Vascular bursts enhance permeability of tumour blood vessels and improve nanoparticle delivery

Transvascular transport of nanocarriers for tumor delivery

Nanocarriers (NCs) play a crucial role in delivering theranostic agents to tumors, making them a pivotal focus of research. However, the persistently low delivery efficiency of engineered NCs has been a significant challenge in the advancement of nanomedicine, stirring considerable debate. Transvascular transport is a critical pathway for NC delivery from vessels to tumors, yet a comprehensive understanding of the interactions between NCs and vascular systems remains elusive. In recent years, considerable efforts have been invested in elucidating the transvascular transport mechanisms of NCs, leading to promising advancements in tumor delivery and theranostics. In this context, we highlight various delivery mechanisms, including the enhanced permeability and retention effect, cooperative immune-driven effect, active transcytosis, and cell/bacteria-mediated delivery. Furthermore, we explore corresponding strategies aimed at enhancing transvascular transport of NCs for efficient tumor delivery. These approaches offer intriguing solutions spanning physicochemical, biological, and pharmacological domains to improve delivery and therapeutic outcomes. Additionally, we propose a forward-looking delivery framework that relies on advanced tumor/vessel models, high-throughput NC libraries, nano-bio interaction datasets, and artificial intelligence, which aims to guide the design of next-generation carriers and implementation strategies for optimized delivery.

Gene-Engineered Cerium-Exosomes Mediate Atherosclerosis Therapy Through Remodeling of the Inflammatory Microenvironment and DNA Damage Repair

The pro-inflammatory immune microenvironment in the localized lesion areas and the absence of DNA damage repair mechanisms in endothelial cells serve as essential accelerating factors in the development of atherosclerosis. The lack of targeted therapeutic strategies represents a significant limitation in the efficacy of therapeutic agents for atherosclerosis. In this study, Genetically engineered SNHG12-loaded cerium-macrophage exosomes (Ce-Exo) are designed as atherosclerosis-targeting agents. In vivo studies demonstrated that Ce-Exo exhibited multivalent targeting properties for macrophages, with a 4.1-fold higher atherosclerotic plaque-aggregation ability than that of the control drugs. This suggests that Ce-Exo has a higher homing capacity and deeper penetration into the atherosclerotic plaque. In apolipoprotein E-deficient mice, Ce-Exo found to effectively remodel the immune microenvironment in the lesion area, repair endothelial cell damage, and inhibit the development of atherosclerosis. This study provides a novel approach to the treatment of atherosclerosis and demonstrates the potential of cell-derived drug carriers in biomedicine.

Nanoparticle Delivery to Tumours: From EPR and ATR Mechanisms to Clinical Impact

New insights into active versus passive nanoparticle tumour entry and exit mechanisms are enriching the understanding of tumour-targeted drug delivery. Here, we align the principles of the enhanced permeability and retention (EPR) and active transport and retention (ATR), and outline how their mechanistic features may be employed to improve the performance and clinical impact of cancer nanomedicines.

In Situ Formation of Fibronectin-Enriched Protein Corona on Epigenetic Nanocarrier for Enhanced Synthetic Lethal Therapy

PARP inhibitors (PARPi)-based synthetic lethal therapy demonstrates limited efficacy for most cancer types that are homologous recombination (HR) proficient. To potentiate the PARPi application, a nanocarrier based on 5-azacytidine (AZA)-conjugated polymer (PAZA) for the codelivery of AZA and a PARP inhibitor, BMN673 (BMN) is developed. AZA conjugation significantly decreased the nanoparticle (NP) size and increased BMN loading. Molecular dynamics simulation and experimental validations shed mechanistic insights into the self-assembly of effective NPs. The small PAZA NPs demonstrated higher efficiency of tumor targeting and penetration than larger NPs, which is mediated by a new mechanism of active targeting that involves the recruitment of fibronectin from serum proteins following systemic administration of PAZA NPs. Furthermore, it is found that PAZA carrier sensitize the HR-proficient nonsmall cell lung cancer (NSCLC) to BMN, a combination therapy that is more effective at a lower AZA/BMN dosage. To investigate the underlying mechanism, the tumor immune microenvironment and various gene expressions by RNAseq are explored. Moreover, the BMN/PAZA combination increased the immunogenicity and synergized with PD-1 antibody in improving the overall therapeutic effect in an orthotopic model of lung cancer (LLC).

Using imaging modalities to predict nanoparticle distribution and treatment efficacy in solid tumors: The growing role of ultrasound

Nanomedicine in oncology has not had the success in clinical impact that was anticipated in the early stages of the field's development. Ideally, nanomedicines selectively accumulate in tumor tissue and reduce systemic side effects compared to traditional chemotherapeutics. However, this has been more successful in preclinical animal models than in humans. The causes of this failure to translate may be related to the intra- and inter-patient heterogeneity of the tumor microenvironment. Predicting whether a patient will respond positively to treatment prior to its initiation, through evaluation of characteristics like nanoparticle extravasation and retention potential in the tumor, may be a way to improve nanomedicine success rate. While there are many potential strategies to accomplish this, prediction and patient stratification via noninvasive medical imaging may be the most efficient and specific strategy. There have been some preclinical and clinical advances in this area using MRI, CT, PET, and other modalities. An alternative approach that has not been studied as extensively is biomedical ultrasound, including techniques such as multiparametric contrast-enhanced ultrasound (mpCEUS), doppler, elastography, and super-resolution processing. Ultrasound is safe, inexpensive, noninvasive, and capable of imaging the entire tumor with high temporal and spatial resolution. In this work, we summarize the in vivo imaging tools that have been used to predict nanoparticle distribution and treatment efficacy in oncology. We emphasize ultrasound imaging and the recent developments in the field concerning CEUS. The successful implementation of an imaging strategy for prediction of nanoparticle accumulation in tumors could lead to increased clinical translation of nanomedicines, and subsequently, improved patient outcomes. This article is categorized under: Diagnostic Tools In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery Emerging Technologies.

Protein-based nanoparticles for therapeutic nucleic acid delivery

To realize the full potential of emerging nucleic acid therapies, there is a need for effective delivery agents to transport cargo to cells of interest. Protein materials exhibit several unique properties, including biodegradability, biocompatibility, ease of functionalization via recombinant and chemical modifications, among other features, which establish a promising basis for therapeutic nucleic acid delivery systems. In this review, we highlight progress made in the use of non-viral protein-based nanoparticles for nucleic acid delivery in vitro and in vivo, while elaborating on key physicochemical properties that have enabled the use of these materials for nanoparticle formulation and drug delivery. To conclude, we comment on the prospects and unresolved challenges associated with the translation of protein-based nucleic acid delivery systems for therapeutic applications.

