A pH-Responsive Cluster Metal-Organic Framework Nanoparticle for Enhanced Tumor Accumulation and Antitumor Effect

Traditional Chinese Medicine Integrated Multifunctional Responsive Core-Shell Microneedles for Dermatosis Treatment

Microneedles have demonstrated value in targeted treatment of dermatosis. Current investigation aims to enhance the functions and optimize substance delivery to improve therapeutic effects. Here, we present innovative shell-core microneedles with light-pH dual responsiveness for spatiotemporal sequential release of multiple Chinese herb drugs to treat scleroderma. By using a stepwise template-assisted method, we effectively prepare a hydrogel-based core layer containing polydopamine-MXene (P-MXene) loaded with triptolide (TP), and a shell layer composed of polyvinyl alcohol (PVA) encapsulating paeoniflorin (Pae). P-MXene can adsorb the sparingly soluble TP to ensure its encapsulation efficiency and contribute to the synergistic photothermal effect benefitting from its excellent photothermal conversion ability. Besides, PVA can rapidly dissolve upon microneedle piercing into the skin and quickly release the anti-inflammatory and detoxifying Pae, establishing a favorable low-acid subcutaneous environment. In response to pH changes and near-infrared effects, TP is sustainably released from P-MXene and delivered through the swollen pores of the hydrogel. On the basis of these characteristics, we demonstrate that these microneedles could effectively reduce profibrotic key cytokines interleukin-1β and transforming growth factor-β, thereby reducing collagen deposition and decreasing epidermal thickness, ameliorating skin fibrosis and capillary lesion in scleroderma mouse models. These findings highlight the important clinical potential of these microneedles in the treatment of skin diseases.

Metal organic framework-based variable-size nanoparticles for tumor microenvironment-responsive drug delivery

Nanoparticles (NPs) have been designed for the treatment of tumors increasingly. However, the drawbacks of single-size NPs are still worth noting, as their circulation and metabolism in the blood are negatively correlated with their accumulation at the tumor site. If the size of single-size NPs is too small, it will be quickly cleared in the blood circulation, while, the size is too large, the distribution of NPs in the tumor site will be reduced, and the widespread distribution of NPs throughout the body will cause systemic toxicity. Therefore, a class of variable-size NPs with metal organic frameworks (MOFs) as the main carrier, and size conversion in compliance with the characteristics of the tumor microenvironment (TME), was designed. MOF-based variable-size NPs can simultaneously extend the time of blood circulation and metabolism, then enhance the targeting ability of the tumor site. In this review, MOF NPs are categorized and exemplified from a new perspective of NP size variation; the advantages, mechanisms, and significance of MOF-based variable-size NPs were summarized, and the potential and challenges in delivering anti-tumor drugs and multimodal combination therapy were discussed.

Biomimetic Exosome-Sheathed Magnetic Mesoporous Anchor with Modification of Glucose Oxidase for Synergistic Targeting and Starving Tumor Cells

Efficient protection and precise delivery of biomolecules are of critical importance in the intervention and therapy of various diseases. Although diverse specific marker-functionalized drug carriers have been developed rapidly, current approaches still encounter substantial challenges, including strong immunogenicity, limited target availability, and potential side effects. Herein, we developed a biomimetic exosome-sheathed magnetic mesoporous anchor modified with glucose oxidase (MNPs@mSiO2-GOx@EM) to address these challenges and achieve synergistic targeting and starving of tumor cells. The MNPs@mSiO2-GOx@EM anchor integrated the unique characteristics of different components. An external decoration of exosome membrane (EM) with high biocompatibility contributed to increased phagocytosis prevention, prolonged circulation, and enhanced recognition and cellular uptake of loaded particles. An internal coated magnetic mesoporous core with rapid responsiveness by the magnetic field guidance and large surface area facilitated the enrichment of nanoparticles at the specific site and provided enough space for modification of glucose oxidase (GOx). The inclusion of GOx in the middle layer accelerated the energy-depletion process within cells, ultimately leading to the starvation and death of target cells with minimal side effects. With these merits, in vitro study manifested that our nanoplatform not only demonstrated an excellent targeting capability of 94.37% ± 1.3% toward homotypic cells but also revealed a remarkably high catalytical ability and cytotoxicity on tumor cells. Assisted by the magnetic guidance, the utilization of our anchor obviously inhibits the tumor growth in vivo. Together, our study is promising to serve as a versatile method for the highly efficient delivery of various target biomolecules to intended locations due to the fungibility of exosome membranes and provide a potential route for the recognition and starvation of tumor cells.

