Supramolecular “Trojan Horse” for Nuclear Delivery of Dual Anticancer Drugs

Copper-Induced Supramolecular Peptide Assemblies for Multi-Pathway Cell Death and Tumor Inhibition

Although self-assembly has emerged as an effective tool for fabricating biomaterials, achieving precise control over the morphologies and functionalities of the resultant assemblies remains an ongoing challenge. Inspired by the copper peptide naturally present in human plasma, in this study, we designed a synthetic precursor, FcGH. FcGH can self-assemble via two distinct pathways: spontaneous and Cu2+-induced. These two assembly pathways enabled the formation of assemblies with tunable morphologies by adjusting the amount of added Cu2+. We found that the nanoparticles formed by Cu2+-induced self-assembly exhibited a significantly higher cellular uptake efficiency than the wormlike fibers formed spontaneously. Moreover, this Cu2+-induced assembly process occurred spontaneously at a 1 : 1 molar ratio of Cu2+ to FcGH, avoiding the excessive use of Cu2+ and a tedious preparation procedure. By co-assembling with 10-hydroxycamptothecin (HCPT)-conjugated FcGH, Cu2+-induced supramolecular nanodrugs elicited multiple cell death modalities in cancer cells with elevated immunogenicity, enhancing the therapeutic effect compared to free HCPT. This study highlights Cu2+-induced self-assembly as an efficient tool for directing the assembly of nanodrugs and for synergistic tumor therapy.

Adaptive enzyme-responsive self-assembling multivalent apelin ligands for targeted myocardial infarction therapy

Microvascular dysfunction following myocardial infarction exacerbates coronary flow obstruction and impairs the preservation of ventricular function. The apelinergic system, known for its pleiotropic effects on improving vascular function and repairing ischemic myocardium, has emerged as a promising therapeutic target for myocardial infarction. Despite its potential, the natural apelin peptide has an extremely short circulating half-life. Current apelin analogs have limited receptor binding efficacy and poor targeting, which restricts their clinical applications. In this study, we utilized an enzyme-responsive peptide self-assembly technique to develop an enzyme-responsive small molecule peptide that adapts to the expression levels of matrix metalloproteinases in myocardial infarction lesions. This peptide is engineered to respond to the high concentration of matrix metalloproteinases in the lesion area, allowing for precise and abundant presentation of the apelin motif. The changes in hydrophobicity allow the apelin motif to self-assemble into a supramolecular multivalent peptide ligand-SAMP. This self-assembly behavior not only prolongs the residence time of apelin in the myocardial infarction lesion but also enhances the receptor-ligand interaction through increased receptor binding affinity due to multivalency. Studies have demonstrated that SAMP significantly promotes angiogenesis after ischemia, reduces cardiomyocyte apoptosis, and improves cardiac function. This novel therapeutic strategy offers a new approach to restoring coronary microvascular function and improving damaged myocardium after myocardial infarction.

Nanoassemblies designed for efficient nuclear targeting

One of the key aspects of coping efficiently with complex pathological conditions is delivering the desired therapeutic compounds with precision in both space and time. Therefore, the focus on nuclear-targeted delivery systems has emerged as a promising strategy with high potential, particularly in gene therapy and cancer treatment. Here, we explore the design of supramolecular nanoassemblies as vehicles to deliver specific compounds to the nucleus, with the special focus on polymer and peptide-based carriers that expose nuclear localization signals. Such nanoassemblies aim at maximizing the concentration of genetic and therapeutic agents within the nucleus, thereby optimizing treatment outcomes while minimizing off-target effects. A complex scenario of conditions, including cellular uptake, endosomal escape, and nuclear translocation, requires fine tuning of the nanocarriers' properties. First, we introduce the principles of nuclear import and the role of nuclear pore complexes that reveal strategies for targeting nanosystems to the nucleus. Then, we provide an overview of cargoes that rely on nuclear localization for optimal activity as their integrity and accumulation are crucial parameters to consider when designing a suitable delivery system. Considering that they are in their early stages of research, we present various cargo-loaded peptide- and polymer nanoassemblies that promote nuclear targeting, emphasizing their potential to enhance therapeutic response. Finally, we briefly discuss further advancements for more precise and effective nuclear delivery.

Programmable "triple attack" cancer therapy through in situ activation of disulfiram toxification combined with phototherapeutics

Effectively and completely eliminating residual tumor cells is the key to reducing the risk of tumor metastasis and recurrence. Designing an "ideal" nanoplatform for programmable cancer therapy has great prospects for completely eliminating residual tumor cells. Herein, an intelligent nanoplatform of disulfiram (DSF)-loaded CuS-tannic acid nanohexahedrons (denoted as "DSF-CuS@TA") with thermal- and pH-sensitive degradation, as well as near-infrared (NIR-II) phototherapeutics properties, was constructed. And then, it was employed for in situ DSF toxification activation programmable "triple attack" cancer therapy. After accumulating in the tumor, DSF-CuS@TA first releases the loaded Cu(DTC)2, and simultaneously degrades and releases Cu2+ and DSF under mildly acidic stimulation to trigger instant intratumoral Cu(DTC)2 chelation, thereby achieving the "first strike." Next, under irradiation by a NIR-II laser, light energy is converted into heat to generate NIR-II photothermal therapy, thereby achieving the second strike. Subsequently, under thermal stimulation, DSF-CuS@TA degrades further, triggering the chelation of Cu(DTC)2 for a second time to reach the third strike. As expected, in vitro and in vivo studies showed that the synergistic integration of DSF-based programmed chemotherapy and NIR-II phototherapeutics could achieve effective tumor removal. Therefore, we propose a novel type of programmed therapy against cancer by designing a nanoplatform via "nontoxicity-to-toxicity" chemical chelation transformation.

An in-situ peptide-antibody self-assembly to block CD47 and CD24 signaling enhances macrophage-mediated phagocytosis and anti-tumor immune responses

Targeted immunomodulation for reactivating innate cells, especially macrophages, holds great promise to complement current adaptive immunotherapy. Nevertheless, there is still a lack of high-performance therapeutics for blocking macrophage phagocytosis checkpoint inhibitors in solid tumors. Herein, a peptide-antibody combo-supramolecular in situ assembled CD47 and CD24 bi-target inhibitor (PAC-SABI) is described, which undergoes biomimetic surface propagation on cancer cell membranes through ligand-receptor binding and enzyme-triggered reactions. By simultaneously blocking CD47 and CD24 signaling, PAC-SABI enhances the phagocytic ability of macrophages in vitro and in vivo, promoting anti-tumor responses in breast and pancreatic cancer mouse models. Moreover, building on the foundation of PAC-SABI-induced macrophage repolarization and increased CD8+ T cell tumor infiltration, sequential anti-PD-1 therapy further suppresses 4T1 tumor progression, prolonging survival rate. The in vivo construction of PAC-SABI-based nano-architectonics provides an efficient platform for bridging innate and adaptive immunity to maximize therapeutic potency.

