One-Step Synthesis of Nanoscale Zeolitic Imidazolate Frameworks with High Curcumin Loading for Treatment of Cervical Cancer

Ammonia-Responsive Colorimetric Film of Phytochemical Formulation (Alizarin) Grafted onto ZIF-8 Carrier with Poly(vinyl alcohol) and Sodium Alginate for Beef Freshness Monitoring

In this study, we devised a photothermally stable phytochemical dye by leveraging alizarin in conjunction with the metal-organic framework ZIF-8 (AL@ZIF-8). The approach involved grafting alizarin into the microporous structure of ZIF-8 through physical adsorption and hydrogen-bonding interactions. AL@ZIF-8 significantly enhanced the photostability and thermostability of alizarin. The nanoparticles demonstrate substantial color changes in various pH environments, showcasing their potential for meat freshness monitoring. Furthermore, we introduced an intelligent film utilizing poly(vinyl alcohol)-sodium alginate-AL@ZIF-8 (PA-SA-ZA) for detecting beef freshness. The sensor exhibited a superior water contact angle (52.34°) compared to the alizarin indicator. The color stability of the film was significantly enhanced under visible and UV light (ΔE < 5). During beef storage, the film displayed significant color fluctuations correlating with TVB-N (R2=0.9067), providing precise early warning signals for assessing beef freshness.

Current development of theragnostic nanoparticles for women's cancer treatment

In the biomedical industry, nanoparticles (NPs-exclusively small particles with size ranging from 1-100 nanometres) are recently employed as powerful tools due to their huge potential in sophisticated and enhanced cancer theragnostic (i.e. therapeutics and diagnostics). Cancer is a life-threatening disease caused by carcinogenic agents and mutation in cells, leading to uncontrolled cell growth and harming the body's normal functioning while affecting several factors like low levels of reactive oxygen species, hyperactive antiapoptotic mRNA expression, reduced proapoptotic mRNA expression, damaged DNA repair, and so on. NPs are extensively used in early cancer diagnosis and are functionalized to target receptors overexpressing cancer cells for effective cancer treatment. This review focuses explicitly on how NPs alone and combined with imaging techniques and advanced treatment techniques have been researched against 'women's cancer' such as breast, ovarian, and cervical cancer which are substantially occurring in women. NPs, in combination with numerous imaging techniques (like PET, SPECT, MRI, etc) have been widely explored for cancer imaging and understanding tumor characteristics. Moreover, NPs in combination with various advanced cancer therapeutics (like magnetic hyperthermia, pH responsiveness, photothermal therapy, etc), have been stated to be more targeted and effective therapeutic strategies with negligible side effects. Furthermore, this review will further help to improve treatment outcomes and patient quality of life based on the theragnostic application-based studies of NPs in women's cancer treatment.

Recent advances in metal-organic frameworks for stimuli-responsive drug delivery

After entering the human body, drugs for treating diseases, which are prone to delivery and release in an uncontrolled manner, are affected by various factors. Based on this, many researchers utilize various microenvironmental changes encountered during drug delivery to trigger drug release and have proposed stimuli-responsive drug delivery systems. In recent years, metal-organic frameworks (MOFs) have become promising stimuli-responsive agents to release the loaded therapeutic agents at the target site to achieve more precise drug delivery due to their high drug loading, excellent biocompatibility, and high stimuli-responsiveness. The MOF-based stimuli-responsive systems can respond to various stimuli under pathological conditions at the site of the lesion, releasing the loaded therapeutic agent in a controlled manner, and improving the accuracy and safety of drug delivery. Due to the changes in different physical and chemical factors in the pathological process of diseases, the construction of stimuli-responsive systems based on MOFs has become a new direction in drug delivery and controlled release. Based on the background of the rapidly increasing attention to MOFs applied in drug delivery, we aim to review various MOF-based stimuli-responsive drug delivery systems and their response mechanisms to various stimuli. In addition, the current challenges and future perspectives of MOF-based stimuli-responsive drug delivery systems are also discussed in this review.

