Host Materials Transformable in Tumor Microenvironment for Homing Theranostics

Tumor Microenvironment Triggered In Situ Coagulation of Supramolecularly Engineered Platelets for Precise Tumor Embolization

Although embolization therapy has demonstrated success in impeding tumor growth, concerns persist regarding potential tumor recurrence and inadvertent embolization of non-target tissues. In this study, drawing inspiration from the natural targeting and coagulation process of platelets in injured blood vessels, platelets are engineered by integrating acid-sensitive, morphology-transformable nanoparticles onto their surface through supramolecular conjugation (PLT-NP). The nanoparticles are constructed through the self-assembly of a β-amyloid derived peptide (FFVLK) terminally functionalized with Fmoc, hexahistidine (His6), and a polyethylene glycol (PEG)-functionalized cyclodextrin (CD). The supramolecularly engineered platelets actively accumulate in the tumor tissue upon inducing a tumor blood vessel injury through tumor resection. In response to the local acidic microenvironment, the nanoparticles undergo a morphological transformation into nanofibers via spontaneous assembly of FFLVK into fibril structures through hydrogen bonding and β-sheet interactions, to artificially enhance the coagulation and aggregation of platelets, causing occlusion of tumor blood vessels. The supramolecularly engineered platelets efficiently embolize tumor blood vessels in a specific manner, effectively suppressing tumor growth, metastasis, and recurrence, thus offering a promising paradigm for combating cancer.

Mechanistic study of enhanced drug release in mixed pH-responsive peptide-loaded liposomes

Liposomes serving as nanocarriers offer significant advantages in drug delivery for tumor treatment. There still exists challenges in controlling drug release by disintegrating the liposome membrane for the improvement of therapeutic efficiency. In this paper, a novel method involving the mixture of short peptides with pH-responsive characteristics into the cargo has been introduced. This approach facilitates the release of doxorubicin (DOX) in the acidic tumor tissue environment. The efficacy of this improvement was elucidated through molecular dynamics simulations and experiments. Liposomes incorporating a 1:1 ratio of peptides-DOX exhibited pronounced pH sensitivity and an enhanced drug release profile. The underlying mechanism is attributed to the peptides entering tumor tissues and undergoing protonation in acidic conditions, which increases the hydrophilicity of the peptide-DOX clusters and the internal surface tension of the liposomes. This alteration disrupts the balance between the inner and outer surface tensions of the nanocarrier, causing the liposomes to structurally disintegrate and thus enhancing drug release. The results from both thermodynamic analysis results and experimental data confirm the augmented drug release efficiency of this method, offering valuable theoretical insights for nanoparticle design and determining the optimal mixing ratio for therapeutic applications.

Biomaterials‐Involved Construction of Extracellular Matrices for Tumor Blockade Therapy

Extracellular matrices (ECMs) play a crucial role in the onset and progression of tumors by providing structural support and promoting the proliferation and metastases of tumor cells. Current therapeutic approaches targeting tumor ECMs focus on two main strategies: Inhibiting matrix degradation to prevent metastases and facilitating matrix degradation to enhance the penetration of drugs and immune cells. However, these strategies may lead to unintended consequences, such as tumor growth promotion, drug resistance, and side effects like fibrotic changes in healthy tissues. Biomaterials have made significant progress in fabricating artificial ECMs for tumor therapy by inducing biomineralization, fibrogenesis, or gelation. This perspective explores the fundamental concepts, benefits, and challenges of each technique. Additionally, future improvements and research directions in artificial ECMs are discussed, highlighting their potential to advance tumor therapy.

Transformable peptide blocks NF-κB/IκBα pathway through targeted coating IκBα against rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by destructive effects. Although current therapies utilizing antibodies against inflammatory cytokines have shown some success, the inhibition of a single inflammatory molecule may not suffice to impede the progression of RA due to the intricate pathogenesis involving multiple molecules. In this study, we have developed an intelligent transformable peptide, namely BP-FFVLK-DSGLDSM (BFD). BFD has the ability to self-assemble into spherical nanoparticles in water or in the blood circulation to facilitate their delivery and distribution. When endocytosed into immune cells, BFD can identify and attach to phosphorylation sites on IκBα and in situ transform into a nanofibrous network coating NF-κB/IκBα complexes, blocking the phosphorylation and degradation of IκBα. As a result, BFD enables decreasing expression of proinflammatory mediators. In the present study, we demonstrate that BFD exhibits notable efficacy in alleviating arthritis-related manifestations, such as joints and tissues swelling, as well as bone and cartilage destruction on the collagen-induced arthritis (CIA) rat model. The investigation of intracellular biodistribution, phosphorylation of IκBα, and cytokine detection in culture medium supernatant, joint tissue, and serum exhibits strong associations with therapeutic outcomes. The utilization of transformable peptide presents a novel approach for the management of inflammatory diseases.

A Peptide-Copper Self-Assembled Nanoparticle for Enhanced Cuproptosis by Metabolic Reprogramming in Tumor Cells

Cuproptosis is a type of metabolic cell death and exhibits great potential for cancer treatment. However, currently, most cuproptosis-based therapies are primarily effective in tumor cells reliant on mitochondrial respiration, limiting their broader application. The Warburg effect highlights that many tumors predominantly rely on glycolysis to meet their rapid metabolic demands, but glycolysis-dependent cells are less sensitive to copper ions than their mitochondrial-respiration-dependent counterparts, making it difficult to induce cuproptosis in these cells. Herein, we designed a copper-loaded peptide-based nanoparticle (MHRC@Cu) to enhance cuproptosis by metabolic reprogramming in a wider range of glycolysis-dependent tumor cells. Specifically, triggered by the acidic environment and laser irradiation, MHRC@Cu effectively released Cu2+ inside the cells. Then the peptide-conjugated probe (MHRC) reprogrammed glycolysis-dependent tumor cells, making them more dependent on mitochondrial respiration and increasing their sensitivity to copper ions. Additionally, the H2O2 generated by the photodynamic effect underwent Fenton reaction with Cu2+ in situ, producing highly toxic ·OH, which depleted GSH and disrupted copper efflux protein, thereby exacerbating copper deposition in cells. Through these synergistic mechanisms, MHRC@Cu significantly enhanced cuproptosis in glycolysis-dependent tumor cells, achieving up to 96% inhibition of tumor growth. This copper-loaded peptide-based nanoparticle offers a versatile and potent strategy for enhancing cuproptosis and may inspire the development of advanced self-assembled nanotherapeutic platforms.