Oxygen self-supplying small size magnetic nanoenzymes for synergistic photodynamic and catalytic therapy of breast cancer

In recent years, tumor catalytic therapy based on nanozymes has attracted widespread attention. However, its application is limited by the tumor hypoxic microenvironment (TME). In this study, we developed oxygen-supplying magnetic bead nanozymes that integrate hemoglobin and encapsulate the photosensitizer curcumin, demonstrating reactive oxygen species (ROS)-induced synergistic breast cancer therapy. Fe3O4 magnetic bead-mediated catalytic dynamic therapy (CDT) generates hydroxyl radicals (˙OH) through the Fenton reaction in the tumor microenvironment. The Hb-encapsulated Fe3O4 magnetic beads can be co-loaded with the photosensitizer/chemotherapeutic agent curcumin (cur), resulting in Fe3O4-Hb@cur. Under hypoxic conditions, oxygen molecules are released from Fe3O4-Hb@cur to overcome the TME hypoxia, resulting in comprehensive effects favoring anti-tumor responses. Upon near-infrared (NIR) irradiation, Fe3O4-Hb@cur activates the surrounding molecular oxygen to generate a certain amount of singlet oxygen (1O2), which is utilized for photodynamic therapy (PDT) in cancer treatment. Meanwhile, we validated that the O2 carried by Hb significantly enhances the intracellular ROS level, intensifying the catalytic therapy mediated by Fe3O4 magnetic beads and inflicting lethal damage to cancer cells, effectively inhibiting tumor growth. Therefore, significant in vivo synergistic therapeutic effects can be achieved through catalytic-photodynamic combination therapy.

Inertial migration of polymer micelles in a square microchannel

Using a hybrid simulation approach that combines a lattice-Boltzmann method for fluid flow and a molecular dynamics model for polymers, we investigate the inertial migration of star-like and crew-cut polymer micelles in a square microchannel. It is found that they exhibit two types of equilibrium positions, which shift further away from the center of the microchannel when the Reynolds number (Re) increases, as can be observed for soft particles. What differs from the behaviors of soft particles is that here, the blockage ratio is no longer the decisive factor. When the sizes are the same, the star-like micelles are always relatively closer to the microchannel wall as they gradually transition from spherical to disc-like with the increase of Re. In comparison, the crew-cut micelles are only transformed into an ellipsoid. Conversely, when the hydrophobic core sizes are the same, the equilibrium position of the star-like micelles becomes closer to that of the crew-cut micelles. Our results demonstrate that for polymer micelles with a core-shell structure, the equilibrium position is no longer solely determined by their overall dimensions but depends on the core and shell's specific dimensions, especially the hydrophobic core size. This finding opens up a new approach for achieving the separation of micelles in inertial migration.

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.

Nanomaterials-assisted photothermal therapy for breast cancer: State-of-the-art advances and future perspectives

Breast cancer (BC) remains an enigmatic fatal modality ubiquitously prevalent in different parts of the world. Contemporary medicines face severe challenges in remediating and healing breast cancer. Due to its spatial specificity and nominal invasive therapeutic regime, photothermal therapy (PTT) has attracted much scientific attention down the lane. PTT utilizes a near-infrared (NIR) light source to irradiate the tumor target intravenously or non-invasively, which is converted into heat energy over an optical fibre. Dynamic progress in nanomaterial synthesis was achieved with specialized visual, physicochemical, biological, and pharmacological features to make up for the inadequacies and expand the horizon of PTT. Numerous nanomaterials have substantial NIR absorption and can function as efficient photothermal transducers. It is achievable to limit the wavelength range of an absorbance peak for specific nanomaterials by manipulating their synthesis, enhancing the precision and quality of PTT. Along the same lines, various nanomaterials are conjugated with a wide range of surface-modifying chemicals, including polymers and antibodies, which may modify the persistence of the nanomaterial and diminish toxicity concerns. In this article, we tend to put forth specific insights and fundamental conceptualizations on pre-existing PTT and its advances upon conjugation with different biocompatible nanomaterials working in synergy to combat breast cancer, encompassing several strategies like immunotherapy, chemotherapy, photodynamic therapy, and radiotherapy coupled with PTT. Additionally, the role or mechanisms of nanoparticles, as well as possible alternatives to PTT, are summarized as a distinctive integral aspect in this article.

Nanoparticles Based on Natural Lipids Reveal Extent of Impacts of Designed Physical Characteristics on Biological Functions

Nanoparticles based on lipids (LNPs) are essential in pharmaceuticals and intercellular communication, and their design parameters span a diverse range of molecules and assemblies. In bridging the gap in insight between extracellular vesicles (EVs) and synthetic LNPs, one challenge is understanding their in-cell/in-body behavior when simultaneously assessing more than one physical characteristic. Herein, we demonstrate comprehensive evaluation of LNP behavior by using LNPs based on natural lipids (N-LNPs) with designed physical characteristics: size tuned using microfluidic methods, surface fluidity designed based on EV components, and stiffness tuned using biomolecules. We produce 12 types of N-LNPs having different physical characteristics─two sizes, three membrane fluidities, and two stiffnesses for in vitro evaluation─and evaluate cellular uptake vitality and endocytic pathways of N-LNPs based on the physical characteristics of N-LNPs. To reveal the extent of the impact of the predesigned physical characteristics of N-LNPs on cellular uptakes in vivo, we also carried out animal experiments with four types of N-LNPs having different sizes and fluidities. The use of N-LNPs has helped to clarify the extent of the impact of inextricably related, designed physical characteristics on transportation and provided a bidirectional guidepost for the streamlined design and understanding of the biological functions of LNPs.

Hypoxia and Singlet Oxygen Dual-Responsive Micelles for Photodynamic and Chemotherapy Therapy Featured with Enhanced Cellular Uptake and Triggered Cargo Delivery

Introduction

Combination therapy provides better outcomes than a single therapy and becomes an efficient strategy for cancer treatment. In this study, we designed a hypoxia- and singlet oxygen-responsive polymeric micelles which contain azo and nitroimidazole groups for enhanced cellular uptake, repaid cargo release, and codelivery of photosensitizer Ce6 and hypoxia-activated prodrug tirapazamine TPZ (DHM-Ce6@TPZ), which could be used for combining Ce6-mediated photodynamic therapy (PDT) and PDT-activated chemotherapy to enhance the therapy effect of cancer.

Methods

The hypoxia- and singlet oxygen-responsive polymeric micelles DHM-Ce6@TPZ were prepared by film hydration method. The morphology, physicochemical properties, stimuli responsiveness, in vitro singlet oxygen production, cellular uptake, and cell viability were evaluated. In addition, the in vivo therapeutic effects of the micelles were verified using a tumor xenograft mice model.

Results

The resulting dual-responsive micelles not only increased the concentration of intracellular photosensitizer and TPZ, but also facilitated photosensitizer and TPZ release for enhanced integration of photodynamic and chemotherapy therapy. As a photosensitizer, Ce6 induced PDT by generating toxic singlet reactive oxygen species (ROS), resulting in a hypoxic tumor environment to activate the prodrug TPZ to achieve efficient chemotherapy, thereby evoking a synergistic photodynamic and chemotherapy therapeutic effect. The cascade synergistic therapeutic effect of DHM-Ce6@TPZ was effectively evaluated both in vitro and in vivo to inhibit tumor growth in a breast cancer mice model.

Conclusion

The designed multifunctional micellar nano platform could be a convenient and powerful vehicle for the efficient co-delivery of photosensitizers and chemical drugs for enhanced synergistic photodynamic and chemotherapy therapeutic effect of cancer.

