Radionuclide Imaging-Guided Chemo-Radioisotope Synergistic Therapy Using a 131I-Labeled Polydopamine Multifunctional Nanocarrier

Sanguinarine Induces Necroptosis of HCC by Targeting PKM2 Mediated Energy Metabolism

BACKGROUNDS

Abnormal metabolism is the hallmark of hepatocellular carcinoma. Targeting energy metabolism has become the major focus of cancer therapy. The natural product, sanguinarine, displays remarkable anti-tumor properties by disturbing energy homeostasis; however, the underlying mechanism has not yet been elucidated.

METHODS

The anticancer activity of sanguinarine was determined using CCK-8 and colony formation assay. Morphological changes of induced cell death were observed under electron microscopy. Necroptosis and apoptosis related markers were detected using western blotting. PKM2 was identified as the target by transcriptome sequencing. Molecular docking assay was used to evaluate the binding affinity of sanguinarine to the PKM2 molecule. Furthermore, Alb-CreERT2; PKM2loxp/loxp; Rosa26RFP mice was used to construct the model of HCC-through the intervention of sanguinarine in vitro and in vivo-to accurately explore the regulation effect of sanguinarine on cancer energy metabolism.

RESULTS

Sanguinarine inhibited tumor proliferation, metastasis and induced two modes of cell death. Molecular docking of sanguinarine with PKM2 showed appreciable binding affinity. PKM2 kinase activity and aerobic glycolysis rate declined, and mitochondrial oxidative phosphorylation was inhibited by sanguinarine application; these changes result in energy deficits and lead to necroptosis. Additionally, sanguinarine treatment prevents the translocation of PKM2 into the nucleus and suppresses the interaction of PKM2 with β-catenin; the transcriptional activity of PKM2/β-catenin signaling and its downstream genes were decreased.

CONCLUSIONS

Sanguinarine showed remarkable anti-HCC activity via regulating energy metabolism by PKM2/β-catenin signaling. On the basis of these investigations, we propose that sanguinarine might be considered as a promising compound for discovery of anti-HCC drugs.

Radioiodine-131-Labeled Theranostic Nanoparticles for Transarterial Radioembolization and Chemoembolization Combination Therapy of VX2 Liver Tumor

In interventional treatment, materials are administered into the blood supply artery and directly delivered to tumors, offering proper scenarios for nanomedicine potential clinical applications. Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are effective treatment methods for hepatocellular carcinoma (HCC), but postoperative residual tumor may result in intrahepatic recurrence and distant metastasis. The combination therapy of TACE and TARE based on multifunctional nanoparticles (NPs) is expected to overcome the drug resistance in hypoxic tumors and improve the therapeutic effect. Herein, BaGdF5 NPs are synthesized and then coated with polydopamine (PDA), conjugated with the chemotherapeutic drug cis-diamminedichloride platinum (CDDP), radio-labeled with therapeutic radionuclide 131 I, yielding 131 I-BaGdF5 @PDA-CDDP NPs. The in vitro anti-cancer effects of 131 I-BaGdF5 @PDA-CDDP NPs are confirmed using CCK-8 and γ-H2AX assays in Huh7 cells. Mixed with Lipiodol, 131 I-BaGdF5 @PDA-CDDP NPs are injected into the hepatic artery via a microcatheter to realize the TACE and TARE combination therapy in a rabbit VX2 liver tumor model. The results indicate that glucose metabolism is clearly decreased based on 18 F-FDG PET imaging and the apoptosis of tumor cells is increased. Furthermore, 131 I and BaGdF5 NPs can be used for SPECT imaging and CT/MR imaging respectively, facilitating real-time monitoring of the in vivo biodistribution of 131 I-BaGdF5 @PDA-CDDP NPs.

Recent advances of polymeric nanoplatforms for cancer treatment: smart delivery systems (SDS), nanotheranostics and multidrug resistance (MDR) inhibition

Nanotheranostics is a promising field that combines the benefits of diagnostic and treatment into a single nano-platform that not only administers treatment but also allows for real-time monitoring of therapeutic response, decreasing the possibility of under/over-drug dosing. Furthermore, developing smart delivery systems (SDSs) for cancer theranostics that can take advantage of various tumour microenvironment (TME) conditions (such as deformed tumour vasculature, various over-expressed receptor proteins, reduced pH, oxidative stress, and resulting elevated glutathione levels) can aid in achieving improved pharmacokinetics, higher tumour accumulation, enhanced antitumour efficacy, and/or decreased side effects and multidrug resistance (MDR) inhibition. Polymeric nanoparticles (PNPs) are being widely investigated in this regard due to their unique features such as small size, passive/active targeting possibility, better pharmaceutical kinetics and biological distribution, decreased adverse reactions of the established drugs, inherent inhibitory properties to MDR efflux pump proteins, as well as the feasibility of delivering numerous therapeutic substances in just one design. Hence in this review, we have primarily discussed PNPs based targeted and/or controlled SDSs in which we have elaborated upon different TME mediated nanotheranostic platforms (NTPs) including active/passive/magnetic targeting platforms along with pH/ROS/redox-responsive platforms. Besides, we have elucidated different imaging guided cancer therapeutic platforms based on four major cancer imaging techniques i.e., fluorescence/photo-acoustic/radionuclide/magnetic resonance imaging, Furthermore, we have deliberated some of the most recently developed PNPs based multimodal NTPs (by combining two or more imaging or therapy techniques on a single nanoplatform) in cancer theranostics. Moreover, we have provided a brief update on PNPs based NTP which are recently developed to overcome MDR for effective cancer treatment. Additionally, we have briefly discussed about the tissue biodistribution/tumour targeting efficiency of these nanoplatforms along with recent preclinical/clinical studies. Finally, we have elaborated on various limitations associated with PNPs based nanoplatforms.