Metabolism-Regulating Nanozyme System for Advanced Nanocatalytic Cancer Therapy

Nanocatalytic therapy, an emerging approach in cancer treatment, utilizes nanomaterials to initiate enzyme-mimetic catalytic reactions within tumors, inducing tumor-suppressive effects. However, the targeted and selective catalysis within tumor cells is challenging yet critical for minimizing the adverse effects. The distinctive reliance of tumor cells on glycolysis generates abundant lactate, influencing the tumor's pH, which can be manipulated to selectively activate nanozymatic catalysis. Herein, small interfering ribonucleic acid (siRNA) targeting lactate transporter-mediated efflux is encapsulated within the iron-based metal-organic framework (FeMOF) and specifically delivered to tumor cells through cell membrane coating. This approach traps lactate within the cell, swiftly acidifying the tumor cytoplasm and creating an environment for boosting the catalysis of the FeMOF nanozyme. The nanozyme generates hydroxyl radical (·OH) in the reversed acidic environment, using endogenous hydrogen peroxide (H2O2) produced by mitochondria as a substrate. The induced cytoplasmic acidification disrupts calcium homeostasis, leading to mitochondrial calcium overload, resulting in mitochondrial dysfunction and subsequent tumor cell death. Additionally, the tumor microenvironment is also remodeled, inhibiting migration and invasion, thus preventing metastasis. This groundbreaking strategy combines metabolic regulation with nanozyme catalysis in a toxic drug-free approach for tumor treatment, holding promise for future clinical applications.

Fe3O4-Incorporated Metal-Organic Framework for Chemo/Ferroptosis Synergistic Anti-Tumor via the Enhanced Chemodynamic Therapy

Metal-organic framework (MOF)-based drug delivery nanomaterials for cancer therapy have attracted increasing attention in recent years. Here, an enhanced chemodynamic anti-tumor therapy strategy by promoting the Fenton reaction by using core-shell zeolitic imidazolate framework-8 (ZIF-8)@Fe3O4 as a therapeutic platform is proposed. Carboxymethyl cellulose (CMC) is used as a stabilizer of Fe3O4, which is then decorated on the surface of ZIF-8 via the electrostatic interaction and serves as an efficient Fenton reaction trigger. Meanwhile, the pH-responsive ZIF-8 scaffold acts as a container to encapsulate the chemotherapeutic drug doxorubicin (DOX). The obtained DOX-ZIF-8@Fe3O4/CMC (DZFC) nanoparticles concomitantly accelerate DOX release and generate more hydroxyl radicals by targeting the lysosomes in cancer cells. In vitro and in vivo studies verify that the DZFC nanoparticles trigger glutathione peroxidase 4 (GPX4)-dependent ferroptosis via the activation of the c-Jun N-terminal kinases (JNK) signaling pathway, following to achieve the chemo/ferroptosis synergistic anti-tumor efficacy. No marked toxic effects are detected during DZFC treatment in a tumor-bearing mouse model. This composite nanoparticle remarkably suppresses the tumor growth with minimized systemic toxicity, opening new horizons for the next generation of theragnostic nanomedicines.

Elucidation of Spatial Cooperativity in Chemo-Immunotherapy by a Sequential Dual-pH-Responsive Drug Delivery System

Combining immune checkpoint blockade with chemotherapy through nanotechnology is promising in terms of safety and efficacy. However, the distinct subcellular distribution of each ingredient's action site makes it challenging to acquire an optimal synergism. Herein, a dual-pH responsive hybrid polymeric micelle system, HNP(αPDL16.9, Dox5.3), is constructed as a proof-of-concept for the spatial cooperativity in chemo-immunotherapy. HNP retains the inherent pH-transition of each polymer, with stepwise disassembly under discrete pH thresholds. Within weakly acidic extracellular tumor environment, αPDL1 is first released to block the checkpoint on cell membranes. The remaining intact Doxorubicin-loaded micelle NP(Dox)5.3 displays significant tropism toward tumor cells and releases Dox upon lysosomal pH for efficient tumor immunogenic cell death without immune toxicity. This sequential-released pattern boosts DC activation and primes CD8+ T cells, leading to enhanced therapeutic performance than single agent or an inverse-ordered combination in multiple murine tumor models. Using HNP, the indispensable role of conventional type 1 DC (cDC1) is identified in chemo-immunotherapy. A co-signature of cDC1 and CD8 correlates with cancer patient survival after neoadjuvant Pembrolizumab plus chemotherapy in clinic. This study highlights spatial cooperativity of chemo- and immuno-agents in immunoregulation and provides insights into the rational design of drug combination for future nanotherapeutics development.

