Dual Drug Backboned Shattering Polymeric Theranostic Nanomedicine for Synergistic Eradication of Patient-Derived Lung Cancer

Carrier-free prodrug nanoparticles based on dasatinib and cisplatin for efficient antitumor in vivo

Carrier-free drug self-delivery systems consisting of amphiphilic drug-drug conjugate (ADDC) with well-defined structure and nanoscale features have drawn much attention in tumor drug delivery. Herein, we report a simple and effective strategy to prepare ADDC using derivatives of cisplatin (CP) and dasatinib (DAS), which further self-assembled to form reduction-responsive nanoparticles (CP-DDA NPs). DAS was modified with succinic anhydride and then connected with CP derivative by ester bonds. The size, micromorphology and in vitro drug release of CP-DDA NPs were characterized. The biocompatibility and bioactivity of these carrier-free nanoparticles were then investigated by HepG2 cells and H22-tumor bearing mice. In vitro and in vivo experiments proved that CP-DDA NPs had excellent anti-tumor activity and significantly reduced toxicities. This study provides a new strategy to design the carrier-free nanomedicine composed of CP and DAS for synergistic tumor treatment.

Reduction-Sensitive Fluorinated-Pt(IV) Universal Transfection Nanoplatform Facilitating CT45-Targeted CRISPR/dCas9 Activation for Synergistic and Individualized Treatment of Ovarian Cancer

Compared to traditional clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system, CRISPR/dead Cas9 (dCas9) system can precisely regulate endogenous gene expression without damaging the host gene, representing a greater potential for cancer therapy. Cancer/testis antigen 45 (CT45) is proved to enhance platinum-based chemosensitivity for individualized ovarian cancer therapy. However, the development of a single nanocarrier codelivering CRISPR/dCas9 system and chemotherapeutics for synergistic cancer therapy still faces challenges. Herein, a reduction-sensitive fluorinated-Pt(IV) universal transfection nanoplatform (PtUTP-F) is developed for the CT45-targeted CRISPR/dCas9 activation to achieve synergistic and individualized treatment of ovarian cancer. Overcoming multiple physiological barriers, PtUTP-F condensed gene can efficiently transfect into different cells including 293T cells, A2780, SKOV3, A549, and A2780/cisplatin (DDP) cancer cells, which is superior to Lipofectamine 6000. With the responsive release of gene and Pt(II) in the intracellular reducing microenvironment, PtUTP-F/dCas9-CT45 can generate CRISPR/dCas9 activation of CT45 expression for protein phosphatase 4C (PP4C) activity inhibition to hinder the DNA repair pathway and thus enhances the sensitivity to Pt(II) drugs for individualized A2780 tumor therapy. The PtUTP-F not only represents a powerful nanoplatform for CRISPR/dCas9 system delivery but also initiates a novel strategy for synergistic and individualized treatment of CRISPR/dCas9-based gene therapy with chemotherapy.

Linear-Dendritic Polymer-Platinum Complexes Forming Well-Defined Nanocapsules for Acid-Responsive Drug Delivery

Polymeric nanocapsules hold considerable applications in cancer drug delivery, but the synthesis of well-defined nanocapsules with a tunable drug release property remains a significant challenge in fabrication. Herein, we demonstrate a supramolecular complexation strategy to assemble small molecular platinum (Pt) compounds into well-defined nanocapsules with high drug loading, acidity-sensitivity, and tunable Pt releasing profile. The design utilizes poly(ethylene glycol)-dendritic polylysine-G4/amides to complex with Pt compounds, forming stable nanocapsules with diameters approximately ∼20 nm and membrane thickness around several nanometers. The stability, drug content, and release profiles are tunable by tailoring the dendritic structure. The designated polymer-Pt nanocapsules, PEG-G4/MSA-Pt, showed sustained blood retention, preferential tumor accumulation, enhanced cellular uptake, lysosomal drug release, and nuclear delivery capability. PEG-G4/MSA-Pt showed enhanced antitumor efficacy compared to free cisplatin and other nanocapsules, which stopped the progression of both A549 cell xenografts and patient-derived xenografts (PDXs) of hepatocellular carcinoma on a mice tumor model. Thus, we believe this strategy is promising for developing Pt-based nanomedicine for cancer drug delivery.

Nanoparticulation of Prodrug into Medicines for Cancer Therapy

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Chemotherapy-enabled/augmented cascade catalytic tumor-oxidative nanotherapy

Catalytic cascade transformations, which occur in spatially constrained tumor environment to generate therapeutic moieties from prodrugs or intrinsic species, are highly desirable for precise cancer therapy. Nevertheless, it is high challenging to engineer a cascade nanoreactor with tumor microenvironment (TME)-responsive capability for synergistic tumor therapy. Inspired by the biocatalytic cascades in biological processes, here, a tumor-specific nanoreactor was established to activate cascade reactions for oxidative stress-augmented chemotherapy by the integration of an artificial enzyme, Pt(IV)-based prodrug (Pt(IV)), with Cu(II)-based metal-organic frameworks (CuMOF). Upon internalization of CuMOF@Pt(IV) by tumor cells, in addition to chemotherapeutic effect, the activated cisplatin by glutathione (GSH) reduction is capable of acting as an artificial enzyme to elevate the hydrogen peroxide (H₂O₂) level through cascade reactions for augmenting the therapeutic efficacy of Cu⁺-mediated chemodynamic therapy (CDT). Meanwhile, CuMOF@Pt(IV) specifically deplete overexpressed GSH at tumor sites, thus amplifying tumor oxidative stress, and finally leading to augmented antitumor efficacy. The orchestrated cooperative effect of chemotherapy and oxidative stress presents splendid therapeutic efficacy on tumor-bearing mice with negligible adverse effects. Therefore, this cascade nanoreactor provides exciting opportunities to develop complementary therapeutic modalities for precise cancer treatment.

