Enhanced cytotoxicity to cancer cells by mitochondria-targeting MWCNTs containing platinum(IV) prodrug of cisplatin

Carboxymethyl chitosan-modified folate-targeted carbon nanotube-baicalin complexes for cancer progression and metastasis

Achieving desirable clinical outcomes is difficult given the rising number of cases and mortality of oral squamous cell carcinoma. Consequently, developing an efficient drug delivery system for managing cancer progression and metastasis with relatively low toxicity has proven to be highly promising. Initially, carboxymethyl chitosan was covalently modified and partially substituted with folic acid, and subsequently encapsulated as a shell to deliver carboxylated multiwalled carbon nanotube and their coupled baicalin to form carboxymethyl chitosan-modified folate-targeted carbon nanotube-baicalein complexes. The impact on the normal cell line HOK and the oral squamous cell carcinoma cell line CAL27 was assessed using CCK8, live-dead cell assay, colony formation assay, flow cytometry, wound healing assay, and transwell migration and invasion assays. These analyses confirmed that the complexes induced apoptosis in cancer cells and reduced the migration and invasion of CAL27 cells. Additionally, the complexes demonstrated enhanced biosafety, significantly inhibited the growth of xenograft tumors and tissue metastasis, and altered the expression of proteins associated with epithelial-mesenchymal transition. The results mentioned above imply that the complexes may offer novel applications and serve as an effective strategy for preventing cancer spread and metastasis.

Engineering biotin anchored-MWCNTs as a superb carrier for facile delivery of the potent Ru(II)-N^N scaffold in breast cancer cells

Ru(II)-complexes have been recognised as promising in treating cancer. However, targeted delivery is an important facet to augment the efficiency of drugs. Consequently, this article portrays the construction of biotinylated-MWCNTs as an SMVT-guided nano-platform for the precise delivery of our previously-developed potent Ru(II)-scaffold, making it more effective against MCF-7 cells.

Exploring the therapeutic applications of nano-therapy of encapsulated cisplatin and anthocyanin-loaded multiwalled carbon nanotubes coated with chitosan-conjugated folic acid in targeting breast and liver cancers

This study aimed to assess the targeted nano-therapy of encapsulated cisplatin (Cis) and anthocyanin (Ant)-loaded multiwalled carbon nanotubes (CNT) coated with chitosan conjugated folic acid on breast MCF7 and liver HepG2 cancer cells. Zeta potential, UV-spectroscopy, FTIR, TEM, and SEM were used to evaluate CNT, its modified form (CNT Mod), CNT-loaded Cis NPs, CNT-loaded Ant NPs, and CNT- Cis + Ant NPs. All treatments induced apoptosis-dependent cytotoxicity in both cell lines as revealed functionally by the MTT assay, morphologically (DNA degradation) by acridine orange/ethidium bromide (AO/EB) double staining, and molecularly (Bax upregulation and Bcl2 downregulation) by real-time PCR, with best effect for the combined treatment (CNT- Cis + Ant NPs). This combined treatment also significantly reduced inflammation (low TNFα), migration (low MMP9 and high TIMP1), and angiogenesis (low VEGF), while significantly increasing antioxidant status (high Nrf2 and OH-1) in MCF7 and HepG2 cells compared to other treatments. Interestingly, cells treated with CNT Mod exhibited higher cytotoxic, apoptotic, anti-migratory, and anti-angiogenic potentials relative to CNT-treated cells. In conclusion, targeted nano-therapy of encapsulated cisplatin and anthocyanin-loaded carbon nanotubes coated with chitosan conjugated folic acid can efficiently combat breast and liver cancers by sustained release, in addition to its apoptotic, antioxidant, anti-inflammatory, anti-metastatic, and anti-angiogenic effects.

Engineering carbon-based nanomaterials for the delivery of platinum compounds: An innovative cancer disarming frontier

Carbon-based nanomaterials have been frequently used as one of the most advanced and fascinating nanocarriers for drug delivery applications due to their unique physicochemical properties. Varying types of carbon nanomaterials (CNMs) including carbon nanotubes, graphene, graphene oxides, carbon nanohorns, fullerenes, carbon nanodots, and carbon nanodiamonds are promising candidates for designing novel systems to deliver platinum compounds. CNMs modification with various moieties renders vast bio-applications in the area of targeted and organelle-specific cancer therapy. This review featured an updated and concise summarizations of various types of CNMs, their synthesis, advantages and disadvantages including potential bio-toxicity for biomedical applications. The therapeutic utility of CNMs and their efficacy have been noticed and for the first time, this review addressed CNMs-focused applications on the delivery of platinum-derivatives to the cancer site. Collectively, the contents of this review will assist researchers to focus on the possible fabrication, bio-functionalization and designing methods of CNMs to the further development of their future biomedical implementations.

Strategic disruption of cancer's powerhouse: precise nanomedicine targeting of mitochondrial metabolism

Mitochondria occupy a central role in the biology of most eukaryotic cells, functioning as the hub of oxidative metabolism where sugars, fats, and amino acids are ultimately oxidized to release energy. This crucial function fuels a variety of cellular activities. Disruption in mitochondrial metabolism is a common feature in many diseases, including cancer, neurodegenerative conditions and cardiovascular diseases. Targeting tumor cell mitochondrial metabolism with multifunctional nanosystems emerges as a promising strategy for enhancing therapeutic efficacy against cancer. This review comprehensively outlines the pathways of mitochondrial metabolism, emphasizing their critical roles in cellular energy production and metabolic regulation. The associations between aberrant mitochondrial metabolism and the initiation and progression of cancer are highlighted, illustrating how these metabolic disruptions contribute to oncogenesis and tumor sustainability. More importantly, innovative strategies employing nanomedicines to precisely target mitochondrial metabolic pathways in cancer therapy are fully explored. Furthermore, key challenges and future directions in this field are identified and discussed. Collectively, this review provides a comprehensive understanding of the current state and future potential of nanomedicine in targeting mitochondrial metabolism, offering insights for developing more effective cancer therapies.