A Functional "Key" Amplified Piezoelectric Effect Modulates ROS Storm with an Open Source for Multimodal Synergistic Cancer Therapy

Chemodynamic therapy (CDT) is a non-invasive strategy for generating reactive oxygen species (ROS) and is promising for cancer treatment. However, increasing ROS in tumor therapy remains challenging. Therefore, exogenous excitation and inhibition of electron-hole pair recombination are attractive for modulating ROS storms in tumors. Herein, a Ce-doped BiFeO3 (CBFO) piezoelectric sonosensitizer to modulate ROS generation and realize a synergistic mechanism of CDT/sonodynamic therapy and piezodynamic therapy (PzDT) is proposed. The mixed Fe2+ and Ce3+ can implement a circular Fenton/Fenton-like reaction in the tumor microenvironment. Abundant ·OH can be generated by ultrasound (US) stimulation to enhance CDT efficacy. As a typical piezoelectric sonosensitizer, CBFO can produce O2 - owing to the enhanced polarization by the US, resulting in the motion of charge carriers. In addition, CBFO can produce a piezoresponse irradiated upon US, which accelerates the migration rate of electrons/holes in opposite directions and results in energy band bending, further achieving toxic ROS production and realizing PzDT. Density functional theory calculations confirmed that Ce doping shortens the diffusion of electrons and improves the conductivity and catalytic activity of CBFO. This distinct US-enhanced strategy emphasizes the effects of doping engineering and piezoelectric-optimized therapy and shows great potential for the treatment of malignant tumors.

A Fe(III) intercalated clay nanoplatform for combined chemo/chemodynamic therapy

A Fe(III) intercalated montmorillonite nanoplatform (Fe-MMT) was engineered for doxorubicin (DOX) loading. The constructed Fe-MMT/DOX nanoplatform could not only improve the production of H2O2 to enhance chemodynamic therapy but interfere with DNA damage repair to amplify the efficacy of DOX, proving an ideal combination of chemotherapy and chemodynamic therapy.

Topical drug delivery strategies for enhancing drug effectiveness by skin barriers, drug delivery systems and individualized dosing

Topical drug delivery is widely used in various diseases because of the advantages of not passing through the gastrointestinal tract, avoiding gastrointestinal irritation and hepatic first-pass effect, and reaching the lesion directly to reduce unnecessary adverse reactions. The skin helps the organism to defend itself against a huge majority of external aggressions and is one of the most important lines of defense of the body. However, the skin's strong barrier ability is also a huge obstacle to the effectiveness of topical medications. Allowing the bioactive, composition in a drug to pass through the stratum corneum barrier as needed to reach the target site is the most essential need for the bioactive, composition to exert its therapeutic effect. The state of the skin barrier, the choice of delivery system for the bioactive, composition, and individualized disease detection and dosing planning influence the effectiveness of topical medications. Nowadays, enhancing transdermal absorption of topically applied drugs is the hottest research area. However, enhancing transdermal absorption of drugs is not the first choice to improve the effectiveness of all drugs. Excessive transdermal absorption enhances topical drug accumulation at non-target sites and the occurrence of adverse reactions. This paper introduces topical drug delivery strategies to improve drug effectiveness from three perspectives: skin barrier, drug delivery system and individualized drug delivery, describes the current status and shortcomings of topical drug research, and provides new directions and ideas for topical drug research.

Engineering Heterogeneous Tumor Models for Biomedical Applications

Tumor tissue engineering holds great promise for replicating the physiological and behavioral characteristics of tumors in vitro. Advances in this field have led to new opportunities for studying the tumor microenvironment and exploring potential anti-cancer therapeutics. However, the main obstacle to the widespread adoption of tumor models is the poor understanding and insufficient reconstruction of tumor heterogeneity. In this review, the current progress of engineering heterogeneous tumor models is discussed. First, the major components of tumor heterogeneity are summarized, which encompasses various signaling pathways, cell proliferations, and spatial configurations. Then, contemporary approaches are elucidated in tumor engineering that are guided by fundamental principles of tumor biology, and the potential of a bottom-up approach in tumor engineering is highlighted. Additionally, the characterization approaches and biomedical applications of tumor models are discussed, emphasizing the significant role of engineered tumor models in scientific research and clinical trials. Lastly, the challenges of heterogeneous tumor models in promoting oncology research and tumor therapy are described and key directions for future research are provided.