Supramolecular assembly of isomeric SN-38 prodrugs regulated by conjugation sites

Supramolecular polymers (SPs) are an emerging class of drug transporters employed to improve drug therapy. Through the rational design of self-assembling monomers, one can optimize the properties of the resulting supramolecular nanostructures, such as size, shape, surface chemistry, release, and, therefore, biological fates. This study highlights the design of isomeric SN38 prodrugs through the conjugation of hydrophilic oligo(ethylene glycol) (OEG) with hydroxyls at positions 10 and 20 on hydrophobic SN-38. Self-assembling prodrug (SAPD) isomers 10-OEG-SN38 and 20-OEG-SN38 can self-assemble into giant nanotubes and filamentous assemblies, respectively, via aromatic associations that dominate self-assembly. Our study reveales the influence of modification sites on the assembly behavior and ability of the SN38 SAPDs, as well as drug release and subsequent in vitro and in vivo antitumor effects. The SAPD modified at position 20 exhibits stronger π-π interactions among SN38 units, leading to more compact packing and enhanced assembly capability, whereas OEG at position 10 poses steric hindrance for aromatic associations. Importantly, owing to its higher chemical and supramolecular stability, 20-OEG-SN38 outperforms 10-OEG-SN38 and irinotecan, a clinically used prodrug of SN38, in a CT26 tumor model, demonstrating enhanced tumor growth inhibition and prolonged animal survival. This study presents a new strategy of using interactions among drug molecules as dominating features to create supramolecular assemblies. It also brings some insights into creating effective supramolecular drug assemblies via the engineering of self-assembling building blocks, which could contribute to the optimization of design principles for supramolecular drug delivery systems.

Lysosomal Peptide Self-Assembly to Control Cell Behavior

Lysosomes are membrane-enclosed organelles that play key roles in degrading and recycling cellular debris, cellular signaling, and energy metabolism processes. Confinement of amphiphilic peptides in the lysosome to construct functional nanostructures through noncovalent interactions is an emerging approach to tune the homeostasis of lysosome. After briefly introducing the importance of lysosome and its functions, we discuss the advantages of lysosomal nanostructure formation for disease therapy. We next discuss the strategy for triggering the self-assembly of peptides in the lysosome, followed by a concise outlook of the future perspective about this emerging research direction.

Applications of self-assembled peptide hydrogels in anti-tumor therapy

Peptides are a class of active substances composed of a variety of amino acids with special physiological functions. The rational design of peptide sequences at the molecular level enables their folding into diverse secondary structures. This property has garnered significant attention in the biomedical sphere owing to their favorable biocompatibility, adaptable mechanical traits, and exceptional loading capabilities. Concurrently with advancements in modern medicine, the diagnosis and treatment of tumors have increasingly embraced targeted and personalized approaches. This review explores recent applications of self-assembled peptides derived from natural amino acids in chemical therapy, immunotherapy, and other adjunctive treatments. We highlighted the utilization of peptide hydrogels as delivery systems for chemotherapeutic drugs and other bioactive molecules and then discussed the challenges and prospects for their future application.

From cells to subcellular organelles: Next-generation cancer therapy based on peptide self-assembly

Due to the editability, functionality, and excellent biocompatibility of peptides, in situ self-assembly of peptides in cells is a powerful strategy for biomedical applications. Subcellular organelle targeting of peptides assemblies enables more precise drug delivery, enhances selectivity to disease cells, and mitigates drug resistance, providing an effective strategy for disease diagnosis and therapy. This reviewer first introduces the triggering conditions, morphological changes, and intracellular locations of self-assembling peptides. Then, the functions of peptide assemblies are summarized, followed by a comprehensive understanding of the interactions between peptide assemblies and subcellular organelles. Finally, we provide a brief outlook and the remaining challenges in this field.

Three-in-One Peptide Prodrug with Targeting, Assembly and Release Properties for Overcoming Bacterium-Induced Drug Resistance and Potentiating Anti-Cancer Immune Response

The presence of bacteria in tumor results in chemotherapeutic drug resistance and weakens the immune response in colorectal cancer. To overcome bacterium-induced chemotherapeutic drug resistance and potentiate antitumor immunity, herein a novel molecule Biotin-Lys(SA-Cip-OH)-Lys(SA-CPT)-Phe-Phe-Nap (Biotin-Cip-CPT-Nap) is rationally designed containing four functional motifs (i.e., a biotin motif for targeting, Phe-Phe(-Nap) motif for self-assembly, ciprofloxacin derivative (Cip-OH) motif for antibacterial effect, and camptothecin (CPT) motif for chemotherapy). Using the designed molecule, a novel strategy of intracellular enzymatic nanofiber formation and synergistic antibacterium-enhanced chemotherapy and immunotherapy is achieved. Under endocytosis mediated by highly expressed biotin receptor in colorectal cancer cell membrane and the catalysis of highly expressed carboxylesterase in the cytoplasm, this novel molecule can be transformed into Biotin-Nap, which self-assembled into nanofibers. Meanwhile, antibiotic Cip-OH and chemotherapeutic drug CPT are released, overcoming bacterium-induced drug resistance and enhancing the therapeutic efficacy of immunotherapy towards colorectal cancer. This work offers a feasible strategy for the design of novel multifunctional prodrugs to improve the efficiency of colorectal cancer treatment.

Intranuclear assembly of leucine-rich peptides for selective death of osteosarcoma cells

Herein, we show a pair of leucine-rich L- and D-phosphopeptides which self-assemble into twisting nanofibers, whose secondary structures contain a strong β-sheet component after being dephosphorylated by alkaline phosphatase (ALP). While being incubated with ALP overexpressing osteosarcoma cells, both of the peptides self-assemble in the nuclei and induce cell death. The cell death involves multiple cell death modalities and occurs along with the disruption of cell membranes. Enzyme-instructed self-assembly (EISA) inhibits osteosarcoma cells and shows no side effect to other cells. In addition, the cancer cells hardly gain drug resistance after repeated treatment. This work reports a pair of EISA-based nanofibers to target cell nuclei, and also provides a novel chemotherapeutic agent to inhibit osteosarcoma cells without side effects and drug resistance.

Water-Based Synthesis of β-Sheet-Like Supramolecular Metallohydrogel Organized by Using a Native Ultrashort Peptide Sequence

Designing supramolecular hydrogels using short peptides is challenging. To control self-assembly, a certain amount of organic solvent is typically added to the system, or the short peptide is modified with a functional group that is hydrophobic, hydrophilic, or highly coordinative. We discovered that l-His-l-Ile-l-Thr (HIT), a very short unmodified "native" tripeptide, selectively responds to Cu2+ ions in pure water to form a transparent supramolecular metallohydrogel. Circular dichroism analysis revealed that Cu2+ ions, but no other metal species, caused HIT to change from a random-coil-like to a β-sheet-like structure. Other spectroscopic methods were used to characterize the properties of the supramolecular metallohydrogel. These results are expected to facilitate the development of native short peptides as advanced functional biomaterials.