Functionalized Carbon Nanotubes for Delivery of Ferulic Acid and Diosgenin Anticancer Natural Agents

It was investigated whether loading multi-wall carbon nanotubes (CNTs) with two natural anticancer agents: ferulic acid (FUA) and diosgenin (DGN), may enhance the anticancer effect of these drugs. The CNTs were functionalized with carboxylic acid (CNTCOOH) or amine (CNTNH2), loaded with the above pro-drugs, as well as both combined and coated with chitosan or chitosan-stearic acid. Following physicochemical characterization, the drug-loading properties and kinetics of the drug's release were investigated. Their effects on normal human skin fibroblasts and MCF-7 breast carcinoma cells, HepG2 hepatocellular carcinoma cells, and A549 non-small-cell lung cancer cells were evaluated in vitro. Their actions at the molecular level were evaluated by assessing the expression of lncRNAs (HULC, HOTAIR, CCAT-2, H19, and HOTTIP), microRNAs (mir-21, mir-92, mir-145, and mir-181a), and proteins (TGF-β and E-cadherin) in HepG2 cells. The release of both pro-drugs depended on the glutathione concentration, coating, and functionalization. Release occurred in two stages: a no-burst/zero-order release followed by a sustained release best fitted to Korsmeyer-Peppas kinetics. The combined nanoformulation cancer inhibition effect on HepG2 cancer cells was more pronounced than for A549 and MCF7 cells. The combined nanoformulations had an additive impact followed by a synergistic effect, with antagonism demonstrated at high concentrations. The nanoformulation coated with chitosan and stearic acid was particularly successful in targeting HepG2 cells and inducing apoptosis. The CNT functionalized with carboxylic acid (CNTCOOH), loaded with both FUA and DGN, and coated with chitosan-stearic acid inhibited the expression of lncRNAs and modulated both microRNAs and proteins. Thus, nanoformulations composed of functionalized CNTs dual-loaded with FUA and DGN and coated with chitosan-stearic acid are a promising drug delivery system that enhances the activity of natural pro-drugs.

The Promoting Role of HK II in Tumor Development and the Research Progress of Its Inhibitors

Increased glycolysis is a key characteristic of malignant cells that contributes to their high proliferation rates and ability to develop drug resistance. The glycolysis rate-limiting enzyme hexokinase II (HK II) is overexpressed in most tumor cells and significantly affects tumor development. This paper examines the structure of HK II and the specific biological factors that influence its role in tumor development, as well as the potential of HK II inhibitors in antitumor therapy. Furthermore, we identify and discuss the inhibitors of HK II that have been reported in the literature.

Application of Nanoparticles in Cancer Treatment: A Concise Review

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010-2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics.

Functional Materials for Subcellular Targeting Strategies in Cancer Therapy: Progress and Prospects

Neoadjuvant and adjuvant therapies have made significant progress in cancer treatment. However, tumor adjuvant therapy still faces challenges due to the intrinsic heterogeneity of cancer, genomic instability, and the formation of an immunosuppressive tumor microenvironment. Functional materials possess unique biological properties such as long circulation times, tumor-specific targeting, and immunomodulation. The combination of functional materials with natural substances and nanotechnology has led to the development of smart biomaterials with multiple functions, high biocompatibilities, and negligible immunogenicities, which can be used for precise cancer treatment. Recently, subcellular structure-targeting functional materials have received particular attention in various biomedical applications including the diagnosis, sensing, and imaging of tumors and drug delivery. Subcellular organelle-targeting materials can precisely accumulate therapeutic agents in organelles, considerably reduce the threshold dosages of therapeutic agents, and minimize drug-related side effects. This review provides a systematic and comprehensive overview of the research progress in subcellular organelle-targeted cancer therapy based on functional nanomaterials. Moreover, it explains the challenges and prospects of subcellular organelle-targeting functional materials in precision oncology. The review will serve as an excellent cutting-edge guide for researchers in the field of subcellular organelle-targeted cancer therapy.

Gelatin-Functionalized Carbon Nanotubes Loaded with Cisplatin for Anti-Cancer Therapy

Cisplatin (Cp), a chemotherapeutic agent, interacts with purines on tumor DNA, causing tumor cell apoptosis. However, cisplatin has the characteristics of non-specific distribution and lack of selectivity, resulting in systemic toxicity. Moreover, it cannot maintain the drug's high concentration in the tumor-weak acid environment. These flaws of cisplatin restrict its use in clinical applications. Therefore, a pH-responsive carbon nanotube-modified nano-drug delivery system (CNTs/Gel/Cp) was constructed in this study using gelatin (Gel)-modified carbon nanotubes (CNTs/Gel) loaded with cisplatin to release drugs precisely and slowly, preventing premature inactivation and maintaining an effective concentration. When MCp:MCNTs/Gel = 1:1, the drug reaches the highest loading rate and entrapment efficiency. To achieve the sustained-release effect, CNTs/Gel/Cp can release the medicine steadily for a long time in a pH environment of 6.0. Additionally, CNTs/Gel/Cp display antitumor properties comparable to cisplatin in a manner that varies with the dosage administered. These findings indicate that CNTs/Gel/Cp have an effective, sustained release of cisplatin and a good antitumor effect, providing a theoretical and experimental basis for the clinical application of modified carbon nanotubes (CNTs) as a new drug delivery system.

Mitochondrial-targeted nanoparticles: Delivery and therapeutic agents in cancer

Mitochondria are the powerhouses of cells and modulate the essential metabolic functions required for cellular survival. Various mitochondrial pathways, such as oxidative phosphorylation or production of reactive oxygen species (ROS) are dysregulated during cancer growth and development, rendering them attractive targets against cancer. Thus, the delivery of antitumor agents to mitochondria has emerged as a potential approach for treating cancer. Recent advances in nanotechnology have provided innovative solutions for overcoming the physical barriers posed by the structure of mitochondrial organelles, and have enabled the development of efficient mitochondrial nanoplatforms. In this review, we examine the importance of mitochondria during neoplastic development, explore the most recent smart designs of nano-based systems aimed at targeting mitochondria, and highlight key mitochondrial pathways in cancer cells.

Porous Silicon Nanocarriers Boost the Immunomodulation of Mitochondria-Targeted Bovine Serum Albumins on Macrophage Polarization

The development of nanosystems with intrinsic immunomodulatory effects on macrophage polarization is important for the macrophage-targeted immunotherapy. Here, mitochondria-targeted bovine serum albumins (BSAs) via the conjugation of fluorescent, lipophilic, and cationic rhodamine 110 molecules can efficiently enhance the gene expression of the proinflammatory phenotype of macrophages and correspondingly inhibit the gene expression of their anti-inflammatory phenotype. On this basis, porous silicon nanocarriers can further boost the immunomodulation of these mitochondria-targeted BSAs in vitro or in vivo, accompanied by the secretion of proinflammatory mediators including tumor necrosis factor α, nitric oxide, and reactive oxygen species (ROS). Meanwhile, BSA coatings can also improve the biocompatibility of porous silicon nanoparticulate cores on macrophages. Finally, the mechanism investigations demonstrate that porous silicon nanocarriers can efficiently deliver mitochondria-targeted BSA into macrophages to generate mitochondrial ROS via the interference with mitochondrial respiratory chains, which can further trigger the downstream signaling transduction pathways for the proinflammatory transition. Considering the good biosafety and versatile loading capability, this developed porous silicon@BSA nanosystem with a strong proinflmmatory regulatory effect has important potential on the combinatorial chemoimmunotherapy against cancer or viral/bacterial-related infectious diseases.