Polymer composite microspheres loading 177Lu radionuclide for interventional radioembolization therapy and real-time SPECT imaging of hepatic cancer

BACKGROUND

Transarterial radioembolization (TARE) with 90Y-labeled glass and resin microspheres is one of the primary treatment strategies for advanced-stage primary and metastatic hepatocellular carcinoma (HCC). However, difficulties of real-time monitoring post administration and embolic hypoxia influence treatment prognosis. In this study, we developed a new biodegradable polymer microsphere that can simultaneously load 177Lu and MgO nanoparticle, and evaluated the TARE therapeutic efficacy and biosafety of 177Lu-PDA-CS-MgO microspheres for HCC treatment.

METHODS

Chitosan microspheres were synthesized through emulsification crosslink reaction and then conducted surface modification with polydopamine (PDA). The 177Lu and nano MgO were conjugated to microspheres using active chemical groups of PDA. The characteristics of radionuclide loading efficiency, biodegradability, blood compatibility, and anti-tumor effectwere evaluated both in vitro and in vivo. SPECT/CT imaging was performed to monitor bio-distribution and bio-stability of 177Lu-PDA-CS-MgO after TARE treatment. The survival duration of each rat was monitored. HE analysis, TUNEL analysis, immunohistochemical analysis, and western blot analysis were conducted to explore the anti-tumor effect and mechanism of composited microspheres. Body weight, liver function, blood routine examination were monitored at different time points to evaluate the bio-safety of microspheres.

RESULTS

The composite 177Lu-PDA-CS-MgO microsphere indicated satisfactory degradability, biocompatibility, radionuclide loading efficiency and radiochemical stability in vitro. Cellular evaluation showed that 177Lu-PDA-CS-MgO had significant anti-tumor effect and blocked tumor cell cycles in S phase. Surgical TARE treatment with 177Lu-PDA-CS-MgO significantly prolonged the medial survival time from 49 d to 105 d, and effectively inhibited primary tumor growth and small metastases spreading. Moreover, these microspheres indicated ideal in vivo stability and allowed real-time SPECT/CT monitoring for up to 8 weeks. Immunostaining and immunoblotting results also confirmed that 177Lu-PDA-CS-MgO had potential in suppressing tumor invasion and angiogenesis, and improved embolic hypoxia in HCC tissues. Further evaluations of body weight, blood test, and pathological analysis indicated good biosafety of 177Lu-PDA-CS-MgO microspheres in vivo.

CONCLUSION

Our study demonstrated that 177Lu-PDA-CS-MgO microsphere hold great potential as interventional brachytherapy candidate for HCC therapy. Polymer composite microspheres loading 177Lu radionuclide and MgO nanoparticles for interventional radioembolization therapy and real-time SPECT imaging of hepatic cancer.

Polyphenol-Based Nanosystems for Next-Generation Cancer Therapy: Multifunctionality, Design, and Challenges

With the continuous updating of cancer treatment methods and the rapid development of precision medicine in recent years, there are higher demands for advanced and versatile drug delivery systems. Scientists are committed to create greener and more effective nanomedicines where the carrier is no longer limited to a single function of drug delivery. Polyphenols, which can act as both active ingredients and fundamental building blocks, are being explored as potential multifunctional carriers that are efficient and safe for design purposes. Due to their intrinsic anticancer activity, phenolic compounds have shown surprising expressiveness in ablation of tumor cells, overcoming cancer multidrug resistance (MDR), and enhancing immunotherapeutic efficacy. This review provides an overview of recent advances in the design, synthesis, and application of versatile polyphenol-based nanosystems for cancer therapy in various modes. Moreover, the merits of polyphenols and the challenges for their clinical translation are also discussed, and it is pointed out that the novel polyphenol delivery system requires further optimization and validation.

Polydopamine-containing nano-systems for cancer multi-mode diagnoses and therapies: A review

Polydopamine (PDA) has fascinating properties such as inherent biocompatibility, simple preparation, strong near-infrared absorption, high photothermal conversion efficiency, and strong metal ion chelation, which have catalyzed extensive research in PDA-containing multifunctional nano-systems particularly for biomedical applications. Thus, it is imperative to overview synthetic strategies of various PDA-containing nanoparticles (NPs) for state-of-the-art cancer multi-mode diagnoses and therapies applications, and offer a timely and comprehensive summary. In this review, we will focus on the synthetic approaches of PDA NPs, and summarize the construction strategies of PDA-containing NPs with different structure forms. Additionally, the application of PDA-containing NPs in bioimaging such as photoacoustic imaging, fluorescence imaging, magnetic resonance imaging and other imaging modalities will be reviewed. We will especially offer an overview of their therapeutic applications in tumor chemotherapy, photothermal therapy, photodynamic therapy, photocatalytic therapy, sonodynamic therapy, radionuclide therapy, gene therapy, immunotherapy and combination therapy. At the end, the current trends, limitations and future prospects of PDA-containing nano-systems will be discussed. This review aims to provide guidelines for new scientists in the field of how to design PDA-containing NPs and what has been achieved in this area, while offering comprehensive insights into the potential of PDA-containing nano-systems used in cancer diagnosis and treatment.

