Advanced Nanotechnology Leading the Way to Multimodal Imaging-Guided Precision Surgical Therapy

MoS2 nanoflowers surface decorated with CuS nanorods and carbon dots for fluorescent and ultrasound imaging in cancer therapy

In recent years, the design of various ultrasound responsive echogenic nanomaterials offers many advantages such as deep tissue penetration, high signal intensity, colloidal stability, biocompatibility and less expensive for ultrasound-based cancer cell imaging while providing the option to monitor the progress of tumor volume during the treatment. Further, the ability of nanomaterials to combine photo-thermal therapy (PTT) and chemotherapy has opened a new avenue in the development of cancer theranostics for synergistic cancer therapy. Herein, we report MoS2 nanoflowers (NFs) surface decorated with CuS nanorods (NRs) and folic acid-derived carbon dots (FACDs) using cystine-polyethyleneimine (PEI) linker for PTT-chemotherapy. The size of NFs was found to be 350 ± 50 nm which increased to 500 ± 50 nm after surface decoration. The morphology of MoS2 NFs before and after surface decoration was investigated using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and UV-Vis-NIR spectroscopy. The photo-thermal heat generation was found to be increasing as a function of the concentration of NFs. The encapsulation efficiency of doxorubicin (DOX) and photo-thermal conversion efficiency (PCE) for surface-decorated MoS2 NFs (MoS2@CuS/FACDs NFs) was estimated to be 42 and 44 %, respectively. The surface decoration of CuS NRs and FACDs on MoS2 NFs not only improved the anticancer activity but also increased the signal intensity in ultrasound and fluorescence imaging of cancer cells. The MoS2@CuS/FACDs NFs exhibited excellent cytotoxicity against MDA-MB-231 cancer cells. Hence, the hybrid system demonstrated here showed high potential for use as a combined probe for non-invasive ultrasound imaging and fluorescence imaging for PTT-chemotherapy.

Diagnostics of brain tumor in the early stage: current status and future perspectives

Early diagnosis of brain tumors is challenging due to their complexity and delicate structure. Conventional imaging techniques like MRI, CT, and PET are unable to provide detailed visualization of early-stage brain tumors. Early-stage detection of brain tumors is vital for enhancing patient outcomes and survival rates. So far, several scientists have dedicated their efforts to innovating advanced diagnostic probes to efficiently cross the BBB and selectively target brain tumors for optimal imaging. The integration of these techniques presents a viable pathway for non-invasive, accurate, and early-stage tumor identification. Herein, we provide a timely update on the various imaging probes and potential challenges for the diagnosis of early-stage brain tumors. Furthermore, this review highlights the significance of integrating advanced imaging probes for improving the early detection of brain tumors, ultimately enhancing treatment outcomes. Hopefully, this review will stimulate the interest of researchers to accelerate the development of new imaging probes and even their clinical translation for improving the early diagnosis of brain tumors.

Fluorescence-guided Surgery for Hepatocellular Carcinoma: From Clinical Practice to Laboratories

Fluorescence navigation is a novel technique for accurately identifying hepatocellular carcinoma (HCC) lesions during hepatectomy, enabling real-time visualization. Indocyanine green-based fluorescence guidance has been commonly used to demarcate HCC lesion boundaries, but it cannot distinguish between benign and malignant liver tumors. This review focused on the clinical applications and limitations of indocyanine green, as well as recent advances in novel fluorescent probes for fluorescence-guided surgery of HCC. It covers traditional fluorescent imaging probes such as enzymes, reactive oxygen species, reactive sulfur species, and pH-sensitive probes, followed by an introduction to aggregation-induced emission probes. Aggregation-induced emission probes exhibit strong fluorescence, low background signals, excellent biocompatibility, and high photostability in the aggregate state, but show no fluorescence in dilute solutions. Design strategies for these probes may offer insights for developing novel fluorescent probes for the real-time identification and navigation of HCC during surgery.

Nanomaterial-Based Molecular Imaging in Cancer: Advances in Simulation and AI Integration

Nanomaterials represent an innovation in cancer imaging by offering enhanced contrast, improved targeting capabilities, and multifunctional imaging modalities. Recent advancements in material engineering have enabled the development of nanoparticles tailored for various imaging techniques, including magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and ultrasound (US). These nanoscale agents improve sensitivity and specificity, enabling early cancer detection and precise tumor characterization. Monte Carlo (MC) simulations play a pivotal role in optimizing nanomaterial-based imaging by modeling their interactions with biological tissues, predicting contrast enhancement, and refining dosimetry for radiation-based imaging techniques. These computational methods provide valuable insights into nanoparticle behavior, aiding in the design of more effective imaging agents. Moreover, artificial intelligence (AI) and machine learning (ML) approaches are transforming cancer imaging by enhancing image reconstruction, automating segmentation, and improving diagnostic accuracy. AI-driven models can also optimize MC-based simulations by accelerating data analysis and refining nanoparticle design through predictive modeling. This review explores the latest advancements in nanomaterial-based cancer imaging, highlighting the synergy between nanotechnology, MC simulations, and AI-driven innovations. By integrating these interdisciplinary approaches, future cancer imaging technologies can achieve unprecedented precision, paving the way for more effective diagnostics and personalized treatment strategies.

Aggregation induced emission luminogen bacteria hybrid bionic robot for multimodal phototheranostics and immunotherapy

Multimodal phototheranostics utilizing single molecules offer a "one-and-done" approach, presenting a convenient and effective strategy for cancer therapy. However, therapies based on conventional photosensitizers often suffer from limitations such as a single photosensitizing mechanism, restricted tumor penetration and retention, and the requirement for multiple irradiations, which significantly constrain their application. In this report, we present an aggregation-induced emission luminogen (AIEgen) bacteria hybrid bionic robot to address above issues. This bionic robot is composed of multifunctional AIEgen (INX-2) and Escherichia coli Nissle 1917 (EcN), i.e., EcN@INX-2. The EcN@INX-2 bionic robot exhibits near-infrared II (NIR-II) fluorescence emission and demonstrates efficient photodynamic and photothermal effects, as well as tumor-targeting capabilities. These features are facilitated by the complementary roles of INX-2 and EcN. The robot successfully enables in vivo multimodal imaging and therapy of colon cancer models in female mice through various mechanisms, including the activation of anti-tumor immunity, as well as photodynamic and photothermal therapy. Our study paves an avenue for designing multifunctional diagnostic agents for targeted colon cancer therapy through image-guided combinational immunotherapy.

Design, synthesis, biological evaluation and molecular docking of novel isatin-oxime ether derivatives as potential IDH1 inhibitors

A series of novel isatin-oxime ether derivatives were designed, synthesized and characterized by 1H NMR and 13C NMR and HRMS. These compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines (A549, HepG2 and Hela) by MTT assay. According to the experimental results, compounds 6a (IC50 = 0.34μM), 6c (IC50 = 14nM) and 6r (IC50 = 45nM) were found as the excellent selectivity and high activity against A549, whereas compounds 6m (IC50 = 12nM) and 6n (IC50 = 25nM) displayed the significant activity for HepG2, respectively. Compound 6f (IC50 = 30nM), 6n (IC50 = 9nM) and 6o (IC50 = 20nM) also showed the excellent activity against Hela. From the experiments of cell migration and colony formation assays, the findings demonstrated that 6m can effectively suppress the migration and growth of HepG2 cells. In addition, the results of molecular docking studies determined the strong binding interactions between the potential active compounds 6m and 6n and the active sites of isocitrate dehydrogenase 1 (IDH1) with the lowest binding affinity energy.

