Metal-Organic Frameworks Nucleated by Silk Fibroin and Modified with Tumor-Targeting Peptides for Targeted Multimodal Cancer Therapy

Ru/Co-N,Zn-doped carbon nanocubes with multiple enzyme-like activities for high-efficiency glucose detection and self-supplying cascaded nanodrug in synergistic cancer therapy

Nanozyme technology is increasingly utilized in biosensing and biomedicine fields. To advancing this technology, it is pivotal for constructing high-quality nanozymes and expanding their multifunctional applications. Herein, Co nanoparticles embedded within N,Zn-doped carbon nanocubes (Co-N,Zn-CNCs) were facilely prepared by pyrolysis, followed by surface modification with Ru nanoparticles (termed Ru/Co-N,Zn-CNCs). The resultant material exhibited peroxidase (POD)-, catalase (CAT)- and glutathione oxidase (GSHOx)-mimic activities. After attachment of glucose oxidase (GOx), a bifunctional self-supply cascaded nanodrug system (Ru/Co-N,Zn-CNCs-GOx) was established. Specifically, the nanozyme based colorimetric sensor was constructed for visually glucose detection, showing a good linear relationship in a range of 10 to 2000 μM and a low detection limit of 0.61 μM. Further, the cascaded nanodrug exhibited high-efficiency for eradicating cancer cells by reactive oxygen species mediated chemodynamic therapy, hypoxia alleviation, and starvation therapy, coupled by realizing ferroptosis of the cancer cells. The versatile cascaded nanozyme shows potential applications in biosensing, cancer therapy, and beyond.

Enhanced pharmacokinetic approach for anastrozole via macromolecule-based silk fibroin nanoparticles incorporated in situ injectables for oestrogen-positive breast cancer therapy

Breast cancer (BC) is a substantial reason for cancer-related mortality among women across the globe. Anastrozole (ANS) is an effective orally administered hormonal therapy for oestrogen-positive (ER+) BC treatment. However, several side effects and pharmacokinetic limitations restricted the uses of ANS in BC therapy. Therefore, this investigation developed an in situ gelling injectable-loaded silk fibroin (SF)-ANS NPs, which offers sustained drug release and improved pharmacokinetic properties compared to conventional oral formulations at the targeted site. The optimised in situ gel (ISG) incorporated SF-ANS-NPs were developed, and the pharmacokinetic parameters were accessed in subcutaneous administration of NMU-induced Wistar albino rats. The results demonstrated that SF-ANS-NP-ISG exhibited a significantly higher Cmax, Tmax, and AUC compared to pure ANS suspension. In addition, tumour multiplicity (1.40 ± 0.66), tumour latency (75 ± 9.2 days), and incidence rate (90 ± 2.1%) were recorded, and post-treatment analysis reported a marked reduction in tumour volume and weight compared to positive control within 90 days of a single dose. The SF-ANS-NP-ISG treated group's histopathological assessment indicated a low-grade carcinoma, reduced epithelial hyperplasia, and haemorrhage in mammary tumour tissues compared to positive control. Thus, the SF-ANS-NPs-ISG investigated to overcome the pharmacokinetic limitations of ANS further exhibited targeted delivery and bioavailability compared to conventional dosage forms.

Zeolitic Imidazole Framework-8 Nanoparticles as an Alternative to Freund's Adjuvant for Klebsiella pneumoniae Recombinant Protein Vaccine

Vaccination represents a promising approach to combat resistant Klebsiella pneumoniae (KP). However, there is currently no licensed vaccine in the veterinary field. Outer membrane proteins have been proven to possess good immunogenicity, but Freund's adjuvant, which is commonly used to administer protein vaccines, has limitations such as a complicated formulation process as well as a tendency to cause pain and inflammation in animals. Here, we prepared a nano-vaccine based on zeolitic imidazolate framework-8 (ZIF-8)-encapsulated outer membrane protein PhoE and evaluated its efficiency in enhancing humoral and cellular immune responses in BALB/c mice. ZIF-8 nanoparticles rapidly delivered the protein antigen into dendritic cells and successfully activated them. In addition, significantly higher IgG antibody titers, cytokine levels, and splenocyte proliferation indices were founded in mice subcutaneously immunized with PhoE@ZIF-8 than in those receiving free PhoE alone. In a BALB/c mouse model, PhoE@ZIF-8 elicited a strong immune response with improved prophylactic efficacy against KP that was similar to the Freund's adjuvant-formulated vaccine. Based on the superiority of this nano-vaccine with good biocompatibility, inexpensive preparation and higher efficiency of delivering antigen into cells, ZIF-8 can serve as a promising replacement for Freund's adjuvant in research, with a prospective usage for vaccines against bacterial pathogens in the veterinary field.