Melanin nanoparticles alleviate sepsis-induced myocardial injury by suppressing ferroptosis and inflammation

Myocardial injury as one of the severe complications leads to the increasing morbidity and mortality in patients with sepsis. Recent studies reported that reactive oxygen species (ROS)-mediated ferroptosis plays a critical role in the development of heart diseases. Therefore, we hypothesized that anti-ferroptosis agent might be a novel potential therapeutic strategy for sepsis-induced cardiac injury. Herein, we demonstrated that a small biocompatible and MRI-visible melanin nanoparticles (MMPP) improves myocardial function by inhibiting ROS-related ferroptosis signaling pathway. In LPS-induced murine sepsis model, after a single dose intravenously injection of MMPP treatment, MMPP markedly alleviated the myocardial injury including cardiac function and heart structure disorder through suppressing iron-accumulation induced ferroptosis. In vitro, MMPP inhibited cardiomyocyte death by attenuating oxidative stress, inflammation and maintaining mitochondrial homeostasis. Collectively, our findings demonstrated that MMPP protected heart against sepsis-induced myocardial injury via inhibiting ferroptosis and inflammation, which might be a novel therapeutic approach in future.

Methods for Radiolabelling Nanoparticles: SPECT Use (Part 1)

The use of nanoparticles (NPs) is rapidly increasing in nuclear medicine (NM) for diagnostic and therapeutic purposes. Their wide use is due to their chemical–physical characteristics and possibility to deliver several molecules. NPs can be synthetised by organic and/or inorganic materials and they can have different size, shape, chemical composition, and charge. These factors influence their biodistribution, clearance, and targeting ability in vivo. NPs can be designed to encapsulate inside the core or bind to the surface several molecules, including radionuclides, for different clinical applications. Either diagnostic or therapeutic radioactive NPs can be synthetised, making a so-called theragnostic tool. To date, there are several methods for radiolabelling NPs that vary depending on both the physical and chemical properties of the NPs and on the isotope used. In this review, we analysed and compared different methods for radiolabelling NPs for single-photon emission computed tomography (SPECT) use.

Assessment of Oxaliplatin-Loaded Iodine Nanoparticles for Chemoradiotherapy of Human Colorectal Cancer (HT-29) Cells

Colorectal cancer is highly prevalent worldwide and has significant morbidity and mortality in humans. High-atomic-number nanoparticles such as iodine can act as X-rays absorbers to increase the local dose. The synthesis and fabrication of oxaliplatin-loaded iodine nanoparticles, their characterization, cell toxicity, radiosensitivity, cell apoptosis, and cell cycle assay in human colorectal cancer (HT-29) cells are investigated. Results show that the synthesis of a new iodine nanoparticle, polymerized triiodobenzene coated with chitosan and combined with oxaliplatin as a chemotherapeutic drug, performed well in vitro in an intracellular radiosensitizer as chemoradiotherapy agent in HT-29 cell lines. Findings also show that the INPs alone have no impact on cell cycle development and apoptosis. In contrast, oxaliplatin-loaded INPs along with 2 and 6 MV radiation doses produced more apoptosis. The interaction of INPs with mega-voltage photon energies is the cause of a major radiosensitization enhancement in comparison to radiation alone. Furthermore, results show that INPs may work as radiosensitization nanoprobe agents in the treatment of HT-29 cells due to their effect on increasing radiation dose absorption. Overall, iodine nanoparticles may be used in the treatment of colorectal cancers in clinical studies.

Polydopamine encapsulated new indocyanine green theranostic nanoparticles for enhanced photothermal therapy in cervical cancer HeLa cells

Photothermal therapy (PTT) has attracted extensive attention in cancer treatment due to its non-invasiveness, high efficiency, and repeatability in recent years. Photothermal agents (PTAs) are the key factor for PTT. Recently, although an increasing number of PTAs have been developed, there is still a great demand for optimized photothermal nanoparticles (NPs) with low toxicity, bio-safety and stability. Herein, new indocyanine green (IR820) with near-infrared (NIR:700–1,700 nm) fluorescence emission was selected as a photothermal agent (PTA). To enhance the PTT property, IR820 was encapsulated with another kind of PTA, polydopamine (PDA) under alkaline conditions. Furthermore, to improve the biocompatibility of the NPs, methoxy polyethylene glycol amine (mPEG-NH2) was modified via a Michael addition to form a novel kind of IR820@PDA@PEG NPs. After detailed characterization and analysis, the obtained IR820@PDA@PEG NPs showed a spherical shape with an average diameter of ∼159.6 nm. Meanwhile, the formed IR820@PDA@PEG NPs exhibited better photostability and lower cytotoxicity than free IR820 molecules. The photothermal performance of IR820@PDA@PEG NPs was further analyzed in vitro, and the temperature of IR820@PDA@PEG NPs (100 μg/ml) reached 54.8°C under 793 nm laser irradiation. Afterwards, the cellular uptake of IR820@PDA@PEG NPs was evaluated via confocal laser scanning fluorescence microscopic imaging. Then, PTT experiments on HeLa cells demonstrated that IR820@PDA@PEG NPs can hyperthermal ablate cancer cells (∼49.1%) under 793 nm laser irradiation. Therefore, IR820@PDA@PEG NPs would be a promising PTA for the treatment of cervical cancer HeLa cells.

Radionuclide 131I-labeled albumin-indocyanine green nanoparticles for synergistic combined radio-photothermal therapy of anaplastic thyroid cancer

Objectives

Anaplastic thyroid cancer (ATC) cells cannot retain the radionuclide iodine 131 (¹³¹I) for treatment due to the inability to uptake iodine. This study investigated the feasibility of combining radionuclides with photothermal agents in the diagnosis and treatment of ATC.

Methods

¹³¹I was labeled on human serum albumin (HSA) by the standard chloramine T method. ¹³¹I-HSA and indocyanine green (ICG) were non-covalently bound by a simple stirring to obtain ¹³¹I-HSA-ICG nanoparticles. Characterizations were performed in vitro. The cytotoxicity and imaging ability were investigated by cell/in vivo experiments. The radio-photothermal therapy efficacy of the nanoparticles was evaluated at the cellular and in vivo levels.