Multifaceted roles of long non-coding RNAs in triple-negative breast cancer: biology and clinical applications

Triple-negative breast cancer (TNBC) is a heterogeneous breast cancer subtype that lacks targeted therapy due to the absence of estrogen, progesterone, and HER2 receptors. Moreover, TNBC was shown to have a poor prognosis, since it involves aggressive phenotypes that confer significant hindrance to therapeutic treatments. Recent state-of-the-art sequencing technologies have shed light on several long non-coding RNAs (lncRNAs), previously thought to have no biological function and were considered as genomic junk. LncRNAs are involved in various physiological as well as pathological conditions, and play a key role in drug resistance, gene expression, and epigenetic regulation. This review mainly focuses on exploring the multifunctional roles of candidate lncRNAs, and their strong association with TNBC development. We also summarise various emerging research findings that establish novel paradigms of lncRNAs function as oncogenes and/or tumor suppressors in TNBC development, suggesting their role as prospective therapeutic targets.

An assessment of in-vitro and in-vivo evaluation methods for theranostic nanomaterials

Nanoparticles (NPs) as nanocarriers have emerged as novel and promising theranostic agents. The term theranostics revealed the properties of NPs capable of diagnosing the disease at an early stage and/or treating the disease. Such NPs are usually developed employing a surface engineering approach. The theranostic agents comprise NPs loaded with a drug/diagnostic agent that delivers it precisely to the target site. Theranostics is a field with promising results in enhancing therapeutic efficacy facilitated through higher payload at the targeted tissue, reduced dose, and dose-dependent side effects. However, controversies in terms of toxicity and size-dependent properties have often surfaced for NPs. Thus, a stringent in-vitro and in-vivo evaluation is required to develop safe and non-toxic NPs as theranostic agents. The review also focuses on the various entry points of NPs in the human system and their outcomes, including toxicity. It elaborates the evaluation criteria to ensure the safe use of NPs for diagnostic and therapeutic purposes.

Metal-Coordinated Supramolecular Self-Assemblies for Cancer Theranostics

Metal-coordinated supramolecular nanoassemblies have recently attracted extensive attention as materials for cancer theranostics. Owing to their unique physicochemical properties, metal-coordinated supramolecular self-assemblies can bridge the boundary between traditional inorganic and organic materials. By tailoring the structural components of the metal ions and binding ligands, numerous multifunctional theranostic nanomedicines can be constructed. Metal-coordinated supramolecular nanoassemblies can modulate the tumor microenvironment (TME), thus facilitating the development of TME-responsive nanomedicines. More importantly, TME-responsive organic-inorganic hybrid nanomaterials can be constructed in vivo by exploiting the metal-coordinated self-assembly of a variety of functional ligands, which is a promising strategy for enhancing the tumor accumulation of theranostic molecules. In this review, recent advancements in the design and fabrication of metal-coordinated supramolecular nanomedicines for cancer theranostics are highlighted. These supramolecular compounds are classified according to the order in which the coordinated metal ions appear in the periodic table. Furthermore, the prospects and challenges of metal-coordinated supramolecular self-assemblies for both technical advances and clinical translation are discussed. In particular, the superiority of TME-responsive nanomedicines for in vivo coordinated self-assembly is elaborated, with an emphasis on strategies that enhance the accumulation of functional components in tumors for an ideal theranostic outcome.

Charge-Reversal Polymer Nano-modulators for Photodynamic Immunotherapy of Cancer

Nanomedicine can regulate the balance between cytotoxic T lymphocytes (CTLs) and suppressive regulatory T lymphocytes (Tregs), which however has been rarely exploited for cancer immunotherapy. We report a charge-reversal polymer nano-modulator (SP_DMC N) activated by tumor microenvironment (TME) for photodynamic immunotherapy of cancer. SP_DMC N is constructed by conjugating an immunomodulator (demethylcantharidin, DMC) to the side chains of a photodynamic polymer via an acid-liable linker. The negative charge of SP_DMC N ensures its high stability in blood circulation and ideal tumor accumulation; exposure to acidic TME reverses its surface charge to positive, enhancing tumor penetration and locally releasing DMC. Upon near-infrared photoirradiation, SP_DMC N generates singlet oxygen to ablate tumors and promote maturation of dendritic cells. Released DMC inhibits protein phosphatase 2 (PP2A) activity and decreases Tregs differentiation. Such combinational action induces a sharp increase in CTL/Treg ratio in TME and effectively inhibits both primary and distant tumors in living mice.

Dynamic precise dual-drug-backboned nano-prodrugs for selective chemotherapy

To achieve an ideal drug delivery platform with precise composition and high tumor selectivity, the PEGylated dual-drug backboned prodrug was synthesized via the copolymerization between diamine monomer of ortho ester and cisplatin- demethylcantharidin conjugate (Pt(IV)-1), and then terminated by mPEG550-active ester. The amphipathic prodrug could self-assemble into nano-prodrugs, which endowed the precise structure and high drug loading. Moreover, the nano-prodrugs exhibited physicochemical stability at physiological pH (7.4) for stable blood circulation, DePEGylation and dynamic size change for selective tumor accumulation and enhanced cellular internalization at tumoral extracellular pH (6.8), and efficient drug release for synergetic apoptosis and cytotoxicity at tumoral intracellular pH (5.0)/glutathione. Thus, the precise dual-drug backboned nano-prodrugs with detachable PEGylation, dynamic size change and efficient drug release could be potentially translated for clinically selective cancer treatment. STATEMENT OF SIGNIFICANCE: Few nanomedicines have been clinically used for cancer treatment and little progress has been made in the last decades due to the unprecise composition and unsatisfactory tumor selectivity. Herein, the PEGylated dual-drug backboned nano-prodrugs were successfully constructed by rational design and endowed the defined structure, precise drug ratio, extraordinary high drug loading and reduction/pH dual sensitivity. The nano-prodrugs further exhibited the stable storage and blood circulation through PEGylation and low critical micelle concentration, enhanced tumor accumulation and cellular uptake via extracellular DePEGylation and dynamic size translation, and synergetic cytotoxicity via intracellular efficient drug release, respectively. This study can open a new avenue for easy industrial manufacture and quality control, and highly selective chemotherapy appealing for clinical translation. .

