Bispyrene-Based Self-Assembled Nanomaterials: In Vivo Self-Assembly, Transformation, and Biomedical Effects

Peptide-based fluorescent probes for the diagnosis of tumor and image-guided surgery

Fluorescent contrast agents are instrumental in amplifying signals, thereby enhancing the sensitivity and accuracy of live optical imaging. However, a significant proportion of traditional fluorescent contrast agents exhibit drawbacks such as short half-life, suboptimal biocompatibility, and inadequate tumor targeting, all of which impede effective imaging guidance. Peptides, derived from natural structures, offer a flexible modular design that can be precisely engineered and adjusted using synthetic methods to achieve specific biological activity and pharmacokinetic properties. They bind with designated receptors to exert their effects, demonstrating high specificity. The development of fluorescent probes based on peptides significantly overcomes the limitations of conventional contrast agents, offering superior performance. This article provides a comprehensive review of three strategies for constructing peptide-based fluorescent probes, delving into their distinct design concepts, mechanisms of action, and innovative aspects. It also highlights the potential applications of peptide-based fluorescent probes in tumor diagnosis and image-guided surgery, offering insights into their future clinical transformation.

Programming two-component peptide self-assembly by tuning the hydrophobic linker

Molecular self-assembly enables the formation of intricate networks through non-covalent interactions, serving as a key strategy for constructing structures ranging from molecules to macroscopic forms. While zero-dimensional and one-dimensional nanostructures have been widely achieved, two-dimensional nanostrip structures present unique advantages in biomedical and other applications due to their high surface area and potential for functionalization. However, their efficient design and precise regulation remain challenging. This study systematically explores how different hydrophobic amino acid linkers impact the microscopic morphology in two-component co-assembly systems with strong electrostatic interactions. The introduction of the AA linker resulted in distinctive 2D nanostrips, which stacked to form bilayer sheets, whereas VV, LL, and NleNle linkers formed one-dimensional fibers. In contrast, GG and PP linkers did not produce stable aggregates. Our findings highlight the role of intermolecular interactions in the development of 2D assemblies, providing new insights into the design and application of 2D materials.

Chondroitin sulfate-based dissolvable microneedles loaded with NIR-II photothermal and natural anticancer agents for synergistic melanoma therapy

Melanoma is characterized by its aggressiveness, high metastatic potential, and numerous mutations, which limit the effectiveness of current treatments. To address this issue, we developed a dissolvable microneedle (MN) system composed of poly(2-ethyl-2-oxazoline) (PEtOz) and chondroitin sulfate (CS). This MN system was loaded with liposomes containing both a NIR-II photothermal small molecule (IRLy) and the natural anticancer agent Gambogic acid (GA), forming Lip(IRLy + GA) MNs. The integration of the dissolvable microneedle with drug-loaded liposomes aligns with the mechanical properties and skin penetration efficiency required for effective drug delivery. It enables minimally invasive, painless, and precise administration of IRLy and GA. Under NIR-II 1064 nm laser irradiation, Lip(IRLy + GA) effectively inhibited melanoma by disrupting blood vessels, inducing apoptosis, and altering mitochondrial membrane potential. In a subcutaneous melanoma (A375) model in nude mice, the combination of Lip(IRLy + GA) and laser treatment demonstrated a synergistic effect, enhancing both photothermal and chemotherapeutic outcomes. This research presents a promising strategy that combines NIR-II photothermal agents with natural chemotherapeutic drugs and highlights the potential of microneedles in combination therapies for superficial skin cancers like melanoma.

Activatable peptide-AIEgen conjugates for cancer imaging

Aggregation-induced emission luminogens (AIEgens) have undergone significant development over the past decade, making substantial and profound contributions to a diverse range of research fields, prominently including cancer/disease diagnosis and therapy. Through the covalent conjugation of AIEgens with functional peptides, the resultant peptide-AIEgen conjugates possess not only the excellent biocompatibility characteristics, along with low systemic toxicity and negligible immunogenicity of peptides, but also the remarkable fluorescence properties of AIEgens. This "win-win" integration has significantly propelled the applications of peptide-AIEgen conjugates, particularly within the domain of cancer imaging. Three principal types of peptide-AIEgen conjugates, namely, tumor-targeting, tumor biomarker-responsive, and biomarker-responsive self-assembling peptide-AIEgen conjugates, are commonly devised. These conjugates confer enhanced targeting capabilities and selectivity towards tumors, thereby facilitating "smart" and precise tumor imaging with high signal-to-background ratios. In light of the crucial significance of peptide-AIEgen conjugates in tumor imaging and the recent inspiring breakthroughs that have not been encompassed in previous reviews, we present this review. We highlight the activatable peptide-AIEgen conjugates developed for tumor imaging over the past three years (from 2022 to the present). Particular attention is directed towards their design rationales, operational mechanisms, and imaging performance. Finally, prospective opportunities within this field are also reasonably deliberated.

De novo design of self-assembling peptides with antimicrobial activity guided by deep learning

Bioinspired materials based on self-assembling peptides are promising for tackling various challenges in biomedical engineering. While contemporary data-driven approaches have led to the discovery of self-assembling peptides with various structures and properties, predicting the functionalities of these materials is still challenging. Here we describe the deep learning-guided de novo design of antimicrobial materials based on self-assembling peptides targeting bacterial membranes to address the emerging problem of bacterial drug resistance. Our approach integrates non-natural amino acids for enhanced peptide self-assembly and effectively predicts the functional activity of the self-assembling peptide materials with minimal experimental annotation. The designed self-assembling peptide leader displays excellent in vivo therapeutic efficacy against intestinal bacterial infection in mice. Moreover, it exhibits an enhanced biofilm eradication capability and does not induce acquired drug resistance. Mechanistic studies reveal that the designed peptide can self-assemble on bacterial membranes to form nanofibrous structures for killing multidrug-resistant bacteria. This work thus provides a strategy to discover functional peptide materials by customized design.