Nanomaterial-assisted delivery of CpG oligodeoxynucleotides for boosting cancer immunotherapy

Cancer immunotherapy aims to improve immunity to not only eliminate the primary tumor but also inhibit metastasis and recurrence. It is considered an extremely promising therapeutic approach that breaks free from the traditional paradigm of oncological treatment. As the medical community learns more about the immune system's mechanisms that "turn off the brake" and "step on the throttle", there is increasingly successful research on immunomodulators. However, there are still more restrictions than countermeasures with immunotherapy related to immunomodulators, such as low responsiveness and immune-related adverse events that cause multiple adverse reactions. Therefore, medical experts and materials scientists attempted to the efficacy of immunomodulatory treatments through various methods, especially nanomaterial-assisted strategies. CpG oligodeoxynucleotides (CpG) not only act as an adjuvant to promote immune responses, but also induce autophagy. In this review, the enhancement of immunotherapy using nanomaterial-based CpG formulations is systematically elaborated, with a focus on the delivery, protection, synergistic promotion of CpG efficacy by nanomaterials, and selection of the timing of treatment. In addition, we also discuss and prospect the existing problems and future directions of research on nanomaterials in auxiliary CpG therapy.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

A Renal Clearable Nano-Assembly with Förster Resonance Energy Transfer Amplified Superoxide Radical and Heat Generation to Overcome Hypoxia Resistance in Phototherapeutics

Given that type I photosensitizers (PSs) possess a good hypoxic tolerance, developing an innovative tactic to construct type I PSs is crucially important, but remains a challenge. Herein, we present a smart molecular design strategy based on the Förster resonance energy transfer (FRET) mechanism to develop a type I photodynamic therapy (PDT) agent with an encouraging amplification effect for accurate hypoxic tumor therapy. Of note, benefiting from the FRET effect, the obtained nanostructured type I PDT agent (NanoPcSZ) with boosted light-harvesting ability not only amplifies superoxide radical (O2 •-) production but also promotes heat generation upon near-infrared light irradiation. These features facilitate NanoPcSZ to realize excellent phototherapeutic response under both normal and hypoxic environments. As a result, both in vitro and in vivo experiments achieved a remarkable improvement in therapeutic efficacy via the combined effect of photothermal action and type I photoreaction. Notably, NanoPcSZ can be eliminated from organs (including the liver, lung, spleen, and kidney) apart from the tumor site and excreted through urine within 24 h of its systemic administration. In this way, the potential biotoxicity of drug accumulation can be avoided and the biosafety can be further enhanced.

Programmable bionanomaterials for revolutionizing cancer immunotherapy

Cancer immunotherapy involves a cutting-edge method that utilizes the immune system to detect and eliminate cancer cells. It has shown substantial effectiveness in treating different types of cancer. As a result, its growing importance is due to its distinct benefits and potential for sustained recovery. However, the general deployment of this treatment is hindered by ongoing issues in maintaining minimal toxicity, high specificity, and prolonged effectiveness. Nanotechnology offers promising solutions to these challenges due to its notable attributes, including expansive precise surface areas, accurate ability to deliver drugs and controlled surface chemistry. This review explores the current advancements in the application of nanomaterials in cancer immunotherapy, focusing on three primary areas: monoclonal antibodies, therapeutic cancer vaccines, and adoptive cell treatment. In adoptive cell therapy, nanomaterials enhance the expansion and targeting capabilities of immune cells, such as T cells, thereby improving their ability to locate and destroy cancer cells. For therapeutic cancer vaccines, nanoparticles serve as delivery vehicles that protect antigens from degradation and enhance their uptake by antigen-presenting cells, boosting the immune response against cancer. Monoclonal antibodies benefit from nanotechnology through improved delivery mechanisms and reduced off-target effects, which increase their specificity and effectiveness. By highlighting the intersection of nanotechnology and immunotherapy, we aim to underscore the transformative potential of nanomaterials in enhancing the effectiveness and safety of cancer immunotherapies. Nanoparticles' ability to deliver drugs and biomolecules precisely to tumor sites reduces systemic toxicity and enhances therapeutic outcomes.

Advances in multifunctional metal-organic framework (MOF)-based nanoplatforms for cancer starvation therapy

Cancer remains a significant threat to human health today. Even though starvation therapy and other treatment methods have recently advanced to a new level of rapid development in tumour treatment, their limited therapeutic effectiveness and unexpected side effects prevent them from becoming the first option in clinical treatment. With rapid advancement in nanotechnology, the utilization of nanomaterials in therapeutics offers the potential to address the shortcomings in cancer treatment. Notably, multifunctional metal-organic framework (MOF) has been widely employed in cancer therapy due to their customizable shape, adjustable diameter, high porosity, diverse compositions, large specific surface area, high degree of functionalization and strong biocompatibility. This paper reviews the current progress and success of MOF-based multifunctional nanoplatforms for cancer starvation therapy, as well as the prospects and potential barriers for the application of MOF nanoplatforms in cancer starvation therapy.

Tadpole-Like Carbon Nanotube with Fe Nanoparticle Encapsulated at the Head and Zn Single-Atom Anchored on the Body: One-Pot Carbonization for Tetramodal Synergistic Cancer Therapy

Precise integration of diverse therapeutic approaches into nanomaterials is the key to the development of multimodal synergistic cancer therapy. In this work, tadpole-like carbon nanotubes with Fe nanoparticle encapsulated at the head and Zn single-atom anchored on the body (Fe@CNT-Zn) is precisely designed and facilely prepared via one-pot carbonization. In vitro studies revealed the integration of chemotherapy (CT), chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT) in Fe@CNT-Zn as well as the near-infrared light (NIR)-responsive cascade therapeutic efficacy. Furthermore, in vivo studies demonstrated the NIR-triggered cascade-amplifying synergistic cancer therapy in a B16 tumor-bearing mouse model. The results not only showcased the Fe@CNT-Zn as a potential tetramodal therapeutic platform, but also demonstrated a proof-of-concept on metal-organic framework-based "one stone for multiple birds" strategy for in situ functionalization of carbon materials.

NIR laser-activated phthalocyanine loaded lipid nanoparticles targeting M2 macrophage for improved photoacoustic imaging-guided photothermal therapy

The development of novel phototheranostic agents with significant potential in bioimaging-guided therapy is highly desirable for precise tumor therapy. Herein, NIR laser-activated ruthenium phthalocyanine (PcRu) loaded sub-30 nm targeting lipid nanoparticles (α-PcRu-NPs) were fabricated for photoacoustic imaging (PAI)-guided photothermal therapy (PTT). Due to the formation of J-type aggregation of PcRu in the core of the nanostructure, the α-PcRu-NPs exhibited high stability, efficient NIR absorption, reduced singlet oxygen generation, high photothermal activity, and intense photoacoustic signal. With the M2 macrophage target peptide (M2pep) modification and small size of α-PcRu-NPs, in vivo evaluations reveal that α-PcRu-NPs can specifically target and deeply penetrate the tumor foci. Under a high contrast PAI guidance with α-PcRu-NPs (744 nm, 0.35 μW), it also realizes superior photothermal therapy (PTT) for breast cancer under 670 nm laser irradiation (0.5 W/cm2). The prominent therapeutic efficacy of α-PcRu-NP-based PTT not only directly kills tumor cells, but also enhances the immune response by promoting dendritic cell maturation and increasing cytotoxic T cell infiltration. Thus, this work broadens the applications of phthalocyanine derivatives as phototheranostics in the PAI-guided PTT field.