Hydrogel-Mediated Jamming of Exosome Communications That Counter Tumor Adaption in the Tumor Immune Microenvironment

Hypoxia, a common occurrence within solid tumors, can stimulate the dissemination of deceptive tumor exosomes, which function as communicative bridges and orchestrate the recruitment of various supportive cell types for enhanced tumor adaptability in a tumor immune microenvironment. Current nanotechnology provides us intelligent strategies to combat the hypoxic tumor microenvironment. However, once exposed to external stimuli, such as chemotherapy, tumor cells simultaneously release malignant signals to develop tumor migration and immunosuppression, posing challenges to clinical practice. Taking advantage of the membrane-targeting therapeutic strategy, the application of a self-assembled short peptide (PepABS-py), affording hydrogels on tumor cell surfaces, can block exosome dissemination with fiber-like nanostructures and effectively limit the systemic adverse effects of traditional therapeutics. Moreover, PepABS-py can attenuate the hypoxic tumor microenvironment in vivo by carrying an inhibitor of the hypoxic tumor-overexpressed CA IX enzyme, where hypoxia is also a crucial regulator to induce tumor exosomes and mediate intercellular communications within the immune system. Herein, its application on jamming exosome communications can target the T cell-related signaling pathway by regulating microRNAs in exosome cargoes and ultimately enhances CD8+ T cell infiltration and alleviates inflammatory monocytes at metastasis sites. Collectively, with the capability of blocking exosome dissemination, PepABS-py can be applied as a promising tumor membrane-targeting therapeutic tool to counter tumor adaption within an immune microenvironment and further advance traditional chemotherapy.

Synthetic Nanoassemblies for Regulating Organelles: From Molecular Design to Precision Therapeutics

Each organelle referring to a complex multiorder architecture executes respective biological processes via its distinct spatial organization and internal microenvironment. As the assembly of biomolecules is the structural basis of living cells, creating synthetic nanoassemblies with specific physicochemical and morphological properties in living cells to interfere or couple with the natural organelle architectures has attracted great attention in precision therapeutics of cancers. In this review, we give an overview of the latest advances in the synthetic nanoassemblies for precise organelle regulation, including the formation mechanisms, triggering strategies, and biomedical applications in precision therapeutics. We summarize the emerging material systems, including polymers, peptides, and deoxyribonucleic acids (DNAs), and their respective intermolecular interactions for intercellular synthetic nanoassemblies, and highlight their design principles in constructing precursors that assemble into synthetic nanoassemblies targeting specific organelles in the complex cellular environment. We further showcase the developed intracellular synthetic nanoassemblies targeting specific organelles including mitochondria, the endoplasmic reticulum, lysosome, Golgi apparatus, and nucleus and describe their underlying mechanisms for organelle regulation and precision therapeutics for cancer. Last, the essential challenges in this field and prospects for future precision therapeutics of synthetic nanoassemblies are discussed. This review should facilitate the rational design of organelle-targeting synthetic nanoassemblies and the comprehensive recognition of organelles by materials and contribute to the deep understanding and application of the synthetic nanoassemblies for precision therapeutics.

Enzyme-Directed and Organelle-Specific Sphere-to-Fiber Nanotransformation Enhances Photodynamic Therapy in Cancer Cells

Employing responsive nanoplatforms as carriers for photosensitizers represents an effective strategy to overcome the challenges associated with photodynamic therapy (PDT), including poor solubility, low bioavailability, and high systemic toxicity. Drawing inspiration from the morphology transitions in biological systems, a general approach to enhance PDT that utilizes enzyme-responsive nanoplatforms is developed. The transformation of phosphopeptide/photosensitizer co-assembled nanoparticles is first demonstrated into nanofibers when exposed to cytoplasmic enzyme alkaline phosphatase. This transition is primarily driven by alkaline phosphatase-induced changes of the nanoparticles in the hydrophilic and hydrophobic balance, and intermolecular electrostatic interactions within the nanoparticles. The resulting nanofibers exhibit improved ability of generating reactive oxygen species (ROS), intracellular accumulation, and retention in cancer cells. Furthermore, the enzyme-responsive nanoplatform is expanded to selectively target mitochondria by mitochondria-specific enzyme sirtuin 5 (SIRT5). Under the catalysis of SIRT5, the succinylated peptide/photosensitizer co-assembled nanoparticles can be transformed into nanofibers specifically within the mitochondria. The resulting nanofibers exhibit excellent capability of modulating mitochondrial activity, enhanced ROS formation, and significant anticancer efficacy via PDT. Consequently, the enzyme-instructed in situ fibrillar transformation of peptide/photosensitizers co-assembled nanoparticles provides an efficient pathway to address the challenges associated with photosensitizers. It is envisaged that this approach will further expand the toolbox for enzyme-responsive biomaterials for cancer therapy.