Delivering the Promise of Gene Therapy with Nanomedicines in Treating Central Nervous System Diseases

Central Nervous System (CNS) diseases, such as Alzheimer's diseases (AD), Parkinson's Diseases (PD), brain tumors, Huntington's disease (HD), and stroke, still remain difficult to treat by the conventional molecular drugs. In recent years, various gene therapies have come into the spotlight as versatile therapeutics providing the potential to prevent and treat these diseases. Despite the significant progress that has undoubtedly been achieved in terms of the design and modification of genetic modulators with desired potency and minimized unwanted immune responses, the efficient and safe in vivo delivery of gene therapies still poses major translational challenges. Various non-viral nanomedicines have been recently explored to circumvent this limitation. In this review, an overview of gene therapies for CNS diseases is provided and describes recent advances in the development of nanomedicines, including their unique characteristics, chemical modifications, bioconjugations, and the specific applications that those nanomedicines are harnessed to deliver gene therapies.

Dendritic Polyglycerol-Conjugated Gold Nanostars for Metabolism Inhibition and Targeted Photothermal Therapy in Breast Cancer Stem Cells

Breast cancer stem cells (CSCs) are believed to be responsible for tumor initiation, invasion, metastasis, and recurrence, which lead to treatment failure. Thus, developing effective CSC-targeted therapeutic strategies is crucial for enhancing therapeutic efficacy. In this work, GNSs-dPG-3BP, TPP, and HA nanocomposite particles are developed by simultaneously conjugating hexokinase 2 (HK2) inhibitor 3-bromopyruvate (3BP), mitochondrial targeting molecule triphenyl phosphonium (TPP), and CSCs targeting agent hyaluronic acid (HA) onto gold nanostars-dendritic polyglycerol (GNSs-dPG) nanoplatforms for efficient eradication of CSCs. The nanocomposite particles possess good biocompatibility and exhibit superior mitochondrial-bound HK2 binding ability via 3BP to inhibit metabolism, and further induce cellular apoptosis by releasing the cytochrome c. Therefore, it enhanced the therapeutic efficacy of CSCs-specific targeted photothermal therapy (PTT), and achieved a synergistic effect for the eradication of breast CSCs. After administration of the synergistic treatment, the self-renewal of breast CSCs and the stemness gene expression are suppressed, CSC-driven mammosphere formation is diminished, the in vivo tumor growth is effectively inhibited, and CSCs are eradicated. Altogether, GNSs-dPG-3BP, TPP, and HA nanocomposite particles have been developed, which will provide a novel strategy for precise and highly efficient targeted eradication of CSCs.

Chimeric nanoparticles for targeting mitochondria in cancer cells

Mitochondrial dysfunction is implicated in myriad diseases, including cancer. Subsequently, targeting mitochondrial DNA (mt-DNA) in cancer cells has emerged as an unorthodox strategy for anti-cancer therapy. However, approaches targeting only one component of the mitochondrial "central dogma" can be evaded by cancer cells through various mechanisms. To address this, herein, we have engineered mitochondria-targeting cholesterol-based chimeric nanoparticles (mt-CNPs) consisting of cisplatin, camptothecin, and tigecycline, which can simultaneously impair mt-DNA, mitochondrial topoisomerase I (mt-Top1), and mitochondrial ribosomes. mt-CNPs were characterized as being positively charged, spherical in shape, and 187 nm in diameter. Confocal microscopy confirmed that mt-CNPs efficiently localized into the mitochondria of A549 lung cancer cells within 6 h, followed by mitochondrial morphology damage and the subsequent generation of reactive oxygen species (ROS). mt-CNPs showed remarkable cancer-cell killing abilities compared to free-drug combinations in A549 (lung), HeLa (cervical), and MCF7 (breast) cancer cells. These mitochondria-targeting lipidic chimeric nanoparticles could be explored further to impair multiple targets in mitochondria, helping researchers to gain an understanding of mitochondrial translational and transcriptional machinery and to develop new strategies for cancer therapy.

Insights on functionalized carbon nanotubes for cancer theranostics

Despite the exciting breakthroughs in medical technology, cancer still accounts for one of the principle triggers of death and conventional therapeutic modalities often fail to attain an effective cure. Recently, nanobiotechnology has made huge advancement in cancer therapy with gigantic application potential because of their ability in achieving precise and controlled drug release, elevating drug solubility and reducing adverse effects. Carbon nanotubes (CNTs), one of the most promising carbon-related nanomaterials, have already achieved much success in biomedical field. Due to their excellent optical property, thermal and electronic conductivity, easy functionalization ability and high drug loading capacity, CNTs can be applied in a multifunctional way for cancer treatment and diagnosis. In this review, we will give an overview of the recent progress of CNT-based drug delivery systems in cancer theranostics, which emphasizes their targetability to intracellular components of tumor cells and extracellular elements in tumor microenvironment. Moreover, a detailed introduction on how CNTs penetrate inside the tumor cells to reach their sites of action and achieve the therapeutic effects, as well as their diagnostic applications will be highlighted.

Visible Light and Glutathione Dually Responsive Delivery of a Polymer-Conjugated Temozolomide Intermediate for Glioblastoma Chemotherapy

Temozolomide (TMZ) is a prodrug of 5-(3-methyltriazene-1-yl)imidazole-4-carboxamide (MTIC, short-lived) and used as a first-line therapy drug for glioblastoma multiforme (GBM). However, little progress has been made in regulating the kinetics of TMZ to MTIC degradation to improve the therapeutic effect, particularly in the case of TMZ-resistant GBM. In this work, we introduced a strategy to cage MTIC by N-acylation of the triazene moiety to boost the MTIC stability, designed a diblock copolymer-based MTIC prodrug installed with a disulfide linkage, and achieved self-assembled polymer micelles without the concern of MTIC leakage under physiological conditions. Polymer micelles could be induced to disassemble by stimuli factors such as glutathione (GSH) and visible light irradiation through thiol/sulfide exchange and homolytic sulfide scission mechanisms, which contributed to MTIC release in GSH-dependent and GSH-independent pathways. The in vitro results demonstrated that microenvironment-responsive polymeric micelles benefited the suppression of both TMZ-sensitive and TMZ-resistant GBM cells. The chemistry of polymer-MTIC prodrug provided a new option for TMZ-based glioma treatment.

