Tumor microenvironment enhanced NIR II fluorescence imaging for tumor precise surgery navigation via tetrasulfide mesoporous silica-coated Nd-based rare-earth nanocrystals

Molecular Gold Nanoclusters for Advanced NIR-II Bioimaging and Therapy

Small thiolate-protected gold molecular clusters have gained significant interest in research due to their unique size-dependent properties. Their molecular to nanoscale sizes lead to distinctive quantum confinement effects, resulting in a discrete electronic energy band gap structure and molecule-like properties, including HOMO-LUMO electronic transitions, enhanced photoluminescence, and intrinsic magnetism and chirality. Near-infrared II (NIR-II, 1000-3000 nm) emissive gold clusters have emerged as a fascinating class of nanomaterials that are well-suited for biomedical applications. The unique combination of stability, biocompatibility, and tunable emission properties position them as valuable tools for high-resolution and deep-tissue imaging, with potential real-world applications ranging from disease diagnostics and prognosis to therapeutics. In this review, we focus on the NIR-II photoluminescence properties of gold molecular clusters for preclinical in vivo NIR-II imaging of vasculature, brain, kidney, liver, and gastrointestinal organs, and molecular targeted tumor imaging and theranostic treatment. The imaging capabilities combined with fast excretion and a high safety profile make molecular gold clusters highly promising for clinical translation.

A promising mesoporous silica carrier material for the diagnosis and treatment of liver diseases: recent research advances

The therapeutic diagnosis of liver diseases has garnered significant interest within the medical community. In recent years, mesoporous silica nanoparticles (MSNs) have emerged as crucial nanocarriers for the treatment of liver ailments. Their remarkable diagnostic capabilities enable them to be used in techniques such as high-throughput mass spectrometry (MS), magnetic resonance imaging (MRI), near-infrared (NIR) fluorescence imaging, photoacoustic imaging (PAI), and ultrasonography (US), attracting considerable attention. Furthermore, the introduction of amino and carboxyl group modifications in MSNs has facilitated their use as drug delivery carriers for treating liver diseases, including hepatocellular carcinoma. This paper reviews the preparation methods, in vitro diagnostic capabilities, and in vivo therapeutic delivery systems of MSNs for liver disease treatment. It also summarizes relevant toxicity studies, aiming to provide a comprehensive overview of the diagnostic and therapeutic applications of MSNs in the treatment of liver diseases, particularly hepatocellular carcinoma. Through this review, we seek to offer theoretical insights into the potential of MSNs for diagnostic and therapeutic applications in liver disease treatment.

Applications of nanotheranostics in the second near-infrared window in bioimaging and cancer treatment

Achieving accurate and efficient tumor imaging is crucial in the field of tumor treatment, as it facilitates early detection and precise localization of tumor tissues, thereby informing therapeutic strategies and surgical interventions. The optical imaging technology within the second near-infrared (NIR-II) window has garnered significant interest for its remarkable benefits, such as enhanced tissue penetration depth, superior signal-to-background ratio (SBR), minimal tissue autofluorescence, reduced photon attenuation, and lower tissue scattering. This review explained the design and optimization strategies of nano-agents responsive to the NIR-II window, such as single-walled carbon nanotubes, quantum dots, lanthanum-based nanomaterials, and noble metal nanomaterials. These nano-agents enable non-invasive, deep-tissue imaging with high spatial resolution in the NIR-II window, and their superior optical properties significantly improve the accuracy, efficiency, and versatility of imaging-guided tumor treatments. And we discussed the characteristics and advantages of fluorescence imaging (FL)/photoacoustic imaging (PA) in NIR-II window, providing a comprehensive overview of the latest research progress of different nano-agents in FL/PA imaging-guided tumor therapy. Furthermore, we exhaustively reviewed the latest applications of multifunctional nano-phototherapy technologies carried out by NIR-II light including photothermal therapy (PTT), photodynamic therapy (PDT), and combined modalities like photothermal-chemodynamic therapy (PTT-CDT), photothermal-chemotherapy (PTT-CT), and photothermal- immunotherapy (PTT-IO). These imaging-guided integrated tumor therapy approaches within the NIR-II window have gradually matured over the past decade and are expected to become a safe and effective non-invasive tumor treatment. Finally, we outlined the prospects and challenges of development and innovation of the NIR-II integrated diagnosis and therapy nanoplatform. This review aims to provide insightful perspectives for future advancements in NIR-II optical tumor diagnosis and integrated treatment platforms.