Mechanism exploration of synergistic photo-immunotherapy strategy based on a novel exosome-like nanosystem for remodeling the immune microenvironment of HCC

The immunosuppressive tumor microenvironment (TME) has become a major challenge in cancer immunotherapy, with abundant tumor-associated macrophages (TAMs) playing a key role in promoting tumor immune escape by displaying an immunosuppressive (M2) phenotype. Recently, it was reported that M1 macrophage-derived nanovesicles (M1NVs) can reprogram TAMs to an anti-tumor M1 phenotype, thereby significantly alleviating the immunosuppressive TME and enhancing the anti-tumor efficacy of immunotherapy. Herein, we developed M1NVs loaded with mesoporous dopamine (MPDA) and indocyanine green (ICG), which facilitated the recruitment of M2 TAMs through synergistic photothermal and photodynamic therapy. Thereafter, M1NVs can induce M1 repolarization of TAMs, resulting in increased infiltration of cytotoxic T lymphocytes within the tumor to promote tumor regression. This study investigated the effect of phototherapy on the immune environment of liver cancer using single-cell RNA sequencing (scRNA-seq) by comparing HCC tissues before and after MPDA/ICG@M1NVs + NIR treatment. The results showed significant shifts in cell composition and gene expression, with decreases in epithelial cells, B cells, and macrophages and increases in neutrophils and myeloid cells. Additionally, gene analysis indicated a reduction in pro-inflammatory signals and immunosuppressive functions, along with enhanced B-cell function and anti-tumor immunity, downregulation of the Gtsf1 gene in the epithelial cells of the MPDA/ICG @M1NVs + NIR group, and decreased expression of the lars2 gene in immune subpopulations. Eno3 expression is reduced in M1 macrophages, whereas Clec4a3 expression is downregulated in M2 macrophages. Notably, the B cell population decreased, whereas Pou2f2 expression increased. These genes regulate cell growth, death, metabolism, and tumor environment, indicating their key role in HCC progression. This study highlights the potential for understanding cellular and molecular dynamics to improve immunotherapy.

A Tumor-Activatable Liposomal Nanoprobe for Selective Visualization of Metastatic Lymph Nodes

The precise identification of sentinel lymph nodes (SLNs) during surgery and assessment of their benign status is crucial for accurate tumor staging and optimal treatment strategizing. Currently, a deficiency exists in non-invasive in vivo diagnostic techniques that can accurately pinpoint SLNs during surgery while simultaneously evaluating their benign status. Here, a tumor-activatable liposomal nanoprobe (nTAL) is developed, remotely loaded with clinically approved photosensitizer, methyl aminolevulinate (MAL), to noninvasively visualize the tumor metastasis lymph nodes (LNs) with precision. Benefited from the highly efficient LNs draining of nanosized liposome and tumor cell-specific transformation of the non-fluorescent MAL to fluorescent protoporphyrin IX (PPIX), nTAL succeeded in targeting the SLNs and differentiated the metastatic from the benign ones with a positive correlation between PPIX generation and tumor cell infiltration in LNs. Moreover, the nTAL technology is capable of probing the early metastatic stage with a primary tumor size of 50 mm3. This study provides a new strategy for intraoperative visualization of real-time sentinel node dissection.

Advances in nanobubbles for cancer theranostics: Delivery, imaging and therapy

Maximizing treatment efficacy and forecasting patient prognosis in cancer necessitates the strategic use of targeted therapy, coupled with the prompt precise detection of malignant tumors. Theutilizationof gaseous systems as an adaptable platform for creating nanobubbles (NBs) has garnered significant attention as theranostics, which involve combining contrast chemicals typically used for imaging with pharmaceuticals to diagnose and treattumorssynergistically in apersonalizedmanner for each patient. This review specifically examines the utilization of oxygen NBsplatforms as a theranostic weapon in the field of oncology. We thoroughly examine the key factors that impact the effectiveness of NBs preparations and the consequences of these treatment methods. This review extensively examines recent advancements in composition schemes, advanced developments in pre-clinical phases, and other groundbreaking inventions in the area of NBs. Moreover, this review offers a thorough examination of the optimistic future possibilities, addressing prospective methods for improvement and incorporation into widely accepted therapeutic practices. As we explore the ever-changing field of cancer theranostics, the incorporation of oxygen NBs appears as a promising development, providing new opportunities for precision medicine and marking a revolutionary age in cancer research and therapy.

Recent progress in quantitative analysis of self-assembled peptides

Self-assembled peptides have been among the important biomaterials due to its excellent biocompatibility and diverse functions. Over the past decades, substantial progress and breakthroughs have been made in designing self-assembled peptides with multifaceted biomedical applications. The techniques for quantitative analysis, including imaging-based quantitative techniques, chromatographic technique and computational approach (molecular dynamics simulation), are becoming powerful tools for exploring the structure, properties, biomedical applications, and even supramolecular assembly processes of self-assembled peptides. However, a comprehensive review concerning these quantitative techniques remains scarce. In this review, recent progress in techniques for quantitative investigation of biostability, cellular uptake, biodistribution, self-assembly behaviors of self-assembled peptide etc., are summarized. Specific applications and roles of these techniques are highlighted in detail. Finally, challenges and outlook in this field are concluded. It is believed that this review will provide technical guidance for researchers in the field of peptide-based materials and pharmaceuticals, and facilitate related research for newcomers in this field.

X-ray activated near-infrared persistent luminescence nanoparticles for trimodality in vivo imaging

As promising luminescence nanoparticles, near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) have received extensive attention in the field of high-sensitivity bioimaging in recent years. However, NIR PLNPs face problems such as short excitation wavelengths and single imaging modes, which limit their applications in in vivo reactivated imaging and multimodal imaging. Here, we report for the first time novel Gd2GaTaO7:Cr3+,Yb3+ (GGTO) NIR PLNPs that integrate X-ray activated NIR persistent luminescence (PersL), high X-ray attenuation and excellent magnetic properties into a single nanoparticle (NP). In this case, Cr3+ is used as the luminescence center. The co-doped Yb3+ and coating effectively enhance the X-ray activated NIR PersL. At the same time, the presence of the high-Z element Ta also makes the GGTO NPs exhibit high X-ray attenuation performance, which can be used as a CT contrast agent to achieve in vivo CT imaging. In addition, since the matrix contains a large amount of Gd, the GGTO NPs show remarkable magnetic properties, which can realize in vivo MR imaging. GGTO NPs combine the trimodal benefits of X-ray reactivated PersL, CT and MR imaging and are suitable for single or combined applications that require high sensitivity and spatial resolution imaging.

Lipid-based nanosystems: the next generation of cancer immune therapy

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

Nanomaterial-Based Repurposing of Macrophage Metabolism and Its Applications

Macrophage immunotherapy represents an emerging therapeutic approach aimed at modulating the immune response to alleviate disease symptoms. Nanomaterials (NMs) have been engineered to monitor macrophage metabolism, enabling the evaluation of disease progression and the replication of intricate physiological signal patterns. They achieve this either directly or by delivering regulatory signals, thereby mapping phenotype to effector functions through metabolic repurposing to customize macrophage fate for therapy. However, a comprehensive summary regarding NM-mediated macrophage visualization and coordinated metabolic rewiring to maintain phenotypic equilibrium is currently lacking. This review aims to address this gap by outlining recent advancements in NM-based metabolic immunotherapy. We initially explore the relationship between metabolism, polarization, and disease, before delving into recent NM innovations that visualize macrophage activity to elucidate disease onset and fine-tune its fate through metabolic remodeling for macrophage-centered immunotherapy. Finally, we discuss the prospects and challenges of NM-mediated metabolic immunotherapy, aiming to accelerate clinical translation. We anticipate that this review will serve as a valuable reference for researchers seeking to leverage novel metabolic intervention-matched immunomodulators in macrophages or other fields of immune engineering.