Breaking through the basement membrane barrier to improve nanotherapeutic delivery to tumours

An effective nanotherapeutic transport from the vasculature to the tumour is crucial for cancer treatment with minimal side effects. Here we demonstrate that, in addition to the endothelial barrier, the tumour vascular basement membrane surrounding the endothelium acts as a formidable mechanical barrier that entraps nanoparticles (NPs) in the subendothelial void, forming perivascular NP pools. Breaking through this basement membrane barrier substantially increases NP extravasation. Using inflammation triggered by local hyperthermia, we develop a cooperative immunodriven strategy to overcome the basement membrane barrier that leads to robust tumour killing. Hyperthermia-triggered accumulation and inflammation of platelets attract neutrophils to the NP pools. The subsequent movement of neutrophils through the basement membrane can release the NPs entrapped in the subendothelial void, resulting in increased NP penetration into deeper tumours. We show the necessity of considering the tumour vascular basement membrane barrier when delivering nanotherapeutics. Understanding this barrier will contribute to developing more effective antitumour therapies.

Stimuli-Responsive Nanoradiosensitizers for Enhanced Cancer Radiotherapy

Radiotherapy (RT) has been a classical therapeutic method of cancer for several decades. It attracts tremendous attention for the precise and efficient treatment of local tumors with stimuli-responsive nanomaterials, which enhance RT. However, there are few systematic reviews summarizing the newly emerging stimuli-responsive mechanisms and strategies used for tumor radio-sensitization. Hence, this review provides a comprehensive overview of recently reported studies on stimuli-responsive nanomaterials for radio-sensitization. It includes four different approaches for sensitized RT, namely endogenous response, exogenous response, dual stimuli-response, and multi stimuli-response. Endogenous response involves various stimuli such as pH, hypoxia, GSH, and reactive oxygen species (ROS), and enzymes. On the other hand, exogenous response encompasses X-ray, light, and ultrasound. Dual stimuli-response combines pH/enzyme, pH/ultrasound, and ROS/light. Lastly, multi stimuli-response involves the combination of pH/ROS/GSH and X-ray/ROS/GSH. By elaborating on these responsive mechanisms and applying them to clinical RT diagnosis and treatment, these methods can enhance radiosensitive efficiency and minimize damage to surrounding normal tissues. Finally, this review discusses the additional challenges and perspectives related to stimuli-responsive nanomaterials for tumor radio-sensitization.

Recent Progress and Challenges in Clinical Translation of Nanomedicines in Diagnosis and Treatment of Lung Cancer

Lung cancer is one of the leading causes of death across the world. There are numerous challenges in the early diagnosis and effective treatment of lung cancer, including developing multidrug resistance. However, the diagnosis of lung cancer could be minimally invasive or non-invasive. Nowadays, nanomedicines offer solutions to several emerging challenges in drug delivery research areas. It has the potential to enhance the therapeutic efficacy of biologically and chemically active agents at the site of action. This approach can also be employed in molecular and cellular imaging, precise and early detection, screening, and targeting drugs for lung cancer treatment. A proper understanding of the disease and timely diagnosis using strategically designed effective nanocarriers can be a promising approach to effectively managing cancer. The present review explores issues related to lung cancer chemotherapy and the promises and hurdles of newer approaches like nanomedicine. The article also summarizes the preclinical studies on diagnosis and treatment, pitfalls, and challenges in the clinical translation of nanomedicines for lung cancer therapy.

Stimuli-Responsive Polymer-Based Nanosystems for Cancer Theranostics

Stimuli-responsive polymers can respond to internal stimuli, such as reactive oxygen species (ROS), glutathione (GSH), and pH, biological stimuli, such as enzymes, and external stimuli, such as lasers and ultrasound, etc., by changing their hydrophobicity/hydrophilicity, degradability, ionizability, etc., and thus have been widely used in biomedical applications. Due to the characteristics of the tumor microenvironment (TME), stimuli-responsive polymers that cater specifically to the TME have been extensively used to prepare smart nanovehicles for the targeted delivery of therapeutic and diagnostic agents to tumor tissues. Compared to conventional drug delivery nanosystems, TME-responsive nanosystems have many advantages, such as high sensitivity, broad applicability among different tumors, functional versatility, and improved biosafety. In recent years, a great deal of research has been devoted to engineering efficient stimuli-responsive polymeric nanosystems, and significant improvement has been made to both cancer diagnosis and therapy. In this review, we summarize some recent research advances involving the use of stimuli-responsive polymer nanocarriers in drug delivery, tumor imaging, therapy, and theranostics. Various chemical stimuli will be described in the context of stimuli-responsive nanosystems. Accordingly, the functional chemical groups responsible for the responsiveness and the strategies to incorporate these groups into the polymer will be discussed in detail. With the research on this topic expending at a fast pace, some innovative concepts, such as sequential and cascade drug release, NIR-II imaging, and multifunctional formulations, have emerged as popular strategies for enhanced performance, which will also be included here with up-to-date illustrations. We hope that this review will offer valuable insights for the selection and optimization of stimuli-responsive polymers to help accelerate their future applications in cancer diagnosis and treatment.

Polypeptide-Based Systems: From Synthesis to Application in Drug Delivery

Synthetic polypeptides are biocompatible and biodegradable macromolecules whose composition and architecture can vary over a wide range. Their unique ability to form secondary structures, as well as different pathways of modification and biofunctionalization due to the diversity of amino acids, provide variation in the physicochemical and biological properties of polypeptide-containing materials. In this review article, we summarize the advances in the synthesis of polypeptides and their copolymers and the application of these systems for drug delivery in the form of (nano)particles or hydrogels. The issues, such as the diversity of polypeptide-containing (nano)particle types, the methods for their preparation and drug loading, as well as the influence of physicochemical characteristics on stability, degradability, cellular uptake, cytotoxicity, hemolysis, and immunogenicity of polypeptide-containing nanoparticles and their drug formulations, are comprehensively discussed. Finally, recent advances in the development of certain drug nanoformulations for peptides, proteins, gene delivery, cancer therapy, and antimicrobial and anti-inflammatory systems are summarized.

B7H3 targeting gold nanocage pH-sensitive conjugates for precise and synergistic chemo-photothermal therapy against NSCLC

BACKGROUND

The combination of drug delivery with immune checkpoint targeting has been extensively studied in cancer therapy. However, the clinical benefit for patients from this strategy is still limited. B7 homolog 3 protein (B7-H3), also known as CD276 (B7-H3/CD276), is a promising therapeutic target for anti-cancer treatment. It is widely overexpressed on the surface of malignant cells and tumor vasculature, and its overexpression is associated with poor prognosis. Herein, we report B7H3 targeting doxorubicin (Dox)-conjugated gold nanocages (B7H3/Dox@GNCs) with pH-responsive drug release as a selective, precise, and synergistic chemotherapy-photothermal therapy agent against non-small-cell lung cancer (NSCLC).