Self-assembly antimicrobial peptide for treatment of multidrug-resistant bacterial infection

The wide-spreading of multidrug resistance poses a significant threat to human and animal health. Although antimicrobial peptides (AMPs) show great potential application, their instability has severely limited their clinical application. Here, self-assembled AMPs composed of multiple modules based on the principle of associating natural marine peptide N6 with ß-sheet-forming peptide were designed. It is noteworthy that one of the designed peptides, FFN could self-assemble into nanoparticles at 35.46 µM and achieve a dynamic transformation from nanoparticles to nanofibers in the presence of bacteria, resulting in a significant increase in stability in trypsin and tissues by 1.72-57.5 times compared to that of N6. Additionally, FFN exhibits a broad spectrum of antibacterial activity against multidrug-resistant (MDR) gram-positive (G+) and gram-negative (G-) bacteria with Minimum inhibitory concentrations (MICs) as low as 2 µM by membrane destruction and complemented by nanofiber capture. In vivo mouse mastitis infection model further confirmed the therapeutic potential and promising biosafety of the self-assembled peptide FFN, which can effectively alleviate mastitis caused by MDR Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and eliminate pathogenic bacteria. In conclusion, the design of peptide-based nanomaterials presents a novel approach for the delivery and clinical translation of AMPs, promoting their application in medicine and animal husbandry.

Self-Assembled Peptide with Morphological Structure for Bioapplication

Peptide materials, such as self-assembled peptide materials, are very important biomaterials. Driven by multiple interaction forces, peptide molecules can self-assemble into a variety of different macroscopic forms with different properties and functions. In recent years, the research on self-assembled peptides has made great progress from laboratory design to clinical application. This review focuses on the different morphologies, including nanoparticles, nanovesicles, nanotubes, nanofibers, and others, formed by self-assembled peptide. The mechanisms and applications of the morphology transformation are also discussed in this paper, and the future direction of self-assembled nanomaterials is envisioned.

Biosynthesis of multifunctional transformable peptides for downregulation of PD-L1

Here, we present a biosynthesized material M1 for immune checkpoint blocking therapy. M1 could realize a morphological transformation from globular to fibrous in situ in the presence of cathepsin B (CtsB) after entering tumor cells. The GO203 peptides of M1 are exposed, which could bind to mucin 1 (MUC1) to suppress the homodimerization process of MUC1, thereby downregulating PD-L1 expression.

Recent Progress of pH-Responsive Peptides, Polypeptides, and Their Supramolecular Assemblies for Biomedical Applications

Peptides and polypeptides feature a variety of active functional groups on their side chains (including carboxylic acid, hydroxyl, amino, and thiol groups), enabling diverse chemical modifications. This versatility makes them highly valuable in stimuli-responsive systems. Notably, pH-responsive peptides and polypeptides, due to their ability to respond to pH changes, hold significant promise for applications in cellular pathology and tumor targeting. Extensive researches have highlighted the potentials of low pH insertion peptides (pHLIPs), peptide-drug conjugates (PDCs), and antibody-drug conjugates (ADCs) in biomedicine. Peptide self-assemblies, with their structural stability, ease of regulation, excellent biocompatibility, and biodegradability, offer immense potentials in the development of novel materials and biomedical applications. We also explore specific examples of their applications in drug delivery, tumor targeting, and tissue engineering, while discussing future challenges and potential advancements in the field of pH-responsive self-assembling peptide-based biomaterials.

A Photoactivated Self-Assembled Nanoreactor for Inducing Cascade-Amplified Oxidative Stress toward Type I Photodynamic Therapy in Hypoxic Tumors

Type I photodynamic therapy (PDT) generates reactive oxygen species (ROS) through oxygen-independent photoreactions, making it a promising method for treating hypoxic tumors. However, the superoxide anion (O2∙-) generated usually exhibits a low oxidation capacity, restricting the antitumor efficacy of PDT in clinical practice. Herein, a photoactivated self-assembled nanoreactor (1-NBS@CeO2) is designed through integration of type I PDT and cerium oxide (CeO2) nanozymes for inducing cascade-amplified oxidative stress in hypoxic tumors. The nanoreactor is constructed though co-assembly of an amphiphilic peptide (1-NBS) and CeO2, giving well-dispersed spherical nanoparticles with enhanced superoxide dismutase (SOD)-like and peroxidase (POD)-like activities. Following light irradiation, 1-NBS@CeO2 undergoes type I photoreactions to generated O2∙-, which is further catalyzed by the nanoreactors, ultimately forming hypertoxic hydroxyl radical (∙OH) through cascade-amplified reactions. The PDT treatment using 1-NBS@CeO2 results in elevation of intracellular ROS and depletion of GSH content in A375 cells, thereby inducing mitochondrial dysfunction and triggering apoptosis and ferroptosis of tumor cells. Importantly, intravenous administration of 1-NBS@CeO2 alongside light irradiation showcases enhances antitumor efficacy and satisfactory biocompatibility in vivo. Together, the self-assembled nanoreactor facilitates cascade-amplified photoreactions for achieving efficacious type I PDT, which holds great promise in developing therapeutic modules towards hypoxic tumors.

Three-Dimensional Label-Free Observing of the Self-Assembled Nanoparticles inside a Single Cell at Nanoscale Resolution

Understanding the intracellular behavior of nanoparticles (NPs) plays a key role in optimizing the self-assembly performance of nanomedicine. However, conducting the 3D, label-free, quantitative observation of self-assembled NPs within intact single cells remains a substantial challenge in complicated intracellular environments. Here, we propose a deep learning combined synchrotron radiation hard X-ray nanotomography approach to visualize the self-assembled ultrasmall iron oxide (USIO) NPs in a single cell. The method allows us to explore comprehensive information on NPs, such as their distribution, morphology, location, and interaction with cell organelles, and provides quantitative analysis of the heterogeneous size and morphologies of USIO NPs under diverse conditions. This label-free, in situ method provides a tool for precise characterization of intracellular self-assembled NPs to improve the evaluation and design of a bioresponsive nanomedicine.