A ZIF-8-based dual-modal smart responsive nanoplatform for overcoming radiotherapy resistance in advanced tumors

Radiation therapy is one of the core means of tumor treatment, playing an irreplaceable role in local control and radical treatment. However, radiotherapy resistance is one of the major challenges in current clinical practice. Tumor cells have a strong ability to repair DNA damage, which can effectively resist DNA double-strand breaks caused by X-rays, thus weakening the killing effect of radiotherapy. In addition, the complexity of the tumor microenvironment (TME) will further reduce the sensitivity of radiotherapy, leading to poor treatment results. With the rapid development of nanotechnology, the use of multi-modal combined therapy nanoplatforms has gradually become a new strategy to overcome radiotherapy resistance. These nanoplatforms achieve synergies by integrating multiple therapeutic approaches, such as radiation sensitization, photothermal therapy and chemotherapy. In this study, we utilized ZIF-8, a type of metal-organic framework, to simultaneously load ICG and rapamycin for X-ray sensitization and combined photothermal therapy. In this formulation, rapamycin enhances tumor cells' sensitivity to radiotherapy by inhibiting the mTOR signaling pathway, increasing DNA damage, regulating the cell cycle, and stimulating the STING pathway, which amplifies the tumor immune response. Meanwhile, ICG, as a photosensitizer, effectively converts light energy into heat, achieving tumor photothermal ablation. The modified drug-delivery system becomes a tumor-microenvironment-responsive smart carrier, increasing tumor cell uptake, prolonging retention at the tumor site, and achieving targeted drug delivery. It releases drugs in the specific tumor microenvironment, enhancing photothermal and radiotherapy sensitization effects. The results show that the smart dual-loaded nanoplatform effectively combines photothermal therapy and external-beam sensitization, reshapes the immunosuppressive tumor microenvironment and significantly inhibits tumor proliferation in the HepG2 subcutaneous xenograft model, demonstrating marked antitumor activity and good biosafety.

Dimethylcurcumin and Copper Sulfate-Loaded Silk Nanoparticles for Synergistic Therapy against Breast Cancer

Dimethylcurcumin (ASC-J9) is an organic active pharmaceutical ingredient with anti-inflammatory, antioxidant, and antitumor effects. However, its application has been significantly hindered by poor solubility in aqueous solutions, a short in vivo half-life, low bioavailability after oral administration, and limited accumulation and absorption in target areas. Nano-drug delivery systems can serve as drug carriers to enhance drug delivery, addressing these challenges with improved efficacy and reduced adverse effects. In this study, a microfluidic swirl mixer is used to prepare silk fibroin composite nanoparticles containing ASC-J9 and copper sulfate (CuS), and the effects of different process parameters on silk fibroin nanoparticles (SNPs) were explored and optimized. The synthesized composite ASC-J9-CuS@SNPs exhibited a mean particle diameter of 180 ± 10 nm and PDI of 0.20 ± 0.03. Two-dimensional/three-dimensional (2D/3D) cell experiments showed that the composite nanomaterials have excellent biocompatibility and antitumor activity with a noticeable cancer cell specificity. In vivo experiments showed that ASC-J9-CuS@SNPs effectively controlled tumor growth without causing damage to blood cells and vital organs. Both in vitro and in vivo experiments demonstrated that the anticancer effect was enhanced by photo thermotherapy. The current study provides a promising strategy for using silk fibroin as nanocarriers for breast cancer therapy.

