Triple-negative breast cancer treatment with core-shell Magnetic@Platinium-Metal organic framework/epirubicin nano-platforms for chemo-photodynamic based combinational therapy: A review

The combination of chemotherapy and photodynamic therapy (PDT), enabled by core-shell nano-platforms, is a promising method to improve cancer therapy by overcoming hypoxia and boosting drug penetration in breast tumor. Core-shell magnetic (iron oxide: Fe3O4)@platinum-metal organic framework/epirubicin (abbreviated as M@Pt-MOF/EPI) nano-platform is considered an effective cancer therapeutic agent. Relatively small particle size, round shape, and specific response to pH, are the key features of these nanomaterials to be used as promising therapeutic agents. Chemotherapy and photodynamic therapy, when applied in addition to the anticancer effects of nanomaterials, further enhance the therapeutic efficacy. The extensive use, utilization, and efficacy of Core-Shell Magnetic@Platinium-Metal Organic Framework/epirubicin Nano-Platforms for chemo-photodynamic combination therapy in the treatment of several cancers, including triple-negative breast cancer, are examined in this in-depth investigation.

MOFs for next-generation cancer therapeutics through a biophysical approach-a review

Metal-organic frameworks (MOFs) have emerged as promising nanocarriers for cancer treatment due to their unique properties. Featuring high porosity, extensive surface area, chemical stability, and good biocompatibility, MOFs are ideal for efficient drug delivery, targeted therapy, and controlled release. They can be designed to target specific cellular organelles to disrupt metabolic processes in cancer cells. Additionally, functionalization with enzymes mimics their catalytic activity, enhancing photodynamic therapy and overcoming apoptosis resistance in cancer cells. The controllable and regular structure of MOFs, along with their tumor microenvironment responsiveness, make them promising nanocarriers for anticancer drugs. These carriers can effectively deliver a wide range of drugs with improved bioavailability, controlled release rate, and targeted delivery efficiency compared to alternatives. In this article, we review both experimental and computational studies focusing on the interaction between MOFs and drug, explicating the release mechanisms and stability in physiological conditions. Notably, we explore the relationship between MOF structure and its ability to damage cancer cells, elucidating why MOFs are excellent candidates for bio-applicability. By understanding the problem and exploring potential solutions, this review provides insights into the future directions for harnessing the full potential of MOFs, ultimately leading to improved therapeutic outcomes in cancer treatment.

An electrochemiluminescence sensor based on lanthanide bimetallic MOFs with a "cascade sensitization mechanism" for the sensitive detection of CA242

Lanthanide metal-organic frameworks (Ln-MOFs) broaden the optical sensing applications of lanthanide ions due to the antenna effect between organic ligands and metals. However, the sensitization ability of the ligand to metal ions is limited, and maximizing the sensitization of the electrochemiluminescence behavior of Eu3+ is still a challenge for the application of Ln-MOFs. Therefore, under the guidance of the "cascade sensitization mechanism" based on the antenna effect sensitizing the electrochemiluminescence of bimetallic Ln-MOFs, we proposed Eu/Tb-MOFs with high luminescence intensity as a signal probe. According to the antenna effect, the conjugated structure and high extinction coefficient of the benzene ring of 2-amino terephthalic acid (NH2-BDC) can enhance the ECL luminescence intensity of Eu/Tb-MOFs. Tb3+ can act as an energy bridge between NH2-BDC and Eu3+, buffering the energy gap. The bimetallic sensitization is formed between Tb3+ and Eu3+, which can inhibit the reverse internal flow of energy and ensure the high luminous efficiency of Eu3+. In addition, the nanosphere mixed valence Fe3O4 as a co-reactant accelerator promotes the formation of transient free radical SO4•- through the valence change of Fe2+/Fe3+. The ECL immunosensor constructed by luminophores Eu/Tb-MOFs and nanosphere Fe3O4 provided a new explanation for the ECL self-luminous of Eu/Tb-MOFs.