Dual-Targeted Metal Ion Network Hydrogel Scaffold for Promoting the Integrated Repair of Tendon-Bone Interfaces

The tendon-bone interface has a complex gradient structure vital for stress transmission and pressure buffering during movement. However, injury to the gradient tissue, especially the tendon and cartilage components, often hinders the complete restoration of the original structure. Here, a metal ion network hydrogel scaffold, with the capability of targeting multitissue, was constructed through the photopolymerization of the LHERHLNNN peptide-modified zeolitic imidazolate framework-8 (LZIF-8) and the WYRGRL peptide-modified magnesium metal-organic framework (WMg-MOF) within the hydrogel scaffold, which could facilitate the directional migration of metal ions to form a dynamic gradient, thereby achieving integrated regeneration of gradient tissues. LZIF-8 selectively migrated to the tendon, releasing zinc ions to enhance collagen secretion and promoting tendon repair. Simultaneously, WMg-MOF migrated to cartilage, releasing magnesium ions to induce cell differentiation and facilitating cartilage regeneration. Infrared spectroscopy confirmed successful peptide modification of nano ZIF-8 and Mg-MOF. Fluorescence imaging validated that LZIF-8/WMg-MOF had a longer retention, indirectly confirming their successful targeting of the tendon-bone interface. In summary, this dual-targeted metal ion network hydrogel scaffold has the potential to facilitate synchronized multitissue regeneration at the compromised tendon-bone interface, offering favorable prospects for its application in the integrated reconstruction characterized by the gradient structure.

Effects of Fluorinated Functionalization of Linker on Quercetin Encapsulation, Release and Hela Cell Cytotoxicity of Cu-Based MOFs as Smart pH-Stimuli Nanocarriers

Controlled delivery of target molecules is required in many medical and chemical applications. For such purposes, metal-organic frameworks (MOFs), which possess desirable features such as high porosity, large surface area, and adjustable functionalities, hold great potential as drug carriers. Herein, Quercetin (QU), as an anticancer drug, was loaded on Cu2 (BDC)2 (DABCO) and Cu2 (F4 BDC)2 )DABCO) MOFs (BDC=1,4-benzenedicarboxylate and DABCO=1,4-diazabicyclo[2.2.2]octane). As these Cu-MOFs have a high surface area, an appropriate pore size, and biocompatible ingredients, they can be utilized to deliver QU. The loading efficiency of QU in these MOFs was 49.5 % and 41.3 %, respectively. The drug-loaded compounds displayed sustained drug release over 15 days, remarkably high drug loading capacities and pH-controlled release behavior. The prepared nanostructures were characterized by different characterization technics including FT-IR, PXRD, ZP, TEM, FE-SEM, UV-vis, and BET. In addition, MTT assays were carried out on the HEK-293 and HeLa cell lines to investigate cytotoxicity. Cellular apoptosis analysis was performed to investigate the cell death mechanisms. Grand Canonical Monte Carlo simulations were conducted to analyze the interactions between MOFs and QU. Moreover, the stability of MOFs was also investigated during and after the drug release process. Ultimately, kinetic models of drug release were evaluated.

Acute toxicity of nanoscale zeolitic imidazolate framework 8 (ZIF-8) to saltwater planktonic species Artemia salina and Nannochloropsis oculata

Zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs) are metal-organic frameworks (MOFs) that have gained significant attention in various fields due to their unique properties. They have potential applications in drug delivery, gas storage, and catalysis. However, their increasing use raises concerns about their potential environmental impact. Our study evaluates the effects of ≈90 nm ZIF-8 NPs in two planktonic species, the green microalga Nannochloropsis oculata and the brine shrimp Artemia salina. After synthesis and characterization (SEM, EDS, BET, and DLS) of nanoporous ZIF-8 NPs, a growth inhibition test on microalgae (72 h) and acute immobilization test on instar I and II of Artemia nauplii (48 h) were conducted following, OECD 201 and ISO/TS 20787, respectively. The toxicity of ZIF-8 NPs to both species was time- and concentration-dependent. The 72-h median inhibitory concentration (IC50) of ZIF-8 NPs for N. oculata based on average specific growth rate and yield were calculated as 79.71 ± 8.55 mg L-1 and 51.73 ± 5.16 mg L-1, respectively. Also, the 48-h median effective concentration (EC50) of ZIF-8 NPs on immobilization rate of instar I and II were calculated as 175.09 ± 4.14 mg L-1 and 4.69 ± 0.34 mg L-1, respectively. Moreover, the swimming type of non-immobilized animals was affected by ZIF-8 NPs. These findings provide a good insight into the toxicity of nanoparticulate ZIF-8 to saltwater planktons and also confirm that instar II Artemia is more sensitive than instar I. This study demonstrated that ZIF-8 NPs, despite all their advantages, could have toxic effects on aquatic organisms. More studies are required to assess their potential environmental impact and develop strategies to mitigate their toxicity.