Evodiamine encapsulated by hyaluronic acid modified zeolitic imidazolate framework-8 for tumor targeted therapy

Evodiamine (EVO), a natural bioactive compound extracted from Evodia rutaecarpa, shows therapeutic ability against malignant melanoma. However, the poor solubility and bioavailability of EVO limit its clinical application. Metal-organic frameworks (MOFs) have shown excellent physical and chemical properties and are widely used as drug delivery systems. Among them, zeolitic imidazolate framework-8 (ZIF-8) is a research popular material because of its unique properties, such as hydrothermal stability, non-toxicity, biocompatibility, and pH sensitivity. In this study, in order to load EVO, a drug carrier that hyaluronic acid (HA) modified zeolitic imidazolate framework-8 (ZIF-8) is synthesized. This drug carrier has shown drug loading with 6.2 ± 0.6%, and the nano drugs (EVO@ZIF-8/HA) have good dispersibility. Owing to the decoration HA of EVO@ZIF-8, the potential of the nano drugs is reversed from the positive charge to the negative charge, which is beneficial to blood circulation in vivo. Furthermore, because the CD44-expressing in tumor cells is excessed, the endocytosis and accumulation of nano drugs in tumor cells are beneficial to improvement. Compared with free EVO, EVO@ZIF-8/HA has shown a significantly improved anti-tumor efficacy in vitro and in vivo. In summary, the drug carrier effectively addresses the challenges that are caused by the strong hydrophobicity and low bioavailability of EVO, thereby targeted tumor therapy of EVO can be achieved.

Advances in nanotechnology for targeting cancer-associated fibroblasts: A review of multi-strategy drug delivery and preclinical insights

Cancer-associated fibroblasts (CAFs) play a crucial role in the tumor microenvironment by promoting tumor growth, immune evasion, and metastasis. Recently, drug delivery systems targeting CAFs have emerged as a promising long-term and effective approach to cancer treatment. Advances in nanotechnology, in particular, have led to the development of nanomedicine delivery systems designed specifically to target CAFs, offering new possibilities for precise and personalized cancer therapies. This article reviews recent progress in drug delivery using nanocarriers that target CAFs. Additionally, we explore the potential of combining multiple therapies, such as chemotherapy and immunotherapy, with nanocarriers to enhance efficacy and overcome drug resistance. Although many preclinical studies show promise, the clinical application of nanomedicine still faces considerable challenges, especially in terms of drug penetration and large-scale production. Therefore, this review aims to provide a fresh perspective on CAF-targeted drug delivery systems and highlight potential future research directions and clinical applications.

Gold nanorods coated with self-assembled silk fibroin for improving their biocompatibility and facilitating targeted photothermal-photodynamic cancer therapy

Gold nanorods (AuNRs) have shown great potential as photothermal agents for cancer therapy. However, the biosafety of AuNRs ordinarily synthesized using a cationic ligand assistance procedure has always been a subject of controversy, which limits their application in tumor therapy. In this study, we propose a novel strategy to enhance the biocompatibility of AuNRs by constructing a biological coating derived from silk fibroin (SF) on their surface. The SF coating could be easily and precisely manipulated using a layer-by-layer (LBL) assembly method. The resulting SF-coated gold nanorods (AuNRs@SF) exhibited reduced cytotoxicity and improved hemocompatibility compared to untreated AuNRs. Moreover, the treated nanorods were easily modified with a tumor-targeting peptide (AuNRs@MTSF) and efficiently loaded indocyanine green (ICG). Both in vitro and in vivo analyses demonstrated that AuNRs@MTSF could more effectively reach tumor tissue and enter MCF-7 cells. Furthermore, after loading ICG, AuNRs@MTSF exhibited superior antitumor efficacy compared to other groups by combining photodynamic therapy (PDT) with photothermal therapy (PTT) under near-infrared (NIR) irradiation without inducing any side effects. This work suggests that SF coating of gold nanorods is a potential approach for improving their biocompatibility, and that function-modified AuNRs@SF are effective nanoplatforms for targeted and multimodal tumor therapy.