Homologous-magnetic dual-targeted metal-organic framework to improve the Anti-hepatocellular carcinoma efficacy of PD-1 inhibitor

The insufficient abundance and weak activity of tumour-infiltrating lymphocytes (TILs) are two important reasons for the poor efficacy of PD-1 inhibitors in hepatocellular carcinoma (HCC) treatment. The combined administration of tanshinone IIA (TSA) and astragaloside IV (As) can up-regulate the abundance and activity of TILs by normalising tumour blood vessels and reducing the levels of immunosuppressive factors respectively. For enhancing the efficacy of PD-1 antibody, a magnetic metal-organic framework (MOF) with a homologous tumour cell membrane (Hm) coating (Hm@TSA/As-MOF) is established to co-deliver TSA&As into the HCC microenvironment. Hm@TSA/As-MOF is a spherical nanoparticle and has a high total drug-loading capacity of 16.13 wt%. The Hm coating and magnetic responsiveness of Hm@TSA/As-MOF provide a homologous-magnetic dual-targeting, which enable Hm@TSA/As-MOF to counteract the interference posed by ascites tumour cells and enhance the precision of targeting solid tumours. Hm coating also enable Hm@TSA/As-MOF to evade immune clearance by macrophages. The release of TSA&As from Hm@TSA/As-MOF can be accelerated by HCC microenvironment, thereby up-regulating the abundance and activity of TILs to synergistic PD-1 antibody against HCC. This study presents a nanoplatform to improve the efficacy of PD-1 inhibitors in HCC, providing a novel approach for anti-tumour immunotherapy in clinical practice.

Nanocomposites Based on Magnetic Nanoparticles and Metal-Organic Frameworks for Therapy, Diagnosis, and Theragnostics

In the last two decades, metal-organic frameworks (MOFs) with highly tunable structure and porosity, have emerged as drug nanocarriers in the biomedical field. In particular, nanoscaled MOFs (nanoMOFs) have been widely investigated because of their potential biocompatibility, high drug loadings, and progressive release. To enhance their properties, MOFs have been combined with magnetic nanoparticles (MNPs) to form magnetic nanocomposites (MNP@MOF) with additional functionalities. Due to the magnetic properties of the MNPs, their presence in the nanosystems enables potential combinatorial magnetic targeted therapy and diagnosis. In this Review, we analyze the four main synthetic strategies currently employed for the fabrication of MNP@MOF nanocomposites, namely, mixing, in situ formation of MNPs in presynthesized MOF, in situ formation of MOFs in the presence of MNPs, and layer-by-layer methods. Additionally, we discuss the current progress in bioapplications, focusing on drug delivery systems (DDSs), magnetic resonance imaging (MRI), magnetic hyperthermia (MHT), and theragnostic systems. Overall, we provide a comprehensive overview of the recent advances in the development and bioapplications of MNP@MOF nanocomposites, highlighting their potential for future biomedical applications with a critical analysis of the challenges and limitations of these nanocomposites in terms of their synthesis, characterization, biocompatibility, and applicability.

Magnetic Metal-Organic Framework-Based Nanoplatform with Platelet Membrane Coating as a Synergistic Programmed Cell Death Protein 1 Inhibitor against Hepatocellular Carcinoma

Programmed cell death protein 1 (PD-1) inhibitors are the most common immune-checkpoint inhibitors and considered promising drugs for hepatocellular carcinoma (HCC). However, in clinical settings, they have a low objective response rate (15%-20%) for patients with HCC; this is because of the insufficient level and activity of tumor-infiltrating T lymphocytes (TILs). The combined administration of oxymatrine (Om) and astragaloside IV (As) can increase the levels of TILs by inhibiting the activation of cancer-associated fibroblasts (CAFs) and improve the activity of TILs by enhancing their mitochondrial function. In the present study, we constructed a magnetic metal-organic framework (MOF)-based nanoplatform with platelet membrane (Pm) coating (PmMN@Om&As) to simultaneously deliver Om and As into the HCC microenvironment. We observed that PmMN@Om&As exhibited a high total drug-loading capacity (33.77 wt %) and good immune escape. Furthermore, it can target HCC tissues in a magnetic field and exert long-lasting effects. The HCC microenvironment accelerated the disintegration of PmMN@Om&As and the release of Om&As, thereby increasing the level and activity of TILs by regulating CAFs and the mitochondrial function of TILs. In addition, the carrier could synergize with Om&As by enhancing the oxygen consumption rate and proton efflux rate of TILs, thereby upregulating the mitochondrial function of TILs. Combination therapy with PmMN@Om&As and α-PD-1 resulted in a tumor suppression rate of 84.15% and prolonged the survival time of mice. Our study provides a promising approach to improving the antitumor effect of immunotherapy in HCC.

Current status and prospects of MIL-based MOF materials for biomedicine applications

This article mainly reviews the biomedicine applications of two metal-organic frameworks (MOFs), MIL-100(Fe) and MIL-101(Fe). These MOFs have advantages such as high specific surface area, adjustable pore size, and chemical stability, which make them widely used in drug delivery systems. The article first introduces the properties of these two materials and then discusses their applications in drug transport, antibacterial therapy, and cancer treatment. In cancer treatment, drug delivery systems based on MIL-100(Fe) and MIL-101(Fe) have made significant progress in chemotherapy (CT), chemodynamic therapy (CDT), photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy (IT), nano-enzyme therapy, and related combined therapy. Overall, these MIL-100(Fe) and MIL-101(Fe) materials have tremendous potential and diverse applications in the field of biomedicine.

