Platinum drugs: from Pt(II) compounds, Pt(IV) prodrugs, to Pt nanocrystals/nanoclusters

Disrupting glycolysis and DNA repair in anaplastic thyroid cancer with nucleus-targeting platinum nanoclusters

Cancer cells rely on aerobic glycolysis and DNA repair signals to drive tumor growth and develop drug resistance. Yet, fine-tuning aerobic glycolysis with the assist of nanotechnology, for example, dampening lactate dehydrogenase (LDH) for cancer cell metabolic reprograming remains to be investigated. Here we focus on anaplastic thyroid cancer (ATC) as an extremely malignant cancer with the high expression of LDH, and develop a pH-responsive and nucleus-targeting platinum nanocluster (Pt@TAT/sPEG) to simultaneously targets LDH and exacerbates DNA damage. Pt@TAT/sPEG effectively disrupts LDH activity, reducing lactate production and ATP levels, and meanwhile induces ROS production, DNA damage, and apoptosis in ATC tumor cells. We found Pt@TAT/sPEG also blocks nucleotide excision repair pathway and achieves effective tumor cell killing. In an orthotopic ATC xenograft model, Pt@TAT/sPEG demonstrates superior tumor growth suppression compared to Pt@sPEG and cisplatin. This nanostrategy offers a feasible approach to simultaneously inhibit glycolysis and DNA repair for metabolic reprogramming and enhanced tumor chemotherapy.

Metal nanoparticles for cancer therapy: Precision targeting of DNA damage

Cancer, a complex and heterogeneous disease, arises from genomic instability. Currently, DNA damage-based cancer treatments, including radiotherapy and chemotherapy, are employed in clinical practice. However, the efficacy and safety of these therapies are constrained by various factors, limiting their ability to meet current clinical demands. Metal nanoparticles present promising avenues for enhancing each critical aspect of DNA damage-based cancer therapy. Their customizable physicochemical properties enable the development of targeted and personalized treatment platforms. In this review, we delve into the design principles and optimization strategies of metal nanoparticles. We shed light on the limitations of DNA damage-based therapy while highlighting the diverse strategies made possible by metal nanoparticles. These encompass targeted drug delivery, inhibition of DNA repair mechanisms, induction of cell death, and the cascading immune response. Moreover, we explore the pivotal role of physicochemical factors such as nanoparticle size, stimuli-responsiveness, and surface modification in shaping metal nanoparticle platforms. Finally, we present insights into the challenges and future directions of metal nanoparticles in advancing DNA damage-based cancer therapy, paving the way for novel treatment paradigms.

Progress in the study of reproductive toxicity of platinum-based antitumor drugs and their means of prevention

Platinum-based antitumor drugs are broad-spectrum agents with unique mechanisms of action. Combination chemotherapy regimens based on platinum drugs are commonly used in cancer treatment. However, these drugs can cause various adverse reactions in the human body through different routes of administration, including reproductive toxicity, genetic toxicity, and embryonic developmental toxicity. Preventing adverse effects is crucial to enhance patients' quality of life and reduce healthcare costs. This article discusses the types and developmental history of antitumor active platinum compounds, their mechanisms of action, routes of administration, and their potential reproductive, genetic, and embryonic developmental toxicity. This text explores preventive measures based on animal experimental results. Its aim is to provide references for personalized treatment and occupational protection when using platinum drugs. The continuous progress of science and technology, along with the deepening of medical research, suggests that the application of platinum drugs will broaden. Therefore, the development of new platinum drugs will be an important direction for future research.

A Dual Stimuli-Responsive Nanoplatform Loaded PtIV -Triptolide Prodrug for Achieving Synergistic Therapy toward Breast Cancer

To strengthen the antitumor efficacy and avoid toxicity to normal cells of cisplatin and triptolide, herein, an acid and glutathione (GSH) dual-controlled nanoplatform for enhanced cancer treatment through the synergy of both "1+1" apoptosis and "1+1" ferroptosis is designed. Remarkably, ZIF8 in response to tumor microenvironment enhances drug targeting and protects drugs from premature degradation. Meanwhile, the PtIV  center can be easily reduced to cisplatin because of the large amount of GSH, thus liberating the triptolide as the coordinated ligand. The released cisplatin and hemin in turn boost the tumor cell "1+1" apoptosis through chemotherapy and photodynamic therapy, respectively. Furthermore, GSH reduction through PtIV  weakens the activation of glutathione peroxidase 4 (GPX4) effectively. The released triptolide can inhibit the expressions of GSH by regulating nuclear factor E2 related factor 2 (Nrf2), further promoting membrane lipid peroxidation, thus "1+1" ferroptosis can be achieved. Both in vitro and in vivo results demonstrate that the nanosystem can not only perform superior specificity and therapeutic outcomes but also reduce the toxicity to normal cells/tissues of cisplatin and triptolide effectively. Overall, the prodrug-based smart system provides an efficient therapeutic strategy for cancer treatment by virtue of the effect of enhanced "1+1" apoptosis and "1+1" ferroptosis therapies.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