Effect of Modification Strategies on the Biological Activity of Peptides/Proteins

Covalent attachment of biologically active peptides/proteins with functional moieties is an effective strategy to control their biodistribution, pharmacokinetics, enzymatic digestion, and toxicity. This review focuses on the characteristics of different modification strategies and their effects on the biological activity of peptides/proteins and illustrates their relevant applications and potential.

Baicalin-peptide supramolecular self-assembled nanofibers effectively inhibit ferroptosis and attenuate doxorubicin-induced cardiotoxicity

Doxorubicin, an anthracycline chemotherapeutic agent, elicits a deleterious cardiotoxicity known as doxorubicin-induced cardiomyopathy (DIC) that circumscribes its chemotherapy utility for malignancies. Recent empirical evidence implicates ferroptosis, an iron-dependent form of regulated cell death, as playing a pivotal role in the pathogenesis of DIC. We postulated that anti-ferroptosis agents may constitute a novel therapeutic strategy for mitigating DIC. To test this hypothesis, we engineered baicalin-peptide supramolecular self-assembled nanofibers designed to selectively target the angiotensin II type I receptor (AT1R), which is upregulated in doxorubicin-damaged cardiomyocytes. This enabled targeted delivery of baicalin, a natural antioxidant compound, to inhibit ferroptosis in the afflicted myocardium. In vitro, the nanofibers ameliorated cardiomyocyte death by attenuating peroxide accumulation and suppressing ferroptosis. In a murine model of DIC, AT1R-targeted baicalin delivery resulted in efficacious cardiac accumulation and superior therapeutic effects compared to systemic administration. This investigation delineates a promising framework for developing targeted therapies that alleviate doxorubicin-induced cardiotoxicity by inhibiting the ferroptosis pathway in cardiomyocytes.

Aflibercept Loaded Eye-Drop Hydrogel Mediated with Cell-Penetrating Peptide for Corneal Neovascularization Treatment

Corneal neovascularization (CoNV) is a major cause of visual impairment worldwide. Currently, available treatment options have limited efficacy and are associated with adverse effects due to biological barriers and clearance mechanisms. To address this challenge, a novel topical delivery system is developed-Gel 2_1&Eylea-an aflibercept-loaded eye-drop hydrogel mediated with cell-penetrating peptide 1. Gel 2_1&Eylea demonstrates superior membrane permeability, increased stability, and prolonged drug retention time on the ocular surface, and thus may improve drug efficacy. In a rabbit CoNV model, Gel 2_1&Eylea significantly reduces the density of neovascularization with no adverse effects on normal corneoscleral limbal vessels, demonstrating high efficacy and biocompatibility. This work identifies a promising treatment for CoNV which has the potential to benefit other ocular neovascular diseases.

Supramolecular self-assembled peptide-engineered nanofibers: A propitious proposition for cancer therapy

Cancer is a devastating disease that causes a substantial number of deaths worldwide. Current therapeutic interventions for cancer include chemotherapy, radiation therapy, or surgery. These conventional therapeutic approaches are associated with disadvantages such as multidrug resistance, destruction of healthy tissues, and tissue toxicity. Therefore, there is a paradigm shift in cancer management wherein nanomedicine-based novel therapeutic interventions are being explored to overcome the aforementioned disadvantages. Supramolecular self-assembled peptide nanofibers are emerging drug delivery vehicles that have gained much attention in cancer management owing to their biocompatibility, biodegradability, biomimetic property, stimuli-responsiveness, transformability, and inherent therapeutic property. Supramolecules form well-organized structures via non-covalent linkages, the intricate molecular arrangement helps to improve tissue permeation, pharmacokinetic profile and chemical stability of therapeutic agents while enabling targeted delivery and allowing efficient tumor imaging. In this review, we present fundamental aspects of peptide-based self-assembled nanofiber fabrication their applications in monotherapy/combinatorial chemo- and/or immuno-therapy to overcome multi-drug resistance. The role of self-assembled structures in targeted/stimuli-responsive (pH, enzyme and photo-responsive) drug delivery has been discussed along with the case studies. Further, recent advancements in peptide nanofibers in cancer diagnosis, imaging, gene therapy, and immune therapy along with regulatory obstacles towards clinical translation have been deliberated.

Apoptin and apoptotic protease-activating factor 1 plasmid-assisted multi-functional nanoparticles in hepatocellular carcinoma therapy

Cancer drugs usually have side effects in chemotherapy. Apoptin, a protein recognized by its good therapeutical effect on tumors and innocuous to body, is employed to treat hepatocellular carcinoma (HCC). As our previous data shown, the efficiency of apoptin protein might be limited by the protein of apaf-1. Therefore, we designed the multi-functional nanoparticles (MFNPs) encapsulating apoptin and apaf-1 plasmids by layer-by layer assembly. The NPs could release drugs into tumor site specifically and had good compatibility to normal cells and tissues. The groups of biotin, ε-polylysine, and nuclear localization signal in MFNPs conferred NPs the capabilities to enter cancer cells specifically, escape lysosome and enter the nucleus, respectively. In vitro inhibition experiment and in vivo anti-tumor therapy confirmed MFNPs as an excellent carrier to treat HCC. In addition, the dual-drug system was superior to any of the single-drug system. The mechanism analysis proved that supplement of the protein of apaf-1 might enhance apoptosome formation, causing the increase of therapeutical efficacy.

Peptide-Hydrogel Nanocomposites for Anti-Cancer Drug Delivery

Cancer is the second leading cause of death globally, but conventional anticancer drugs have side effects, mainly due to their non-specific distribution in the body in both cancerous and healthy cells. To address this relevant issue and improve the efficiency of anticancer drugs, increasing attention is being devoted to hydrogel drug-delivery systems for different kinds of cancer treatment due to their high biocompatibility and stability, low side effects, and ease of modifications. To improve the therapeutic efficiency and provide multi-functionality, different types of nanoparticles (NPs) can be incorporated within the hydrogels to form smart hydrogel nanocomposites, benefiting the advantages of both counterparts and suitable for advanced anticancer applications. Despite many papers on non-peptide hydrogel nanocomposites, there is limited knowledge about peptide-based nanocomposites, specifically in anti-cancer drug delivery. The aim of this short but comprehensive review is, therefore, to focus attention on the synergies resulting from the combination of NPs with peptide-based hydrogels. This review, which includes a survey of recent advances in this kind of material, does not aim to be an exhaustive review of hydrogel technology, but it instead highlights recent noteworthy publications and discusses novel perspectives to provide valuable insights into the promising synergic combination of peptide hydrogels and NPs for the design of novel anticancer drug delivery systems.