Advances in surface-modified nanometal-organic frameworks for drug delivery

Nanometal-organic frameworks (NMOFs) are porous network structures composed of metal ions or metal clusters through self-assembly. NMOFs have been considered as a promising nano-drug delivery system due to their unique properties such as pore and flexible structures, large specific surface areas, surface modifiability, non-toxic and degradable properties. However, NMOFs face a series complex environment during in vivo delivery. Therefore, surface functionalization of NMOFs is vital to ensure that the structure of NMOFs remain stable during delivery, and can overcome physiological barriers to deliver drugs more accurately to specific sites, and achieve controllable release. In this review, the first part summarizes the physiological barriers that NMOFs faced during drug delivery after intravenous injection and oral administration. The second part summarizes the current main ways to load drugs into NMOFs, mainly including pore adsorption, surface attachment, formation of covalent/coordination bonds between drug molecules and NMOFs, and in situ encapsulation. The third part is the main review part of this paper, which summarizes the surface modification methods of NMOFs used in recent years to overcome the physiological barriers and achieve effective drug delivery and disease therapy, which are mainly divided into physical modifications and chemical modifications. Finally, the full text is summarized and prospected, with the hope to provide ideas for the future development of NMOFs as drug delivery.

Systemic Tumor Suppression via Macrophage-Driven Automated Homing of Metal-Phenolic-Gated Nanosponges for Metastatic Melanoma

Cell-based therapies comprising the administration of living cells to patients for direct therapeutic activities have experienced remarkable success in the clinic, of which macrophages hold great potential for targeted drug delivery due to their inherent chemotactic mobility and homing ability to tumors with high efficiency. However, such targeted delivery of drugs through cellular systems remains a significant challenge due to the complexity of balancing high drug-loading with high accumulations in solid tumors. Herein, a tumor-targeting cellular drug delivery system (MAGN) by surface engineering of tumor-homing macrophages (Mφs) with biologically responsive nanosponges is reported. The pores of the nanosponges are blocked with iron-tannic acid complexes that serve as gatekeepers by holding encapsulated drugs until reaching the acidic tumor microenvironment. Molecular dynamics simulations and interfacial force studies are performed to provide mechanistic insights into the "ON-OFF" gating effect of the polyphenol-based supramolecular gatekeepers on the nanosponge channels. The cellular chemotaxis of the Mφ carriers enabled efficient tumor-targeted delivery of drugs and systemic suppression of tumor burden and lung metastases in vivo. The findings suggest that the MAGN platform offers a versatile strategy to efficiently load therapeutic drugs to treat advanced metastatic cancers with a high loading capacity of various therapeutic drugs.

Hydroxyapatite-based carriers for tumor targeting therapy

At present, targeted drug delivery is regarded as the most effective means of tumor treatment, overcoming the lack of conventional chemotherapeutics that are difficult to reach or enter into cancer cells. Hydroxyapatite (HAP) is the main component of biological hard tissue, which can be regarded as a suitable drug carrier due to its biocompatibility, nontoxicity, biodegradation, and absorbability. This review focuses on the cutting edge of HAP as a drug carrier in targeted drug delivery systems. HAP-based carriers can be obtained by doping, modification, and combination, which benefit to improve the loading efficiency of drugs and the response sensitivity of the microenvironment in the synthesis process. The drug adsorbed or in situ loaded on HAP-based carriers can achieve targeted drug delivery and precise treatment through the guidance of the in vivo microenvironment and the stimulation of the in vitro response. In addition, HAP-based drug carriers can improve the cellular uptake rate of drugs to achieve a higher treatment effect. These advantages revealed the promising potential of HAP-based carriers from the perspective of targeted drug delivery for tumor treatment.

Fe-Based Metal Organic Frameworks (Fe-MOFs) for Bio-Related Applications

Metal-organic frameworks (MOFs) are porous materials composed of metal ions and organic ligands. Due to their large surface area, easy modification, and good biocompatibility, MOFs are often used in bio-related fields. Fe-based metal-organic frameworks (Fe-MOFs), as important types of MOF, are favored by biomedical researchers for their advantages, such as low toxicity, good stability, high drug-loading capacity, and flexible structure. Fe-MOFs are diverse and widely used. Many new Fe-MOFs have appeared in recent years, with new modification methods and innovative design ideas, leading to the transformation of Fe-MOFs from single-mode therapy to multi-mode therapy. In this paper, the therapeutic principles, classification, characteristics, preparation methods, surface modification, and applications of Fe-MOFs in recent years are reviewed to understand the development trends and existing problems in Fe-MOFs, with the view to provide new ideas and directions for future research.

