Adsorption of l-Cysteine and Cysteamine on Zinc Oxide Nanoparticles

The reaction of l-cysteine and cysteamine hydrochloride with zinc oxide nanoparticles (ZnO NPs), by stirring excess reactant with the NPs in ethanol, has been studied by thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. l-Cysteine adsorption occurs via the thiol functional group, and there is no evidence for bonding via the carboxylic acid or amine functionalities. However, Raman spectroscopy and XPS reveal some protonated thiol, suggesting unbound l-cysteine is also present, as confirmed by XRD that shows the presence of l-cysteine crystallites. In the case of cysteamine/ZnO, TGA indicates that a large fraction of the sample is organic, and Raman spectroscopy reveals a dramatic shift in the C-S stretch from 796 cm-1 for unreacted cysteamine to 837 cm-1 for the reacted cysteamine. It is postulated that the acidic and chelating nature of the reaction causes dissolution of some Zn2+ ions that form a Zn(II) coordination complex with cysteamine. These studies have implications for biomolecular applications in which ZnO nanoparticles are used for biosensors, bioimaging, and drug delivery.

The wonders of X-PDT: an advance route to cancer theranostics

Global mortality data indicates cancer as the second-leading cause of death worldwide. Therefore, there's a pressing need to innovate effective treatments to address this significant medical and societal challenge. In recent years, X-ray-induced photodynamic therapy (X-PDT) has emerged as a promising advancement, revolutionizing traditional photodynamic therapy (PDT) for deeply entrenched malignancies by harnessing penetrating X-rays as external stimuli. Recent developments in X-ray photodynamic therapy have shown a trend toward minimizing radiation doses to remarkably low levels after the proof-of-concept demonstration. Early detection and real-time monitoring are crucial aspects of effective cancer treatment. Sophisticated X-ray imaging techniques have been enhanced by the introduction of X-ray luminescence nano-agents, alongside contrast nanomaterials based on X-ray attenuation. X-ray luminescence-based in vivo imaging offers excellent detection sensitivity and superior image quality in deep tissues at a reasonable cost, due to unhindered penetration and unimpeded auto-fluorescence of X-rays. This review emphasizes the significance of X-ray responsive theranostics, exploring their mechanism of action, feasibility, biocompatibility, and promising prospects in imaging-guided therapy for deep-seated tumors. Additionally, it discusses promising applications of X-PDT in treating breast cancer, liver cancer, lung cancer, skin cancer, and colorectal cancer.

Ultraviolet (UV) radiation: a double-edged sword in cancer development and therapy

It has long been widely acknowledged that ultraviolet (UV) light is an environment risk factor that can lead to cancer, particularly skin cancer. However, it is worth noting that UV radiation holds potential for cancer treatment as a relatively high-energy electromagnetic wave. With the help of nanomaterials, the role of UV radiation has caught increasing attention in cancer treatment. In this review, we briefly summarized types of UV-induced cancers, including malignant melanoma, squamous cell carcinoma, basal cell carcinoma, Merkel cell carcinoma. Importantly, we discussed the primary mechanisms underlying UV carcinogenesis, including mutations by DNA damage, immunosuppression, inflammation and epigenetic alterations. Historically limited by its shallow penetration depth, the introduction of nanomaterials has dramatically transformed the utilization of UV light in cancer treatment. The direct effect of UV light itself generally leads to the suppression of cancer cell growth and the initiation of apoptosis and ferroptosis. It can also be utilized to activate photosensitizers for reactive oxygen species (ROS) production, sensitize radiotherapy and achieve controlled drug release. Finally, we comprehensively weigh the significant risks and limitations associated with the therapeutic use of UV radiation. And the contradictory effect of UV exposure in promoting and inhibiting tumor has been discussed. This review provides clues for potential clinical therapy as well as future study directions in the UV radiation field. The precise delivery and control of UV light or nanomaterials and the wavelength as well as dose effects of UV light are needed for a thorough understanding of UV radiation.

A Biocompatible, Highly Sensitive, and Non-Enzymatic Glucose Electrochemical Sensor Based on a Copper-Cysteamine (Cu-Cy)/Chitosan-Modified Electrode

A biocompatible, highly sensitive, and enzyme-free glucose electrochemical sensor was developed based on a copper-cysteamine (Cu-Cy)-modified electrode. The catalytically active biocompatible material Cu-Cy was immobilized on the electrode surface by the natural polymer chitosan (CTS). The electrochemical characterization and glucose response of the Cu-Cy/CTS/glassy carbon electrode (GCE) were investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and constant potential amperometry. The significant electrocatalytic activity of Cu-Cy to the oxidation of glucose in an alkaline environment was revealed. Several crucial parameters, including the number of scanning cycles for electrode activation, applied potential, and the contents of Cu-Cy and chitosan, were investigated to understand their impact on the sensor's response. The proposed sensing platform exhibited linear ranges of 2.7 μM to 1.3 mM and 1.3 mM to 7.7 mM for glucose detection, coupled with high sensitivity (588.28 and 124.42 μA·mM-1·cm-2), and commendable selectivity and stability. Moreover, a Cu-Cy/CTS-modified screen-printed electrode (SPE) was further developed for portable direct detection of glucose in real samples.