Enhancing antitumor immunity with stimulus-responsive mesoporous silicon in combination with chemotherapy and photothermal therapy

Due to the immunosuppressive tumor microenvironment (TME) and potential systemic toxicity, chemotherapy often fails to elicit satisfactory anti-tumor responses, so how to activate anti-tumor immunity to improve the therapeutic efficacy remains a challenging problem. Photothermal therapy (PTT) serves as a promising approach to activate anti-tumor immunity by inducing the release of tumor neoantigens in situ. In this study, we designed tetrasulfide bonded mesoporous silicon nanoparticles (MSNs) loaded with the traditional drug doxorubicin (DOX) inside and modified their outer layer with polydopamine (DOX/MSN-4S@PDA) for comprehensive anti-tumor studies in vivo and in vitro. The MSN core contains GSH-sensitive tetrasulfide bonds that enhance DOX release while generating hydrogen sulfide (H2S) to improve the therapeutic efficacy of DOX. The polydopamine (PDA) coating confers acid sensitivity and mild photothermal properties upon exposure to near-infrared (NIR) light, while the addition of hyaluronic acid (HA) to the outermost layer enables targeted delivery to CD44-expressing tumor cells, thereby enhancing drug accumulation at the tumor site and reducing toxic side effects. Our studies demonstrate that DOX/MSN@PDA-HA can reverse the immunosuppressive tumor microenvironment in vivo, inducing potent immunogenic cell death (ICD) of tumor cells and improving anti-tumor efficacy. In addition, DOX/MSN@PDA-HA significantly suppresses tumor metastasis to the lung and liver. In summary, DOX/MSN@PDA-HA exhibits controlled drug release, excellent biocompatibility, and remarkable tumor inhibition capabilities through synergistic chemical/photothermal combined therapy.

Progress of Mesoporous Silica Coated Gold Nanorods for Biological Imaging and Cancer Therapy

For unique surface plasmon absorption and fluorescence characteristics, gold nanorods have been developed and widely employed in the biomedical field. However, limitations still exist due their low specific surface area, instability and tendency agglomerate in cytoplasm. Mesoporous silica materials have been broadly applied in field of catalysts, adsorbents, nanoreactors, and drug carriers due to its unique mesoporous structure, highly comparative surface area, good stability and biocompatibility. Therefore, coating gold nanorods with a dendritic mesopore channels can effectively prevent particle agglomeration, while increasing the specific surface area and drug loading efficiency. This review discusses the advancements of GNR@MSN in synthetic process, bio-imaging technique and tumor therapy. Additionally, the further application of GNR@MSN in imaging-guided treatment modalities is explored, while its promising superior application prospect is highlighted. Finally, the issues related to in vivo studies are critically examined for facilitating the transition of this promising nanoplatform into clinical trials.

"All in one" nanoprobe Au-TTF-1 for target FL/CT bioimaging, machine learning technology and imaging-guided photothermal therapy against lung adenocarcinoma

The accurate preoperative diagnosis and tracking of lung adenocarcinoma is hindered by non-targeting and diffusion of dyes used for marking tumors. Hence, there is an urgent need to develop a practical nanoprobe for tracing lung adenocarcinoma precisely even treating them noninvasively. Herein, Gold nanoclusters (AuNCs) conjugate with thyroid transcription factor-1 (TTF-1) antibody, then multifunctional nanoprobe Au-TTF-1 is designed and synthesized, which underscores the paramount importance of advancing the machine learning diagnosis and bioimaging-guided treatment of lung adenocarcinoma. Bright fluorescence (FL) and strong CT signal of Au-TTF-1 set the stage for tracking. Furthermore, the high specificity of TTF-1 antibody facilitates selective targeting of lung adenocarcinoma cells as compared to common lung epithelial cells, so machine learning software Lung adenocarcinoma auxiliary detection system was designed, which combined with Au-TTF-1 to assist the intelligent recognition of lung adenocarcinoma jointly. Besides, Au-TTF-1 not only contributes to intuitive and targeted visualization, but also guides the following noninvasive photothermal treatment. The boundaries of tumor are light up by Au-TTF-1 for navigation, it penetrates into tumor and implements noninvasive photothermal treatment, resulting in ablating tumors in vivo locally. Above all, Au-TTF-1 serves as a key platform for target bio-imaging navigation, machine learning diagnosis and synergistic PTT as a single nanoprobe, which demonstrates attractive performance on lung adenocarcinoma.

