Dual-Targeting Biomimetic Semiconducting Polymer Nanocomposites for Amplified Theranostics of Bone Metastasis

A review of combined imaging and therapeutic applications based on MNMs

Magnetic nanomaterials (MNMs) are nanoscale materials with inherent magnetic properties that can respond to external magnetic fields, typically composed of magnetic metals or metal oxides. These materials exhibit broad application prospects in medical imaging, targeted drug delivery, and cancer therapy due to their exceptional magnetic properties, biocompatibility, and surface functionalization capabilities. As multifunctional imaging contrast agents, magnetic nanomaterials have been extensively employed in magnetic resonance imaging, computed tomography, and positron emission tomography to enhance multimodal imaging, thereby improving image resolution and diagnostic accuracy. Additionally, as targeted drug carriers, they can be guided by external magnetic fields to achieve precise drug delivery, enhancing therapeutic efficacy while minimizing systemic side effects. In therapeutic applications, magnetic nanomaterials have been utilized in magnetic hyperthermia therapy and photothermal therapy, where they generate localized heat via alternating magnetic fields or photothermal conversion effects, enabling tumor microenvironment modulation and precise tumor ablation. This review systematically summarizes recent advances in the use of MNMs for medical imaging and therapy, with a particular focus on key technical challenges and emerging opportunities to achieve synergistic imaging and therapeutic functions. This work aims to provide valuable insight into the development of MNMs for applications in precision medicine and personalized therapy.

Nano-Drug Delivery Systems for Bone Metastases: Targeting the Tumor-Bone Microenvironment

Bone metastases are a prevalent and debilitating consequence of various cancers, including breast and prostate carcinomas, which significantly compromise patient quality of life due to pain, fractures, and other skeletal-related events (SREs). This review examines the pathophysiology of bone metastases, emphasizing the role of the bone microenvironment in tumor progression through mechanisms such as osteotropism and the dysregulated bone remodeling cycle. The primary focus is on the emerging nano-drug delivery systems (DDS) designed to target the bone microenvironment and improve the therapeutic index of anticancer agents. Current treatments, mainly comprising bisphosphonates and radiotherapy, provide palliative benefits but often have limited efficacy and significant side effects. Innovative strategies, such as bisphosphonate-conjugated nanoparticles and targeted therapies that utilize the unique bone marrow niche, are explored for their potential to enhance drug accumulation at metastatic sites while minimizing systemic toxicity. These approaches include the use of liposomes, polymeric nanoparticles, and inorganic nanoparticles, which can be functionalized to exploit the biological barriers within the bone microenvironment. This review also discusses the challenges and future directions for nano-DDS in clinical settings, emphasizing the need for multidisciplinary research to effectively integrate these technologies into standard care protocols.

Nanosensitizer-assisted sonodynamic therapy for breast cancer

Breast cancer is the most commonly diagnosed cancer worldwide. Despite advancements in therapeutic modalities, its prognosis remains poor owing to complex clinical, pathological, and molecular characteristics. Sonodynamic therapy (SDT) is a promising approach for tumor elimination, using sonosensitizers that preferentially accumulate in tumor tissues and are activated by low-intensity ultrasound to produce reactive oxygen species. However, the clinical translation of SDT faces challenges, including the limited efficiency of sonosensitizers and resistance posed by the tumor microenvironment. The emergence of nanomedicine offers innovative strategies to address these obstacles. This review discusses strategies for enhancing the efficacy of SDT using sonosensitizers, including rational structural modifications, improved tumor-targeted enrichment, tumor microenvironment remodeling, and imaging-guided therapy. Additionally, SDT-based multimodal therapies, such as sono-chemotherapy, sono-immunotherapy, and sono-photodynamic therapy, and their potential applications in breast cancer treatment are summarized. The underlying mechanisms of SDT in breast cancer are briefly outlined. Finally, this review highlights current challenges and prospects for the clinical translation of SDT, providing insights into future advancements that may improve therapeutic outcomes for breast cancer.

Recent research progress on metal ions and metal-based nanomaterials in tumor therapy

Tumors, as a disease that seriously threatens human health, have always been a major challenge in the field of medicine. Currently, the main methods of tumor treatment include surgery, radiotherapy, chemotherapy, etc., but these traditional treatment methods often have certain limitations. In addition, tumor recurrence and metastasis are also difficult problems faced in clinical treatment. In this context, the importance of metal-based nanomaterials in tumor therapy is increasingly highlighted. Metal-based nanomaterials possess unique physical, chemical, and biological properties, providing new ideas and methods for tumor treatment. Metal-based nanomaterials can achieve targeted therapy for tumors through various mechanisms, reducing damage to normal tissues; they can also serve as drug carriers, improving the stability and bioavailability of drugs; at the same time, some metal-based nanomaterials also have photothermal, photodynamic, and other characteristics, which can be used for phototherapy of tumors. This review examines the latest advances in the application of metal-based nanomaterials in tumor therapy within past 5 years, and presents prospective insights into the future applications.