Proximity-Enhanced Functional Imaging Analysis of Engineered Tumors

Functional imaging (FI) techniques have revolutionized tumor imaging by providing information on specific tumor functions, such as glycometabolism. However, tumor cells lack unique molecular characteristics at the molecular level and metabolic pathways, resulting in limited metabolic differences compared to normal cells and increased background signals from FI. To address this limitation, we developed a novel imaging technique termed proximity-enhanced functional imaging (PEFI) for accurate visualization of tumors. By using "two adjacent chemically labeled glycoproteins" as output signals, we significantly enhance the metabolic differences between tumor and normal cells by PEFI, thereby reducing the background signals for analysis and improving the accuracy of tumor functional imaging. Our results demonstrate that PEFI can accurately identify tumors at the cellular, tissue, and animal level, and has potential value in clinical identification and analysis of tumor cells and tissues, as well as in the guidance of clinical tumor resection surgery.

Sorafenib and tetrakis (4-carboxyphenyl) porphyrin assembled nanoparticles for synergistic targeted chemotherapy and sonodynamic therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is characterized by a high degree of malignancy and mortality. Sorafenib (SOR), a multi-kinase inhibitor, is clinically used in the treatment of HCC. However, SOR suffers from serious side effects and drug resistance. The development of novel therapeutic strategies for HCC therapy is urgently needed. Sonodynamic therapy (SDT) has unique advantages in treating deep tumors due to the merits of deep tissue penetration, low side effects, and the absence of drug resistance. Here, we developed multifunctional nanoparticles (NPs) termed SOR-TCPP@PEG-FA by assembling SOR, tetrakis (4-carboxyphenyl) porphyrin (TCPP), and folic acid (FA)-modified DSPE-PEG. The FA group enhances the tumor targeting capability of these NPs, while TCPP generates ROS under ultrasound (US) irradiation, which are toxic to tumor cells, and SOR with chemotherapeutic effects is released, thus realizing the synergistic SDT and chemotherapy of tumors.

Red blood cell membrane-coated functionalized Cu-doped metal organic framework nanoformulations as a biomimetic platform for improved chemo-/chemodynamic/photothermal synergistic therapy

Nanoformulations for combining chemotherapy, chemodynamic therapy, and photothermal therapy have enormous potential in tumor treatment. Coating nanoformulations with cell membranes endows them with homologous cellular mimicry, enabling nanoformulations to acquire new functions and properties, including homologous targeting and long circulation in vivo, and can enhance internalization by homologous cancer cells. Herein, we fused multifunctional biomimetic nanoformulations based on Cu-doped zeolitic imidazolate framework-8 (ZIF-8). Hydroxycamptothecin (HCPT), a clinical anti-tumor drug, was encapsulated into ZIF-8, which was subsequently coated with polydopamine (PDA) and red blood cell membrane. The as-fabricated biomimetic nanoformulations showed an enhanced cell uptake in vitro and the potential to prolong blood circulation in vivo, producing effective synergistic chemotherapy, chemodynamic therapy, and photothermal therapy under the 808 nm laser irradiation. Together, the biomimetic nanoformulations showed a prolonged blood circulation and evasion of immune recognition in vivo to provide a bio-inspired strategy which may have the potential for the multi-synergistic therapy of breast cancer.

Dual-Mode Nanoprobes Based on Lanthanide Doped Fluoride Nanoparticles Functionalized by Aryl Diazonium Salts for Fluorescence and SERS Bioimaging

The design of dual-mode fluorescence and Raman tags stimulates a growing interest in biomedical imaging and sensing applications as they offer the possibility to synergistically combine the versatility and velocity of fluorescence imaging with the specificity of Raman spectroscopy. Although lanthanide-doped fluoride nanoparticles (NPs) are among the most studied fluorescent nanoprobes, their use for the development of bimodal fluorescent-Raman probes has never been reported yet, to the best of the authors knowledge, probably due to the difficulty to functionalize them with Raman reporter groups. This gap is filled herein by proposing a fast and straightforward approach based on aryl diazonium salt chemistry to functionalize Eu3+ or Tb3+ doped CaF2 and LaF3 NPs by Raman scatters. The resulting surface-enhanced Raman spectroscopy (SERS)-encoded lanthanide-doped fluoride NPs retain their fluorescence labeling capacity and display efficient SERS activity for cell bioimaging. The potential of this new generation of bimodal nanoprobes is assessed through cell viability assays and intracellular fluorescence and Raman imaging, opening up unprecedented opportunities for biomedical applications.

Introducing Specific Iodine Ions in Perovskite-Based Nanocomplex to Cater for Versatile Biomedical Imaging and Tumor Radiotherapy

Multimodal biomedical imaging and imaging-guided therapy have garnered extensive attention owing to the aid of nanoagents with the aim of further improving the therapeutic efficacy of diseases. The ability to engineer nanocomplexes (NCs) or control how they behave within an organism remains largely elusive. Here, a multifunctional nanoplatform is developed based on stabilized I-doped perovskite, CsPbBr3 -x Ix @SiO2 @Lip-c(RGD)2 (PSL-c(RGD)2 ) NCs. In particular, by regulating the amount of regular I- ions introduced, the fluorescence emission spectrum of perovskite-based NCs can be modulated well to match the requirement for biomedical optical imaging at the scale from molecule, cell to mouse; doping 125 I enables the nanoformulation to be competent for single-photon emission computed tomography (SPECT) imaging; the introduction of 131 I- imparts the NCs with the capability for radiotherapy. Through facile manipulation of specific iodine ions, this nanoplatform exhibits a remarkable ability to match multifunctional biomedical imaging and tumor therapy. In addition, their in vivo behavior can be manipulated by adjusting the thickness of the silica shell and the surface polarity for more practical applications. These experimental explorations offer a novel approach for engineering desirable multimodal NCs to simultaneously image and combat malignant tumors.

Protease-Mediated T1 Contrast Enhancement of Multilayered Magneto-Gadolinium Nanostructures for Imaging and Magnetic Hyperthermia

In this work, we constructed a multifunctional composite nanostructure for combined magnetic hyperthermia therapy and magnetic resonance imaging based on T1 and T2 signals. First, iron oxide nanocubes with a benchmark heating efficiency for magnetic hyperthermia were assembled within an amphiphilic polymer to form magnetic nanobeads. Next, poly(acrylic acid)-coated inorganic sodium gadolinium fluoride nanoparticles were electrostatically loaded onto the magnetic nanobead surface via a layer-by-layer approach by employing a positively charged enzymatic-cleavable biopolymer. The positive-negative multilayering process was validated through the changes occurring in surface ζ-potential values and structural characterization by transmission electron microscopy (TEM) imaging. These nanostructures exhibit an efficient heating profile, in terms of the specific absorption rates under clinically accepted magnetic field conditions. The addition of protease enzyme mediates the degradation of the surface layers of the nanostructures with the detachment of gadolinium nanoparticles from the magnetic beads and exposure to the aqueous environment. Such a process is associated with changes in the T1 relaxation time and contrast and a parallel decrease in the T2 signal. These structures are also nontoxic when tested on glioblastoma tumor cells up to a maximum gadolinium dose of 125 μg mL-1, which also corresponds to a iron dose of 52 μg mL-1. Nontoxic nanostructures with such enzyme-triggered release mechanisms and T1 signal enhancement are desirable for tracking tumor microenvironment release with remote T1-guidance and magnetic hyperthermia therapy actuation to be done at the diseased site upon verification of magnetic resonance imaging (MRI)-guided release.