Enhancing Cancer Chemo-Immunotherapy: Innovative Approaches for Overcoming Immunosuppression by Functional Nanomaterials

Chemotherapy is a critical modality in cancer therapy to combat malignant cell proliferation by directly attacking cancer cells and inducing immunogenic cell death, serving as a vital component of multi-modal treatment strategies for enhanced therapeutic outcomes. However, chemotherapy may inadvertently contribute to the immunosuppression of the tumor microenvironment (TME), inducing the suppression of antitumor immune responses, which can ultimately affect therapeutic efficacy. Chemo-immunotherapy, combining chemotherapy and immunotherapy in cancer treatment, has emerged as a ground-breaking approach to target and eliminate malignant tumors and revolutionize the treatment landscape, offering promising, durable responses for various malignancies. Notably, functional nanomaterials have substantially contributed to chemo-immunotherapy by co-delivering chemo-immunotherapeutic agents and modulating TME. In this review, recent advancements in chemo-immunotherapy are thus summarized to enhance treatment effectiveness, achieved by reversing the immunosuppressive TME (ITME) through the exploitation of immunotherapeutic drugs, or immunoregulatory nanomaterials. The effects of two-way immunomodulation and the causes of immunoaugmentation and suppression during chemotherapy are illustrated. The current strategies of chemo-immunotherapy to surmount the ITME and the functional materials to target and regulate the ITME are discussed and compared. The perspective on tumor immunosuppression reversal strategy is finally proposed.

Designing Bioorthogonal Reactions for Biomedical Applications

Bioorthogonal reactions are a class of chemical reactions that can be carried out in living organisms without interfering with other reactions, possessing high yield, high selectivity, and high efficiency. Since the first proposal of the conception by Professor Carolyn Bertozzi in 2003, bioorthogonal chemistry has attracted great attention and has been quickly developed. As an important chemical biology tool, bioorthogonal reactions have been applied broadly in biomedicine, including bio-labeling, nucleic acid functionalization, drug discovery, drug activation, synthesis of antibody-drug conjugates, and proteolysis-targeting chimeras. Given this, we summarized the basic knowledge, development history, research status, and prospects of bioorthogonal reactions and their biomedical applications. The main purpose of this paper is to furnish an overview of the intriguing bioorthogonal reactions in a variety of biomedical applications and to provide guidance for the design of novel reactions to enrich bioorthogonal chemistry toolkits.

A Novel pH-Responsive Iron Oxide Core-Shell Magnetic Mesoporous Silica Nanoparticle (M-MSN) System Encapsulating Doxorubicin (DOX) and Glucose Oxidase (Gox) for Pancreatic Cancer Treatment

Introduction

This study developed a pancreatic cancer targeted drug delivery system that responds to changes in acidity. The system was based on iron oxide core-shell magnetic mesoporous silica nanoparticles (M-MSNs) to treat pancreatic cancer through combined chemotherapy and starvation therapy.

Methods

Glucose oxidase (Gox) was coupled to the cancer cell surface to reduce glucose availability for cancer cells, exacerbating the heterogeneity of the tumor microenvironment. Reduced pH accelerated the depolymerization of pH-sensitive polydopamine (PDA), thereby controlling the spatial distribution of Gox and release of doxorubicin (DOX) within tumor cells.

Results

Characterization results showed the successful synthesis of DG@M-MSN-PDA-PEG-FA (DG@NPs) with a diameter of 66.02 ± 3.6 nm. In vitro data indicated DG@NPs were highly effective and stable with good cellular uptake shown by confocal laser scanning microscopy (CLSM). DG@NPs exhibited high cytotoxicity and induced apoptosis. Additionally, in vivo experiments confirmed DG@NPs effectively inhibited tumor growth in nude mice with good biosafety. The combination of starvation therapy and chemotherapy facilitated drug release, suggesting DG@NPs as a novel drug delivery system for pancreatic cancer treatment.