Nano-assembly of ursolic acid with platinum prodrug overcomes multiple deactivation pathways in platinum-resistant ovarian cancer

As the most common cause of gynecological cancer-related deaths worldwide, ovarian cancer requires novel therapy strategies. Pt(ii)-Based antitumor drugs (e.g. cisplatin) are one of the most successful and frequently used drugs in ovarian cancer chemotherapy at present. However, drug resistance and severe side effects are the major problems in cancer treatment. Herein, the design of a reduction responsive platinum(iv) (Pt(iv))/ursolic acid (UA)/polyethylene glycol (PEG) dual prodrug amphiphile (Pt(iv)-UA-PEG) to treat cisplatin-resistant ovarian cancer is reported for the first time. Pt(iv)-UA-PEG could self-assemble into nanoparticles (Pt(iv)-UA NPs) with a fixed and precise Pt/UA ratio, and a constantly high content of drugs. Pt(iv)-UA NPs could be efficiently taken up by cisplatin-resistant ovarian cancer cells and release the drug in intracellular reductive and acidic environments. In vitro studies show that the released UA and cisplatin have different anticancer mechanisms, and their synergistic effects overcome the detoxification and anti-apoptotic mechanisms of cancer cells. Furthermore, the in vivo results indicate that Pt(iv)-UA NPs have a prolonged blood circulation time, enhanced tumor accumulation, and significantly improved antitumor efficacy in A2780/DDP tumor-bearing mice, without causing any side effects. In summary, our results demonstrate that the development of the stimuli-responsive dual prodrug amphiphile nano-assembly provides a new strategy to overcome drug resistance.

Legumain-induced intracerebrally crosslinked vesicles for suppressing efflux transport of Alzheimer's disease multi-drug nanosystem

Brain barrier is both a protective permeability hurdle and a limitation site where therapeutic agents are excluded to enter the target region. Designing drug vehicle to overcome this notorious barrier bottle is challenging. Herein, we construct a stimuli-responsive self-assembled nanovesicle that delivers water-soluble drugs to prevent the efflux transport of brain barriers by responding to the endogenously occurring signals in Alzheimer's disease (AD) brain microenvironment. Once stimuli-responsive vesicles are accumulated in intracerebrally, the intrinsically occurring legumain endopeptidase cleaves the Ac-Ala-Ala-Asn-Cys-Asp (AK) short peptide on the drug vesicles to expose the 1,2 thiol amino group to cyclize with the cyano groups on 2-cyano-6-aminobenzothiazole (CABT) of the chaperone vesicles, thus triggering the formation of cross-linked micrometre-scale vesicles. Such a structural alteration completely prevents further brain barriers efflux. The superior neuroprotective capacity of cross-linked vesicles is validated in senescence accelerated mouse prone 8 (SAMP8). This smart multi-drug delivery vesicle is promising to serve as a powerful system for AD treatment and can be adapted for the therapy of other central nervous system (CNS) disorders.

Nanotechnology: Breaking the Current Treatment Limits of Lung Cancer

Lung cancer is one of the most rapidly growing malignancies in terms of morbidity and mortality. Although traditional treatments have been used for more than 50 years, it is still far from solving the problems of postoperative risks and systemic toxicity. Emerging targeting and immunotherapy are developing continuously and are gaining recognition; eventually, they face the inevitable challenge of drug resistance. Nanotechnology has several important effects on lung cancer treatment, owing to its unique properties. Several nanoparticle-based treatments have successfully become cancer treatments. Good biocompatibility with higher specific surface area can carry substantial amounts of lung cancer treatment medications while avoiding medication toxicity; editable and modified characteristics give rise to multifunctional nanomedicines; excellent photoelectric effects make lung cancer a multimodal treatment. This article summarizes the breakthroughs achieved by nanotechnology, targeted therapy, and immunotherapy, reflecting the importance and necessity of nanotechnology in the treatment of lung cancer.

Photoresponsive metallopolymer nanoparticles for cancer theranostics

Over the past decades, transition metal complexes have been successfully used in anticancer phototherapies. They have shown promising properties in many different areas including photo-induced ligand exchange or release, rich excited state behavior, and versatile biochemical properties. When encorporated into polymeric frameworks and become part of nanostructures, photoresponsive metallopolymer nanoparticles (MPNs) show enhanced water solubility, extended blood circulation and increased tumor-specific accumulation, which greatly improves the tumor therapeutic effects compared to low-molecule-weight metal complexes. In this review, we aim to present the recent development of photoresponsive MPNs as therapeutic nanomedicines. This review will summarize four major areas separately, namely platinum-containing polymers, zinc-containing polymers, iridium-containing polymers and ruthenium-containing polymers. Representative MPNs of each type are discussed in terms of their design strategies, fabrication methods, and working mechanisms. Current challenges and future perspectives in this field are also highlighted.

Tailoring Supramolecular Prodrug Nanoassemblies for Reactive Nitrogen Species-Potentiated Chemotherapy of Liver Cancer

The development of a controllable reactive nitrogen species (RNS) generation system for cancer treatment has remained elusive. Herein, a supramolecular prodrug nanoassemblies (SPNA) strategy that co-delivers a nitric oxide (NO) donor and a superoxide anion (O₂^•-) inducing chemotherapeutic agent was reported for RNS-potentiated chemotherapy. The mole ratio of platinum(IV) prodrug and NO donor could be precisely tailored in SPNA_Pt/NO. Platinum(II) and NO would be released intracellularly to produce a highly toxic RNS, peroxynitrite anion (ONOO^-). The levels of glutathione reductase (GR) and xeroderma pigmentosum group A (XPA) were down-regulated by ONOO^-, thus synergistically decreasing detoxification and blocking DNA damage repair of Pt-based chemotherapy. The RNS-potentiated efficacy of SPNA_Pt/NO was validated on subcutaneous hepatoma xenograft models and an orthotopic cisplatin-resistant hepatoma model. This co-delivery strategy of NO donor and O₂^•- inducing chemotherapeutic agents for RNS-mediated therapy provides an insightful direction for cancer treatment.