Hierarchical Assembly of Intrinsically Disordered Short Peptides

The understanding on how short peptide assemblies transit from disorder to order remains limited due to the lack of atomistic structures. Here we report cryo-EM structure of the nanofibers short intrinsically disordered peptides (IDPs). Upon lowering pH or adding calcium ions, the IDP transitions from individual nanoparticles to nanofibers containing an aromatic core and a disordered periphery comprised of 2 to 5 amino acids. Protonating the phosphate or adding more metal ions further assembles the nanofibers into filament bundles. The assemblies of the IDP analogs with controlled chemistry, such as phosphorylation site, hydrophobic interactions, and sequences indicate that metal ions interact with the flexible periphery of the nanoparticles of the IDPs to form fibrils and enhance the interfibrillar interactions to form filament bundles. Illustrating that an IDP self-assembles from disorder to order, this work offers atomistic molecular insights to understand assemblies of short peptides driven by noncovalent interactions.

Peptide Assemblies for Cancer Therapy

Supramolecular assemblies made by the self-assembly of peptides are finding an increasing number of applications in various fields. While the early exploration of peptide assemblies centered on tissue engineering or regenerative medicine, the recent development has shown that peptide assemblies can act as supramolecular medicine for cancer therapy. This review covers the progress of applying peptide assemblies for cancer therapy, with the emphasis on the works appeared over the last five years. We start with the introduction of a few seminal works on peptide assemblies, then discuss the combination of peptide assemblies with anticancer drugs. Next, we highlight the use of enzyme-controlled transformation or shapeshifting of peptide assemblies for inhibiting cancer cells and tumors. After that, we provide the outlook for this exciting field that promises new kind of therapeutics for cancer therapy.

Intra-Lysosomal Peptide Assembly for the High Selectivity Index against Cancer

Lysosomes remain powerful organelles and important targets for cancer therapy because cancer cell proliferation is greatly dependent on effective lysosomal function. Recent studies have shown that lysosomal membrane permeabilization induces cell death and is an effective way to treat cancer by bypassing the classical caspase-dependent apoptotic pathway. However, most lysosome-targeted anticancer drugs have very low selectivity for cancer cells. Here, we show intra-lysosomal self-assembly of a peptide amphiphile as a powerful technique to overcome this problem. We designed a peptide amphiphile that localizes in the cancer lysosome and undergoes cathepsin B enzyme-instructed supramolecular assembly. This localized assembly induces lysosomal swelling, membrane permeabilization, and damage to the lysosome, which eventually causes caspase-independent apoptotic death of cancer cells without conventional chemotherapeutic drugs. It has specific anticancer effects and is effective against drug-resistant cancers. Moreover, this peptide amphiphile exhibits high tumor targeting when attached to a tumor-targeting ligand and causes significant inhibition of tumor growth both in cancer and drug-resistant cancer xenograft models.

Platelet-mimicking supramolecular nanomedicine with precisely integrated prodrugs for cascade amplification of synergistic chemotherapy

Camptothecin (CPT) and cisplatin (Pt) have shown synergistic effects on a variety of cancers during preclinical and clinical studies. However, the ratio of the two drugs often could not be precisely regulated in different delivery systems, which hinders the desired synergistic effect. In addition, the low delivery efficiency of the two drugs to the tumor further impedes the ideal therapeutic outcomes. Herein, we report that a platelet-mimicking supramolecular nanomedicine (SN) could precisely control of the ratio of CPT and Pt with a high tumor accumulation rate for cascade amplification of synergistic chemotherapy. The SN was fabricated via the host-guest interaction between cucurbit[7]uril conjugated hyaluronic acid (HA-CB[7]) and adamantane (ADA) respectively functionalized CPT- and Pt-based prodrugs. The ratio of CPT and Pt in the SN could be facilely regulated by simply controlling the loading ratio, based on the strong binding affinity between CB[7] and ADA, and SN60 with 60% CPT and 40% Pt showed the highest synergistic effects on 4T1 cells. To improve the tumor accumulation efficiency of SN, 5,6-dimethylxanthenone-4-acetic acid (DMXAA, a tumor vasculature-disruptive agent) was loaded into the optimized SN and then coated with platelet membrane to yield platelet-mimicking supramolecular nanomedicine (D@SN-P). D@SN-P could first passively accumulate in tumors owing to the enhanced permeability and retention (EPR) effect after intravenous administration. The initially release of DMXAA from D@SN-P could induce tumor vascular disruption, and the resultant epithelial collagen exposure around the disrupted tumor vasculature provided a target for further recruitment of platelet-mimicking SN, leading to cascade amplification of tumor accumulation with synergistic chemotherapy. Hence, this platelet-mimicking supramolecular nanomedicine presents a universal supramolecular strategy to finely regulate the ratio of loaded pro-drugs, and improve the accumulation efficiency to amplify chemotherapy via platelet-mimics.

Enzymatic Self-Assembly of Adamantane-Peptide Conjugate for Combating Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus) remains a leading cause of bacterial infections. However, eradication of S. aureus infections with common antibiotics is increasingly difficult due to outbreaks of drug resistance. Therefore, new antibiotic classes and antibacterial strategies are urgently in demand. Herein, it is shown that an adamantane-peptide conjugate, upon dephosphorylation by alkaline phosphatase (ALP) constitutively expressed on S. aureus, generates fibrous assemblies in situ to combat S. aureus infection. By attaching adamantane to a phosphorylated tetrapeptide Nap-Phe-Phe-Lys-Tyr(H2 PO3 )-OH, the rationally designed adamantane-peptide conjugate Nap-Phe-Phe-Lys(Ada)-Tyr(H2 PO3 )-OH (Nap-FYp-Ada) is obtained. Upon bacterial ALP activation, Nap-FYp-Ada is dephosphorylated and self-assembles into nanofibers on the surface of S. aureus. As revealed by cell assays, the assemblies of adamantane-peptide conjugates interact with cell lipid membrane and thereby disrupt membrane integrity to kill S. aureus. Animal experiments further demonstrate the excellent potential of Nap-FYp-Ada in the treatment of S. aureus infection in vivo. This work provides an alternative approach to design antimicrobial agents.

Biopolymer-Based Nanogel Approach in Drug Delivery: Basic Concept and Current Developments

Due to their increased surface area, extent of swelling and active substance-loading capacity and flexibility, nanogels made from natural and synthetic polymers have gained significant interest in scientific and industrial areas. In particular, the customized design and implementation of nontoxic, biocompatible, and biodegradable micro/nano carriers makes their usage very feasible for a range of biomedical applications, including drug delivery, tissue engineering, and bioimaging. The design and application methodologies of nanogels are outlined in this review. Additionally, the most recent advancements in nanogel biomedical applications are discussed, with particular emphasis on applications for the delivery of drugs and biomolecules.