Conclusion

This study successfully constructed a doxorubicin release system responsive to acidity changes for targeted delivery in pancreatic cancer, providing a new strategy for combination therapy.

Multi-Bioinspired MOF Delivery Systems from Microfluidics for Tumor Multimodal Therapy

Metal-organic framework (MOF)-based drug delivery systems have demonstrated values in oncotherapy. Current research endeavors are centralized on the functionality enrichment of featured MOF materials with designed versatility for synergistic multimodal treatments. Here, inspired by the multifarious biological functions including ferroptosis pattern, porphyrins, and cancer cell membrane (CCM) camouflage technique, novel multi-biomimetic MOF nanocarriers from microfluidics are prepared. The Fe3+ , meso-tetra(4-carboxyphenyl)porphine and oxaliplatin prodrug are incorporated into one MOF nano-system (named FeTPt), which is further cloaked by CCM to obtain a "Trojan Horse"-like vehicle (FeTPt@CCM). Owing to the functionalization with CCM, FeTPt@CCM can target and accumulate at the tumor site via homologous binding. After being internalized by cancer cells, FeTPt@CCM can be activated by a Fenton-like reaction as well as a redox reaction between Fe3+ and glutathione and hydrogen peroxide to generate hydroxyl radical and oxygen. Thus, the nano-platform effectively initiates ferroptosis and improves photodynamic therapy performance. Along with the Pt-drug chemotherapy, the nano-platform exhibits synergistic multimodal actions for inhibiting cancer cell proliferation in vitro and suppressing tumor growth in vivo. These features indicate that such a versatile biomimetic MOF delivery system from microfluidics has great potential for synergistic cancer treatment.

Advancements in pH-responsive nanocarriers: enhancing drug delivery for tumor therapy

INTRODUCTION

Tumors pose a significant global economic and health burden, with conventional cancer treatments lacking tumor specificity, leading to limited efficiency and undesirable side effects. Targeted tumor therapy is imminent. Tumor cells produce lactate and hydrogen ions (H+) by Warburg effect, forming an acidic tumor microenvironment (TME), which can be employed to design targeted tumor therapy. Recently, progress in nanotechnology has led to the development of pH-responsive nanocarriers, which have gathered significant attention. Under acidic tumor conditions, they exhibit targeted accumulation within tumor sites and controlled release profiles of therapeutic reagents, enabling precise tumor therapy.

AREAS COVERED

This review comprehensively summarize the principles underlying pH-responsive features, discussing various types of pH-responsive nanocarriers, their advantages, and limitations. Innovative therapeutic drugs are also examined, followed by an exploration of recent advancements in applying various pH-responsive nanocarriers as delivery systems for enhanced tumor therapy.

EXPERT OPINIONS

pH-responsive nanocarriers have garnered significant attention for their capability to achieve targeted accumulation of therapeutic agents at tumor sites and controlled drug delivery profiles, ultimately increasing the efficiency of tumor eradication. It is anticipated that the employment of pH-responsive nanocarriers will elevate the effectiveness and safety of tumor therapy, contributing to improved overall outcomes.

Cyclic RGD-Functionalized pH/ROS Dual-Responsive Nanoparticle for Targeted Breast Cancer Therapy

Breast cancer is the most common malignant tumor in women and is a big challenge to clinical treatment due to the high morbidity and mortality. The pH/ROS dual-responsive nanoplatforms may be an effective way to significantly improve the therapeutic efficacy of breast cancer. Herein, we report a docetaxel (DTX)-loaded pH/ROS-responsive NP that could achieve active targeting of cancer cells and selective and complete drug release for effective drug delivery. The pH/ROS-responsive NPs were fabricated using nanocarriers that consist of an ROS-responsive moiety (4-hydroxymethylphenylboronic acid pinacol ester, HPAP), cinnamaldehyde (CA, an aldehyde organic compound with anticancer activities) and cyclodextrin (α-CD). The NPs were loaded with DTX, modified with a tumor-penetration peptide (circular RGD, cRGD) and named DTX/RGD NPs. The cRGD could promote DTX/RGD NPs penetration into deep tumor tissue and specifically target cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, the pH-responsive acetal was cleaved to release CA in the lysosomal acidic environment. Meanwhile, the high ROS in tumor cells induced the disassembly of NPs with complete release of DTX. In vitro cellular assays verified that DTX/RGD NPs could be effectively internalized by 4T1 cells, obviously inducing apoptosis, blocking the cell cycle of 4T1 cells and consequently, killing tumor cells. In vivo animal experiments demonstrated that the NPs could target to the tumor sites and significantly inhibit the tumor growth in 4T1 breast cancer mice. Both in vitro and in vivo investigations demonstrated that DTX/RGD NPs could significantly improve the antitumor effect compared to free DTX. Thus, the DTX/RGD NPs provide a promising strategy for enhancing drug delivery and cancer therapy.