Combating Antibiotic-Resistant Bacterial Infection Using Coassembled Dimeric Antimicrobial Peptide-Based Nanofibers

The emergence of multidrug-resistant (MDR) pathogens, coupled with the limited effectiveness of existing antibiotics in eradicating biofilms, presents a significant threat to global health care. This critical situation underscores the urgent need for the discovery and development of antimicrobial agents. Recently, peptide-derived antimicrobial nanomaterials have shown promise in combating such infections. Amino acid noncovalent forces, notably π-π stacking and electrostatic interactions, remain underutilized for guiding the coassembly of peptides into bacteriostatic nanomaterials. Thus, we constructed a dimeric nanopeptide system using the disulfide bonds of cysteine. The self-assembly of dimeric peptides into nanofibers was realized by the interaction of π-π aromatic amino acids (Trp, Phe, and Pyr) and the electrostatic attraction between oppositely charged amino acids (Asp and Arg). The optimal dimeric peptide 2D2W exhibits potent antibacterial activity against resistant bacteria and is nontoxic. Mechanistically, 2D2W penetrated the outer membrane after electrostatic adsorption, resulting in plasma membrane depolarization, homeostatic disruption, and ultimately bacterial death. In a mouse model of peritonitis, 2D2W demonstrated efficacy in the in vivo treatment of bacterial infections. In conclusion, the design of dimeric nanopeptides co-driven by intermolecular forces provides a promising avenue for the development of high-performance antimicrobial nanomaterials. These advances may also facilitate the application and advancement of peptide-based bacteriostatic agents in clinical practice.

Intracellularly manipulable aggregation of the aggregation-induced emission luminogens

Biophotonics has seen significant advancements with the development of optical imaging techniques facilitating the noninvasive detection of biologically relevant species. Aggregation-induced emission (AIE) materials have emerged as a novel class of luminogens exhibiting enhanced luminescence or photodynamic efficiency in the aggregated state, making them ideal for biomedical applications. The intracellularly controlled aggregation of aggregate-induced emission luminogens (AIEgens) enables high-resolution imaging of intracellular targets and diagnosis of related diseases, and enables disease therapy by exploiting the novel properties of aggregates. This review provides an in-depth analysis of the strategies employed to modulate the aggregation of AIEgens, focusing on the importance of molecular modifications to improve hydrophilicity and achieve precise control over the intercellular aggregation of AIEgens. Furthermore, the representative applications of AIEgens in bioimaging, such as enzyme activity monitoring, protein tracking, organelle function monitoring, and in vivo tumor-specific therapeutics, are reviewed. Additionally, we outline the challenges and future opportunities for AIE research, emphasizing the importance of the strategies for realizing the precisely controllable aggregation of AIEgens inside cells and the need for extending AIEgens' absorption and emission wavelengths. This review aims to elucidate the rational development of responsive AIEgens for advanced biomedical applications.

Nanomaterial-assisted delivery of CpG oligodeoxynucleotides for boosting cancer immunotherapy

Cancer immunotherapy aims to improve immunity to not only eliminate the primary tumor but also inhibit metastasis and recurrence. It is considered an extremely promising therapeutic approach that breaks free from the traditional paradigm of oncological treatment. As the medical community learns more about the immune system's mechanisms that "turn off the brake" and "step on the throttle", there is increasingly successful research on immunomodulators. However, there are still more restrictions than countermeasures with immunotherapy related to immunomodulators, such as low responsiveness and immune-related adverse events that cause multiple adverse reactions. Therefore, medical experts and materials scientists attempted to the efficacy of immunomodulatory treatments through various methods, especially nanomaterial-assisted strategies. CpG oligodeoxynucleotides (CpG) not only act as an adjuvant to promote immune responses, but also induce autophagy. In this review, the enhancement of immunotherapy using nanomaterial-based CpG formulations is systematically elaborated, with a focus on the delivery, protection, synergistic promotion of CpG efficacy by nanomaterials, and selection of the timing of treatment. In addition, we also discuss and prospect the existing problems and future directions of research on nanomaterials in auxiliary CpG therapy.

Deformable nanocarriers for enhanced drug delivery and cancer therapy

Recently, the field of nanomedicine has witnessed substantial advancements in the development of nanocarriers for targeted drug delivery, emerges as promising platforms to enhance therapeutic efficacy and minimize adverse effects associated with conventional chemotherapy. Notably, deformable nanocarriers have garnered considerable attention due to their unique capabilities of size changeable, tumor-specific aggregation, stimuli-triggered disintegration, and morphological transformations. These deformable nanocarriers present significant opportunities for revolutionizing drug delivery strategies, by responding to specific stimuli or environmental cues, enabling achieved various functions at the tumor site, including size-shrinkage nanocarriers enhance drug penetration, aggregative nanocarriers enhance retention effect, disintegrating nanocarriers enable controlled drug release, and shape-changing nanocarriers improve cellular uptake, allowing for personalized treatment approaches and combination therapies. This review provides an overview of recent developments and applications of deformable nanocarriers for enhancing tumor therapy, underscores the diverse design strategies employed to create deformable nanocarriers and elucidates their remarkable potential in targeted tumor therapy.

In Vivo Self-Sorting of Peptides via In Situ Assembly Evolution

Despite significant progress achieved in artificial self-sorting in solution, operating self-sorting in the body remains a considerable challenge. Here, we report an in vivo self-sorting peptide system via an in situ assembly evolution for combined cancer therapy. The peptide E3C16-SS-EIY consists of two disulfide-connected segments, E3C16SH and SHEIY, capable of independent assembly into twisted or flat nanoribbons. While E3C16-SS-EIY assembles into nanorods, exposure to glutathione (GSH) leads to the conversion of the peptide into E3C16SH and SHEIY, thus promoting in situ evolution from the nanorods into self-sorted nanoribbons. Furthermore, incorporation of two ligand moieties targeting antiapoptotic protein XIAP and organellar endoplasmic reticulum (ER) into the self-sorted nanoribbons allows for simultaneous inhibition of XIAP and accumulation surrounding ER. This leads to the cytotoxicity toward the cancer cells with elevated GSH levels, through activating caspase-dependent apoptosis and inducing ER dysfunction. In vivo self-sorting of E3C16-SS-EIY decorated with ligand moieties is thoroughly validated by tissue studies. Tumor-bearing mouse experiments confirm the therapeutic efficacy of the self-sorted assemblies for inhibiting tumor growth, with excellent biosafety. Our findings demonstrate an efficient approach to develop in vivo self-sorting systems and thereby facilitating in situ formulation of biomedical agents.