An injectable all-small-molecule dynamic metallogel for suppressing sepsis

All-small-molecule dynamic hydrogels have shown great promise in cell culture, tissue engineering, and controlled drug release. The further development of more kinds of all-small-molecule dynamic hydrogels is severely hindered by the lack of enough commensurate building blocks from nature and on the market. Inspired by the widely developed metal-organic framework structures, herein we report a facile fabrication of metallogels by direct gelation of small molecular compounds including aminoglycosides (AGs), 2,2'-bipyridine-4,4'-dicarboxaldehyde (BIPY), and metal ions via coordination interactions and Schiff base reactions. These prepared metallogels exhibited good biodegradability and biosafety, excellent conductivity, tunable mechanical properties and potent antibacterial activities both in vitro and in vivo. This study provides a new strategy for expanding the scope of all-small-molecule dynamic metallogels for various biomedical applications.

Application of molecular dynamics simulation in self-assembled cancer nanomedicine

Self-assembled nanomedicine holds great potential in cancer theragnostic. The structures and dynamics of nanomedicine can be affected by a variety of non-covalent interactions, so it is essential to ensure the self-assembly process at atomic level. Molecular dynamics (MD) simulation is a key technology to link microcosm and macroscale. Along with the rapid development of computational power and simulation methods, scientists could simulate the specific process of intermolecular interactions. Thus, some experimental observations could be explained at microscopic level and the nanomedicine synthesis process would have traces to follow. This review not only outlines the concept, basic principle, and the parameter setting of MD simulation, but also highlights the recent progress in MD simulation for self-assembled cancer nanomedicine. In addition, the physicochemical parameters of self-assembly structure and interaction between various assembled molecules under MD simulation are also discussed. Therefore, this review will help advanced and novice researchers to quickly zoom in on fundamental information and gather some thought-provoking ideas to advance this subfield of self-assembled cancer nanomedicine.

Advances in nuclei targeted delivery of nanoparticles for the management of cancer

A carrier is inserted into the appropriate organelles (nucleus) in successful medication transport, crucial to achieving very effective illness treatment. Cell-membrane targeting is the major focus of using nuclei to localize delivery. It has been demonstrated that high quantities of anticancer drugs can be injected directly into the nuclei of cancer cells, causing the cancer cells to die and increasing the effectiveness of chemotherapy. There are several effective ways to functionalize Nanoparticles (NPs), including changing their chemical makeup or attaching functional groups to their surface to increase their ability to target organelles. To cause tumor cells to apoptosis, released medicines must engage with molecular targets on particular organelles when their concentration is high enough. Targeted medication delivery studies will increasingly focus on organelle-specific delivery.

"Intercellular Mass Transport" Mimic Enables ASO Entry Completely into the Cell Nucleus for Enhanced Ischemia Therapy

Currently, the development of a new therapeutic technology is focused on antisense oligonucleotides (ASOs), where ASOs are used to complementarily pair with DNA, messenger RNA, or long noncoding RNA (lncRNA) to regulate the cell behavior by inhibiting the target gene expression. However, the targeted regulation toward nuclear genes still faces great challenges in ASO delivery for clinical applications, i.e., two essential criteria (high nuclear entry and delivery vehicle safety/simplification) generally compromise each other and are not simultaneously satisfactory. Herein, for the first time, inspired by "intercellular-mass-transport", we report an important discovery that the cell membrane of endothelial cells (ECs) serving as the biointerface enables ASOs to rapidly and completely enter the EC nucleus. Thereby, we innovatively fabricate a nanosystem only by sequential self-assembly of natural/off-the-shelf biomaterials to well overcome the above-mentioned contradiction. The efficacy is strikingly superior to that of the previous delivery vehicles. Furthermore, our technology is applied to successfully silence lncRNA MEG3 in the EC nucleus, significantly augmenting EC morphogenesis. More importantly, this nanosystem is applicable for in vivo intramuscular injection to enhance the therapeutic outcome in a critical limb ischemia mouse model. This work brings a new hope for the technological innovation of ASO nuclear delivery and opens a new avenue to explore natural/off-the-shelf materials for cargo delivery into subcellular compartments.

Enzyme-Instructed Peptide Assembly Favored by Preorganization for Cancer Cell Membrane Engineering

Innovative methods for engineering cancer cell membranes promise to manipulate cell-cell interactions and boost cell-based cancer therapeutics. Here, we illustrate an in situ approach to selectively modify cancer cell membranes by employing an enzyme-instructed peptide self-assembly (EISA) strategy. Using three phosphopeptides (pY1, pY2, and pY3) targeting the membrane-bound epidermal growth factor receptor (EGFR) and differing in just one phosphorylated tyrosine, we reveal that site-specific phosphorylation patterns in pY1, pY2, and pY3 can distinctly command their preorganization levels, self-assembling kinetics, and spatial distributions of the resultant peptide assemblies in cellulo. Overall, pY1 is the most capable of producing preorganized assemblies and shows the fastest dephosphorylation reaction in the presence of alkaline phosphatase (ALP), as well as the highest binding affinity for EGFR after dephosphorylation. Consequently, pY1 exhibits the greatest capacity to construct stable peptide assemblies on cancer cell membranes with the assistance of both ALP and EGFR. We further use peptide-protein and peptide-peptide co-assembly strategies to apply two types of antigens, namely ovalbumin (OVA) protein and dinitrophenyl (DNP) hapten respectively, on cancer cell membranes. This study demonstrates a very useful technique for the in situ construction of membrane-bound peptide assemblies around cancer cells and implies a versatile strategy to artificially enrich cancer cell membrane components for potential cancer immunotherapy.

A Cell Selective Fluoride-Activated MOF Biomimetic Platform for Prodrug Synthesis and Enhanced Synergistic Cancer Therapy

As a burgeoning bioorthogonal reaction, the fluoride-mediated desilylation is capable of prodrug activation. However, due to the reactions lack of cell selectivity and unitary therapy modality, this strongly impedes their biomedical applications. Herein, we construct a cancer cell-selective biomimetic metal-organic framework (MOF)-F platform for prodrug activation and enhanced synergistic chemodynamic therapy (CDT). With cancer cell membranes camouflage, the designed biomimetic nanocatalyst displays preferential accumulation to homotypic cancer cells. Then, pH-responsive nanocatalyst releases fluoride ions and ferric ions. For activation of our designed prodrug tert-butyldimethyl silyl (TBS)-hydroxycamptothecin (TBSO-CPT), fluoride ions can desilylate TBS and cleave the designed silyl ether linker to synthesize the OH-CPT (10-hydroxycamptothecin) drug molecule, which effectively kills cancer cells. Intriguingly, the bioorthogonal-synthesized OH-CPT drug upregulates intracellular H₂O₂ by activating nicotinamide adenine dinucleotide phosphate oxidase (NOX), amplifying the released iron induced Fenton reaction for synergistic CDT. Both in vitro and in vivo studies demonstrate our strategy presents a versatile fluoride-activated bioorthogonal catalyst for cancer cell-selective drug synthesis. Our work may accelerate the biomedical applications of fluoride-activated bioorthogonal chemistry.