Remodeling tumor microenvironment using prodrug nMOFs for synergistic cancer therapy

Metal-organic frameworks (MOFs) hold tremendous potential in cancer therapy due to their remarkable structural and functional adaptability, enabling them to serve as nanocarriers for biopharmaceuticals and nanoreactors for organizing cascade bioreactions. Nevertheless, MOFs are predominantly utilized as biologically inactive carriers in most cases. Developing nanoscale prodrug MOFs suitable for biomedical applications remains a huge challenge. In this study, we have designed a novel prodrug nano-MOFs (nMOFs, named DCCMH) using metformin (Met) and α-cyano-4-hydroxycinnamic acid (CHCA) as ligands for coordination self-assembly with CuCl2, followed by loading of doxorubicin (DOX) and surface modification with hyaluronic acid (HA). Upon internalization by cancer cells, DCCMH releases Cu2+/+, CHCA, Met, and DOX in response to high levels of glutathione (GSH) and hydrogen peroxide (H2O2) within the tumor microenvironment (TME); Cu+ catalyzes the conversion of H2O2 to ·OH via the Fenton reaction while it was oxidized to Cu2+, which was subsequently further de-consumed of GSH; CHCA induces a further decrease in intracellular pH and promotes Fenton reactions by inhibiting lactate efflux; Met up-regulates tyrosine kinase activity and enhances the chemotherapy of DOX. With the ability to synergistically combine chemo/chemodynamic therapy (CT/CDT) and remodel the TME, the DCCMH NPs inhibit murine hepatoma effectively. This study presents a feasible strategy for fabricating prodrug nMOFs which are capable of remodeling TME to improve efficacy through synergistic cancer therapy.

Biomedical Applications of Metal-Organic Frameworks Revisited

Metal-organic frameworks (MOFs) have been shown to be great alternatives to traditional porous materials in various chemical applications, and they have been very widely studied for biomedical applications in the past decade specifically for drug storage. After our review published in 2011 [Keskin and Kızılel, Ind. Eng. Chem. Res. 2011, 50 (4), 1799-1812, 10.1021/ie101312k], we have witnessed a very fast growth not only in the number and variety of MOFs but also in their usage across a broad spectrum of biomedical fields. With the recent integration of molecular modeling and data science approaches to the experimental studies, biomedical applications of MOFs have been significantly accelerated positioning them as pivotal components in the regenerative medicine, medical imaging, and diagnostics. In this review, we visited the diverse biomedical applications of MOFs considering the recent experimental and computational efforts on drug storage and delivery, bioimaging, and biosensing. We focused on the underlying mechanisms governing the molecular interactions between MOFs and biological systems and discussed both the opportunities and challenges in the field to highlight the potential of MOFs in advanced therapeutics for cancer and neurological diseases.

Recent Advances in Indocyanine Green-Based Probes for Second Near-Infrared Fluorescence Imaging and Therapy

Fluorescence imaging, a highly sensitive molecular imaging modality, is being increasingly integrated into clinical practice. Imaging within the second near-infrared biological window (NIR-II; 1,000 to 1,700 nm), also referred to as shortwave infrared, has received substantial attention because of its markedly reduced autofluorescence, deeper tissue penetration, and enhanced spatiotemporal resolution as compared to traditional near-infrared (NIR) imaging. Indocyanine green (ICG), a US Food and Drug Administration-approved NIR fluorophore, has long been used in clinical applications, including blood vessel angiography, vascular perfusion monitoring, and tumor detection. Recent advancements in NIR-II imaging technology have revitalized interest in ICG, revealing its extended tail fluorescence beyond 1,000 nm and reaffirming its potential as a clinically translatable NIR-II fluorophore for in vivo imaging and theranostic applications for diagnosing various diseases. This review emphasizes the notable advances in the use of ICG and its derivatives for NIR-II imaging and image-guided therapy from both fundamental and clinical perspectives. We also provide a concise conclusion and discuss the challenges and future opportunities with NIR-II imaging using clinically approved fluorophores.