Intelligent Biomaterialomics: Molecular Design, Manufacturing, and Biomedical Applications

Materialomics integrates experiment, theory, and computation in a high-throughput manner, and has changed the paradigm for the research and development of new functional materials. Recently, with the rapid development of high-throughput characterization and machine-learning technologies, the establishment of biomaterialomics that tackles complex physiological behaviors has become accessible. Breakthroughs in the clinical translation of nanoparticle-based therapeutics and vaccines have been observed. Herein, recent advances in biomaterials, including polymers, lipid-like materials, and peptides/proteins, discovered through high-throughput screening or machine learning-assisted methods, are summarized. The molecular design of structure-diversified libraries; high-throughput characterization, screening, and preparation; and, their applications in drug delivery and clinical translation are discussed in detail. Furthermore, the prospects and main challenges in future biomaterialomics and high-throughput screening development are highlighted.

A Dual-Responsive Morphologically-Adaptable Nanoplatform for Targeted Delivery of Activatable Photosensitizers in Precision Photodynamic Therapy

Photodynamic therapy (PDT) is an effective approach for treating melanoma. However, the photosensitizers employed in PDT can accumulate in healthy tissues, potentially causing harm to normal cells and resulting in side effects such as heightened photosensitivity. To address this, an activatable photosensitizer (PSD) by linking PpIX with a fluorescence quencher using a disulfide bond is designed. PSD responded to endogenous GSH, showing high selectivity for A375 cells. To enhance PSD's bioavailability and anticancer efficacy, an enzyme-responsive nanoplatform based on a lonidamine-derived self-assembling peptide is developed. Initially, PSD and the peptide self-assembled into nanoparticles, displaying potent tumor targeting of PSD in vivo. Upon cell uptake, these nanoparticles specifically responded to elevated cathepsin B, causing nanoparticle disintegration and releasing PSD and lonidamine prodrug (LND-1). PSD is selectively activated by GSH for cancer-specific fluorescence imaging and precision PDT, while LND-1 targeted mitochondria, forming a fibrous lonidamine depot in situ and intensifying photosensitizer's cytotoxicity through ROS generation, mitochondrial dysfunction, and DNA damage. Notably, intravenous administration of LND-1-PEG@PSD with light irradiation significantly suppressed A375-xenografted mouse tumor growth, with minimal systemic toxicity. Together, the synergy of activatable photosensitizer and enzyme-responsive nanoplatform elevates PDT precision and diminishes side effects, showcasing significant potential in the realm of cancer nanomedicine.

Peptide-containing nanoformulations: Skin barrier penetration and activity contribution

Transdermal drug delivery presents a less invasive pathway, circumventing the need to pass through the gastrointestinal tract and liver, thereby reducing drug breakdown, initial metabolism, and gastrointestinal discomfort. Nevertheless, the unique composition and dense structure of the stratum corneum present a significant barrier to transdermal delivery. This article presents an overview of the current developments in peptides and nanotechnology to address this challenge. Initially, we sum up peptide-containing nanoformulations for transdermal drug delivery, examining them through the lenses of both inorganic and organic materials. Particular emphasis is placed on the diverse roles that peptides play within these nanoformulations, including conferring functionality upon nanocarriers and enhancing the biological efficacy of drugs. Subsequently, we summarize innovative strategies for enhancing skin penetration, categorizing them into passive and active approaches. Lastly, we discuss the therapeutic potential of peptide-containing nanoformulations in addressing a range of diseases, drawing insights from the biological activities and functions of peptides. Furthermore, the challenges hindering clinical translation are also discussed, providing valuable insights for future advancements in transdermal drug delivery.

Biosynthesis of Multifunctional Transformable Peptides for Inducing Tumor Cell Apoptosis

Engineered nanomaterials hold great promise to improve the specificity of disease treatment. Herein, a fully protein-based material is obtained from nonpathogenic Escherichia coli (E. coli), which is capable of morphological transformation from globular to fibrous in situ for inducing tumor cell apoptosis. The protein-based material P1 is comprised of a β-sheet-forming peptide KLVFF, pro-apoptotic protein BAK, and GFP along with targeting moieties. The self-assembled nanoparticles of P1 transform into nanofibers in situ in the presence of cathepsin B, and the generated nanofibrils favor the dimerization of functional BH3 domain of BAK on the mitochondrial outer membrane, leading to efficient anticancer activity both in vitro and in vivo via mitochondria-dependent apoptosis through Bcl-2 pathway. To precisely manipulate the morphological transformation of biosynthetic molecules in living cells, a spatiotemporally controllable anticancer system is constructed by coating P1-expressing E. coli with cationic conjugated polyelectrolytes to release the peptides in situ under light irradiation. The biosynthetic peptide-based enzyme-catalytic transformation strategy in vivo would offer a novel perspective for targeted delivery and shows great potential in precision disease therapeutics.

An adhesive peptide specifically induces microtubule condensation

Cell function-associated biomolecular condensation has great potential in modulation of molecular activities. We develop a microtubule-trapping peptide that first self-assembles into nanoparticles and then in situ transforms into nanofibers via ligand-receptor interactions when targeted to tubulin. The nanofibers support the increased exposed targets for further adhering to microtubules and induce the self-assembly of microtubules into networks due to multivalent effects. Microtubule condensation with prolonged retention in cells for up to 24 h, which is 6 times longer than that of the non-transformable nanoparticle group, efficiently induces in vitro cell apoptosis and inhibits in vivo tumour growth. These smart transformable peptide materials for targeted protein condensation have the potential for improving retention and inducing cell apoptosis in tumour therapy.

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.