Exploring the combined impact of cisplatin and copper-cysteamine nanoparticles through Chemoradiation: An in-vitro study

Copper-Cysteamine nanoparticles (Cu-Cy NPs) have emerged as promising radiosensitizers in cancer treatment. This study aims to investigate the combined therapeutic effect of these nanoparticles and cisplatin using a clinical linear accelerator to enhance the efficacy of chemoradiation therapy for cervical cancer. Following successful synthesis and characterization of Cu-Cy NPs, the cytotoxicity effect of these nanoparticles and cisplatin in various concentrations was evaluated on HeLa cancer cells, individually and in combination. Additionally, the radiobiological effects of these agents were investigated under a 6MV linear accelerator. At a concentration of 25 mg/L, Cu-Cy NPs displayed no significant cytotoxicity toward HeLa cancer cells. However, when combined with 2Gy X-ray irradiation at this concentration, the nanoparticles demonstrated a potent radiosensitizing effect. Notably, cell viability and migration rate in the combination group (Cu-Cy NPs + cisplatin + radiation) were significantly reduced compared to the radiation-alone group. Additionally, the combination treatment induced a significantly higher rate of apoptosis compared to the radiation-alone group. Overall, Cu-Cy NPs exhibited a significant dose-dependent synergistic enhancement of radiation efficacy when combined with cisplatin under X-ray exposure, and may provide a promising approach to improve the therapeutic effect of conventional radiation therapy.

Combination of disulfiram and Copper-Cysteamine nanoparticles induces mitochondria damage and promotes apoptosis in endometrial cancer

Endometrial cancer (EC) stands as one of the most prevalent gynecological malignancies affecting women, with its incidence and disease-related mortality steadily on the rise. Disulfiram (DSF), an FDA-approved medication primarily used for treating alcohol addiction, has exhibited promising anti-tumor properties. Studies have revealed DSF's capacity for enhanced anti-tumor activity, particularly when combined with copper. The novel Copper-Cysteamine (CuCy) compound, Cu3Cl(SR)2 (R[bond, double bond]CH2CH2NH2), showcases photodynamic effects and demonstrates significant anti-tumor potential under various conditions, including exposure to ultraviolet light, X-ray, microwave, and ultrasound. This study delves into exploring the synergistic anti-tumor effects and underlying mechanisms by utilizing copper-cysteamine in conjunction with DSF against endometrial cancer. The investigation involved comprehensive analyses encompassing in vitro experiments utilizing Ishikawa cells, in vivo studies, and transcriptomic analyses. Remarkably, the combined administration of both compounds at a low dose of 0.5 μM exhibited pronounced efficacy in impeding tumor growth, inhibiting blood vessel formation, and stimulating cell apoptosis. Notably, experiments involving transplanted tumors in nude mice vividly demonstrated the significant in vivo anti-tumor effects of this combination treatment. Detailed examination through transmission electron microscopy unveiled compelling evidence of mitochondrial damage, cellular swelling, and rupture, indicative of apoptotic changes in morphology due to the combined treatment. Moreover, transcriptomic analysis unveiled substantial downregulation of mitochondrial-related genes at the molecular level, coupled with a significant hindrance in the DNA repair pathway. These findings strongly suggest that the combined application of CuCy and DSF induces mitochondrial impairment in Ishikawa cells, thereby fostering apoptosis and ultimately yielding potent anti-tumor effects.

A near-infrared aggregation-induced emission photosensitizer targeting mitochondria for depleting Cu2+ to trigger light-activated cancer cells oncosis

Abnormally high levels of copper in tumors stimulate malignant proliferation and migration of cancer cells, which proposes a formidable challenge for the thorough therapy of malignant tumors. In this work, we developed a reliable, mitochondria-targeted near-infrared aggregation-induced emission fluorescent probe, TTQ-Th, whose thiourea moiety specifically could recognize mitochondria even both upon loss of mitochondrial membrane potential or in fixated cells, and can capture copper overexpressed by tumor cells, leading to severe copper deficiency. In parallel, TTQ-Th can generate sufficient reactive oxygen species (ROS) upon photoexcitation, while copper deficiency inhibits expression of related copper-based enzymes, resulting in a decline in ATP production. Such energy deficiency, combined with reduced MMP and elevated oxidative stress can lead to critical cell oncosis. Both in vitro and intracellular experiments can illustrate that the elevated ROS has remarkable damage to tumor cells and contributes to the elimination of the primary tumor, while copper deficiency further hinder tumor cell migration and induces G0/G1 cell cycle arrest in a dose-dependent manner, which is an efficacious strategy for the treatment of malignant tumors.

Exploring the Use of Intracellular Chelation and Non-Iron Metals to Program Ferroptosis for Anticancer Application

The discovery of regulated cell death (RCD) revolutionized chemotherapy. With caspase-dependent apoptosis initially being thought to be the only form of RCD, many drug development strategies aimed to synthesize compounds that turn on this kind of cell death. While yielding a variety of drugs, this approach is limited, given the acquired resistance of cancers to these drugs and the lack of specificity of the drugs for targeting cancer cells alone. The discovery of non-apoptotic forms of RCD is leading to new avenues for drug design. Evidence shows that ferroptosis, a relatively recently discovered iron-based cell death pathway, has therapeutic potential for anticancer application. Recent studies point to the interrelationship between iron and other essential metals, copper and zinc, and the disturbance of their respective homeostasis as critical to the onset of ferroptosis. Other studies reveal that several coordination complexes of non-iron metals have the capacity to induce ferroptosis. This collective knowledge will be assessed to determine how chelation approaches and coordination chemistry can be engineered to program ferroptosis in chemotherapy.

