Metal-Coordinated Supramolecular Self-Assemblies for Cancer Theranostics

pH-driven butterfly effect for cascade-amplified tumor therapy based on thalidomide coordinated Fe-HMME nanoplatform

A promising approach for treating intractable cancers has been presented by photodynamic therapy (PDT). However, the limited penetration depth of PDT and suboptimal monotherapy efficacy of PDT significantly restrict its clinical applications. In this study, we constructed an acidic tumor microenvironment (TME)-activated carrier-free nanoplatform (HMME-Fe-Thal, abbreviated as HFT) through self-assembly of iron ions, photosensitizer hematoporphyrinmonomethyl ether (HMME) and anti-angiogenesis drug thalidomide (Thal). Near infrared (NIR) triggers PDT behavior before the degradation of the HFT nanoplatform. Subsequently, the HFT nanoplatform degrades, releasing Thal for chemotherapy, iron ions for chemodynamic therapy (CDT), which reinforce the therapeutic benefits of PDT synergistically. Moreover, the iron ions released by HFT degradation turn on the MRI signal, which can suggest the most appropriate time for PDT, divide the treatment into two stages (First-stage: PDT, Second-stage: CDT/chemotherapy), and gradually achieve cascade-amplified tumor therapy. In this sense, HFT modulates TME and leads to a "butterfly effect" of CDT/chemotherapy/glutathione (GSH) depletion for enhanced PDT efficacy. This strategy compensates the deficient shadow penetration and poor treatment efficacy from PDT monotherapy. This work presents the selection and rational design of HFT constructed by endogenous components for tumor regression, and greatly push nanomaterials towards the development of PDT application.

How Traditional Chinese Medicine Can Play a Role In Nanomedicine? A Comprehensive Review of the Literature

Traditional Chinese medicine (TCM), a time-honored practice rooted in natural therapeutics, has served as a cornerstone in safeguarding human health across millennia, aiding in disease mitigation and life vitality preservation. However, many TCM active ingredients suffer from poor solubility, low bioavailability, uncertain toxicity and weak targeting ability. Nanomedicine represents a modern scientific frontier, emerging from the precise engineering of unique nanoscale characteristics, with extensive applications encompassing targeted therapeutic delivery and diverse biomedical fields. Although TCM and nanomedicine diverge fundamentally in historical origins and disciplinary foundations, growing investigations demonstrate their synergistic potential. In this review, nanosized TCM has been revealed as an innovative therapeutic strategy with significant clinical value. Based on the biological activities and structural characteristics of TCM active ingredients, we classify them into two categories: natural nanostructured formulations for TCM and nano-drug delivery systems for TCM. A systematic and comprehensive analysis of preparations specific and functions to two classes of TCM nanomedicines is highlighted. Insights into the advantage of TCM nanomedicines are also introduced. Subsequently, the applications of TCM nanomedicines in the biomedical treatment, including anti-cancer, anti-inflammation and anti-bacterial are summarized. Finally, challenges and future research directions are emphasized, aiming to offer guidance for the modernization of TCM nanomedicines.

Controlling the Morphology and Orientation of the Helical Self-Assembly of Pyrazine Derivatives by Tuning Hydration Shells

A combination of density functional theory (DFT) and classical molecular dynamics simulations is performed to unveil the guiding force in the self-assembly process of the pyrazine-based biopolymers to helical nanostructures. The highlight of the study shows the decisive role of the solvent-ligand H-bonding and the inter-molecular pi-pi stacking not only ensures the unidirectional packing of the helical structure but also the rotation of left-handed to the right-handed helical structure of the molecule. This transition is supported by the bulk release of the "ordered" water molecules. The extent of this bonding can be tuned by the temperature, concentration, and type of the metal ions. Smaller ions like Na+ and Al3+ destroy the structure, whereas bigger ions like Zn2+, Ni2+, and Au3+ preserve and rotate the structure according to their concentration. The interaction energy between the pyrazine derivatives is found to be high (-9000 kJ mol-1) for right-handed rotation of the helix, which increases further with the addition of D-histidine, forming a superhelical structure (-10300 kJ mol-1). The insights gained from this work can be used to generate nanostructures of desired morphology.

Iron-Doxorubicin Hyaluronan Nanogel as an Effective Targeted Chemotherapy with Modulated Cardiotoxicity

The complex of doxorubicin (Dox) and intracellular iron in cardiomyocytes generates reactive oxygen species (ROS), contributing to commonly observed cardiotoxicity. To enhance the anticancer potency and minimize the cardiotoxicity, here Dox was formulated into a hyaluronan (HA) nanogel using ferric ion (Fe3+) coordination to control the intracellular distribution and release of Dox. Taking advantage of the paramagnetic properties of iron and the fluorescence of Dox, we conveniently monitored the targeted delivery of the HA@Dox nanogel in murine breast tumors through both T1-weighted magnetic resonance imaging and fluorescence imaging. Compared with free Dox, HA@Dox nanogel affords a CD44-targeted delivery, lysosomal distribution, pH-responsive release, and significant tumor inhibition. Mechanistically, the lysosome-enriched HA@Dox produces ROS, causing lysosomal membrane permeabilization, which further promotes the intracellular Dox distribution. This HA@Dox nanogel not only provides a facile cancer-targeted delivery but also successfully relieves Dox toxicity, representing a potent delivery system for Dox.

Metal-phenolic network crosslinked nanogel with prolonged biofilm retention for dihydroartemisinin/NIR synergistically enhanced chemodynamic therapy

Chemodynamic therapy (CDT) is emerging as a promising treatment for biofilm infections. However, its effectiveness is significantly hindered by several factors: the body's stable temperature, a limited supply of Fe2+ ions, and inadequate endogenous levels of H2O2 at the infection sites. Herin, our study introduces MPN-crosslinked hyaluronic acid (HA) nanogels as an effective strategy for treating biofilm-associated infections. The DHA@HA-TA/Fe (DHTF) nanogel is synthesized through the coordination reaction between Fe2+ ions and tannic acid (TA)-modified HA, with dihydroartemisinin (DHA) encapsulated within the structure. DHTF exhibits pH-/hyaluronidase-responsiveness in the biofilm infection microenvironment, enabling sustained release of DHA as a substitute for H2O2 and Fe2+ for CDT. The incorporation of Fe2+/TA-based MPN and DHA within the nanogels enables photothermal/DHA dually-enhanced CDT, facilitating efficient disruption of biofilm matrices and bacterial eradication through boosting reactive oxygen species production. In vivo studies demonstrate that DHTF exhibit prolonged retention within biofilms. This ensures a sustained release of therapeutic agents and continuous anti-biofilm activity. Eventually, both in vitro and in vivo evaluations consistently confirm the significant anti-biofilm capacity of DHTF. Our findings highlight the potential of DHTF as a promising nanomedicine for biofilm-related infections, offering efficient treatment strategies that could improve clinical management of these challenging conditions.

Facile Synthesis of Fe-Based Metal-Quinone Networks for Mutually Enhanced Mild Photothermal Therapy and Ferroptosis

Mild photothermal therapy (MPTT) has emerged as a promising therapeutic modality for attenuating thermal damage to the normal tissues surrounding tumors, while the heat-induced upregulation of heat shock proteins (HSPs) greatly compromises the curative efficacy of MPTT by increasing cellular thermo-tolerance. Ferroptosis has been identified to suppress the overexpression of HSPs by the accumulation of lipid peroxides and reactive oxygen species (ROS), but is greatly restricted by overexpressed glutathione (GSH) in tumor microenvironment and undesirable ROS generation efficiency. Herein, a synergistic strategy based on the mutual enhancement of MPTT and ferroptosis is proposed for cleaving HSPs to recover tumor cell sensitivity. A facile method for fabricating a series of Fe-based metal-quinone networks (MQNs) by coordinated assembly is proposed and the representative FTP MQNs possess high photothermal conversion efficiency (69.3 %). Upon 808 nm laser irradiation, FTP MQNs not only trigger effective MPTT to induce apoptosis but more significantly, potentiate Fenton reaction and marked GSH consumption to boost ferroptosis, and the reinforced ferroptosis effect in turn can alleviate the thermal resistance by declining the HSP70 defense and reducing ATP levels. This study provides a valuable rationale for constructing a large library of MQNs for achieving mutual enhancement of MPTT and ferroptosis.

