Upconversion Nanoparticle-Induced Multimode Photodynamic Therapy Based on a Metal-Organic Framework/Titanium Dioxide Nanocomposite

Virus-Inspired Gold Nanorod-Mesoporous Silica Core-Shell Nanoparticles Integrated with tTF-EG3287 for Synergetic Tumor Photothermal Therapy and Selective Therapy for Vascular Thrombosis

Synergetic therapy includes the combination of two or more conventional therapeutic approaches and can be used for tumor treatment by combining the advantages and avoiding the drawbacks of each type of treatment. In the present study, truncated tissue factor (tTF)-EG3287 fusion protein-encapsulated gold nanorod (GNR)-virus-inspired mesoporous silica core-shell nanoparticles (vinyl hybrid silica nanoparticles; VSNP) (GNR@VSNP-tTF-EG3287) were synthesized to achieve synergetic therapy by utilizing selective vascular thrombosis therapy (SVTT) and photothermal therapy (PTT). By integrating the targeted coagulation activity of tTF-EG3287 and the high tumor ablation effect of GNR@VSNP, local hyperthermia could induce a high percentage of apoptosis of vascular endothelial cells by using near-infrared light. This provided additional phospholipid sites for tTF-EG3287 and enhanced its procoagulant activity in vitro. In addition, the nanoparticles, which had unique topological viral structures, exhibited superior cellular uptake properties leading to significant antitumor efficacy. The in vivo antitumor results further demonstrated an interaction between SVTT and PTT, whereas the synergetic therapy (SVTT and PTT) achieved an enhanced effect, which was superior to the respective treatment efficacy of each modality or the additive effect of their individual efficacies. In summary, the synthesized GNR@VSNP-tTF-EG3287 exerted synergetic effects and enhanced the antitumor efficiency by avoiding multiple injections and suboptimal administration. These effects simultaneously affected both tumor blood supply and cancer cell proliferation. The data suggested that the integration of SVTT induced by tTF-EG3287 and PTT could provide potential strategies for synergetic tumor therapy.

Titanium and Iron Oxide Nanoparticles for Cancer Therapy: Surface Chemistry and Biological Implications

Currently, cancer is among the most challenging diseases due to its ability to continuously evolve into a more complex muldimentional system, in addition to its high capability to spread to other organs and tissues. In this context, the relevance of nanobiomaterials (NBMs) for the development of new more effective and less harmful treatments is increasing. NBMs provide the possibility of combining several functionalities on a single system, expectedly in a synergic way, to better perform the treatment and cure. However, the control of properties such as colloidal stability, circulation time, pharmacokinetics, and biodistribution, assuring the concentration in specific target tissues and organs, while keeping all desired properties, tends to be dependent on subtle changes in surface chemistry. Hence, the behavior of such materials in different media/environments is of uttermost relevance and concern since it can compromise their efficiency and safety on application. Given the bright perspectives, many efforts have been focused on the development of nanomaterials fulfilling the requirements for real application. These include robust and reproducible preparation methods to avoid aggregation while preserving the interaction properties. The possible impact of nanomaterials in different forms of diagnosis and therapy has been demonstrated in the past few years, given the perspectives on how revolutionary they can be in medicine and health. Considering the high biocompatibility and suitability, this review is focused on titanium dioxide– and iron oxide–based nanoagents highlighting the current trends and main advancements in the research for cancer therapies. The effects of phenomena, such as aggregation and agglomeration, the formation of the corona layer, and how they can compromise relevant properties of nanomaterials and their potential applicability, are also addressed. In short, this review summarizes the current understanding and perspectives on such smart nanobiomaterials for diagnostics, treatment, and theranostics of diseases.

Vitamin E-facilitated carbon monoxide pro-drug nanomedicine for efficient light-responsive combination cancer therapy

The quest to maximize therapeutic efficiency in cancer treatment requires innovative delivery nanoplatforms capable of employing different modules simultaneously. Combination therapy has proven to be one of the best anticancer strategies so far. Herein, we have developed a lipid-encapsulated nanoplatform that combines chemotherapy with photoresponsive gas therapy for colon cancer treatment. Carbon monoxide releasing molecules (CORMs) and vitamin E analogues (pure/pegylated α-tocopheryl succinate; α-TOS) were co-loaded into the lipid layer with core-shell upconversion nanoparticles (UCNPs), which converted 808 nm light to 360 nm photons to trigger CO release at the tumor site. This folic acid (FA)-targeting nanomedicine (Lipid/UCNP/CORM/α-TOS/FA: LUCTF) possessed a cancer-targeting ability and a light-triggered CO release ability for synergistic apoptosis of HCT116 cells via enhanced ROS generation and mitochondrial membrane breaking. In vivo data have confirmed the significantly enhanced therapeutic efficacy of LUCTF without any significant biosafety issues after intravenous administration. Thus, nanomedicine LUCTF represents a novel way for efficient cancer therapy via combining locally released CO and a compatible chemotherapeutic agent (e.g. α-TOS).

