Combining Augmented Radiotherapy and Immunotherapy through a Nano-Gold and Bacterial Outer-Membrane Vesicle Complex for the Treatment of Glioblastoma

A recent insight of applications of gold nanoparticles in glioblastoma multiforme therapy

The application of gold nanoparticles (AuNPs) in cancer therapy, particularly targeted therapy of glioblastoma multiforme (GBM), is an up-and-coming field of research that has gained much interest in recent years. GBM is a life-threatening malignant tumour of the brain that currently has a 95 % death rate with an average of 15 months of survival. AuNPs have proven to have wide clinical implications and compelling therapeutic potential in many researches, specifically in GBM treatment. It was found that the reason why AuNPs were highly desired for GBM treatment was due to their unique properties that diversified the applications of AuNPs further to include imaging, diagnosis, and photothermal therapy. These properties include easy synthesis, biocompatibility, and surface functionalization. Various studies also underscored the ability of AuNPs to cross the blood-brain-barrier and selectively target tumour cells while displaying no major safety concerns which resulted in better therapy results. We attempt to bring together some of these studies in this review and provide a comprehensive overview of safety evaluations and current and potential applications of AuNPs in GBM therapy that may result in AuNP-mediated therapy to be the new gold standard for GBM treatment.

Zinc-Modified Titanate Nanotubes as Radiosensitizers for Glioblastoma: Enhancing Radiotherapy Efficacy and Monte Carlo Simulations

Radiotherapy (RT) is the established noninvasive treatment for glioblastoma (GBM), a highly aggressive malignancy. However, its effectiveness in improving patient survival remains limited due to the radioresistant nature of GBM. Metal-based nanostructures have emerged as promising strategies to enhance RT efficacy. Among them, titanate nanotubes (TNTs) have gained significant attention due to their biocompatibility and cost-effectiveness. This study aimed to synthesize zinc-modified TNTs (ZnTNT) from sodium TNTs (NaTNT), in addition to characterizing the formed nanostructures and evaluating their radiosensitization effects in GBM cells (U87 and U251). Hydrothermal synthesis was employed to fabricate the TNTs, which were characterized using various techniques, including transmission electron microscopy (TEM), energy-dispersive spectroscopy, scanning-transmission mode, Fourier-transform infrared spectroscopy, ICP-MS (inductively coupled plasma mass spectrometry), X-ray photoelectron spectroscopy, and zeta potential analysis. Cytotoxicity was evaluated in healthy (Vero) and GBM (U87 and U251) cells by the MTT assay, while the internalization of TNTs was observed through TEM imaging and ICP-MS. The radiosensitivity of ZnTNT and NaTNT combined with 5 Gy was evaluated using clonogenic assays. Monte Carlo simulations using the MCNP6.2 code were performed to determine the deposited dose in the culture medium for RT scenarios involving TNT clusters and cells. The results demonstrated differences in the dose deposition values between the scenarios with and without TNTs. The study revealed that ZnTNT interfered with clonogenic integrity, suggesting its potential as a powerful tool for GBM treatment.

New insights into targeted therapy of glioblastoma using smart nanoparticles

In recent times, the intersection of nanotechnology and biomedical research has given rise to nanobiomedicine, a captivating realm that holds immense promise for revolutionizing diagnostic and therapeutic approaches in the field of cancer. This innovative fusion of biology, medicine, and nanotechnology aims to create diagnostic and therapeutic agents with enhanced safety and efficacy, particularly in the realm of theranostics for various malignancies. Diverse inorganic, organic, and hybrid organic-inorganic nanoparticles, each possessing unique properties, have been introduced into this domain. This review seeks to highlight the latest strides in targeted glioblastoma therapy by focusing on the application of inorganic smart nanoparticles. Beyond exploring the general role of nanotechnology in medical applications, this review delves into groundbreaking strategies for glioblastoma treatment, showcasing the potential of smart nanoparticles through in vitro studies, in vivo investigations, and ongoing clinical trials.

Nanomaterials as Microglia Modulators in the Treatment of Central Nervous System Disorders

Microglia play a pivotal role in the central nervous system (CNS) homeostasis, acting as housekeepers and defenders of the surrounding environment. These cells can elicit their functions by shifting into two main phenotypes: pro-inflammatory classical phenotype, M1, and anti-inflammatory alternative phenotype, M2. Despite their pivotal role in CNS homeostasis, microglia phenotypes can influence the development and progression of several CNS disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, ischemic stroke, traumatic brain injuries, and even brain cancer. It is thus clear that the possibility of modulating microglia activation has gained attention as a therapeutic tool against many CNS pathologies. Nanomaterials are an unprecedented tool for manipulating microglia responses, in particular, to specifically target microglia and elicit an in situ immunomodulation activity. This review focuses the discussion on two main aspects: analyzing the possibility of using nanomaterials to stimulate a pro-inflammatory response of microglia against brain cancer and introducing nanostructures able to foster an anti-inflammatory response for treating neurodegenerative disorders. The final aim is to stimulate the analysis of the development of new microglia nano-immunomodulators, paving the way for innovative and effective therapeutic approaches for the treatment of CNS disorders.