Metal‐coordinated amino acid/peptide/protein‐based supramolecular self‐assembled nanomaterials for anticancer applications

Biomolecules with metals can form supramolecular nanomaterials through coordination assembly, opening new avenues for cancer theranostics and bringing unique insights into personalized nanomedicine. These biomaterials have been considered versatile and innovative nanoagents due to their structure‒function control, biological nature, and simple preparation methods. This review article summarized the recent developments in multicomponent nanomaterials formed from metal coordination interactions with amino acids, peptides, and proteins, together with anticancer drugs, for cancer theranostics. We discussed the role of functional groups anchored in building blocks for coordination interactions, and subsequently, the types of interactions were examined from a structure‒function perspective. Amino acids with different metals and anticancer drugs forming supramolecular nanomaterials and their anticancer mechanisms were highlighted. Peptides with different metals and anticancer drugs, proteins with metals and anticancer drugs used for material formations, and anticancer activity have been discussed. Ultimately, the conclusion and future outlook for multicomponent supramolecular nanomaterials offer fundamental insights into fabrication design and precision medicine.

Assembling a new generation of radiopharmaceuticals with supramolecular theranostics

Supramolecular chemistry has been used to tackle some of the major challenges in modern science, including cancer therapy and diagnosis. Supramolecular platforms provide synthetic flexibility, rapid generation through self-assembly, facile labelling, unique topologies, tunable reversibility of the enabling noncovalent interactions, and opportunities for host-guest chemistry and mechanical bonding. In this Review, we summarize recent advances in the design and radiopharmaceutical application of discrete self-assembled coordination complexes and mechanically interlocked molecules - namely, metallacages and rotaxanes, respectively - as well as in situ-forming supramolecular aggregates, specifically pinpointing their potential as next-generation radiotheranostic agents. The outlook of such supramolecular constructs for potential applications in the clinic is discussed.

An encounter between metal ions and natural products: natural products-coordinated metal ions for the diagnosis and treatment of tumors

Natural products-coordinated metal ions to form the nanomedicines are in the spotlight for cancer therapy. Some natural products could be coordinated with metal ions forming nanomedicines via simple and green environmental self-assembly, which not only improved the bioavailability of natural products, but also conferred multiple therapeutic modalities and multimodal imaging. On the one hand, in the weak acidity, glutathione (GSH) and hydrogen peroxide (H2O2) overexpression of tumor microenvironment (TME), such carrier-free nanomedicines could be further enhanced the therapeutic effect via optimizing the species of metal ions. On the other hand, nanomedicines could exert the precise treatment of tumor under the guidance of multiple imaging. Hence, this review summarized the research progress in recent years on the application of natural product-coordinated metal ions in cancer therapy. In addition, the prospects and challenges for the application of natural product-coordinated metal ions were discussed, especially how to improve targeting ability and stability and assess the safety of metal ions, so as to facilitate the clinical translation and application of natural product-coordinated metal ions nanomedicines.

Optimization of band structure by facet engineering to enhance photocatalytic/photothermal synergistic therapy of cobalt sulfide nanosheets

With the rapid development of optics and nanotechnology, optical therapy is recognized as a potential strategy to combat bacterial drug resistance. Unfortunately, the limitation of band structure on the therapeutic effect of photocatalytic nano-antimicrobial materials has become a major challenge in the development of optical therapy. Here, Co9S8 and Co9S8-T200 were prepared by facet engineering design with major exposed facets (311) and (222), respectively. The experimental results demonstrate that the antimicrobial ability of Co9S8-T200 was significantly higher than that of Co9S8 under the excitation of near-infrared light. Theoretical calculations show that the (222) facets can modulate the d-band center of Co9S8-T200 closer to the Fermi energy level. This promotes the binding of the intermediate to the active site. The strong adsorption capacity for O2 and H2O and the high efficiency of electron-hole pair separation facilitate the production of reactive oxygen species dominated by singlet oxygen, and the photocatalytic therapy is effectively enhanced. In addition, Co9S8-T200 has a narrow bandgap to promote photothermal conversion efficiency and light absorption capacity and exhibits excellent photothermal therapy. This work expands new ideas for the development of superior optical antimicrobial agents with synergistic photothermal and photocatalytic therapy.

Enzyme-Mimetic, Cascade Catalysis-Based Triblock Polypeptide-Assembled Micelles for Enhanced Chemodynamic Therapy

Peptides and their conjugates are appealing as molecular scaffolds for constructing supramolecular biomaterials from the bottom up. Through strategic sequence design and interaction modulation, these peptides can self-assemble into diverse nanostructures that can, in turn, mimic the structural and catalytic functions of contemporary proteins. Here, inspired by the histidine brace active site identified in the metalloenzyme, we developed a triblock polypeptide with a hydrophobic polyleucine segment, a hydrophilic polylysine segment, and a terminal oligohistidine segment. This polypeptide demonstrates tunable and adaptive self-assembly morphologies. Moreover, copper ions can interact with the oligohistidine chelator and mediate the supramolecular assembly, generating metal-ligand centers for redox flow. The triblock polypeptide-based peptide micelles show Fenton-type activity with high substrate affinity when coassembled with copper ions. We have also engineered therapeutic micelles by coassembling two polypeptides, one integrated with copper ions and the other conjugated with glucose oxidase. This coassembled nanoplatform shows high in vitro and in vivo antitumor efficacy through a mechanism that combines triggered starvation and chemodynamic therapy. The versatility of this polypeptide sequence, which is compatible with various metal ions and functional ligands, paves the way for a broad spectrum of therapeutic and diagnostic applications.

Engineered manganese-BODIPY coordinated nanoadjuvants for enhanced NIR-II photo-metalloimmunotherapy

Immunotherapy, a pivotal and promising approach for tumor treatment, has demonstrated prominent clinical efficacy. However, its effectiveness is often impeded by insufficient antitumor immune responses attributed to the immunosuppressive tumor microenvironment (TME). The combination of immune activation through the stimulator of interferon genes (STING) pathway and phototherapy holds great potential for surmounting this challenge in advanced tumor immunotherapy. Herein, a novel manganese-boosted NIR-II photo-metalloimmunotherapy is proposed to synergistically enhance antitumour efficacy by fabricating Mn2+-BODIPY-based coordinated photo-immune nanoadjuvants (BMR), modified with tumor-targeted peptide cRGD. The obtained BMR could effectively deliver Mn2+ to tumor sites, and immunogenic cell death (ICD) was evoked by localized photothermal ablation of tumors using NIR-II laser irradiation. Simultaneously, pH-responsive release of Mn2+ would trigger the activation of STING pathway to promote the production of type I interferons (I-IFNs), significantly facilitating the maturation of dendritic cells (DCs) and polarization of macrophages to M1 phenotypes. Furthermore, by synergistically initiating systematic and robust antitumour immune responses, the BMR-mediated NIR-II photo-metalloimmunotherapy achieved remarkable therapeutic efficacy against both primary and lung metastasis of B16F10 tumors. Overall, in light of the versatile functionalities and synthetic flexibility of coordinated nanoadjuvants, formulated with photofunctional ligands and diverse metal ions, this work provides new insights into the design of metal coordination nanomedicine for effective antitumor photo-metalloimmunotherapy.