Drug Self-Delivery Systems: Molecule Design, Construction Strategy, and Biological Application

Drug self-delivery systems (DSDSs) offer new ways to create novel drug delivery systems (DDSs). In typical DSDSs, therapeutic reagents are not considered passive cargos but active delivery agents of actionable targets. As an advanced drug delivery strategy, DSDSs with positive cooperativity of both free drugs and nanocarriers exhibit the clear merits of unprecedented drug-loading capacity, minimized systemic toxicity, and flexible preparation of nanoscale deliverables for passive targeted therapy. This review highlights the recent advances and future trends in DSDSs on the basis of two differently constructed structures: covalent and noncovalent bond-based DSDSs. Specifically, various chemical and architectural designs, fabrication strategies, and responsive and functional features are comprehensively discussed for these two types of DSDSs. In addition, additional comments on the current development status of DSDSs and the potential applications of their molecular designs are presented in the corresponding discussion. Finally, the promising potential of DSDSs in biological applications is revealed and the relationship between preliminary molecular design of DSDSs and therapeutic effects of subsequent DSDSs biological applications is clarified.

Self-Assembly of Short Amphiphilic Peptides and Their Biomedical Applications

A series of functional biomaterials with different sizes and morphologies can be constructed through self-assembly, among which amphiphilic peptide-based materials have received intense attention. One main possible reason is that the short amphiphilic peptides can facilitate the formation of versatile materials and promote their further applications in different fields. Another reason is that the simple structure of amphiphilic peptides can help establish the structure-function relationship. This review highlights the recent advances in the self-assembly of two typical peptide species, surfactant-like peptides (SLPs) and peptides amphiphiles (PAs). These peptides can self-assemble into diverse nanostructures. The formation of these different nanostructures resulted from the delicate balance of varied non-covalent interactions. This review embraced each non-covalent interaction and then listed the typical routes for regulating these non-covalent interactions, then realized the morphologies modulation of the self-assemblies. Finally, their applications in some biomedical fields, such as the stabilization of membrane proteins, templating for nanofabrication and biomineralization, acting as the antibacterial and antitumor agents, hemostasis, and synthesis of melanin have been summarized. Further advances in the self-assembly of SLPs and PAs may focus on the design of functional materials with targeted properties and exploring their improved properties.

Advanced nanomaterial for prostate cancer theranostics

Prostate cancer (PC) has the second highest incidence in men, according to global statistical data. The symptoms of PC in the early stage are not obvious, causing late diagnosis in most patients, which is the cause for missing the optimal treatment time. Thus, highly sensitive and precise early diagnosis methods are very important. Additionally, precise therapy regimens for good targeting and innocuous to the body are indispensable to treat cancer. This review first introduced two diagnosis methods, containing prostate-specific biomarkers detection and molecular imaging. Then, it recommended advanced therapy approaches, such as chemotherapy, gene therapy, and therapeutic nanomaterial. Afterward, we summarized the development of nanomaterial in PC, highlighting the importance of integration of diagnosis and therapy as the future direction against cancer.

Controlling Intracellular Enzymatic Self-Assembly of Peptide by Host-Guest Complexation for Programming Cancer Cell Death

Controlling the enzymatic reaction of macromolecules in living systems plays an essential role in determining the biological functions, which remains challenging in the synthetic system. This work shows that host-guest complexation could be an efficient strategy to tune the enzymatic self-assembly of the peptide. The formed host-guest complexation prevents the enzymatic kinetics of peptide assemblies on the cell surface and promotes cellular uptake of assemblies. For uptake inside cells, the host-guest complex undergoes dissociation in the acidic lysosome, and the released peptide further self-assembles inside the mitochondria. Accumulating assemblies at mitochondria induce the ferroptosis of cancer cells, resulting in cancer cell death in vitro and the tumor-bearing mice model. As the first example of using host-guest complexation to modulate the kinetics of enzymatic self-assembly, this work provides a general method to control enzymatic self-assembly in living cells for selective programming cancer cell death.

Advances in Antitumor Nano-Drug Delivery Systems of 10-Hydroxycamptothecin

10-Hydroxycamptothecin (HCPT) is a natural plant alkaloid from Camptotheca that shows potent antitumor activity by targeting intracellular topoisomerase I. However, factors such as instability of the lactone ring and insolubility in water have limited the clinical application of this drug. In recent years, unprecedented advances in biomedical nanotechnology have facilitated the development of nano drug delivery systems. It has been found that nanomedicine can significantly improve the stability and water solubility of HCPT. NanoMedicines with different diagnostic and therapeutic functions have been developed to significantly improve the anticancer effect of HCPT. In this paper, we collected reports on HCPT nanomedicines against tumors in the past decade. Based on current research advances, we dissected the current status and limitations of HCPT nanomedicines development and looked forward to future research directions.

Self-assembly hydrogels of therapeutic agents for local drug delivery

Advanced drug delivery systems are of vital importance to enhance therapeutic efficacy. Among various recently developed formulations, self-assembling hydrogels composed of therapeutic agents have shown promising potential for local drug delivery owing to their excellent biocompatibility, high drug-loading efficiency, low systemic toxicity, and sustained drug release behavior. In particular, therapeutic agents self-assembling hydrogels with well-defined nanostructures are beneficial for direct delivery to the target site via injection, not only improving drug availability, but also extending their retention time and promoting cellular uptake. In brief, the self-assembly approach offers better opportunities to improve the precision of pharmaceutical treatment and achieve superior treatment efficacies. In this review, we intend to cover the recent developments in therapeutic agent self-assembling hydrogels. First, the molecular structures, self-assembly mechanisms, and application of self-assembling hydrogels are systematically outlined. Then, we summarize the various self-assembly strategies, including the single therapeutic agent, metal-coordination, enzyme-instruction, and co-assembly of multiple therapeutic agents. Finally, the potential challenges and future perspectives are discussed. We hope that this review will provide useful insights into the design and preparation of therapeutic agent self-assembling hydrogels.

Self-Assembly of Small Organic Molecules into Luminophores for Cancer Theranostic Applications

Self-assembled biomaterials have been widely explored for real-time fluorescence imaging, imaging-guided surgery, and targeted therapy for tumors, etc. In particular, small molecule-based self-assembly has been established as a reliable strategy for cancer theranostics due to the merits of small-sized molecules, multiple functions, and ease of synthesis and modification. In this review, we first briefly introduce the supramolecular chemistry of small organic molecules in cancer theranostics. Then, we summarize and discuss advanced small molecule-based self-assembly for cancer theranostics based on three types, including peptides, amphiphilic molecules, and aggregation-induced emission luminogens. Finally, we conclude with a perspective on future developments of small molecule-based self-assembled biomaterials integrating diagnosis and therapy for biomedical applications. These applications highlight the opportunities arising from the rational design of small organic molecules with self-assembly properties for precision medicine.