Subcellular visualization: Organelle-specific targeted drug delivery and discovery

Organelles perform critical biological functions due to their distinct molecular composition and internal environment. Disorders in organelles or their interacting networks have been linked to the incidence of numerous diseases, and the research of pharmacological actions at the organelle level has sparked pharmacists' interest. Currently, cell imaging has evolved into a critical tool for drug delivery, drug discovery, and pharmacological research. The introduction of advanced imaging techniques in recent years has provided researchers with richer biological information for viewing and studying the ultrastructure of organelles, protein interactions, and gene transcription activities, leading to the design and delivery of precision-targeted drugs. Therefore, this reviews the research on organelles-targeted drugs based upon imaging technologies and development of fluorescent molecules for medicinal purposes. We also give a thorough analysis of a number of subcellular-level elements of drug development, including subcellular research instruments and methods, organelle biological event investigation, subcellular target and drug identification, and design of subcellular delivery systems. This review will make it possible to promote drug research from the individual/cellular level to the subcellular level, as well as give a new focus based on newly found organelle activities.

Construction of the Heterostructure of NiPt Truncated Octahedral Nanoparticle/MoS2 and Its Interfacial Structure Evolution

Interfacial atomic configuration plays a vital role in the structural stability and functionality of nanocomposites composed of metal nanoparticles (NPs) and two-dimensional semiconductors. In situ transmission electron microscope (TEM) provides a real-time technique to observe the interface structure at atomic resolution. Herein, we loaded bimetallic NiPt truncated octahedral NPs (TONPs) on MoS₂ nanosheets and constructed a NiPt TONPs/MoS₂ heterostructure. The interfacial structure evolution of NiPt TONPs on MoS₂ was in situ investigated using aberration-corrected TEM. It was observed that some NiPt TONPs exhibited lattice matching with MoS₂ and displayed remarkable stability under electron beam irradiation. Intriguingly, the rotation of an individual NiPt TONP can be triggered by the electron beam to match the MoS₂ lattice underneath. Furthermore, the coalescence kinetics of NiPt TONPs can be quantitatively described by the relationship between neck radius (r) and time (t), expressed as rⁿ = Kt. Our work offers a detailed analysis of the lattice alignment relationship of NiPt TONPs on MoS₂, which may enlighten the design and preparation of stable bimetallic metal NPs/MoS₂ heterostructures.

Predicting 195 Pt NMR Chemical Shifts in Water-Soluble Inorganic/Organometallic Complexes with a Fast and Simple Protocol Combining Semiempirical Modeling and Machine Learning

Water-soluble Pt complexes are the key components in medicinal chemistry and catalysis. The well-known cisplatin family of anticancer drugs and industrial hydrosylilation catalysts are two leading examples. On the molecular level, the activity mechanisms of such complexes mostly involve changes in the Pt coordination sphere. Using ¹⁹⁵ Pt NMR spectroscopy for operando monitoring would be a valuable tool for uncovering the activity mechanisms; however, reliable approaches for the rapid correlation of Pt complex structure with ¹⁹⁵ Pt chemical shifts are very challenging and not available for everyday research practice. While NMR shielding is a response property, molecular 3D structure determines NMR spectra, as widely known, which allows us to build up 3D structure to ¹⁹⁵ Pt chemical shift correlations. Accordingly, we present a new workflow for the determination of lowest-energy configurational/conformational isomers based on the GFN2-xTB semiempirical method and prediction of corresponding chemical shifts with a Machine Learning (ML) model tuned for Pt complexes. The workflow was designed for the prediction of ¹⁹⁵ Pt chemical shifts of water-soluble Pt(II) and Pt(IV) anionic, neutral, and cationic complexes with halide, NO₂ ^- , (di)amino, and (di)carboxylate ligands with chemical shift values ranging from -6293 to 7090 ppm. The model offered an accuracy (normalized root-mean-square deviation/RMSD) of 1.08 %/145.02 ppm on the held-out test set.