pH-responsive resveratrol-loaded ZIF-8 nanoparticles modified with tannic acid for promoting colon cancer cell apoptosis

Resveratrol (Res) is known for its potential in treating various types of cancers, with a particular advantage of causing minimal toxic side effects. However, its clinical application is constrained by challenges such as poor bioavailability, low water solubility, and chemical instability in neutral and alkaline environments. In light of these limitations, we have developed a pH-responsive drug delivery nanoplatform, Res@ZIF-8/TA NPs, which exhibits good biocompatibility and shows promise for in vitro cancer therapy. Benefiting from the mild reaction conditions provided by zeolitic imidazolate frameworks (ZIFs), a "one-pot method" was used for drug synthesis and loading, resulting in a satisfactory loading capacity. Notably, Res@ZIF-8/TA NPs respond to acidic environments, leading to an improved drug release profile with a controlled release effect. Our cell-based experiments indicated that tannic acid (TA) modification enhances the biocompatibility of ZIFs. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT assay), Hoechst 33342/PI staining, cell scratch assay, Transwell and Reverse Transcription quantitative PCR (RT-qPCR) assays further demonstrated that Res@ZIF-8/TA NPs inhibited colon cancer cell migration and invasion, and promoted apoptosis of colon cancer cells, suggesting a therapeutic potential and demonstrating anti-cancer properties. In conclusion, the Res@ZIF-8/TA NPs pH-responsive drug delivery systems we developed may offer a promising avenue for cancer therapy. By addressing some of the challenges associated with Res-based treatments, this system could contribute to advancements in cancer therapeutics.

Adenosine Triphosphate-Activated Cascade Reactor for On-Demand Antibacterial Treatment Through Controlled Hydroxyl Radical Generation

Nanozymes have shown promise for antibacterial applications, but their effectiveness is often hindered by low catalytic performances in physiological conditions and uncontrolled production of hydroxyl radicals (·OH). To address these limitations, a comprehensive approach is presented through the development of an adenosine triphosphate (ATP)-activated cascade reactor (GGPcs). The GGPcs reactor synergistically combines the distinct properties of zeolitic imidazolate framework-8 (ZIF-8) and chitosan-integrated hydrogel microsphere. The ZIF-8 allows for the encapsulation of G-quadruplex/hemin DNAzyme to achieve ATP-responsive ·OH generation at neutral pH, while the hydrogel microsphere creates a confinement environment that facilitates glucose oxidation and provides a sufficient supply of H2 O2 . Importantly, the integrated chitosan in the hydrogel microsphere shields ZIF-8 from undesired disruption caused by gluconic acid, ensuring the responsive specificity of ZIF-8 toward ATP. By activating GGPcs with ATP secreted by bacteria, its effectiveness as an antibacterial agent is demonstrated for the on-demand treatment of bacterial infection with minimal side effects. This comprehensive approach has the potential to facilitate the design of advanced nanozyme systems and broaden their biological applications.

Food freshness monitoring using poly(vinyl alcohol) and anthocyanins doped zeolitic imidazolate framework-8 multilayer films with bacterial nanocellulose beneath as support