Mn-doped Ti-based MOFs for magnetic resonance imaging-guided synergistic microwave thermal and microwave dynamic therapy of liver cancer

Currently, precise ablation of tumors without damaging the surrounding normal tissue is still an urgent problem for clinical microwave therapy of liver cancer. Herein, we synthesized Mn-doped Ti MOFs (Mn–Ti MOFs) nanosheets by in-situ doping method and applied them for microwave therapy. Infrared thermal imaging results indicate Mn–Ti MOFs can rapidly increase the temperature of normal saline, attributing to the porous structure improving microwave-induced ion collision frequency. Moreover, Mn–Ti MOFs show higher ¹O₂ output than Ti MOFs under 2 W of low-power microwave irradiation due to the narrower band-gap after Mn doping. At the same time, Mn endows the MOFs with a desirable T₁ contrast of magnetic resonance imaging (r₂/r₁ = 2.315). Further, results on HepG2 tumor-bearing mice prove that microwave-triggered Mn–Ti MOFs nearly eradicate the tumors after 14 days of treatment. Our study offers a promising sensitizer for synergistic microwave thermal and microwave dynamic therapy of liver cancer.

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Mn-doped Ti-MOFs nanosheets (Mn–Ti MOFs) were synthesized as novel microwave sensitizers.

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Mn–Ti MOFs can significantly generate heat and produce ROS under low-power microwave irradiation.

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The combination of microwave thermal therapy and microwave dynamic therapy can effectively inhibit the growth of tumor cells in vitro and in vivo.

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The microwave sensitizers have potential application in MRI-guided microwave therapy for liver cancer.

AIEgens/Mitochondria Nanohybrids as Bioactive Microwave Sensitizers for Non-Thermal Microwave Cancer Therapy

Aggregation-induced emission luminogens (AIEgens) are widely used as photosensitizers for image-guided photodynamic therapy (PDT). Due to the limited penetration depth of light in biological tissues, the treatments of deep-seated tumors by visible-light-sensitized aggregation-induced emission (AIE) photosensitizers are severely hampered. Microwave dynamic therapy attracts much attention because microwave irradiation can penetrate very deep tissues and sensitize the photosensitizers to generate reactive oxygen species (ROS). In this work, a mitochondrial-targeting AIEgen (DCPy) is integrated with living mitochondria to form a bioactive AIE nanohybrid. This nanohybrid can not only generate ROS under microwave irradiation to induce apoptosis of deep-seated cancer cells but also reprogram the metabolism pathway of cancer cells through retrieving oxidative phosphorylation (OXPHOS) instead of glycolysis to enhance the efficiency of microwave dynamic therapy. This work demonstrates an effective strategy to integrate synthetic AIEgens and natural living organelles, which would inspire more researchers to develop advanced bioactive nanohybrids for cancer synergistic therapy.

Reactive oxygen species-upregulating nanomedicines towards enhanced cancer therapy

Reactive oxygen species (ROS) play a crucial role in physiological and pathological processes, emerging as a therapeutic target in cancer. Owing to the high concentration of ROS in solid tumor tissues, ROS-based treatments, such as photodynamic therapy and chemodynamic therapy, and ROS-responsive drug delivery systems have been widely explored to powerfully and specifically suppress tumors. However, their anticancer efficacy is still hampered by the heterogeneous ROS levels, and thus comprehensively upregulating the ROS levels in tumor tissues can ensure an enhanced therapeutic effect, which can further sensitize and/or synergize with other therapies to inhibit tumor growth and metastasis. Herein, we review the recently emerging drug delivery strategies and technologies for increasing the H₂O₂, ˙OH, ¹O₂, and ˙O₂^- concentrations in cancer cells, including the efficient delivery of natural enzymes, nanozymes, small molecular biological molecules, and nanoscale Fenton-reagents and semiconductors and neutralization of intracellular antioxidant substances and localized input of mechanical and electromagnetic waves (such as ultrasound, near infrared light, microwaves, and X-rays). The applications of these ROS-upregulating nanosystems in enhancing and synergizing cancer therapies including chemotherapy, chemodynamic therapy, phototherapy, and immunotherapy are surveyed. In addition, we discuss the challenges of ROS-upregulating systems and the prospects for future studies.

Copper-cysteamine nanoparticle-mediated microwave dynamic therapy improves cancer treatment with induction of ferroptosis

Photodynamic Therapy (PDT) holds a great promise for cancer patients, however, due to the hypoxic characteristics of most solid tumors and the limited penetration depth of light in tissues, the extensive clinical application of PDT is limited. Herein, we report microwave induced copper-cysteamine (Cu-Cy) nanoparticles-based PDT as a promising cancer treatment to overcome cancer resistance in combination with ferroptosis. The treatment efficiency of Cu-Cy-mediated microwave dynamic therapy (MWDT) tested on HCT15 colorectal cancer (CRC) cells via cell titer-blue cell viability assay and live/dead assay reveal that Cu-Cy upon MW irradiation can effectively destroy HCT15 CRC cells with average IC-50 values of 20 μg/mL. The cytotoxicity of Cu-Cy to tumor cells after MW stimulation can be alleviated by ferroptosis inhibitor. Furthermore, Cu-Cy mediated MWDT could deplete glutathione peroxide 4 (GPX4) and enhance lipid peroxides (LPO) and malondialdehyde (MDA). Our findings demonstrate that MW-activated Cu-Cy killed CRC cells by inducing ferroptosis. The superior in vivo antitumor efficacy of the Cu-Cy was corroborated by a HCT15 tumor-bearing mice model. Immunohistochemical experiments showed that the GPX4 expression level in Cu-Cy + MW group was significantly lower than that in other groups. Overall, these findings demonstrate that Cu-Cy nanoparticles have a safe and promising clinical application prospect in MWDT for deep-seated tumors and effectively inhibit tumor cell proliferation by inducing ferroptosis, which provides a potential solution for cancer resistance.