Targeted drug-loaded peptides induce tumor cell apoptosis and immunomodulation to increase antitumor efficacy

Immunotherapy is an emerging approach for the treatment of solid tumors. Although chemotherapy is generally considered immunosuppressive, specific chemotherapeutic agents can induce tumor immunity. In this study, we developed a targeted, acid-sensitive peptide nanoparticle (DT/Pep1) to deliver doxorubicin (DOX) and triptolide (TPL) to breast cancer cells via the enhanced permeability and retention (EPR) effect and the breast cancer-targeting effect of peptide D8. Compared with administration of the free drugs, treatment with the DT/Pep1 system increased the accumulation of DOX and TPL at the tumor site and achieved deeper penetration into the tumor tissue. In an acidic environment, DT/Pep1 transformed from spherical nanoparticles to aggregates with a high aspect ratio, which successfully extended the retention of the drugs in the tumor cells and bolstered the anticancer effect. In both in vivo and in vitro experiments, DT/Pep1 effectively blocked the cell cycle and induced apoptosis. Importantly, the DT/Pep1 system efficiently suppressed tumor development in mice bearing 4T1 tumors while simultaneously promoting immune system activation. Thus, the results of this study provide a system for breast cancer therapy and offer a novel and promising platform for peptide nanocarrier-based drug delivery.

Long-term combined blockade of CXCR4 and PD-L1 with in vivo reassembly for intensive tumor interference

Negative immunoregulatory signal (PD-L1, CXCR4, et al.) and weak immunogenicity elicited immune system failing to detect and destroy cancerous cells. CXCR4 blockade promoted T cell tumor infiltration and increased tumor sensitivity to anti-PD-L1 therapy. Here, pH-responsive reassembled nanomaterials were constructed with anti-PD-L1 peptide and CXCR4 antagonists grafting (APAB), synergized with photothermal therapy for melanoma and breast tumor interference. The self-assembled APAB nanoparticles accumulated in the tumor and rapidly transformed into nanofibers in response to the acidic tumor microenvironment, leading to the exposure of grafted therapeutic agents. APAB enabling to reassemble around tumor cells and remained stable for over 96 h due to the aggregation induced retention (AIR) effect, led to long-term efficiently combined PD-L1 and CXCR4 blockade. Photothermal efficiency (ICG) induced immunogenic cell death (ICD) of tumor cells so as to effectively improve the immunogenicity. The combined therapy (ICG@APAB) could effectively inhibit the growth of primary tumor (∼83.52%) and distant tumor (∼76.24%) in melanoma-bearing mice, and significantly (p < 0.05) prolong the survival time over 42 days. The inhibition assay on tumor metastasis in 4 T1 model mice exhibited ICG@APAB almostly suppressed the occurrence of lung metastases and the expression levels of CD31, MMP-9 and VEGF in tumor decreased by 82.26%, 90.45% and 41.54%, respectively. The in vivo reassembly strategy will offer novel perspectives benefical future immunotherapies and push development of combined therapeutics into clinical settings.

Antimicrobial therapy based on self-assembling peptides

The emergence of drug-resistant microorganisms has threatened global health, and microbial infections have severely limited the use of medical materials. For example, the attachment and colonization of pathogenic bacteria to medical implant materials can lead to wound infections, inflammation and complications, as well as implant failure, shortening their lifespan and even resulting in patient death. In the era of antibiotic resistance, antimicrobial drug discovery needs to prioritize unconventional therapies that act on new targets or adopt new mechanisms. In this regard, supramolecular antimicrobial peptides have emerged as attractive therapeutic platforms, both as bactericides for combination antibiotics and as delivery vehicles. By taking advantage of their programmable intermolecular and intramolecular interactions, peptides can be modified to form higher-order structures (including nanofibers and nanoparticles) with unique functionality. This paper begins with an analysis of the relationship between peptide self-assembly and antimicrobial activity, describes in detail the research and development of various self-assembled antimicrobial peptides in recent years, and finally explores different combinatorial strategies for self-assembling antimicrobial peptides.

Advances in self-assembled nanotechnology in tumor therapy

The emergence of nanotechnology has opened up a new way for tumor therapy. Among them, self-assembled nanotechnology has received extensive attention in medicine due to its simple preparation process, high drug-loading capacity, low toxicity, and low cost. This review mainly summarizes the preparation methods of self-assembled nano-delivery systems, as well as the self-assembled mechanism of carrier-free nanomedicine, polymer-carried nanomedicine, polypeptide, and metal drugs, and their applications in tumor therapy. In addition, we discuss the advantages and disadvantages, future challenges, and opportunities of these self-assembled nanomedicines, which provide important references for the development and application of self-assembled nanotechnology in the field of medical therapy.

Cell Membrane as A Promising Therapeutic Target: From Materials Design to Biomedical Applications

The cell membrane is a crucial component of cells, protecting their integrity and stability while facilitating signal transduction and information exchange. Therefore, disrupting its structure or impairing its functions can potentially cause irreversible cell damage. Presently, the tumor cell membrane is recognized as a promising therapeutic target for various treatment methods. Given the extensive research focused on cell membranes, it is both necessary and timely to discuss these developments, from materials design to specific biomedical applications. This review covers treatments based on functional materials targeting the cell membrane, ranging from well-known membrane-anchoring photodynamic therapy to recent lysosome-targeting chimaeras for protein degradation. The diverse therapeutic mechanisms are introduced in the following sections: membrane-anchoring phototherapy, self-assembly on the membrane, in situ biosynthesis on the membrane, and degradation of cell membrane proteins by chimeras. In each section, we outline the conceptual design or general structure derived from numerous studies, emphasizing representative examples to understand advancements and draw inspiration. Finally, we discuss some challenges and future directions in membrane-targeted therapy from our perspective. This review aims to engage multidisciplinary readers and encourage researchers in related fields to advance the fundamental theories and practical applications of membrane-targeting therapeutic agents.

A peptide selectively recognizes Gram-negative bacteria and forms a bacterial extracellular trap (BET) through interfacial self-assembly

An innate immune system intricately leverages unique mechanisms to inhibit colonization of external invasive Bacteria, for example human defensin-6, through responsive encapsulation of bacteria. Infection and accompanying antibiotic resistance stemming from Gram-negative bacteria aggregation represent an emerging public health crisis, which calls for research into novel anti-bacterial therapeutics. Herein, inspired by naturally found host-defense peptides, we design a defensin-like peptide ligand, bacteria extracellular trap (BET) peptide, with modular design composed of targeting, assembly, and hydrophobic motifs with an aggregation-induced emission feature. The ligand specifically recognizes Gram-negative bacteria via targeting cell wall conserved lipopolysaccharides (LPS) and transforms from nanoparticles to nanofibrous networks in situ to trap bacteria and induce aggregation. Importantly, treatment of the BET peptide was found to have an antibacterial effect on the Pseudomonas aeruginosa strain, which is comparable to neomycin. Animal studies further demonstrate its ability to trigger aggregation of bacteria in vivo. This biomimetic self-assembling BET peptide provides a novel approach to fight against pathogenic Gram-negative bacteria.