Less is More: Biomimetic Hybrid Membrane Nanocarriers for Highly Efficient Tumor Targeted Drug Delivery

Biomimetic camouflaged nanocarriers coated with cancer cell membranes (CCMs) have attracted considerable research attention for drug delivery application. CCM-camouflaged nanocarriers have inherent tumor-homologous targeting ability. However, they enter cancer cells via endocytosis, which is not efficient for drug delivery. Switching the internalization mechanism to membrane fusion may enhance their delivery efficiency. In this study, an innovative biomimetic-targeting nanocarrier is designed by hybridizing CCMs with pH-sensitive liposomes (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine liposomes, DOPE-Lipo), named as CCMpHD. The presence of CCMs makes the nanocarriers capable of homologous targeting, and the DOPE-Lipo hybrid allows the nanocarriers to achieve efficient internalization via membrane fusion. Notably, the cellular uptake of CCMpHD is significantly higher than that of the CCMs. The most efficient delivery is achieved with 1/10 CCMs, which requires remarkably less cell membranes. Doxorubicin (DOX) is used as a model drug to characterize the homologous targeting drug delivery properties of the hybrid nanocarriers. Both in vitro and in vivo experiments demonstrated that the nanocarriers exhibited satisfactory biosafety and enhanced tumor-targeted delivery. With enhanced delivery efficiency whilst requiring fewer CCMs, these hybrid membrane nanocarriers provides a new strategy for CCM-based drug delivery in cancer treatment.

Ca2+- and cGAMP-Contained Semiconducting Polymer Nanomessengers for Radiodynamic-Activated Calcium Overload and Immunotherapy

Various second messengers exert some vital actions in biological systems, including cancer therapy, but the therapeutic efficacy is often need to be improved. A semiconducting polymer nanomessenger (TCa/SPN/a) consisting of two second messengers, calcium ion (Ca2+) and cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) for metastatic breast cancer therapy, is reported here. Such a TCa/SPN/a is constructed to exhibit X-ray response for the activatable delivery of mitochondria-targeting Ca compound and cGAMP as stimulator of interferon genes (STING) agonist. With X-ray irradiation, TCa/SPN/a could generate singlet oxygen (1O2) via radiodynamic effect for ablating solid tumors and improving the tumor immunogenicity by inducing immunogenic cell death (ICD). Furthermore, the released mitochondria-targeting Ca compounds show a high binging effect on mitochondria and cause reactive oxygen species (ROS) generation and mitochondria damage via calcium overload, while cGAMP boosts immunological effect through activating STING pathway. In this way, TCa/SPN/a enables a radiodynamic-activated calcium overload and immunotherapy to obviously inhibit the growths of bilateral tumors and also abolish tumor metastasis in metastatic breast cancer mouse models. This article should demonstrate the first smart dual-functional nanotherapeutic containing two second messengers for precise and specific cancer therapy.

Cleavage of Homonuclear Chalcogen-Chalcogen Bonds in a Hybrid Platform in Response to X-Ray Radiation Potentiates Tumor Radiochemotherapy

Chalcogens are used as sensitive redox-responsive reagents in tumor therapy. However, chalcogen bonds triggered by external ionizing radiation, rather than by internal environmental stimuli, enable site-directed and real-time drug degradation in target lesions. This approach helps to bypass chemoresistance and global systemic toxicity, presenting a significant advancement over traditional chemoradiotherapy. In this study, we fabricated a hybrid monodisperse organosilica nanoprodrug based on homonuclear single bonds (disulfide bonds (S-S, approximately 240 kJ/mol), diselenium bonds (Se-Se, approximately 172 kJ/mol), and tellurium bonds (Te-Te, 126 kJ/mol)), including ditelluride-bond-bridged MONs (DTeMSNs), diselenide-bond-bridged MONs (DSeMSNs) and disulfide-bond-bridged MONs (DSMSNs). The results demonstrated that differences in electronegativities and atomic radii influenced their oxidation sensitivities and reactivities. Tellurium, with the lowest electronegativity, showed the highest sensitivity, followed by selenium and sulfur. DTeMSNs exhibited highly responsive cleavage upon exposure to X-rays, resulting in oxidation to TeO3 2-. Furthermore, chalcogen-hybridized organosilica was loaded with manganese ions (Mn2+) to enhance the release of Mn2+ during radiotherapy, thereby activating the the stimulator of interferon genes (STING) pathway and enhancing the tumor immune response to inhibit tumor growth. This investigation of hybrid organosilica deepens our understanding of chalcogens response characteristics to radiotherapy and enriches the design principles for nanomedicine based on prodrugs.