Metal-ligand cross-link strategy engineered iron-doped dopamine-based superstructure as peroxidase-like nanozymes for detection of glucose

Nanozymes are nanomaterials with mimetic enzyme properties and the related research has attracted much attention. It is of great value to develop methods to construct nanozymes and to study their application in bioanalysis. Herein, the metal-ligand cross-linking strategy was developed to fabricate superstructure nanozymes. This strategy takes advantage of being easy to operate, adjustable, cheap, and universal. The fabricated superstructure nanozymes possess efficient peroxidase-like catalytic activity. The enzyme reaction kinetic tests demonstrated that for TMB and H2O2, the Km is 0.229 and 1.308 mM, respectively. Furthermore, these superstructure nanozymes are applied to highly efficient and sensitive detection of glucose. The linear range for detecting glucose is 20-2000 μM, and the limit of detection is 17.5 μM. Furthermore, mechanistic research illustrated that this integrated system oxidizes glucose to produce hydrogen peroxide and further catalyzes the production of ·OH and O2·-, which results in a chromogenic reaction of oxidized TMB for the detection of glucose. This work could not only contribute to the development of efficient nanozymes but also inspire research in the highly sensitive detection of other biomarkers.

Metal-Organic Nanomaterials for Tumor Metabolic Blockade and Image to Increase Tumor Therapy

The abnormal energy metabolism level of a tumor reduces the efficiency of chemotherapy. Metal-organic nanomaterials (MONs) with high drug loading efficiency, easy processes of synthesis, and controlled drug release have shown great potential in metabolic blocking and enhancement of tumor therapy. These metal-organic nanomedicines have been reported to modulate glycolysis or oxidative phosphorylation to provide monotherapy or combined therapies in tumorous treatments. In addition, the encapsulation or coordination of fluorescent dyes into MONs endowed them with the imaging ability of tumor metabolism. Herein, this Perspective summarizes the progress of MONs as therapeutic agents or imaging probes for application during tumor metabolic blocking or imaging, providing solid inspiration for biomedical applications of effective biomaterials. In addition, the current drawbacks of MONs for further biological applications in the future were discussed, giving stimulation of innovation and development in biomedical applications of MONs.

Carrier-Free Nanodrugs: From Bench to Bedside

Carrier-free nanodrugs with extraordinary active pharmaceutical ingredient (API) loading (even 100%), avoidable carrier-induced toxicity, and simple synthetic procedures are considered as one of the most promising candidates for disease theranostics. Substantial studies and the commercial success of "carrier-free" nanocrystals have demonstrated their strong clinical potential. However, their practical translations remain challenging and are impeded by unpredictable assembly processes, insufficient delivery efficiency, and an unclear in vivo fate. In this Perspective, we systematically outline the contemporary and emerging carrier-free nanodrugs based on diverse APIs, as well as highlight their opportunities and challenges in clinical translation. Looking ahead, further improvements in design and preparation, drug delivery, in vivo efficacy, and safety of carrier-free nanomedicines are essential to facilitate their translation from the bench to bedside.

Fluorinated macromolecular amphiphiles as prototypic molecular drones

The advent of drones has revolutionized various aspects of our lives, and in the realm of biological systems, molecular drones hold immense promise as "magic bullets" for major diseases. Herein, we introduce a unique class of fluorinated macromolecular amphiphiles, designed in the shape of jellyfish, serving as exemplary molecular drones for fluorine-19 MRI (19F MRI) and fluorescence imaging (FLI)-guided drug delivery, status reporting, and targeted cancer therapy. Functioning akin to their mechanical counterparts, these biocompatible molecular drones autonomously assemble with hydrophobic drugs to form uniform nanoparticles, facilitating efficient drug delivery into cells. The status of drug delivery can be tracked through aggregation-induced emission (AIE) of FLI and 19F MRI. Furthermore, when loaded with a heptamethine cyanine fluorescent dye IR-780, these molecular drones enable near-infrared (NIR) FL detection of tumors and precise delivery of the photosensitizer. Similarly, when loaded with doxorubicin (DOX), they enable targeted chemotherapy with fluorescence resonance energy transfer (FRET) FL for real-time status updates, resulting in enhanced therapeutic efficacy. Compared to conventional drug delivery systems, molecular drones stand out for their simplicity, precise structure, versatility, and ability to provide instantaneous status updates. This study presents prototype molecular drones capable of executing fundamental drone functions, laying the groundwork for the development of more sophisticated molecular machines with significant biomedical implications.

Recent Advances in Research from Nanoparticle to Nano-Assembly: A Review

The careful arrangement of nanomaterials (NMs) holds promise for revolutionizing various fields, from electronics and biosensing to medicine and optics. This review delves into the intricacies of nano-assembly (NA) techniques, focusing on oriented-assembly methodologies and stimuli-dependent approaches. The introduction provides a comprehensive overview of the significance and potential applications of NA, setting the stage for review. The oriented-assembly section elucidates methodologies for the precise alignment and organization of NMs, crucial for achieving desired functionalities. The subsequent section delves into stimuli-dependent techniques, categorizing them into chemical and physical stimuli-based approaches. Chemical stimuli-based self-assembly methods, including solvent, acid-base, biomolecule, metal ion, and gas-induced assembly, are discussed in detail by presenting examples. Additionally, physical stimuli such as light, magnetic fields, electric fields, and temperature are examined for their role in driving self-assembly processes. Looking ahead, the review outlines futuristic scopes and perspectives in NA, highlighting emerging trends and potential breakthroughs. Finally, concluding remarks summarize key findings and underscore the significance of NA in shaping future technologies. This comprehensive review serves as a valuable resource for researchers and practitioners, offering insights into the diverse methodologies and potential applications of NA in interdisciplinary research fields.

An Encyclopedic Compendium on Chemosensing Supramolecular Metal-Organic Gels

Chemosensing, an interdisciplinary scientific domain, plays a pivotal role ranging from environmental monitoring to healthcare diagnostics and (inter)national security. Metal-organic gels (MOGs) are recognized for their stability, selectivity, and responsiveness, making them valuable for chemosensing applications. Researchers have explored the development of MOGs based on different metal ions and ligands, allowing for tailored properties and sensitivities, and have even demonstrated their applications as portable sensors such as paper-based test strips for practical use. Herein, several studies related to MOGs development and their applications in the chemosensing field via UV-visible or luminance along with electrochemical approach are presented. These papers explored MOGs as versatile materials with their use in sensing bio or environmental analytes. This review provides a foundational understanding of key concepts, methodologies, and recent advancements in this field, fostering the scientific community.