Modular Self-Assembling Dendrimer Nanosystems for Magnetic Resonance and Multimodality Imaging of Tumors

Bioimaging is a powerful tool for diagnosing tumors but remains limited in terms of sensitivity and specificity. Nanotechnology-based imaging probes able to accommodate abundant imaging units with different imaging modalities are particularly promising for overcoming these limitations. In addition, the nanosized imaging agents can specifically increase the contrast of tumors by exploiting the enhanced permeability and retention effect. A proof-of-concept study is performed on pancreatic cancer to demonstrate the use of modular amphiphilic dendrimer-based nanoprobes for magnetic resonance (MR) imaging (MRI) or MR/near-infrared fluorescence (NIRF) multimodality imaging. Specifically, the self-assembly of an amphiphilic dendrimer bearing multiple Gd3+ units at its terminals, generates a nanomicellar agent exhibiting favorable relaxivity for MRI with a good safety profile. MRI reveals an up to two-fold higher contrast enhancement in tumors than in normal muscle. Encapsulating the NIRF dye within the core of the nanoprobe yields an MR/NIRF bimodal imaging agent for tumor detection that is efficient both for MRI, at Gd3+ concentrations 1/10 the standard clinical dose, and for NIRF imaging, allowing over two-fold stronger fluorescence intensities. These self-assembling dendrimer nanosystems thus constitute effective probes for MRI and MR/NIRF multimodality imaging, offering a promising nanotechnology platform for elaborating multimodality imaging probes in biomedical applications.

Aggregation-Induced Emission-Armored Living Bacteriophage-DNA Nanobioconjugates for Targeting, Imaging, and Efficient Elimination of Intracellular Bacterial Infection

Intracellular bacterial infections bring a considerable risk to human life and health due to their capability to elude immune defenses and exhibit significant drug resistance. As a result, confronting and managing these infections present substantial challenges. In this study, we developed a multifunctional living phage nanoconjugate by integrating aggregation-induced emission luminogen (AIEgen) photosensitizers and nucleic acids onto a bacteriophage framework (forming MS2-DNA-AIEgen bioconjugates). These nanoconjugates can rapidly penetrate mammalian cells and specifically identify intracellular bacteria while concurrently producing a detectable fluorescent signal. By harnessing the photodynamic property of AIEgen photosensitizer and the bacteriophage's inherent targeting and lysis capability, the intracellular bacteria can be effectively eliminated and the activity of the infected cells can be restored. Moreover, our engineered phage nanoconjugates were able to expedite the healing process in bacterially infected wounds observed in diabetic mice models while simultaneously enhancing immune activity within infected cells and in vivo, without displaying noticeable toxicity. We envision that these multifunctional phage nanoconjugates, which utilize AIEgen photosensitizers and spherical nucleic acids, may present a groundbreaking strategy for combating intracellular bacteria and offer powerful avenues for theranostic applications in intracellular bacterial infection-associated diseases.

Polydopamine Nanostructure-Enhanced Water Interaction with pH-Responsive Manganese Sulfide Nanoclusters for Tumor Magnetic Resonance Contrast Enhancement and Synergistic Ferroptosis-Photothermal Therapy

Rational structure design benefits the development of efficient nanoplatforms for tumor theranostic application. In this work, a multifunctional polydopamine (PDA)-coated manganese sulfide (MnS) nanocluster was prepared. The polyhydroxy structure of PDA enhanced the water interaction with pH-responsive MnS nanoclusters via hydrogen bonds. At pH 5.5 conditions, the spin-lattice relaxation rate of MnS nanoclusters dramatically increased from 5.76 to 19.33 mM-1·s-1 after the PDA coating, which can be beneficial for efficient tumor magnetic resonance imaging. In addition, PDA endowed MnS nanoclusters with excellent biocompatibility and good photothermal conversion efficiency, which can be used for efficient tumor photothermal therapy (PTT). Furthermore, MnS nanoclusters possess the ability to release H2S in the acidic tumor microenvironment, effectively inhibiting mitochondrial respiration and adenosine triphosphate production. As a result, the expression of heat shock protein was obviously reduced, which can reduce the resistance of tumor cells to photothermal stimulation and enhance the efficacy of PTT. The released Mn2+ also displayed efficient peroxidase and glutathione oxidase-like activity, effectively inducing tumor cell ferroptosis and apoptosis at the same time. Therefore, this nanoplatform could be a potential nanotheranostic for magnetic resonance contrast enhancement and synergistic ferroptosis-PTT of tumors.

Nanocrystals for Deep-Tissue In Vivo Luminescence Imaging in the Near-Infrared Region

In vivo imaging technologies have emerged as a powerful tool for both fundamental research and clinical practice. In particular, luminescence imaging in the tissue-transparent near-infrared (NIR, 700-1700 nm) region offers tremendous potential for visualizing biological architectures and pathophysiological events in living subjects with deep tissue penetration and high imaging contrast owing to the reduced light-tissue interactions of absorption, scattering, and autofluorescence. The distinctive quantum effects of nanocrystals have been harnessed to achieve exceptional photophysical properties, establishing them as a promising category of luminescent probes. In this comprehensive review, the interactions between light and biological tissues, as well as the advantages of NIR light for in vivo luminescence imaging, are initially elaborated. Subsequently, we focus on achieving deep tissue penetration and improved imaging contrast by optimizing the performance of nanocrystal fluorophores. The ingenious design strategies of NIR nanocrystal probes are discussed, along with their respective biomedical applications in versatile in vivo luminescence imaging modalities. Finally, thought-provoking reflections on the challenges and prospects for future clinical translation of nanocrystal-based in vivo luminescence imaging in the NIR region are wisely provided.

Graphene-wrapped petal-like gap-enhanced Raman tags for enhancing photothermal conversion and Raman imaging

Multifunctional nanoplatform that combine imaging, diagnostic, and therapeutic functions into a single agent have great significance for the early diagnosis and efficient treatment of diseases, particularly tumors. In this study, we report on a novel graphene-wrapped petal-like gap-enhanced Raman tags with mesoporous silica shells (MS-GP-GERTs). These MS-GP-GERTs have 4-NBT Raman reporters embedded in the gap between the gold nanocore and the petal-shaped shell and are wrapped in graphene and mesoporous silica. The results of photothermal measurement experiments show that graphene layers significantly enhanced the photothermal effect of gap-enhanced Raman tags (GERTs). The photothermal conversion efficiency of MS-GP-GERTs reaches 40.8%, comparable to pure graphene. Moreover, MS-GP-GERTs show good photothermal performance in agarose phantoms, heating the phantom to 47 °C within 5 min under a low power density laser (0.5 W/cm2). MS-GP-GERTs also exhibit excellent photothermal stability and physiological environment stability, making them a promising candidate for repeated photothermal therapy. Raman spectra and mapping imaging experiments demonstrate MS-GP-GERTs' low detection limit (100 fM), large imaging depth (2.74 mm), and excellent ability to image simulated biological tissue and cells. This novel Raman tag has the potential to become a multifunctional nano platform for integrating Raman imaging diagnosis and photothermal therapy.