Platinum-Containing Supramolecular Drug Self-Delivery Nanomicelles for Efficient Synergistic Combination Chemotherapy

Supramolecular drug self-delivery systems (SDSDSs) involving active drugs as building blocks linked by supramolecular interactions have been well defined as an advanced chemotherapy strategy. However, the lack of detecting release of drugs from SDSDSs at specific tumor sites inevitably leads to unsatisfactory therapeutic effects, owing to the lack of information regarding the administration of these drugs. In this work, predesigned platinum-containing supramolecular drug self-delivery nanomicelles (SDSDNMs) were employed to synchronously realize drug monitoring by computed tomography imaging, immediately reflecting the evolution of drug release and real-time treatment at the tumor site. The appropriate administration dosage (1.2 mg mL^-1,100 μL) and the injection interval (once every 3 days) needed to guide the antitumor activity of SDSDNMs were then defined, thereby attaining the aim of efficient synergistic combination chemotherapy. In vivo tumor inhibition and histological analyses showed that SDSDNMs exhibited a strong tumor inhibition effect and good safety with respect to normal organs. Such a supramolecular drug self-delivery strategy with monitored functions may offer new potential opportunities for application in the field of synergistic combination chemotherapy.

Fabricating nanoparticles co-loaded with survivin siRNA and Pt(IV) prodrug for the treatment of platinum-resistant lung cancer

Resistance to platinum agents is a crucial challenge in the treatment of cancer using platinum drugs. To overcome the resistance of cells, the survivin protein is supposed to be decreased, since it has previously been found to be overexpressed in drug-resistant cancer cells in anti-apoptosis pathways, while the intracellular effective platinum accumulation should be increased. In the present work, a protamine/hyaluronic acid nanocarrier was used to load survivin siRNA with Pt(IV) loaded outside the coated polyglutamic acid (PGA) by chemical conjugation. The siRNA was released from the co-loaded nanoparticle prior to Pt(IV), in this way, the expression of survivin protein was effectively reduced, which, in turn, could avoid the anti-apoptosis of drug resistant cells. Here, Pt(IV) displayed a sustained release effect and gradually reduced to the toxic Pt(II) species, which reduced drug efflux and enhance apoptosis of the cancer cells. In vitro studies demonstrated that co-loaded nanoparticles resulted in similar cell killing performance in A549/DDP cells (cisplatin resistant) compared with non-siRNA loaded nanoparticles in A549 cells (cisplatin sensitive). NP-siRNA/Pt(IV) exhibited a greatly improved therapeutic effect (TIR, 82.46%) in a nude mice A549/DDP tumor model, with no serious adverse effects observed. Thus, co-loading of Pt(IV) and survivin siRNA nanoparticles could reverse cisplatin resistance and therefore has promising prospects for efficient cancer chemotherapy.

Fighting against drug-resistant tumors by the inhibition of γ-glutamyl transferase with supramolecular platinum prodrug nano-assemblies

Pt(ii)-based antitumor drugs (e.g. cisplatin and oxaliplatin) are one of the most successful and frequently used drugs in cancer chemotherapy at present. However, drug resistance and severe side effects are the major problems in the application of platinum drugs. Detoxification of Pt(ii) drugs is one of the most important mechanisms of drug resistance. Herein, a supramolecular Pt(iv) prodrug nano-assembly delivery system is designed and used to encapsulate a γ-glutamyl transferase (GGT) inhibitor (OU749) (Pt-CD/Dex-Ad@OU nano-assemblies) for the synergistic chemotherapy of cisplatin-resistant cancer. Pt-CD/Dex-Ad@OU nano-assemblies could be efficiently taken up by cisplatin-resistant cancer cells and release a drug in the intracellular reductive environment. The Pt-CD/Dex-Ad@OU nano-assemblies can efficiently suppress the expression of GGT, depleting GSH and augmenting ROS via the reduction of the Pt(iv) prodrug. Thereby, by breaking the redox balance the detoxification and antiapoptosis mechanisms of Pt(ii) drugs can be overcome. Thereafter, the excellent therapeutic efficacy of Pt-CD/Dex-Ad@OU nano-assemblies is validated on a cisplatin-resistant human non-small cell lung cancer (A549/DDP) model. Furthermore, the inhibition of GGT protein is expected to reduce the nephrotoxicity of cisplatin. Collectively, this study provides a promising strategy to break the redox balance for overcoming drug resistance and maximizing the efficacy of platinum-based cancer therapy.

Synthesis Characterization of Platinum (IV) Complex Curcumin Backboned Polyprodrugs: In Vitro Drug Release Anticancer Activity

The conventional mono-chemotherapy still suffers from unsatisfied potency for cancer therapy due to tumor heterogeneity and the occurrence of drug resistance. Combination chemotherapy based on the nanosized drug delivery systems (nDDSs) has been developed as a promising platform to circumvent the limitations of mono-chemotherapy. In this work, starting from cisplatin and curcumin (Cur), we prepared a dual drug backboned shattering polymeric nDDS for synergistic chemotherapy. By in situ polymerization of the Cur, platinum (IV) complex-based prodrug monomer (DHP), L-lysine diisocyanate (LDI), and then conjugation with a hydrophilic poly (ethylene glycol) monomethyl ether (mPEG) derivative, a backbone-type platinum (IV) and Cur linkage containing mPEG-poly(platinum-co-Cur)-mPEG (PCPt) copolymer was synthesized. Notably, the platinum (IV) (Pt (IV)) and Cur were incorporated into the hydrophobic segment of PCPt with the fixed drugs loading ratio and high drugs loading content. The batch-to-batch variability could be decreased. The resulting prodrug copolymer then self-assembled into nanoparticles (PCPt NPs) with an average diameter around 100 nm, to formulate a synergetic nDDS. Importantly, PCPt NPs could greatly improve the solubility and stability of Cur. In vitro drug release profiles have demonstrated that PCPt NPs were stable in PBS 7.4, rapid burst release was greatly decreased, and the Pt and Cur release could be largely enhanced under reductive conditions due to the complete dissociation of the hydrophobic main chain of PCPt. In vitro cell viability test indicated that PCPt NPs were efficient synergistic chemotherapy units. Moreover, PCPt NPs were synergistic for cisplatin-resistant cell lines A549/DDP cells, and they exhibited excellent reversal ability of tumor resistance to cisplatin. This work provides a promising strategy for the design and synthesis of nDDS for combination chemotherapy.