Mitochondria-Targeted Nanomedicine for Enhanced Efficacy of Cancer Therapy

Nanomedicines have been designed and developed to deliver anticancer drugs or exert anticancer therapy more selectively to tumor sites. Recent investigations have gone beyond delivering drugs to tumor tissues or cells, but to intracellular compartments for amplifying therapy efficacy. Mitochondria are attractive targets for cancer treatment due to their important functions for cells and close relationships to tumor occurrence and metastasis. Accordingly, multifunctional nanoplatforms have been constructed for cancer therapy with the modification of a variety of mitochondriotropic ligands, to trigger the mitochondria-mediated apoptosis of tumor cells. On this basis, various cancer therapeutic modalities based on mitochondria-targeted nanomedicines are developed by strategies of damaging mitochondria DNA (mtDNA), increasing reactive oxygen species (ROS), disturbing respiratory chain and redox balance. Herein, in this review, we highlight mitochondria-targeted cancer therapies enabled by nanoplatforms including chemotherapy, photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), radiodynamic therapy (RDT) and combined immunotherapy, and discussed the ongoing challenges.

Novel Strategies for Disrupting Cancer-Cell Functions with Mitochondria-Targeted Antitumor Drug-Loaded Nanoformulations

Any variation in normal cellular function results in mitochondrial dysregulation that occurs in several diseases, including cancer. Such processes as oxidative stress, metabolism, signaling, and biogenesis play significant roles in cancer initiation and progression. Due to their central role in cellular metabolism, mitochondria are favorable therapeutic targets for the prevention and treatment of conditions like neurodegenerative diseases, diabetes, and cancer. Subcellular mitochondria-specific theranostic nanoformulations for simultaneous targeting, drug delivery, and imaging of these organelles are of immense interest in cancer therapy. It is a challenging task to cross multiple barriers to target mitochondria in diseased cells. To overcome these multiple barriers, several mitochondriotropic nanoformulations have been engineered for the transportation of mitochondria-specific drugs. These nanoformulations include liposomes, dendrimers, carbon nanotubes, polymeric nanoparticles (NPs), and inorganic NPs. These nanoformulations are made mitochondriotropic by conjugating them with moieties like dequalinium, Mito-Porter, triphenylphosphonium, and Mitochondria-penetrating peptides. Most of these nanoformulations are meticulously tailored to control their size, charge, shape, mitochondriotropic drug loading, and specific cell-membrane interactions. Recently, some novel mitochondria-selective antitumor compounds known as mitocans have shown high toxicity against cancer cells. These selective compounds form vicious oxidative stress and reactive oxygen species cycles within cancer cells and ultimately push them to cell death. Nanoformulations approved by the FDA and EMA for clinical applications in cancer patients include Doxil, NK105, and Abraxane. The novel use of these NPs still faces tremendous challenges and an immense amount of research is needed to understand the proper mechanisms of cancer progression and control by these NPs. Here in this review, we summarize current advancements and novel strategies of delivering different anticancer therapeutic agents to mitochondria with the help of various nanoformulations.

Postoperative cancer treatments: In-situ delivery system designed on demand

The keys to the prevention of tumor recurrence after operation are the elimination of residual tumor cells and the reversal of microenvironments that induce recurrence. In the formulation of a treatment scheme, building an appropriate drug delivery system is essential. An in-situ drug delivery system (ISDDS) is regarded as an effective treatment route for postoperative use that increases drug delivery efficiency and mitigates side-effects. ISDDS technology has been considerably improved through a clearer understanding of the mechanisms of postoperative recurrence and the development of drug delivery materials. This paper describes the initiation and characteristics of postoperative recurrence mechanisms. Based on this information, design principles for ISDDS are proposed, and a variety of practical drug delivery systems that fulfil specific therapeutic needs are presented. Challenges and future opportunities related to the application of in-situ drug carriers for inhibiting cancer recurrence are also discussed.

Precisely Assembled Nanoparticles against Cisplatin Resistance via Cancer-Specific Targeting of Mitochondria and Imaging-Guided Chemo-Photothermal Therapy

Cisplatin resistance in tumor cells is known mainly due to the reduced accumulation of platinum ions by efflux, detoxification by intracellular GSH, and nucleotide excision repair machinery-mediated nuclear DNA repair. In this work, theranostic Pt(IV)-NPs, which are precisely self-assembled by biotin-labeled Pt(IV) prodrug derivative and cyclodextrin-functionalized IR780 in a 1:1 molecular ratio, have been developed for addressing all these hurdles via mitochondria-targeted chemotherapy solely or chemophotothermal therapy. In these nanoparticles, IR780 as a small-molecule dye acts as a mitochondria-targeting ligand to make Pt(IV)-NPs relocate finally in the mitochondria and release cisplatin. As demonstrated by in vitro and in vivo experiments, Pt(IV)-NPs can markedly facilitate cancer-specific mitochondrial targeting, inducing mitochondrial dysfunction and mitochondrial DNA (mtDNA) damage, thus greatly increasing the Pt accumulation, reducing the GSH levels, and avoiding DNA repair machinery in cisplatin-resistant cancer cells (A549R), finally resulting in significant inhibition of A549R tumor growth on animal models by chemotherapy solely. Upon near-infrared irradiation, mitochondria-targeted chemophotothermal synergistic therapy can be realized, further overcoming cisplatin resistance and even eliminating A549R tumors completely. Moreover, such novel Pt(IV)-NPs integrate multimodal targeting (cancer and mitochondria targeting), imaging (near-infrared imaging and photoacoustic imaging), and therapeutic (chemo- and photothermal therapy) moieties in a constant ratio (1:1:1) into a single, reproducible, and structurally homogeneous entity, avoiding nonuniform drug loading and premature leakage as well as the discrete steps of imaging and therapy, which thus is more beneficial for precise therapeutics and future clinical translation.

Smart Design of Nanomaterials for Mitochondria-Targeted Nanotherapeutics

Mitochondria are the powerhouse of cells. They are vital organelles that maintain cellular function and metabolism. Dysfunction of mitochondria results in various diseases with a great diversity of clinical appearances. In the past, strategies have been developed for fabricating subcellular-targeting drug-delivery nanocarriers, enabling cellular internalization and subsequent organelle localization. Of late, innovative strategies have emerged for the smart design of multifunctional nanocarriers. Hierarchical targeting enables nanocarriers to evade and overcome various barriers encountered upon in vivo administration to reach the organelle with good bioavailability. Stimuli-responsive nanocarriers allow controlled release of therapeutics to occur at the desired target site. Synergistic therapy can be achieved using a combination of approaches such as chemotherapy, gene and phototherapy. In this Review, we survey the field for recent developments and strategies used in the smart design of nanocarriers for mitochondria-targeted therapeutics. Existing challenges and unexplored therapeutic opportunities are also highlighted and discussed to inspire the next generation of mitochondrial-targeting nanotherapeutics.