Results

The synthesized nanoparticles had a suitable size (25–45 nm) and objective biosafety. Under the irradiation of near-IR light, the photothermal conversion efficiency of the nanoparticles could reach 24.25%. In vivo fluorescence imaging and single-photon emission CT (SPECT)/CT imaging in small animals confirmed that I-HSA-ICG/¹³¹I-HSA-ICG nanoparticles could stay in tumor tissues for 4–6 days. Compared with other control groups, ¹³¹I-HSA-ICG nanoparticles had the most significant ablation effect on tumor cells under the irradiation of an 808-nm laser.

Conclusions

In summary, ¹³¹I-HSA-ICG nanoparticles could successfully perform dual-modality imaging and treatment of ATC, which provides a new direction for the future treatment of iodine-refractory thyroid cancer.

Melanin and Melanin-Functionalized Nanoparticles as Promising Tools in Cancer Research-A Review

Cancer poses an ongoing global challenge, despite the substantial progress made in the prevention, diagnosis, and treatment of the disease. The existing therapeutic methods remain limited by undesirable outcomes such as systemic toxicity and lack of specificity or long-term efficacy, although innovative alternatives are being continuously investigated. By offering a means for the targeted delivery of therapeutics, nanotechnology (NT) has emerged as a state-of-the-art solution for augmenting the efficiency of currently available cancer therapies while combating their drawbacks. Melanin, a polymeric pigment of natural origin that is widely spread among many living organisms, became a promising candidate for NT-based cancer treatment owing to its unique physicochemical properties (e.g., high biocompatibility, redox behavior, light absorption, chelating ability) and innate antioxidant, photoprotective, anti-inflammatory, and antitumor effects. The latest research on melanin and melanin-like nanoparticles has extended considerably on many fronts, allowing not only efficient cancer treatments via both traditional and modern methods, but also early disease detection and diagnosis. The current paper provides an updated insight into the applicability of melanin in cancer therapy as antitumor agent, molecular target, and delivery nanoplatform.

(cRGD)2 peptides modified nanoparticles increase tumor-targeting therapeutic effects by co-delivery of albendazole and iodine-131

Albendazole (ABZ), a clinical antiparasitic drug, has shown potential antitumor effects in various tumors. Herein, we prepared dimeric cRGD [(cRGD)2] modified human serum albumin (HSA) nanosystem to co-delivery of albendazole (ABZ) and iodine-131 (131I) for chemoradiotherapy of triple-negative breast cancer (TNBC). HSA@ABZ NPs were synthesized by the self-assembly method. 131I-(cRGD)2/HSA@ABZ NPs were fabricated through covalently binding HSA@ABZ NPs with (cRGD)2 peptides, followed by chloramine T direct labeling with 131I. In vitro therapeutic effects on TNBC (MDA-MB-231 and 4T1 cells) were determined using MTT assay, crystal violet assay, wound-healing assay and western blotting analysis. In vivo treatment was performed using 4T1-bearing mice, and the tumor-targeting efficacy was assessed by gamma imaging. The distribution of NPs was quantitatively analyzed by detecting the gamma counts in tumor and main organs. The nanoparticles possessed negative charge, moderate size and good polydispersity index. Dual responding to pH and redox, the in vitro release rate of ABZ was more than 80% in 72 h. In vitro, NPs inhibited the proliferation of TNBC cells in a concentration-dependent manner and decreased cell migration. Western blotting analysis showed that the NPs, as well as free ABZ, cell-dependently induced autophagy and apoptosis by restraining or promoting the expression of p-p38 and p-JNK MAPK. In vivo, gamma imaging exhibited an earlier and denser radioactivity accumulation in tumor of 131I-(cRGD)2/HSA@ABZ NPs compared to NPs free of (cRGD)2 conjugating. Furthermore, 131I-(cRGD)2/HSA@ABZ NPs significantly suppressed tumor growth by restraining proliferation and promoting apoptosis in vivo. Our study suggested that the nanoparticles we developed enhanced tumor-targeting of ABZ and increased antitumor effects by combination of chemotherapy and radiotherapy.

Advances of Nanomedicine in Radiotherapy

Radiotherapy (RT) remains one of the current main treatment strategies for many types of cancer. However, how to improve RT efficiency while reducing its side effects is still a large challenge to be overcome. Advancements in nanomedicine have provided many effective approaches for radiosensitization. Metal nanoparticles (NPs) such as platinum-based or hafnium-based NPs are proved to be ideal radiosensitizers because of their unique physicochemical properties and high X-ray absorption efficiency. With nanoparticles, such as liposomes, bovine serum albumin, and polymers, the radiosensitizing drugs can be promoted to reach the tumor sites, thereby enhancing anti-tumor responses. Nowadays, the combination of some NPs and RT have been applied to clinical treatment for many types of cancer, including breast cancer. Here, as well as reviewing recent studies on radiotherapy combined with inorganic, organic, and biomimetic nanomaterials for oncology, we analyzed the underlying mechanisms of NPs radiosensitization, which may contribute to exploring new directions for the clinical translation of nanoparticle-based radiosensitizers.

Imaging of Tumor Hypoxia With Radionuclide-Labeled Tracers for PET

The hypoxic state in a solid tumor refers to the internal hypoxic environment that appears as the tumor volume increases (the maximum radius exceeds 180-200 microns). This state can promote angiogenesis, destroy the balance of the cell’s internal environment, and lead to resistance to radiotherapy and chemotherapy, as well as poor prognostic factors such as metastasis and recurrence. Therefore, accurate quantification, mapping, and monitoring of hypoxia, targeted therapy, and improvement of tumor hypoxia are of great significance for tumor treatment and improving patient survival. Despite many years of development, PET-based hypoxia imaging is still the most widely used evaluation method. This article provides a comprehensive overview of tumor hypoxia imaging using radionuclide-labeled PET tracers. We introduced the mechanism of tumor hypoxia and the reasons leading to the poor prognosis, and more comprehensively included the past, recent and ongoing studies of PET radiotracers for tumor hypoxia imaging. At the same time, the advantages and disadvantages of mainstream methods for detecting tumor hypoxia are summarized.