Multilayer intelligent freshness labels based on bacterial nanocellulose (BNC), poly(vinyl alcohol) (PVA), and anthocyanins doped zeolitic imidazolate framework-8 (A-ZIF-8) nanocrystals were developed in this study. First, optical, structural, thermal, and surface characterizations of A-ZIF-8 nanocrystals were performed, and the successful incorporation of anthocyanins into ZIF-8 nanocrystals was demonstrated. Next, A-ZIF-8 was added into PVA, and multilayer films were fabricated by spin-coating PVA/A-ZIF-8 layers onto BNC. The effect of the number of deposition cycles on the barrier, mechanical, thermal, morphological, and colorimetric properties of multilayer labels was investigated. The ammonia sensing, mechanical, and barrier properties of the films were shown to be tuned by the number of the PVA/A-ZIF-8 layers on the BNC. Among the developed films, BNC-2PVA/A-ZIF-8 films with the best colorimetric sensitivity toward volatile ammonia were used to monitor the freshness of skinless chicken breasts. The changes in the ΔE and a* values of BNC-2PVA/A-ZIF-8 film demonstrated a good correlation with the microbial and TVB-N levels in samples over 10 days of storage at 4 °C.

Biotin decorated celastrol-loaded ZIF-8 nano-drug delivery system targeted epithelial ovarian cancer therapy

Ovarian cancer (OC) stands as the second most prominent factor leading to cancer-related fatalities, characterized by a notably low five-year survival rate. The insidious onset of OC combined with its resistance to chemotherapy poses significant challenges in terms of treatment, emphasizing the utmost importance of developing innovative therapeutic agents. Despite its remarkable anti-tumor efficacy, celastrol (CEL) faces challenges regarding its clinical utilization in OC due to its restricted water solubility and notable side effects. In this study, celastrol (CEL) was encapsulated into Zeolitic imidazolate framework-8(ZIF-8) nanoparticle and grafted with biotin-conjugated polyethylene glycol (CEL@ZIF-8@PEG-BIO). Comprehensive comparisons of the physicochemical properties and anticancer activities of CEL and CEL@ZIF-8@PEG-BIO were conducted. Our findings revealed that CEL@ZIF-8@PEG-BIO exhibited favorable characteristics, including hydrodynamic diameters of 234.5 nm, excellent water solubility, high drug loading (31.60% ± 2.85), encapsulation efficiency (60.52% ± 2.79), and minimal side effects. Furthermore, CEL@ZIF-8@PEG-BIO can release chemicals in response to an acidic micro-environment, which is more likely a tumor micro-environment. In vitro, studies showed that CEL@ZIF-8@BIO inhibited cell proliferation, led to mitochondrial membrane potential (MMP) decline, and generated reactive oxygen species in OC cells. Both in vitro and in vivo experiments indicated that CEL@ZIF-8@PEG-BIO enhanced anti-tumor activity against OC via up-regulated apoptosis-promoting biomarkers and rendered cancer cell apoptosis via the P38/JNK MAPK signaling pathway. In conclusion, we have successfully developed a novel drug delivery system (CEL@ZIF-8@PEG-BIO), resulting in significant improvements in both water solubility and anti-tumor efficacy thereby providing valuable insights for future clinical drug development.

A simple one step synthesis of magnetic-optical dual functional ZIF-8 in a sodalite phase for magnetically guided targeting bioimaging and drug delivery

Functionalized metal-organic frameworks (MOFs) that integrate targeted tumor imaging and drug delivery are expected to significantly enhance the therapeutic efficacy of cancer. However, the complicated synthesis process has greatly limited their utilization in clinical application. Herein, a one-step simple method was used to construct novel multifunctional MOFs by co-loading doxorubicin (DOX) and Fe3O4 into the ZIF-8 with sodalite topology. DOX serves as a fluorescence imaging reagent and an anticancer drug and Fe3O4 is used as a magnetic resonance imaging and magnetic targeting anticancer reagent. The fabricated DOX/Fe3O4@ZIF-8 nanocomposite showed excellent fluorescence and magnetic resonance imaging performances in tumors. Moreover, DOX/Fe3O4@ZIF-8 can be accumulated in tumors via a magnetic targeting effect and tumor growth could be inhibited in vivo due to the release of DOX. Additionally, the apoptosis process of DOX/Fe3O4@ZIF-8 on HepG2 cells is well investigated. Overall, DOX/Fe3O4@ZIF-8 synthesized in simple one step can be used for simultaneous targeted bioimaging and cancer therapy.