Porphyrin-Containing MOFs and COFs as Heterogeneous Photosensitizers for Singlet Oxygen-Based Antimicrobial Nanodevices

Visible-light irradiation of porphyrin and metalloporphyrin dyes in the presence of molecular oxygen can result in the photocatalytic generation of singlet oxygen (¹O₂). This type II reactive oxygen species (ROS) finds many applications where the dye, also called the photosensitizer, is dissolved (i.e., homogeneous phase) along with the substrate to be oxidized. In contrast, metal-organic frameworks (MOFs) are insoluble (or will disassemble) when placed in a solvent. When stable as a suspension, MOFs adsorb a large amount of O₂ and photocatalytically generate ¹O₂ in a heterogeneous process efficiently. Considering the immense surface area and great capacity for gas adsorption of MOFs, they seem ideal candidates for this application. Very recently, covalent-organic frameworks (COFs), variants where reticulation relies on covalent rather than coordination bonds, have emerged as efficient photosensitizers. This comprehensive mini review describes recent developments in the use of porphyrin-based or porphyrin-containing MOFs and COFs, including nanosized versions, as heterogeneous photosensitizers of singlet oxygen toward antimicrobial applications.

Solutions to the Drawbacks of Photothermal and Photodynamic Cancer Therapy

Phototherapy such as photothermal therapy and photodynamic therapy in cancer treatment has been developed quickly over the past few years for its noninvasive nature and high efficiency. However, there are still many drawbacks in phototherapy that prevent it from clinical applications. Thus, scientists have designed different systems to overcome the issues associated with phototherapy, including enhancing the targeting ability of phototherapy, low-temperature photothermal therapy, replacing near-infrared light with other excitation sources, and so on. This article discusses the problems and shortcomings encountered in the development of phototherapy and highlights possible solutions to address them so that phototherapy may become a useful cancer treatment approach in clinical practice. This article aims to give a brief summary about current research advancements in phototherapy research and provides a quick guideline toward future developments in the field.

Multifunctional metal-organic framework heterostructures for enhanced cancer therapy

Metal-organic frameworks (MOFs) are an emerging class of molecular crystalline materials built from metal ions or clusters bridged by organic linkers. By taking advantage of their synthetic tunability and structural regularity, MOFs can hierarchically integrate nanoparticles and/or biomolecules into a single framework to enable multifunctions. The MOF-protected heterostructures not only enhance the catalytic capacity of nanoparticle components but also retain the biological activity of biomolecules in an intracellular microenvironment. Therefore, the multifunctional MOF heterostructures have great advantages over single components in cancer therapy. In this review, we comprehensively summarize the general principle of the design and functional modulation of nanoscaled MOF heterostructures, and biomedical applications in enhanced therapy within the last five years. The functions of MOF heterostructures with a controlled size can be regulated by designing various functional ligands and in situ growth/postmodification of nanoparticles and/or biomolecules. The advances in the application of multifunctional MOF heterostructures are also explored for enhanced cancer therapies involving photodynamic therapy, photothermal therapy, chemotherapy, radiotherapy, immunotherapy, and theranostics. The remaining challenges and future opportunities in this field, in terms of precisely localized assembly, maximizing composite properties, and processing new techniques, are also presented. The introduction of multiple components into one crystalline MOF provides a promising approach to design all-in-one theranostics in clinical treatments.

Modified nanoscale metal organic framework-based nanoplatforms in photodynamic therapy and further applications

Photodynamic therapy (PDT) has emerged as a modality in cancer treatment because it is less invasive and highly selective compared with conventional chemotherapy and radiation therapy. Nanoscale metal organic frameworks (nMOFs) have exhibited great potential for use in constructing nanoplatforms for improved PDT because of their unique structural advantages such as large surface areas, high porosities, tunable compositions and various other modifications. The large majority of current nMOF-based systems employ specific modifying groups to overcome the deficiencies previously observed when using older nMOFs in PDT. In this review, we summarize modifications to these systems such as enhancing singlet oxygen generation by introducing photoactive agents, alleviating tumor hypoxia and engineering active targeting abilities. The applications of MOF-based nanoparticles in synergistic cancer therapies that include PDT, as well as in theranostics are also discussed. Finally, we discuss some of the challenges faced in this field and the future prospects for the use of nMOFs in PDT.