Atherosclerosis treatment with nanoagent: potential targets, stimulus signals and drug delivery mechanisms

Cardiovascular disease (CVDs) is the first killer of human health, and it caused up at least 31% of global deaths. Atherosclerosis is one of the main reasons caused CVDs. Oral drug therapy with statins and other lipid-regulating drugs is the conventional treatment strategies for atherosclerosis. However, conventional therapeutic strategies are constrained by low drug utilization and non-target organ injury problems. Micro-nano materials, including particles, liposomes, micelles and bubbles, have been developed as the revolutionized tools for CVDs detection and drug delivery, specifically atherosclerotic targeting treatment. Furthermore, the micro-nano materials also could be designed to intelligently and responsive targeting drug delivering, and then become a promising tool to achieve atherosclerosis precision treatment. This work reviewed the advances in atherosclerosis nanotherapy, including the materials carriers, target sites, responsive model and treatment results. These nanoagents precisely delivery the therapeutic agents to the target atherosclerosis sites, and intelligent and precise release of drugs, which could minimize the potential adverse effects and be more effective in atherosclerosis lesion.

Current Principles, Challenges, and New Metrics in pH-Responsive Drug Delivery Systems for Systemic Cancer Therapy

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

Esterase-Activated, pH-Responsive, and Genetically Targetable Nano-Prodrug for Cancer Cell Photo-Ablation

Activatable prodrugs have drawn considerable attention for cancer cell ablation owing to their high specificity in drug delivery systems. However, phototheranostic prodrugs with dual organelle-targeting and synergistic effects are still rare due to low intelligence of their structures. Besides, the cell membrane, exocytosis, and diffusional hindrance by the extracellular matrix reduce drug uptake. Moreover, the up-regulation of heat shock protein and short singlet-oxygen lifetime in cancer cells hamper photo-ablation efficacy, especially in the mono-therapeutic model. To overcome those obstacles, we prepare an esterase-activated DM nano-prodrug, which is conjugated by diiodine-substituted fluorogenic malachite green derivative (MG-2I) and phototherapeutic agent DPP-OH via hydrolyzable ester linkage, having pH-responsiveness and genetically targetable activity for dual organelles-targeting to optimize photo-ablation efficacy. The DM nanoparticles (NPs) present improved pH-responsive photothermal/photodynamic property by the protonation of diethylaminophenyl units in acidic environment. More importantly, the MG-2I and DPP-OH moieties can be released from DM nano-prodrug through overexpressed esterase; then specifically target lysosomes and mitochondria in CT-26 Mito-FAP cells. Hence, near-infrared DM NPs can trigger parallel damage in dual-organelles with strong fluorescence and effective phototoxicity, thus inducing serious mitochondrial dysfunction and apoptotic death, showing excellent photo-ablation effect based on esterase-activated, pH-responsive, and genetically targetable activities.

Chemoimmunological Cascade Cancer Therapy Using Fluorine Assembly Nanomedicine

Classical chemotherapeutic drugs may cause immunogenic cell death (ICD), followed by activating CD8⁺ T cells to promote cell-mediated antitumor immune responses. However, CD8⁺ T cells become exhausted due to tumor antigens' continuous stimulation, creating a major obstacle to effectively suppressing tumor growth and metastasis. Here, we develop an approach of chemo-gene combinational nanomedicine to bridge and reprogram chemotherapy and immunotherapy. The dually loaded nanomedicine induces ICD in tumor cells through doxorubicin and reverses the antitumor effects of exhausted CD8⁺ T cells through the small interfering RNA. The synergistic chemo-gene and fluorine assembly nanomedicine enriched in reactive oxygen species and acid-sensitive bonds results in enhanced cancer immunotherapy to inhibit tumor growth and the lung metastasis of breast cancer in a mouse model of breast cancer and melanoma. This study provides an efficient strategy and insights into chemoimmunological cascade therapy for combating malignant metastatic tumors.