Utilization of nanotechnology in targeted radionuclide cancer therapy: monotherapy, combined therapy and radiosensitization

The rapid progress of nanomedicine field has a great influence on the different tumor therapeutic trends. It achieves a potential targeting of the therapeutic agent to the tumor site with neglectable exposure of the normal tissue. In nuclear medicine, nanocarriers have been employed for targeted delivery of therapeutic radioisotopes to the malignant tissues. This systemic radiotherapy is employed to overcome the external radiation therapy drawbacks. This review overviews studies concerned with investigation of different nanoparticles as promising carriers for targeted radiotherapy. It discusses the employment of different nanovehicles for achievement of the synergistic effect of targeted radiotherapy with other tumor therapeutic modalities such as hyperthermia and photodynamic therapy. Radiosensitization utilizing different nanosensitizer loaded nanoparticles has also been discussed briefly as one of the nanomedicine approach in radiotherapy.

Biomaterial-mediated internal radioisotope therapy

Radiation therapy (RT), including external beam radiotherapy (EBRT) and internal radioisotope therapy (RIT), has been an indispensable strategy for cancer therapy in clinical practice in recent years. Ionized atoms and free radicals emitted from the nucleus of radioisotopes can cleave a single strand of DNA, inducing the apoptosis of cancer cells. Thus far, nuclides used for RIT could be classified into three main types containing alpha (α), beta (β), and Auger particle emitters. In order to enhance the bioavailability and reduce the physiological toxicity of radioisotopes, various biomaterials have been utilized as multifunctional nanocarriers, including targeting molecules, macromolecular monoclonal antibodies, peptides, inorganic nanomaterials, and organic and polymeric nanomaterials. Therapeutic radioisotopes have been labeled onto these nanocarriers via different methods (chelating, chemical doping, encapsulating, displacement) to inhibit or kill cancer cells. With the continuous development of research in this respect, more promising biomaterials as well as novel therapeutic strategies have emerged to achieve the high-performance RIT of cancer. In this review article, we summarize recent advances in biomaterial-mediated RIT of cancer and provide guidance for non-experts to understand nuclear medicine and to conduct cancer radiotherapy.

Versatile labeling of multiple radionuclides onto a nanoscale metal-organic framework for tumor imaging and radioisotope therapy

Radionuclides for cancer theranostic have confronted problems such as limitation in real-time visualization and unsatisfactory therapeutic effect sacrificed by the nonspecific distribution. Nanoscale metal-organic frameworks (nMOFs) have been widely used in biomedical applications including cancer imaging and drug delivery. However, there have been rare reports utilizing nMOFs as a single nanoplatform to label various radionuclides for tumor imaging and radioisotope therapy (RIT). In this work, we developed polyethylene glycol (PEG) modified zirconium-based nMOFs (PCN-224) with favorable size, water solubility and biocompatibility. Interestingly, without the help of chelating agents, metal radionuclides (technetium-99 m/^99mTc, lutetium-177/¹⁷⁷Lu) could be efficiently labeled onto nMOFs via chelating with the porphyrin structure and iodine-125 (¹²⁵I) via chemical substitution of hydrogen in the benzene ring. The radionuclide-labeled PCN-PEG nanoparticles all exhibit excellent radiolabeling stability in different solutions. In accordance with the fluorescence imaging of mice injected with PCN-PEG, SPECT/CT imaging illustrates strong tumor accumulation of ^99mTc-PCN-PEG. Moreover, ¹⁷⁷Lu-PCN-PEG significantly inhibited the growth of tumor without inducing any perceptible toxicity to the treated mice. Hence, the radionuclide-delivery nanoplatform based on nMOFs would provide more opportunities for precise tumor theranostics and expand the biomedical applications of MOF nanomaterials.

Multi-functional Nanodrug Based on a Three-dimensional Framework for Targeted Photo-chemo Synergetic Cancer Therapy

Targeted synergistic therapy has broad prospects in tumor treatments. Here, a multi-functional nanodrug GDYO-CDDP/DOX@DSPE-PEG-MTX (GCDM) based on three traditional anticancer drugs (doxorubicin (DOX), cisplatin (CDDP) and methotrexate (MTX)) modified graphdiyne oxide (GDYO) is described, for diagnosis and targeted cancer photo-chemo synergetic therapy. In this system, for the first time, these three traditional anti-cancer drugs have played new roles and can reduce multidrug resistance through synergistic anti-tumor effects. Cisplatin can be hybridized with GDYO to form a multifunctional and well-dispersed three-dimensional framework, which can not only be used as nano-drug carriers to achieve high drug loading rates (40.3%), but also exhibit excellent photothermal conversion efficiency (47%) and good photodynamic effects under NIR irradiation. Doxorubicin (DOX) is loaded onto GDYO-CDDP through π-π stacking, which is used as an anticancer drug and as a fluorescent probe for nanodrug detection. Methotrexate (MTX) can be applied in tumor targeting and play a role in synergistic chemotherapy with DOX and CDDP. The synthesized multi-functional nanodrug GCDM has good biocompatibility, active targeting, long-term retention, sustained drug release, excellent fluorescence imaging capabilities, and remarkable photo-chemo synergistic therapeutic effects.