Lanthanide-Activated Nanoparticles: A Toolbox for Bioimaging, Therapeutics, and Neuromodulation

Owing to their unique features, the past decade has witnessed rapid developments of lanthanide-activated nanoparticles for biological applications. These include highly tunable upconverting and downshifting photoluminescence when illuminated in deep tissue, excellent photostability against blinking and bleaching effects, biocompatibility through versatile surface modification, and ease of achieving multifunctionality, as well as satisfactory signal output. These attributes make lanthanide-doped nanoparticles an ideal toolbox for advanced bioimaging and next-generation therapeutics.The interest in lanthanide-doped nanoparticles for biomedical research arises from their unique optical properties in response to deep-tissue-penetrable light sources. Upon near-infrared irradiation, these nanoparticles with properly doped emitters display photon upconversion with large anti-Stokes shifts and broad-spectrum tunability from the ultraviolet to the visible. It is also possible to achieve orthogonal photoluminescence with variations in wavelength and lifetime. Coupled with surface ligands, dyes, biomolecules, or other types of functional nanomaterials, lanthanide-doped nanoparticles offer new opportunities for applications in bioimaging, advanced oncotherapy, and neuromodulation. Given the possibility of locating downshifting luminescence at "biological transmission windows", exquisite design of lanthanide-doped nanoparticles also enables deep-tissue imaging with high spatial resolution. In addition, these nanoparticles can respond to high-energy photons, such as X-rays, to trigger nonradioactive and radiative pathways, making it possible to develop high-sensitivity X-ray detectors. Precise control of paramagnetic lanthanide ions in nanocrystal lattices also provides advanced materials for high-performance magnetic resonance imaging in medical diagnostics and biomedical research. Full consideration of fundamental attributes of lanthanide-doped nanoparticles will facilitate the design of multifunctional and sensitive probes and improve diagnostic and therapeutic outcomes.In this Account, we categorize various lanthanide-activation strategies into three modes: near-infrared excitation, X-ray irradiation, and magnetic field stimulation. We introduce energy manipulations in upconverting, downshifting, and persistence luminescence in spectral and time domains and discuss how they can be applied in biological practices. We assess general design principles for lanthanide-activated nanosystems with multiple modalities of bioimaging, oncotherapy, and neuromodulation. We also review the current state-of-the-art in the field of lanthanide-based theranostic nanoplatforms, with particular emphasis on energy conversion and nano-/biointerfacing as well as emerging bioapplications. In this context, we also highlight recent advances in controlling optical properties of nanoplatforms for single- or multimodal bioimaging, stimulus-responsive phototherapy, and optogenetics. Finally, we discuss future opportunities and challenges of this exciting research field.

Recent Advances on Rare Earth Upconversion Nanomaterials for Combined Tumor Near-Infrared Photoimmunotherapy

Cancer has been threatening the safety of human life. In order to treat cancer, many methods have been developed to treat tumor, such as traditional therapies like surgery, chemotherapy, radiotherapy, as well as new strategies like photodynamic therapy, photothermal therapy, sonodynamic therapy, and other emerging therapies. Although there are so many ways to treat tumors, these methods all face the dilemma that they are incapable to cope with metastasis and recurrence of tumors. The emergence of immunotherapy has given the hope to conquer the challenge. Immunotherapy is to use the body's own immune system to stimulate and maintain a systemic immune response to form immunological memory, resist the metastasis and recurrence of tumors. At the same time, immunotherapy can combine with other treatments to exhibit excellent antitumor effects. Upconversion nanoparticles (UCNPs) can convert near-infrared (NIR) light into ultraviolet and visible light, thus have good performance in bioimaging and NIR triggered phototherapy. In this review paper, we summarize the design, fabrication, and application of UCNPs-based NIR photoimmunotherapy for combined cancer treatment, as well as put forward the prospect of future development.