Amino acid-based metallo-supramolecular nanoassemblies capable of regulating cellular redox homeostasis for tumoricidal chemo-/photo-/catalytic combination therapy

Nanozymes, as nanomaterials with natural enzyme activities, have been widely applied to deliver various therapeutic agents to synergistically combat the progression of malignant tumors. However, currently common inorganic nanozyme-based drug delivery systems still face challenges such as suboptimal biosafety, inadequate stability, and inferior tumor selectivity. Herein, a super-stable amino acid-based metallo-supramolecular nanoassembly (FPIC NPs) with peroxidase (POD)- and glutathione oxidase (GSHOx)-like activities was fabricated via Pt4+-driven coordination co-assembly of l-cysteine derivatives, the chemotherapeutic drug curcumin (Cur), and the photosensitizer indocyanine green (ICG). The superior POD- and GSHOx-like activities could not only catalyze the decomposition of endogenous hydrogen peroxide into massive hydroxyl radicals, but also deplete the overproduced glutathione (GSH) in cancer cells to weaken intracellular antioxidant defenses. Meanwhile, FPIC NPs would undergo degradation in response to GSH to specifically release Cur, causing efficient mitochondrial damage. In addition, FPIC NPs intrinsically enable fluorescence/photoacoustic imaging to visualize tumor accumulation of encapsulated ICG in real time, thereby determining an appropriate treatment time point for tumoricidal photothermal (PTT)/photodynamic therapy (PDT). In vitro and in vivo findings demonstrated the quadruple orchestration of catalytic therapy, chemotherapeutics, PTT, and PDT offers conspicuous antineoplastic effects with minimal side reactions. This work may provide novel ideas for designing supramolecular nanoassemblies with multiple enzymatic activities and therapeutic functions, allowing for wider applications of nanozymes and nanoassemblies in biomedicine.

Metal-Drug Coordination Nanoparticles and Hydrogels for Enhanced Delivery

Drug delivery is a key component of nanomedicine, and conventional delivery relies on the adsorption or encapsulation of drug molecules to a nanomaterial. Many delivery vehicles contain metal ions, such as metal-organic frameworks, metal oxides, transition metal dichalcogenides, MXene, and noble metal nanoparticles. These materials have a high metal content and pose potential long-term toxicity concerns leading to difficulties for clinical approval. In this review, recent developments are summarized in the use of drug molecules as ligands for metal coordination forming various nanomaterials and soft materials. In these cases, the drug-to-metal ratio is much higher than conventional adsorption-based strategies. The drug molecules are divided into small-molecule drugs, nucleic acids, and proteins. The formed hybrid materials mainly include nanoparticles and hydrogels, upon which targeting ligands can be grafted to improve efficacy and further decrease toxicity. The application of these materials for addressing cancer, viral infection, bacterial infection inflammatory bowel disease, and bone diseases is reviewed. In the end, some future directions are discussed from fundamental research, materials science, and medicine.

A Nanoscale Trans-Platinum(II)-Based Supramolecular Coordination Self-Assembly with a Distinct Anticancer Mechanism

Drug resistance significantly hampers the clinical application of existing platinum-based anticancer drugs. New platinum medications that possess distinct mechanisms of action are highly desired for the treatment of Pt-resistant cancers. Herein, a nanoscale trans-platinum(II)-based supramolecular coordination self-assembly (Pt-TCPP-BA) is prepared via using trans-[PtCl2(pyridine)(NH3)] (transpyroplatin), tetracarboxylporphyrin (TCPP), and benzoic acid (BA) as building blocks to combat drug resistance in platinum-based chemotherapy. Mechanistic studies indicate that Pt-TCPP-BA shows a hydrogen-peroxide-responsive dissociation behavior along with the generation of bioactive trans-Pt(II) and TCPP-Pt species. Different from cisplatin, these degradation products interact with DNA via interstrand cross-links and small groove binding, and induce significant upregulation of cell-death-related proteins such as p53, cleaved caspase 3, p21, and phosphorylated H2A histone family member X in cisplatin-resistant cancer cells. As a result, Pt-TCPP-BA exhibits potent killing effects against Pt-resistant tumors both in vitro and in vivo. Overall, this work not only provides a new platinum drug for combating drug-resistant cancer but also offers a new paradigm for the development of platinum-based supramolecular anticancer drugs.

Therapeutic Peptides, Proteins and their Nanostructures for Drug Delivery and Precision Medicine

Peptide and protein nanostructures with tunable structural features, multifunctionality, biocompatibility and biomolecular recognition capacity enable development of efficient targeted drug delivery tools for precision medicine applications. In this review article, we present various techniques employed for the synthesis and self-assembly of peptides and proteins into nanostructures. We discuss design strategies utilized to enhance their stability, drug-loading capacity, and controlled release properties, in addition to the mechanisms by which peptide nanostructures interact with target cells, including receptor-mediated endocytosis and cell-penetrating capabilities. We also explore the potential of peptide and protein nanostructures for precision medicine, focusing on applications in personalized therapies and disease-specific targeting for diagnostics and therapeutics in diseases such as cancer.

Supramolecular Coordination Complexes for Synergistic Cancer Therapy

Supramolecular coordination complexes (SCCs) are predictable and size-tunable supramolecular self-assemblies constructed through directional coordination bonds between readily available organic ligands and metallic receptors. Based on planar and 3D structures, SCCs can be mainly divided into two categories: metallacycles (e.g., rhomboidal, triangular, rectangular, and hexagonal) and metallacages (e.g., tetrahedral, hexahedral, and dodecahedral). The directional coordination bonds enable the efficient formation of metallacycles and metallacages with well-defined architectures and geometries. SCCs exhibit several advantages, including good directionality, strong interaction force, tunable modularity, and good solution processability, making them highly attractive for biomedical applications, especially in cellular imaging and cancer therapy. Compared with their molecular precursors, SCCs demonstrate enhanced cellular uptake and a strengthened tumor accumulation effect, owing to their inherently charged structures. These properties and the chemotherapeutic potential inherent to organic platinum complexes have promoted their widespread application in antitumor therapy. Furthermore, the defined structures of SCCs, achieved via the design modification of assembly elements and introduction of different functional groups, enable them to combat malignant tumors through multipronged treatment modalities. Because the development of cancer-treatment methodologies integrated in clinics has evolved from single-modality chemotherapy to synergistic multimodal therapy, the development of functional SCCs for synergistic cancer therapy is crucial. While some pioneering reviews have explored the bioapplications of SCCs, often categorized by a specific function or focusing on the specific metal or ligand types, a comprehensive exploration of their synergistic multifunctionality is a critical gap in the current literature.In this Account, we focus on platinum-based SCCs and their applications in cancer therapy. While other metals, such as Pd-, Rh-, Ru-, and Ir-based SCCs, have been explored for cancer therapy by Therrien and Casini et al., platinum-based SCCs have garnered significant interest, owing to their unique advantages in antitumor therapy. These platinum-based SCCs, which enhance antitumor efficacy, are considered prominent candidates for cancer therapies owing to their desirable properties, such as potent antitumor activity, exceptionally low systemic toxicity, active tumor-targeting ability, and enhanced cellular uptake. Furthermore, diverse diagnostic and therapeutic modalities (e.g., chemotherapy, photothermal therapy, and photodynamic therapy) can be integrated into a single platform based on platinum-based SCCs for cancer therapy. Consequently, herein, we summarize our recent research on platinum-based SCCs for synergistic cancer therapy with particular emphasis on the cooperative interplay between different therapeutic methods. In the Conclusions section, we present the key advancements achieved on the basis of our research findings and propose future directions that may significantly impact the field.

NIR-Light-Triggered Mild-Temperature Hyperthermia to Overcome the Cascade Cisplatin Resistance for Improved Resistant Tumor Therapy

Currently, cisplatin resistance has been recognized as a multistep cascade process for its clinical chemotherapy failure. Hitherto, it remains challenging to develop a feasible and promising strategy to overcome the cascade drug resistance (CDR) issue for achieving fundamentally improved chemotherapeutic efficacy. Herein, a novel self-assembled nanoagent is proposed, which is constructed by Pt(IV) prodrug, cyanine dye (cypate), and gadolinium ion (Gd3+), for systematically conquering the cisplatin resistance by employing near-infrared (NIR) light activated mild-temperature hyperthermia in tumor targets. The proposed nanoagents exhibit high photostability, GSH/H+-responsive dissociation, preferable photothermal conversion, and enhanced cellular uptake performance. In particular, upon 785-nm NIR light irradiation, the generated mild temperature of ≈ 43 °C overtly improves the cell membrane permeability and drug uptake, accelerates the disruption of intracellular redox balance, and apparently enhances the formation of Pt-DNA adducts, thereby effectively overcoming the CDR issue and achieves highly improved therapeutic efficacy for cisplatin-resistant tumor ablation.