Development of a novel oxidative stress-amplifying nanocomposite capable of supplying intratumoral H2O2 and O2 for enhanced chemodynamic therapy and radiotherapy in patient-derived xenograft (PDX) models

Radiotherapy (RT) is a potent approach to cancer treatment, but the tumor microenvironment (TME) in solid tumors is often highly hypoxic and contains high levels of antioxidant enzymes, thereby reducing the RT efficacy. In this study, we developed an oxidative stress amplifier (termed CFM) capable of self-sufficient H2O2 and O2 delivery that can be used in concert with RT and chemodynamic therapy (CDT) to treat tumors in patient-derived xenograft (PDX) model systems. Upon exposure to the hypoxic and acidic TME, CFM undergoes rapid degradation that results in the release of Fe3+, Ca2+, O2, and H2O2. Glutathione can subsequently reduce Fe3+ to Fe2+, which is then able to react with H2O2via the Fenton reaction to yield high levels of hydroxyl radicals which subsequently damage mitochondria. CaO2-derived O2 also modulates intratumoral hypoxia, while excessive Ca2+ levels within mitochondria result in apoptotic cell death. Altogether, these properties sensitize PDX tumors to RT. Importantly, the Fe, Zn, and Ca generated by CFM degradation are essential elements in humans. Altogether, these properties make this approach to oxidative stress amplification a promising means of amplifying oxidative stress within tumors while overcoming hypoxia-related resistance to RT, thereby providing a framework for the design of potent radiosensitizing therapeutic approaches.

Synergistic Anticancer Therapy by Ovalbumin Encapsulation-Enabled Tandem Reactive Oxygen Species Generation

The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2.- produced by the PDT is converted to H2 O2 by superoxide dismutase, followed by the transformation of H2 O2 to the highly toxic . OH via Fenton reactions by Fe2+ originating from the dissolution of co-loaded Fe3 O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular delivery to the nucleus-even for drug-resistant cells. Cisplatin generates O2.- in the presence of nicotinamide adenine dinucleotide phosphate oxidase and thereby improves the treatment efficiency by serving as an additional O2.- source for production of . OH radicals. Improved anticancer efficiency is achieved under both hypoxic and normoxic conditions.

Illuminating Platinum Transportation while Maximizing Therapeutic Efficacy by Gold Nanoclusters via Simultaneous Near-Infrared-I/II Imaging and Glutathione Scavenging

Killing tumor cells with a visualized system is a promising strategy in tumor therapy to achieve minimal side effects and high efficiency. Herein, a theranostic nanomedicine (AuNCs-Pt) is developed based on nanocarrier gold nanoclusters (AuNCs) with bifunctions of both NIR-I/NIR-II imaging and glutathione-scavenging abilities. AuNCs-Pt possesses NIR-II imaging capability on a fatal high-grade serous ovarian cancer (HGSOC) model in the deep abdomen, thus facilitating it to be a promising tool for monitoring platinum transportation. Meanwhile, AuNCs-Pt depletes intracellular glutathione to minimize platinum detoxification, effectively maximizing the chemotherapeutic efficacy of platinum. AuNCs-Pt is used to eradicate the tumor burden in this study on a HGSOC model and a patient-derived tumor xenograft model of hepatocellular carcinoma, suggesting great potential for clinical visualized therapy and platinum drug sensitization.

Fighting against Drug-Resistant Tumors using a Dual-Responsive Pt(IV)/Ru(II) Bimetallic Polymer

Drug resistance is a major problem in cancer treatment. Herein, the design of a dual-responsive Pt(IV)/Ru(II) bimetallic polymer (PolyPt/Ru) to treat cisplatin-resistant tumors in a patient-derived xenograft (PDX) model is reported. PolyPt/Ru is an amphiphilic ABA-type triblock copolymer. The hydrophilic A blocks consist of biocompatible poly(ethylene glycol) (PEG). The hydrophobic B block contains reduction-responsive Pt(IV) and red-light-responsive Ru(II) moieties. PolyPt/Ru self-assembles into nanoparticles that are efficiently taken up by cisplatin-resistant cancer cells. Irradiation of cancer cells containing PolyPt/Ru nanoparticles with red light generates ¹ O₂ , induces polymer degradation, and triggers the release of the Ru(II) anticancer agent. Meanwhile, the anticancer drug, cisplatin, is released in the intracellular environment via reduction of the Pt(IV) moieties. The released Ru(II) anticancer agent, cisplatin, and the generated ¹ O₂ have different anticancer mechanisms; their synergistic effects inhibit the growth of drug-resistant cancer cells. Furthermore, PolyPt/Ru nanoparticles inhibit tumor growth in a PDX mouse model because they circulate in the bloodstream, accumulate at tumor sites, exhibit good biocompatibility, and do not cause side effects. The results demonstrate that the development of stimuli-responsive multi-metallic polymers provides a new strategy to overcome drug resistance.

Gold Nanoclusters as an Antibacterial Alternative Against Clostridium difficile

Background

Clostridium difficile infection (CDI) has become one of the most important factors threatening human health, and about 20-30% antibiotic-related diarrhea cases and almost all pseudomembranous enteritis cases are related to CDI. The high recurrence of Clostridium difficile (C. difficile) and the emergence of drug resistance make clinical treatment of CDI difficult. Therefore, there is an urgent need to develop a non-antibiotic-alternative therapy against CDI. Gold nanoclusters (AuNCs) can better interact with bacteria due to its ultrasmall size. The aim of the present study was to explore whether AuNCs could be used as an antibacterial agent to kill C. difficile.

Methods

AuNCs and C. difficile were co-cultivated in an anaerobic atmosphere to evaluate the bactericidal effect of AuNCs. The bacterial growth rate was estimated by using two concentrations of AuNCs (50 and 100 μM). The damage of AuNCs to C. difficile is detected by SYTOX Green staining methods and SEM image analysis. The mechanism of AuNCs on C. difficile was explored by reactive oxygen species (ROS) detection. The toxic effect of AuNCs on human cells was evaluated by MTT method.