Self-assembly of peptide nanomaterials at biointerfaces: molecular design and biomedical applications

Self-assembly is an important strategy for constructing ordered structures and complex functions in nature. Based on this, people can imitate nature and artificially construct functional materials with novel structures through the supermolecular self-assembly pathway of biological interfaces. Among the many assembly units, peptide molecular self-assembly has received widespread attention in recent years. In this review, we introduce the interactions (hydrophobic interaction, hydrogen bond, and electrostatic interaction) between peptide nanomaterials and biological interfaces, summarizing the latest advancements in multifunctional self-assembling peptide materials. We systematically demonstrate the assembly mechanisms of peptides at biological interfaces, such as proteins and cell membranes, while highlighting their application potential and challenges in fields like drug delivery, antibacterial strategies, and cancer therapy.

Nanofibers in Organelles: From Structure Design to Biomedical Applications

Nanofibers are one of the most important morphologies of molecular self-assemblies, the formation of which relies on the diverse intermolecular interactions of fibrous-forming units. In the past decade, rapid advances have been made in the biomedical application of nanofibers, such as bioimaging and tumor treatment. An important topic to be focused on is not only the nanofiber formation mechanism but also where it forms, because different destinations could have different influences on cells and its formation could be triggered by unique stimuli in organelles. It is therefore necessary and timely to summarize the nanofibers assembled in organelles. This minireview discusses the formation mechanism, triggering strategies, and biomedical applications of nanofibers, which may facilitate the rational design of nanofibers, improve our understanding of the relationship between nanofiber properties and organelle characteristics, allow a comprehensive recognition of organelles affected by materials, and enhance the therapeutic efficiency of nanofibers.

Bioactive peptides: an alternative therapeutic approach for cancer management

Cancer is still considered a lethal disease worldwide and the patients' quality of life is affected by major side effects of the treatments including post-surgery complications, chemo-, and radiation therapy. Recently, new therapeutic approaches were considered globally for increasing conventional cancer therapy efficacy and decreasing the adverse effects. Bioactive peptides obtained from plant and animal sources have drawn increased attention because of their potential as complementary therapy. This review presents a contemporary examination of bioactive peptides derived from natural origins with demonstrated anticancer, ant invasion, and immunomodulation properties. For example, peptides derived from common beans, chickpeas, wheat germ, and mung beans exhibited antiproliferative and toxic effects on cancer cells, favoring cell cycle arrest and apoptosis. On the other hand, peptides from marine sources showed the potential for inhibiting tumor growth and metastasis. In this review we will discuss these data highlighting the potential befits of these approaches and the need of further investigations to fully characterize their potential in clinics.

An In Vivo Self-Assembled Bispecific Nanoblocker for Enhancing Tumor Immunotherapy

Anti-PD-L1 monoclonal antibody has achieved substantial success in tumor immunotherapy by T-cells activation. However, the excessive accumulation of extracellular matrix components induced by unsatisfactory T-cells infiltration and poor tumor penetration of antibodies make it challenging to realize efficient tumor immunotherapy. Herein, a peptide-based bispecific nanoblocker (BNB) strategy is reported for in situ construction of CXCR4/PD-L1 targeted nanoclusters on the surface of tumor cells that are capable of boosting T-cells infiltration through CXCR4 blockage and enhancing T-cells activation by PD-L1 occupancy, ultimately realizing high-performance tumor immunotherapy. Briefly, the BNB strategy selectively recognizes and bonds CXCR4/PD-L1 with deep tumor penetration, which rapidly self-assembles into nanoclusters on the surface of tumor cells. Compared to the traditional bispecific antibody, BNB exhibits an intriguing metabolic behavior, that is, the elimination half-life (t1/2 ) of BNB in the tumor is 69.3 h which is ≈50 times longer than that in the plasma (1.4 h). The higher tumor accumulation and rapid systemic clearance overcome potential systemic side effects. Moreover, the solid tumor stress generated by excessive extracellular matrix components is substantially reduced to 44%, which promotes T-cells infiltration and activation for immunotherapy efficacy. Finally, these findings substantially strengthen and extend clinical applications of PD-1/PD-L1 immunotherapy.

Peptides Targeting HER2-Positive Breast Cancer Cells and Applications in Tumor Imaging and Delivery of Chemotherapeutics

Breast cancer represents the most common cancer type and one of the major leading causes of death in the female worldwide population. Overexpression of HER2, a transmembrane glycoprotein related to the epidermal growth factor receptor, results in a biologically and clinically aggressive breast cancer subtype. It is also the primary driver for tumor detection and progression and, in addition to being an important prognostic factor in women diagnosed with breast cancer, HER2 is a widely known therapeutic target for drug development. The aim of this review is to provide an updated overview of the main approaches for the diagnosis and treatment of HER2-positive breast cancer proposed in the literature over the past decade. We focused on the different targeting strategies involving antibodies and peptides that have been explored with their relative outcomes and current limitations that need to be improved. The review also encompasses a discussion on targeted peptides acting as probes for molecular imaging. By using different types of HER2-targeting strategies, nanotechnology promises to overcome some of the current clinical challenges by developing novel HER2-guided nanosystems suitable as powerful tools in breast cancer imaging, targeting, and therapy.

Coordination-Driven Self-Assembly of Biomedicine to Enhance Photodynamic Therapy by Inhibiting Proteasome and Bcl-2

Tumor cells resist oxidative damage and apoptosis by activating defense mechanisms. Herein, a self-delivery biomedicine (designated as BSC) is developed by the self-assembly of Bortezomib (BTZ), Sabutoclax (Sab) and Chlorin e6 (Ce6). Interestingly, BTZ can be coordinated with Sab to promote the assembly of uniform ternary biomedicine through non-covalent intermolecular interactions. Moreover, BTZ as a proteasome inhibitor can prevent tumor cells from scavenging damaged proteins to reduce their oxidative resistance. Sab can downregulate B-cell lymphoma 2 (Bcl-2) to decrease the antiapoptotic protein. Both the proteasome and Bcl-2 inhibitions contribute to increasing cell apoptosis and amplifying photodynamic therapy (PDT) efficacy of Ce6. Encouragingly, carrier-free BSC receives all biological activities of these assembly elements, including photodynamic performance as well as inhibitory capabilities of proteasome and Bcl-2. Besides, BSC has a preferable cellular uptake ability and tumor retention property, which increase the drug delivery efficiency and bioavailability. In vitro and in vivo research demonstrate the superior PDT efficiency of BSC by proteasome and Bcl-2 inhibitions. Of special note, the coordination-driven self-assembly of BSC is pH-responsive, which can be disassembled for controlled drug release upon tumor acidic microenvironment. This study will expand the applicability of self-delivery nanomedicine with sophisticated mechanisms for tumor treatment.