RESULTS

In vitro, B7H3/Dox@GNCs exhibited a responsive release of Dox in the tumor acidic microenvironment. We also demonstrated enhanced intracellular uptake, induced cell cycle arrest, and increased apoptosis in B7H3 overexpressing NSCLC cells. In xenograft tumor models, B7H3/Dox@GNCs exhibited tumor tissue targeting and sustained drug release in response to the acidic environment. Wherein they synchronously destroyed B7H3 positive tumor cells, tumor-associated vasculature, and stromal fibroblasts.

CONCLUSION

This study presents a dual-compartment targeted B7H3 multifunctional gold conjugate system that can precisely control Dox exposure in a spatio-temporal manner without evident toxicity and suggests a general strategy for synergistic therapy against NSCLC.

Skin cancer: understanding the journey of transformation from conventional to advanced treatment approaches

Skin cancer is a global threat to the healthcare system and is estimated to incline tremendously in the next 20 years, if not diagnosed at an early stage. Even though it is curable at an early stage, novel drug identification, clinical success, and drug resistance is another major challenge. To bridge the gap and bring effective treatment, it is important to understand the etiology of skin carcinoma, the mechanism of cell proliferation, factors affecting cell growth, and the mechanism of drug resistance. The current article focusses on understanding the structural diversity of skin cancers, treatments available till date including phytocompounds, chemotherapy, radiotherapy, photothermal therapy, surgery, combination therapy, molecular targets associated with cancer growth and metastasis, and special emphasis on nanotechnology-based approaches for downregulating the deleterious disease. A detailed analysis with respect to types of nanoparticles and their scope in overcoming multidrug resistance as well as associated clinical trials has been discussed.

Dendritic cell hybrid nanovaccine for mild heat inspired cancer immunotherapy

Cancer therapeutic vaccine can induce antigen-specific immune response, which has shown great potential in cancer immunotherapy. As the key factor of vaccine, antigen plays a central role in eliciting antitumor immunity. However, the insufficient antigen delivery and low efficiency of antigen presentation by dendritic cells (DCs) have greatly restricted the therapeutic efficiency of vaccine. Here we developed a kind of DC hybrid zinc phosphate nanoparticles to co-deliver antigenic peptide and photosensitive melanin. Owing to the chelating ability of Zn2+, the nanoparticles can co-encapsulate antigenic peptide and melanin with high efficiency. The nanovaccine showed good physiological stability with the hydration particle size was approximately 30 nm, and zeta potential was around - 10 mV. The nanovaccine showed homologous targeting effect to DCs in vivo and in vitro, efficiently delivering antigen to DCs. Meanwhile, the nanovaccine could effectively reflux to the tumor-draining lymph nodes. When combined with near-infrared irradiation, the nanovaccine induced effective mild heat in vitro and in vivo to promote antigen presentation. After administrating to MC38 tumor-bearing mice, the hybrid nanovaccine effectively promoted the maturation of DCs, the expansion of cytotoxic T lymphocytes and helper T cells, and the secretion of immunostimulatory cytokines, thereby significantly inhibiting tumor growth.

Current perspectives and trends in nanoparticle drug delivery systems in breast cancer: bibliometric analysis and review

The treatment of breast cancer (BC) is a serious challenge due to its heterogeneous nature, multidrug resistance (MDR), and limited therapeutic options. Nanoparticle-based drug delivery systems (NDDSs) represent a promising tool for overcoming toxicity and chemotherapy drug resistance in BC treatment. No bibliometric studies have yet been published on the research landscape of NDDS-based treatment of BC. In this review, we extracted data from 1,752 articles on NDDS-based treatment of BC published between 2012 and 2022 from the Web of Science Core Collection (WOSCC) database. VOSviewer, CiteSpace, and some online platforms were used for bibliometric analysis and visualization. Publication trends were initially observed: in terms of geographical distribution, China and the United States had the most papers on this subject. The highest contributing institution was Sichuan University. In terms of authorship and co-cited authorship, the most prolific author was Yu Zhang. Furthermore, Qiang Zhang and co-workers have made tremendous achievements in the field of NDDS-based BC treatment. The article titled "Nanomedicine in cancer therapy: challenges, opportunities, and clinical applications" had the most citations. The Journal of Controlled Release was one of the most active publishers in the field. "Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries" was the most cited reference. We also analysed "hot" and cutting-edge research for NDDSs in BC treatment. There were nine topic clusters: "tumour microenvironment," "nanoparticles (drug delivery)," "breast cancer/triple-negative breast cancer," "combination therapy," "drug release (pathway)," "multidrug resistance," "recent advance," "targeted drug delivery", and "cancer nanomedicine." We also reviewed the core themes of research. In summary, this article reviewed the application of NDDSs in the treatment of BC.

Magnetic nanoparticle swarm with upstream motility and peritumor blood vessel crossing ability

Micro-nano-robots show great potential and value for applications in targeted drug delivery; however, very few current studies have enabled micro-nano-robots to move against blood flow, and in addition, how micro-nano-robots can penetrate endothelial cells and enter tissues via vascular permeation remains unclear. Inspired by the bionics of dynamic aggregation in wild herring schools and transvascular permeation of leukocytes, we propose a novel drug delivery strategy where thousands of magnetic nanoparticles (MNPs) can be assembled into swarms under the guidance of a specially designed electromagnetic field. The vortex-like swarms of magnetic nanoparticles exhibit excellent stability, allowing them to withstand the impact of high-speed flow and move upstream along the vessel wall, stopping at the target location. When the vortex-like swarms encounter a tumor periphery without a continuous vessel wall, their rheological properties actively adhere them to the edges of the vascular endothelial gap, using their deformability to crawl through narrow intercellular gaps, enabling large-scale targeted drug delivery. This cluster of miniature nanorobots can be reshaped and reconfigured to perform a variety of tasks according to the environmental demands of the circulatory system, providing new solutions for a variety of biomedical field applications.

Awakening Allies for Breaking Microenvironment Barriers: NIR-II Guided Orthogonal Activation of Tumor-Infiltrating Mast Cells for Efficient Nano-Drug Delivery

Mast cells (MCs), powerful immune cells that heavily infiltrate cancer cells, play a crucial role in tumor formation. Activated MCs can release histamine and a family of proteases through degranulation effects, concurrently achieving endothelial junction weakening and stromal degradation of the tumor microenvironment, thereby clearing the obstacles for nano-drug infiltration. To achieve precise activation of tumor-infiltrating MCs, orthogonally excited rare earth nanoparticles (ORENP), with two channels, are introduced for the controllable stimulating drugs release wrapped in "photocut tape". The ORENP can emit near-infrared II (NIR-II) for image tracing for tumor localization in Channel 1 (808/NIR-II) and allows energy upconversion to emit ultraviolet (UV) light for releasing drugs for MCs stimulation in Channel 2 (980/UV). Finally, the combined use of chemical and cellular tools enables clinical nano-drugs to achieve a significant increase in tumor infiltration, thereby enhancing the efficacy of nano-chemotherapy.

Nanomedicine in cancer therapy

Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines.