Polydopamine-Ag composite surface guides HBMSCs adhesion and proliferation

Human bone marrow mesenchymal stem cells (HBMSCs) are regarded as an important resource in the field of maxillofacial bone regeneration because of their favorable properties when compared with other stem cells. Hence, finding suitable materials that could extend the application of HBMSCs has become an emerging medical topic and socioeconomic problem. In this work, polydopamine (PDA)-Ag surface was fabricated by PDA assisted photoreduction method, and the obtained PDA-Ag composite surface significantly promoted HBMSCs adhesion and proliferation. This effect is highly related to the amount of Ag nanoparticles (Ag NPs) present on the PDA surface. The behavior of HBMSCs on PDA-Ag surface could be spatially manipulated by controlling the distribution of Ag NPs on PDA surface (by controlling UV light). The general adhesion property allows the PDA-Ag surface to be fabricated on various substrates, making it a simple, general and controllable method for the fabrication of bioactive surface for HBMSCs.

Construction of Surface-Modified Polydopamine Nanoparticles for Sequential Drug Release and Combined Chemo-Photothermal Cancer Therapy

Single chemotherapy often causes severe adverse effects and drug resistance to limit therapeutic efficacy. As a noninvasive approach, photothermal therapy (PTT) represents an attractive option for cancer therapy due to the benefits of remote control and precise treatment methods. Nanomedicines constructed with combined chemo-photothermal properties may exert synergistic effects and improved antitumor efficacy. In this study, we developed polydopamine (PDA)-coated nanoparticles grafted with folic acid (FA) and polyethylene glycol to transport doxorubicin (DOX) for targeted cancer therapy. The results showed that this delivery vehicle has a nanoscale particle size and narrow size distribution. No particle aggregation or significant drug leakage was observed during the stability test. This system presented excellent photothermal conversion capability under near-infrared light (NIR) laser irradiation due to the PDA layer covering. In vitro dissolution profiles demonstrated that sequential and triggered DOX release from nanoparticles was pH-, NIR irradiation-, and redox level-dependent and could be best fitted with the Ritger-Peppas equation. FA modification effectively promoted the intracellular uptake of nanoparticles by HepG2 cells and therefore significantly inhibited cell recovery and induced tumor cell apoptosis. Compared to the free DOX group, nanoparticles reduced the DOX concentration in the heart to avoid drug-related cardiotoxicity. More importantly, the in vivo antitumor efficacy results showed that compared with the single chemotherapy strategy, the nanoparticle group exerted combined and satisfactory tumor growth inhibition effects with good biocompatibility. In summary, this nanocarrier delivery system can organically combine chemotherapy and PTT to achieve effective and precise cancer treatment.

Melanin-Like Nanomedicine in Photothermal Therapy Applications

Photothermal therapy (PTT) mediated by nanomaterial has become an attractive tumor treatment method due to its obvious advantages. Among various nanomaterials, melanin-like nanoparticles with nature biocompatibility and photothermal conversion properties have attracted more and more attention. Melanin is a natural biological macromolecule widely distributed in the body and displays many fascinating physicochemical properties such as excellent biocompatibility and prominent photothermal conversion ability. Due to the similar properties, Melanin-like nanoparticles have been extensively studied and become promising candidates for clinical application. In this review, we give a comprehensive introduction to the recent advancements of melanin-like nanoparticles in the field of photothermal therapy in the past decade. In this review, the synthesis pathway, internal mechanism and basic physical and chemical properties of melanin-like nanomaterials are systematically classified and evaluated. It also summarizes the application of melanin-like nanoparticles in bioimaging and tumor photothermal therapy (PTT)in detail and discussed the challenges they faced in clinical translation rationally. Overall, melanin-like nanoparticles still have significant room for development in the field of biomedicine and are expected to applied in clinical PTT in the future.

Holo-lactoferrin: the link between ferroptosis and radiotherapy in triple-negative breast cancer

Rationale: Iron-saturated Lf (Holo-Lactoferrin, Holo-Lf) exhibits a superior anticancer property than low iron-saturated Lf (Apo-Lf). Ferroptosis is an iron-dependent cell death characterized by the accumulation of lipid peroxidation products and lethal reactive oxygen species (ROS). Radiotherapy also exerts its therapeutic effect through ROS.

Methods: The effect of different iron-saturated Lf on ferroptosis and radiotherapy were tested on triple-negative breast cancer (TNBC) cell line MDA-MB-231 and non-TNBC cell line MCF-7.

Results: Holo-Lf significantly increased the total iron content, promoted ROS generation, increased lipid peroxidation end product, malondialdehyde (MDA), and enhanced ferroptosis of MDA-MB-231 cells. By contrast, Apo-Lf upregulated SLC7a11 expression, increased GSH generation and inhibited ferroptosis of MDA-MB-231 cells. However, non-TNBC MCF-7 cells were resistant to Holo-Lf-induced ferroptosis because MCF-7 cells have a higher redox balance capacity than MDA-MB-231 cells. More importantly, Holo-Lf downregulated HIF-1α expression, ameliorated the hypoxia microenvironment in subcutaneous MDA-MB-231 tumors, and promoted radiation-induced DNA damage to hypoxic MDA-MB-231 cells. Finally, the efficacy of radiotherapy to MDA-MB-231 tumors was enhanced by Holo-Lf.

Conclusion: Holo-Lf could induce ferroptosis in MDA-MB-231 cells and sensitize MDA-MB-231 tumors to radiotherapy.