Unveiling clinical applications of bacterial extracellular vesicles as natural nanomaterials in disease diagnosis and therapeutics

Bacterial extracellular vesicles (BEVs) are naturally occurring bioactive membrane-bound nanoparticles released by both gram-negative and gram-positive bacterial species, exhibiting a multifaceted role in mediating host-microbe interactions across various physiological conditions. Increasing evidence supports BEVs as essential mediators of cell-to-cell communicaiton, influencing bacterial pathogenicity, disease mechanisms, and modulating the host immune response. However, the extent to which these BEV-mediated actions can be leveraged to predict disease onset, guide treatment strategies, and determine clinical outcomes remains uncertain, particularly in terms of their clinical translation potentials. This review briefly describes BEV biogenesis and their internalisation by recipient cells and summarises methods for isolation and characterization, essential for understanding their composition and cargo. Further, it discusses the potential of biofluid-associated BEVs as biomarkers for various diseases, spanning both cancer and non-cancerous conditions. Following this, we outline the ongoing human clinical trials of using BEVs for vaccine development. In addition to disease diagnostics, this review explores the emerging research of using natural or engineered BEVs as smart nanomaterials for applications in anti-cancer therapy and bone regeneration. This discussion extends to key factors for unlocking the clinical potential of BEVs, such as standardization of BEV isolation and characterisation, as well as other hurdles in translating these findings to the clinical setting. We propose that addressing these hurdles through collaborative research efforts and well-designed clinical trials holds the key to fully harnessing the clinical potential of BEVs. As this field advances, this review suggests that BEV-based nanomedicine has the potential to revolutionize disease management, paving the way for innovative diagnosis, therapeutics, and personalized medicine approaches. STATEMENT OF SIGNIFICANCE: Extracellular vesicles (EVs) from both host cells and bacteria serve as multifunctional biomaterials and are emerging in the fields of biomedicine, bioengineering, and biomaterials. However, the majority of current studies focus on host-derived EVs, leaving a gap in comprehensive research on bacteria-derived EVs (BEVs). Although BEVs offer an attractive option as nanomaterials for drug delivery systems, their unique nanostructure and easy-to-modify functions make them a potential method for disease diagnosis and treatment as well as vaccine development. Our work among the pioneering studies investigating the potential of BEVs as natural nanobiomaterials plays a crucial role in both understanding the development of diseases and therapeutic interventions.

Advances in Engineered Macrophages: A New Frontier in Cancer Immunotherapy

Macrophages, as pivotal cells within the tumour microenvironment, significantly influence the impact of and reactions to treatments for solid tumours. The rapid evolution of bioengineering technology has revealed the vast potential of engineered macrophages in immunotherapy, disease diagnosis, and tissue engineering. Given this landscape, the goal of harnessing and innovating macrophages as a novel strategy for solid tumour immunotherapy cannot be overstated. The diverse strategies for engineered macrophages in the realm of cancer immunotherapy, encompassing macrophage drug delivery systems, chimeric antigen receptor macrophage therapy, and synergistic treatment approaches involving bacterial outer membrane vesicles and macrophages, are meticulously examined in this review. These methodologies are designed to enhance the therapeutic efficacy of macrophages against solid tumours, particularly those that are drug-resistant and metastatic. Collectively, these immunotherapies are poised to supplement and refine current solid tumour treatment paradigms, thus heralding a new frontier in the fight against malignant tumours.

Engineered bacterial outer membrane vesicles: a versatile bacteria-based weapon against gastrointestinal tumors

Outer membrane vesicles (OMVs) are nanoscale lipid bilayer structures released by gram-negative bacteria. They share membrane composition and properties with their originating cells, making them adept at traversing cellular barriers. These OMVs have demonstrated exceptional membrane stability, immunogenicity, safety, penetration, and tumor-targeting properties, which have been leveraged in developing vaccines and drug delivery systems. Recent research efforts have focused on engineering OMVs to increase production yield, reduce cytotoxicity, and improve the safety and efficacy of treatment. Notably, gastrointestinal (GI) tumors have proven resistant to several traditional oncological treatment strategies, including chemotherapy, radiotherapy, and targeted therapy. Although immune checkpoint inhibitors have demonstrated efficacy in some patients, their usage as monotherapy remains limited by tumor heterogeneity and individual variability. The immunogenic and modifiable nature of OMVs makes them an ideal design platform for the individualized treatment of GI tumors. OMV-based therapy enables combination therapy and optimization of anti-tumor effects. This review comprehensively summarizes recent advances in OMV engineering for GI tumor therapy and discusses the challenges in the clinical translation of emerging OMV-based anti-tumor therapies.