Brazilin-Ce nanoparticles attenuate inflammation by de/anti-phosphorylation of IKKβ

Inflammation is associated with a series of diseases like cancer, cardiovascular disease and infection, and phosphorylation/dephosphorylation modification of proteins are important in inflammation regulation. Here we designed and synthesized a novel Brazilin-Ce nanoparticle (BX-Ce NPs) using Brazilin, which has been used for anti-inflammation in cardiovascular diseases but with narrow therapeutic window, and Cerium (IV), a lanthanide which has the general activity in catalyzing the hydrolysis of phosphoester bonds, to conferring de/anti-phosphorylation of IKKβ. We found that BX-Ce NPs specifically bound to Asn225 and Lys428 of IKKβ and inhibited its phosphorylation at Ser181, contributing to appreciably anti-inflammatory effect in cellulo (IC50 = 2.5 μM). In vivo mouse models of myocardial infarction and sepsis also showed that the BX-Ce NPs significantly ameliorated myocardial injury and improved survival in mice with experimental sepsis through downregulating phosphorylation of IKKβ. These findings provided insights for developing metal nanoparticles for guided ion interfere therapy, particularly synergistically target de/anti-phosphorylation as promising therapeutic agents for inflammation and related diseases.

Copper-coordinated nanoassemblies based on photosensitizer-chemo prodrugs and checkpoint inhibitors for enhanced apoptosis-cuproptosis and immunotherapy

Cuproptosis is a recently identified copper-dependent form of nonapoptotic cell death and holds great prospect in cancer treatment. One of the most intriguing aspects of cuproptosis is its ability to synergize with apoptosis-based cancer treatments. Herein, we presented a novel approach using copper-coordinated nanoassemblies (CCNAs) that were constructed by incorporating a photosensitizer Zinc Phthalocyanine (ZnPc)-chemotherapeutic (DOX) prodrug with a thioketal (TK) spacer and an IDO inhibitor (1-methyl tryptophan, 1-MT) as building blocks for Cu2+-coordination self-assembly to achieve combinational apoptosis-cuproptosis and immunotherapy. Upon NIR laser irradiation, the ZnPc component of CCNAs exhibited a photodynamic effect that generated reactive oxygen species (ROS). This triggered the release of DOX, leading to enhanced tumor cell apoptosis. Additionally, the presence of Cu2+ in the CCNAs not only enhanced the photodynamic process by catalyzing oxygen generation but also promoted the aggregation of toxic mitochondrial proteins, leading to cell cuproptosis. Importantly, the intensified cuproptosis-apoptosis effect triggered an immunogenic cell death (ICD) response. The released 1-MT complemented this response by reversing the immunosuppressive tumor microenvironment (ITM), synergistically amplifying anti-tumor immunity and suppressing the growth of primary and distant tumors. The findings of this study provide a new perspective on potential cancer treatments based on cuproptosis-apoptosis synergistic immunotherapy and stimulate further research in the design of advanced metal-coordinated nanomedicines. STATEMENT OF SIGNIFICANCE: The combination of cuproptosis and apoptosis that act with different mechanisms holds enormous potential in cancer treatment. Here, copper-coordinated nanoassemblies (CCNAs) based on photosensitizer-chemo prodrugs and checkpoint inhibitors were constructed for mediating cuproptosis-apoptosis and subsequently promoting cancer immunotherapy. CCNAs not only promoted the photodynamic effect and activation of chemotherapy through catalyzing the generation of oxygen but also induced toxic mitochondrial protein aggregation, leading to cell cuproptosis. These synergistic antitumor effects triggered robust immune responses with the aid of immune checkpoint blockade, almost eradicating primary tumors and inhibiting distant tumors by around 83 % without systemic toxicity.

Synthesis of 177Lu-Labeled, Somatostatin-2 Receptor-Targeted Metalla-Assemblies: Challenges in the Design of Supramolecular Radiotherapeutics

Self-assembled supramolecular coordination complexes (SCCs) hold promise for biomedical applications in cancer therapy, although their potential in the field of nuclear medicine is still substantially unexplored. Therefore, in this study an exo-functionalized cationic [Pd2L2]4+ metallacycle (L = 3,5-bis(3-ethynylpyridine)phenyl), targeted to the somatostatin-2 receptor (sst2R) and featuring the DOTA chelator (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) in order to bind the β-- and γ-emitter lutetium-177, was synthesized by self-assembly following ligand synthesis via standard solid-phase peptide synthesis (SPPS). This metallacycle was then characterized by reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry (ESI-MS), and 1H and 1H-DOSY NMR (DOSY = diffusion-ordered spectroscopy). A procedure for the radiolabeling of the metallacycle with 177Lu was also optimized. The resulting [nat/177Lu]Lu-DOTA-metallacycle, termed [nat/177Lu]Lu-Cy, was evaluated concerning its stability and in vitro properties. The compound was more lipophilic compared to the reference [177Lu]Lu-DOTA-TATE (logPOct/H2O = -0.85 ± 0.10 versus -3.67 ± 0.04, respectively). While [natLu]Lu-Cy revealed low stability in a DMEM/F12 GlutaMax medium, it demonstrated good stability in other aqueous media as well as in DMSO. A high sst2R binding affinity (expressed as IC50) was determined in CHOsst2 cells (Chinese hamster ovary cells that were stably transfected with human sst2R). Moreover, the metallacycle exhibited high human serum albumin binding, as assessed by high-performance affinity chromatography (HPAC), and moderate stability in human serum compared to [177Lu]Lu-DOTA-TATE (TATE = (Tyr3)-octreotate). In order to improve stability, a heteroleptic approach was used to develop a less sterically hindered cage-like SCC that is potentially endowed with host-guest chemistry capability, which has been preliminarily characterized by RP-HPLC and ESI-MS. Overall, our initial results encourage future studies on sst2R-directed SCCs and have led to new insights into the chemistry of ss2R-directed SCCs for radiopharmaceutical applications.

Multifunctional nano MOF drug delivery platform in combination therapy

Recent preclinical and clinical studies have demonstrated that for cancer treatment, combination therapies are more effective than monotherapies in reducing drug-related toxicity, decreasing drug resistance, and improving therapeutic efficacy. With the rapid development of nanotechnology, the combination of metal-organic frameworks (MOFs) and multi-mode therapy offers a realistic possibility to further improve the shortcomings of cancer treatment. This article focuses on the latest developments, achievements, and treatment strategies of representative multifunctional MOF combination therapies for cancer treatment in recent years, which include not only bimodal combination therapies, but also multi-modal synergistic therapies, further demonstrating the effectiveness and superiority of the MOF drug delivery systems in cancer treatment.

Metal ions as effectual tools for cancer with traditional Chinese medicine

Malignant tumor has become a major threat affecting human health, and is one of the main causes of human death. Recent studies have shown that many traditional Chinese medicines (TCM) have good anti-tumor activity, which may improve the therapeutic effect of routine treatment and quality of life with lower toxicity. However, the efficacy of TCM alone for the treatment of tumors is limited. Metal ions are essential substances for maintaining normal physiological activities. This article summarized the multiple mechanisms in which metal ions are involved in the prevention and treatment of tumors in TCM.