Camouflaged Virus-Like-Nanocarrier with a Transformable Rough Surface for Boosting Drug Delivery

Due to non-specific strong nano-bio interactions, it is difficult for nanocarriers with permanent rough surface to cross multiple biological barriers to realize efficient drug delivery. Herein, a camouflaged virus-like-nanocarrier with a transformable rough surface is reported, which is composed by an interior virus-like mesoporous SiO₂ nanoparticle with a rough surface (vSiO₂ ) and an exterior acid-responsive polymer. Under normal physiological pH condition, the spikes on vSiO₂ are hidden by the polymer shell, and the non-specific strong nano-bio interactions are effectively inhibited. While in the acidic tumor microenvironment, the nanocarrier sheds the polymer camouflage to re-expose its rough surface. So, the retention ability and endocytosis efficiency of the nanocarrier are great improved. Owing to it's the dynamically variable rough surface, the rationally designed nanocarrier exhibits extended blood-circulation-time and enhanced tumor accumulation.

Enzyme-catalyzed synthesis of selenium-doped manganese phosphate for synergistic therapy of drug-resistant colorectal cancer

BACKGROUND

The development of multidrug resistance (MDR) during postoperative chemotherapy for colorectal cancer substantially reduces therapeutic efficacy. Nanostructured drug delivery systems (NDDSs) with modifiable chemical properties are considered promising candidates as therapies for reversing MDR in colorectal cancer cells. Selenium-doped manganese phosphate (Se-MnP) nanoparticles (NPs) that can reverse drug resistance through sustained release of selenium have the potential to improve the chemotherapy effect of colorectal cancer.

RESULTS

Se-MnP NPs had an organic-inorganic hybrid composition and were assembled from smaller-scale nanoclusters. Se-MnP NPs induced excessive ROS production via Se-mediated activation of the STAT3/JNK pathway and a Fenton-like reaction due to the presence of manganese ions (Mn²⁺). Moreover, in vitro and in vivo studies demonstrated Se-MnP NPs were effective drug carriers of oxaliplatin (OX) and reversed multidrug resistance and induced caspase-mediated apoptosis in colorectal cancer cells. OX@Se-MnP NPs reversed MDR in colorectal cancer by down-regulating the expression of MDR-related ABC (ATP binding cassette) transporters proteins (e.g., ABCB1, ABCC1 and ABCG2). Finally, in vivo studies demonstrated that OX-loaded Se-MnP NPs significantly inhibited proliferation of OX-resistant HCT116 (HCT116/DR) tumor cells in nude mice.

CONCLUSIONS

OX@Se-MnP NPs with simple preparation and biomimetic chemical properties represent promising candidates for the treatment of colorectal cancer with MDR.

Introduction to the RSC Advances themed collection on Nanomaterials in drug delivery

Professor Hélder A. Santos and Dr Irina N. Savina introduce the RSC Advances themed collection on Nanomaterials in drug delivery.

Microfluidic Synthesis of the Tumor Microenvironment-Responsive Nanosystem for Type-I Photodynamic Therapy

Type I photosensitizers with aggregation-induced emission luminogens (AIE-gens) have the ability to generate high levels of reactive oxygen species (ROS), which have a good application prospect in cancer photodynamic therapy (PDT). However, the encapsulation and delivery of AIE molecules are unsatisfactory and seriously affect the efficiency of a practical therapy. Faced with this issue, we synthesized the metal-organic framework (MOF) in one step using the microfluidic integration technology and encapsulated TBP-2 (an AIE molecule) into the MOF to obtain the composite nanomaterial ZT. Material characterization showed that the prepared ZT had stable physical and chemical properties and controllable size and morphology. After being endocytosed by tumor cells, ZT was degraded in response to the acidic tumor microenvironment (TME), and then TBP-2 molecules were released. After stimulation by low-power white light, a large amount of •OH and H₂O₂ was generated by TBP-2 through type I PDT, thereby achieving a tumor-killing effect. Further in vitro cell experiments showed good biocompatibility of the prepared ZT. To the best of our knowledge, this report is the first on the microfluidic synthesis of multifunctional MOF for type I PDT in response to the TME. Overall, the preparation of ZT by the microfluidic synthesis method provides new insight into cancer therapy.