Advanced techniques for performing photodynamic therapy in deep-seated tissues

Photodynamic therapy (PDT) is a promising localized cancer treatment modality. It has been used successfully to treat a range of dermatological conditions with comparable efficacy to conventional treatments. However, some drawbacks limit the clinical utility of PDT in treating deep-seated tumors. Notably, the penetration limitation of UV and visible light, commonly applied to activate photosensitizers, makes PDT incompetent in treating deep-seated tumors. Development in light delivery technologies, especially fiber optics, led to improved clinical strategies for accessing deep tissues for irradiation. However, PDT efficacy issues remained partly due to light penetration limitations. In this review, we first summarized the current PDT applications for deep-seated tumor treatment. Then, the most recent progress in advanced techniques to overcome the light penetration limitation in PDT, including using functional nanomaterials that can either self-illuminate or be activated by near-infrared (NIR) light and X-rays as transducers, and implantable light delivery devices were discussed. Finally, current challenges and future opportunities of these technologies were discussed, which we hope may inspire the development of more effective techniques to enhance PDT efficacy against deep-seated tumors.

Synchronous enhancement of upconversion and NIR-IIb photoluminescence of rare-earth nanoprobes for theranostics

This study develops a multifunctional molecular optical nanoprobe (SiO₂@Gd₂O₃: Yb³⁺/Er³⁺/Li⁺@Ce6/MC540) with a unique core-satellite form. The rare-earth doped nanodots with good crystallinity are uniformly embedded on the surface of a hydrophilic silica core, and the nanoprobe can emit near-infrared-IIb (NIR-IIb) luminescence for imaging as well as visible light that perfectly matches the absorption bands of two included photosensitizers under 980 nm irradiation. The optimal NIR-IIb emission and upconversion efficiency are attainable via regulating the doping ratios of Yb³⁺, Er³⁺ and Li⁺ ions. The relevant energy transfer mechanism was addressed theoretically that underpins rare-earth photoluminescence where energy back-transfer and cross relaxation processes play pivotal roles. The nanoprobe can achieve an excellent dual-drive photodynamic treatment performance, verified by singlet oxygen detections and live-dead cells imaging assays, with a synergistic effect. And a brightest NIR-IIb imaging was attained in tumoral site of mouse. The nanoprobe has a high potential to serve as a new type of optical theranostic agent for tumor.

Defect Engineering Triggers Exceptional Sonodynamic Activity of Manganese Oxide Nanoparticles for Cancer Therapy

Sonodynamic therapy (SDT) has received increasing interest in cancer treatment, but its clinical application is still constrained by the low activity of sonosensitizers and their unclear mechanism. Herein, a kind of oxygen-deficient manganese oxide (MnOx) nanoparticles with greatly enhanced sonodynamic activity and good biocompatibility is developed as an advanced sonosensitizer. The introduced oxygen defects can remarkably enhance the electrical conductivity of manganese oxide (MnO) nanoparticles and serve as charge trapping sites to prohibit the electron-hole pair recombination upon ultrasound (US) irradiation. Such distinct merits promote the generation of reactive oxygen species (ROS), making MnOx as a decent sonosensitizer for SDT, and thus endowing MnOx with higher ROS production under US irradiation. As a demonstration, the MnOx nanoparticles decorated by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (MnOx-DSPE-PEG), a biocompatible coverage to enhance the dispersion ability, achieve a superior tumor killing efficiency of 96%, substantially higher than the MnO-DSPE-PEG counterpart (9%). Our experimental results also reveal that MnOx-DSPE-PEG nanoparticles induce the death of tumor cells by targeting polyunsaturated fatty acids in their membrane with US-triggered ROS. Furthermore, the as-designed sonosensitizers exhibit negligible toxicity toward the treated mice.

Porphyrin-Based Nanoparticles: A Promising Phototherapy Platform

Phototherapy, including photodynamic therapy and photothermal therapy, is an emerging form of non-invasive treatment. The combination of imaging technology and phototherapy is becoming an attractive development in the treatment of cancer, as it allows for highly effective therapeutic results through image-guided phototherapy. Porphyrins have attracted significant interest in the treatment and diagnosis of cancer due to their excellent phototherapeutic effects in phototherapy and their remarkable imaging capabilities in fluorescence imaging, magnetic resonance imaging and photoacoustic imaging. However, porphyrins suffer from poor water solubility, low near-infrared absorption and insufficient tumor accumulation. The development of nanotechnology provides an effective way to improve the bioavailability, phototherapeutic effect and imaging capability of porphyrins. This review highlights the research results of porphyrin-based small molecule nanoparticles in phototherapy and image-guided phototherapy in the last decade and discusses the challenges and directions for the development of porphyrin-based small molecule nanoparticles in phototherapy.

Polymer-Based Hybrid Nanoarchitectures for Cancer Therapy Applications

Globally, cancer is affecting societies and is becoming an important cause of death. Chemotherapy can be highly effective, but it is associated with certain problems, such as undesired targeting and multidrug resistance. The other advanced therapies, such as gene therapy and peptide therapy, do not prove to be effective without a proper delivery medium. Polymer-based hybrid nanoarchitectures have enormous potential in drug delivery. The polymers used in these nanohybrids (NHs) provide them with their distinct properties and also enable the controlled release of the drugs. This review features the recent use of polymers in the preparation of different nanohybrids for cancer therapy published since 2015 in some reputed journals. The polymeric nanohybrids provide an advantage in drug delivery with the controlled and targeted delivery of a payload and the irradiation of cancer by chemotherapeutical and photodynamic therapy.