Biomaterials enhancing localized cancer therapy activated anti-tumor immunity: a review

Localized cancer therapies such as radiotherapy, phototherapy, and chemotherapy are precise cancer treatment strategies aimed at minimizing systemic side effects. However, cancer metastasis remains the primary cause of mortality among cancer patients in clinical settings, and localized cancer treatments have limited efficacy against metastatic cancer. Therefore, researchers are exploring strategies that combine localized therapy with immunotherapy to activate robust anti-tumor immune responses, thereby eradicating metastatic cancer. Biomaterials, as novel materials, exhibit great potential in biomedical applications and have achieved great progress in clinic translation. This review introduces biomaterials and their applications in research focused on enhancing localized cancer treatment activated anti-tumor immunity. Additionally, the current challenges and future directions of biomaterials are also discussed, providing insights and references for related research.

Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers: From Synthesis to Cancer Therapy and Biomedical Imaging

Recently, there has been significant interest in nanoscale metal-organic frameworks (NMOFs) characterized by ordered crystal structures and nanoscale coordination polymers (NCPs) featuring amorphous structures. These structures arise from the coordination interactions between inorganic metal ions or clusters and organic ligands. Their advantages, such as the ability to tailor composition and structure, efficiently encapsulate diverse therapeutic or imaging agents within porous frameworks, inherent biodegradability, and surface functionalization capability, position them as promising carriers in the biomedical fields. This review provides an overview of the synthesis and surface modification strategies employed for NMOFs and NCPs, along with their applications in cancer treatment and biological imaging. Finally, future directions and challenges associated with the utilization of NMOFs and NCPs in cancer treatment and diagnosis are also discussed.

Recognition of MCF-7 breast cancer cells using native collagen probes: Collagen source effect

Developing superior cancer cell recognition probes is crucial for the development of tumor therapy and cancer early screening materials. In this study, we first achieved effective recognition of MCF-7 breast cancer cells using natural collagen probes. Through cell adhesion, cancer cell selective capture, and flow cytometry techniques, the binding efficiency of mammalian-derived collagens (bovine Achilles tendon collagen, porcine skin collagen) and fish-derived collagens (turbot skin collagen, grass carp skin collagen, mandarin fish skin collagen) to cancer cells (MCF-7 breast cancer cells) and normal cells (human umbilical vein endothelial cells, HUVECs) was analyzed and compared. The feasibility of different source collagens as probes for recognition of MCF-7 cells was explored in vitro. The results indicated that mammalian-derived collagens had a superior advantage over fish-derived collagens in recognizing MCF-7 cells, with bovine Achilles tendon collagen achieving a capture rate of up to 64.7 % in a multicellular co-culture system. Furthermore, in vivo imaging of BALB/c tumor-bearing mice confirmed the high-efficiency targeted recognition performance of the bovine Achilles tendon collagen probe for MCF-7 cells.

Preparation of carboxylated-silk nanofibers by the one-pot method of maleic acid hydrolysis

In this study, a maleic acid (MA) hydrolysis one-pot method is proposed to prepare carboxylated silk nanofibers (MA-SNFs). The MA concentration, hydrolysis temperature, and processing time were optimized. Combined with high-pressure homogenization, MA-SNFs with a carboxyl content of 0.617±0.019 mmol/g and length of 333±116 nm were obtained with a yield of 54.90±1.98 % at the optimal conditions: 50 wt% of MA concentration, 110 °C of hydrolysis temperature and 120 min of processing time. The morphology, chemical structure, and crystal structure of raw silk fibroin (SF), acid-hydrolyzed silk fibroin and nanofibers were studied. Furthermore, MA was reused several times with a recovery rate of >94 % and maintained almost the same treatment effect. Finally, due to the presence of carboxyl groups, MA-SNF hydrogels were successfully prepared by an acetic coagulation vapor bath which exhibited excellent self-supporting ability and mechanical properties as well as a more sensitive pH response compared with regenerated silk fibroin solution and other non-carboxylated silk nanofibers. The MA-SNF aerogels had the characteristics of light weight, high strength and porous with cross-linked nanostructures.