Semiconducting Polymers for Cancer Immunotherapy

As a monumental breakthrough in cancer treatment, immunotherapy has attracted tremendous attention in recent years. However, one challenge faced by immunotherapy is the low response rate and the immune-related adverse events (irAEs). Therefore, it is important to explore new therapeutic strategies and platforms for boosting therapeutic benefits and decreasing the side effects of immunotherapy. In recent years, semiconducting polymer (SP), a category of organic materials with π-conjugated aromatic backbone, has been attracting considerable attention because of their outstanding characteristics such as excellent photophysical features, good biosafety, adjustable chemical flexibility, easy fabrication, and high stability. With these distinct advantages, SP is extensively explored for bioimaging and photo- or ultrasound-activated tumor therapy. Here, the recent advancements in SP-based nanomedicines are summarized for enhanced tumor immunotherapy. According to the photophysical properties of SPs, the cancer immunotherapies enabled by SPs with the photothermal, photodynamic, or sonodynamic functions are highlighted in detail, with a particular focus on the construction of combination immunotherapy and activatable nanoplatforms to maximize the benefits of cancer immunotherapy. Herein, new guidance and comprehensive insights are provided for the design of SPs with desired photophysical properties to realize maximized effectiveness of required biomedical applications.

177 Lu Radiolabelled AIE Dots for Multimodal Imaging Guided Photothermal/Radiopharmaceutical Tumor Therapy

Aggregation-induced emission luminogens (AIEgens) in the second near-infrared region (NIR-II,1000-1700 nm) have shown tremendous potential as theragnostic probe for tumor multimodal diagnostic imaging and combined treatment owing to their programmable optical, structural and functional properties. Herein, we presented a radionuclide 177 Lu-labeled AIEgen, 177 Lu-2TT-oC6B dots, for NIR-II fluorescence and SPECT/CT imaging-guided tumor photothermal and radiopharmaceutical therapy. Intriguingly, 177 Lu-2TT-oC6B self-assembled into 10 nm dots, exhibited high NIR-II fluorescence quantum yield (QY, 1.34 %) and unprecedented photothermal conversion efficiency (PCE, 70.3 %) in vitro, furtherly performed extremely long blood circulation (T1/2 =52.4 h), persistent tumor accumulation and retention in tumor (NIR-II SNR=5.56; SPECT SNR=36.59) via intravenous administration in vivo. Furthermore, upon NIR light activation and 177 Lu irradiation, 177 Lu-2TT-oC6B demonstrated great application potential in synergistic photothermal/radiopharmaceutical tumor therapy.

Biomedical Approach of Nanotechnology and Biological Risks: A Mini-Review

Nanotechnology has played a prominent role in biomedical engineering, offering innovative approaches to numerous treatments. Notable advances have been observed in the development of medical devices, contributing to the advancement of modern medicine. This article briefly discusses key applications of nanotechnology in tissue engineering, controlled drug release systems, biosensors and monitoring, and imaging and diagnosis. The particular emphasis on this theme will result in a better understanding, selection, and technical approach to nanomaterials for biomedical purposes, including biological risks, security, and biocompatibility criteria.

Nanotechnology development in surgical applications: recent trends and developments

This paper gives a detailed analysis of nanotechnology's rising involvement in numerous surgical fields. We investigate the use of nanotechnology in orthopedic surgery, neurosurgery, plastic surgery, surgical oncology, heart surgery, vascular surgery, ophthalmic surgery, thoracic surgery, and minimally invasive surgery. The paper details how nanotechnology helps with arthroplasty, chondrogenesis, tissue regeneration, wound healing, and more. It also discusses the employment of nanomaterials in implant surfaces, bone grafting, and breast implants, among other things. The article also explores various nanotechnology uses, including stem cell-incorporated nano scaffolds, nano-surgery, hemostasis, nerve healing, nanorobots, and diagnostic applications. The ethical and safety implications of using nanotechnology in surgery are also addressed. The future possibilities of nanotechnology are investigated, pointing to a possible route for improved patient outcomes. The essay finishes with a comment on nanotechnology's transformational influence in surgical applications and its promise for future breakthroughs.

Advances in photoacoustic imaging aided by nano contrast agents: special focus on role of lymphatic system imaging for cancer theranostics

Photoacoustic imaging (PAI) is a successful clinical imaging platform for management of cancer and other health conditions that has seen significant progress in the past decade. However, clinical translation of PAI based methods are still under scrutiny as the imaging quality and clinical information derived from PA images are not on par with other imaging methods. Hence, to improve PAI, exogenous contrast agents, in the form of nanomaterials, are being used to achieve better image with less side effects, lower accumulation, and improved target specificity. Nanomedicine has become inevitable in cancer management, as it contributes at every stage from diagnosis to therapy, surgery, and even in the postoperative care and surveillance for recurrence. Nanocontrast agents for PAI have been developed and are being explored for early and improved cancer diagnosis. The systemic stability and target specificity of the nanomaterials to render its theranostic property depends on various influencing factors such as the administration route and physico-chemical responsiveness. The recent focus in PAI is on targeting the lymphatic system and nodes for cancer diagnosis, as they play a vital role in cancer progression and metastasis. This review aims to discuss the clinical advancements of PAI using nanoparticles as exogenous contrast agents for cancer theranostics with emphasis on PAI of lymphatic system for diagnosis, cancer progression, metastasis, PAI guided tumor resection, and finally PAI guided drug delivery.

Glycerol-weighted chemical exchange saturation transfer nanoprobes allow 19F/1H dual-modality magnetic resonance imaging-guided cancer radiotherapy

Recently, radiotherapy (RT) has entered a new realm of precision cancer therapy with the introduction of magnetic resonance (MR) imaging guided radiotherapy systems into the clinic. Nonetheless, identifying an optimized radiotherapy time window (ORTW) is still critical for the best therapeutic efficacy of RT. Here we describe pH and O2 dual-sensitive, perfluorooctylbromide (PFOB)-based and glycerol-weighted chemical exchange saturation transfer (CEST) nano-molecular imaging probes (Gly-PFOBs) with dual fluorine and hydrogen proton based CEST MR imaging properties (19F/1H-CEST). Oxygenated Gly-PFOBs ameliorate tumor hypoxia and improve O2-dependent radiotherapy. Moreover, the pH and O2 dual-sensitive properties of Gly-PFOBs could be quantitatively, spatially, and temporally monitored by 19F/1H-CEST imaging to optimize ORTW. In this study, we describe the CEST signal characteristics exhibited by the glycerol components of Gly-PFOBs. The pH and O2 dual-sensitive Gly-PFOBs with19F/1H-CEST MR dual-modality imaging properties, with superior therapeutic efficacy and biosafety, are employed for sensitive imaging-guided lung cancer RT, illustrating the potential of multi-functional imaging to noninvasively monitor and enhance RT-integrated effectiveness.

Design of Water-Soluble Rotaxane-Capped Superparamagnetic, Ultrasmall Fe3O4 Nanoparticles for Targeted NIR Fluorescence Imaging in Combination with Magnetic Resonance Imaging

Integrating an NIR fluorescent probe with a magnetic resonance imaging (MRI) agent to harvest complementary imaging information is challenging. Here, we have designed water-soluble, biocompatible, noncytotoxic, bright-NIR-emitting, sugar-functionalized, mechanically interlocked molecules (MIMs)-capped superparamagnetic ultrasmall Fe3O4 NPs for targeted multimodal imaging. Dual-functional stoppers containing an unsymmetrical NIR squaraine dye interlocked within a macrocycle to construct multifunctional MIMs are developed with enhanced NIR fluorescence efficiency and durability. One of the stoppers of the axle is composed of a lipophilic cationic TPP+ functionality to target mitochondria, and the other stopper comprises a dopamine-containing catechol group to anchor at the surface of the synthesized Fe3O4 NPs. Fe3O4 NPs surface-coated with targeted NIR rotaxanes help to deliver ultrasmall magnetic NPs specifically inside the mitochondria. Two carbohydrate moieties are conjugated with the macrocycle of the rotaxane via click chemistry to improve the water solubility of MitoSQRot-(Carb-OH)2-DOPA-Fe3O4 NPs. Water-soluble, rotaxane-capped Fe3O4 NPs are used for live-cell mitochondria-targeted NIR fluorescence confocal imaging, 3D and multicolor imaging in combination with T2-weighted MRI on a 9.4 T MR scanner with a high relaxation rate (r2) of 180.7 mM-1 s-1. Biocompatible, noncytotoxic, ultrabright NIR rotaxane-capped superparamagnetic ultrasmall monodisperse Fe3O4 NPs could be a promising agent for targeted multimodal imaging applications.