Selenium-based metabolic oligosaccharide engineering strategy for quantitative glycan detection

Metabolic oligosaccharide engineering (MOE) is a classical chemical approach to perturb, profile and perceive glycans in physiological systems, but probes upon bioorthogonal reaction require accessibility and the background signal readout makes it challenging to achieve glycan quantification. Here we develop SeMOE, a selenium-based metabolic oligosaccharide engineering strategy that concisely combines elemental analysis and MOE,enabling the mass spectrometric imaging of glycome. We also demonstrate that the new-to-nature SeMOE probes allow for detection, quantitative measurement and visualization of glycans in diverse biological contexts. We also show that chemical reporters on conventional MOE can be integrated into a bifunctional SeMOE probe to provide multimodality signal readouts. SeMOE thus provides a convenient and simplified method to explore the glyco-world.

Engineered bacterial extracellular vesicles for central nervous system diseases

The prevalence of central nervous system (CNS) diseases is on the rise as the population ages. The presence of various obstacles, particularly the blood-brain barrier (BBB), poses a challenge for drug delivery to the CNS. An expanding body of study suggests that gut microbiota (GM) plays an important role in CNS diseases. The communication between GM and CNS diseases has received increasing attention. Accumulating evidence indicates that the GM can modulate host signaling pathways to regulate distant organ functions by delivering bioactive substances to host cells via bacterial extracellular vesicles (BEVs). BEVs have emerged as a promising platform for the treatment of CNS diseases due to their nanostructure, ability to penetrate the BBB, as well as their low toxicity, high biocompatibility, ease of modification and large-scale culture. Here, we discuss the biogenesis, internalization mechanism and engineering modification methods of BEVs. We then focus on the use and potential role of BEVs in the treatment of CNS diseases. Finally, we outline the main challenges and future prospects for the application of BEVs in CNS diseases. We hope that the comprehensive understanding of the BEVs-based gut-brain axis will provide new insights into the treatment of CNS diseases.

Bacterial outer membrane vesicles as drug delivery carrier for photodynamic anticancer therapy

Photodynamic Therapy (PDT) is an effective tumor treatment strategy that not only induces photocytotoxicity to kill tumor cells directly but also activates the immune system in the body to generate tumor-specific immunity, preventing cancer metastasis and recurrence. However, some limitations of PDT limit the therapeutic efficacy in deep tumors. Previous studies have used different types of nanoparticles (NPs) as drug carriers of photosensitizers (PSs) to overcome the shortcomings of PDT and improve therapeutic efficacy. Among them, bacterial outer membrane vesicles (OMVs) have natural advantages as carriers for PS delivery. In addition to the targeted delivery of PSs into tumor cells, their unique immunogenicity helps them to serve as immune adjuvants to enhance the PDT-induced immune effect, providing new ideas for photodynamic anticancer therapy. Therefore, in this review, we will introduce the biogenesis and anticancer functions of OMVs and the research on them as drug delivery carriers in PDT. Finally, we also discuss the challenges and prospects of OMVs as a versatile drug delivery carrier for photodynamic anticancer therapy.

The role of bacteria and its derived biomaterials in cancer radiotherapy

Bacteria-mediated anti-tumor therapy has received widespread attention due to its natural tumor-targeting ability and specific immune-activation characteristics. It has made significant progress in breaking the limitations of monotherapy and effectively eradicating tumors, especially when combined with traditional therapy, such as radiotherapy. According to their different biological characteristics, bacteria and their derivatives can not only improve the sensitivity of tumor radiotherapy but also protect normal tissues. Moreover, genetically engineered bacteria and bacteria-based biomaterials have further expanded the scope of their applications in radiotherapy. In this review, we have summarized relevant researches on the application of bacteria and its derivatives in radiotherapy in recent years, expounding that the bacteria, bacterial derivatives and bacteria-based biomaterials can not only directly enhance radiotherapy but also improve the anti-tumor effect by improving the tumor microenvironment (TME) and immune effects. Furthermore, some probiotics can also protect normal tissues and organs such as intestines from radiation via anti-inflammatory, anti-oxidation and apoptosis inhibition. In conclusion, the prospect of bacteria in radiotherapy will be very extensive, but its biological safety and mechanism need to be further evaluated and studied.

Neutrophil-Mediated Delivery of Nanocrystal Drugs via Photoinduced Inflammation Enhances Cancer Therapy

The efficient delivery of anticancer agents into tumor microenvironments is critical for the success of cancer therapies, but it is a prerequisite that drug carriers should overcome tumor vasculature and possess high drug contents. Here, we found that photoinduced inflammation response caused the migration of neutrophils into tumor microenvironments and neutrophils transported neutrophil-targeted nanoparticles (NPs) across the tumor blood barrier. The results showed that tumor delivery efficiencies of NPs were 5% ID/g, and they were independent of particle sizes (30-200 nm) and their doses (108-1011 NPs). To efficiently deliver anticancer agents into tumors via neutrophils, we fabricated carrier-free paclitaxel nanocrystals (PTX NC). The results showed that neutrophil uptake of PTX NC did not impair neutrophil tumor infiltration, and the sustainable release of PTX from PTX NC in tumors was regulated by paclitaxel protein complexes, thus improving the mouse survival in two preclinical models. Our studies demonstrate that delivery of nanocrystal drugs via neutrophils is a promising method to effectively treat a wide range of cancers, and we have also identified a mechanism of drug release from neutrophils in tumors.