Peptide Fibrillar Assemblies Exhibit Membranolytic Effects and Antimetastatic Activity on Lung Cancer Cells

Cancer metastasis is a central oncology concern that worsens patient conditions and increases mortality in a short period of time. During metastatic events, mitochondria undergo specific physiological alterations that have emerged as notable therapeutic targets to counter cancer progression. In this study, we use drug-free, cationic peptide fibrillar assemblies (PFAs) formed by poly(L-Lysine)-block-poly(L-Threonine) (Lys-b-Thr) to target mitochondria. These PFAs interact with cellular and mitochondrial membranes via electrostatic interactions, resulting in membranolysis. Charge repulsion and hydrogen-bonding interactions exerted by Lys and Thr segments dictate the packing of the peptides and enable the PFAs to display enhanced membranolytic activity toward cancer cells. Cytochrome c (cyt c), endonuclease G, and apoptosis-inducing factor were released from mitochondria after treatment of lung cancer cells, subsequently inducing caspase-dependent and caspase-independent apoptotic pathways. A metastatic xenograft mouse model was used to show how the PFAs significantly suppressed lung metastasis and inhibited tumor growth, while avoiding significant body weight loss and mortality. Antimetastatic activities of PFAs are also demonstrated by in vitro inhibition of lung cancer cell migration and clonogenesis. Our results imply that the cationic PFAs achieved the intended and targeted mitochondrial damage, providing an efficient antimetastatic therapy.

Targeting drug delivery system for platinum(Ⅳ)-Based antitumor complexes

Classical platinum(II) anticancer agents are widely-used chemotherapeutic drugs in the clinic against a range of cancers. However, severe systemic toxicity and drug resistance have become the main obstacles which limit their application and effectiveness. Because divalent cisplatin analogues are easily destroyed in vivo, their bioavailability is low and no selective to tumor tissues. The platinum(IV) prodrugs are attractive compounds for cancer treatment because they have great advantages, e.g., higher stability in biological media, aqueous solubility and no cross-resistance with cisplatin, which may become the next generation of platinum anticancer drugs. In addition, platinum(IV) drugs could be taken orally, which could be more acceptable to cancer patients, breaking the current situation that platinum(II) drugs can only be given by injection. The coupling of platinum(IV) complexes with tumor targeting groups avoids the disadvantages such as instability in blood, irreversible binding to plasma proteins, rapid renal clearance, and non-specific distribution in normal tissues. Because of the above advantages, the combination of platinum complexes and tumor targeting groups has become the hottest field in the research and development of new platinum drugs. These approaches can be roughly categorized into two groups: active and passive targeted strategies. This review concentrates on various targeting and delivery strategies for platinum(IV) complexes to improve the efficacy and reduce the side effects of platinum-based anticancer drugs. We have made a summary of the related articles on platinum(IV) targeted delivery in recent years. We believe the results of the studies described in this review will provide new ideas and strategies for the development of platinum drugs.

Tumor- and mitochondria-targeted nanoparticles eradicate drug resistant lung cancer through mitochondrial pathway of apoptosis

Chemotherapeutic drugs frequently encounter multidrug resistance. ATP from mitochondria helps overexpression of drug efflux pumps to induce multidrug resistance, so mitochondrial delivery as a means of "repurposing'' chemotherapeutic drugs currently used in the clinic appears to be a worthwhile strategy to pursue for the development of new anti-drug-resistant cancer agents. TPP-Pluronic F127-hyaluronic acid (HA) (TPH), with a mitochondria-targeting triphenylphosphine (TPP) head group, was first synthesized through ester bond formation. Paclitaxel (PTX)-loaded TPH (TPH/PTX) nanomicelles exhibited excellent physical properties and significantly inhibited A549/ADR cells. After TPH/PTX nanomicelles entered acidic lysosomes through macropinocytosis, the positively charged TP/PTX nanomicelles that resulted from degradation of HA by hyaluronidase (HAase) in acidic lysosomes were exposed and completed lysosomal escape at 12 h, finally localizing to mitochondria over a period of 24 h in A549/ADR cells. Subsequently, TPH/PTX caused mitochondrial outer membrane permeabilization (MOMP) by inhibiting antiapoptotic Bcl-2, leading to cytochrome C release and activation of caspase-3 and caspase-9. In an A549/ADR xenograft tumor model and a drug-resistant breast cancer-bearing mouse model with lung metastasis, TPH/PTX nanomicelles exhibited obvious tumor targeting and significant antitumor efficacy. This work presents the potential of a single, nontoxic nanoparticle (NP) platform for mitochondria-targeted delivery of therapeutics for diverse drug-resistant cancers.

Hyaluronate Functionalized Multi-Wall Carbon Nanotubes Filled with Carboplatin as a Novel Drug Nanocarrier against Murine Lung Cancer Cells

Carbon nanotubes (CNTs) have emerged in recent years as a potential option for drug delivery, due to their high functionalization capacity. Biocompatibility and selectivity using tissue-specific biomolecules can optimize the specificity, pharmacokinetics and stability of the drug. In this study, we design, develop and characterize a drug nanovector (oxCNTs-HA-CPT) conjugating oxidated multi-wall carbon nanotubes (oxCNTs) with hyaluronate (HA) and carboplatin (CPT) as a treatment in a lung cancer model in vitro. Subsequently, we exposed TC-1 and NIH/3T3 cell lines to the nanovectors and measured cell uptake, cell viability, and oxidative stress induction. The characterization of oxCNTs-HA-CPT reveals that on their surface, they have HA. On the other hand, oxCNTs-HA-CPT were endocytosed in greater proportion by tumor cells than by fibroblasts, and likewise, the cytotoxic effect was significantly higher in tumor cells. These results show the therapeutic potential that nanovectors possess; however, future studies should be carried out to determine the death pathways involved, as well as their effect on in vivo models.

Design and investigation of photoactivatable platinum(iv) prodrug complexes of cisplatin

Platinum(iv) carboxylate scaffolds have garnered considerable research interest because they can be engineered to function as prodrugs of clinical platinum(ii) anticancer drugs. These platinum(iv) prodrug complexes are stable and tunable, and activated by reduction to release their cytotoxic platinum(ii) cargo. Here we propose new platinum(iv) prodrug complexes designed to release cisplatin via photoreduction upon UV irradiation. The central strategy is to utilise aryl carboxylate ligands on the axial positions of that platinum(iv) scaffold that confer significant UV absorption and would stabilise carboxyl radical formation, thus favouring homolytic Pt-O bond cleavage. We isolated and identified aryl carboxyl radicals via spin-trapping and showed that the photoreduced platinum species mirror cisplatin reactivity toward DNA bases, thereby validating the efficacy of this approach.