Emerging role of non-coding RNAs in resistance to platinum-based anti-cancer agents in lung cancer

Platinum-based drugs are the first line of therapeutics against many cancers, including lung cancer. Lung cancer is one of the leading causes of cancer-related death worldwide. Platinum-based agents target DNA and prevent replication, and transcription, leading to the inhibition of cell proliferation followed by cellular apoptosis. About twenty-three platinum-based drugs are under different stages of clinical trials, among cisplatin, carboplatin, and oxaliplatin are widely used for the treatment of various cancers. Among them, cisplatin is the most commonly used drug for cancer therapy, which binds with RNA, and hinders the cellular RNA process. However, long-term use of platinum-based drugs can cause different side effects and has been shown to develop chemoresistance, leading to poor clinical outcomes. Chemoresistance became an important challenge for cancer treatment. Platinum-based chemoresistance occurs due to the influence of intrinsic factors such as overexpression of multidrug resistance proteins, advancement of DNA repair mechanism, degradation, and deactivation of intracellular thiols. Recently, epigenetic modifications, especially non-coding RNAs (ncRNAs) mediated gene regulation, grasp the attention for reversing the sensitivity of platinum-based drugs due to their reversible nature without altering genome sequence. ncRNAs can also modulate the intrinsic and non-intrinsic mechanisms of resistance in lung cancer cells. Therefore, targeting ncRNAs could be an effective approach for developing novel therapeutics to overcome lung cancer chemoresistance. The current review article has discussed the role of ncRNA in chemoresistance and its underlying molecular mechanisms in human lung cancer.

2: A Novel Potent Platinum(IV) Prodrug Enhances Chemo-Immunotherapy by Facilitating PD-L1 Degradation in the Cytoplasm and Cytomembrane

Platinum drugs as primary chemotherapy drugs have been applied to various cancer patients. However, their therapeutic applicability is limited due to the adverse effects and immunosuppression. To minimize the side effects and boost the immune response, we designed and synthesized platinum(IV) prodrugs that introduced BRD4 inhibitor JQ-1. Among them, CJ2 had the most potent therapeutic activity and less toxicity. With the introduction of ligand JQ-1, CJ2-reduced PD-L1 protein was found in the cytoplasm and cytomembrane for the first time. By interfering with the PD-L1 synthesis, CJ2 could arouse the immune system and promote CD8+ T cell infiltration. Meanwhile, CJ2 could accelerate PD-L1 degradation in the cytoplasm to block DNA damage repair. In vivo, CJ2 markedly suppressed tumor growth by reversing the immunosuppression microenvironment and enhancing DNA damage. These findings provide an effective approach to improve the selectivity and activity of the platinum drugs with elevated immune response.

Emerging platinum(0) nanotherapeutics for efficient cancer therapy

Platinum (Pt)-based chemotherapy has been necessary for clinical cancer treatment. However, traditional bivalent drugs are hindered by poor physicochemical properties, severe toxic side effects, and drug resistance. Currently, elemental Pt(0) nanotherapeutics (NTs) have emerged to tackle the dilemma. The inherent acid-responsiveness of Pt(0) NTs could help to improve tumor selectivity and alleviate toxic effects. Moreover, the metal nature of Pt facilitates the great combination of Pt(0) NTs with photothermal and photodynamic therapy and imaging-guided diagnosis. Based on recent important researches, this review provides an updated introduction to Pt(0) NTs. First, the challenges of traditional Pt-based chemotherapy have been outlined. Then, Pt(0) NTs with multiple applications of tumor theranostics have been overviewed. Furthermore, the combinations of Pt(0) NTs with other therapeutical modalities are introduced. Last but not least, we envision the possible challenges and prospects associated with Pt(0) NTs.