Emerging therapeutic role of gut microbial extracellular vesicles in neurological disorders

Extracellular vesicles (EVs) serve as cell-to-cell and inter-organ communicators by conveying proteins and nucleic acids with regulatory functions. Emerging evidence shows that gut microbial-released EVs play a pivotal role in the gut-brain axis, bidirectional communication, and crosstalk between the gut and the brain. Increasing pre-clinical and clinical evidence suggests that gut bacteria-released EVs are capable of eliciting distinct signaling to the brain with the ability to cross the blood-brain barrier, exerting regulatory function on brain cells such as neurons, astrocytes, and microglia, via their abundant and diversified protein and nucleic acid cargo. Conversely, EVs derived from certain species of bacteria, particularly from gut commensals with probiotic properties, have recently been shown to confer distinct therapeutic effects on various neurological disorders. Thus, gut bacterial EVs may be both a cause of and therapy for neuropathological complications. This review marshals the basic, clinical, and translational studies that significantly contributed to our up-to-date knowledge of the therapeutic potential of gut microbial-derived EVs in treating neurological disorders, including strokes, Alzheimer's and Parkinson's disease, and dementia. The review also discusses the newer insights in recent studies focused on developing superior therapeutic microbial EVs via genetic manipulation and/or dietary intervention.

Mechanisms and applications of radiation-induced oxidative stress in regulating cancer immunotherapy

Radiotherapy (RT) is an effective treatment option for cancer patients, which induces the production of reactive oxygen species (ROS) and causes oxidative stress (OS), leading to the death of tumor cells. OS not only causes apoptosis, autophagy and ferroptosis, but also affects tumor immune response. The combination of RT and immunotherapy has revolutionized the management of various cancers. In this process, OS caused by ROS plays a critical role. Specifically, RT-induced ROS can promote the release of tumor-associated antigens (TAAs), regulate the infiltration and differentiation of immune cells, manipulate the expression of immune checkpoints, and change the tumor immune microenvironment (TME). In this review, we briefly summarize several ways in which IR induces tumor cell death and discuss the interrelationship between RT-induced OS and antitumor immunity, with a focus on the interaction of ferroptosis with immunogenic death. We also summarize the potential mechanisms by which ROS regulates immune checkpoint expression, immune cells activity, and differentiation. In addition, we conclude the therapeutic opportunity improving radiotherapy in combination with immunotherapy by regulating OS, which may be beneficial for clinical treatment.

Gold Nanoparticles: Construction for Drug Delivery and Application in Cancer Immunotherapy

Cancer immunotherapy is an innovative treatment strategy to enhance the ability of the immune system to recognize and eliminate cancer cells. However, dose limitations, low response rates, and adverse immune events pose significant challenges. To address these limitations, gold nanoparticles (AuNPs) have been explored as immunotherapeutic drug carriers owing to their stability, surface versatility, and excellent optical properties. This review provides an overview of the advanced synthesis routes for AuNPs and their utilization as drug carriers to improve precision therapies. The review also emphasises various aspects of AuNP-based immunotherapy, including drug loading, targeting strategies, and drug release mechanisms. The application of AuNPs combined with cancer immunotherapy and their therapeutic efficacy are briefly discussed. Overall, we aimed to provide a recent understanding of the advances, challenges, and prospects of AuNPs for anticancer applications.

Challenges and advances for glioma therapy based on inorganic nanoparticles

Glioma is one of the most serious central nervous system diseases, with high mortality and poor prognosis. Despite the continuous development of existing treatment methods, the median survival time of glioma patients is still only 15 months. The main treatment difficulties are the invasive growth of glioma and the obstruction of the blood-brain barrier (BBB) to drugs. With rapid advancements in nanotechnology, inorganic nanoparticles (INPs) have shown favourable application prospects in the diagnosis and treatment of glioma. Due to their extraordinary intrinsic features, INPs can be easily fabricated, while doping with other elements and surface modification by biological ligands can be used to enhance BBB penetration, targeted delivery and biocompatibility. Guided glioma theranostics with INPs can improve and enhance the efficacy of traditional methods such as chemotherapy, radiotherapy and gene therapy. New strategies, such as immunotherapy, photothermal and photodynamic therapy, magnetic hyperthermia therapy, and multifunctional inorganic nanoplatforms, have also been facilitated by INPs. This review emphasizes the current state of research and clinical applications of INPs, including glioma targeting and BBB penetration enhancement methods, in vivo and in vitro biocompatibility, and diagnostic and treatment strategies. As such, it provides insights for the development of novel glioma treatment strategies.