Targeting strategies for improving the efficacy of nanomedicine in oncology

The use of nanoparticles as drug carriers has provided a powerful weapon in the fight against cancer. These nanocarriers are able to transport drugs that exhibit very different nature such as lipophilic or hydrophilic drugs and big macromolecules as proteins or RNA. Moreover, the external surface of these carriers can be decorated with different moieties with high affinity for specific membrane receptors of the tumoral cells to direct their action specifically to the malignant cells. The selectivity improvement yielded by these nanocarriers provided a significative enhancement in the efficacy of the transported drug, while the apparition of side effects in the host was reduced. Additionally, it is possible to incorporate targeting moieties selective for organelles of the cell, which improves even more the effect of the transported agents. In the last years, more sophisticated strategies such as the use of switchable, hierarchical or double targeting strategies have been proposed for overcoming some of the limitations of conventional targeting strategies. In this review, recent advances in the development of targeted nanoparticles will be described with the aim to present the current state of the art of this technology and its huge potential in the oncological field.

Dual-mode US/MRI nanoparticles delivering siRNA and Pt(iv) for ovarian cancer treatment

Phase-shifted dual-mode US/MRI nanoparticles (PFH/siRNA/Fe₃O₄@Pt(iv) NPs-cRGD) delivering si-survivin and Pt(iv) prodrug for enhancing ovarian cancer treatment and realizing real-time monitoring.

Nano-Based Systems and Biomacromolecules as Carriers for Metallodrugs in Anticancer Therapy

Since the discovery of cisplatin and its potency in anticancer therapy, the development of metallodrugs has been an active area of research. The large choice of transition metals, oxidation states, coordinating ligands, and different geometries, allows for the design of metal-based agents with unique mechanisms of action. Many metallodrugs, such as titanium, ruthenium, gallium, tin, gold, and copper-based complexes have been found to have anticancer activities. However, biological application of these agents necessitates aqueous solubility and low systemic toxicity. This minireview highlights the emerging strategies to facilitate the in vivo application of metallodrugs, aimed at enhancing their solubility and bioavailability, as well as improving their delivery to tumor tissues. The focus is on encapsulating the metal-based complexes into nanocarriers or coupling to biomacromolecules, generating efficacious anticancer therapies. The delivery systems for complexes of platinum, ruthenium, copper, and iron are discussed with most recent examples.

Clinical Applications of Carbon Nanomaterials in Diagnostics and Therapy

Nanomaterials have the potential to improve how patients are clinically treated and diagnosed. While there are a number of nanomaterials that can be used toward improved drug delivery and imaging, how these nanomaterials confer an advantage over other nanomaterials, as well as current clinical approaches is often application or disease specific. How the unique properties of carbon nanomaterials, such as nanodiamonds, carbon nanotubes, carbon nanofibers, graphene, and graphene oxides, make them promising nanomaterials for a wide range of clinical applications are discussed herein, including treating chemoresistant cancer, enhancing magnetic resonance imaging, and improving tissue regeneration and stem cell banking, among others. Additionally, the strategies for further improving drug delivery and imaging by carbon nanomaterials are reviewed, such as inducing endothelial leakiness as well as applying artificial intelligence toward designing optimal nanoparticle-based drug combination delivery. While the clinical application of carbon nanomaterials is still an emerging field of research, there is substantial preclinical evidence of the translational potential of carbon nanomaterials. Early clinically trial studies are highlighted, further supporting the use of carbon nanomaterials in clinical applications for both drug delivery and imaging.

Stimuli-Responsive Therapeutic Metallodrugs

The success of platinum-based anticancer agents has motivated the exploration of novel metal-based drugs for several decades, whereas problems such as drug-resistance and systemic toxicity hampered their clinical applications and efficacy. Stimuli-responsiveness of some metal complexes offers a good opportunity for designing site-specific prodrugs to maximize the therapeutic efficacy and minimize the side effect of metallodrugs. This review presents a comprehensive and up-to-date overview on the therapeutic stimuli-responsive metallodrugs that have appeared in the past two decades, where stimuli such as redox, pH, enzyme, light, temperature, and so forth were involved. The compounds are classified into three major categories based on the nature of stimuli, that is, endo-stimuli-responsive metallodrugs, exo-stimuli-responsive metallodrugs, and dual-stimuli-responsive metallodrugs. Representative examples of each type are discussed in terms of structure, response mechanism, and potential medical applications. In the end, future opportunities and challenges in this field are tentatively proposed. With diverse metal complexes being introduced, the foci of this review are pointed to platinum and ruthenium complexes.

Gastric cancer combination therapy: synthesis of a hyaluronic acid and cisplatin containing lipid prodrug coloaded with sorafenib in a nanoparticulate system to exhibit enhanced anticancer efficacy and reduced toxicity

Purpose

Gastric cancer is one of the most common human epithelial malignancies, and using nanoparticles (NPs) in the diagnosis and treatment of cancer has been extensively studied. The aim of this study was to develop hyaluronic acid (HA) containing lipid NPs coloaded with cisplatin (CDDP) and sorafenib (SRF) for the treatment of gastric cancer.

Materials and methods

HA and CDDP containing lipid prodrug was synthesized using polyethylene glycol (PEG) as a linker (HA-PEG-CDDP). HA-PEG-CDDP and SRF were entrapped into the lipid NPs by nanoprecipitation method (H-CS-NPs). The physicochemical and biochemical properties such as size, zeta potential, and drug release pattern were studied. In vitro viability was also evaluated with MKN28 and SGC7901 human gastric cancer cells. In vivo testing including biodistribution and accumulation in tumor tissue was applied in gastric tumor-bearing mice to confirm the inhibition of gastric cancer.

Results

H-CS-NP has a particle size of 173.2±5.9 nm, with a zeta potential of −21.5±3.2 mV. At day 21 of in vivo treatment, H-CS-NPs inhibited the tumor volume from 1,532.5±41.3 mm³ to 259.6±16.3 mm³ with no obvious body weight loss. In contrast, mice treated with free drugs had body weight loss from 20 to 15 g at the end of study.

Conclusion

The results indicate that H-CS-NPs enhanced the antitumor effect of drugs and reduced the systemic toxicity effects. It could be used as a promising nanomedicine for gastric cancer combination therapy.