Electrospinning Aligned SF/Magnetic Nanoparticles-Blend Nanofiber Scaffolds for Inducing Skeletal Myoblast Alignment and Differentiation

In the realm of skeletal muscle tissue engineering, anisotropic materials that emulate natural tissues show substantial promise. Electrospun scaffolds, mimicking the fibrillar structure of the extracellular matrix, are commonly employed but often fall short in achieving optimal alignment and mechanical strength. Silk fibroin has emerged as a versatile material in tissue engineering, valued for its biocompatibility, mechanical robustness, and biodegradability. However, conventional electrospinning methods of SF result in randomly oriented fibers, limiting their efficacy. In this work, we developed a straightforward method to fabricate directional tissue scaffolds using silk fibroin. By integrating a magnetic field collecting device and incorporating Fe3O4 nanoparticles into the spinning solution, we successfully produced well-aligned silk nanofiber scaffolds. These aligned fibers not only improved scaffold orientation and mechanical properties but also exhibited magnetic responsiveness. The aligned SF scaffolds effectively guided the adhesion, proliferation, and differentiation of mesenchymal stem cells along the fiber direction. Cultured on these scaffolds, myoblast C2C12 cells demonstrated oriented growth, highlighting the potential of aligned SF fibers in advancing skeletal muscle engineering for biomedical applications.

Metal-Organic Frameworks (MOFs): Classification, Synthesis, Modification, and Biomedical Applications

Metal-organic frameworks (MOFs) are a new variety of solid crystalline porous functional materials. As an extension of inorganic porous materials, it has made important progress in preparation and application. MOFs are widely used in various fields such as gas adsorption storage, drug delivery, sensing, and biological imaging due to their high specific surface area, porosity, adjustable pore size, abundant active sites, and functional modification by introducing groups. In this paper, the types of MOFs are classified, and the synthesis methods and functional modification mechanisms of MOFs materials are summarized. Finally, the application prospects and challenges of metal-organic framework materials in the biomedical field are discussed, hoping to promote their application in multidisciplinary fields.

A Multifunctional Biomimetic Nanoplatform for Dual Tumor Targeting-Assisted Multimodal Therapy of Colon Cancer

The biomimetic nanoparticles (NPs) possessing abilities of tumor targeting and multimodal therapy show great potential for efficient combat of colon cancer. Herein, we developed a multifunctional biomimetic nanoplatform (Fe3O4@PDA@CaCO3-ICG@CM) based on CaCO3-modified magnetic polydopamine (PDA) loaded with indocyanine green (ICG), which was encapsulated by a mouse lymphoma cell (EL4) membrane (CM) expressing functional proteins (i.e., lymphocyte function-associated antigen 1, LFA-1; transforming growth factor-β receptor, TGF-βR; programmed cell death protein 1, PD-1; and factor related apoptosis ligand, FasL). Under magnetic attraction and LFA-1/PD-1-mediated endocytosis, Fe3O4@PDA@CaCO3-ICG@CM efficiently targeted CT26 colon tumor cells. The released calcium ion (Ca2+) from the NPs triggered by acidic tumor microenvironment, the enhanced photothermal effect contributed by the combination of PDA and ICG, and FasL's direct killing effect together induced tumor cells apoptosis. Moreover, the apoptosis of CT26 cells induced immunogenic cell death (ICD) to promote the maturation of dendritic cells (DCs) to activate CD4+/CD8+ T cells, thereby fighting against tumor cells, which could further be boosted by programmed death-ligand 1 (PD-L1) blockage and transforming growth factor-β (TGF-β) scavenging by Fe3O4@PDA@CaCO3-ICG@CM. As a result, in vivo satisfactory therapeutic effect was observed for CT26 tumor bearing-mice treated with Fe3O4@PDA@CaCO3-ICG@CM under laser irradiation and magnetic attraction, which could eradicate primary tumors and restrain distant tumors through dual tumor targeting-assisted multimodal therapy and eliciting adaptive antitumor immune response, generating the immune memory for inhibiting tumor metastasis and recurrence. Taken together, the multifunctional biomimetic nanoplatform exhibits superior antitumor effects, providing an insightful strategy for the field of nanomaterial-based treatment of cancer.