Improved Cytotoxicity and Induced Apoptosis in HeLa Cells by Co-loading Vitamin E Succinate and Curcumin in Nano-MIL-88B-NH2

One of the strategies for improved therapeutic effects in cancer therapy is combination chemotherapy. In this study, a flexible nano-MOF (Fe-MIL-88B-NH2 ) was synthesized in a sonochemical process, then co-loaded with α-tocopheryl succinate (TOS) and curcumin (CCM). The anticancer activity of co-loaded Fe-MIL-88B-NH2 (Fe-MIL-88B-NH2 /TOS@CCM) against the HeLa cells was compared with that of the single-loaded counterpart (Fe-MIL-88B-NH2 @CCM). MTT analysis indicates improved cytotoxicity of Fe-MIL-88B-NH2 /TOS@CCM. The data from the cell apoptosis assay indicated more apoptosis in the case of the co-loaded nano-MOF. This study indicates the positive effect of the presence of TOS on enhancing the anticancer effect of Fe-MIL-88B-NH2 @CCM to prepare a more efficient drug delivery nanosystem.

Hierarchically Released Liquid Metal Nanoparticles for Mild Photothermal Therapy/Chemotherapy of Breast Cancer Bone Metastases via Remodeling Tumor Stromal Microenvironment

Currently, the treatment strategy for bone metastasis is mainly to inhibit the growth of tumor cells and the activity of osteoclasts, while ignoring the influence of the tumor stromal microenvironment (TSM) on the progression of bone metastasis. Herein, a dual-target liquid metal (LM)-based drug delivery system (DDS) with favorable photothermal performance is designed to spatially program the delivery of multiple therapeutic agents to enhance the treatment of bone metastasis through TSM remodeling. Briefly, mesoporous silicon-coated LM is integrated into zeolitic imidazolate framework-8 (ZIF-8) with both bone-seeking and tumor-targeting capacities. Curcumin (Cur), a tumor microenvironment modulator, is encapsulated into ZIF-8, and doxorubicin (DOX) is enclosed inside mesoporous silicon. Specific accumulation of the LM-based DDS in bone metastases first relieves the tumor stroma by releasing Cur in response to the acidic tumor microenvironment and then releases DOX deep into the tumor under near-infrared light irradiation. The combined strategy of the LM-based DDS and mild photothermal therapy has been shown to effectively restrain cross-talk between osteoclasts and tumor cells by inhibiting the secretion of transforming growth factor-β, degrading extracellular matrix components, and increasing infiltration of CD4+ and CD8+ T cells, which provides a promising strategy for the treatment of bone metastases.

Drug release and solubility properties of two zeolitic metal-organic frameworks influenced by their hydrophobicity/hydrophilicity

Metal-organic frameworks (MOFs) have shown significant potential for drug delivery applications. However, there remains a scarcity of comprehensive research addressing the influence of surface properties of MOFs on drug release kinetics and drug solubility. This study focuses on examining the influence of MOFs hydrophilicity and hydrophobicity on the controlled release and solubility of drugs. To achieve this, we prepared drug-loaded nanoparticles through in situ synthesis and created a drug-MOF co-amorphous system using the ball milling technique. Under neutral conditions, the hydrophilic MOF-based drug delivery system demonstrated a comparatively slower drug release profile than its hydrophobic counterpart. This observation suggests that the hydrophilic system holds promise in mitigating drug side effects by enabling improved control over drug release. The implementation of hydrophobic MOFs in co-amorphous systems yields a more pronounced effect on enhancing solubility compared to hydrophilic MOFs. This study offers valuable insights for achieving optimal drug release kinetics and solubility by delicately manipulating surface properties of MOFs.

Flexible Curcumin-Loaded Zn-MOF Hydrogel for Long-Term Drug Release and Antibacterial Activities

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

Recent Progress in Nanotechnology Improving the Therapeutic Potential of Polyphenols for Cancer