Self-assembled Cupric Oxide Nanoclusters for Highly efficient chemodynamic therapy

Chemodynamic therapy (CDT) based on Fenton and Fenton-like reactions induces cancer cell killing via in situ catalyzing H₂ O₂ and generating highly oxidative hydroxyl radicals (⋅OH) in tumor sites. Their application is not limited by tumor grown depth or hypoxic microenvironment. However, the reaction efficiency is still hampered due to the structure of catalytic agents and the requirement for low pH environment. Here, we design a porous CuO nanocluster (CuO NC) through self-assembly of oleylamine stabilized CuO NPs (OAm-CuO NPs), and functionalize it with folic acid (CuO NC-FA) for specific tumor cell targeting. It can catalyze H₂ O₂ with high efficiency in nearly neutral environment. Besides, the porous structure of CuO NC also helps the diffusion of H₂ O₂ to the interior of nanocluster to further improve Fenton-like reaction efficiency. The convenient synthesis of CuO NC-FA with good Fenton-like reaction efficiency at neutral environment demonstrates good chemodynamic therapy effect.

Nrf2 signaling pathway in trace metal carcinogenesis: A cross-talk between oxidative stress and angiogenesis

A large number of people worldwide are affected by chronic metal exposure, which is known to be associated with different type of malignancies. The mechanisms of metal carcinogenicity are complex in nature, and excessive reactive oxygen species (ROS) generation induced by chronic metal exposure, among the other factors, has been proposed as one of the major mechanisms involved in that process. In tumor cells, ROS buildup may lead to cell death through intrinsic and extrinsic signaling pathways. Furthermore, ROS-mediated redox signaling has a crucial role in angiogenesis, which is recognized as an essential step in tumor progression. There are several redox-modulating pathways and among them, the nuclear factor erythroid2-related factor2 (Nrf2), as a sensor of oxidative or electrophilic stress, has introduced as a master regulator of cellular response against environmental stresses. Activation of Nrf2 signaling induces expression of wide variety of antioxidant and detoxification enzymes genes. Thus, this transcription factor has recently received much attention as a target for cancer chemoprevention. But meanwhile, constitutive Nrf2 activation in cancerous cells may promote cancer progression and resistance to chemotherapy. The current review describes the major underlying mechanisms involved in carcinogenesis of trace metals: copper, silver, and cadmium, with a special focus on the Nrf2 signaling pathway as a crossroad between oxidative stress and angiogenesis.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

F,N-Doped carbon dots as efficient Type I photosensitizers for photodynamic therapy

Photodynamic therapy (PDT) is a promising and emerging method for the treatment of cancer. Usually, Type II PDT is used in the clinic, and mainly involves three key elements: a photosensitizer, molecular oxygen and laser light. However, it is known that tumor tissue is deficient in oxygen molecules which is why Type I PDT is mostly preferred in the therapy of tumors in which the hypoxic tissue plays a major role. Fluorescent carbon dots (CDs) have shown great potential in cancer theranostics, acting as bioimaging agents and photosensitizers. Herein, we have synthesized novel kinds of fluorine and nitrogen co-doped carbon dots (F,NCDs) that emit bright green fluorescence under ultra-violet light. The F,NCDs have excellent water solubility and low cytotoxicity. They can generate hydroxyl radicals (˙OH) and superoxide anions (˙O2-) under LED light (400-500 nm, 15 mW cm-2) irradiation, making them ideal photosensitizers for Type I PDT. Furthermore, upon using the HepG2 cell line as an in vitro model, the F,NCDs exhibit a better cell imaging effect and higher PDT efficiency than the control sample of CDs without F and N doping. This work has illustrated that the F,NCDs are promising in achieving the image-guided PDT of cancers, usually in a hypoxia tumor microenvironment.

Study of copper-cysteamine based X-ray induced photodynamic therapy and its effects on cancer cell proliferation and migration in a clinical mimic setting

Copper-cysteamine as a new generation of sensitizers can be activated by light, X-rays, microwaves, or ultrasound to produce reactive oxygen species. X-ray induced photodynamic therapy (X-PDT) has been studied extensively; however, most of the studies reported so far were conducted in the laboratory, which is not conducive to the clinical translation conditions. In this contribution, for the first time, we investigated the treatment efficiency of copper-cysteamine (Cu-Cy) based X-PDT by mimicking the clinical conditions with a clinical linear accelerator and building deep-seated tumor models to study not only the effectiveness but also its effects on the cell migration and proliferation in the level of the cell, tissue, and animal. The results showed that, without X-ray irradiation, Cu-Cy nanoparticles (NPs) had a low toxicity in HepG2, SK-HEP-1, Li-7, and 4T1 cells at a concentration below 100 mg/L. Interestingly, for the first time, it was observed that Cu-Cy mediated X-PDT can inhibit the proliferation and migration of these cell lines in a dose-dependent manner. Antigen markers of migration and cell proliferation, proliferating cell nuclear antigen (PCNA) and E-cadherin, from tumor tissue in the X-PDT group were remarkably different from that of the control group. Furthermore, the MRI assessment showed that the Cu-Cy based X-PDT inhibited the growth of deeply located tumors in mice and rabbits (p < 0.05) without any obvious toxicities in vivo. Overall, these new findings demonstrate that Cu-Cy NPs have a safe and promising clinical application prospect in X-PDT to improve the efficiency of radiotherapy (RT) for deep-seated tumors and effectively inhibit tumor cell proliferation and migration.

Aggregation-induced emission luminogens for highly effective microwave dynamic therapy

Aggregation-induced emission luminogens (AIEgens) exhibit efficient cytotoxic reactive oxygen species (ROS) generation capability and unique light-up features in the aggregated state, which have been well explored in image-guided photodynamic therapy (PDT). However, the limited penetration depth of light in tissue severely hinders AIEgens as a candidate for primary or adjunctive therapy for clinical applications. Coincidentally, microwaves (MWs) show a distinct advantage for deeper penetration depth in tissues than light. Herein, for the first time, we report AIEgen-mediated microwave dynamic therapy (MWDT) for cancer treatment. We found that two AIEgens (TPEPy-I and TPEPy-PF6) served as a new type of microwave (MW) sensitizers to produce ROS, including singlet oxygen (1O2), resulting in efficient destructions of cancer cells. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and live/dead assays reveal that the two AIEgens when activated by MW irradiation can effectively kill cancer cells with average IC-50 values of 2.73 and 3.22 μM, respectively. Overall, the ability of the two AIEgens to be activated by MW not only overcomes the limitations of conventional PDT, but also helps to improve existing MW ablation therapy by reducing the MW dose required to achieve the same therapeutic outcome, thus reducing the occurrence of side-effects of MW radiation.