Research Progress of Conjugated Nanomedicine for Cancer Treatment

The conventional cancer therapeutic modalities include surgery, chemotherapy and radiotherapy. Although immunotherapy and targeted therapy are also widely used in cancer treatment, chemotherapy remains the cornerstone of tumor treatment. With the rapid development of nanotechnology, nanomedicine is believed to be an emerging field to further improve the efficacy of chemotherapy. Until now, there are more than 17 kinds of nanomedicine for cancer therapy approved globally. Thereinto, conjugated nanomedicine, as an important type of nanomedicine, can not only possess the targeted delivery of chemotherapeutics with great precision but also achieve controlled drug release to avoid adverse effects. Meanwhile, conjugated nanomedicine provides the platform for combining several different therapeutic approaches (chemotherapy, photothermal therapy, photodynamic therapy, thermodynamic therapy, immunotherapy, etc.) with the purpose of achieving synergistic effects during cancer treatment. Therefore, this review focuses on conjugated nanomedicine and its various applications in synergistic chemotherapy. Additionally, the further perspectives and challenges of the conjugated nanomedicine are also addressed, which clarifies the design direction of a new generation of conjugated nanomedicine and facilitates the translation of them from the bench to the bedside.

An injectable co-assembled hydrogel blocks reactive oxygen species and inflammation cycle resisting myocardial ischemia-reperfusion injury

The overproduction of reactive oxygen species (ROS) and burst of inflammation following cardiac ischemia-reperfusion (I/R) are the leading causes of cardiomyocyte injury. Monotherapeutic strategies designed to enhance anti-inflammatory or anti-ROS activity explicitly for treating I/R injury have demonstrated limited success because of the complex mechanisms of ROS production and induction of inflammation. Intense oxidative stress leads to sustained injury, necrosis, and apoptosis of cardiomyocytes. The damaged and necrotic cells can release danger-associated molecular patterns (DAMPs) that can cause the aggregation of immune cells by activating Toll-like receptor 4 (TLR4). These immune cells also promote ROS production by expressing NADPH oxidase. Finally, ROS production and inflammation form a vicious cycle, and ROS and TLR4 are critical nodes of this cycle. In the present study, we designed and prepared an injectable hydrogel system of EGCG@Rh-gel by co-assembling epigallocatechin-3-gallate (EGCG) and the rhein-peptide hydrogel (Rh-gel). The co-assembled hydrogel efficiently blocked the ROS-inflammation cycle by ROS scavenging and TLR4 inhibition. Benefited by the abundant noncovalent interactions of π-π stacking and hydrogen bonding between EGCG and Rh-gel, the co-assembled hydrogel had good mechanical strength and injectable property. Following the injection EGCG@Rh-gel into the damaged region of the mice's heart after I/R, the hydrogel enabled to achieve long-term sustained release and treatment, improve cardiac function, and significantly reduce the formation of scarring. Further studies demonstrated that these beneficial outcomes arise from the reduction of ROS production, inhibition of inflammation, and induction of anti-apoptosis in cardiomyocytes. Therefore, EGCG@Rh-gel is a promising drug delivery system to block the ROS-inflammation cycle for resisting myocardial I/R injury. STATEMENT OF SIGNIFICANCE: 1. Monotherapeutic strategies designed to enhance anti-inflammatory or anti-ROS effects for treating I/R injury have demonstrated limited success because of the complex mechanisms of ROS and inflammation. 2. ROS production and inflammation form a vicious cycle, and ROS and TLR4 are critical nodes of this cycle. 3. Here, we designed an injectable hydrogel system of EGCG@Rh-gel by co-assembling epigallocatechin-3-gallate (EGCG) and a rhein-peptide hydrogel (Rh-gel). EGCG@Rh-gel efficiently blocked the ROS-inflammation cycle by ROS scavenging and TLR4 inhibition. 4. EGCG@Rh-gel achieved long-term sustained release and treatment, improved cardiac function, and significantly reduced the formation of scarring after I/R. 5. The beneficial outcomes arise from reducing ROS production, inhibiting inflammation, and inducing anti-apoptosis in cardiomyocytes.

Recent Progress of Rare Earth Doped Hydroxyapatite Nanoparticles: Luminescence Properties, Synthesis and Biomedical Applications

Hydroxyapatite nanoparticles (HAP NPs) are host materials and can be modified with various substrates and dopants. Among them, rare earth (RE) ions doped HAP NPs have gathered attention due to their unique physicochemical and imaging properties. Compared to other fluorescence probes, RE-doped HAP NPs display advantages in high brightness, high contrast, photostability, nonblinking, and narrow emission bands. Meanwhile, their intrinsic features (composition, morphology, size, crystallinity, and luminescence intensity) can be adjusted by changing the dopant ratio, synthesizing temperature, reaction time, and techniques. And they have been used in various biomedical applications, including imaging probe, drug delivery, bone tissue engineering, and antibacterial studies. This review surveys the luminescent properties, fluorescence enhancement, synthetic methods, and biocompatibility of various RE-doped HAP NPs consolidated from different research works, for their employments in biomedical applications. For this literature review, an electronic search was conducted in the Pubmed, Web of Science, Google Scholar, Scopus and SciFinder databases, using the keywords: hydroxyapatite, rare earth, lanthanide, fluorescence, and imaging. Literature searches of English-language publications from 1979 with updates through April, 2022, and a total of 472 potential papers were identified. In addition, a few references were located by noting their citation in other studies reviewed. STATEMENT OF SIGNIFICANCE: Hydroxyapatite nanoparticles (HAP NPs) have a broad range of promising biological applications. Although prospective biomedical applications are not limited to rare earth-doped hydroxyapatite nanoparticles (RE-doped HAP NPs), some cases do make use of the distinctive features of RE-elements to achieve the expected functions for HAP families. This review surveys the luminescent properties, synthetic methods, and biocompatibility of various RE-doped HAP NPs consolidated from different research works, for their employments in biomedical applications, including imaging probe, drug delivery, bone tissue repair and tracking, and anti-bacteria. Overall, we expect to shed some light on broadening the research and application of RE-doped HAP NPs in biomedical field.