Effective Attenuation of Arteriosclerosis Following Lymphatic-Targeted Delivery of Hyaluronic Acid-Decorated Rapamycin Liposomes

Background

The activation of lymphatic vessel function is the crux to resolving atherosclerosis (AS), a chronic inflammatory disease. Rapamycin (RAPA) recently has attracted considerable attention as a potent drug to induce atherosclerotic plaque attenuation. The objective of this work was to develop a ligand-decorated, RAPA-loaded liposome for lymphatic-targeted delivery of drugs to improve abnormal lymphatic structure and function, resulting in highly effective regression of atherosclerotic plaques.

Methods

Hyaluronic acid-decorated, RAPA-loaded liposomes (HA-RL) were fabricated by emulsion-solvent evaporation. The average size, zeta potential, entrapment efficiency were characterized, and the stability and drug release in vitro were investigated. Furthermore, the in vitro and in vivo lymphatic targeting ability were evaluated on lymphatic endothelial cells and LDLR-/- mice, and the efficiency of this nano-system in inducing the attenuation of atherosclerotic plaques was confirmed.

Results

HA-RL had a size of 100 nm, over 90% drug encapsulation efficiency, the storage stability was distinguished, demonstrating a slow release from the lipid nano-carriers. The mean retention time (MRT) and elimination half-life (t1/2β) achieved from HA-RL were 100.27±73.08 h and 70.74±50.80 h, respectively. HA-RL acquired the most prominent efficacy of lymphatic-targeted delivery and atherosclerotic plaques attenuation, implying the successful implementation of this novel drug delivery system in vivo.

Conclusion

HA-RL exhibited the most appreciable lymphatic targeting ability and best atherosclerotic plaques attenuation efficiency, opening a new paradigm and promising perspective for the treatment of arteriosclerosis.

Overcoming tumor microenvironment obstacles: Current approaches for boosting nanodrug delivery

In order to achieve targeted delivery of anticancer drugs, efficacy improvement, and side effect reduction, various types of nanoparticles are employed. However, their therapeutic effects are not ideal. This phenomenon is caused by tumor microenvironment abnormalities such as abnormal blood vessels, elevated interstitial fluid pressure, and dense extracellular matrix that affect nanoparticle penetration into the tumor's interstitium. Furthermore, nanoparticle properties including size, charge, and shape affect nanoparticle transport into tumors. This review comprehensively goes over the factors hindering nanoparticle penetration into tumors and describes methods for improving nanoparticle distribution by remodeling the tumor microenvironment and optimizing nanoparticle physicochemical properties. Finally, a critical analysis of future development of nanodrug delivery in oncology is further discussed. STATEMENT OF SIGNIFICANCE: This article reviews the factors that hinder the distribution of nanoparticles in tumors, and describes existing methods and approaches for improving the tumor accumulation from the aspects of remodeling the tumor microenvironment and optimizing the properties of nanoparticles. The description of the existing methods and approaches is followed by highlighting their advantages and disadvantages and put forward possible directions for the future researches. At last, the challenges of improving tumor accumulation in nanomedicines design were also discussed. This review will be of great interest to the broad readers who are committed to delivering nanomedicine for cancer treatment.

Nanoceria as Safe Contrast Agents for X-ray CT Imaging

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations.

Engineering tumoral vascular leakiness with gold nanoparticles

Delivering cancer therapeutics to tumors necessitates their escape from the surrounding blood vessels. Tumor vasculatures are not always sufficiently leaky. Herein, we engineer therapeutically competent leakage of therapeutics from tumor vasculature with gold nanoparticles capable of inducing endothelial leakiness (NanoEL). These NanoEL gold nanoparticles activated the loss of endothelial adherens junctions without any perceivable toxicity to the endothelial cells. Microscopically, through real time live animal intravital imaging, we show that NanoEL particles induced leakiness in the tumor vessels walls and improved infiltration into the interstitial space within the tumor. In both primary tumor and secondary micrometastases animal models, we show that pretreatment of tumor vasculature with NanoEL particles before therapeutics administration could completely regress the cancer. Engineering tumoral vasculature leakiness represents a new paradigm in our approach towards increasing tumoral accessibility of anti-cancer therapeutics instead of further increasing their anti-cancer lethality.

Biomimetic Epigallocatechin Gallate-Cerium Assemblies for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that is so far incurable with long-term health risks. The high doses and frequent administration for the available RA drug always lead to adverse side effects. Aiming at the obstacles to achieving effective RA treatment, we prepared macrophage cell membrane-camouflaged nanoparticles (M-EC), which were assembled from epigallocatechin gallate (EGCG) and cerium(IV) ions. Due to its geometrical similarity to the active metal sites of a natural antioxidant enzyme, the EC possessed a high scavenge efficiency to various types of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The macrophage cell membrane assisted M-EC in escaping from the immune system, being uptaken by inflammatory cells, and specifically binding IL-1β. After tail vein injection to the collagen-induced arthritis (CIA) mouse model, the M-EC accumulated at inflamed joints and effectively repaired the bone erosion and cartilage damage of rheumatoid arthritis by relieving synovial inflammation and cartilage erosion. It is expected that the M-EC can not only pave a new way for designing metal-phenolic networks with better biological activity but also provide a more biocompatible therapeutic strategy for effective treatment of RA.

Nanoparticle-Mediated Radiotherapy Remodels the Tumor Microenvironment to Enhance Antitumor Efficacy

Radiotherapy (RT) uses ionizing radiation to eradicate localized tumors and, in rare cases, control tumors outside of the irradiated fields via stimulating an antitumor immune response (abscopal effect). However, the therapeutic effect of RT is often limited by inherent physiological barriers of the tumor microenvironment (TME), such as hypoxia, abnormal vasculature, dense extracellular matrix (ECM), and an immunosuppressive TME. Thus, it is critical to develop new RT strategies that can remodel the TME to overcome radio-resistance and immune suppression. In the past decade, high-Z-element nanoparticles have been developed to increase radiotherapeutic indices of localized tumors by reducing X-ray doses and side effects to normal tissues and enhance abscopal effects by activating the TME to elicit systemic antitumor immunity. In this review, the principles of RT and radiosensitization, the mechanisms of radio-resistance and immune suppression, and the use of various nanoparticles to sensitize RT and remodel TMEs for enhanced antitumor efficacy are discussed. The challenges in clinical translation of multifunctional TME-remodeling nanoradiosensitizers are also highlighted.

Neutrophil-Membrane-Coated Biomineralized Metal-Organic Framework Nanoparticles for Atherosclerosis Treatment by Targeting Gene Silencing

Antisense oligonucleotides (ASOs) are promising tools for gene silencing and have been exploited as therapeutics for human disease. However, delivery of therapeutic ASOs to diseased tissues or cells and subsequent escape from the endosomes and release of ASO in the cytosol remain a challenge. Here, we reported a neutrophil-membrane-coated zeolitic imidazolate framework-8 (ZIF-8) nanodelivery platform (AM@ZIF@NM) for the targeted transportation of ASOs against microRNA-155 (anti-miRNA-155) to the endothelial cells in atherosclerotic lesions. Neutrophil membrane could improve plaque endothelial cells targeting through the interaction between neutrophil membrane protein CD18 and endothelial cell membrane protein intercellular adhesion molecule-1 (ICAM-1). The ZIF-8 "core" provided high loading capacity and efficient endolysosomal escaping ability. Delivery of anti-miR-155 effectively downregulated miR-155 expression and also saved the expression of its target gene BCL6. Moreover, RELA expression and the expression of its downstream target genes CCL2 and ICAM-1 were correspondingly reduced. Consequently, this anti-miR-155 nanotherapy can inhibit the inflammation of atherosclerotic lesions and alleviate atherosclerosis. Our study shows that the designed biomimetic nanodelivery system has great application prospects in the treatment of other chronic diseases.