Insights into diphenylalanine peptide self-assembled nanostructures for integration as nanoplatforms in analytical and medical devices

New insights on the self-assembling process of diphenylalanine (FF) into nanostructures in view of its application as an alternative nanomaterial for bioanalytical and biomedical systems are presented in the frame of the present work. Experimental conditions, such as peptide concentration and solubilization medium pH, were explored to understand the hierarchical process involved in the formation of self-assembled nanostructures arising from the simple and short diphenylalanine peptide. Optical microscopic and TEM images supported by DLS data authenticated the hierarchical self-assembly outcoming from the original nature of the first nanostructures, showing individual nanotubes and vesicles stacking to grow well-defined microtubes. Moreover, the influence of metal cations on peptide self-assembly was evaluated for the first time in the presence of Mg2+ and compared with other ions, such as Na+, K+, and Ca2+. The results evidenced a tendency of Mg2+ to interact with diphenylalanine peptides to form self-assembled nanostructures showing vesicle- and ellipse-like morphologies. FF solubilization in water prepared under sonication in a bath at 65-68°C followed by dilution into chloride metal cation solutions at 50 mmol.L-1 proved to be optimal conditions to obtain metal-coordinated self-assembled FF structures. Besides, the latter revealed fluorescence features and electron-transfer properties on carbon-based electrode surfaces, that can be further explored in analytical and bioanalytical devices for fully integrated platforms. In this context, self-assembled nanostructures achieved in the presence of Mg2+ and Ca2+ were implemented for the surface modification of carbon screen-printed electrodes and proved to increase the electrochemical response toward a redox probe. This proof of concept is particularly interesting for further use of these peptide-based nanoarchitectures as nanoplatforms for clinical imaging, therapeutic and diagnosis purposes.

Self-delivery of a metal-coordinated anti-angiogenic nanodrug with GSH depleting ability for synergistic chemo-phototherapy

Synergistic chemo-phototherapy has offered tremendous potential in cancer treatment. Nevertheless, nanosystems usually suffer from the complexity of multicomponents (polymeric or inorganic materials), which results in carrier-related toxicity issues. Moreover, the GSH over-expression of tumor cells seriously compromises ROS therapeutic efficiency. Herein, we designed a self-delivered nanodrug via Cu(II) coordination-driven co-self-assembly of celastrol (CST, a chemo-drug with anti-angiogenesis activity) and indocyanine green (ICG, a photosensitizer) for synergistic chemo-phototherapy with GSH depletion. The nanodrug was further cloaked by an erythrocyte membrane (RBC) to prolong the circulation time. Within the tumor microenvironment, the nanodrug would be disassembled upon intracellular GSH triggering. Moreover, the released Cu(II) could efficiently deplete the GSH, thus damaging the ROS-scavenging system and amplifying the phototherapeutic efficiency upon laser irradiation. The in vivo experiments validated the highly effective accumulation at tumor sites, potent tumor growth inhibition, and inappreciable systemic toxicity. The tumor microenvironment-responsive coordination-driven self-assembled biomimetic nanodrug may hold potential applications in tumor theranostics.

Advance Progress in Assembly Mechanisms of Carrier-Free Nanodrugs for Cancer Treatment

Nanocarriers have been widely studied and applied in the field of cancer treatment. However, conventional nanocarriers still suffer from complicated preparation processes, low drug loading, and potential toxicity of carriers themselves. To tackle the hindrance, carrier-free nanodrugs with biological activity have received increasing attention in cancer therapy. Extensive efforts have been made to exploit new self-assembly methods and mechanisms to expand the scope of carrier-free nanodrugs with enhanced therapeutic performance. In this review, we summarize the advanced progress and applications of carrier-free nanodrugs based on different types of assembly mechanisms and strategies, which involved noncovalent interactions, a combination of covalent bonds and noncovalent interactions, and metal ions-coordinated self-assembly. These carrier-free nanodrugs are introduced in detail according to their assembly and antitumor applications. Finally, the prospects and existing challenges of carrier-free nanodrugs in future development and clinical application are discussed. We hope that this comprehensive review will provide new insights into the rational design of more effective carrier-free nanodrug systems and advancing clinical cancer and other diseases (e.g., bacterial infections) infection treatment.

Multifunctional Crystalline Coordination Polymers Constructed from 4,4'-Bipyridine-N,N'-dioxide: Photochromism, White-Light Emission, and Photomagnetism

Multifunctional photochromic coordination polymers (CPs) have shown great potential in many areas, like molecular switches, anticounterfeiting, magnetics, and optoelectronics. Although multifunctional photochromic CPs can be obtained by introducing photoresponsive functional units or by exploiting the synergy effect of each component, relatively limited photochromic ligands hinder the development of various multifunctional photochromic CPs. In this work, we reported two multifunctional coordination polymers {[Zn(bpdo)(fum)(H2O)2]}n (1) and {[Mn(bpdo)(fum)(H2O)2]}n (2) based on an easily accessible but underestimated photoactive molecule 4,4'-bipyridine-N,N'-dioxide (bpdo). Compound 1 exhibits photochromism and white-light emission with an ultra-high color rendering index (CRI) of 92.1. Interestingly, compound 1 could emit intrinsic white light in the crystalline state upon UV irradiation both before and after photochromism. Meanwhile, compound 2 displays photochromic and photomagnetic properties, induced by the photogenerated radicals via a photoinduced electron transfer mechanism.

pH-Activatable copper-axitinib coordinated multifunctional nanoparticles for synergistic chemo-chemodynamic therapy against aggressive cancers

Chemodynamic therapy (CDT) is an emerging oncological treatment that eliminates tumor cells by generating lethal hydroxyl radicals (˙OH) through Fenton or Fenton-like reactions within tumors. However, the effectiveness of CDT is limited by the overexpression of glutathione (GSH) and low reaction efficiency in the tumor microenvironment (TME). To address these challenges and enhance tumor treatment, we developed a novel pH-activatable metal ion-drug coordinated nanoparticle (Cu-AXB NPs) system, incorporating a CDT agent (Cu2+) and a chemotherapeutic agent (axitinib, AXB). The obtained Cu-AXB NPs exhibited exceptional characteristics, including ultrahigh drug loading capacity (87.55%) and an average size of 180 nm. These nanoparticles also demonstrated excellent plasma stability and pH-responsive drug release, enabling prolonged circulation in the bloodstream and targeted therapy at weakly acidic tumor sites. Upon release, AXB acted as a chemotherapeutic agent, effectively eliminating tumor cells, while Cu2+ ions were reduced to Cu+ by GSH, further generating toxic ˙OH with hydrogen peroxide (H2O2) for CDT through a Fenton-like reaction. Additionally, the Cu-AXB NPs efficiently disrupted the copper metabolic balance and increased the intracellular Cu content, further amplifying the therapeutic impact of CDT. In vitro studies assessing cytotoxicity and apoptosis confirmed the superior tumor cell-killing efficacy of the Cu-AXB NPs. This enhanced efficacy can be attributed to the synergistic effect of CDT and chemotherapy. Moreover, the Cu-AXB NPs exhibited excellent tumor targeting capabilities, resulting in significant tumor inhibition (77.53% inhibition) while maintaining favorable biocompatibility in tumor-bearing mice. In conclusion, this study presents a promising and safe strategy for cancer therapy by combining CDT with chemotherapy, offering a potential breakthrough in the field of oncology.