X-Ray Activatable Au/Ag Nanorods for Tumor Radioimmunotherapy Sensitization and Monitoring of the Therapeutic Response Using NIR-II Photoacoustic Imaging

Radioimmunotherapy (RIT) is an advanced physical therapy used to kill primary cancer cells and inhibit the growth of distant metastatic cancer cells. However, challenges remain because RIT generally has low efficacy and serious side effects, and its effects are difficult to monitor in vivo. This work reports that Au/Ag nanorods (NRs) enhance the effectiveness of RIT against cancer while allowing the therapeutic response to be monitored using activatable photoacoustic (PA) imaging in the second near-infrared region (NIR-II, 1000-1700 nm). The Au/Ag NRs can be etched using high-energy X-ray to release silver ions (Ag⁺ ), which promotes dendritic cell (DC) maturation, enhances T-cell activation and infiltration, and effectively inhibits primary and distant metastatic tumor growth. The survival time of metastatic tumor-bearing mice treated with Au/Ag NR-enhanced RIT is 39 days compared with 23 days in the PBS control group. Furthermore, the surface plasmon absorption intensity at 1040 nm increases fourfold after Ag⁺ are released from the Au/Ag NRs, allowing X-ray activatable NIR-II PA imaging to monitor the RIT response with a high signal-to-background ratio of 24.4. Au/Ag NR-based RIT has minimal side effects and shows great promise for precise cancer RIT.

Emerging Trends in Nano-Driven Immunotherapy for Treatment of Cancer

Despite advancements in the development of anticancer medications and therapies, cancer still has the greatest fatality rate due to a dismal prognosis. Traditional cancer therapies include chemotherapy, radiotherapy, and targeted therapy. The conventional treatments have a number of shortcomings, such as a lack of selectivity, non-specific cytotoxicity, suboptimal drug delivery to tumour locations, and multi-drug resistance, which results in a less potent/ineffective therapeutic outcome. Cancer immunotherapy is an emerging and promising strategy to elicit a pronounced immune response against cancer. Immunotherapy stimulates the immune system with cancer-specific antigens or immune checkpoint inhibitors to overcome the immune suppressive tumour microenvironment and kill the cancer cells. However, delivery of the antigen or immune checkpoint inhibitors and activation of the immune response need to circumvent the issues pertaining to short lifetimes and effect times, as well as adverse effects associated with off-targeting, suboptimal, or hyperactivation of the immune system. Additional challenges posed by the tumour suppressive microenvironment are less tumour immunogenicity and the inhibition of effector T cells. The evolution of nanotechnology in recent years has paved the way for improving treatment efficacy by facilitating site-specific and sustained delivery of the therapeutic moiety to elicit a robust immune response. The amenability of nanoparticles towards surface functionalization and tuneable physicochemical properties, size, shape, and surfaces charge have been successfully harnessed for immunotherapy, as well as combination therapy, against cancer. In this review, we have summarized the recent advancements made in choosing different nanomaterial combinations and their modifications made to enable their interaction with different molecular and cellular targets for efficient immunotherapy. This review also highlights recent trends in immunotherapy strategies to be used independently, as well as in combination, for the destruction of cancer cells, as well as prevent metastasis and recurrence.

The role of cell membrane-coated nanoparticles as a novel treatment approach in glioblastoma

Glioblastoma multiform (GBM) is the most prevalent and deadliest primary brain malignancy in adults, whose median survival rate does not exceed 15 months after diagnosis. The conventional treatment of GBM, including maximal safe surgery followed by chemotherapy and radiotherapy, usually cannot lead to notable improvements in the disease prognosis and the tumor always recurs. Many GBM characteristics make its treatment challenging. The most important ones are the impermeability of the blood-brain barrier (BBB), preventing chemotherapeutic drugs from reaching in adequate amounts to the tumor site, intratumoral heterogeneity, and roles of glioblastoma stem cells (GSCs). To overcome these barriers, the recently-developed drug-carrying approach using nanoparticles (NPs) may play a significant role. NPs are tiny particles, usually less than 100 nm showing various diagnostic and therapeutic medical applications. In this regard, cell membrane (CM)-coated NPs demonstrated several promising effects in GBM in pre-clinical studies. They benefit from fewer adverse effects due to their specific targeting of tumor cells, biocompatibility because of their CM surfaces, prolonged half-life, easy penetrating of the BBB, and escaping from the immune reaction, making them an attractive option for GBM treatment. To date, CM-coated NPs have been applied to enhance the effectiveness of major therapeutic approaches in GBM treatment, including chemotherapy, immunotherapy, gene therapy, and photo-based therapies. Despite the promising results in pre-clinical studies regarding the effectiveness of CM-coated NPs in GBM, significant barriers like high expenses, complex preparation processes, and unknown long-term effects still hinder its mass production for the clinic. In this regard, the current study aims to provide an overview of different characteristics of CM-coated NPs and comprehensively investigate their application as a novel treatment approach in GBM.