Transformable nano-antibiotics for mechanotherapy and immune activation against drug-resistant Gram-negative bacteria

The dearth of antibiotic candidates against Gram-negative bacteria and the rise of antibiotic resistance create a global health concern. The challenge lies in the unique Gram-negative bacterial outer membrane that provides the impermeable barrier for antibiotics and sequesters antigen presentation. We designed a transformable nano-antibiotics (TNA) that can transform from nontoxic nanoparticles to bactericidal nanofibrils with reasonable rigidity (Young's modulus, 21.6 ± 5.9 MPa) after targeting β-barrel assembly machine A (BamA) and lipid polysaccharides (LPSs) of Gram-negative bacteria. After morphological transformation, the TNA can penetrate and damage the bacterial envelope, disrupt electron transport and multiple conserved biosynthetic and metabolic pathways, burst bacterial antigen release from the outer membrane, and subsequently activate the innate and adaptive immunity. TNA kills Gram-negative bacteria in vitro and in vivo with undetectable resistance through multiple bactericidal modes of action. TNA treatment-induced vaccination results in rapid and long-lasting immune responses, protecting against lethal reinfections.

Cell membrane-specific self-assembly of peptide nanomedicine induces tumor immunogenic death to enhance cancer therapy

Immunogenic cell death (ICD), as an unusual cell death pattern, mediates cancer cells to release a series of damage-associated molecular patterns (DAMPs), and is widely used in the field of cancer immunotherapy. Injuring the cell membrane can serve as a novel ICD initiation strategy. In this study, a peptide nanomedicine (PNpC) is designed using the fragment CM11 of cecropin, which is effective in disrupting cell membranes because of its α-helical structure. PNpC self-assembles in situ in the presence of high levels of alkaline phosphatase (ALP) on the tumor cell membrane, transforming from nanoparticles to nanofibers, which reduces the cellular internalization of the nanomedicine and increases the interaction between CM11 and tumor cell membranes. Both in vitro and in vivo results indicate that PNpC plays a significant role in killing tumor cells by triggering ICD. The ICD induced by the destruction of the cancer cell membrane is accompanied by the release of DAMPs, which promotes the maturation of DCs and facilitates the presentation of tumor-associated antigens (TAA), resulting in the infiltration of CD8+ T cells. We believe that PNpC can trigger ICD while killing cancer cells, providing a new reference for cancer immunotherapy.

DNA-guided self-assembly in living cells

Self-assembly processes exist widely in life systems and play essential roles in maintaining life activities. It is promising to explore the molecular fundamentals and mechanisms of life systems through artificially constructing self-assembly systems in living cells. As an excellent self-assembly construction material, deoxyribonucleic acid (DNA) has been widely used to achieve the precise construction of self-assembly systems in living cells. This review focuses on the recent progress of DNA-guided intracellular self-assembly. First, the methods of intracellular DNA self-assembly based on the conformational transition of DNA are summarized, including complementary base pairing, the formation of G-quadruplex/i-motif, and the specific recognition of DNA aptamer. Next, The applications of DNA-guided intracellular self-assembly on the detection of intracellular biomolecules and the regulation of cell behaviors are introduced, and the molecular design of DNA in the self-assembly systems is discussed in detail. Ultimately, the challenges and opportunities of DNA-guided intracellular self-assembly are commented.

Microneedle-mediated delivery of Ziconotide-loaded liposomes fused with exosomes for analgesia

Ziconotide (ZIC) is an N-type calcium channel antagonist for treating severe chronic pain that is intolerable, or responds poorly to the administration of other drugs, such as intrathecal morphine and systemic analgesics. As it can only work in the brain and cerebrospinal fluid, intrathecal injection is the only administration route for ZIC. In this study, borneol (BOR)-modified liposomes (LIPs) were fused with exosomes from mesenchymal stem cells (MSCs) and loaded with ZIC to prepare microneedles (MNs) to improve the efficiency of ZIC across the blood-brain barrier. To evaluate local analgesic effects of MNs, the sensitivity of behavioral pain to thermal and mechanical stimuli was tested in animal models of peripheral nerve injury, diabetes-induced neuropathy pain, chemotherapy-induced pain, and ultraviolet-B (UV-B) radiation-induced neurogenic inflammatory pain. BOR-modified LIPs loaded with ZIC were spherical or nearly spherical, with a particle size of about 95 nm and a Zeta potential of -7.8 mV. After fusion with MSC exosomes, the particle sizes of LIPs increased to 175 nm, and their Zeta potential increased to -3.8 mV. The nano-MNs constructed based on BOR-modified LIPs had good mechanical properties and could effectively penetrate the skin to release drugs. The results of analgesic experiments showed that ZIC had a significant analgesic effect in different pain models. In conclusion, the BOR-modified LIP membrane-fused exosome MNs constructed in this study for delivering ZIC provide a safe and effective administration for chronic pain treatment, as well as great potential for clinical application of ZIC.

A tumor-targetable NIR probe with photoaffinity crosslinking characteristics for enhanced imaging-guided cancer phototherapy

Spatiotemporally manipulating the in situ immobilization of theranostic agents within cancer cells to improve their bioavailability is highly significant yet challenging in tumor diagnosis and treatment. Herein, as a proof-of concept, we for the first time report a tumor-targetable near-infrared (NIR) probe DACF with photoaffinity crosslinking characteristics for enhanced tumor imaging and therapeutic applications. This probe possesses great tumor-targeting capability, intensive NIR/photoacoustic (PA) signals, and a predominant photothermal effect, allowing for sensitive imaging and effective photothermal therapy (PTT) of tumors. Most notably, upon 405 nm laser illumination, DACF could be covalently immobilized within tumor cells through a photocrosslinking reaction between photolabile diazirine groups and surrounding biomolecules resulting in enhanced tumor accumulation and prolonged retention simultaneously, which significantly facilitates the imaging and PTT efficacy of tumor in vivo. We therefore believe that our current approach would provide a new insight for achieving precise cancer theranostics.