Multifunctional mesoporous silica nanoparticles for biomedical applications

Mesoporous silica nanoparticles (MSNs) are recognized as a prime example of nanotechnology applied in the biomedical field, due to their easily tunable structure and composition, diverse surface functionalization properties, and excellent biocompatibility. Over the past two decades, researchers have developed a wide variety of MSNs-based nanoplatforms through careful design and controlled preparation techniques, demonstrating their adaptability to various biomedical application scenarios. With the continuous breakthroughs of MSNs in the fields of biosensing, disease diagnosis and treatment, tissue engineering, etc., MSNs are gradually moving from basic research to clinical trials. In this review, we provide a detailed summary of MSNs in the biomedical field, beginning with a comprehensive overview of their development history. We then discuss the types of MSNs-based nanostructured architectures, as well as the classification of MSNs-based nanocomposites according to the elements existed in various inorganic functional components. Subsequently, we summarize the primary purposes of surface-functionalized modifications of MSNs. In the following, we discuss the biomedical applications of MSNs, and highlight the MSNs-based targeted therapeutic modalities currently developed. Given the importance of clinical translation, we also summarize the progress of MSNs in clinical trials. Finally, we take a perspective on the future direction and remaining challenges of MSNs in the biomedical field.

Luminescent Gold Nanoclusters for Bioimaging: Increasing the Ligand Complexity

Fluorescence, and more in general, photoluminescence (PL), presents important advantages for imaging with respect to other diagnostic techniques. In particular, detection methodologies exploiting fluorescence imaging are fast and versatile; make use of low-cost and simple instrumentations; and are taking advantage of newly developed powerful, low-cost, light-based electronic devices, such as light sources and cameras, used in huge market applications, such as civil illumination, computers, and cellular phones. Besides the aforementioned simplicity, fluorescence imaging offers a spatial and temporal resolution that can hardly be achieved with alternative methods. However, the two main limitations of fluorescence imaging for bio-application are still (i) the biological tissue transparency and autofluorescence and (ii) the biocompatibility of the contrast agents. Luminescent gold nanoclusters (AuNCs), if properly designed, combine high biocompatibility with PL in the near-infrared region (NIR), where the biological tissues exhibit higher transparency and negligible autofluorescence. However, the stabilization of these AuNCs requires the use of specific ligands that also affect their PL properties. The nature of the ligand plays a fundamental role in the development and sequential application of PL AuNCs as probes for bioimaging. Considering the importance of this, in this review, the most relevant and recent papers on AuNCs-based bioimaging are presented and discussed highlighting the different functionalities achieved by increasing the complexity of the ligand structure.

Key Parameters for the Rational Design, Synthesis, and Functionalization of Biocompatible Mesoporous Silica Nanoparticles

Over the last few years, research on silica nanoparticles has rapidly increased. Particularly on mesoporous silica nanoparticles (MSNs), as nanocarriers for the treatment of various diseases because of their physicochemical properties and biocompatibility. The use of MSNs combined with therapeutic agents can provide better encapsulation and effective delivery. MSNs as nanocarriers might also be a promising tool to lower the therapeutic dosage levels and thereby to reduce undesired side effects. Researchers have explored several routes to conjugate both imaging and therapeutic agents onto MSNs, thus expanding their potential as theranostic platforms, in order to allow for the early diagnosis and treatment of diseases. This review introduces a general overview of recent advances in the field of silica nanoparticles. In particular, the review tackles the fundamental aspects of silicate materials, including a historical presentation to new silicates and then focusing on the key parameters that govern the tailored synthesis of functional MSNs. Finally, the biomedical applications of MSNs are briefly revised, along with their biocompatibility, biodistribution and degradation. This review aims to provide the reader with the tools for a rational design of biocompatible MSNs for their application in the biomedical field. Particular attention is paid to the role that the synthesis conditions have on the physicochemical properties of the resulting MSNs, which, in turn, will determine their pharmacological behavior. Several recent examples are highlighted to stress the potential that MSNs hold as drug delivery systems, for biomedical imaging, as vaccine adjuvants and as theragnostic agents.