Results

AuNCs (100 μM) killed C. difficile drastically. AuNCs increased the release of ROS by about 5 fold and destroyed the membrane integrity of C. difficile cells without causing significant toxic effect on human cells.

Conclusion

AuNCs showed great potential as an alternative to traditional antibiotics in killing C. difficile and may prove to be an alternative to treat CDI.

Use of Anticancer Platinum Compounds in Combination Therapies and Challenges in Drug Delivery

As one of the leading and most important metal-based drugs, platinum-based pharmaceuticals are widely used in the treatment of solid malignancies. Despite significant side effects and acquired drug resistance have limited their clinical applications, platinum has shown strong inhibitory effects for a wide assortment of tumors. Drug delivery systems using emerging technologies such as liposomes, dendrimers, polymers, nanotubes and other nanocompositions, all show promise for the safe delivery of platinum-based compounds. Due to the specificity of nano-formulations; unwanted side-effects and drug resistance can be largely averted. In addition, combinational therapy has been shown to be an effective way to improve the efficacy of platinum based anti-tumor drugs. This review first introduces drug delivery systems used for platinum and combinational therapeutic delivery. Then we highlight some of the recent advances in the field of drug delivery for combinational therapy; specifically progress in leveraging the cytotoxic nature of platinum-based drugs, the combinational effect of other drugs with platinum, while evaluating the drug targeting, side effect reducing and sitespecific nature of nanotechnology-based delivery platforms.

Nanomedicine in lung cancer: Current states of overcoming drug resistance and improving cancer immunotherapy

Lung cancer is considered to cause the most cancer-related deaths worldwide. Due to the deficiency in early-stage diagnostics and local invasion or distant metastasis, the first line of treatment for most patients unsuitable for surgery is chemotherapy, targeted therapy or immunotherapy. Nanocarriers with the function of improving drug solubility, in vivo stability, drug distribution in the body, and sustained and targeted delivery, can effectively improve the effect of drug treatment and reduce toxic and side effects, and have been used in clinical treatment for lung cancer and many types of cancers. Here, we review nanoparticle (NP) formulation for lung cancer treatment including liposomes, polymers, and inorganic NPs via systemic and inhaled administration, and highlight the works of overcoming drug resistance and improving cancer immunotherapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Supramolecular combination chemotherapy: a pH-responsive co-encapsulation drug delivery system

Most cancer chemotherapy regimens rely on the use of two or more chemotherapeutic agents. However, achieving the best possible dosing of the individual drugs can be challenging due to differences in metabolism, uptake, and clearance among other factors. Here we describe a supramolecular strategy for achieving drug delivery in which the loading ratio of two active components is easily defined. Specifically, we report the formation of aggregates comprised of self-assembled amphiphiles between carboxylatopillar[6]arene (CP6A) and an oxaliplatin (OX)-type Pt(iv) prodrug (PtC10). The association constant (K a) for the underlying host-guest interaction at pH 7.4 ((1.16 ± 0.03) × 104 M-1) is an order of magnitude higher than at pH 5.0 ((1.73 ± 0.15) × 103 M-1). A second chemotherapeutic, doxorubicin (DOX), may be encapsulated in the resulting vesicles (PtC10⊂CP6A) to give a supramolecular combination chemotherapeutic system DOX@PtC10⊂CP6A. Drug release studies served to confirm that PtC10 and DOX are released in acidic environments. Support for a synergistic antiproliferative effect relative to PtC10 + DOX came from cellular studies of DOX@PtC10⊂CP6A using the human liver hepatocellular carcinoma (HepG-2) cell line. In vivo studies revealed that DOX@PtC10⊂CP6A is not only able to retard tumor growth efficiently but also reduce drug-related toxic side effects in BALB/c nude mice bearing HepG-2 subcutaneous tumor xenografts. These favorable findings are attributed to the formation of a ternary complex that benefits from an enhanced permeability and retention (EPR) effect in vivo while allowing for the pH-based release of PtC10 and DOX at the tumor site.

Rational design and latest advances of codelivery systems for cancer therapy

Current treatments have limited effectiveness in treating tumors. The combination of multiple drugs or treatment strategies is widely studied to improve therapeutic effect and reduce adverse effects of cancer therapy. The codelivery system is the key to realize combined therapies. It is necessary to design and construct different codelivery systems in accordance with the variable structures and properties of cargoes and vectors. This review presented the typical design considerations about codelivery vectors for cancer therapy and described the current state of codelivery systems from two aspects: different types of vectors and collaborative treatment strategies. The commonly used loading methods of cargoes into the vectors, including physical and chemical processes, are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of codelivery systems.

Photoactivatable Prodrug-Backboned Polymeric Nanoparticles for Efficient Light-Controlled Gene Delivery and Synergistic Treatment of Platinum-Resistant Ovarian Cancer

Combination of chemotherapy and gene therapy provides an effective strategy for cancer treatment. However, the lack of suitable codelivery systems with efficient endo/lysosomal escape and controllable drug release/gene unpacking is the major bottleneck for maximizing the combinational therapeutic efficacy. In this work, we developed a photoactivatable Pt(IV) prodrug-backboned polymeric nanoparticle system (CNP_{PtCP/si(c-fos)}) for light-controlled si(c-fos) delivery and synergistic photoactivated chemotherapy (PACT) and RNA interference (RNAi) on platinum-resistant ovarian cancer (PROC). Upon blue-light irradiation (430 nm), CNP_{PtCP/si(c-fos)} generates oxygen-independent N₃^• with mild oxidation energy for efficient endo/lysosomal escape through N₃^•-assisted photochemical internalization with less gene deactivation. Thereafter, along with Pt(IV) prodrug activation, CNP_{PtCP/si(c-fos)} dissociates to release active Pt(II) and unpack si(c-fos) simultaneously. Both in vitro and in vivo results demonstrated that CNP_{PtCP/si(c-fos)} displayed excellent synergistic therapeutic efficacy on PROC with low toxicity. This PACT prodrug-backboned polymeric nanoplatform may provide a promising gene/drug codelivery tactic for treatment of various hard-to-tackle cancers.