Recent Advances of Metal-Polyphenol Coordination Polymers for Biomedical Applications

Nanomedicine has provided cutting-edge technologies and innovative methods for modern biomedical research, offering unprecedented opportunities to tackle crucial biomedical issues. Nanomaterials with unique structures and properties can integrate multiple functions to achieve more precise diagnosis and treatment, making up for the shortcomings of traditional treatment methods. Among them, metal-polyphenol coordination polymers (MPCPs), composed of metal ions and phenolic ligands, are considered as ideal nanoplatforms for disease diagnosis and treatment. Recently, MPCPs have been extensively investigated in the field of biomedicine due to their facile synthesis, adjustable structures, and excellent biocompatibility, as well as pH-responsiveness. In this review, the classification of various MPCPs and their fabrication strategies are firstly summarized. Then, their significant achievements in the biomedical field such as biosensing, drug delivery, bioimaging, tumor therapy, and antibacterial applications are highlighted. Finally, the main limitations and outlooks regarding MPCPs are discussed.

Enzyme-Activatable Polypeptide for Plasma Membrane Disruption and Antitumor Immunity Elicitation

Enzyme-instructed self-assembly of bioactive molecules into nanobundles inside cells is conceived to potentially disrupt plasma membrane and subcellular structure. Herein, an alkaline phosphatase (ALP)-activatable hybrid of ICG-CF₄ KY^p is facilely synthesized by conjugating photosensitizer indocyanine green (ICG) with CF₄ KY^p peptide via classical Michael addition reaction. ALP-induced dephosphorylation of ICG-CF₄ KY^p enables its transformation from small-molecule precursor into rigid nanofibrils, and such fibrillation in situ causes severe mechanical disruption of cytomembrane. Besides, ICG-mediated photosensitization causes additional oxidative damage of plasma membrane by lipid peroxidation. Hollow MnO₂ nanospheres devote to deliver ICG-CF₄ KY^p into tumorous tissue through tumor-specific acidity/glutathione-triggered degradation of MnO₂ , which is monitored by fluorescent probing and magnetic resonance imaging. The burst release of damage-associated molecular patterns and other tumor antigens during therapy effectively triggers immunogenetic cell death and improves immune stimulatory, as demonstrated by the promotion of dendritic cell maturation and CD8⁺ lymphocyte infiltration, as well as constraint of regulatory T cell population. Taken together, such cytomembrane injury strategy based on peptide fibrillation in situ holds high clinical promise for lesion-specific elimination of primary, abscopal, and metastatic tumors, which may enlighten more bioinspired nanoplatforms for anticancer theranostics.

In Situ Transformable Nanoplatforms with Supramolecular Cross-Linking Triggered Complementary Function for Enhanced Cancer Photodynamic Therapy

In vivo cross-linking of nanoparticles is widely used to increase accumulation of therapeutic agents at tumor site for enhanced therapy. However, the components in nanoplatforms usually only play for one role and are independent of each other, unable to amplify their biofunctions. Herein, a complementary functioning tumor microenvironment triggered, supramolecular coordination-induced nanoparticle cross-linking strategy is constructed for enhanced photodynamic therapy. Manganese oxide (MnO_x ) and polyhydroxy photosensitizer hypericin (Hyp) are coated and loaded onto lanthanide-doped upconversion nanoparticles (UCNPs) to form transformable UCNP@MnO_x -Hyp. In CT26 mouse colon cancer cells and xenograft tumors, UCNP@MnO_x -Hyp is reduced by glutathione and H₂ O₂ , releasing Mn²⁺ and Hyp for in situ cross-linking to transform to UCNP@Mn²⁺ -Hyp. Compared to the simple photosensitizer-loaded UCNP@PEI-Hyp, the Mn²⁺ -Hyp coordination redshifts absorbance of Hyp and improves the energy transfer efficiency from UCNPs to Hyp (5.6-fold). In turn, the supramolecular coordination-induced UCNPs cross-linking exhibits enhanced luminescence recovery and increased intracellular accumulation of both UCNPs and Hyp, thus enhancing the photodynamic therapy efficacy both at cellular level (2.1-fold) and in vivo, realizing the function amplification of each component after responsive transformation and offering a new avenue for enhanced cancer therapy.

NIR-IIb fluorescence-image guided synergistic surgery/starvation/chemodynamic therapy: an innovative treatment paradigm for malignant non-small cell lung cancers

Background: Currently, the prognosis and survival rate for patients bearing non-small cell lung cancer (NSCLC) is still quite poor, mainly due to lack of efficient theranostic paradigms to exert in time diagnostics and therapeutics. Methods: Herein, for NSCLC treatment, we offer a customized theranostic paradigm, termed NIR-IIb fluorescence diagnosis and synergistic surgery/starvation/chemodynamic therapeutics, with a newly designed theranostic nanoplatform PEG/MnCuDCNPs@GOx. The nanoplatform is composed of brightly NIR-II emissive downconversion nanoparticles (DCNPs)-core and Mn/Cu-silica shell loaded with glucose oxidase (GOx) to achieve synergistic starvation and chemodynamic therapy (CDT). Results: It is found that 10% Ce3+ doped in the core and 100% Yb3+ doped in the middle shell greatly improves the NIR-IIb emission up to even 20.3 times as compared to the core-shell DCNPs without Ce3+ doping and middle shell. The bright NIR-IIb emission of the nanoplatform contributes to sensitive margin delineation of early-stage NSCLC (diameter < 1 mm) with a signal-to-background ratio (SBR) of 2.18, and further assists in visualizing drug distribution and guiding surgery/starvation/chemodynamic therapy. Notably, the starvation therapy mediated by GOx-driven oxidation reaction efficiently depletes intratumoral glucose, and supplies H2O2 to boost the CDT mediated by the Mn2+ and Cu2+, which consequently realized a highly effective synergistic treatment for NSCLC. Conclusion: This research demonstrates an efficient treatment paradigm for NSCLC with NIR-IIb fluorescence diganosis and image-guided synergistic surgery/starvation/chemodynamic therapeutics.

Continuous Spatiotemporal Therapy of A Full-API Nanodrug via Multi-Step Tandem Endogenous Biosynthesis

Nanomedicine holds great promise to enhance cancer therapy. However, low active pharmaceutical ingredient (API) loading content, unpredictable drug release, and potential toxicity from excipients limit their translational capability. We herein report a full-API nanodrug composed of FDA-approved 5-aminolevulinic acid (ALA), human essential element Fe3+, and natural bioactive compound curcumin with an ideal API content and pH-responsive release profile for continuous spatiotemporal cancer therapy achieved by multi-step tandem endogenous biosynthesis. First, ALA enzymatically converts into photosensitizer protoporphyrin IX (PpIX). Afterward, multiple downstream products including carbon monoxide (CO), Fe2+, biliverdin (BV), and bilirubin (BR) are individually biosynthesized through the PpIX-heme-CO/Fe2+/BV-BR metabolic pathway, further cooperating with released Fe3+ and curcumin, ultimately eliciting mitochondria damage, membrane disruption, and intracytoplasmic injury. This work not only provides a paradigm for exploiting diversified metabolites for tumor suppression, but also presents a safe and efficient full-API nanodrug, facilitating the practical translation of nanodrugs.

