Potent Platinum(IV) Prodrugs Selective Against Carbonic Anhydrase IX for the Treatment of Hypoxic Tumors

Hypoxia and the acidic microenvironment play a vital role in tumor metastasis and angiogenesis, generally compromising the chemotherapeutic efficacy. This provides a tantalizing angle for the design of platinum(IV) prodrugs for the effective and selective killing of solid tumors. Herein, two carbonic anhydrase IX (CAIX)-targeting platinum(IV) prodrugs have been developed, named as CAIXplatins. Based on their strong affinity for and inhibition of CAIX, CAIXplatins can not only overcome hypoxia and the acidic microenvironment, but also inhibit metabolic pathways of hypoxic cancer cells, resulting in a significantly enhanced therapeutic effect on hypoxic MDA-MB-231 tumors both in vitro and in vivo compared with cisplatin/oxaliplatin, accompanied with excellent anti-metastasis and anti-angiogenesis activities. Furthermore, the cancer selectivity indexes of CAIXplatins are 70-90 times higher than those of cisplatin/oxaliplatin with effectively alleviated side-effects.

Charge-reversal surfactant antibiotic material for reducing microbial corrosion in petroleum exploitation and transportation

The corrosions caused by sulfate-reducing bacteria (SRB) are serious problems in petroleum exploitation and transportation, which can lead to safety problems, environmental pollutions, and economic losses. Here, a charge-reversal surfactant antibiotic material N-dodecyl-1-carboxylic acid-1-cyclohexenyl-2-carboxamide (C12N-DCA) is designed and synthesized. C12N-DCA is a negatively charged surfactant, which cannot be adsorbed by soil and rock in a large amount. Therefore, it can reach the "lesion location", with enough concentration. After being hydrolyzed and charge reversed under the acceleration of H2S produced by SRB, C12N-DCA becomes a positively charged surfactant dodecane ammonium salt to kill SRB. Through a simulating experiment, it is found that C12N-DCA can reach the SRB inhibition ratio of almost 100%, and it can reduce iron corrosion by 88%. Such an antibiotic material or its homologs may be added to the chemical flooding fluids, killing SRB during petroleum exploitation and reducing the SRB-induced corrosion in the petroleum exploitation and transportation.

Current developments in nanotechnology for improved cancer treatment, focusing on tumor hypoxia

Hypoxia is a common feature of the tumor microenvironment, which is characterized by tissue oxygen deficiency due to an aggressive proliferation of cancer cells. Hypoxia activates hypoxia-inducible factor-dependent signaling, which in turn regulates metabolic reprogramming, immune suppression, resistance to apoptosis, angiogenesis, metastasis, and invasion to secondary sites. In this review, we provide an overview of the use of nanotechnology to harmonize intra-tumoral oxygen or suppress hypoxia-related signaling for an improved efficacy of cancer treatment. The biological background was followed by conducting a literature review on the (1) nanoparticles responsible for enhancing oxygen levels within the tumor, (2) nanoparticles sensitizing hypoxia, (3) nanoparticles suppressing hypoxia-inducing factor, (4) nanoparticles that relieve tumor hypoxia for enhancement of chemotherapy, photodynamic therapy, and immunotherapy, either individually or in combination. Lastly, the heterogeneity of cancer and limitations of nanotechnology are discussed to facilitate translational therapeutic treatment.

Functional peptide-based drug delivery systems

Peptides are one of the most important functional motifs for constructing smart drug delivery systems (DDSs). Functional peptides can be conjugated with drugs or carriers via covalent bonds, or assembled into DDSs via supramolecular forces, which enables the DDSs to acquire desired functions such as targeting and/or environmental responsiveness. In this mini review, we first introduce the different types of functional peptides that are commonly used for constructing DDSs, and we highlight representative strategies for designing smart DDSs by using functional peptides in the past few years. We also state the challenges of peptide-based DDSs and come up with prospects.

Metal ions modulation of the self-assembly of short peptide conjugated nonsteroidal anti-inflammatory drugs (NSAIDs)

Metal ions are essential components that help maintain the processes of normal life, and they can be used to fabricate self-assembled building blocks for peptide derivatives, proteins and nucleic acids. Here, we have developed a novel strategy to construct supramolecular hydrogels modulated using metal cations. Upon introducing a variety of metal ions into aqueous solutions of a gelator (naproxen-FF), including a nonsteroidal anti-inflammatory drug (NSAID) and dipeptide, we obtain stable hydrogels under neutral or alkaline conditions. It is found that these hydrogels with three-dimensional nanofiber networks exhibit excellent mechanical properties and thixotropy, as well as superb responsivity to multiple metal ions. Due to the significance of potassium ions in biological processes, the K-triggered hydrogel has been chosen as a model, and its self-assembly mechanism has been explored via various spectral analysis processes. In addition, the self-assembly performances of peptides are significantly affected by the chemical structures of the gelator molecules. This work provides deep insight into the aggregation mechanism of dipeptide-conjugating drug molecules through introducing a variety of metal ions, laying the foundation for further biological applications.

Comprehensive Analysis for Identifying Diagnostic and Prognostic Biomarkers in Colon Adenocarcinoma

Colon adenocarcinoma (COAD) is a common noncutaneous carcinoma worldwide with high morbidity and mortality. Effective prevention methods are far from being met. Both diagnostic and prognostic models that can precisely and accurately predict the status and survival time of COAD are urgently needed. In the field of COAD, there have been limited studies on molecular biomarkers that can predict disease status and prognosis. Hence, an important task is to identify these biomarkers. We aimed to identify important risk genes that have the ability not only to diagnose tumors but also to predict overall survival. A comprehensive analysis was performed in this study. Finally, carbonic anhydrase 1 (CA1) and CA4 were identified as potential biomarkers due to their predictive roles in diagnosis and prognosis, and the results were further confirmed by a series of analyses. Overall, these findings are of great importance and may facilitate individualized treatment in diagnosis and prognosis.

A Validation Study of a Multiple Reaction Monitoring-Based Proteomic Assay to Diagnose Breast Cancer

Purpose

Currently, the standard screening tool for breast cancer is screening mammography. There have been many efforts to develop a blood-based diagnostic assay for breast cancer diagnosis; however, none have been approved for clinical use at this time. The purpose of this study was to determine the accuracy of a novel blood-based proteomic test for aiding breast cancer diagnosis in a relatively large cohort of cancer patients.

Methods

A blood-based test using multiple reaction monitoring (MRM) measured by mass spectrometry to quantify 3 peptides (apolipoprotein C-1, carbonic anhydrase 1, and neural cell adhesion molecule L1-like protein) present in human plasma was investigated. A total of 1,129 blood samples from 575 breast cancer patients, 454 healthy controls, and 100 patients with other malignancies were used to verify and optimize the assay.

Results

The diagnostic sensitivity, specificity, and accuracy of the MRM-based proteomic assay were 71.6%, 85.3%, and 77%, respectively; the area under the receiver operating characteristic curve was 0.8323. The proteomic assay did not demonstrate diagnostic accuracy in patients with other types of malignancies including thyroid, pancreatic, lung, and colon cancers. The diagnostic performance of the proteomic assay was not associated with the timing of blood sampling before or after anesthesia.

Conclusion

The data demonstrated that an MRM-based proteomic assay that measures plasma levels of three specific peptides can be a useful tool for breast cancer screening and its accuracy is cancer-type specific.