Nanoparticles with transformable physicochemical properties for overcoming biological barriers

In recent years, tremendous progress has been made in the development of nanomedicines for advanced therapeutics, yet their unsatisfactory targeting ability hinders the further application of nanomedicines. Nanomaterials undergo a series of processes, from intravenous injection to precise delivery at target sites. Each process faces different or even contradictory requirements for nanoparticles to pass through biological barriers. To overcome biological barriers, researchers have been developing nanomedicines with transformable physicochemical properties in recent years. Physicochemical transformability enables nanomedicines to responsively switch their physicochemical properties, including size, shape, surface charge, etc., thus enabling them to cross a series of biological barriers and achieve maximum delivery efficiency. In this review, we summarize recent developments in nanomedicines with transformable physicochemical properties. First, the biological dilemmas faced by nanomedicines are analyzed. Furthermore, the design and synthesis of nanomaterials with transformable physicochemical properties in terms of size, charge, and shape are summarized. Other switchable physicochemical parameters such as mobility, roughness and mechanical properties, which have been sought after most recently, are also discussed. Finally, the prospects and challenges for nanomedicines with transformable physicochemical properties are highlighted.

Antifungal therapy: Novel drug delivery strategies driven by new targets

In patients with compromised immunity, invasive fungal infections represent a significant cause of mortality. Given the limited availability and drawbacks of existing first-line antifungal drugs, there is a growing interest in exploring novel targets that could facilitate the development of new antifungal agents or enhance the effectiveness of conventional ones. While previous studies have extensively summarized new antifungal targets inherent in fungi for drug development purposes, the exploration of potential targets for novel antifungal drug delivery strategies has received less attention. In this review, we provide an overview of recent advancements in new antifungal drug delivery strategies that leverage novel targets, including those located in the physio-pathological barrier at the site of infection, the infection microenvironment, fungal-host interactions, and the fungal pathogen itself. The objective is to enhance therapeutic efficacy and mitigate toxic effects in fungal infections, particularly in challenging cases such as refractory, recurrent, and drug-resistant invasive fungal infections. We also discuss the current challenges and future prospects associated with target-driven antifungal drug delivery strategies, offering important insights into the clinical implementation of these innovative approaches.

Reprogramming Hypoxic Tumor-Associated Macrophages by Nanoglycoclusters for Boosted Cancer Immunotherapy

The tumor-associated macrophages (TAMs) in intratumoral hypoxic regions are key drivers of immune escape. Reprogramming the hypoxic TAMs to antitumor phenotype holds great therapeutic benefits but remains challenging for current drugs. Here, an in situ activated nanoglycocluster is reported to realize effective tumor penetration and potent repolarization of hypoxic TAMs. Triggered by the hypoxia-upregulated matrix metalloproteinase-2 (MMP-2), the nanoglycocluster is self-assembled from the administered mannose-containing precursor glycopeptides and presents densely-arrayed mannoses to multivalently engage with mannose receptors on M2-like TAMs for efficient phenotype switch. By virtue of the high diffusivity of precursor glycopeptides due to their low molecular mass and weak affinity with TAMs in perivascular regions, the nanoglycoclusters are capable of substantially accumulating in hypoxic areas to strongly interact with local TAMs. This enables the efficient repolarization of overall TAMs with a higher rate than the small-molecule drug R848 and CD40 antibody, and beneficial therapeutic effects in mouse tumor models especially when combining with PD-1 antibody. This on-demand activated immunoagent is endowed with tumor-penetrating properties and inspires the design of diverse intelligent nanomedicines for hypoxia-related cancer immunotherapy.

Photothermal Nanomaterials: A Powerful Light-to-Heat Converter

All forms of energy follow the law of conservation of energy, by which they can be neither created nor destroyed. Light-to-heat conversion as a traditional yet constantly evolving means of converting light into thermal energy has been of enduring appeal to researchers and the public. With the continuous development of advanced nanotechnologies, a variety of photothermal nanomaterials have been endowed with excellent light harvesting and photothermal conversion capabilities for exploring fascinating and prospective applications. Herein we review the latest progresses on photothermal nanomaterials, with a focus on their underlying mechanisms as powerful light-to-heat converters. We present an extensive catalogue of nanostructured photothermal materials, including metallic/semiconductor structures, carbon materials, organic polymers, and two-dimensional materials. The proper material selection and rational structural design for improving the photothermal performance are then discussed. We also provide a representative overview of the latest techniques for probing photothermally generated heat at the nanoscale. We finally review the recent significant developments of photothermal applications and give a brief outlook on the current challenges and future directions of photothermal nanomaterials.

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.

The tumor EPR effect for cancer drug delivery: Current status, limitations, and alternatives

Over the past three decades, the enhanced permeability and retention (EPR) effect has been considered the basis of tumor-targeted drug delivery. Various cancer nanomedicines, including macromolecular drugs, have been designed to utilize this mechanism for preferential extravasation and accumulation in solid tumors. However, such nanomedicines have not yet achieved convincing therapeutic benefits in clinics. Increasing evidence suggests that the EPR effect is over-represented in human tumors, especially in metastatic tumors. This review covers the evolution of the concept, the heterogeneity and limitation of the EPR effect in clinical realities, and prospects for alternative strategies independent of the EPR effect.

Programmable Bispecific Nano-immunoengager That Captures T Cells and Reprograms Tumor Microenvironment

Immune checkpoint blockade (ICB) therapy has revolutionized clinical oncology. However, the efficacy of ICB therapy is limited by the ineffective infiltration of T effector (T_eff) cells to tumors and the immunosuppressive tumor microenvironment (TME). Here, we report a programmable tumor cells/T_eff cells bispecific nano-immunoengager (NIE) that can circumvent these limitations to improve ICB therapy. The peptidic nanoparticles (NIE-NPs) bind tumor cell surface α₃β₁ integrin and undergo in situ transformation into nanofibrillar network nanofibers (NIE-NFs). The prolonged retained nanofibrillar network at the TME captures T_eff cells via the activatable α₄β₁ integrin ligand and allows sustained release of resiquimod for immunomodulation. This bispecific NIE eliminates syngeneic 4T1 breast cancer and Lewis lung cancer models in mice, when given together with anti-PD-1 antibody. The in vivo structural transformation-based supramolecular bispecific NIE represents an innovative class of programmable receptor-mediated targeted immunotherapeutics to greatly enhance ICB therapy against cancers.