Morphology tunable and acid-sensitive dextran-doxorubicin conjugate assemblies for targeted cancer therapy

Stimuli-responsive and targetable nanomedicine systems have been widely applied as effective modalities for drug delivery and tumor therapeutics. Particle shape is also important for the biodistribution and cellular uptake in drug delivery applications. Here, morphology tunable and acid-responsive dextran-doxorubicin conjugate assemblies of DD-M and DDF-V for targeted doxorubicin (DOX) delivery were constructed, which contain the following favorable advantages: (1) one-pot synthesis of the drug loaded system with a Schiff base reaction is a green chemistry method which is better than the conventional drug conjugation/encapsulation methods. (2) The morphology of the nanoparticles could be regulated from a micelle (DD-M) to vesicle (DDF-V) structure by either introducing folic acid (FA) or not. (3) The abundant hydroxyl groups and electronegativity give DD-M and DDF-V superior stability in the physiological environment. (4) Besides, the multifunctional DDF-V with its important merits including tumor-targeting ability and acid-responsiveness is specific for DOX delivery in cancer therapy. (5) Compared to free DOX and DD-M, DDF-V displayed enhanced anti-tumor efficacy both in vitro and in vivo without obvious systematic toxicity. The morphology tunable, acid-sensitive and targetable nanosystem could be a promising strategy for site-specific drug delivery and potential cancer therapy in the future.

A Nanostrategy for Efficient Imaging-Guided Antitumor Therapy through a Stimuli-Responsive Branched Polymeric Prodrug

A stimuli-responsive polymeric prodrug-based nanotheranostic system with imaging agents (cyanine5.5 and gadolinium-chelates) and a therapeutic agent paclitaxel (PTX) is prepared via polymerization and conjugating chemistry. The branched polymeric PTX-Gd-based nanoparticles (BP-PTX-Gd NPs) demonstrate excellent biocompatibility, and high stability under physiological conditions, but they stimuli-responsively degrade and release PTX rapidly in a tumor microenvironment. The in vitro behavior of NPs labeled with fluorescent dyes is effectively monitored, and the NPs display high cytotoxicity to 4T1 cells similar to free PTX by impairing the function of microtubules, downregulating anti-apoptotic protein Bcl-2, and upregulating the expression of Bax, cleaved caspase-3, cleaved caspase-9, cleaved-PARP, and p53 proteins. Great improvement in magnetic resonance imaging (MRI) is demonstrated by these NPs, and MRI accurately maps the temporal change profile of the tumor volume after injection of NPs and the tumor treatment process is also closely correlated with the T 1 values measured from MRI, demonstrating the capability of providing real-time feedback to the chemotherapeutic treatment effectiveness. The imaging-guided chemotherapy to the 4T1 tumor in the mice model achieves an excellent anti-tumor effect. This stimuli-responsive polymeric nano-agent opens a new door for efficient breast cancer treatment under the guidance of fluorescence/MRI.

A Metal-Polyphenol-Coordinated Nanomedicine for Synergistic Cascade Cancer Chemotherapy and Chemodynamic Therapy

The clinical application of chemotherapy is impeded by the unsatisfactory efficacy and severe side effects. Chemodynamic therapy (CDT) has emerged as an efficient strategy for cancer treatment utilizing Fenton chemistry to destroy cancer cells by converting endogenous H₂ O₂ into highly toxic reactive oxygen species. Apart from the chemotherapeutic effect, cisplatin is able to act as an artificial enzyme to produce H₂ O₂ for CDT through cascade reactions, thus remarkably improving the anti-tumor outcomes. Herein, an organic theranostic nanomedicine (PTCG NPs) is constructed with high loading capability using epigallocatechin-3-gallate (EGCG), phenolic platinum(IV) prodrug (Pt-OH), and polyphenol modified block copolymer (PEG-b-PPOH) as the building blocks. The high stability of PTCG NPs during circulation stems from their strong metal-polyphenol coordination interactions, and efficient drug release is realized after cellular internalization. The activated cisplatin elevates the intracellular H₂ O₂ level through cascade reactions. This is further utilized to produce highly toxic reactive oxygen species catalyzed by an iron-based Fenton reaction. In vitro and in vivo investigations demonstrate that the combination of chemotherapy and chemodynamic therapy achieves excellent anticancer efficacy. Meanwhile, systemic toxicity faced by platinum-based drugs is avoided through this nanoformulation. This work provides a promising strategy to develop advanced nanomedicine for cascade cancer therapy.

Thermosensitive Hydrogel Based on Poly(2-Ethyl-2-Oxazoline)-Poly(D,L-Lactide)-Poly(2-Ethyl-2-Oxazoline) for Sustained Salmon Calcitonin Delivery

This study developed a thermosensitive hydrogel based on poly(2-ethyl-2-oxazoline)-poly(D,L-lactide)-poly(2-ethyl-2-oxazoline) (PPP) for the delivery of salmon calcitonin to improve the hypocalcemic effect. The tube inversion and rheological tests revealed that the copolymer solution underwent temperature-dependent sol-gel-sol transitions. Observation by scanning electron microscopy (SEM) showed that the hydrogel exhibited a porous three-dimensional network. The swelling test demonstrated that there was a maximum swelling ratio at low temperature (25°C) as compared with the high temperature (37°C). In vitro release revealed that the PPP hydrogel were capable of sustained release of salmon calcitonin (sCT). The in vivo biodegradability study indicated the good degradability of PPP hydrogel. More importantly, the in vivo retention time of the hydrogel in situ was significantly prolonged after subcutaneous injection of the PPP hydrogel compared to the F127 hydrogel. In vivo pharmacodynamics analysis showed that the hypocalcemic effect of both PPP and F127 hydrogel was significantly greater than that of sCT solution, and the mean serum Ca reduction effect could be maintained for 24 h of PPP hydrogel, indicating that PPP hydrogel could achieve a significant enhanced hypocalcemic effect. In conclusion, the PPP hydrogel has been shown to be prospective as a controlled release carrier for injection delivery of protein drugs.

Reduction-responsive disulfide linkage core-cross-linked polymeric micelles for site-specific drug delivery

Reduction-responsive disulfide linkage core-cross-linked polymeric micelles (CLM@DOX) were developed for effective site-specific doxorubicin delivery.