Engineered NIR-II fluorophores with ultralong-distance molecular packing for high-contrast deep lesion identification

The limited signal of long-wavelength near-infrared-II (NIR-II, 900-1880 nm) fluorophores and the strong background caused by the diffused photons make high-contrast fluorescence imaging in vivo with deep tissue disturbed still challenging. Here, we develop NIR-II fluorescent small molecules with aggregation-induced emission properties, high brightness, and maximal emission beyond 1200 nm by enhancing electron-donating ability and reducing the donor-acceptor (D-A) distance, to complement the scarce bright long-wavelength emissive organic dyes. The convincing single-crystal evidence of D-A-D molecular structure reveals the strong inhibition of the π-π stacking with ultralong molecular packing distance exceeding 8 Å. The delicately-designed nanofluorophores with bright fluorescent signals extending to 1900 nm match the background-suppressed imaging window, enabling the signal-to-background ratio of the tissue image to reach over 100 with the tissue thickness of ~4-6 mm. In addition, the intraluminal lesions with strong negatively stained can be identified with almost zero background. This method can provide new avenues for future long-wavelength NIR-II molecular design and biomedical imaging of deep and highly scattering tissues.

Stimuli-Responsive Design of Metal-Organic Frameworks for Cancer Theranostics: Current Challenges and Future Perspective

Scientific fraternity revealed the potential of stimuli-responsive nanotherapeutics for cancer treatment that aids in tackling the major restrictions of traditionally reported drug delivery systems. Among stimuli-responsive inorganic nanomaterials, metal-organic frameworks (MOFs) have transpired as unique porous materials displaying resilient structures and diverse applications in cancer theranostics. Mainly, it demonstrates tailorable porosity, versatile chemical configuration, tunable size and shape, and feasible surface functionalization, etc. The present review provides insights into the design of stimuli-responsive multifunctional MOFs for targeted drug delivery and bioimaging for effective cancer therapy. Initially, the concept of cancer, traditional cancer treatment, background of MOFs, and approaches for MOFs synthesis have been discussed. After this, applications of stimuli-responsive multifunctional MOFs-assisted nanostructures that include pH, light, ions, temperature, magnetic, redox, ATP, and others for targeted drug delivery and bioimaging in cancer have been thoroughly discussed. As an outcome, the designed multifunctional MOFs showed an alteration in properties due to the exogenous and endogenous stimuli that are beneficial for drug release and bioimaging. The several reported types of stimuli-responsive surface-modified MOFs revealed good biocompatibility to normal cells, promising drug loading capability, target-specific delivery of anticancer drugs into cancerous cells, etc. Despite substantial progress in this field, certain crucial issues need to be addressed to reap the clinical benefits of multifunctional MOFs. Specifically, the toxicological compatibility and biodegradability of the building blocks of MOFs demand a thorough evaluation. Moreover, the investigation of sustainable and greener synthesis methods is of the utmost importance. Also, the low flexibility, off-target accumulation, and compromised pharmacokinetic profile of stimuli-responsive MOFs have attracted keen attention. In conclusion, the surface-modified nanosized design of inorganic diverse stimuli-sensitive MOFs demonstrated great potential for targeted drug delivery and bioimaging in different kinds of cancers. In the future, the preference for stimuli-triggered MOFs will open a new frontier for cancer theranostic applications.

Functionalization of and through Melanin: Strategies and Bio-Applications

A unique feature of nanoparticles for bio-application is the ease of achieving multi-functionality through covalent and non-covalent functionalization. In this way, multiple therapeutic actions, including chemical, photothermal and photodynamic activity, can be combined with different bio-imaging modalities, such as magnetic resonance, photoacoustic, and fluorescence imaging, in a theragnostic approach. In this context, melanin-related nanomaterials possess unique features since they are intrinsically biocompatible and, due to their optical and electronic properties, are themselves very efficient photothermal agents, efficient antioxidants, and photoacoustic contrast agents. Moreover, these materials present a unique versatility of functionalization, which makes them ideal for the design of multifunctional platforms for nanomedicine integrating new functions such as drug delivery and controlled release, gene therapy, or contrast ability in magnetic resonance and fluorescence imaging. In this review, the most relevant and recent examples of melanin-based multi-functionalized nanosystems are discussed, highlighting the different methods of functionalization and, in particular, distinguishing pre-functionalization and post-functionalization. In the meantime, the properties of melanin coatings employable for the functionalization of a variety of material substrates are also briefly introduced, especially in order to explain the origin of the versatility of melanin functionalization. In the final part, the most relevant critical issues related to melanin functionalization that may arise during the design of multifunctional melanin-like nanoplatforms for nanomedicine and bio-application are listed and discussed.

NIR-II Imaging and Sandwiched Plasmonic Biosensor for Ultrasensitive Intraoperative Definition of Tumor-Invaded Lymph Nodes

Radical lymphadenectomy remains the cornerstone of preventing tumor metastasis through the lymphatic system. Current surgical resection of lymph nodes (LNs) based on fluorescence-guided surgery (FGS) suffers from low sensitivity/selectivity with only qualitative information, hampering accurate intraoperative decision-making. Herein, we develop a modularized theranostic system including NIR-II FGS and a sandwiched plasmonic chip (SPC). Intraoperative NIR-II FGS and detection of tumor-positive lymph nodes were performed on the gastric tumor to determine the feasibility of the modularized theranostic system in defining LN metastasis. Under the NIR-II imaging window, the orthotopic tumor and sentinel lymph nodes (SLNs) were successfully excised without ambient light interference in the operating room. Importantly, the SPC biosensor achieved 100% sensitivity and 100% specificity for tumor markers and realized rapid and high-throughput intraoperative SLN detection. We propose the synergetic design of combining the NIR-II FGS and suitable biosensor will substantially improve the efficiency of cancer diagnosis and therapy follow-up.

Smart One-for-All Agent with Adaptive Functions for Improving Photoacoustic /Fluorescence Imaging-Guided Photodynamic Immunotherapy

Multifunctional phototheranostics that integrate several diagnostic and therapeutic strategies into one platform hold great promise for precision medicine. However, it is really difficult for one molecule to possess multimodality optical imaging and therapy properties that all functions are in the optimized mode because the absorbed photoenergy is fixed. Herein, a smart one-for-all nanoagent that the photophysical energy transformation processes can be facilely tuned by external light stimuli is developed for precise multifunctional image-guided therapy. A dithienylethene-based molecule is designed and synthesized because it has two light-switchable forms. In the ring-closed form, most of the absorbed energy dissipates via nonradiative thermal deactivation for photoacoustic (PA) imaging. In the ring-open form, the molecule possesses obvious aggregation-induced emission features with excellent fluorescence and photodynamic therapy properties. In vivo experiments demonstrate that preoperative PA and fluorescence imaging help to delineate tumors in a high-contrast manner, and intraoperative fluorescence imaging is able to sensitively detect tiny residual tumors. Furthermore, the nanoagent can induce immunogenic cell death to elicit antitumor immunity and significantly suppress solid tumors. This work develops a smart one-for-all agent that the photophysical energy transformation and related phototheranostic properties can be optimized by light-driven structure switch, which is promising for multifunctional biomedical applications.