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.

Nano-bio interactions: A major principle in the dynamic biological processes of nano-assemblies

Controllable nano-assembly with stimuli-responsive groups is emerging as a powerful strategy to generate theranostic nanosystems that meet unique requirements in modern medicine. However, this prospective field is still in a proof-of-concept stage due to the gaps in our understanding of complex-(nano-assemblies)-complex-(biosystems) interactions. Indeed, stimuli-responsive assembly-disassembly is, in and of itself, a process of nano-bio interactions, the key steps for biological fate and functional activity of nano-assemblies. To provide a comprehensive understanding of these interactions in this review, we first propose a 4W1H principle (Where, When, What, Which and How) to delineate the relevant dynamic biological processes, behaviour and fate of nano-assemblies. We further summarize several key parameters that govern effective nano-bio interactions. The effects of these kinetic parameters on ADMET processes (absorption, distribution, metabolism, excretion and transformation) are then discussed. Furthermore, we provide an overview of the challenges facing the evaluation of nano-bio interactions of assembled nanodrugs. We finally conclude with future perspectives on safe-by-design and application-driven-design of nano-assemblies. This review will highlight the dynamic biological and physicochemical parameters of nano-bio interactions and bridge discrete concepts to build a full spectrum understanding of the biological outcomes of nano-assemblies. These principles are expected to pave the way for future development and clinical translation of precise, safe and effective nanomedicines with intelligent theranostic features.

Spermine-Responsive Intracellular Self-Aggregation of Gold Nanocages for Enhanced Chemotherapy and Photothermal Therapy of Breast Cancer

Improving the precise accumulation and retention of nanomedicines in tumor cells is one of the keys to effective therapy of tumors. Herein, supramolecular peptides capped Au nanocages (AuNCs) that may self-aggregate into micron-sized clusters intracellularly in response to spermine (SPM), leading to specific accumulation and retention of AuNCs in SPM-overexpressed tumor cells, are developed. In this design, polydopamine (PDA) is in situ coated on the surface of AuNCs with doxorubicin (DOX) encapsulated. A small peptide, Phe-Phe-Val-Leu-Lys (FFVLK), is conjugated with PDA via esterification, and cucurbit[7]uril (CB[7]) is threaded onto the N-terminal Phe via host-guest interactions. Once the supramolecular peptide (CB[7]-FFVLK) capped AuNCs are internalized in SPM-overexpressed breast cancer cells, CB[7] can be competitively removed from FFVLK by SPM, due to the much higher binding affinity between CB[7] and SPM than that between CB[7] and Phe, leading to exposure of free FFVLK, which can subsequently self-assemble and induce the aggregation of AuNCs to micron-sized clusters, resulting in the significantly enhanced accumulation and retention of DOX-loaded AuNCs in tumor cells. Under NIR laser irradiation, the enhanced photothermal conversion of AuNCs aggregates, together with photothermia-induced release of DOX leads to synergistic photothermal therapy and chemotherapy against breast cancer.

Designing Self-Assembling Chimeric Peptide Nanoparticles with High Stability for Combating Piglet Bacterial Infections

As a novel type of antibiotic alternative, peptide-based antibacterial drug shows potential application prospects attributable to their unique mechanism for lysing the membrane of pathogenic bacteria. However, peptide-based antibacterial drugs suffer from a series of problems, most notably their immature stability, which seriously hinders their application. In this study, self-assembling chimeric peptide nanoparticles (which offer excellent stability in the presence of proteases and salts) are constructed and applied to the treatment of bacterial infections. In vitro studies are used to demonstrate that peptide nanoparticles NPs1 and NPs2 offer broad-spectrum antibacterial activity and desirable biocompatibility, and they retain their antibacterial ability in physiological salt environments. Peptide nanoparticles NPs1 and NPs2 can resist degradation under high concentrations of proteases. In vivo studies illustrate that the toxicity caused by peptide nanoparticles NPs1 and NPs2 is negligible, and these nanoparticles can alleviate systemic bacterial infections in mice and piglets. The membrane permeation mechanism and interference with the cell cycle differ from that of antibiotics and mean that the nanoparticles are at a lower risk of inducing drug resistance. Collectively, these advances may accelerate the development of peptide-based antibacterial nanomaterials and can be applied to the construction of supramolecular nanomaterials.

Self-assembling, pH-responsive nanoflowers for inhibiting PAD4 and neutrophil extracellular trap formation and improving the tumor immune microenvironment

Self-assembling carrier-free nanodrugs are attractive agents because they accumulate at tumor by an enhanced permeability and retention (EPR) effect without introduction of inactive substances, and some nanodrugs can alter the immune environment. We synthesized a peptidyl arginine deiminase 4 (PAD4) molecular inhibitor, ZD-E-1M. It could self-assembled into nanodrug ZD-E-1. Using confocal laser scanning microscopy, we observed its cellular colocalization, PAD4 activity and neutrophil extracellular traps (NETs) formation. The populations of immune cells and expression of immune-related proteins were determined by single-cell mass cytometry. ZD-E-1 formed nanoflowers in an acidic environment, whereas it formed nanospheres at pH 7.4. Accumulation of ZD-E-1 at tumor was pH-responsive because of its pH-dependent differences in the size and shape. It could enter the nucleus and bind to PAD4 to prolong the intracellular retention time. In mice, ZD-E-1 inhibited tumor growth and metastasis by inhibiting PAD4 activity and NETs formation. Besides, ZD-E-1 could regulate the ratio of immune cells in LLC tumor-bearing mice. Immunosuppressive proteins like LAG3 were suppressed, while IFN-γ and TNF-α as stimulators of tumor immune response were upregulated. Overall, ZD-E-1 is a self-assembling carrier-free nanodrug that responds to pH, inhibits PAD4 activity, blocks neutrophil extracellular traps formation, and improves the tumor immune microenvironment.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

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.