Metallo-Drugs in Cancer Therapy: Past, Present and Future

Cancer treatments which include conventional chemotherapy have not proven very successful in curing human malignancies. The failures of these treatment modalities include inherent resistance, systemic toxicity and severe side effects. Out of 50% patients administrated to chemotherapy, only 5% survive. For these reasons, the identification of new drug designs and therapeutic strategies that could target cancer cells while leaving normal cells unaffected still continues to be a challenge. Despite advances that have led to the development of new therapies, treatment options are still limited for many types of cancers. This review provides an overview of platinum, copper and ruthenium metal based anticancer drugs in clinical trials and in vitro/in vivo studies. Presumably, copper and ruthenium complexes have greater potential than Pt(II) complexes, showing reduced toxicity, a new mechanism of action, a different spectrum of activity and the possibility of non-cross-resistance. We focus the discussion towards past, present and future aspects.

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

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

Nanosized Janus AuNR-Pt Motor for Enhancing NIR-II Photoacoustic Imaging of Deep Tumor and Pt2+ Ion-Based Chemotherapy

Synthetic micro/nanomotors have great potential in deep tissue imaging and in vivo drug delivery because of their active motion ability. However, applying nanomotors with a size less than 100 nm to in vivo imaging and therapy is one of the core changes in this field. Herein, a nanosized hydrogen peroxide (H₂O₂)-driven Janus gold nanorod-platinum (JAuNR-Pt) nanomotor is developed for enhancing the second near-infrared region (NIR-II) photoacoustic (PA) imaging of deep tissues of tumors and for effective tumor treatment. The JAuNR-Pt nanomotor is prepared by depositing platinum (Pt) on one end of a gold nanorod with varying proportions of Pt shell coverage, including 10%, 25%, 50%, 75%, and 100%. The JAuNR-Pt nanomotor with Pt shell coverage proportions of 50% exhibits the highest diffusion coefficient (D_e), and it can rapidly move in the presence of H₂O₂. The self-propulsion of JAuNR-Pt nanomotor enhances cellular uptake, accelerates lysosomal escape, and facilitates continuous release of cytotoxic Pt²⁺ ions to the nucleus, causing DNA damage and cell apoptosis. The JAuNR-Pt nanomotor presents deep penetration and enhanced accumulation in tumors as well as high tumor treatment effect. Therefore, this work displays deep tumor imaging and an excellent antitumor effect, providing an effective tool for accurate diagnosis and treatment of diseases.

Therapeutic Effect of Platinum Nanoparticles on Atherosclerosis Research Model Based on Microfluidics and Determination of Injury

The atherosclerosis (AS) microenvironment plays an important role in pathogenicity, including blood flow and blood pressure, high cholesterol, high blood sugar, angiotensin II, tumor necrosis factor, and the like. The AS microfluidic model was established, and the fluid shear stress and cyclic stretching were set to 5.07 Pa and 1.17 Hz to simulate normal blood flow, respectively. The effects of different biochemical environments on endothelial cells (ECs) and cardiomyocytes were analyzed. The results confirmed that different biochemical environments had significant damage to ECs and cardiomyocytes. Subsequently, the further effect of ECs on cardiomyocytes in AS microenvironment was studied, and the results proved that ECs caused further damage to cardiomyocytes under AS biochemical factors. We used Pt nanoparticles (Pt NPs) to study the anti-AS efficiency. The results showed that the addition of Pt NPs played a particular role in the AS treatment of ECs in the AS microenvironment, and the protection for myocardial cells was achieved.

19F NMR Allows to Investigate the Fate of Platinum(IV) Prodrugs in Physiological Conditions

Pt(IV) prodrugs can overcome resistance and side effects of conventional Pt(II) anticancer therapies. By 19 F-labeling of a Pt(IV) prodrug (Pt-FBA, FBA = p -fluorobenzoate), the activation under physiological conditions could be investigated. It is found that, unlike single-electron reductants, multi-electron agents can efficiently promote the two electrons reduction of Pt(IV) to Pt(II). Moreover, the activation of Pt-FBA in cell lysate is highly dependent upon the type of cancer cells. When administered to E. coli , Pt-FBA is reduced intracellularly and free FBA can shuttle out of the cell. Interestingly, the reduction rate greatly increases by inducing metallothionein overexpression and is lowered by addition of Zn(II) ions. Finally, when injected into mice, Pt-FBA undergoes fast reduction in the bloodstream accompanied by metabolic degradation of FBA; nevertheless, unreduced Pt-FBA can accumulate to detectable levels in liver and kidneys. The proposed 19 F-NMR approach has the advantage of avoiding the interference of all background signals.