Fabrication of biocompatible magnetic maltose/MIL-88 metal-organic frameworks decorated with folic acid-chitosan for targeted and pH-responsive controlled release of doxorubicin

Recently, metal-organic frameworks (MOFs) have attracted tremendous attention as promising porous drug delivery systems for cancer treatment. In this work, for the first time, a novel magnetic maltose disaccharide molecule modified with MIL-88 metal-organic framework (Fe₃O₄@C@MIL-88) was prepared, and then this targeted system was used for the delivery of the doxorubicin (DOX) drug. Eventually, Fe₃O₄@C@MIL-88-DOX were successfully decorated with folic acid conjugated chitosan (Fe₃O₄@C@MIL-88-DOX-FC) as a new targeted and controlled release drug system for treatment of MCF-7 breast cancer. The encapsulation efficiency of the DOX in the Fe₃O₄@C@MIL-88 was obtained at ∼83.6%. The in vitro drug release profiles showed a pH-responsive controlled release of DOX in acidic pH confirming the performance of the systems in the cancerous environment. The DOX release mechanism from systems at pH 5 also showed that the kinetic data well fitted to the Korsmeyer-Peppas and Fickian diffusion. Furthermore, in vitro cytotoxicity and DAPI staining study clearly illustrated that the synthesized Fe₃O₄@C@MIL-88 system had low cytotoxicity and good biocompatibility against MCF-7 cancer cells and MCF-10A normal cells. Whereas, Fe₃O₄@C@MIL-88-DOX and Fe₃O₄@C@MIL-88-DOX-FC exhibited good antitumor activity as a result of targeted delivery of DOX, which indicated the MCF-7 cell death with apoptotic effects. Based on these findings, the resulting carriers could be used as promising targeted drug delivery systems for cancer therapy.

Fabrication and properties of multi-functional polydopamine coated Cu/F-codoped hydroxyapatite hollow microspheres as drug carriers

Due to its excellent bone conductivity and drug adsorption as well as pH-responsive drug release property, hydroxyapatite (HAp) is widely used as a drug carrier in bone repair field. Here, we report for the first time a novel multi-functional polydopamine (PDA) coated Cu/F-codoped HAp (Cu/F-HAp-PDA) hollow microspheres. Both Cu²⁺ and F^- were successfully doped into the lattice of HAp and uniformly distributed in the shell of hollow microspheres through a one-step hydrothermal synthesis. Then PDA was coated homogeneously on the outer layer of Cu/F-HAp hollow microspheres. Both Cu/F-HAp and Cu/F-HAp-PDA samples displayed high drug loading efficiency and pH responsive drug release behavior. Moreover, the obtained Cu/F-HAp-PDA hollow microspheres exhibited excellent photothermal conversion efficiency and photothermal stability. The molecular dynamics simulations showed that PDA and HAp can form mutual binding mainly through Ca-O bonding, while doxorubicin (DOX) is mainly bound to PDA molecules through hydrogen bonding and π-π stacking interaction.

Highly improved pH-Responsive anticancer drug delivery and T2-Weighted MRI imaging by magnetic MOF CuBTC-based nano/microcomposite

Cu-BTC framework has received a considerable attention in recent years as a drug carrier candidate for cancer treatment due to its unique structural properties and promising biocompatibility. However, its intrinsic deficiency for medical imaging potentially limits its bioapplications; To address this subject, a magnetic nano/microscale MOF has been successfully fabricated by introducing Fe₃O₄ nanoparticles as an imaging agent into the porous isoreticular MOF [Cu₃(BTC)₂] as a drug carrier. The synthesized magnetic MOFs exhibits a high loading capacity (40.5%) toward the model anticancer DOX with an excellent pH-responsive drug release. The proposed nanocomposite not only possesses large surface area, high magnetic response, large mesopore volume, high transverse relaxivity (r ²) and good stability but also exhibits superior biocompatibility, specific tumor cellular uptake, and significant cancer cell viability inhibitory effect without any targeting agent. It is expected that the synthesized magnetic nano/microcomposite may be used for clinical purposes and can also serve as a platform for photoactive antibacterial therapy ae well as pH/GSH/photo-triple-responsive nanocarrier.