Tumor extracellular pH-sensitive polymeric nanocarrier-grafted platinum(iv) prodrugs for improved intracellular delivery and cytosolic reductive-triggered release

Extracellular pH-sensitive Pt(iv)-based nanodrugs enable preferential toxicity to tumor cells via a selectively endocytosed and triggered drug release strategy.

Small-sized copolymeric nanoparticles for tumor penetration and intracellular drug release

Small-sized copolymeric nanoparticles have been developed for deep tumor penetration and nuclear drug delivery, which exhibit excellent solid tumor growth suppression.

Recent advances in metallopolymer-based drug delivery systems

Metallopolymers (MPs) or metal-containing polymers have shown great potential as new drug delivery systems (DDSs) due to their unique properties, including universal architectures, composition, properties and surface chemistry. Over the past few decades, the exponential growth of many new classes of MPs that deal with these issues has been demonstrated. This review presents and assesses the recent advances and challenges associated with using MPs as DDSs. Among the most widely used MPs for these purposes, metal complexes based on synthetic and natural polymers, coordination polymers, metal-organic frameworks, and metallodendrimers are distinguished. Particular attention is paid to the stimulus- and multistimuli-responsive metallopolymer-based DDSs. Of considerable interest is the use of MPs for combination therapy and multimodal systems. Finally, the problems and future prospects of using metallopolymer-based DDSs are outlined. The bibliography includes articles published over the past five years.

Recent Trends of the Bio-Inspired Nanoparticles in Cancer Theranostics

In recent years, various nanomaterials have emerged as an exciting tool in cancer theranostic applications due to their multifunctional property and intrinsic molecular property aiding effective diagnosis, imaging, and successful therapy. However, chemically synthesized nanoparticles have several issues related to the cost, toxicity and effectiveness. In this context, bio-inspired nanoparticles (NPs) held edges over conventionally synthesized nanoparticles due to their low cost, easy synthesis and low toxicity. In this present review article, a detailed overview of the cancer theranostics applications of various bio-inspired has been provided. This includes the recent examples of liposomes, lipid nanoparticles, protein nanoparticles, inorganic nanoparticles, and viral nanoparticles. Finally, challenges and the future scopes of these NPs in cancer therapy and diagnostics applications are highlighted.

Cyclic RGD-Functionalized and Disulfide-Crosslinked Iodine-Rich Polymersomes as a Robust and Smart Theranostic Agent for Targeted CT Imaging and Chemotherapy of Tumor

There is tremendous interest in integrating CT imaging with chemotherapy; however, reported iodine-based nanosystems such as nanogels and nano-emulsions display typically reduced contrast coefficient, low drug loading and stability, and poor targetability. Here, cRGD-functionalized disulfide-crosslinked iodine-rich polymersomes (cRGD-XIPs) were designed as a novel, robust and smart theranostic agent and investigated for targeted CT imaging and chemotherapy of malignant tumors. Methods: cRGD-XIPs were prepared from co-self-assembly of poly(ethylene glycol)-b-poly(dithiolane trimethylene carbonate-co-iodinated trimethylene carbonate) (PEG-P(DTC-IC)) and cRGD-PEG-P(DTC-IC) block copolymers. In vitro and in vivo CT contrast effect of cRGD-XIPs was studied using α_vβ₃-overexpressing B16 melanoma as a tumor model in comparison with clinical agent iohexol. The therapeutic efficacy of doxorubicin-loaded cRGD-XIPs (cRGD-XIPs-Dox) to B16 melanoma was investigated and compared with XIPs-Dox (non-targeted), cRGD-IPs-Dox (non-crosslinked) and free Dox. Results: cRGD-XIPs were formed with 55.5 wt.% iodine and ca. 90 nm in diameter. cRGD-XIPs-Dox with a Dox loading of 15.3 wt.% bared superior colloidal stability and reduction-responsive drug release. Notably, blank cRGD-XIPs showed a maximum-tolerated dose (MTD) > 400 mg iodine equiv./kg while cRGD-XIPs-Dox had an MTD > 150 mg Dox equiv./kg, ca. 15-fold improvement over free Dox. cRGD-XIPs revealed superior CT contrast effect and achieved 46.5- and 24.0-fold better enhancement of CT imaging of B16 melanoma than iohexol at 4 h following intratumoral and intravenous injection, respectively. cRGD-XIPs-Dox displayed an elimination half-life of 6.5 h and an elevated accumulation of 6.68% ID/g in the tumors. Furthermore, cRGD-XIPs-Dox was significantly more effective than XIPs-Dox and cRGD-XPs-Dox in inhibiting growth of B16 melanoma model. Conclusion: This proof-of-concept study demonstrates that cRGD-XIPs are a robust, non-toxic and smart polymeric theranostic agent that can not only significantly enhance CT imaging of tumors but also mediate efficient tumor-targeted chemotherapy. XIPs offer a unique and safe platform for theranostic polymersomes that pre-select patients using CT imaging prior to targeted chemotherapy with the same system.

Block copolymer prodrugs: Synthesis, self-assembly, and applications for cancer therapy

Block copolymer prodrugs (BCPs) have emerged as one of the most promising anticancer drug delivery strategies, which can self-assemble into nanoparticles with optimal physicochemical properties including sizes, morphologies, surface properties, and integration of multifunction for improved in vivo applications. Moreover, the utility of stimuli-responsive linkages to conjugate drugs onto the polymer backbones can achieve efficient and targeting drug release. Several BCP micellar delivery systems have been pushed ahead into the clinical trials, which showed great promising potentials for cancer therapy. In recent years, various novel and more efficient BCP systems have been developed for better in vivo performance. In this focus article, we focus on the recent advances of BCPs including the synthesis, self-assembly, and applications for cancer therapy. The synthetic methods are first introduced, and the self-assembly of BCPs for in vivo anticancer applications is discussed along the line of varying endogenous stimuli-responsive linkages including amide or ester bonds, pH, reduction, and oxidation-responsive linkages. Finally, conclusions along with the brief future perspectives are presented. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.