Nanomaterials for Drug Delivery and Cancer Therapy

In recent decades, the interest in nanomaterials has grown rapidly for their applications in many research fields, including drug delivery and cancer therapy [...].

Treatment of Brain Metastases: The Synergy of Radiotherapy and Immune Checkpoint Inhibitors

Brain metastases are a devastating sequela of common primary cancers (e.g., lung, breast, and skin) and have limited effective therapeutic options. Previously, systemic chemotherapy failed to demonstrate significant benefit in patients with brain metastases, but in recent decades, targeted therapies and more recently immune checkpoint inhibitors (ICIs) have yielded promising results in preclinical and clinical studies. Furthermore, there is significant interest in harnessing the immunomodulatory effects of radiotherapy (RT) to synergize with ICIs. Herein, we discuss studies evaluating the impact of RT dose and fractionation on the immune response, early studies supporting the synergistic interaction between RT and ICIs, and ongoing clinical trials assessing the benefit of combination therapy in patients with brain metastases.

NIR-II Absorptive Dithienopyrrole-Thiadiazolobenzotriazole Conjugated Polymer for Photoacoustic Imaging-Guided Glioblastoma Multiforme Photothermal Therapy

The development of new diagnostic imaging and precise treatment methods for glioblastoma multiforme (GBM) is significant to improve patients' quality of life and prolong their survival time. Herein, we proposed a photoacoustic imaging (PAI)-guided GBM high-efficient photothermal therapy (PTT) based on a second near-infrared (NIR-II) absorptive polymer (PDTP-TBZ) conjugated with intense electron donor dithienopyrrole (DTP) and strong electron acceptor thiadiazolobenzotriazole (TBZ). By nanoprecipitation, PDTP-TBZ can form into nanoparticles (PT NPs), and c(RGDfK) cyclic peptide with integrin-specific targeting was then modified on the surface of PT NPs to obtain the ability of active targeting GBM multifunctional nano-reagent (cRGD@PT NPs). Both in vitro and in vivo experiments demonstrated that cRGD@PT NPs as NIR-II GBM phototheranostic reagents can greatly improve the enrichment rate at tumor sites under PAI monitoring, and carry out precise NIR-II PTT with high effective tumor cell phototoxicity and high biological safety. Thus, cRGD@PT NPs have great potential for the future GBM phototheranostic application in clinic. STATEMENT OF SIGNIFICANCE: In this work, we successfully constructed an intense electron donor dithienopyrrole (DTP) with a strong electron acceptor thiadiazolobenzotriazole (TBZ) into a novel NIR-II optical absorptive conjugated polymer (PDTP-TBZ). Then, the c(RGDfK) cyclic peptide was modified on the surface of PT NPs to obtain multifunctional nanodiagnostic reagents (cRGD@PT NPs) that can effectively target GBM neovascularization and tumor cells. Both in vitro and in vivo experiments demonstrate that cRGD@PT NPs possess high photothermal conversion efficiency and practical photoacoustic imaging capability under 1064 nm laser irradiation. The results of this work suggested that cRGD@PT NPs have great potential in efficient NIR-II PTT guided by accurate PAI, which provide a good perspective for the treatment and diagnosis of GBM.

Nanotechnology-Based Combinatorial Anti-Glioblastoma Therapies: Moving from Terminal to Treatable

Aggressive glioblastoma (GBM) has no known treatment as a primary brain tumor. Since the cancer is so heterogeneous, an immunosuppressive tumor microenvironment (TME) exists, and the blood–brain barrier (BBB) prevents chemotherapeutic chemicals from reaching the central nervous system (CNS), therapeutic success for GBM has been restricted. Drug delivery based on nanocarriers and nanotechnology has the potential to be a handy tool in the continuing effort to combat the challenges of treating GBM. There are various new therapies being tested to extend survival time. Maximizing therapeutic effectiveness necessitates using many treatment modalities at once. In the fight against GBM, combination treatments outperform individual ones. Combination therapies may be enhanced by using nanotechnology-based delivery techniques. Nano-chemotherapy, nano-chemotherapy–radiation, nano-chemotherapy–phototherapy, and nano-chemotherapy–immunotherapy for GBM are the focus of the current review to shed light on the current status of innovative designs.

Bacterial extracellular vesicles as bioactive nanocarriers for drug delivery: Advances and perspectives

Nanosized extracellular vesicles derived from bacteria contain diverse cargo and transfer intercellular bioactive molecules to cells. Due to their favorable intercellular interactions, cell membrane-derived bacterial extracellular vesicles (BEVs) have great potential to become novel drug delivery platforms. In this review, we summarize the biogenesis mechanism and compositions of various BEVs. In addition, an overview of effective isolation and purification techniques of BEVs is provided. In particular, we focus on the application of BEVs as bioactive nanocarriers for drug delivery. Finally, we summarize the advances and challenges of BEVs after providing a comprehensive discussion in each section. We believe that a deeper understanding of BEVs will open new avenues for their exploitation in drug delivery applications.