Self-assembly and disassembly mechanisms of biomimetic peptides: Molecular dynamics simulation and experimental measurement

Drug-loaded pH-responsive nanoparticles are potential drug carriers in nanotherapeutics delivery because they can remain stable in normal tissues but can disassemble and release drug molecules in tumors. In this study, the mechanisms of self-assembly and disassembly were investigated by analyzing the characteristics of three kinds of biomimetic peptides with different components and sequences. The structural parameters and energy changes during self-assembly and disassembly were calculated by molecular dynamics simulation. Transmission electron microscopy, Fourier transform infrared spectroscopy, and atomic force microscopy were used to observe morphological changes and measure the strength of hydrophobic and hydrophilic interactions between peptides. Results show that the hydrophobic and hydrophilic interactions play crucial roles in the self-assembly and disassembly processes of peptides. The structure of the peptide clusters after self-assembly became tighter as the difference between hydrophobic and hydrophilic interactions increased, whereas a decrease in this difference led to the increased disassembly of the peptides. In general, polyethylene glycol chain modification was necessary in disassembly, and peptides with straight structures had stronger disassembly ability than that with branched structures with the same components. The morphology of peptide clusters can be controlled under different pH values by changing the composition and structure of the peptides for enhanced drug retention and sustained release.

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.

When imaging meets size-transformable nanosystems

Imaging techniques, including magnetic, optical, acoustic and nuclear imaging, are gaining popularity as a research tool and clinical diagnostics. The advent of imaging agents-incorporated nanosystems (NSs), with sufficient contrast and high resolution, facilitates better monitoring of disease progression, targeted delivery and therapeutic process. Of note, the size of NSs remarkably affects imaging performance, while both large and small NSs enjoy respective features and superiority for imaging aspect, including penetration depth, signal-to-background ratio and spatiotemporal resolution. In this review, after a systematic summary of the basic knowledge of imaging techniques and its relation with size-tunable strategies, we further provide insights into the opportunities and challenges facing size-transformable NSs of the future for bio-imaging application and clinical translation.

Rational Design of Peptide-based Smart Hydrogels for Therapeutic Applications

Peptide-based hydrogels have captivated remarkable attention in recent times and serve as an excellent platform for biomedical applications owing to the impressive amalgamation of unique properties such as biocompatibility, biodegradability, easily tunable hydrophilicity/hydrophobicity, modular incorporation of stimuli sensitivity and other functionalities, adjustable mechanical stiffness/rigidity and close mimicry to biological molecules. Putting all these on the same plate offers smart soft materials that can be used for tissue engineering, drug delivery, 3D bioprinting, wound healing to name a few. A plethora of work has been accomplished and a significant progress has been realized using these peptide-based platforms. However, designing hydrogelators with the desired functionalities and their self-assembled nanostructures is still highly serendipitous in nature and thus a roadmap providing guidelines toward designing and preparing these soft-materials and applying them for a desired goal is a pressing need of the hour. This review aims to provide a concise outline for that purpose and the design principles of peptide-based hydrogels along with their potential for biomedical applications are discussed with the help of selected recent reports.

Enzyme-Induced Transformable Peptide Nanocarriers with Enhanced Drug Permeability and Retention to Improve Tumor Nanotherapy Efficacy

Temporal persistence is as important for nanocarriers as spatial accuracy. However, because of the insufficient aggreagtion and short retention time of chemotherapy drugs in tumors, their clinical application is greatly limited. A drug delivery approach dependent on the sensitivity to an enzyme present in the microenvironment of the tumor is designed to exhibit different sizes in different sites, achieving enhanced drug permeability and retention to improve tumor nanotherapy efficacy. In this work, we report a small-molecule peptide drug delivery system containing both tumor-targeting groups and enzyme response sites. This system enables the targeted delivery of peptide nanocarriers to tumor cells and a unique response to alkaline phosphatase (ALP) in the tumor microenvironment to activate morphological transformation and drug release. The amphiphilic peptide AYR self-aggregated into a spherical nanoparticle structure after encapsulating the lipid-soluble model drug doxorubicin (DOX) and rapidly converted to nanofibers via the induction of ALP. This morphological transformation toward a high aspect ratio allowed rapid, as well as effective drug release to tumor location while enhancing specific toxicity to tumor cells. Interestingly, this "transformer"-like drug delivery strategy can enhance local drug accumulation and effectively inhibit drug efflux. In vitro along with in vivo experiments further proved that the permeability and retention of antitumor drugs in tumor cells and tissues were significantly enhanced to reduce toxic side effects, and the therapeutic effect was remarkably improved compared with that of nondeformable drug-loaded peptide nanocarriers. The developed AYR nanoparticles with the ability to undergo morphological transformation in situ can improve local drug aggregation and retention time at the tumor site. Our findings provide a new and simple method for nanocarrier morphology transformation in novel cancer treatments.

Dynamic nanoassembly-based drug delivery systems on the horizon

Self-assembly in nature creates matter with complex structures and unpredictable designs; disordered building blocks spontaneously organize into ordered structures to achieve specific functions. Self-assembly begins to play an important role in the design of advanced drug delivery as well. Though, the behavior of 'dynamic nanoassembly-based drug delivery systems' (DNDDS) in biological media and cells remains poorly understood, while this is highly critical for controlling spatiotemporal drug release from DNDDS in vivo. To deepen the understanding of tailor-made DNDDS, this contribution in the Oration - New Horizons section of the Journal of controlled Release aims to highlight nature-inspired designs, construction principles, and controllable functionalities of DNDDS and how they are triggered by endogenous and exogenous stimuli. Furthermore, biomedical applications of tailor-made DNDDS for accurate diagnosis and precise treatment of diseases, including tumors, neurological diseases, injuries and infections are discussed. Finally, current challenges and future perspectives of DNDDS are briefly outlined.