An in situ protonation-activated supramolecular self-assembly for selective suppression of tumor growth

An in situ supramolecular self-assembly in the subcellular organelles could provide a new strategy to treat diseases. Herein, we report a protonation-activated in situ supramolecular self-assembly system in the lysosomes, which could destabilize the lysosome membrane, resulting in the selective suppression of cancer cells. In this system, pyridyl-functionalized tetraphenylethylene (TPE-Py) was protonated in the lysosomes of A549 lung cancer cells to form octahedron-like structures with cucurbit[8]uril (CB[8]), which impaired the integrity of the lysosome membrane, resulting in selective suppression of cancer cells. Moreover, its anticancer efficiency was also systematically evaluated in vivo, triggering the apoptosis of tumor tissues with ignorable effects on normal organs. Overall, the protonation-activated self-assembly in the lysosomes based on the host-guest complexation would provide a method for novel anti-cancer systems.

In Vivo Anchoring Bis-Pyrene Probe for Molecular Imaging of Early Gastric Cancer by Endoscopic Techniques

With the development of blue laser endoscopy (BLE) technique, it's often used to diagnose early gastric cancer (EGC) by the morphological changes of blood vessels through BLE. However, EGC is still not obvious to identify, resulting in a high rate of missed diagnosis. Molecular imaging can show the changes in early tumors at molecular level, which provides a possibility for diagnosing EGC. Therefore, developing a probe that visually monitors blood vessels of EGC under BLE is particularly necessary. Herein, a bis-pyrene (BP) based nanoprobe (BP-FFVLK-(PEG)-RGD, M1 ) is designed, which can target angiogenesis and self-assemble into fibers in situ, resulting in stable and long-term retention in tumor. Moreover, M1 probe can emit yellow-green fluorescence for imaging under BLE. M1 probe is confirmed to steadily remain in tumor for up to 96 hours in mice transplanted subcutaneously. In addition, the M1 probe is able to target angiogenesis for molecular imaging of isolated human gastric cancer tissue under BLE. Finally, M1 probe i.v. injected into primary gastric cancer model rabbits successfully highlighted the tumor site under BLE, which is confirmed by pathological analysis. It's the first time to develop a probe for diagnosing EGC by visualizing angiogenesis under BLE, showing great clinical significance.

Peptide Supramolecular Assembly-Instructed In Situ Self-Aggregation for Stratified Targeting Sonodynamic Therapy Enhancement of AIE Luminogens

The emergence of aggregation-induced emission luminogens (AIEgens) has attracted substantial scientific attention. However, their antitumor efficacy in photodynamic therapy (PDT) is significantly restricted by the poor water solubility and limited treatment depth. Therefore, a novel AIEgens-involved therapeutic platform with good permeability and bioavailability is urgently required. Herein, supramolecular chemistry is combined with the AIEgen bis-pyrene (BP) to construct a peptide-AIEgen hybrid nanosystem (PAHN). After intravenous injection, the versatile nanoplatform not only improved the hydrophilicity of BP but also achieved stratified targeting from tumor to mitochondrial and induced mitochondrial dysfunction, thus activating caspase-3 upregulation. Then, sonodynamic therapy (SDT), an alternative modality with high tissue penetrability, is performed to evoke reactive oxygen species (ROS) generation for BP. More importantly, since the hydrophilic shell is separated from the nanosystem by the specific cleavage of caspase-3, the resulting decrease in hydrophilicity induced tight self-aggregation of PAHN residues in situ, further allowing more absorbed energy to be used for ROS generation under ultrasound irradiation and enhancing SDT efficacy. Moreover, severe oxidative stress resulting from ROS imbalance in the mitochondria initiates the immunogenic cell death process, thus evoking antitumor immunogenicity. This PAHN provides prospective ideas into AIE-involved antitumor therapy and design of peptide-AIEgens hybrids.

Design of a large Stokes shift ratiometric fluorescent sensor with hypochlorite detection towards the potential application as invisible security ink

Hypochlorite (ClO^-) as a well-known highly reactive oxygen species (ROS), is widely used as preservative and household disinfectant in daily life. Although many fluorescence imaging sensors for ClO^- have been reported, the development of ClO^- ratio fluorescence sensors with large Stokes shift is still quite limited. This sensor shows obvious benefits including minimizing environmental intervention and improving signal-to-noise ratio. In the present project, we report an innovative conjugated pyrene-based system, 1-B, as a chlorine fluorescence sensor. The detector exhibits ratio detection performance, large Stokes and emission shifts. Furthermore, the system has desired sensitivity as well as selectivity for ClO^-. Based on these excellent properties, the sensor 1-B was successfully used as ink to encrypt patterns and anti-counterfeiting information through inkjet printing technology. Compared with the existing probes, the probe shows some superior characteristics, which provides a promising tool for exploring the role of ClO^- response sensor in the field of anti-counterfeiting.

An intelligent peptide recognizes and traps Mycobacterium tuberculosis to inhibit macrophage phagocytosis

Tuberculosis is a major public health concern worldwide, and it is a serious threat to human health for a long period. Macrophage phagocytosis of Mycobacterium tuberculosis (M. tuberculosis) is a crucial process for granuloma formation, which shelters the bacteria and gives them an opportunity for re-activation and spread. Herein, we report an intelligent anti-microbial peptide that can recognize and trap the M. tuberculosis, inhibiting the macrophage phagocytosis process. The peptide (Bis-Pyrene-KLVFF-WHSGTPH, in abbreviation as BFH) first self-assembles into nanoparticles, and then forms nanofibers upon recognizing and binding M. tuberculosis. Subsequently, BFH traps M. tuberculosis by the in situ formed nanofibrous networks and the trapped M. tuberculosis are unable to invade host cells (macrophages). The intelligent anti-microbial peptide can significantly inhibit the phagocytosis of M. tuberculosis by macrophages, thereby providing a favorable theoretical basis for inhibiting the formation of tuberculosis granulomas.