Recent Advances in Metal-Organic-Framework-Based Nanocarriers for Controllable Drug Delivery and Release

Metal-organic frameworks (MOFs) have a good designability, a well-defined pore, stimulus responsiveness, a high surface area, and a controllable morphology. Up to now, various MOFs have been widely used as nanocarriers and have attracted lots of attention in the field of drug delivery and release because of their good biocompatibility and high-drug-loading capacity. Herein, we provide a comprehensive summary of MOF-based nanocarriers for drug delivery and release over the last five years. Meanwhile, some representative examples are highlighted in detail according to four categories, including the University of Oslo MOFs, Fe-MOFs, cyclodextrin MOFs, and other MOFs. Moreover, the opportunities and challenges of MOF-based smart delivery vehicles are discussed. We hope that this review will be helpful for researchers to understand the recent developments and challenges of MOF-based drug-delivery systems.

Adsorptive removal of tetracycline and ciprofloxacin drugs from water by using a magnetic rod-like hydroxyapatite and MIL-101(Fe) metal-organic framework nanocomposite

A novel porous nanocomposite composed of hydroxyapatite nanorods (HAP), a MIL-101(Fe) metal-organic framework, and Fe₃O₄ nanoparticles was successfully fabricated in this work. The magnetic HAP/MIL-101(Fe)/Fe₃O₄ ternary nanocomposite was identified by various techniques, namely FT-IR spectroscopy, XRD, Raman spectroscopy, SEM, EDX, TEM, BET specific surface area, zeta potential, and VSM measurements. Tetracycline (TC) and ciprofloxacin (CIP) aqueous solutions were used to evaluate the adsorption performance of the resulting HAP/MIL-101(Fe)/Fe₃O₄ composite. The adsorption rate and capacity of HAP/MIL-101(Fe)/Fe₃O₄ were increased as compared with HAP, MIL-101(Fe), and HAP/MIL-101(Fe) samples due to the increased attraction. The influence of initial drug concentration, adsorbent dosage, temperature, and pH on the adsorption process was investigated. The results showed that the removal efficiencies of HAP/MIL-101(Fe)/Fe₃O₄ for TC and CIP were 95% and 93%, under the determined optimum conditions: pH of 7, drug concentration of 50 mg L^-1, adsorbent dosage of 30 mg, and temperature of 25 °C. The maximum adsorption capacities of HAP/MIL-101(Fe)/Fe₃O₄ for TC and CIP were 120.48 mg g^-1 and 112.35 mg g^-1, respectively. Reusability of the prepared nanocomposite was easily achieved up to three times without significant change in its structure. As a result, the synthesized magnetic nanocomposite can be reused as a suitable absorbent for TC and CIP removal from aqueous solutions.

Tumor microenvironment targeting and regulating iron-based metal-organic framework for magnetic resonance imaging guided synergetic therapy of doxorubicin and hydroxyl radicals

Fe³⁺and 2-methylimidazole were selected to prepare tumor microenvironment targeted and regulated multifunctional drug carrier Fe-MOFs. The fact that Doxorubicin hydrochloride (DOX·HCl) release climbed 70% from 25% upon regulating the pH from 7.4 to 5.8 proved the pH responsive drug release of Fe-MOFs. Hydroxyl radicals (·OH) analysis proved that Fe-MOFs only generated hydroxyl radicals at pH 5.8, and dissolved oxygen performance showed the O₂was produced during the process, which was expected to regulate hypoxia in tumor cells to increase anticancer effect. Cell viability experiments proved the selectivity of Fe-MOFs and the excellent performance of synergy therapy of DOX·HCl and hydroxyl radicals.In vivomagnetic resonance imaging experiments demonstrated excellent performance of positive images. All experiments showed that Fe-MOFs can be used for image-guided collaborative treatment to improve treatment efficiency and reduce side effects.

Multifunctional ZnO:Gd@ZIF-8 hybrid nanocomposites with tunable luminescent-magnetic performance for potential bioapplication

Novel multifunctional ZnO:Gd@ZIF-8 hybrid inorganic-organic nanocomposites with tunable luminescent-magnetic performance were successfully fabricated using wet chemistry synthesis routes. Physico-chemical characterization including crystal structure, phase compositions, morphology, surface properties, as well as photoluminescent and magnetic characteristics was performed using powder X-ray diffraction (XRD), FT-IR analysis, transmission and scanning electron microscopies (TEM/SEM), N₂ adsorption/desorption, SQUID magnetometer, and photoluminescence spectroscopy. The biological studies of obtained materials, such as cytotoxicity profile and in vitro MRI imaging also investigated for potential use as contrast agents. Results showed that the doping with Gd³⁺ in a broad concentration range and the presence of ZIF-8 layer on ZnO affect the physico-chemical properties of the obtained composites. The obtained porous ZnO:Gd@ZIF-8 composites were highly crystalline with a large surface area. The XRD study indicated the formation of hexagonal wurtzite structure for ZnO and ZnO:Gd³⁺ (1-5 at.%). Luminescent studies showed, that ZnO is an ideal matrix for the incorporation of Gd³⁺ ions in a broad concentration range with efficient green luminescence. The PL intensity reached the maximum up to 5 at.% of Gd³⁺. The zeta potential values indicated the good stability of obtained nanoparticles. Proposed new materials with paramagnetic behavior and outstanding MR imaging capability could be used as potential contrast agents for magnetic resonance imaging.