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Bacterial extracellular vesicles (BEVs) are excellent nanomaterials as drug delivery systems.

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The unique nanosized structures and biofunctions of BEVs are attractive for their use as nanomedicine platforms.

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BEVs have been investigated as biotherapeutics due to their loading capacity, ease of modification and industrialization.

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This review provides new insights of BEVs in drug delivery applications, discussing potential opportunities and challenges.

Immunology Meets Bioengineering: Improving the Effectiveness of Glioblastoma Immunotherapy

Glioblastoma (GBM) therapy has seen little change over the past two decades. Surgical excision followed by radiation and chemotherapy is the current gold standard treatment. Immunotherapy techniques have recently transformed many cancer treatments, and GBM is now at the forefront of immunotherapy research. GBM immunotherapy prospects are reviewed here, with an emphasis on immune checkpoint inhibitors and oncolytic viruses. Various forms of nanomaterials to enhance immunotherapy effectiveness are also discussed. For GBM treatment and immunotherapy, we outline the specific properties of nanomaterials. In addition, we provide a short overview of several 3D (bio)printing techniques and their applications in stimulating the GBM microenvironment. Lastly, the susceptibility of GBM cancer cells to the various immunotherapy methods will be addressed.

Potential targets and treatments affect oxidative stress in gliomas: An overview of molecular mechanisms

Oxidative stress refers to the imbalance between oxidation and antioxidant activity in the body. Oxygen is reduced by electrons as part of normal metabolism leading to the formation of various reactive oxygen species (ROS). ROS are the main cause of oxidative stress and can be assessed through direct detection. Oxidative stress is a double-edged phenomenon in that it has protective mechanisms that help to destroy bacteria and pathogens, however, increased ROS accumulation can lead to host cell apoptosis and damage. Glioma is one of the most common malignant tumors of the central nervous system and is characterized by changes in the redox state. Therapeutic regimens still encounter multiple obstacles and challenges. Glioma occurrence is related to increased free radical levels and decreased antioxidant defense responses. Oxidative stress is particularly important in the pathogenesis of gliomas, indicating that antioxidant therapy may be a means of treating tumors. This review evaluates oxidative stress and its effects on gliomas, describes the potential targets and therapeutic drugs in detail, and clarifies the effects of radiotherapy and chemotherapy on oxidative stress. These data may provide a reference for the development of precise therapeutic regimes of gliomas based on oxidative stress.

Bacterial membrane vesicles for vaccine applications

Vaccines have been highly successful in the management of many diseases. However, there are still numerous illnesses, both infectious and noncommunicable, for which there are no clinically approved vaccine formulations. While there are unique difficulties that must be overcome in the case of each specific disease, there are also a number of common challenges that have to be addressed for effective vaccine development. In recent years, bacterial membrane vesicles (BMVs) have received increased attention as a potent and versatile vaccine platform. BMVs are inherently immunostimulatory and are able to activate both innate and adaptive immune responses. Additionally, BMVs can be readily taken up and processed by immune cells due to their nanoscale size. Finally, BMVs can be modified in a variety of ways, including by genetic engineering, cargo loading, and nanoparticle coating, in order to create multifunctional platforms that can be leveraged against different diseases. Here, an overview of the interactions between BMVs and immune cells is provided, followed by discussion on the applications of BMV vaccine nanotechnology against bacterial infections, viral infections, and cancers.

Size-changeable nanoprobes for the combined radiotherapy and photodynamic therapy of tumor

PURPOSE

Radiation therapy (RT) and photodynamic therapy (PDT) are promising while challenging in treating tumors. The potential radiation resistance of tumor cells and side effects to healthy tissues restrict their clinical treatment efficacy. Effective delivery of therapeutic agents to the deep tumor tissues would be available for tumor-accurate therapy and promising for the tumor therapy. Thus, developing nanoprobes with effectively delivering radiotherapy sensitizers and photosensitizers to the interior of tumors is needed for the accurate combined RT and PDT of tumor.

METHODS

The size-changeable nanoprobes of Gd₂O₃@BSA-BSA-Ce6 (BGBC) were synthesized with a crosslinking method. Magnetic resonance imaging (MRI) and in vivo near-infrared (NIR) imaging were measured to evaluate the nanoprobes' tumor accumulation and intratumor penetration effect. The tumor suppression effect of combined RT and PDT with these nanoprobes was also studied for the 4T1 bearing Balb/c mice.