Mechanistic Understanding of Protein Corona Formation around Nanoparticles: Old Puzzles and New Insights

Although a wide variety of nanoparticles (NPs) have been engineered for use as disease markers or drug delivery agents, the number of nanomedicines in clinical use has hitherto remained small. A key obstacle in nanomedicine development is the lack of a deep mechanistic understanding of NP interactions in the bio-environment. Here, the focus is on the biomolecular adsorption layer (protein corona), which quickly enshrouds a pristine NP exposed to a biofluid and modifies the way the NP interacts with the bio-environment. After a brief introduction of NPs for nanomedicine, proteins, and their mutual interactions, research aimed at addressing fundamental properties of the protein corona, specifically its mono-/multilayer structure, reversibility and irreversibility, time dependence, as well as its role in NP agglomeration, is critically reviewed. It becomes quite evident that the knowledge of the protein corona is still fragmented, and conflicting results on fundamental issues call for further mechanistic studies. The article concludes with a discussion of future research directions that should be taken to advance the understanding of the protein corona around NPs. This knowledge will provide NP developers with the predictive power to account for these interactions in the design of efficacious nanomedicines.

Theranostic applications of selenium nanomedicines against lung cancer

The incidence and mortality rates of lung cancer are among the highest in the world. Traditional treatment methods include surgery, chemotherapy, and radiotherapy. Although rapid progress has been achieved in the past decade, treatment limitations remain. It is therefore imperative to identify safer and more effective therapeutic methods, and research is currently being conducted to identify more efficient and less harmful drugs. In recent years, the discovery of antitumor drugs based on the essential trace element selenium (Se) has provided good prospects for lung cancer treatments. In particular, compared to inorganic Se (Inorg-Se) and organic Se (Org-Se), Se nanomedicine (Se nanoparticles; SeNPs) shows much higher bioavailability and antioxidant activity and lower toxicity. SeNPs can also be used as a drug delivery carrier to better regulate protein and DNA biosynthesis and protein kinase C activity, thus playing a role in inhibiting cancer cell proliferation. SeNPs can also effectively activate antigen-presenting cells to stimulate cell immunity, exert regulatory effects on innate and regulatory immunity, and enhance lung cancer immunotherapy. This review summarizes the application of Se-based species and materials in lung cancer diagnosis, including fluorescence, MR, CT, photoacoustic imaging and other diagnostic methods, as well as treatments, including direct killing, radiosensitization, chemotherapeutic sensitization, photothermodynamics, and enhanced immunotherapy. In addition, the application prospects and challenges of Se-based drugs in lung cancer are examined, as well as their forecasted future clinical applications and sustainable development.

Revealing the In Situ Behavior of Aggregation-Induced Emission Nanoparticles and Their Biometabolic Effects via Mass Spectrometry Imaging

Simultaneous imaging of exogenous nanomaterials and endogenous metabolites in situ remains challenging and is beneficial for a systemic understanding of the biological behavior of nanomaterials at the molecular level. Here, combined with label-free mass spectrometry imaging, visualization and quantification of the aggregation-induced emission nanoparticles (NPs) in tissue were realized as well as related endogenous spatial metabolic changes simultaneously. Our approach enables us to identify the heterogeneous deposition and clearance behavior of nanoparticles in organs. The accumulation of nanoparticles in normal tissues results in distinct endogenous metabolic changes such as oxidative stress as indicated by glutathione depletion. The low passive delivery efficiency of nanoparticles to tumor foci suggested that the enrichment of NPs in tumors did not benefit from the abundant tumor vessels. Moreover, spatial-selective metabolic changes upon NPs mediated photodynamic therapy was identified, which enables understanding of the NPs induced apoptosis in the process of cancer therapy. This strategy allows us to simultaneously detect exogenous nanomaterials and endogenous metabolites in situ, hence to decipher spatial selective metabolic changes in drug delivery and cancer therapy processes.

Negatively charged Cu1.33S nanochains: endocytic pathway, photothermal therapy and toxic effect in vivo

Negatively charged nanomaterials have good biocompatibility and low cytotoxicity, but the efficiency of their entry into cells is relatively low. Thus, striking a balance between cell transport efficiency and cytotoxicity is a challenging problem in the field of nanomedicine. In this work, negatively charged Cu_1.33S nanochains have shown a higher cellular uptake level in 4T1 cells than Cu_1.33S nanoparticles with a similar diameter and surface charge. Inhibition experiments indicate that the cellular uptake of the nanochains depends principally on the lipid-raft protein (i.e. caveolin-1) mediated pathway, although the role of clathrin cannot be ruled out. Caveolin-1 can provide short-range attraction at the membrane interface. Furthermore, by using biochemical analysis, blood routine examination and histological evaluation on healthy Sprague Dawley rats, it is found that the Cu_1.33S nanochains have no obvious toxic effect. The Cu_1.33S nanochains have an effective photothermal therapy effect of tumor ablation in vivo under low injection dosage and laser intensity. As for the best performing group (20 μg + 1 W cm^-2), the temperature of the tumor site rapidly increases within the initial 3 min and rises to a plateau of 79 °C (ΔT = 46 °C) at 5 min. These results reveal the feasibility of the Cu_1.33S nanochains as a photothermal agent.

An "IgG-hitchhiking" approach for rapid tumor accumulation and clearance of photosensitizers

Photodynamic therapy (PDT) has been widely used for the local treatment of a variety of cancer. To improve the therapeutic effect, delicate nanoparticles loading photosensitizers (PSs) have been designed to improve the accumulation of PSs in tumor. Different from the anti-cancer drugs for chemotherapy or immunotherapy, the delivery of PSs requires rapid tumor accumulation followed by quick elimination to reduce the potential risk of phototoxicity. However, owing to the nature of prolonged blood circulation of the nanoparticles, the conventional nanoparticulate delivery systems may decelerate the clearance of PSs. Here, we present a tumor-targeted delivery approach termed "IgG-hitchhiking" strategy through a self-assembled PSs nanostructure, according to the intrinsic binding between the photosensitizer pheophorbide A (PhA) and immunoglobulin (IgG). We utilize the intravital fluorescence microscopic imaging to uncover that the nanostructures (IgG:PhA NPs) increase the extravasation of PhA into tumor within the first hour post intravenous injection compared with free PhA, correlating with an improved efficacy of PDT. After ∼1 h post-injection, a quick decrease in the PhA amount in the tumor is observed, while the tumor IgG level is continuously increasing. The disparity of the tumor distribution between PhA and IgG allows the quick elimination of the PSs for minimized skin phototoxicity. Our results provide a direct evidence of the enhanced accumulation and elimination of the PSs in the tumor microenvironment through the "IgG-hitchhiking" approach. This strategy presents a promising tumor-targeted delivery approach for the PSs in lieu of the existing strategy for enhanced PDT with minimal toxicity in clinic.