Responsive Peptide Nanofibers with Theranostic and Prognostic Capacity

Photodynamic therapy (PDT) is a highly promising therapeutic modality for cancer treatment. The development of stimuli-responsive photosensitizer nanomaterials overcomes certain limitations in clinical PDT. Herein, we report the rational design of a highly sensitive PEGylated photosensitizer-peptide nanofiber (termed PHHPEG6 NF) that selectively aggregates in the acidic tumor and lysosomal microenvironment. These nanofibers exhibit acid-induced enhanced singlet oxygen generation, cellular uptake, and PDT efficacy in vitro, as well as fast tumor accumulation, long-term tumor imaging capacity and effective PDT in vivo. Moreover, based on the prolonged presence of the fluorescent signal at the tumor site, we demonstrate that PHHPEG6 NFs can also be applied for prognostic monitoring of the efficacy of PDT in vivo, which would potentially guide cancer treatment. Therefore, these multifunctional PHHPEG6 NFs allow control over the entire PDT process, from visualization of photosensitizer accumulation, via actual PDT to the assessment of the efficacy of the treatment.

A pH-Driven Small-Molecule Nanotransformer Hijacks Lysosomes and Overcomes Autophagy-Induced Resistance in Cancer

Smart conversion of supramolecular structures in vivo is an attractive strategy in cancer nanomedicine, which is usually achieved via specific peptide sequences. Here we developed a lysosomal targeting small-molecule conjugate, PBC, which self-assembles into nanoparticles at physiological pH and smartly converts to nanofibrils in lysosomes of tumor cells. Such a transformation mechanically leads to lysosomal dysfunction, autophagy inhibition, and unusual cytoplasmic vacuolation, thus granting PBC a unique anticancer activity as a monotherapy. Importantly, the photo-activated PBC elicits significant phototoxicity to lysosomes and shows enormous advantages in overcoming autophagy-caused treatment resistance frequently occurring in conventional phototherapy. This improved phototherapy achieves a complete cure of oral cancer xenografts upon limited administration. Our work provides a new paradigm for the construction of nonpeptide nanotransformers with biomedical activities.

Programmable design and self assembly of peptide conjugated AIEgens for biomedical applications

Aggregation-induced emission luminogens (AIEgens) possess enhanced fluorescence in highly aggregated states, thus enabling AIEgens as a promising module for highly emissive fluorescence biomaterials. So far, AIEgens-based nanomaterials and their hybrids have been reported for biomedical applications. Benefiting from the intrinsic biocompatibility and biofunction-editing properties of peptides, peptide-AIEgens hybrid biomaterials reveal unlimited possibilities including target capacity, specificity, stimuli-responsiveness, self-assembly, controllable structural transformation, etc.. In the last two decades, peptide-AIEgens hybrid nanomaterials with a unique design concept in aggregated states have achieved various biomedical applications such as biosensing, bioimaging, imaging-guided surgery, drug delivery and therapy. More recently, programmable design of peptide-AIEgens for in situ self-assembly provides a unique strategy for constructing intelligent entities with defined biological functions. In this review, we summarize the basic design principle of programmable peptide-AIEgens, structure-effect relationship and their unusual biomedical effects. Finally, an outlook and perspective toward future challenges and developments of peptide-AIEgens nanomaterials are concluded.

Pyrene-Based AIE Active Materials for Bioimaging and Theranostics Applications

Aggregation-induced emission (AIE) is a unique research topic and property that can lead to a wide range of applications, including cellular imaging, theranostics, analyte quantitation and the specific detection of biologically important species. Towards the development of the AIE-active materials, many aromatic moieties composed of tetraphenylethylene, anthracene, pyrene, etc., have been developed. Among these aromatic moieties, pyrene is an aromatic hydrocarbon with a polycyclic flat structure containing four fused benzene rings to provide an unusual electron delocalization feature that is important in the AIE property. Numerous pyrene-based AIE-active materials have been reported with the AIE property towards sensing, imaging and theranostics applications. Most importantly, these AIE-active pyrene moieties exist as small molecules, Schiff bases, polymers, supramolecules, metal-organic frameworks, etc. This comprehensive review outlines utilizations of AIE-active pyrene-based materials on the imaging and theranostics studies. Moreover, the design and synthesis of these pyrene-based molecules are delivered with discussions on their future scopes.

Smart Peptide Defense Web In Situ Connects for Continuous Interception of IgE against Allergic Rhinitis

Allergic rhinitis (AR) is a chronic inflammatory reaction by immunoglobulin E (IgE) mediators after individual contact with allergens. It affects 10-40% of the world's population and reduces the quality of life. Long-term symptoms of rhinitis can cause inflammation to spread and trigger asthma, which can harm human health. Herein, we develop a Smart PeptIde defeNse (SPIN) web technique, which in situ constructs a peptide web, trapping IgE against AR. Two candidate SPINs, SPIN-1 and SPIN-2, are designed with different IgE-binding sequences. The SPIN-1 or SPIN-2 is able to bind to IgE and transform from nanoparticles into entangled nanofibers. In turn, the web of SPIN-1 or SPIN-2 acts as a long-term trap of IgE to prevent the IgE from binding to mast cells. SPIN-1 or SPIN-2 (10 mg/kg) is able to treat AR model Balb/c mice with high efficiency and reduced symptoms of rhinitis and inflammatory factors, even better than a first-line clinical drug, cetirizine (10 mg/kg). For example, the amount of IL-4 released in the AR group (185.5 ± 6.8 pg/mL) is significantly reduced after the treatment with SPIN-1 (70.4 ± 14.1 pg/mL), SPIN-2 (86.0 ± 9.3 pg/mL), or cetirizine (112.8 ± 19.3 pg/mL). More importantly, compared with the cetirizine group (1 day), the SPIN-1 or SPIN-2 group shows long-term therapeutic effects (1 week). The SPIN web technique shows the great potential for blocking IgE binding to mast cells in vivo, attenuating AR or other allergic reactions.

Strategies of engineering nanomedicines for tumor retention

The retention of therapeutic agents in solid tumors at sufficient concentration and duration is crucial for their antitumor effects. Given the important contribution of nanomedicines to oncology, we herein summarized two major strategies of nanomedicines for tumor retention, such as transformation- and interactions-mediated strategies. The transformation-mediated retention strategy was achieved by enlarging particle size of nanomedicines or modulating the morphology into fibrous structures, while the interactions-mediated retention strategy was accomplished by modulating nanomedicines to promote their interactions with versatile cells or components in tumors. Moreover, we provide some considerations and perspectives of tumor-retaining nanomedicines for effective cancer therapy.