Nanotheranostics in Breast Cancer Bone Metastasis: Advanced Research Progress and Future Perspectives

Breast cancer is the leading cause of cancer-related morbidity and mortality among women worldwide, with bone being the most common site of all metastatic breast cancer. Bone metastases are often associated with pain and skeletal-related events (SREs), indicating poor prognosis and poor quality of life. Most current therapies for breast cancer bone metastasis primarily serve palliative purposes, focusing on pain management, mitigating the risk of bone-related complications, and inhibiting tumor progression. The emergence of nanodelivery systems offers novel insights and potential solutions for the diagnosis and treatment of breast cancer-related bone metastasis. This article reviews the recent advancements and innovative applications of nanodrug delivery systems in the context of breast cancer bone metastasis and explores future directions in nanotheranostics.

Nanosonosensitizer Optimization for Enhanced Sonodynamic Disease Treatment

Low-intensity ultrasound-mediated sonodynamic therapy (SDT), which, by design, integrates sonosensitizers and molecular oxygen to generate therapeutic substances (e.g., toxic hydroxyl radicals, superoxide anions, or singlet oxygen) at disease sites, has shown enormous potential for the effective treatment of a variety of diseases. Nanoscale sonosensitizers play a crucial role in the SDT process because their structural, compositional, physicochemical, and biological characteristics are key determinants of therapeutic efficacy. In particular, advances in materials science and nanotechnology have invigorated a series of optimization strategies for augmenting the therapeutic efficacy of nanosonosensitizers. This comprehensive review systematically summarizes, discusses, and highlights state-of-the-art studies on the current achievements of nanosonosensitizer optimization in enhanced sonodynamic disease treatment, with an emphasis on the general design principles of nanosonosensitizers and their optimization strategies, mainly including organic and inorganic nanosonosensitizers. Additionally, recent advancements in optimized nanosonosensitizers for therapeutic applications aimed at treating various diseases, such as cancer, bacterial infections, atherosclerosis, and autoimmune diseases, are clarified in detail. Furthermore, the biological effects of the improved nanosonosensitizers for versatile SDT applications are thoroughly discussed. The review concludes by highlighting the current challenges and future opportunities in this rapidly evolving research field to expedite its practical clinical translation and application.

Surface Engineering of Magnetic Iron Oxide Nanoparticles for Breast Cancer Diagnostics and Drug Delivery

Data published in 2020 by the International Agency for Research on Cancer (IARC) of the World Health Organization show that breast cancer (BC) has become the most common cancer globally, affecting more than 2 million women each year. The complex tumor microenvironment, drug resistance, metastasis, and poor prognosis constitute the primary challenges in the current diagnosis and treatment of BC. Magnetic iron oxide nanoparticles (MIONPs) have emerged as a promising nanoplatform for diagnostic tumor imaging as well as therapeutic drug-targeted delivery due to their unique physicochemical properties. The extensive surface engineering has given rise to multifunctionalized MIONPs. In this review, the latest advancements in surface modification strategies of MIONPs over the past five years are summarized and categorized as constrast agents and drug delivery platforms. Additionally, the remaining challenges and future prospects of MIONPs-based targeted delivery are discussed.

NK-92 cells labeled with Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobes for the targeted treatment and noninvasive therapeutic evaluation of breast cancer

Adoptive cellular immunotherapy as a promising and alternative cancer therapy platform is critical for future clinical applications. Natural killer (NK) cells have attracted attention as an important type of innate immune regulatory cells that can rapidly kill multiple adjacent cancer cells. However, these cells are significantly less effective in treating solid tumors than in treating hematological tumors. Herein, we report the synthesis of a Fe3O4-PEG-CD56/Avastin@Ce6 nanoprobe labeled with NK-92 cells that can be used for adoptive cellular immunotherapy, photodynamic therapy and dual-modality imaging-based in vivo fate tracking. The labeled NK-92 cells specifically target the tumor cells, which increases the amount of cancer cell apoptosis in vitro. Furthermore, the in vivo results indicate that the labeled NK-92 cells can be used for tumor magnetic resonance imaging and fluorescence imaging, adoptive cellular immunotherapy, and photodynamic therapy after tail vein injection. These data show that the developed multifunctional nanostructure is a promising platform for efficient innate immunotherapy, photodynamic treatment and noninvasive therapeutic evaluation of breast cancer.