Mitochondrial therapeutic interventions in Alzheimer's disease

Alzheimer's Disease (AD) is one of the most common age-related neurodegenerative diseases in the developed world. Treatment of AD is particularly challenging as the drug must overcome the blood brain barrier (BBB) before it can reach its target. Mitochondria are recognized as one of the most important targets for neurological drugs as the organelle is known to play a critical role in diverse cellular processes such as energy production and apoptosis regulation. Mitochondrial targeting was originally developed to study mitochondrial dysfunction and the organelles interaction with other sub-cellular organelles. The purpose of this review is to provide an overview of mitochondrial dysfunction and its role in late onset AD pathology. We then highlight recent antioxidant and enzymatic treatments used to alleviate mitochondrial dysfunction. Finally, we describe current applications of targeted mitochondrial delivery in the treatment of AD.

Glycyrrhetinic Acid Functionalized Graphene Oxide for Mitochondria Targeting and Cancer Treatment In Vivo

Mitochondria-mediated apoptosis (MMA) is a preferential option for cancer therapy due to the presence of cell-suicide factors in mitochondria, however, low permeability of mitochondria is a bottleneck for targeting drug delivery. In this paper, glycyrrhetinic acid (GA), a natural product from Glycyrrhiza glabra, is found to be a novel mitochondria targeting ligand, which can improve mitochondrial permeability and enhance the drug uptake of mitochondria. GA-functionalized graphene oxide (GO) is prepared and used as an effective carrier for targeted delivery of doxorubicin into mitochondria. The detailed in vitro and in vivo mechanism study shows that GA-functionalized GO causes a decrease in mitochondrial membrane potential and activates the MMA pathway. The GA-functionalized drug delivery system demonstrates highly improved apoptosis induction ability and anticancer efficacy compared to the non-GA-functionalized nanocarrier delivery system. The GA-functionalized nanocarrier also shows low toxicity, suggesting that it can be a useful tool for drug delivery.

Sustained Codelivery of Cisplatin and Paclitaxel via an Injectable Prodrug Hydrogel for Ovarian Cancer Treatment

The sustained release of both the hydrophilic drug and hydrophobic drug from one delivery system remains challenging in pharmaceutics and biomaterials science. The combination of hydrophilic cisplatin and hydrophobic paclitaxel (PTX) exhibits a clinical survival advantage compared with the individual drug therapy against various tumors such as ovarian cancer. In this study, a localized, long-term codelivery system of cisplatin and PTX was developed using an injectable and thermosensitive polymer-platinum(IV) conjugate hydrogel as the carrier. The thermosensitive Bi(mPEG-PLGA)-Pt(IV) (PtGel) conjugate was synthesized via covalently linking two mPEG-PLGA copolymers onto a Pt(IV) prodrug, and its concentrated aqueous solution exhibited a reversible sol-gel transition upon heating. Meanwhile, the core-corona micelles formed by the amphiphilic conjugates in water could serve as a reservoir for the solubilization of PTX, and thus an injectable binary drug-loaded hydrogel formulation was obtained. We also found that the introduction of PTX into the conjugate hydrogel decreased its sol-gel transition temperature and improved its gel strength. In vitro release experiments showed that both of the loaded drugs were released in a sustained manner for as long as 2.5 months, which was the longest combination delivery of these two drugs ever reported. In vitro cellular assays revealed that the dual-drug system exhibited a synergistic anticancer effect against ovarian cancer cells. Finally, using the SKOV-3 ovarian cancer xenograft mouse model, we demonstrated that a single injection of the PTX-loaded conjugate hydrogel system resulted in enhanced anticancer efficacy and significantly reduced the side effects, when compared with the multiple injections of the free drug combination.

Carbon Nanotube as a Tool for Fighting Cancer

In 2015, cancer was the cause of almost 22% of deaths worldwide. The high frequency of relapsing diseases and metastasis requires the development of new diagnostic and therapeutic approaches, and the use of nanomaterials is a promising tool for fighting cancer. Among the more extensively studied nanomaterials are carbon nanotubes (CNTs), synthesized as graphene sheets, whose spiral shape is varied in length and thickness. Their physicochemical features, such as the resistance to tension, and thermal and electrical conductivity, allow their application in several fields. In this review, we show evidence supporting the applicability of CNTs in biomedical practice as nanocarriers for drugs and immunomodulatory material, emphasizing their potential for use in cancer treatment.

Targeted killing of prostate cancer cells using antibody-drug conjugated carbon nanohorns

The ability of carbon nanohorns (CNHs) to cross biological barriers makes them potential carriers for delivery purposes. In this work, we report the design of a new selective antibody-drug nanosystem based on CNHs for the treatment of prostate cancer (PCa). In particular, cisplatin in a prodrug form and the monoclonal antibody (Ab) D2B, selective for PSMA⁺ cancer cells, have been attached to CNHs due to the current application of this antigen in PCa therapy. The hybrids Ab-CNHs, cisplatin-CNHs and functionalised-CNHs have also been synthesized to be used as control systems. The efficacy and specificity of the D2B-cisplatin-CNH conjugate to selectively target and kill PSMA⁺ prostate cancer cells have been demonstrated in comparison with other derivatives. The developed strategy to functionalise CNHs is fascinating because it can allow the fine tuning of both drug and Ab molecules attached to the nanostructure in order to modulate the activity of the nanosystem. Finally, the herein described methodology can be used for the incorporation of almost any drugs or Abs in the platforms in order to create new targeted drugs for the treatment of different diseases.

A Smart Europium-Ruthenium Complex as Anticancer Prodrug: Controllable Drug Release and Real-Time Monitoring under Different Light Excitations

A unique, dual-function, photoactivatable anticancer prodrug, RuEuL, has been tailored that features a ruthenium(II) complex linked to a cyclen-europium chelate via a π-conjugated bridge. Under irradiation at 488 nm, the dark-inactive prodrug undergoes photodissociation, releasing the DNA-damaging ruthenium species. Under evaluation-window irradiation (λ_irr = one-photon 350 nm or two-photon 700 nm), the drug delivery process can be quantitatively monitored in real-time because of the long-lived red europium emission. Linear relationships between released drug concentration and ESI-MS or luminescence responses are established. Finally, the efficiency of the new prodrug is demonstrated both in vitro RuEuL anticancer prodrug over some existing ones and open the way for decisive improvements in multipurpose prodrugs.