Hydrogen-bond super-amphiphile based drug delivery system: design, synthesis, and biological evaluation

Drug delivery systems (DDSs) show great application prospects in tumor therapy. So far, physical encapsulation and covalent grafting were the two most common strategies for the construction of DDSs. However, physical encapsulation-based DDSs usually suffered from low drug loading capacity and poor stability, and covalent grafting-based DDSs might reduce the activity of original drug, which greatly limited their clinical application. Therefore, it is of great research value to design a new DDS with high drug loading capacity, robust stability, and original drug activity. Herein, we report a super-amphiphile based drug delivery system (HBS-DDS) through self-assembly induced by hydrogen bonds between amino-substituted N-heterocycles of the 1,3,5-triazines and hydrophilic carmofur (HCFU). The resulting HBS-DDS had a high drug loading capacity (38.1%) and robust stability. In addition, the drug delivery system exhibited pH-triggered size change and release of drugs because of the pH responsiveness of hydrogen bonds. In particular, the anticancer ability test showed that the HBS-DDS could be efficiently ingested by tumor cells, and its half-maximal inhibitory concentration (IC50 = 3.53 μg mL-1) for HeLa cells was close to that of free HCFU (IC50 = 5.54 μg mL-1). The hydrogen bond-based DDS represents a potential drug delivery system in tumor therapy.

Metal-Organic Frameworks and Their Composites Towards Biomedical Applications

Owing to their unique features, including high cargo loading, biodegradability, and tailorability, metal–organic frameworks (MOFs) and their composites have attracted increasing attention in various fields. In this review, application strategies of MOFs and their composites in nanomedicine with emphasis on their functions are presented, from drug delivery, therapeutic agents for different diseases, and imaging contrast agents to sensor nanoreactors. Applications of MOF derivatives in nanomedicine are also introduced. Besides, we summarize different functionalities related to MOFs, which include targeting strategy, biomimetic modification, responsive moieties, and other functional decorations. Finally, challenges and prospects are highlighted about MOFs in future applications.

Thermo/glutathione-sensitive release kinetics of heterogeneous magnetic micro-organogel prepared by sono-catalysis

To improve the loading and delivery for hydrophobic drugs and optimize the release efficiency in tumor microenvironment, a novel core-shell magnetic micro-organogel carrier was successfully prepared by a sono-catalysis process in the study. As-synthesized magnetic micro-organogel had an appropriate dispersibility in water owing to the hydrophilicity of protein shell and could be kept steadily with a well-defined spherical morphology owing to the three-dimensional gel structure of oil core, and it promised an accessible targeted drug delivery owing to its good magnetism-mediated motion ability. Moreover, the magnetic micro-organogel showed a high loading efficiency up to 94.22% for coumarin 6 which was dissolved into the micro-organogel as a model hydrophobic drug. More importantly, the release kinetics revealed that the magnetic micro-organogel had a thermo-sensitive and glutathione (GSH)-sensitive ability to control the drug release, and proved that its release mechanisms referred to the combination of erosion, diffusion and degradation.

Recent advances in nanosized metal organic frameworks for drug delivery and tumor therapy

Metal organic-frameworks (MOFs) are novel materials that have attracted increasing attention for applications in a wide range of research, owing to their unique advantages including their small particle size, porous framework structure and high specific surface area. Because of their adjustable size, nanoscale MOFs (nano-MOFs) can be prepared as carriers of biotherapy drugs, thus enabling biotherapeutic applications. Nano-MOFs' metal ion catalytic activity and organic group functional characteristics can be exploited in biological treatments. Furthermore, the applications of nano-MOFs can be broadened by hybridization with other materials to form composites. This review focuses on the preparation and recent advances in nano-MOFs as drug carriers, therapeutic materials and functionalized materials in drug delivery and tumor therapy based on the single/multiple stimulus response of drug release to achieve the targeted therapy, offering a comprehensive reference for drug carrier design. At the end, the current challenges and prospects are discussed to provide significant insight into the design and applications of nano-MOFs in drug delivery and tumor therapy.