Integrated design and application of stimuli-responsive metal-organic frameworks in biomedicine: current status and future perspectives

In recent years, metal-organic frameworks (MOFs) have garnered widespread attention due to their distinctive attributes, such as high surface area, tunable properties, biodegradability, extremely low density, high loading capacity, diverse chemical functionalities, thermal stability, well-defined pore sizes, and molecular dimensions. Increasingly, biomedical researchers have turned their focus towards their multifaceted development. Among these, stimuli-responsive MOFs, with their unique advantages, have captured greater interest from researchers. This review will delve into the merits and drawbacks of both endogenous and exogenous stimuli-responsive MOFs, along with their application directions. Furthermore, it will outline the characteristics of different synthesis routes of MOFs, exploring various design schemes and modification strategies and their impacts on the properties of MOF products, as well as how to control them. Additionally, we will survey different types of stimuli-responsive MOFs, discussing the significance of various MOF products reported in biomedical applications. We will categorically summarize different strategies such as anticancer therapy, antibacterial treatment, tissue repair, and biomedical imaging, as well as insights into the development of novel MOFs nanomaterials in the future. Finally, this review will conclude by summarizing the challenges in the development of stimuli-responsive MOFs in the field of biomedicine and providing prospects for future research endeavors.

A Self-Delivery Nanodrug Simultaneously Inhibits COX-2/PGE2 Mediated Inflammation and Downregulates PD-L1 to Boost Photoimmunotherapy

Phototherapy promotes anti-tumor immunity by inducing immunogenic cell death (ICD), However, the accompanying inflammatory responses also trigger immunosuppression, attenuating the efficacy of photo-immunotherapy. Herein, they co-assembled a cell-membrane targeting chimeric peptide C16-Cypate-RRKK-PEG8-COOH (CCP) and anti-inflammatory diclofenac (DA) to develop a nanodrug (CCP@DA) that both enhances the immune effect of phototherapy and weakens the inflammation-mediated immunosuppression. CCP@DA achieves cell membrane-targeting photodynamic and photothermal synergistic therapies to damage programmed death ligand 1 (PD-L1) and induce a strong ICD to activate anti-tumor response. Simultaneously, the released DA inhibits the cycoperoxidase-2 (COX-2)/prostaglandin E2 (PGE2) pathway in tumor cells to inhibit pro-tumor inflammation and further down-regulate PD-L1 expression to relieve the immunosuppressive microenvironment. CCP@DA significantly inhibited tumor growth and inflammation both in vitro and in vivo, while maintaining a potent anti-tumor immune response. Additionally, it exhibits excellent anti-metastatic capabilities and prolongs mouse survival time with a single dose and low levels of near-infrared (NIR) light exposure. This work provides a valuable strategy to control the therapy-induced inflammation for high-efficiency photoimmunotherapy.

Acid-Responsive Decomposable Nanomedicine Based on Zeolitic Imidazolate Frameworks for Near-Infrared Fluorescence Imaging/Chemotherapy Combined Tumor Theranostics

Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (NPs) are gaining traction in tumor theranostics for their effectiveness in encapsulating both imaging agents and therapeutic drugs. While typically, similar hydrophilic molecules are encapsulated in either pure aqueous or organic environments, few studies have explored co-encapsulation of chemotherapeutic drugs and imaging agents with varying hydrophilicity and, consequently, constructed multifunctional ZIF-8 composite NPs for acid-responsive, near-infrared fluorescence imaging/chemotherapy combined tumor theranostics. Here, we present a one-pot method for the synthesis of uniform Cy5.5&DOX@ZIF-8 nanoparticles in mixed solvents, efficiently achieving simultaneous encapsulation of hydrophilic doxorubicin (DOX) and hydrophobic Cyanine-5.5 (Cy5.5). Surface decoration with dextran (Dex) enhanced colloidal stability and biocompatibility. The method significantly facilitated co-loading of Cy5.5 dyes and DOX drugs, endowing the composite NPs with notable fluorescent imaging capabilities and pH-responsive chemotherapy capacities. In vivo near-infrared fluorescence (NIRF) imaging in A549 tumor-bearing mice demonstrated significant accumulation of Cy5.5 at tumor sites due to enhanced permeability and retention (EPR) effects, with fluorescence intensities approximately 48-fold higher than free Cy5.5. Enhanced therapeutic efficiency was observed in composite NPs compared to free DOX, validating tumor-targeted capability. These findings suggest ZIF-8-based nanomedicines as promising platforms for multifunctional tumor theranostics.