A Functionalized Polydopamine Theranostic Nanoprobe for Efficient Imaging of miRNA-21 and In Vivo Synergetic Cancer Therapy

MicroRNAs (miRNAs) are emerging as vital biomarkers since their abnormal expression is associated with various disease types including cancer. Therefore, it is essential to develop a sensitive and specific platform to monitor the dynamic expression of miRNAs for early clinical diagnosis and treatment. In this study, we designed a functionalized polydopamine (PDA)-based theranostic nanoprobe for efficient detection of miRNA-21 and in vivo synergistic cancer therapy. PDA was modified with polyethylene glycol (PEG) and the obtained PDA-PEG nanoparticles showed good stability in different solutions. PDA-PEG nanoparticles were loaded with fluorescein isothiocyanate (FITC)-labeled hairpin DNA (hpDNA) and an anticancer drug doxorubicin (DOX). In the absence of miRNA-21, PDA effectively quenched the fluorescence of FITC-labeled hpDNA. The presence of miRNA-21 specifically recognized hpDNA and induced the dissociation of hpDNA from PDA-PEG and subsequently recovered the fluorescence signals. Upon cellular uptake of these nanoprobes, a dose-dependent fluorescence activation and synergetic cytotoxic effect were observed due to the release of DOX and inhibition of miRNA-21 function. Furthermore, PDA-PEG-DOX-hpDNA nanoparticles can afford long-term monitoring of miRNA-21 and combined therapeutic efficacy in the nude mice bearing 4T1 tumors. Our results demonstrate the capability of PDA-PEG-DOX-hpDNA as a theranostic nanoprobe for continuously tracking of miRNAs and synergetic cancer therapy.

Metal-Containing Polydopamine Nanomaterials: Catalysis, Energy, and Theranostics

Polydopamine (PDA) is a major type of artificial melanin material with many interesting properties such as antioxidant activity, free-radical scavenging, high photothermal conversion efficiency, and strong metal-ion chelation. The high affinity of PDA to a wide range of metals/metal ions has offered a new class of functional metal-containing polydopamine (MPDA) nanomaterials with promising functions and extensive applications. Understanding and controlling the metal coordination environment is vital to achieve desirable functions for which such materials can be exploited. MPDA nanomaterials with metal/metal ions as the active functions are reviewed, including their synthesis and metal coordination environment and their applications in catalysis, batteries, solar cells, capacitors, medical imaging, cancer therapy, antifouling, and antibacterial coating. The current trends, limitations, and future directions of this area are also explored.

Combined Therapeutic Effects of 131I-Labeled and 5Fu-Loaded Multifunctional Nanoparticles in Colorectal Cancer

Background

Owing to its combined effects, the co-delivery of different therapeutics is a promising option for the treatment of cancer. In the present study, tumor-targeting poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) nanoparticles were developed for the transportation of two molecules, namely chemotherapeutic drug 5-fluorouracil (5Fu) and radionuclide iodine-131 (¹³¹I), in a single platform.

Methods

The obtained nanoparticles (Cetuximab [Cet]-PEG-PLA-5Fu-¹³¹I) were spherical (diameter approximately 110 nm) and pH-sensitive. The targeting effect of nanoparticles via Cet was confirmed in colorectal cancer cells using a fluorescent assay. The combined effects of Cet-PEG-PLA-5Fu-¹³¹I on cell viability and apoptosis were evaluated in colorectal cancer cells by Cell Counting Kit-8 and flow cytometry assays.

Results

Blank nanoparticles (Cet-PEG-PLA) showed good biocompatibility, and Cet-PEG-PLA-5Fu-¹³¹I nanoparticles were the most effective in terms of inhibition of cell viability and induction of apoptosis compared with monotherapy using Cet-PEG-PLA-5Fu or Cet-PEG-PLA-¹³¹I. In the xenograft mouse model, compared with using Cet-PEG-PLA-5Fu or Cet-PEG-PLA-¹³¹I alone, Cet-PEG-PLA-5Fu-¹³¹I nanoparticles exhibited prolonged circulation in the blood and accumulation in the tumor, thus resulting in enhanced antitumor efficacy. Additionally, combined radio-chemotherapy with Cet-PEG-PLA-5Fu-¹³¹I nanoparticles was associated with smaller tumor sizes than monotherapy, revealing the superior antitumor effects of Cet-PEG-PLA-5Fu-¹³¹I nanoparticles. These effects were further evidenced by histological and immunohistochemical analyses.

Conclusion

The multifunctional Cet-PEG-PLA-5Fu-¹³¹I nanoparticles are promising candidates for the co-delivery of 5Fu-mediated chemotherapy and ¹³¹I-mediated radiotherapy.

Melanin-Like Nanomaterials for Advanced Biomedical Applications: A Versatile Platform with Extraordinary Promise

Developing efficient, sustainable, and biocompatible high-tech nanoplatforms derived from naturally existing components in living organisms is highly beneficial for diverse advanced biomedical applications. Melanins are nontoxic natural biopolymers owning widespread distribution in various biosystems, possessing fascinating physicochemical properties and playing significant physiological roles. The multifunctionality together with intrinsic biocompatibility renders bioinspired melanin-like nanomaterials considerably promising as a versatile and powerful nanoplatform with broad bioapplication prospects. This panoramic Review starts with an overview of the fundamental physicochemical properties, preparation methods, and polymerization mechanisms of melanins. A systematical and well-bedded description of recent advancements of melanin-like nanomaterials regarding diverse biomedical applications is then given, mainly focusing on biological imaging, photothermal therapy, drug delivery for tumor treatment, and other emerging biomedicine-related implementations. Finally, current challenges toward clinical translation with an emphasis on innovative design strategies and future striving directions are rationally discussed. This comprehensive and detailed Review provides a deep understanding of the current research status of melanin-like nanomaterials and is expected to motivate further optimization of the design of novel tailorable and marketable multifunctional nanoplatforms in biomedicine.