Recent advances and trends in nanoparticles based photothermal and photodynamic therapy

Light-mediated therapies, including photodynamic therapy (PDT) and photothermal therapy (PTT) have been exploited as minimally invasive techniques for ablation of various tumors., Both modalities may eradicate tumors with minimal side effects to normal tissues and organs. Moreover, developments of light-mediated approaches using nanoparticles (NPs) and photosensitizer (PS) as diagnostic and therapeutic agents may have a crucial role in achieving successful cancer treatment. In recent years, novel nanoplatforms and strategies have been investigated to boost the therapeutic effect.. In this regard, gold, iron oxide, graphene oxide nanoparticles and hybrid nanocomposites have attracted attention.. Moreover, the combination of these materials with PS, in the form of hybrid NPs, reduces in vitro and in vivo normal tissue cytotoxicity, improves their solubility property in the biological environment and enhances the therapeutic effects. In this review, we look into the basic principles of PTT and PDT with their strengths and limitations to treat cancers. We also will discuss light-based nanoparticles and their PTT and PDT applications in the preclinical and clinical translation. Also, recent advances and trends in this field will be discussed along with the clinical challenges of PTT and PDT.

Recent Advances of Upconversion Nanomaterials in the Biological Field

Rare Earth Upconversion nanoparticles (UCNPs) are a type of material that emits high-energy photons by absorbing two or more low-energy photons caused by the anti-stokes process. It can emit ultraviolet (UV) visible light or near-infrared (NIR) luminescence upon NIR light excitation. Due to its excellent physical and chemical properties, including exceptional optical stability, narrow emission band, enormous Anti-Stokes spectral shift, high light penetration in biological tissues, long luminescent lifetime, and a high signal-to-noise ratio, it shows a prodigious application potential for bio-imaging and photodynamic therapy. This paper will briefly introduce the physical mechanism of upconversion luminescence (UCL) and focus on their research progress and achievements in bio-imaging, bio-detection, and photodynamic therapy.

Recent progress in sono-photodynamic cancer therapy: From developed new sensitizers to nanotechnology-based efficacy-enhancing strategies

Many sensitizers have not only photodynamic effects, but also sonodynamic effects. Therefore, the combination of sonodynamic therapy (SDT) and photodynamic therapy (PDT) using sensitizers for sono-photodynamic therapy (SPDT) provides alternative opportunities for clinical cancer therapy. Although significant advances have been made in synthesizing new sensitizers for SPDT, few of them are successfully applied in clinical settings. The anti-tumor effects of the sensitizers are restricted by the lack of tumor-targeting specificity, incapability in deep intratumoral delivery, and the deteriorating tumor microenvironment. The application of nanotechnology-based drug delivery systems (NDDSs) can solve the above shortcomings, thereby improving the SPDT efficacy. This review summarizes various sensitizers as sono/photosensitizers that can be further used in SPDT, and describes different strategies for enhancing tumor treatment by NDDSs, such as overcoming biological barriers, improving tumor-targeted delivery and intratumoral delivery, providing stimuli-responsive controlled-release characteristics, stimulating anti-tumor immunity, increasing oxygen supply, employing different therapeutic modalities, and combining diagnosis and treatment. The challenges and prospects for further development of intelligent sensitizers and translational NDDSs for SPDT are also discussed.

Advances in chlorin-based photodynamic therapy with nanoparticle delivery system for cancer treatment

Introduction: The treatment of tumors is one of the most difficult problems in the medical field at present. Patients often use a comprehensive therapy that combines surgery, radiotherapy, and chemotherapy. Photodynamic therapy (PDT) has prominent potential for eradicating various cancers. Chlorin-based photosensitizers (PSs), as one of the most utilized photosensitizers, have many advantages over conventional photosensitizers; however, a successful chlorin-based PDT needs multi-functional nano-carriers for selective photosensitizer delivery. The number of researches about nanoparticles designed for improved chlorin-based PSs is increasing in the current era. In this article, we give a brief review focused on the recent research progress in design of chlorin-based nanoparticles for the treatment of malignant tumors with photodynamic therapy.Areas covered: This review focuses on the current nanoparticle platforms for PDT, and describes different strategies to achieve controllable PDT by chlorin-nano-delivery systems. The challenges and prospects of PDT in clinical applications are also discussed.Expert opinions: The requirement for PDT to eradicate cancers has increased exponentially in recent years. The major clinically used photosensitizers are hydrophobic. The main obstacles in effective delivery of PSs are associated with this intrinsic nature. The design of nano-delivery systems to load PSs is pivotal for PSs' widespread use.

Organic/inorganic nanohybrids rejuvenate photodynamic cancer therapy

The development of nanotechnology has changed the 100-year-old paradigm of photodynamic therapy (PDT), in which organic/inorganic hybrid nanomaterials have made great contributions. In this review, we first describe the mechanisms of PDT and discuss the limitations of conventional PDT. On this basis, we summarize recent progress in organic/inorganic nanohybrids-based photodynamic agents, highlighting how these nanohybrids can be programmed to overcome challenges in photodynamic cancer therapy.