Cupric-ion-promoted fabrication of oxygen-replenishing nanotherapeutics for synergistic chemo and photodynamic therapy against tumor hypoxia

Mixing a glutathione (GSH)-responsive carboxy zinc(II) phthalocyanine (ZnPc*) and CuSO₄·5H₂O in water with or without the presence of the anticancer drug SN38 resulted in the formation of self-assembled nanotherapeutics labeled as ZnPc*/Cu/SN38@NP and ZnPc*/Cu@NP, respectively. The Cu²⁺ ions not only promoted the self-assembly of the carboxy phthalocyanine through metal complexation, but also catalyzed the transformation of H₂O₂ to oxygen via a catalase-like reaction, rendering an oxygen-replenishing property to the nanosystems. Both nanosystems exhibited high stability in aqueous media, but the nanoparticles disassembled gradually in an acidic or GSH-enriched environment and inside human colorectal adenocarcinoma HT29 cells, releasing the encapsulated therapeutic components. The disassembly process together with the activation by the intracellular GSH led to relaxation of the intrinsic quenching of the nanophotosensitizers and restoration of the photoactivities of ZnPc*. Under a hypoxic condition, ZnPc*/Cu/SN38@NP could attenuate the intracellular hypoxia level and maintain the photodynamic activity due to its Cu²⁺-promoted oxygen-replenishing ability. The photodynamic effect of ZnPc* and the anticancer effect of SN38 worked cooperatively, causing substantial apoptotic cell death. The dual therapeutic actions could also effectively inhibit the tumor growth in HT29 tumor-bearing nude mice without initiating notable adverse effects to the mice. STATEMENT OF SIGNIFICANCE: The oxygen-dependent nature of photodynamic therapy generally reduces its efficacy against tumor hypoxia, which is a common characteristic of advanced solid tumors and usually leads to resistance toward various anticancer therapies. We report herein a facile approach to assemble a glutathione-responsive carboxy phthalocyanine-based photosensitizer and an anticancer drug in aqueous media, in which Cu(II) ions were used to promote the self-assembly through metal complexation and catalyze the conversion of H₂O₂ to oxygen through a catalase-like reaction, making the resulting nanoparticles possessing an oxygen-replenishing property that could promote the photodynamic effect against hypoxic cancer cells and tumors. The use of Cu(II) ions to achieve the aforementioned dual functions in the fabrication of advanced nano-photosensitizing systems has not been reported.

Hot-band absorption assisted single-photon frequency upconversion luminescent nanophotosensitizer for 808 nm light triggered photodynamic immunotherapy of cancer

Frequency upconversion luminescence (FUCL) based on hot-band absorption has attracted considerable attention in bioimaging and phototherapy fields for deep-seated cancer treatment. Photoimmunotherapy, a promising therapeutic approach induced by photodynamic therapy (PDT), can selectively kill cancer cells, reverse the immunosuppressive system, boost host immune response, and elicit durable antitumor immunity. To date, few near-infrared organic photosensitizers for photodynamic immunotherapy have been reported based on hot-band absorption. Herein, we report an upconversion luminescent phthalocyanine photosensitizer PdPc(OBu)₈ with anti-Stokes emission at 748 nm and highly efficient singlet oxygen generation with hot-band absorption at 808 nm. Taking advantage of nanoliposomes, FUCL phthalocyanine nano-photosensitizers (PdPc NPs) were obtained to reduce the aggregation-caused quenching and improve water solubility and biocompatibility. PdPc NPs could be effectively accumulated in tumor tissues through intravenous administration, causing FUCL-induced PDT under 808 nm irradiation. Considering its finite immune responses and tumor ablation after PDT, a combination of PdPc NP-based PDT with checkpoint inhibitors (anti-PD-L1) for near-infrared photoimmunotherapy has been used to potentiate the antitumor efficacy that could simultaneously ablate primary tumors and inhibit the progression of distant tumors. This study can promote the development of upconversion-based PDT combined with immunotherapy for tumor precision therapy.

A Non-Hydrolysis Reaction-Based Imine for Fluorescence Response toward Al3+ Ions with Extremely High Selectivity

Designing an imine-based fluorescent probe capable of greatly suppressing the tendency of intrinsic hydrolysis reaction is an attractive topic in the field of chemo-/biosensing. In this work, hydrophobic 1,1'-binaphthyl-2,2'-diamine containing two amine groups was introduced to synthesize probe R-1 bearing two imine bonds linked by two salicylaldehyde (SAs). The hydrophobicity of binaphthyl moiety and the unique clamp-like structure formed from double imine bonds and from ortho-OH on SA part make probe R-1 is able to function as an ideal receptor to coordinate with Al³⁺ ions, leading to the fluorescence originated from the complex rather than from the assumed hydrolyzed fluorescent amine is turned on. Further study revealed that, when Al³⁺ ions were introduced, both the hydrophobic binaphthyl moiety and the clamp-like double imine structure in the designed imine-based probe showed important contributions to suppress the intrinsic hydrolysis reaction, resulting in generating a stable coordination complex with an extremely high selectivity in fluorescence response.

Iron(II) Mediated Supramolecular Architectures with Schiff Bases and Their Spin-Crossover Properties

Supramolecular architectures, which are formed through the combination of inorganic metal cations and organic ligands by self-assembly, are one of the techniques in modern chemical science. This kind of multi-nuclear system in various dimensionalities can be implemented in various applications such as sensing, storage/cargo, display and molecular switching. Iron(II) mediated spin-crossover (SCO) supramolecular architectures with Schiff bases have attracted the attention of many investigators due to their structural novelty as well as their potential application possibilities. In this paper, we review a number of supramolecular SCO architectures of iron(II) with Schiff base ligands exhibiting varying geometrical possibilities. The structural and SCO behavior of these complexes are also discussed in detail.

PET Imaging of Self-Assembled 18 F-Labelled Pd2 L4 Metallacages for Anticancer Drug Delivery

To advance the design of self-assembled metallosupramolecular architectures as new generation theranostic agents, the synthesis of ¹⁸ F-labelled [Pd₂ L₄ ]⁴⁺ metallacages is reported. Different spectroscopic and bio-analytical methods support the formation of the host-guest cage-cisplatin complex. The biodistribution profiles of one of the cages, alone or encapsulating cisplatin have been studied by PET/CT imaging in healthy mice in vivo, in combination to ICP-MS ex vivo.

Vacancy-Modulated of CuS for Highly Antibacterial Efficiency via Photothermal/Photodynamic Synergetic Therapy

Cu-based nanomaterials have been developed to alleviate the problem of antibiotic resistance due to their superior properties and good biocompatibility. Defects in nanomaterials have a major role in improving photocatalytic performance. Herein, two CuS nanospheres with predominant V_CuSCu and V_CuSS vacancy (abbreviated as CuS and CuS-T150, respectively) characterized by positron annihilation spectra are synthesized. The combination of experimental and theoretical calculation results demonstrates that CuS-T150 exhibits excellent antibacterial, achieving bactericidal rates of 99.9% against to Escherichia coli (E. coli) under 808 nm laser irradiation. Compared with CuS, the superior antimicrobial activity of CuS-T150 is mainly attributed to its stronger ability to adsorb oxygen molecules, more easily bind with surface of E. coli, and higher photothermal conversion efficiency (PTCE). This work provides a deeper understanding of nanomaterials with vacancy modulated the antibacterial efficiency by synergistic effect of photodynamic and photothermal therapy.

Bioinorganic supramolecular coordination complexes and their biomedical applications

The field of Bioinorganic Supramolecular Chemistry is an emerging research area including metal-based supramolecules resulting from coordination-driven self-assembly (CDSA), whereby metal ions and organic ligands can be easily linked by metal-ligand bonds via Lewis' acid/base interactions. The focus of this 'In a Nutshell' review will be on the family of supramolecular coordination complexes, discrete entities formed by CDSA, which have recently captured widespread attention as a new class of versatile multifunctional materials with broad biological applications including molecular recognition, biosensing, therapy, imaging and drug delivery. Herein, we provide a summary of the state-of-the-art use of these systems in biomedicine, with some selected representative examples, as well as our visions of the challenges and possible directions in the field.

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.