Bone-Seeking Albumin-Nanomedicine for In Vivo Imaging and Therapeutic Monitoring

Malignant osteolysis associated with irreversible primary bone tumors and bone metastases remains a clinically urgent problem. Exploiting the imaging and therapy function of flexible nanomedicine can provide an alternative for therapeutic navigation and monitoring of malignant osteolysis. Here, we report the development of albumin-based gadolinium oxide nanoparticles loaded with doxorubicin and conjugated with bone-seeking alendronate for targeted delivery and therapeutic monitoring. Compared with nontargeted nanomedicine, bone-seeking accumulation and retention can be proven by MRI in a rat model of focal malignant osteolysis. Meanwhile, we observed a whole-body distribution in the consecutive SPECT imaging after radiolabeling with ¹²⁵I, SPECT imaging also indicated the enhanced bone tumor accumulation and prolonged retention. Resulting from the high drug loading and ¹³¹I labeling efficiency, the targeted nanomedicine exhibited significant chemotherapy and inter-radiotherapy capacity. Ultimately, the tumor burden of rats was obviously decreased except for the nontargeted group and the empty carrier group. In vivo CT imaging and pathological analysis revealed that the combined therapy was an efficient measure for antiosteolysis. Our findings suggest that albumin-based nanomedicine can provide a platform for bone-seeking diagnosis and therapeutic monitoring.

A Trojan horse biomimetic delivery strategy using mesenchymal stem cells for PDT/PTT therapy against lung melanoma metastasis

Mesenchymal stem cell (MSC)-based biomimetic delivery has been actively explored for drug accumulation and penetration into tumors by taking advantage of the tumor-tropic and penetration properties of MSCs. In this work, we further demonstrated the feasibility of MSC-mediated nano drug delivery, which was characterized by the "Trojan horse"-like transport via an endocytosis-exocytosis-endocytosis process between MSCs and cancer cells. Chlorin e6 (Ce6)-conjugated polydopamine nanoparticles (PDA-Ce6) were developed and loaded into the MSCs. Phototherapeutic agents are safe to the MSCs, and their very low dark toxicity causes no impairment of the inherent properties of MSCs, including tumor-homing ability. The MSCs loaded with PDA-Ce6 (MSC-PDA-Ce6) were able to target and penetrate into tumors and exocytose 60% of the payloads in 72 h. The released PDA-Ce6 NPs could penetrate deep and be re-endocytosed by the cancer cells. MSC-PDA-Ce6 tended to accumulate in the lungs and delivered PDA-Ce6 into the tumors after intravenous injection in the mouse model with lung melanoma metastasis. Phototoxicity can be selectively triggered in the tumors by sequentially treating with near-infrared irradiation to induce photodynamic therapy (PDT) and photothermal therapy (PTT). The MSC-based biomimetic delivery of PDA-Ce6 nanoparticles is a potential method for dual phototherapy against lung melanoma metastasis.

131 I-Labeled Multifunctional Polyphosphazene Nanospheres for SPECT Imaging-Guided Radiotherapy of Tumors

Design of theranostic nanoplatforms represents a major topic for current nanomedicine. Here, the preparation of multifunctional poly(cyclotriphosphazene-co-polyethylenimine) nanospheres (PNSs) labeled with radionuclide ¹³¹ I for single photon emission computed tomography (SPECT) imaging-guided radiotherapy of tumors is reported. In this work, PNSs are prepared using hexachlorocyclotriphosphazene as a crosslinker to crosslink branched polyethylenimine (PEI) via a nucleophilic substitution reaction, modified with 3-(4'-hydroxyphenyl) propionic acid-OSu (HPAO) for ¹³¹ I labeling, and reacted with 1,3-propane sulfonate (1,3-PS) to render the particles with antifouling property, followed by acetylation of the remaining surface amines and labeling with ¹³¹ I. The acquired PNS.NHAc-HPAO(¹³¹ I)-PS particles are well characterized. It is shown that the multifunctional PNSs with an average size of 184 ± 29.3 nm exhibit favorable antifouling properties, high ¹³¹ I labeling efficiency (76.05 ± 3.75%), and excellent radiostability and colloidal stability. With these properties owned, the developed PNS.NHAc-HPAO(¹³¹ I)-PS spheres enable much more efficient SPECT imaging and radiotherapy of a xenografted tumor model in vivo than the PEI counterpart material (PEI.NHAc-HPAO(¹³¹ I)-PS). The developed PNSs may be used as a versatile platform for further development of different forms of nanomedicine for various biomedical applications.

131I-labeled polyethylenimine-entrapped gold nanoparticles for targeted tumor SPECT/CT imaging and radionuclide therapy

Purpose: Polyethylenimine (PEI) has been widely used as a versatile template to develop multifunctional nanosystems for disease diagnosis and treatment. In this study, we manufactured iodine-131 (131I)-labeled PEI-entrapped gold nanoparticles (Au PENPs) as a novel nanoprobe for single-photon emission computed tomography/computed tomography (SPECT/CT) imaging and radionuclide therapy. Materials and methods: PEI was PEGylated and sequentially conjugated with Buthus martensii Karsch chlorotoxin (BmK CT, a tumor-specific ligand which can selectively bind to MMP2), 3-(4'-hydroxyphenyl)propionic acid-OSu (HPAO), and fluorescein isothiocyanate to form the multifunctional PEI template for entrapment of Au NPs. Then, the PEI surface was radiolabeled with 131I via HPAO to produce the novel nanoprobe (BmK CT-Au PENPs-131I). Results: The synthesized multifunctional Au PENPs before and after 131I radiolabeling were well-characterized as follows: structure, X-ray attenuation coefficient, colloid stability, cytocompatibility, and radiochemical stability in vitro. Furthermore, BmK CT-Au PENPs-131I were suitable for targeted SPECT/CT imaging and radionuclide therapy of tumor cells in vitro and in a xenograft tumor model in vivo. Conclusion: The developed multifunctional Au PENPs are a promising theranostic platform for targeted imaging and treatment of different MMP2-overexpressing tumors.