Emerging hybrid biomaterials for oxidative stress induced photodynamic therapy

Cancer therapy has undergone tremendous advancements in the past few years. The drawbacks of most of these therapies have encouraged researchers to obtain further insight into the complex chemical, biochemical and biological processes ongoing in the evolving cancer cells. These studies have led to an advent of reactive oxygen species mediated therapies to target and disrupt the cancer pathology. Photodynamic therapy (PDT) has emerged as a potent candidate for oxidative stress mediated non-invasive technique for rapid diagnosis and treatment of cancer. Towards this, biomacromolecules derived hybrid nanomaterials have contributed largely in the development of various therapeutics and theranostics for efficacious cancer management that can assist PDT. This review summarizes various hybrid biomaterials and advanced techniques that have been explored widely in the past few years for PDT application. The article also mentions some of the important in-vitro and in-vivo developments and observations explored by employing these materials for PDT application. The article also describes the interactions of these materials at the biological interface and the probable mechanism that assist in generation of oxidative stress and subsequent cell death.

Copper-Based Nanoscale Coordination Polymers Augmented Tumor Radioimmunotherapy for Immunogenic Cell Death Induction and T-Cell Infiltration

Insufficient T-cell infiltration seriously hinders the efficacy of tumor immunotherapy. Induction of immunogenic cell death (ICD) is a potentially feasible approach to increase T-cell infiltration. Since ionizing radiation can only induce low-level ICD, this study constructs Cu-based nanoscale coordination polymers (Cu-NCPs) with mixed-valence (Cu⁺ /Cu²⁺ ), which can simultaneously and independently induce the generation of Cu⁺ -triggered hydroxyl radicals and Cu²⁺ -triggered GSH elimination, to synergize with radiation therapy for potent ICD induction. Markedly, this synergetic therapy remarkably enhances dendritic cell maturation and promotes antitumor CD8⁺ T-cell infiltration, thereby potentiating the development of checkpoint blockade immunotherapies against primary and metastatic tumors.

Interaction of Genetically Encoded Photosensitizers with Scintillating Nanoparticles for X-ray Activated Photodynamic Therapy

Photodynamic therapy (PDT) applications are limited by the low penetration of UV-visible light into biological tissues. Considering X-rays as an alternative to excite photosensitizers (PS) in a deeper tumor, an intermediate particle able to convert the X-ray energy into visible light (scintillating nanoparticle, ScNP) is necessary. Moreover, accumulation of PS in the target cells is also required. Genetically encoded proteins could be used as a photosensitizer, allowing the exclusive expression of PS inside the tumor cells. Here, the interaction of eGFP, KillerOrange, and KillerRed proteins with LaF₃:Tb³⁺ ScNP was investigated, for the first time, in terms of its physicochemical and energy transfer properties. The protein structure, stability, and function were evaluated upon adverse physiological conditions and X-ray irradiation. Optimal parameters for energy transfer from ScNP to the proteins were investigated, paving the way for the use of genetically encoded photosensitizers for applications in X-ray activated photodynamic therapy.

Nanomaterials for Airborne Virus Inactivation: A Short Review

The coronavirus disease 2019 (COVID-19) that broke out at the end of 2019 spread rapidly around the world, causing a large number of deaths and serious economic losses. Previous studies showed that aerosol transmission is one of the main pathways for the spread of COVID-19, Therefore, effective control measures are urgently needed to contain the epidemic. Nanomaterials have broad-spectrum antiviral capabilities, and their inactivation for viruses in the air has been extensively studied. This review discusses antiviral nanomaterials such as metal nanomaterials, metal oxide-based nano-photocatalysts, and nonmetallic nanomaterials; summarizes their structure and chemical properties, the efficiency of inactivating viruses, the mechanism of inactivating viruses, and the application of virus purification in the air. This review provides insights on the development and application of antiviral nanomaterials, which can help control the aerosol transmission of viruses.

Fabrication of Anisotropic Cu Ferrite-Polymer Core-Shell Nanoparticles for Photodynamic Ablation of Cervical Cancer Cells

In this work we developed methylene blue-immobilized copper-iron nanoparticles (MB-CuFe NPs) through a facile one-step hydrothermal reaction to achieve a better phototherapeutic effect. The Fe/Cu ratio of the CuFe NPs was controllable by merely changing the loading amount of iron precursor concentration. The CuFe NPs could serve as a Fenton catalyst to convert hydrogen peroxide (H2O2) into reactive oxygen species (ROS), while the superparamagnetic properties also suggest magnetic resonance imaging (MRI) potential. Furthermore, the Food and Drug Administration (FDA)-approved MB photosensitizer could strongly adsorb onto the surface of CuFe NPs to facilitate the drug delivery into cells and improve the photodynamic therapy at 660 nm via significant generation of singlet oxygen species, leading to enhanced cancer cell-damaging efficacy. An MTT (thiazolyl blue tetrazolium bromide) assay proved the low cytotoxicity of the CuFe NPs to cervical cancer cells (HeLa cells), namely above 80% at 25 ppm of the sample dose. A slight dissolution of Cu and Fe ions from the CuFe NPs in an acidic environment was obtained, providing direct evidence for CuFe NPs being degradable without the risk of long-term retention in the body. Moreover, the tremendous photo-to-thermal conversion of CuFe NPs was examined, which might be combined with photodynamic therapy (PDT) for promising development in the depletion of cancer cells after a single pulse of deep-red light irradiation at high laser power.