Biomimetic cell membrane-coated poly(lactic-co-glycolic acid) nanoparticles for biomedical applications

Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) are commonly used for drug delivery because of their favored biocompatibility and suitability for sustained and controlled drug release. To prolong NP circulation time, enable target-specific drug delivery and overcome physiological barriers, NPs camouflaged in cell membranes have been developed and evaluated to improve drug delivery. Here, we discuss recent advances in cell membrane-coated PLGA NPs, their preparation methods, and their application to cancer therapy, management of inflammation, treatment of cardiovascular disease and control of infection. We address the current challenges and highlight future research directions needed for effective use of cell membrane-camouflaged NPs.

Biomimetic Nanobomb for Synergistic Therapy with Inhibition of Cancer Stem Cells

Cancer stem cells (CSCs), a type of cell with self-renewal, unlimited proliferation, and insensitivity to common physical and chemical factors, are the key to cancer metastasis, recurrence, and chemo-resistance. Available CSCs inhibition strategies are mainly based on small molecule drugs, yet are limited by their off-target toxicity. The link between CSCs and non-CSCs interconversion is difficult to sever. In this work, a nanotherapeutic strategy based on MnO_x -loaded polydopamine (MnO_x /PDA) nanobombs with chemodynamic, photodynamic, photothermal and biodegradation properties to inhibit CSCs and non-CSCs concurrently is reported. The MnO_x /PDA nanobombs can directly disrupt the microenvironment and tumorigenic capacity of CSCs by generating hyperthermia, oxidative stress and alleviating hypoxia. The markers of CSCs are subsequently downregulated, leading to the clearance of CSCs. Meanwhile, the synergistic therapy mediated by MnO_x /PDA nanobombs can directly ablate the bulk tumor cells, thus cutting off the supply of CSCs transformation. For tumor targeting, MnO_x /PDA is coated with macrophage membrane. The final tumor inhibition rate of the synergistic therapy is 70.8% in colorectal cancer (CRC) model. Taken together, the present work may open up the exploration of nanomaterial-based synergistic therapy for the simultaneous elimination of therapeutically resistant CSCs and non-CSCs.

Radiation-assisted strategies provide new perspectives to improve the nanoparticle delivery to tumor

Nanoparticles (NPs), with advantages in tumor targeting, have been extensively developed for anticancer treatment. However, the delivery efficacy of NPs tends to be heterogeneous in clinical research. Surprisingly, a traditional cancer treatment, radiotherapy (radiation), has been observed with the potential to improve the delivery of NPs by influencing the features of the tumor microenvironment, which provides new perspectives to overcome the barriers in the NPs delivery. Since the effect of radiation can also be enhanced by versatile NPs, these findings of radiation-assisted NPs delivery suggest innovative strategies combining radiotherapy with nanotherapeutics. This review summarizes the research on the delivery and therapeutic efficacy of NPs that are improved by radiation, focusing on relative mechanisms and existing challenges and opportunities.

Multifunctional Protein Hybrid Nanoplatform for Synergetic Photodynamic-Chemotherapy of Malignant Carcinoma by Homologous Targeting Combined with Oxygen Transport

Photodynamic therapy (PDT) under hypoxic conditions and drug resistance in chemotherapy are perplexing problems in anti-tumor treatment. In addition, central nervous system neoplasm-targeted nanoplatforms are urgently required. To address these issues, a new multi-functional protein hybrid nanoplatform is designed, consisting of transferrin (TFR) as the multicategory solid tumor recognizer and hemoglobin for oxygen supply (ODP-TH). This protein hybrid framework encapsulates the photosensitizer protoporphyrin IX (PpIX) and chemotherapeutic agent doxorubicin (Dox), which are attached by a glutathione-responsive disulfide bond. Mechanistically, ODP-TH crosses the blood-brain barrier (BBB) and specifically aggregated in hypoxic tumors via protein homology recognition. Oxygen and encapsulated drugs ultimately promote a therapeutic effect by down-regulating the abundance of multidrug resistance gene 1 (MDR1) and hypoxia-inducible factor-1-α (HIF-1α). The results reveal that ODP-TH achieves oxygen transport and protein homology recognition in the hypoxic tumor occupation. Indeed, compared with traditional photodynamic chemotherapy, ODP-TH achieves a more efficient tumor-inhibiting effect. This study not only overcomes the hypoxia-related inhibition in combination therapy by targeted oxygen transport but also achieves an effective treatment of multiple tumors, such as breast cancer and glioma, providing a new concept for the construction of a promising multi-functional targeted and intensive anti-tumor nanoplatform.

Impact of tumoral structure and bacterial species on growth and biodistribution of live bacterial therapeutics in xenografted tumours

Live bacterial therapeutics is gaining attention, especially for cancer therapy, because anaerobic bacteria selectively grow inside the solid tumours. However, the effect of tumour structure and bacterial characteristics on the pharmacokinetics of tumours is unclear; therefore, we aimed to elucidate the effects of tumour structure and types of bacteria on tumoral bacterial growth. Using six mouse xenograft models, including stroma-rich tumours similar to clinical tumours, and two models of live bacterial therapeutics, Salmonella typhimurium VNP20009 and Escherichia coli DH5α, we investigated bacterial growth and distribution in tumours after intravenous administration. Rapid growth of E. coli was observed in HCT116 and other tumours with few collagens, blood vessels not covered by mural cells, and a cancer cell area proliferated disorderly, whereas tumours with contrasting features, such as BxPC-3, showed lower bacterial growth and a limited intratumor distribution. Alternatively, Salmonella typhimurium VNP20009, when successfully proliferated (the probability was approximately 50%), grew to 10⁸ colony forming units/g tissue even in BxPC-3 tumours, and its intratumor distribution was extensive. This study suggests that the development of new methods to modify tumour structure will be essential for the development of anti-tumour clinical therapies based on live bacterial therapeutics.

Therapeutic Strategies to Overcome Fibrotic Barriers to Nanomedicine in the Pancreatic Tumor Microenvironment

Pancreatic cancer is notorious for its dismal prognosis. The enhanced permeability and retention (EPR) effect theory posits that nanomedicines (therapeutics in the size range of approximately 10-200 nm) selectively accumulate in tumors. Nanomedicine has thus been suggested to be the "magic bullet"-both effective and safe-to treat pancreatic cancer. However, the densely fibrotic tumor microenvironment of pancreatic cancer impedes nanomedicine delivery. The EPR effect is thus insufficient to achieve a significant therapeutic effect. Intratumoral fibrosis is chiefly driven by aberrantly activated fibroblasts and the extracellular matrix (ECM) components secreted. Fibroblast and ECM abnormalities offer various potential targets for therapeutic intervention. In this review, we detail the diverse strategies being tested to overcome the fibrotic barriers to nanomedicine in pancreatic cancer. Strategies that target the fibrotic tissue/process are discussed first, which are followed by strategies to optimize nanomedicine design. We provide an overview of how a deeper understanding, increasingly at single-cell resolution, of fibroblast biology is revealing the complex role of the fibrotic stroma in pancreatic cancer pathogenesis and consider the therapeutic implications. Finally, we discuss critical gaps in our understanding and how we might better formulate strategies to successfully overcome the fibrotic barriers in pancreatic cancer.