Dynamic nanoassembly-based drug delivery systems on the horizon

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

Biodistribution and efficacy of the anticancer drug, oxaliplatin palmitate acetate, in mice

Oxaliplatin palmitate acetate (OPA), a platinum (IV) oxaliplatin derivative, was previously designed with the aim to improve the platinum-based anti-cancer therapy. In this work, we further explore the potential of OPA in extensive in vitro and in vivo studies. OPA in pancreatic (BxPC3-luc), lung (NCI-H1993) and liver (Hep3B) cancer cell lines showed a higher toxicity in comparison to oxaliplatin. The in vitro release kinetic experiments of OPA from the nanoparticles (NPs) under sink conditions exhibited a very rapid profile. Furthermore, OPA cannot be considered a prodrug of oxaliplatin, based on the OPA intact molecule pharmacokinetic profile study in rats. The formation of oxaliplatin from the biodegradation of OPA ranges only from 5% to 7% and both drugs were rapidly eliminated from the plasma. Pharmacokinetics of OPA PLGA nanoparticles in mice showed that nanoparticles failed to prolong the release of OPA in the plasma and did not add any therapeutic benefit over OPA solution, as suggested by the rapid in vitro release of OPA from nanoparticles. In pancreatic xenograft BxPC3-luc cancer model, both OPA in solution and OPA nanoparticles inhibited the tumor growth, equally and significantly, as compared to oxaliplatin. In liver xenograft Hep3B cancer model, OPA solution and cisplatin demonstrated good and similar antitumor efficacy. In lung xenograft NCI-H1993 cancer model, OPA solution, with a significant antitumor efficacy, was superior to cisplatin, which did not differ from the vehicle. In conclusion, OPA may offer a promising advance in platinum-based chemotherapy against various forms of cancers in an adequate dose and schedule.

Synthesis and anticancer activity of mixed ligand 3d metal complexes

Our previously reported copper-based complexes of tropolone show nice antitumor effects, but with high cytotoxicity to normal cells, which is presumably caused by copper ions. Here, we managed to achieve this challenge by using other 3D metals to replace copper ions. We thus prepared four mononuclear 3D metal complexes [M(phen)L2] (M = Mn, Co, Ni, and Zn for 1-4, respectively). Complexes 1 and 4 show selectivity on different cancer cell lines with much lower cytotoxicity to normal cells than cisplatin. The anticancer effects for complexes 2 and 3 on the tested cancer cell lines are very poor. It revealed a tuning effect of different metal ions on the anticancer activities with those for Mn(II) and Zn(II) being much higher than those for Co(II) and Ni(II) in this system. Among them, complex 1 presents a best anticancer effect on HeLa cells comparable to cisplatin. It overcame the afore-mentioned shortage of high cytotoxicity to normal cells for the reported Cu(II) complexes. It revealed from the mechanistic studies that complex 1 mainly induces apoptosis through the mitochondrial pathway by increasing intracellular reactive oxygen species, releasing Ca2+, and activating Caspase 9 and proapoptotic gene Bax.

Nanoparticle-based drug delivery systems with platinum drugs for overcoming cancer drug resistance

Platinum drugs are commonly used in cancer therapy, but their therapeutic outcomes have been significantly compromised by the drug resistance of cancer cells. To this end, intensive efforts have been made to develop nanoparticle-based drug delivery systems for platinum drugs, due to their multifunctionality in delivering drugs, in modulating the tumor microenvironment, and in integrating additional genes, proteins, and small molecules to overcome chemoresistance in cancers. To facilitate the clinical application of these promising nanoparticle-based platinum drug delivery systems, this paper summarizes the common mechanisms for chemoresistance towards platinum drugs, the advantages of nanoparticles in drug delivery, and recent strategies of nanoparticle-based platinum drug delivery. Furthermore, we discuss how to design delivery platforms more effectively to overcome chemoresistance in cancers, thereby improving the efficacy of platinum-based chemotherapy.

Smart Microenvironment-Responsive Organocopper(II) Supramolecular Polymers to Regulate the Stability and Anticancer Efficacy by Different Substituents

The search for chemotherapeutic drugs with a high efficiency and low toxicity continues to be a challenge in tumor treatment for scientists. Organometallic supramolecular polymers are an attractive option to achieve this goal, not only due to the fact that they possess both advantages of metal complexes and nanostructures but also because they are usually sensitive to pH. Here, we report the design and synthesis of a series novel smart microenvironment-responsive organocopper(II) supramolecular polymers with various substituted ligands to regulate their stability and anticancer efficacy. The investigation of the possible mechanisms revealed that the organocopper(II) polymers enter cancer cells through endocytosis and then induce apoptosis of cancer cells. Furthermore, the in vivo anticancer efficacy study demonstrated that these organocopper(II) polymers inhibited the tumor growth effectively without damage to the major organs. Overall, the organocopper(II) supramolecular polymers present a promising pathway to achieve high-efficiency and low-toxicity chemotherapy.