Polyphenols derived from fruits, vegetables, and plants are bioactive compounds potentially beneficial to human health. Notably, compounds such as quercetin, curcumin, epigallocatechin-3-gallate (EGCG), and resveratrol have been highlighted as antiproliferative agents for cancer. Due to their low solubility and limited bioavailability, some alternative nanotechnologies have been applied to encapsulate these compounds, aiming to improve their efficacy against cancer. In this comprehensive review, we evaluate the main nanotechnology approaches to improve the therapeutic potential of polyphenols against cancer using in vitro studies and in vivo preclinical models, highlighting recent advancements in the field. It was found that polymeric nanomaterials, lipid-based nanomaterials, inorganic nanomaterials, and carbon-based nanomaterials are the most used classes of nanocarriers for encapsulating polyphenols. These delivery systems exhibit enhanced antitumor activity and pro-apoptotic effects, particularly against breast, lung, prostate, cervical, and colorectal cancer cells, surpassing the performance of free bioactive compounds. Preclinical trials in xenograft animal models have revealed decreased tumor growth after treatment with polyphenol-loaded delivery systems. Moreover, the interaction of polyphenol co-delivery systems and polyphenol-drug delivery systems is a promising approach to increase anticancer activity and decrease chemotherapy side effects. These innovative approaches hold significant implications for the advancement of clinical cancer research.

Brine available two-dimensional nano-architectonics of fluorescent probe based on phosphate doped ZIF-L for detection of Fe3

Herein, we propose a simple and effective strategy for designing a zeolitic imidazolate frameworks (ZIFs) fluorescent probe with a two-dimensional leaf-like structure. By doping ZIF-L with phosphate, we developed a fluorescent probe for iron (Fe3+) in systems with high salinity. The fluorescence of P-ZIF-L was quenched effectively with the presence of Fe3+. The physicochemical structure, surface morphology, selectivity, stability and composition of the probe were investigated. Under optimized conditions, the fluorescent probe had a detection limit of 0.5 μM. Furthermore, the results that the probe exhibited desirable salt-tolerance and was suitable for determination of Fe3+ in brine water samples with satisfactory results.

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.

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

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

Zeolitic Imidazolate Framework-8 Triggers the Inhibition of Arginine Biosynthesis to Combat Methicillin-Resistant Staphylococcus Aureus

The self-preservation and intelligent survival abilities of methicillin-resistant Staphylococcus aureus (MRSA) result in the ineffective treatment of many antibiotics. Nano-drug delivery systems have emerged as a new strategy to overcome MRSA infection. ZIF-8 nanoparticles (ZIF-8 NPs) exhibit good antibacterial activities, while its molecular mechanisms are largely elusive. In this study, the ZIF-8 NPs are prepared using the room temperature solution reaction method. The values of minimum inhibitory concentration of ZIF-8 NPs against Escherichia coli and MRSA isolates are 25 and 12.5 µg mL^-1 , respectively. Transcriptome and metabonomic analyses reveal that ZIF-8 NPs could trigger the inhibition of arginine biosynthesis pathway and the production of ROS, which lead to dysfunctional tricarboxylic acid cycle and disruption of cell membrane integrity, eventually killing MRSA isolates. Moreover, ZIF-8 NPs show desirable treatment and repair effects on mice model of MRSA isolates wound infected-model. The results, for the first time, reveal that the inhibition of arginine biosynthesis mediates the production of ROS and energy metabolism dysfunction contributes to the antibacterial ability of ZIF-8 NPs against MRSA. This study offers a new insight into ZIF-8 NPs combating MRSA isolates.

Nanoscale MOFs in nanomedicine applications: from drug delivery to therapeutic agents

Metal-organic frameworks (MOFs) hold great promise for widespread applications in biomedicine and nanomedicine. MOFs are one of the most fascinating nanocarriers for drug delivery, benefiting from their high porosity and facile modification. Furthermore, the tailored components of MOFs can be therapeutic agents for various treatments, including drugs as organic ligands of MOFs, active metal as central metal ions of MOFs, and their combinations as carrier-free MOF-based nanodrug. In this review, the advances in delivery systems and applications as therapeutic agents for nanoscale MOF-based materials are summarized. The challenges of MOFs in clinical translation and the future directions in the field of MOFs therapy are also discussed. We hope that more researchers will focus their attention on advancing and translating MOF-based nanodrugs into pre-clinical and clinical applications.

BioMOF-Based Anti-Cancer Drug Delivery Systems

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided.