RESULTS

The nanoprobes BGBC showed high tumor accumulation and disintegrated into small particles responding to the photo-irradiation-produced reactive oxygen species (ROS), allowing for tumor penetration. Abundant radiotherapy sensitizers and photosensitizers were delivered to the deep tumor tissues, which is available for the accurate therapy of tumor. In addition, the BGBC displayed outstanding MRI and fluorescence imaging effects for evaluating the biodistribution and tumor suppression effect of nanoprobes. Consequently, significant tumor suppression effect was obtained based on the accurate tumor treatment with the combined RT and PDT.

CONCLUSION

The designed size-changeable nanoprobes BGBC showed excellent tumor accumulation and deep tumor penetration, resulting in a significant tumor suppression effect based on the combined RT and PDT. This study provides a novel strategy for dual delivery of radiotherapy sensitizers and photosensitizers into the deep tumor tissues and is promising for the accurate theranostics of tumor.

Pharmacological Role of Functionalized Gold Nanoparticles in Disease Applications

Gold has always been regarded as a symbol of nobility, and its shiny golden appearance has always attracted the attention of many people. Gold has good ductility, molecular recognition properties, and good biocompatibility. At present, gold is being used in many fields. When gold particles are as small as several nanometers, their physical and chemical properties vary with their size in nanometers. The surface area of a nano-sized gold surface has a special effect. Therefore, gold nanoparticles can, directly and indirectly, give rise to different biological activities. For example, if the surface of the gold is sulfided. Various substances have a strong chemical reactivity and are easy to combine with sulfhydryl groups; hence, nanogold is often used in biomedical testing, disease diagnosis, and gene detection. Nanogold is easy to bind to proteins, such as antibodies, enzymes, or cytokines. In fact, scientists use nanogold to bind special antibodies, as a tool for targeting cancer cells. Gold nanoparticles are also directly cytotoxic to cancer cells. For diseases caused by inflammation and oxidative damage, gold nanoparticles also have antioxidant and anti-inflammatory effects. Based on these unique properties, gold nanoparticles have become the most widely studied metal nanomaterials. Many recent studies have further demonstrated that gold nanoparticles are beneficial for humans, due to their functional pharmacological properties in a variety of diseases. The content of this review will be the application of gold nanoparticles in treating or diagnosing pressing diseases, such as cancers, retinopathy, neurological diseases, skin disorders, bowel diseases, bone cartilage disorders, cardiovascular diseases, infections, and metabolic syndrome. Gold nanoparticles have shown very obvious therapeutic and application potential.

Radiotherapy for glioblastoma: clinical issues and nanotechnology strategies

Glioblastoma multiforme (GBM) is the most common primary brain cancer in adults with poor prognosis. Despite the current state of knowledge on its genetic characteristics, relatively little progress has been made in improving the treatment of patients with this fatal disease. Radiotherapy (RT) has been identified as a crucial treatment for GBM following surgical resection to improve both local control and survival. Unfortunately, radiotherapy resistance is frequently observed in GBM patients, which is the major reason for the high mortality rate of cancer patients. Radioresistance of GBM is often multifactorial and heterogeneous, and associated with the recurrence of GBM after surgery. Nanotechnology has gained increasing attention and has already been investigated for optimization of radiosensitization due to the unique properties of nanobiomaterials, such as photoelectric decay characteristics or potential as carriers for drug delivery to the central nervous system. A large body of preclinical data has accumulated over the past several years, in which nanotechnology-based strategies exhibit promising potential to enhance the radiosensitivity of GBM, both in cellular and animal models. In this review, we summarize the mechanisms of GBM radioresistance, including tumor cell-intrinsic factors as well as tumor microenvironment (TME). We further discuss current nano-biotechnology-based radiosensitizer in the treatment of GBM, summarize the latest findings, highlight challenges, and put forward prospects for the future of nano-radiosensitizers. These data suggest that nanotechnology has the potential to address many of the clinical challenges and nanobiomaterials would become promising next-generation radiotherapy sensitizers for GBM treatment.

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

Radiotherapy (RT), including external beam RT and internal radiation therapy, uses high-energy ionizing radiation to kill tumor cells.

Radiotherapy of High-Grade Gliomas: First Half of 2021 Update with Special Reference to Radiosensitization Studies

Albeit the effort to develop targeted therapies for patients with high-grade gliomas (WHO grades III and IV) is evidenced by hundreds of current clinical trials, radiation remains one of the few effective therapeutic options for them. This review article analyzes the updates on the topic "radiotherapy of high-grade gliomas" during the period 1 January 2021-30 June 2021. The high number of articles retrieved in PubMed using the search terms ("gliom* and radio*") and manually selected for relevance indicates the feverish research currently ongoing on the subject. During the last semester, significant advances were provided in both the preclinical and clinical settings concerning the diagnosis and prognosis of high-grade gliomas, their radioresistance, and the inevitable side effects of their treatment with radiation. The novel information concerning tumor radiosensitization was of special interest in terms of therapeutic perspective and was discussed in detail.