Mitochondria-Targeted Triphenylphosphonium-Based Compounds: Syntheses, Mechanisms of Action, and Therapeutic and Diagnostic Applications

Mitochondria are recognized as one of the most important targets for new drug design in cancer, cardiovascular, and neurological diseases. Currently, the most effective way to deliver drugs specifically to mitochondria is by covalent linking a lipophilic cation such as an alkyltriphenylphosphonium moiety to a pharmacophore of interest. Other delocalized lipophilic cations, such as rhodamine, natural and synthetic mitochondria-targeting peptides, and nanoparticle vehicles, have also been used for mitochondrial delivery of small molecules. Depending on the approach used, and the cell and mitochondrial membrane potentials, more than 1000-fold higher mitochondrial concentration can be achieved. Mitochondrial targeting has been developed to study mitochondrial physiology and dysfunction and the interaction between mitochondria and other subcellular organelles and for treatment of a variety of diseases such as neurodegeneration and cancer. In this Review, we discuss efforts to target small-molecule compounds to mitochondria for probing mitochondria function, as diagnostic tools and potential therapeutics. We describe the physicochemical basis for mitochondrial accumulation of lipophilic cations, synthetic chemistry strategies to target compounds to mitochondria, mitochondrial probes, and sensors, and examples of mitochondrial targeting of bioactive compounds. Finally, we review published attempts to apply mitochondria-targeted agents for the treatment of cancer and neurodegenerative diseases.

Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence

Carbon nanotubes (CNTs) have become an important nano entity for biomedical applications. Conventional methods of their imaging, often cannot be applied in biological samples due to an inadequate spatial resolution or poor contrast between the CNTs and the biological sample. Here we report a unique and effective detection method, which uses differences in conductivities of carbon nanotubes and HeLa cells. The technique involves the use of a helium ion microscope to image the sample with the surface charging artefacts created by the He⁺ and neutralised by electron flood gun. This enables us to obtain a few nanometre resolution images of CNTs in HeLa Cells with high contrast, which was achieved by tailoring the He⁺ fluence. Charging artefacts can be efficiently removed for conductive CNTs by a low amount of electrons, the fluence of which is not adequate to discharge the cell surface, resulting in high image contrast. Thus, this technique enables rapid detection of any conducting nano structures on insulating cellular background even in large fields of view and fine spatial resolution. The technique demonstrated has wider applications for researchers seeking enhanced contrast and high-resolution imaging of any conducting entity in a biological matrix - a commonly encountered issue of importance in drug delivery, tissue engineering and toxicological studies.

New Acridine Thiourea Gold(I) Anticancer Agents: Targeting the Nucleus and Inhibiting Vasculogenic Mimicry

Two new 1-acridin-9-yl-3-methylthiourea Au(I) DNA intercalators [Au(ACRTU)₂]Cl (2) and [Au(ACRTU) (PPh₃)]PF₆ (3) have been prepared. Both complexes were highly active in the human ovarian carcinoma cisplatin-sensitive A2780 cell line, exhibiting IC₅₀ values in the submicromolar range. Compounds 2 and 3 are also cytotoxic toward different phenotypes of breast cancer cell lines MDA-MB-231 (triple negative), SK-BR-3 (HER2+, ERα-, and ERβ-), and MCF-7 (ER+). Both complexes induce apoptosis through activation of caspase-3 in vitro. While inhibition of some proteins (thiol-containing enzymes) seems to be the main mechanism of action for cytotoxic gold complexes, 2 and 3 present a DNA-dependent mechanism of action. They locate in the cell nucleus according to confocal microscopy and transmission electronic microscopy. The binding to DNA resulted to be via intercalation as shown by spectroscopic methods and viscometry, exhibiting a dose-dependent response on topoisomerase I mediated DNA unwinding. In addition, 2 and 3 exhibit potent antiangiogenic effects and are also able to inhibit vasculogenic mimicry of highly invasive MDA-MB-231 cells.

Gadolinium and Platinum in Tandem: Real-time Multi-Modal Monitoring of Drug Delivery by MRI and Fluorescence Imaging

A novel dual-imaging cisplatin-carrying molecular cargo capable of performing simultaneous optical and MR imaging is reported herein. This long-lasting MRI contrast agent (r₁ relaxivity of 23.4 mM^-1s^-1 at 3T, 25 ^oC) is a photo-activated cisplatin prodrug (PtGdL) which enables real-time monitoring of anti-cancer efficacy. PtGdL is a model for monitoring the drug delivery and anti-cancer efficacy by MRI with a much longer retention time (24 hours) in several organs such as renal cortex and spleen than GdDOTA and its motif control GdL. Upon complete release of cisplatin, all PtGdL is converted to GdL enabling subsequent MRI analyses of therapy efficacy within its reasonably short clearance time of 4 hours. There is also responsive fluorescence enhancement for monitoring by photon-excitation.

Nanoparticle design considerations for molecular imaging of apoptosis: Diagnostic, prognostic, and therapeutic value

The present review analyzes various approaches for the design and synthesis of different nanoparticles for imaging and therapy. Nanoparticles for computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and optical imaging are discussed. The influence of nanoparticle size, shape, surface charge, composition, surface functionalization, active targeting and other factors on imaging and therapeutic efficacy is analyzed. Cyto- and genotoxicity of nanoparticles are also discussed. Special attention in the review is paid to the imaging of apoptotic tissues and cells in different diseases.

A nanocomplex of C60 fullerene with cisplatin: design, characterization and toxicity

The self-organization of C₆₀ fullerene and cisplatin in aqueous solution was investigated using the computer simulation, dynamic light scattering and atomic force microscopy techniques. The results evidence the complexation between the two compounds. The genotoxicity of С₆₀ fullerene, Cis and their complex was evaluated in vitro with the comet assay using human resting lymphocytes and lymphocytes after blast transformation. The cytotoxicity of the mentioned compounds was estimated by Annexin V/PI double staining followed by flow cytometry. The results clearly demonstrate that water-soluble C₆₀ fullerene nanoparticles (0.1 mg/mL) do not induce DNA strand breaks in normal and transformed cells. C₆₀ fullerene in the mixture with Cis does not influence genotoxic Cis activity in vitro, affects the cell-death mode in treated resting human lymphocytes and reduces the fraction of necrotic cells.

Design and cellular studies of a carbon nanotube-based delivery system for a hybrid platinum-acridine anticancer agent

A three-component drug-delivery system has been developed consisting of multi-walled carbon nanotubes (MWCNTs) coated with a non-classical platinum chemotherapeutic agent ([PtCl(NH3)2(L)]Cl (P3A1; L=N-(2-(acridin-9-ylamino)ethyl)-N-methylproprionimidamide) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-5000] (DSPE-mPEG). The optimized P3A1-MWCNTs are colloidally stable in physiological solution and deliver more P3A1 into breast cancer cells than treatment with the free drug. Furthermore, P3A1-MWCNTs are cytotoxic to several cell models of breast cancer and induce S-phase cell cycle arrest and non-apoptotic cell death in breast cancer cells. By contrast, free P3A1 induces apoptosis and allows progression to G2/M phase. Photothermal activation of P3A1-MWCNTs to generate mild hyperthermia potentiates their cytotoxicity. These findings suggest that delivery of P3A1 to cancer cells using MWCNTs as a drug carrier may be beneficial for combination cancer chemotherapy and photothermal therapy.