In situ orderly self-assembly strategy affording NIR-II-J-aggregates for in vivo imaging and surgical navigation

J-aggregation, an effective strategy to extend wavelength, has been considered as a promising method for constructing NIR-II fluorophores. However, due to weak intermolecular interactions, conventional J-aggregates are easily decomposed into monomers in the biological environment. Although adding external carriers could help conventional J-aggregates stabilize, such methods still suffer from high-concentration dependence and are unsuitable for activatable probes design. Besides, these carriers-assisted nanoparticles are risky of disassembly in lipophilic environment. Herein, by fusing the precipitated dye (HPQ) which has orderly self-assembly structure, onto simple hemi-cyanine conjugated system, we construct a series of activatable, high-stability NIR-II-J-aggregates which overcome conventional J-aggregates carrier's dependence and could in situ self-assembly in vivo. Further, we employ the NIR-II-J-aggregates probe HPQ-Zzh-B to achieve the long-term in situ imaging of tumor and precise tumor resection by NIR-II imaging navigation for reducing lung metastasis. We believe this strategy will advance the development of controllable NIR-II-J-aggregates and precise bioimaging in vivo.

Emerging ultrasmall luminescent nanoprobes for in vivo bioimaging

Photoluminescence (PL) imaging has become a fundamental tool in disease diagnosis, therapeutic evaluation, and surgical navigation applications. However, it remains a big challenge to engineer nanoprobes for high-efficiency in vivo imaging and clinical translation. Recent years have witnessed increasing research efforts devoted into engineering sub-10 nm ultrasmall nanoprobes for in vivo PL imaging, which offer the advantages of efficient body clearance, desired clinical translation potential, and high imaging signal-to-noise ratio. In this review, we present a comprehensive summary and contrastive discussion of emerging ultrasmall luminescent nanoprobes towards in vivo PL bioimaging of diseases. We first summarize size-dependent nano-bio interactions and imaging features, illustrating the unique attributes and advantages/disadvantages of ultrasmall nanoprobes differentiating them from molecular and large-sized probes. We also discuss general design methodologies and PL properties of emerging ultrasmall luminescent nanoprobes, which are established based on quantum dots, metal nanoclusters, lanthanide-doped nanoparticles, and silicon nanoparticles. Then, recent advances of ultrasmall luminescent nanoprobes are highlighted by surveying their latest in vivo PL imaging applications. Finally, we discuss existing challenges in this exciting field and propose some strategies to improve in vivo PL bioimaging and further propel their clinical applications.

Polydopamine nanomotors loaded indocyanine green and ferric ion for photothermal and photodynamic synergistic therapy of tumor

The limited penetration depth of nanodrugs in the tumor and the severe hypoxia inside the tumor significantly reduce the efficacy of photothermal-photodynamic synergistic therapy (PTT-PDT). Here, we synthesized a methoxypolyethylene glycol amine (mPEG-NH₂)-modified walnut-shaped polydopamine nanomotor (PDA-PEG) driven by near-infrared light (NIR). At the same time, it also loaded the photosensitizer indocyanine green (ICG) via electrostatic/hydrophobicinteractions and chelated with ferric ion (Fe³⁺). Under the irradiation of NIR, the asymmetry of PDA-PEG morphology led to the asymmetry of local photothermal effects and the formation of thermal gradient, which can make the nanomotor move autonomously. This ability of autonomous movement was proved to be used to improve the permeability of the nanomotor in three-dimensional (3D) tumor sphere. Fe³⁺ can catalyze endogenous hydrogen peroxide to produce oxygen, so as to overcome the hypoxia of tumor microenvironment and thereby generate more singlet oxygen to kill tumor cells. Animal experiments in vivo confirmed that the nanomotors had a good PTT-PDT synergistic treatment effect. The introduction of nanomotor technology has brought new ideas for cancer optical therapy.

Novel strategies for tumor radiosensitization mediated by multifunctional gold-based nanomaterials

Radiotherapy (RT) is one of the most effective and commonly used cancer treatments for malignant tumors. However, the existing radiosensitizers have a lot of side effects and poor efficacy, which limits the curative effect and further application of radiotherapy. In recent years, emerging nanomaterials have shown unique advantages in enhancing radiosensitization. In particular, gold-based nanomaterials, with high X-ray attenuation capacity, good biocompatibility, and promising chemical, electronic and optical properties, have become a new type of radiotherapy sensitizer. In addition, gold-based nanomaterials can be used as a carrier to load a variety of drugs and immunosuppressants; in particular, its photothermal therapy, photodynamic therapy and multi-mode imaging functions aid in providing excellent therapeutic effect in coordination with RT. Recently, many novel strategies of radiosensitization mediated by multifunctional gold-based nanomaterials have been reported, which provides a new idea for improving the efficacy and reducing the side effects of RT. In this review, we systematically summarize the recent progress of various new gold-based nanomaterials that mediate radiosensitization and describe the mechanism. We further discuss the challenges and prospects in the field. It is hoped that this review will help researchers understand the latest progress of gold-based nanomaterials for radiosensitization, and encourage people to optimize the existing methods or explore novel approaches for radiotherapy.

Knowledge domain and dynamic patterns in multimodal molecular imaging from 2012 to 2021: A visual bibliometric analysis

Multimodal molecular imaging technologies have been widely used to optimize medical research and clinical practice. Bibliometric analysis was performed to identify global research trends, hot spots, and scientific frontiers of multimodal molecular imaging technology from 2012 to 2021. The articles and reviews related to multimodal molecular imaging were retrieved from the Web of Science Core Collection. A bibliometric study was performed using CiteSpace and VOSviewer. A total of 4169 articles and reviews from 2012 to 2021 were analyzed. An increasing trend in the number of articles on multimodal molecular imaging technology was observed. These publications mainly come from 417 institutions in 92 countries, led by the USA and China. K. Bailey Freund published the most papers amongst the publications, while R.F. Spaide had the most co-citations. A dual map overlay of the literature shows that most publications were specialized in physics/materials/chemistry, and molecular/biology/immunology. Synergistic therapy in cancer, advanced nanotechnology, and multimodal imaging in ophthalmology are new trends and developing areas of interest. A global bibliometric and visualization analysis was used to comprehensively review the published research related to multimodal molecular imaging. This study may help in understanding the dynamic patterns of multimodal molecular imaging technology research and point out the developing areas of this field.

Four-Photon Absorption Iron Complex for Magnetic Resonance/Photoacoustic Dual-Model Imaging and an Enhanced Ferroptosis Process

Four-photon absorption (4PA) multimodal therapeutic agent applied to tumor ferroptosis process tracking is rarely reported. In this paper, two functionalized terpyridine iron complexes (TD-FeCl₃, TD-Fe-TD) with four-photon absorption properties were designed and synthesized. The four-photon absorption cross sections of TD-FeCl₃ reached 6.87 × 10^-74cm⁸·s³·photon^-3. Due to its strong near-infrared absorption, TD-FeCl₃ has excellent photoacoustic imaging (PAI) capability for accurate PA imaging. TD-FeCl₃ has an efficient longitudinal electron relaxation rate (r₁ = 2.26 mM^-1 s^-1) and high spatial resolution, which can be applied as T₁-weighted magnetic resonance imaging (MRI) contrast agent for tumor imaging in vivo. In addition, Fe³⁺ as a natural ferroptosis tracer, TD-FeCl₃, is able to deplete glutathione (GSH) effectively, which can further enhance the ferroptosis process. We found that the series of cheap transition metal complexes has four-photon absorption activity and can be used as multimodal (MRI/PAI) diagnostic agents for tumor tracing processes.