Is GSH Chelated Pt Molecule Inactive in Anti-Cancer Treatment? A Case Study of Pt6 GS4

Platinum (Pt) drugs are widely used in anti-cancer treatment although many reports advocated that tumor cells could inactivate Pt drugs via glutathione-Pt (GSH-Pt) adducts formation. To date, GSH chelated Pt molecules have not been assessed in cancer treatment because GSH-Pt adducts are not capable of killing cancer cells, which is widely accepted and well followed. In this report, endogenous biothiol is utilized to precisely synthesize a GSH chelated Pt molecule (Pt₆ GS₄ ). This Pt₆ GS₄ molecule can be well taken up by aggressive triple negative breast cancer (TNBC) cells. Subsequently, its metabolites could enter nuclei to interact with DNA, finally the DNA-Pt complex triggers TNBC cell apoptosis via the p53 pathway. Impressively, high efficacy for anti-cancer treatment is achieved by Pt₆ GS₄ both in vitro and in vivo when compared with traditional first-line carboplatin in the same dosage. Compared with carboplatin, Pt₆ GS₄ keeps tumor bearing mice alive for a longer time and is non-toxic for the liver and kidneys. This work opens a route to explore polynuclear Pt compound with accurate architecture for enhancing therapeutic effects and reducing systemic toxicity.

Anticancer Melatplatin Prodrugs: High Effect and Low Toxicity, MT1-ER-Target and Immune Response In Vivo

Multitargeted therapy could rectify various oncogenic pathways to block tumorigenesis and progression. The combination of endocrine-, immune-, and chemotherapy might exert a highly synergistic effect against certain tumors. Herein, a series of smart Pt(IV) prodrugs 3-6, named Melatplatin, were rationally designed not only to multitarget DNA, MT1, and estrogen receptor (ER) but also to activate immune response. Melatplatin, conjugating first-line chemotherapeutic Pt drugs with human endogenous melatonin (MT), significantly enhanced drug efficacy especially in ER high-expression (ER⁺) cells, among which 3 presented the most potent cytotoxicity toward ER⁺ MCF-7 with nanomolar IC₅₀ values 100-fold lower than cisplatin. Melatplatin could bind well to melatonin receptor (MT1) according to molecular docking. Besides, 3 evidently increased intracellular accumulation and DNA damage, upregulated γH2AX and P53, and silenced NF-κB to induce massive apoptosis. Most strikingly, 3 effectively inhibited tumor growth and attenuated systemic toxicity compared to cisplatin in vivo, promoting lymphocyte proliferation in spleen to achieve immune modulation.

Dynamic supraparticles for the treatment of age-related diseases

Age-related diseases (ARDs) are arising as a major threat to public health in our fast-aging society. Current development of nanomedicine has sparked much optimism toward ARDs management by improving drug delivery and controlled drug release. However, effective treatments for ARDs, such as cancer and Alzheimer's diseases (AD), are still lacking, due to the complicated pathological features of ARDs including multifactorial pathogenesis, intricate disease microenvironment, and dynamic symptom manifestation. Recently, dynamic supraparticles (DS), which are reversibly self-assembled functional nanoparticles, have provided a novel strategy for combating ARDs. Besides the intrinsic advantages of nanomedicine including multifunctional and multitarget, DS are capable of dynamic structural reconfiguration upon certain stimulation, creating another layer of maneuverability that allows programmed response to the spatiotemporal alterations of ARDs during progression and treatment. In this review, we will overview the challenges faced by ARDs management, and discuss the unique opportunities brought by DS. Then, we will summarize the designed synthesis of DS for ARDs treatment. Finally, we will dissect the therapeutic targets in ARDs that can be exploited by DS, and present the encouraging advances in this field. Hopefully, this review will bridge our knowledge of the design principle of DS and ARDs management, which may inspire the future development of potent theranostic agents to improve the healthcare.