Enzyme-instructed self-assembly (EISA) assists the self-assembly and hydrogelation of hydrophobic peptides

Enzyme-instructed self-assembly (EISA) has several advantages in the preparation of supramolecular self-assembly materials for biomedical applications. In this study, we demonstrated that the enzyme-instructed self-assembly (EISA) strategy could assist the self-assembly and hydrogelation of two hydrophobic and bioactive peptides, tyroservatide (YSV) and laminin pentapeptide (YIGSR). We first synthesized the peptide derivatives of Nap-GFFYSV (peptide 1) and Nap-GFFYIGSR (peptide 2) and found that both peptides could not self-assemble into hydrogels due to their poor solubility. We therefore designed the phosphorylated precursors of the two hydrophobic peptides, Nap-GFFpYSV (precursor 1) and Nap-GFFpYIGSR (precursor 2), respectively, which had good solubility and can be dephosphorylated by alkaline phosphatase (ALP) to form supramolecular hydrogels. In addition, we found that the EISA could also occur on the surface of cells that overexpress ALP. The EISA strategy was a powerful method to generate hydrogels of hydrophobic compounds. We envision the big promise of the strategy in the preparation of biomaterials and nanomaterials of hydrophobic bioactive molecules.

Orthogonal Design of Supramolecular Prodrug Vesicles via Water-Soluble Pillar[5]arene and Betulinic Acid Derivative for Dual Chemotherapy

Supramolecular prodrug vesicles with efficient property for dual chemotherapy have been successfully constructed based on the orthogonal self-assembly between a water-soluble pillar[5]arene host (WP5) and a betulinic acid guest (BA-D) as well as doxorubicin (DOX). Under the acidic microenvironment of cancer cells, both the encapsulated anticancer drug DOX and prodrug BA-D can be effectively released from DOX-loaded WP5⊃BA-D prodrug vesicles for combinational chemotherapy. Furthermore, bioexperiments indicate that DOX-loaded prodrug vesicles can obviously enhance the anticancer efficiency based on the cooperative effect of DOX and BA-D, while remarkably reducing the systematic toxicity in tumor-mice, displaying great potential applications in combinational chemotherapy for cancer treatments.

Quantitative Analysis of the Interactions of Metal Complexes and Amphiphilic Systems: Calorimetric, Spectroscopic and Theoretical Aspects

Metals and metal-based compounds have many implications in biological systems. They are involved in cellular functions, employed in the formation of metal-based drugs and present as pollutants in aqueous systems, with toxic effects for living organisms. Amphiphilic molecules also play important roles in the above bio-related fields as models of membranes, nanocarriers for drug delivery and bioremediating agents. Despite the interest in complex systems involving both metal species and surfactant aggregates, there is still insufficient knowledge regarding the quantitative aspects at the basis of their binding interactions, which are crucial for extensive comprehension of their behavior in solution. Only a few papers have reported quantitative analyses of the thermodynamic, kinetic, speciation and binding features of metal-based compounds and amphiphilic aggregates, and no literature review has yet addressed the quantitative study of these complexes. Here, we summarize and critically discuss the recent contributions to the quantitative investigation of the interactions of metal-based systems with assemblies made of amphiphilic molecules by calorimetric, spectrophotometric and computational techniques, emphasizing the unique picture and parameters that such an analytical approach may provide, to support a deep understanding and beneficial use of these systems for several applications.

Sequential Drug Delivery in Targeted Cancer Therapy

Cancer is a major public health problem and one of the leading causes of death. However, traditional cancer therapy may damage normal cells and cause side effects. Many targeted drug delivery platforms have been developed to overcome the limitations of the free form of therapeutics and biological barriers. The commonly used cancer cell surface targets are CD44, matrix metalloproteinase-2, folate receptors, etc. Once the drug enters the cell, active delivery of the drug molecule to its final destination is still preferred. The subcellular targeting strategies include using glucocorticoid receptors for nuclear targeting, negative mitochondrial membrane potential and N-acetylgalactosaminyltransferase for Golgi apparatus targeting, etc. Therefore, the most effective way to deliver therapeutic agents is through a sequential drug delivery system that simultaneously achieves cellular- and subcellular-level targeting. The dual-targeting delivery holds great promise for improving therapeutic effects and overcoming drug resistance. This review classifies sequential drug delivery systems based on final targeted organelles. We summarize different targeting strategies and mechanisms and gave examples of each case.

Supramolecular Nanomedicines of In-Situ Self-Assembling Peptides

Nanomedicines provide distinct clinical advantages over traditional monomolecular therapeutic and diagnostic agents. Supramolecular nanomedicines made from in-situ self-assembling peptides have emerged as a promising strategy in designing and fabricating nanomedicines. In-situ self-assambly (SA) allows the combination of nanomedicines approach with prodrug approach, which exhibited both advantages of these strategies while addressed the problems of both and thus receiving more and more research attention. In this review, we summarized recently designed supramolecular nanomedicines of in-situ SA peptides in the manner of applications and design principles, and the interaction between the materials and biological environments was also discussed.

Multifunctional MnO2/Ag3SbS3 Nanotheranostic Agent for Single-Laser-Triggered Tumor Synergistic Therapy in the NIR-II Biowindow

Regulating the level of reactive oxygen species (ROS) in a tumor is an efficient and innovative anticancer strategy. However, the therapeutic efficacy of ROS-based therapies, such as chemodynamic therapy (CDT) and photodynamic therapy (PDT), offers finite outcomes due to the oxygen dependence and limited concentration of hydrogen peroxide (H₂O₂) and overexpression of glutathione (GSH) within the tumor microenvironment (TME), so a single therapeutic strategy is insufficient to completely eliminate tumors. Therefore, we demonstrated an omnipotent nanoplatform MnO₂/Ag₃SbS₃ (abbreviated as MA) with strong optical absorbance in the NIR-II biowindow and oxygen self-sufficient ROS-mediated ability, which not only relieves tumor hypoxia significantly but also enhances the photothermal therapy (PTT)/PDT/CDT efficacy. By 1064 nm laser irradiation, MnO₂/Ag₃SbS₃ nanoparticles (NPs) reveal a favorable photothermal conversion efficiency of 23.15% and achieve a single-laser-triggered NIR-II PTT/PDT effect, resulting in effective tumor elimination. Once internalized into the tumor, MnO₂/Ag₃SbS₃ NPs will be degraded to Mn²⁺ and Ag₃SbS₃. The released Ag₃SbS₃ NPs as a NIR-II phototherapy agent could be utilized for photoacoustic imaging-guided NIR-II PDT/PTT. Mn²⁺ could be used as a Fenton-like catalyst to continuously catalyze endogenous H₂O₂ for generating highly virulent hydroxyl radicals (^•OH) for CDT and O₂ for PDT, enhancing the efficiency of PDT and CDT, respectively. Meanwhile, Mn²⁺ realizes magnetic resonance imaging-guided accurate tumor therapy. Moreover, the MnO₂/Ag₃SbS₃ NPs could deplete intracellular GSH in TME to promote oxidative stress of the tumor, further strengthening ROS-mediated antitumor treatment efficacy. Overall, this work presents a distinctive paradigm of TME-responsive PDT/CDT/PTT in the second near-infrared biowindow by depleting GSH and decomposing H₂O₂ for efficient and precise cancer treatment.