Designing bioresponsive nanomaterials for intracellular self-assembly

Supramolecular assemblies are essential components of living organisms. Cellular scaffolds, such as the cytoskeleton or the cell membrane, are formed via secondary interactions between proteins or lipids and direct biological processes such as metabolism, proliferation and transport. Inspired by nature’s evolution of function through structure formation, a range of synthetic nanomaterials has been developed in the past decade, with the goal of creating non-natural supramolecular assemblies inside living mammalian cells. Given the intricacy of biological pathways and the compartmentalization of the cell, different strategies can be employed to control the assembly formation within the highly crowded, dynamic cellular environment. In this Review, we highlight emerging molecular design concepts aimed at creating precursors that respond to endogenous stimuli to build nanostructures within the cell. We describe the underlying reaction mechanisms that can provide spatial and temporal control over the subcellular formation of synthetic nanostructures. Showcasing recent advances in the development of bioresponsive nanomaterials for intracellular self-assembly, we also discuss their impact on cellular function and the challenges associated with establishing structure–bioactivity relationships, as well as their relevance for the discovery of novel drugs and imaging agents, to address the shortfall of current solutions to pressing health issues.

Creating artificial nanostructures inside living cells requires the careful design of molecules that can transform into active monomers within a complex cellular environment. This Review explores the recent development of bioresponsive precursors for the controlled formation of intracellular supramolecular assemblies.

Self-sorting assembly of artificial building blocks

Self-assembly to build high-level structures, which is ubiquitous in living systems, has captured the imagination of scientists, striving to emulate the intricacy, homogeneity and versatility of the naturally occurring systems, and to pursue a similar level of organization in artificial building blocks. In particular, self-sorting assembly in multicomponent systems, based on the spontaneous recognition and consequent spatial aggregation of the same or interactive building units, is able to realize very complicated assembly behaviours, and usually results in multiple well-ordered products or hierarchical structures in a one-step manner. This highly efficient assembly strategy has attracted tremendous research attention in recent years, and numerous examples have been reported in artificial systems, particularly with supramolecular and polymeric building blocks. In the current review, we summarize the progress in recent years, and classify them into five main categories, based on their working mechanisms or principles. With the review of these strategies, we hope to provide not only some deep insights into this field, but also and more importantly, useful thoughts in the design and fabrication of self-sorting systems in the future.

Bioactive Peptides and Proteins from Wasp Venoms

Wasps, members of the order Hymenoptera, use their venom for predation and defense. Accordingly, their venoms contain various constituents acting on the circulatory, immune and nervous systems. Wasp venom possesses many allergens, enzymes, bioactive peptides, amino acids, biogenic amines, and volatile matters. In particular, some peptides show potent antimicrobial, anti-inflammatory, antitumor, and anticoagulant activity. Additionally, proteinous components from wasp venoms can cause tissue damage or allergic reactions in organisms. These bioactive peptides and proteins involved in wasp predation and defense may be potential sources of lead pharmaceutically active molecules. In this review, we focus on the advances in bioactive peptides and protein from the venom of wasps and their biological effects, as well as the allergic reactions and immunotherapy induced by the wasp venom.

Chemical Design of Activatable Photoacoustic Probes for Precise Biomedical Applications

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

On-demand assembly of polymeric nanoparticles for longer-blood-circulation and disassembly in tumor for boosting sonodynamic therapy

Sonodynamic therapy (SDT) is one of the promising strategies for tumor therapy, but its application is usually hindered by fast clearance in blood-circulation, abnormal tumor microenvironment, and inefficient generation of reactive oxygen species. To solve these problems, we proposed an on-demand assembly-disassembly strategy, where the assembly is favorable for longer-blood-circulation and then the disassembly in tumor is favorable for boosting SDT. Hematoporphyrin monomethyl ether (HMME) as the model of organic sonosensitizers were conjugated with hyaluronic acid (HA). Then HA-HMME was mixed with catalase (CAT) and assembled into polymeric nanoparticles (CAT@HA-HMME NPs) with size of ∼80 nm. CAT@HA-HMME NPs exhibit good biocompatibility and a longer blood half-time (t_1/2 = 4.17 h) which is obviously longer than that (∼0.82 h) of HMME molecules. After HA receptor-mediated endocytosis of cancer cells, CAT@HA-HMME NPs can be cleaved by endogenous hyaluronidase, resulting in the on-demand disassembly in tumor to release HA-HMME molecules and CAT. The CAT catalyzes the endogenous H₂O₂ into O₂ to relieve the hypoxic microenvironment, and the released HA-HMME exhibits a higher ROS generation ability, greatly boosting SDT for the inhibition of tumor growth. Therefore, the on-demand assembly-disassembly strategy may provide some insight in the design and development of nanoagents for tumor therapy.

•

On-demand assembly from molecules to nanoparticles for longer-blood-circulation.

•

On-demand disassembly in presence of hyaluronidase (in tumor) for boosting sonodynamic effects.

•

Efficient damage on cancer cells in-vitro and Significant inhibition of the tumor growth due to the enhanced SDT.

Water-Soluble Porphyrin-Based Nanoparticles Derived from Electrostatic Interaction for Enhanced Photodynamic Therapy

Pyrrole and porphyrin-derived nanoparticles have great potential use in bioimaging and therapy because of their unique magnetic, optical, and other photophysical properties, whereas the poor solubility in aqueous solution is one of the drawbacks of current photosensitizers for their photodynamic therapy (PDT) applications. Here, we developed a kind of water-soluble porphyrin-based nanoparticles that are coassembled mainly by the electrostatic interaction of anionic porphyrins and cationic tetraphenylmethane derivative. No aggregation-caused quenching (ACQ) was detected for these nanoparticles. In addition, the simple porphyrin transformation into nanoparticles improved their ability to generate reactive oxygen species singlet oxygen (¹O₂), which is an important factor causing apoptosis. The coassembled water-soluble porphyrin-based nanoparticles exhibited enhanced antitumor efficiency via PDT both in vitro and in vivo.

In situ construction of a cobalt oxyhydroxide loaded pyrene-based fluorescent organic nanoprobe for bioimaging of endogenous ascorbic acid in living cells

A novel in situ strategy to fabricate CoOOH nanoflake-loaded pyrene-based FONs (denoted as PyFONs@CoOOH) as proof-of-concept of a sensing platform for direct bioimaging of endogenous AA in living cells.