Progress and Prospects of Graphdiyne-Based Materials in Biomedical Applications

Graphdiyne is a new member of the family of carbon-based nanomaterials that possess two types of carbon atoms, sp- and sp² -hybridized carbon atoms. As a novel 2D carbon-based nanomaterial with unique planar structure, such as uniformly distributed nanopores and large conjugated structure, graphdiyne has shown many fascinating properties in mechanics, electronics, and optics since it was first experimentally synthesized in 2010. Up to now, graphdiyne and its derivatives have been reported to be successfully applied in many areas, such as catalysis, energy, environment, and biomedicine, due to these excellent properties. Herein, the current research progress of graphdiyne-based materials in biomedical fields is summarized, including biosensing, biological protection, cancer therapy, tissue engineering, etc. The advantages of graphdiyne and its derivatives are presented and compared with other carbon-based materials. Considering the potential biomedical and clinical applications of graphdiyne-based materials, the toxicity and biocompatibility are also discussed based on current studies. Finally, future perspectives and possible biomedical applications of graphdiyne-based materials are also discussed.

Locked and Loaded: Ruthenium(II)-Capped Cucurbit[n]uril-Based Rotaxanes with Antimetastatic Properties

We report here the first coupling of Ru(II) units with cucurbit[6/7]uril-based pseudorotaxane ligands meant for biological application. The resulting ruthenium-capped rotaxanes were fully characterized, and a structure of one supramolecular system was determined by X-ray diffraction. Because the biological properties of Ru-based metallodrugs are tightly linked to the ligand-exchange processes, the effect of salt concentration on the hydrolysis of chlorides from the Ru(II) center was monitored by using ¹H NMR spectroscopy. The biological activity of Ru(II)-based rotaxanes was evaluated for three selected mammalian breast cell lines, HBL-100, MCF-7, and MDA-MB-231. The antimetastatic activity of the assembled cationic Ru(II)-rotaxane systems, evaluated in migration assays against MCF-7 and MDA-MB-231 cell lines, is notably enhanced compared to that of RAPTA-C, a reference that was used. The indicated synergistic effect of combining Ru(II) with a pseudorotaxane unit opens a new direction in searching for anticancer supramolecular metallodrugs.

Cisplatin: The first metal based anticancer drug

Cisplatin or (SP-4-2)-diamminedichloridoplatinum(II) is one of the most potential and widely used drugs for the treatment of various solid cancers such as testicular, ovarian, head and neck, bladder, lung, cervical cancer, melanoma, lymphomas and several others. Cisplatin exerts anticancer activity via multiple mechanisms but its most acceptable mechanism involves generation of DNA lesions by interacting with purine bases on DNA followed by activation of several signal transduction pathways which finally lead to apoptosis. However, side effects and drug resistance are the two inherent challenges of cisplatin which limit its application and effectiveness. Reduction of drug accumulation inside cancer cells, inactivation of drug by reacting with glutathione and metallothioneins and faster repairing of DNA lesions are responsible for cisplatin resistance. To minimize cisplatin side effects and resistance, combination therapies are used and have proven more effective to defect cancers. This article highlights a systematic description on cisplatin which includes a brief history, synthesis, action mechanism, resistance, uses, side effects and modulation of side effects. It also briefly describes development of platinum drugs from very small cisplatin complex to very large next generation nanocarriers conjugated platinum complexes.

Versatile Pt NCs-based chemotherapeutic agents significantly induce the apoptosis of cisplatin-resistant non-small cell lung cancer

Recently, the incidence of lung cancer is generally rising along with air pollution and smoking, and non-small cell lung cancer (NSCLC) accounts for nearly 85% among all lung cancer diagnoses. With the development of chemotherapy, the drug resistance rate of common platinum-based chemotherapeutic drugs (like cisplatin) is gradually increased, which seriously affects the chemotherapy efficiency and survival rate of patients. In this study, polyethylenimine caged platinum nanoclusters (PEI-caged Pt NCs) were proposed as a new chemotherapeutic agent to apply in the treatment of NSCLC, choosing the classical cisplatin-resistant A549/DDP cells and normal A549 cells as targets. It was found that our Pt NCs-based chemotherapeutic drugs showed its preferable therapeutic effect in cisplatin-resistant NSCLC through the results of confocal microscopic images, cell counting kit-8 test, cell apoptosis assay and western blot. Most importantly, in the cisplatin-resistance A549/DDP cells, this kind of agents could enter the nucleus obviously, and emerged a superior inhibitory and apoptotic effects than A549 via activating p53 protein and the related signaling pathways. Comparing with the traditional chemotherapy drugs, these Pt NCs-based chemotherapeutic agents exhibit great potential and advantages in the treatment and diagnosis of NSCLC regardless of the therapeutic effect or toxic side effects, especially the drug resistance.