Smart metal organic frameworks: focus on cancer treatment

Metal–organic frameworks (MOFs), as a prominent category of hybrid porous materials, have been broadly employed as controlled systems of drug delivery due to their inherent interesting properties.

Metal-Organic Framework (MOF)-Based Drug Delivery

Background:

Developing a controllable drug delivery system is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs) an emerging class of hybrid porous materials built from metal ions or clusters bridged by organic linkers have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for vast applications. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems.

Objective:

This review highlights the latest advances in the synthesis, functionalization, and applications of MOFs in drug delivery, and has classified them using drug loading strategies. Finally, challenges and future perspectives in this research area are also outlined.

In Situ Biomimetic Mineralization on ZIF-8 for Smart Drug Delivery

The exploration of metal-organic frameworks (MOFs) with good biocompatibility and physiological stability as carrier platforms for biomedical applications is of great importance but remains challenging. Herein, we developed an in situ biomimetic mineralization strategy on zeolitic imidazolate framework (ZIF) nanocrystals to construct a drug release system with favorable cytocompatibility, improved stability, and pH responsiveness. With lysozyme (Lys) wrapped on the surface of Zn-based ZIF (ZIF-8), Lys/ZIF-8 could strongly bond metal ions to promote nucleation and growth of bone-like hydroxyapatite (HAp), leading to formation of HAp@Lys/ZIF-8 composites. In vitro investigations indicate that the composites with a hollow Lys/ZIF-8 core and a HAp shell exhibited a high drug-loading efficiency (56.5%), smart pH-responsive drug delivery, cytocompatibility, and stability under physiological conditions. The proposed biomimetic mineralization strategy for designing MOFs-based composites may open a new avenue to construct advanced delivery systems in the biomedical field.

Metal-Organic Framework Composites for Theragnostics and Drug Delivery Applications

Among a plethora of nano-sized therapeutics, metal-organic frameworks (MOFs) have been some of the most investigated novel materials for, predominantly, cancer drug delivery applications. Due to their large drug uptake capacities and slow-release mechanisms, MOFs are desirable drug delivery vehicles that protect and transport sensitive drug molecules to target sites. The inclusion of other guest materials into MOFs to make MOF-composite materials has added further functionality, from externally triggered drug release to improved pharmacokinetics and diagnostic aids. MOF-composites are synthetically versatile and can include examples such as magnetic nanoparticles in MOFs for MRI image contrast and polymer coatings that improve the blood-circulation time. From synthesis to applications, this review will consider the main developments in MOF-composite chemistry for biomedical applications and demonstrate the potential of these novel agents in nanomedicine. It is concluded that, although vast synthetic progress has been made in the field, it requires now to develop more biomedical expertise with a focus on rational model selection, a major comparative toxicity study, and advanced targeting techniques.

Ultrasonic-assisted fabrication and release kinetics of two model redox-responsive magnetic microcapsules for hydrophobic drug delivery

The smart biocompatible carriers have an advantage in the high-efficiency delivery and stimuli-responsive release of drugs. This study describes two model magnetic microcapsules (MMC) fabricated by sonicating the hydrophobic drug-loaded oil phase in an albumin aqueous solution, where magnetic nanoparticles are either encapsulated into the core or embedded onto the albumin shell. The as-prepared MMC with magnetic shell (MS) or with magnetic core (MC) shows an appropriate dispersibility with a well-defined spherical morphology in water, an excellent magnetism-mediated shifting ability for targeted drug delivery, and a good biocompatibility for high-level cell viability. Moreover, both the two microcapsules also show a high efficiency to trap the hydrophobic drugs, where the embedding ratios are 87.41% for MMC-MS and 95.31% for MMC-MC, respectively. Meanwhile in current study, the release kinetics and mechanism reveal that the sulfhydryl-crosslinked shell structure endows the MMC with a redox-responsive behavior to release the contents for controlled drug release, and the release rate or the release amount can be adjusted by changing the dosage of reducing agent. Therefore, the MMC have great potential as a smart carrier of hydrophobic drugs for enhancing the therapeutic efficiency.

Solvent-Free Synthesis of CuO/HKUST-1 Composite and Its Photocatalytic Application

A metal-organic framework (MOF) is one kind of crystalline microporous material and is increasingly used as a host of catalytically active guests. Nanostructured materials supported on MOFs have presented enhanced catalytic activity and stability. Templates or several steps are essential to the synthesis of MOF composites. Simple and effective MOF synthesis methods are still challenging. Nanosized copper oxide particles in MOF composites, described as nanosized CuO@HKUST-1, were prepared by a facile solvent-free reaction. These series of CuO@HKUST-1 composites exhibited excellent photocatalytic activity for production of hydrogen and methylene blue (MB) degradation under visible light. This synthesis method provides an effective way to fabricate MOF-related nanocomposite catalysts.