Organism-Generated Biological Vesicles In Situ: An Emerging Drug Delivery Strategy

Biological vesicles, containing genetic materials and proteins of the original cells, are usually used for local or systemic communications among cells. Currently, studies on biological vesicles as therapeutic strategies or drug delivery carriers mainly focus on exogenously generated biological vesicles. However, the limitations of yield and purity caused by the complex purification process still hinder their clinical transformation. Recently, it has been reported that living organisms, including cells and bacteria, can produce functional/therapeutic biological vesicles within body automatically. Therefore, using organisms to produce endogenous biological vesicles in body as drug/bio-information delivery carriers has become a potential therapeutic strategy. In this review, the current development status and application prospects of in situ organism-produced biological vesicles are introduced. The advantages and effects of this endogenous biological vesicles-based strategy in drug delivery and disease treatments are analyzed. According to the type of endogenous biological vesicles, they are divided into four categories: exosomes, platelet-derived microparticles, apoptotic bodies, and bacteria-released outer membrane vesicles. And finally, the shortcomings of current research and future development are analyzed. This review is believed to open up the application of endogenous biological vesicles in the field of biomedicine and shed light on current research.

Carbonaceous Nanomaterials for Phototherapy of Cancer

Carbonaceous nanomaterials (CNMs) have drawn tremendous biomedical research interest because of their unique structural features. Recently, CNMs, namely carbon dots, fullerenes, graphene, etc, have been successful in establishing them as considerable nanotherapeutics for phototherapy applications due to their electrical, thermal, and surface properties. This review aims to crosstalk the current understanding of CNMs as multimodal compounds in photothermal and photodynamic therapies as an integrated approach to treating cancer. It also expounds on phototherapy's biomechanics and illustrates its relation to cancer biomodulation. Critical considerations related to the structural properties, fabrication approaches, surface functionalization strategies, and biosafety profiles of CNMs have been explained. This article provides an overview of the most recent developments in the study of CNMs used in phototherapy, emphasizing their usage as nanocarriers. To conquer the current challenges of CNMs, we can raise the standard of cancer therapy for patients. The review will be of interest to the researchers working in the area of photothermal and photodynamic therapies and aiming to explore CNMs and their conjugates in cancer therapy.

Supermagnetic Human Serum Albumin (HSA) Nanoparticles and PLGA-Based Doxorubicin Nanoformulation: A Duet for Selective Nanotherapy

Predicting the ability of nanoparticles (NP) to access the tumor is key to the success of chemotherapy using nanotherapeutics. In the present study, the ability of the dual NP-based theranostic system to accumulate in the tumor was evaluated in vivo using intravital microscopy (IVM) and MRI. The system consisted of model therapeutic doxorubicin-loaded poly(lactide-co-glycolide) NP (Dox-PLGA NP) and novel hybrid Ce^3/4+-doped maghemite NP encapsulated within the HSA matrix (hMNP) as a supermagnetic MRI contrasting agent. Both NP types had similar sizes of ~100 nm and negative surface potentials. The level of the hMNP and PLGA NP co-distribution in the same regions of interest (ROI, ~2500 µm²) was assessed by IVM in mice bearing the 4T1-mScarlet murine mammary carcinoma at different intervals between the NP injections. In all cases, both NP types penetrated into the same tumoral/peritumoral regions by neutrophil-assisted extravasation through vascular micro- and macroleakages. The maximum tumor contrasting in MRI scans was obtained 5 h after hMNP injection/1 h after PLGA NP injection; the co-distribution level at this time reached 78%. Together with high contrasting properties of the hMNP, these data indicate that the hMNP and PLGA NPs are suitable theranostic companions. Thus, analysis of the co-distribution level appears to be a useful tool for evaluation of the dual nanoparticle theranostics, whereas assessment of the leakage areas helps to reveal the tumors potentially responsive to nanotherapeutics.

Chemical Approaches to Synthetic Drug Delivery Systems for Systemic Applications

Poor water solubility and low bioavailability of active pharmaceutical ingredients (APIs) are major causes of friction in the pharmaceutical industry and represent a formidable hurdle for pharmaceutical drug development. Drug delivery remains the major challenge for the application of new small-molecule drugs as well as biopharmaceuticals. The three challenges for synthetic delivery systems are: (i) controlling drug distribution and clearance in the blood; (ii) solubilizing poorly water-soluble agents, and (iii) selectively targeting specific tissues. Although several polymer-based systems have addressed the first two demands and have been translated into clinical practice, no targeted synthetic drug delivery system has reached the market. This Review is designed to provide a background on the challenges and requirements for the design and translation of new polymer-based delivery systems. This report will focus on chemical approaches to drug delivery for systemic applications.

Cell-Derived Vesicles for Nanoparticles' Coating: Biomimetic Approaches for Enhanced Blood Circulation and Cancer Therapy

Cancer nanomedicines are designed to encapsulate different therapeutic agents, prevent their premature release, and deliver them specifically to cancer cells, due to their ability to preferentially accumulate in tumor tissue. However, after intravenous administration, nanoparticles immediately interact with biological components that facilitate their recognition by the immune system, being rapidly removed from circulation. Reports show that less than 1% of the administered nanoparticles effectively reach the tumor site. This suboptimal pharmacokinetic profile is pointed out as one of the main factors for the nanoparticles' suboptimal therapeutic effectiveness and poor translation to the clinic. Therefore, an extended blood circulation time may be crucial to increase the nanoparticles' chances of being accumulated in the tumor and promote a site-specific delivery of therapeutic agents. For that purpose, the understanding of the forces that govern the nanoparticles' interaction with biological components and the impact of the physicochemical properties on the in vivo fate will allow the development of novel and more effective nanomedicines. Therefore, in this review, the nano-bio interactions are summarized. Moreover, the application of cell-derived vesicles for extending the blood circulation time and tumor accumulation is reviewed, focusing on the advantages and shortcomings of each cell source.

The tumor EPR effect for cancer drug delivery: Current status, limitations, and alternatives

Over the past three decades, the enhanced permeability and retention (EPR) effect has been considered the basis of tumor-targeted drug delivery. Various cancer nanomedicines, including macromolecular drugs, have been designed to utilize this mechanism for preferential extravasation and accumulation in solid tumors. However, such nanomedicines have not yet achieved convincing therapeutic benefits in clinics. Increasing evidence suggests that the EPR effect is over-represented in human tumors, especially in metastatic tumors. This review covers the evolution of the concept, the heterogeneity and limitation of the EPR effect in clinical realities, and prospects for alternative strategies independent of the EPR effect.