Tumor microenvironment-responsive docetaxel-loaded micelle combats metastatic breast cancer

Efficient tumor-targeting drug delivery systems are urgently needed for treating metastatic breast cancer. In this work, a docetaxel (DTX)-loaded micelle (pDM) as the tumor-microenvironment-responsive delivery platform is developed. The micelle is composed of a pH-sensitive amphiphilic copolymer, poly((1,4-butanediol)-diacrylate-β-N,N-diisopropylethylenediamine)-polyethyleneimine (BD-PEI), and a matrix metalloproteinase (MMP)-responsive polymer, poly((1,4-butanediol)-diacrylate-β-N,N-diisopropylethylenediamine)-peptide-polyethylene glycol (PEG) (BD-peptide-PEG). The PEG block of BD-peptide-PEG will be split by MMPs at the tumor microenvironment, which leads to the change of the surface charge and particle size of the micelle to more positive and smaller one. Owing to this transformation and enhanced permeability and retention (EPR) effect, pDM delivers more DTX into tumor tissues and is internalized more efficiently by tumor cells than the non-MMP-sensitive micelles in the 4T1 tumor-bearing mice model. In addition, DTX is released in acidic endo/lysosomes due to the dissociation of the micelle, triggered by the protonation of the hydrophobic block of BD-PEI. As a result, the DTX-loaded micelle inhibits primary tumor growth and pulmonary metastasis effectively. Thus, this pH/MMP-dual-sensitive drug delivery system, which simultaneously attains three keypoints: prolonged circulation time, directional and efficient uptake into tumor cells, and speedy intracellular drug release, is a promising strategy for metastatic breast cancer therapy.

Controlled synthesis and assembly of ultra-small nanoclusters for biomedical applications

This Minireview summarizes recent advances in the controlled synthesis, assembly, and biomedical applications of ultra-small nanoclusters.

Antibacterial Performance of TiCaPCON Films Incorporated with Ag, Pt, and Zn: Bactericidal Ions Versus Surface Microgalvanic Interactions

It is very important to prevent bacterial colonization at the early postoperative stages. There are four major strategies and their corresponding types of antibacterial surfaces specifically designed to fight infection: bactericide release, anti-adhesion, pH-sensitive, and contact-killing. Herein, we aimed at determining the antibacterial efficiency of different types of bactericidal ions and revealing the possible contribution of surface microgalvanic effects arising from a potential difference on heterogeneous surfaces. We considered five types of TiCaPCON films, with Ag, Zn, Pt, Ag + Zn, and Pt + Zn nanoparticles (NPs) on their surface. The Ag-modified film demonstrated a pronounced antibacterial effect at a very low Ag ion concentration of 0.11 ppb in physiological solution that was achieved already after 3 h of immersion in Escherichia coli ( E. coli) bacterial culture. The Zn-containing sample also showed a noticeable antibacterial effect against E. coli and Staphylococcus aureus ( S. aureus) strains, wherein the concentration of Zn ions was 2 orders of magnitude higher (15 ppb) compared with the Ag ions. The presence of Ag NPs accelerated the leaching of Zn ion out of the TiCaPCON-Ag-Zn film, but no synergistic effect of the simultaneous presence of the two bactericidal components was observed. After the incubation of the samples with Ag, Zn, and Ag + Zn NPs in E. coli and S. aureus suspensions for 24 and 8 h, respectively, all bacterial cells were completely inactivated. The Pt-containing film showed a very low Pt ion release, and therefore the contribution of this type of ions to the total bactericidal effect could be neglected. The results of the electrochemical studies and Kelvin probe force microscopy indicated that microgalvanic couples were formed between the Pt NPs and the TiCaPCON film, but no noticeable antibacterial effect against either E. coli or S. aureus strains was observed. All ion-modified samples provided good osteoblastic cell attachment, spreading, and proliferation and therefore were concluded to be nontoxic for cells. In addition, the TiCaPCON films with Ag, Pt, and Zn NPs on their surface demonstrated good osteoconductive characteristics.