Light-triggered nitric oxide release and structure transformation of peptide for enhanced intratumoral retention and sensitized photodynamic therapy

Tumor-targeted delivery of nanomedicine is of great importance to improve therapeutic efficacy of cancer and minimize systemic side effects. Unfortunately, nowadays the targeting efficiency of nanomedicine toward tumor is still quite limited and far from clinical requirements. In this work, we develop an innovative peptide-based nanoparticle to realize light-triggered nitric oxide (NO) release and structural transformation for enhanced intratumoral retention and simultaneously sensitizing photodynamic therapy (PDT). The designed nanoparticle is self-assembled from a chimeric peptide monomer, TPP-RRRKLVFFK-Ce6, which contains a photosensitive moiety (chlorin e6, Ce6), a β-sheet-forming peptide domain (Lys-Leu-Val-Phe-Phe, KLVFF), an oligoarginine domain (RRR) as NO donor and a triphenylphosphonium (TPP) moiety for targeting mitochondria. When irradiated by light, the constructed nanoparticles undergo rapid structural transformation from nanosphere to nanorod, enabling to achieve a significantly higher intratumoral accumulation by 3.26 times compared to that without light irradiation. More importantly, the conversion of generated NO and reactive oxygen species (ROS) in a light-responsive way to peroxynitrite anions (ONOO^-) with higher cytotoxicity enables NO to sensitize PDT in cancer treatment. Both in vitro and in vivo studies demonstrate that NO sensitized PDT based on the well-designed transformable nanoparticles enables to eradicate tumors efficiently. The light-triggered transformable nanoplatform developed in this work provides a new strategy for enhanced intratumoral retention and improved therapeutic outcome.

Polyamine-Responsive Morphological Transformation of a Supramolecular Peptide for Specific Drug Accumulation and Retention in Cancer Cells

The precise accumulation and extended retention of nanomedicines in the tumor tissue has been highly desired for cancer therapy. Here a novel supramolecular-peptide derived nanodrug (SPN) that can be transformed to microfibers in response to intracellular polyamine in cancer cells for significantly enhanced tumor specific accumulation and retention is developed. The supramolecular-peptide is constructed via the non-covalent interactions between cucurbit[7]uril (CB[7]) and Phe on Phe-Phe-Val-Leu-Lys-camptothecin conjugates (FFVLK-CPT, PC). The resultant amphiphilic supramolecular complex subsequently self-assembles into nanoparticles with a hydrodynamic diameter of 164.2 ± 3.7 nm. Upon internalization into spermine-overexpressed cancer cells, the CB[7]-Phe host-guest pairs can be competitively dissociated by spermine and can release free PC, which immediately form β-sheet structures and subsequently reorganize into microfibers, leading to dramatically improved accumulation, retention, and sustained release of CPT in tumor cells for highly effective cancer therapy. Accordingly, this SPN exhibit rather low toxicity against non-cancerous cells due to the morphological stability and fast exocytosis of the nanodrugs in those cells without abundant spermine. This study reports the first supramolecular peptide capable of polyamine-responsive "nanoparticle-to-microfiber" transformation for specific tumor therapy with minimal side effects. This work also offers novel insights to the design and development of stimuli-responsive nanomaterials as precision medicine.

Transformable amyloid-beta mimetic peptide amphiphiles for lysosomal disruption in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the largest contributor to cancer mortality in the United States. Traditional chemotherapies are toxic and prone to the development of drug-resistance. Recently, several drug candidates were shown to induce lysosomal membrane permeabilization (LMP) in aggressive cancers. This has led to increased interest in lysosome dysregulation as a therapeutic target. However, approaches are needed to overcome two limitations of current lysosomal inhibitors: low specificity and potency. Here, we report the development of a transformable nanomaterial which is triggered to induce LMP of lysosomes in NSCLC. The nanomaterial consists of peptide amphiphiles, which self-assemble into nanoparticles, colocalize with the lysosome, and change conformation to nanofibrils due to lysosomal pH shift, which leads to the disruption of the lysosome, cell death, and cisplatin sensitization. We have found that this cell-penetrating transformable peptide nanoparticle (CPTNP) was cytotoxic to NSCLC cells in the low-micromolar range and it synergized cisplatin cytotoxicity four-fold. Moreover, we demonstrate CPTNP's promising antitumor effect in mouse xenograft models with limited toxicity when given in combination with low dose cisplatin chemotherapy. This is the first example of enhanced LMP via transformable peptide nanomaterial and offers a promising new strategy for cancer therapy.

Glycopeptide-Conjugated Aggregation-Induced Emission Luminogen: A pH-Responsive Fluorescence Probe with Tunable Self-Assembly Morphologies for Cell Imaging

pH values play an important role in various cell biological processes. Abnormal pH values in living systems are frequently associated with the development of diseases such as cancers, infection, and other diseases. Real-time monitoring of the changes of pH values in vivo will give us the significant indication for these diseases' progression. Within those pH-sensitive imaging probes, aggregation-induced emission (AIE) molecules exhibit great potential in aqueous imaging environment due to their high fluorescence quantum yield and stability. However, the modulation of the AIE probe with pH sensitivity and light-up property face challenges. Here, we introduced a new glycopeptide-modified AIE probe (TGO) based on the optimized solid-phase peptide synthesis approach. The response to pH of the peptide: DDDD progression changed hydrophobicity and hydrophilicity, resulting in the change of the amphipathicity balance. When modulating the pH from 5.5 to 8.0, the adverse protonation of the peptide induced assembled nanostructure transformation from nanolamellae to nanomicelles. Meanwhile, the pH-induced charge change in peptides can greatly influence the microenvironment of the AIEgen, resulting in the increase of fluorescence intensity.