An integrated targeting drug delivery system based on the hybridization of graphdiyne and MOFs for visualized cancer therapy

Multimodal therapies have been regarded as promising strategies for cancer treatment as compared to conventional drug delivery systems that have various drawbacks in either low loading content, uncontrolled release, non-targeting or biotoxicity. We have developed a multifunctional three-dimensional tumor-targeting drug delivery system, Fe3O4@UIO-66-NH2/graphdiyne (FUGY), based on the hybridization of a novel two-dimensional material, graphdiyne (GDY), with a metal organic framework (MOFs) structure, Fe3O4@UIO-66-NH2 (FU). The FU MOF structure has superior ability for magnetic targeting, and was constructed by an in situ growth method in which it was surface-installed with GDY via amide bonds, as a carrier of anticancer drugs. The anticancer drug doxorubicin (DOX) was loaded onto FUGY and served as both an anticancer drug to treat the tumor and a fluorescence probe to ascertain the location of FUGY. The results show that FUGY exhibits a high drug loading content of 43.8% and an effective drug release around the tumor cells at pH 5.0. In particular, fluorescence imaging demonstrates that FUGY can deliver more anticancer drugs to tumor tissue than conventional drug delivery systems. Furthermore, FUGY exhibits superior therapeutic efficiencies with negligible side effects as compared to the direct administration of free DOX, both in vitro and in vivo. The obtained FUGY drug delivery system possesses ideal biocompatibility, sustained drug release, effective chemotherapeutic efficacy, and specific targeting abilities. Such a multimodal therapeutic system can facilitate new possibilities for multifunctional drug delivery systems.

Hydrogen Peroxide Responsive Iron-Based Nanoplatform for Multimodal Imaging-Guided Cancer Therapy

Cancer multimodal phototherapy triggered by hydrogen peroxide has attracted widespread attention as a dominating strategy to increase phototherapeutic efficiency. Herein, a hydrogen peroxide responsive iron oxide nanoplatform, with the diameter of about 50 nm, is fabricated to intracellularly trigger the Fenton reaction and achieve synergistic photodynamic therapy and photothermal therapy. The nanoplatform based on iron oxide nanoparticles is decorated with indocyanine green (ICG, photosensitizer) and hyaluronic acid (HA, targeting molecular) through electrostatic interaction, thus the as-prepared nanoplatform (IONPs-ICG-HA) exhibits excellent active targeting ability and biocompatibility. More importantly, it can effectively utilize the intratumoral overproduced hydrogen peroxide to generate reactive oxygen species for cancer cell killing via intracellular Fenton reactions. In vitro and in vivo experiments reveal that the IONPs-ICG-HA nanocomposites realize effective photoacoustic/photothermal/fluorescence imaging-guided phototherapy, leading to promising hydrogen peroxide responsive cancer theranostics.

Effective adsorption of Congo red by a MOF-based magnetic material

A highly water-stable MOF-based magnetic material Fe₃O₄@ZTB-1 has been obtained, and it exhibited an excellent adsorption capacity for Congo red. The electrostatic interactions and hydrogen bond are responsible for binding of CR with Fe₃O₄@ZTB-1.

One-pot sustainable synthesis of magnetic MIL-100(Fe) with novel Fe3O4 morphology and its application in heterogeneous degradation

A novel, rapid and simple method is described for the synthesis of magnetic MIL-100(Fe) with novel Fe₃O₄ morphology, which significantly improved the sustainability of conventional fabrication processes in several aspects. The magnetic MOFs were prepared (i) in one pot (instead of multiple steps), (ii) at room temperature (instead of temperatures over 150 °C), (iii) within a few hours with excellent yield (instead of in few days with low productivity) and (iv) in the absence of any corrosive inorganic acid and organic reagent. The materials were tested in the industrially demanded photocatalytic and photo-Fenton degradation of sodium sulfadiazine. The degradation results indicated that the Fe₃O₄ nanorods could accelerate the catalytic efficiency. The catalyst would be of potential application due to its stable catalytic activity in repeated reaction cycles and no need for regeneration. Therefore, the MIL-100(Fe) and magnetic MIL-100(Fe) proposed in this study are ideal catalysts for the heterogeneous degradation of sodium sulfadiazine.