A natural killer T cell nanoagonist-initiated immune cascade for hepatocellular carcinoma synergistic immunotherapy

Natural killer T (NKT) cell-mediated immunotherapy shows great promise in hepatocellular carcinoma featuring an inherent immunosuppressive microenvironment. However, targeted delivery of NKT cell agonists remains challenging. Here, we developed a hyaluronic acid (HA) modified metal organic framework (zeolitic imidazolate framework-8, ZIF-8) to encapsulate α-galactosylceramide (α-Galcer), a classic NKT cell agonist, and doxorubicin (DOX) for eliminating liver cancer, denoted as α-Galcer/DOX@ZIF-8@HA. In the tumor microenvironment (TME), these pH-responsive nano-frameworks can gradually collapse to release α-Galcer for activating NKT cells and further boosting other immune cells in order to initiate an antitumor immune cascade. Along with DOX, the released α-Galcer enabled efficient NKT cell activation in TME for synergistic immunotherapy and tumor elimination, leading to evident tumor suppression and prolonged animal survival in both subcutaneous and orthotopic liver tumor models. Manipulating NKT cell agonists into functional nano-frameworks in TME may be matched with other advanced managements applied in a wider range of cancer therapies.

Biomimetic ZIF-8 Nanoparticles: A Novel Approach for Biomimetic Drug Delivery Systems

Metal-organic frameworks (MOFs) are porous materials resulting from the coordination of metal clusters or ions with organic ligands, merging macromolecular and coordination chemistry features. Among these, zeolitic imidazolate framework-8 (ZIF-8) stands out as a widely utilized MOF known for its robust stability in aqueous environments owing to the robust interaction between its constituent zinc ions (Zn2+) and 2-methylimidazole (2-MIM). ZIF-8 readily decomposes under acidic conditions, serving as a promising candidate for pH-responsive drug delivery systems. Moreover, biomimetic materials typically possess good biocompatibility, reducing immune reactions. By mimicking natural structures or surface features within the body, they enhance the targeting of nanoparticles, prolong their circulation time, and increase their bioavailability in vivo. This review explores the latest advancements in biomimetic ZIF-8 nanoparticles for drug delivery, elucidating the primary obstacles and future prospects in utilizing ZIF-8 for drug delivery applications.

Different Targeting Ligands-Mediated Drug Delivery Systems for Tumor Therapy

Traditional tumor treatments have the drawback of harming both tumor cells and normal cells, leading to significant systemic toxic side effects. As a result, there is a pressing need for targeted drug delivery methods that can specifically target cells or tissues. Currently, researchers have made significant progress in developing targeted drug delivery systems for tumor therapy using various targeting ligands. This review aims to summarize recent advancements in targeted drug delivery systems for tumor therapy, focusing on different targeting ligands such as folic acid, carbohydrates, peptides, aptamers, and antibodies. The review also discusses the advantages, challenges, and future prospects of these targeted drug delivery systems.

Multifunctional ZnO@DOX/ICG-LMHP Nanoparticles for Synergistic Multimodal Antitumor Activity

Multifunctional nanoparticles are of significant importance for synergistic multimodal antitumor activity. Herein, zinc oxide (ZnO) was used as pH-sensitive nanoparticles for loading the chemotherapy agent doxorubicin (DOX) and the photosensitizer agent indocyanine green (ICG), and biocompatible low-molecular-weight heparin (LMHP) was used as the gatekeepers for synergistic photothermal therapy/photodynamic therapy/chemotherapy/immunotherapy. ZnO was decomposed into cytotoxic Zn2+ ions, leading to a tumor-specific release of ICG and DOX. ZnO simultaneously produced oxygen (O2) and reactive oxygen species (ROS) for photodynamic therapy (PDT). The released ICG under laser irradiation produced ROS for PDT and raised the tumor temperature for photothermal therapy (PTT). The released DOX directly caused tumor cell death for chemotherapy. Both DOX and ICG also induced immunogenic cell death (ICD) for immunotherapy. The in vivo and in vitro results presented a superior inhibition of tumor progression, metastasis and recurrence. Therefore, this study could provide an efficient approach for designing multifunctional nanoparticles for synergistic multimodal antitumor therapy.