Combination of Disulfiram and Copper-Cysteamine Nanoparticles for an Enhanced Antitumor Effect on Esophageal Cancer

Esophageal cancer (EC) is the sixth leading cause of cancer deaths worldwide with a low 5-year survival rate. More effective chemotherapeutic drugs, either new or repurposing ones, are urgently needed. Disulfiram (DSF) is a safe and public domain drug for alcohol addiction treatment and later shown to have anti-cancer capability, especially when administrated together with copper. The present study is to test the hypothesis that a newly developed copper-cysteamine (Cu-Cy) nanoparticles (NPs) can enhance the anti-tumor effect of DSF on esophageal cancer with reduced risk of copper poisoning. Our results showed that Cu-Cy NPs could greatly facilitate DSF to inhibit cell proliferation in cultured human esophageal cancer cells. Interestingly, the combined inhibitory function could be further enhanced when DSF and Cu-Cy NPs were present at an optimal molar ratio of 1:4. The results of the change in physical color, UV-vis absorption and fluorescence spectra, X-ray diffraction patterns, and FTIR spectra from a mixture of DSF and Cu-Cy NPs suggest a possible reaction between DSF and Cu-Cy NPs and the formation of new materials. Furthermore, cellular mechanistic studies revealed that the combination of DSF and Cu-Cy NPs resulted in reactive oxygen species (ROS) accumulation, and blocked nuclear translocation of NF-ƙB (p65) in esophageal cancer cells. Moreover, in xenograft nude mice, combined administration of DSF and Cu-Cy NPs greatly inhibited tumor growth without noticeable histological toxicity, while any single agent at the same doses presented no inhibitory function. Together, this study demonstrates an effective anti-cancer function of combined treatment of DSF and Cu-Cy NPs in vitro and in vivo, which could be a promising new chemotherapy for esophageal cancer patients.

Effects of Nanoparticle Size and Radiation Energy on Copper-Cysteamine Nanoparticles for X-ray Induced Photodynamic Therapy

The Copper-cysteamine (Cu-Cy) nanoparticle is a novel sensitizer with a potential to increase the effectiveness of radiation therapy for cancer treatment. In this work, the effect of nanoparticle size and the energy of X-rays on the effectiveness of radiation therapy are investigated. The effect of the particle size on their performance is very complicated. The nanoparticles with an average size of 300 nm have the most intense photoluminescence, the nanoparticles with the average size of 100 nm have the most reactive oxygen species production upon X-ray irradiation, while the nanoparticles with the average size of 40 nm have the best outcome in the tumor suppression in mice upon X-ray irradiation. For energy, 90 kVp radiation resulted in smaller tumor sizes than 250 kVp or 350 kVp radiation energies. Overall, knowledge of the effect of nanoparticle size and radiation energy on radiation therapy outcomes could be useful for future applications of Cu-Cy nanoparticles.

Copper-Doped Nanoscale Covalent Organic Polymer for Augmented Photo/Chemodynamic Synergistic Therapy and Immunotherapy

Due to the specific tumor microenvironment (TME) and immunosuppressive state of cancer cells, conventional antitumor therapies face severe challenges, such as high rates of recurrence and metastasis. Herein, Cu-PPT nanoparticles were synthesized based on copper acetate, p-phenylenediamine, and 5,10,15,20-tetra-(4-aminophenyl)porphyrin via oxidative coupling reaction for the first time, and the resultant product was used for synergistic photothermal therapy (PTT), photodynamic therapy (PDT), and chemodynamic therapy (CDT). The polymer nanoparticles exhibited excellent photodynamic and photothermal effect with a photothermal conversion efficacy of 40.1% under 650 and 808 nm laser irradiation, respectively. Encapsulated Cu(I)/Cu(II) ions permitted Cu-PPT with glutathione (GSH) peroxidase-mimicking, catalase-mimicking, and Fenton-like activity to regulate TME. Depletion of overexpressed GSH would reduce antioxidant capacity, generated O₂ could relieve hypoxia for enhancing PDT, and hyperthermia from PTT could promote the yield of ·OH. This multifunctional nanosystem with cascade reactions could inhibit tumor growth and activate immune responses effectively. By further combining with antiprogrammed death-ligand 1 (anti-PD-L1) checkpoint blockade therapy, distant tumor growth and cancer metastasis were successfully suppressed.

A powerful combination of copper-cysteamine nanoparticles with potassium iodide for bacterial destruction

Herein, for the first time, we demonstrate that the combination of copper-cysteamine (Cu-Cy) nanoparticles (NPs) and potassium iodide (KI) can significantly inactivate both Gram-positive MRSA and Gram-negative E. coli. To uncover the mystery of the killing, the interaction of KI with Cu-Cy NPs was investigated systematically and the products from their interaction were identified. No copper ions were released after adding KI to Cu-Cy NPs in cell-free medium and, therefore, it is reasonable to conclude that the Fenton reaction induced by copper ions is not responsible for the bacterial killing. Based on the observations, we propose that the major killing mechanism involves the generation of toxic species, such as hydrogen peroxide, triiodide ions, iodide ions, singlet oxygen, and iodine molecules. Overall, the powerful combination of Cu-Cy NPs and KI has good potential as an independent treatment or a complementary antibiotic treatment to infectious diseases.

Analysis of autophagy-related genes and associated noncoding RNAs and transcription factors in digestive system tumors

Aim: To investigate the autophagy-related gene (ATG) expression and the associated noncoding RNAs (ncRNA) and transcription factors (TF) in digestive system tumors (DST). Methods: We systematically investigated the ATG expression in DST by weighted gene correlation network analysis, crosstalk connection, functional analysis and Pivot analysis. Results: ATGs were clustered into six modules with co-expression in DST. Functional analysis revealed that six ATG-related modules were enriched in biological pathways involved in tumorigenesis. Pivot analysis identified key ncRNAs and TFs, which are essential for the pathogenesis, clinical diagnosis and treatment of DST. Conclusion: Our study highlights the crucial roles of ncRNA and TFs in the identification of potential biomarkers or therapeutic targets for DST.