Recent development of amorphous metal coordination polymers for cancer therapy

Nanoscale metal coordination polymers (NCPs), built from metal ions and organic ligands, have attracted tremendous interest in biomedical applications. This is mainly due to their mesoporous structure, tunable size and morphology and versatile functionality. NCPs can be further divided into nanoscale metal-organic frameworks (NMOFs) and amorphous coordination polymer particles (ACPPs) depending on their structural crystallinity. NMOFs as nanocarriers have been extensively reviewed. However, the highlights of ACPPs as theranostic nanoplatforms are still limited. In this review, the recent progress of ACPPs as theranostic nanoplatforms is summarized based on what types of organic linkers used. The ACPPs are divided into three main parts: photosensitizers-based ACPPs, chemical drugs-based ACPPs, and biomolecules-based ACPPs. Finally, the prospects and challenges of the ACPPs for enhanced biomedical applications are also discussed. STATEMENT OF SIGNIFICANCE: Over the last decades, amorphous metal coordination polymers (ACPPs), constructed by metal ions and organic linkers, have attracted enormous interest in cancer treatment owing to their high drug loading capability, facile synthetic procedures, low long-term toxicity, and mild preparation conditions. In this review, we highlight the recent progress of ACPPs for biomedical application based on different types of organic building blocks including photosensitizers, chemical drugs, and biomolecules. Moreover, the prospects and challenges of ACPPs for clinical application are also discussed. We hope this review entitled "Recent development of amorphous metal coordination polymers for cancer therapy" would arise the researchers' interest in this field to accelerate their clinical application in cancer therapy.

Photodynamic Nanophotosensitizers: Promising Materials for Tumor Theranostics

Photodynamic theranostics/therapy (PDT) is a potential strategy for selectively imaging malignant sites and treating cancer via a non-invasive therapeutic method. Photosensitizers, the crucial components of PDT, enable colocalization of photons and light, and photon/light therapy in the therapeutic window of 400-900 nm exhibits photocytotoxicity to tumor cells. Due to their high biostability and photocytotoxicity, nanophotosensitizers (NPSs) are of much interest for malignant tumor theranostics at present. NPS-activated photons transfer energy through the absorption of a photon and convert molecular oxygen to the singlet reactive oxygen species, which leads to apoptosis and necrosis. Moreover, NPSs modified by polymers, including PLGA, PEG-PLA, PDLLA, PVCL-g-PLA, and P(VCL-co-VIM)-g-PLA, exhibit excellent biocompatibility, and a tumor-targeting molecule linked on the nanoparticle surface can precisely deliver NPSs into the tumor region. The development of NPSs will accelerate the progress in tumor theranostics through the photon/light pathway.

Autophagy regulates the Wnt/GSK3β/β-catenin/cyclin D1 pathway in mesenchymal stem cells (MSCs) exposed to titanium dioxide nanoparticles (TiO2NPs)

The application of titanium dioxide nanoparticles (TiO2NPs) is on the increase, and so the number of studies dedicated to describing this material's biological effects. Previous studies have presented results indicating the controversial impact of TiO2NPs on cell fate regarding death and survival. We speculate that this may be due to focusing on each of the subject cells as an isolated individual. In this study, we made a difference by looking at the subject cells as an interrelated population. Specifically, we exposed mesenchymal stem cells (MSCs) to TiO2NPs and observed cell death and stimulation of proliferation among the cell population. Our data shows that the exposure to TiO2NPs initiated autophagy, which led to an increase in extracellular Wnt protein levels and increased Wnt/GSK3β/β-catenin/cyclin D1 signalling in the cell population. Autophagy inhibitor repressed the effects of TiO2NPs, which indicates that β-catenin regulation was dependent on TiO2NPs-induced autophagy. The inhibition of β-catenin resulted in dysregulation of cyclin D1 protein expression level. In conclusion, following exposure to TiO2NPs, MSCs undergo autophagy, which induces cell proliferation among the cell population by upregulation of cyclin D1 through the Wnt/GSK3β/β-catenin pathway.

Specific Oxide Nanoclusters Enhance Intracellular Reactive Oxygen Species for Cancer-Targeted Therapy

Bio-nanotechnology based cancer therapeutics exponentially increase every year. A therapeutic strategy to induce intracellular reactive oxygen species (ROS) has received promising success in oncotherapy. In this study, the new strategy has been exploited by the treatment of iridium (Ir) and Fe²⁺ ions with cancer cells to biosynthesize the biocompatible fluorescent iridium oxide (IrO₂) and iron oxide nanoclusters (NCs) under the specific redox heterogeneous microenvironment of these diseased cells and tumors. The hydroxyl radical produced by the presence of Fe²⁺ and H₂O₂ in cancer cells apparently increased the ROS level in cancer cells during the process of biosynthesized NCs and, hence, simultaneously instigated apoptosis of relevant cells. Therefore, intracellular ROS-mediated in situ biosynthesis of IrO₂ and iron oxide NCs may also act as anticancer agents and provide a promising pathway for targeted cancer therapy.