Microfluidic fabrication of anticancer peptide loaded ZIF-8 nanoparticles for the treatment of breast cancer

Anticancer peptides (ACPs) are promising antitumor drugs owning to their great cancer cell targeting and anticancer effects as well as low drug resistance. However, many of the ACPs have non-specific toxicity and can be easily degraded by the enzymes after administration. Therefore, drug delivery systems (DDSs) are required to shield these peptides from degradation and induce targeted delivery. In this paper, a high performance microfluidic device was used to fabricate the zeolitic imidazolate framework (ZIF-8) encapsulating an ACP (At3) recently developed by our group. The microfluidic device allowed for efficient and rapid mixing to generate ACP loaded nanoparticles (NPs) with controllable properties at high production rate (120 mL/min) and high encapsulation efficiency. The ZIF-8 NPs synthesised by microfluidic processing showed lower polydispersity index (PDI) than the conventional method, demonstrating an improved size uniformity. Encapsulating At3 into the ZIF-8 (At3@ZIF-8) significantly reduced the hemolytic effect and provided a pH-controlled release of At3 peptide. At3@ZIF-8 showed higher anticancer effect than the unloaded peptide at the same concentration due to the enhanced cell uptake by the ZIF-8 NPs. The NPs were able to inhibit the growth of the multicellular tumour spheroids (MCTSs) and damage the mitochondrial membrane of the MCF-7 breast cancer cells. In vivo experiments demonstrated that the At3@ZIF-8 NPs inhibited the growth of MCF-7 tumours in nude mice without changing the biochemical properties of the blood or the histopathological properties of vital organs. Therefore, the development of At3 loaded NPs provides an alternative approach in ACP delivery which can broaden the application of ACP-based cancer therapy.

Biodegradable Microneedle Array-Mediated Transdermal Delivery of Dimethyloxalylglycine-Functionalized Zeolitic Imidazolate Framework-8 Nanoparticles for Bacteria-Infected Wound Treatment

Bacteria-infected skin wounds caused by external injuries remain a serious challenge to the whole society. Wound healing dressings, with excellent antibacterial activities and potent regeneration capability, are increasingly needed clinically. Here, we reported a novel functional microneedle (MN) array comprising methacrylated hyaluronic acid (MeHA) embedded with pH-responsive functionalized zeolitic imidazolate framework-8 (ZIF-8) nanoparticles to treat bacteria-infected cutaneous wounds. Antibacterial activity was introduced into Zn-ZIF-8 to achieve sterilization through releasing Zn ions, as well as increased angiogenesis by dimethyloxalylglycine (DMOG) molecules that were distributed within its framework. Furthermore, biodegradable MeHA was chosen as a substrate material carrier to fabricate DMOG@ZIF-8 MN arrays. By such design, DMOG@ZIF-8 MN arrays would not only exhibit excellent antibacterial activity against pathogenic bacteria but also enhance angiogenesis within wound bed by upregulating the expression of HIF-1α, leading to a significant therapeutic efficiency on bacteria-infected cutaneous wound healing. Based on these results, we conclude that this new treatment strategy can provide a promising alternative for accelerating infected wound healing via effective antibacterial activity and ameliorative angiogenesis.

Combining dual-targeted liquid metal nanoparticles with autophagy activation and mild photothermal therapy to treat metastatic breast cancer and inhibit bone destruction

Although mild photothermal therapy (mild-PTT) avoids treatment bottleneck of the traditional PTT, the application of mild-PTT in deep and internal tumors is severely restricted due to thermal resistance, limited irradiation area and penetration depth. In addition, bone resorption caused by tumor colonization in distal bone tissue exacerbates tumor progression. Here, a strategy was developed for the treatment of bone metastasis and alleviation of bone resorption, which was based on liquid metal (LM) nanoparticle to resist thermal resistance induced by mild-PTT via autophagy activation. Briefly, LM and autophagy activator (Curcumin, Cur) were loaded into zeolitic imidazolate framework-8 (ZIF-8), which was then functionalized with hyaluronic acid/alendronate (CLALN). CLALN exhibited good photothermal performance, drug release ability under acidic environment, specifical recognition and aggregation at bone metastasis sites. CLALN combined with mild-PPT dramatically inhibited tumor progress by inducing the impaired autophagy and reduced the expression of programmed cell death ligand 1 (PD-L1) protein triggered by mild-PTT, resisting thermal resistance and alleviating the immunosuppression. Besides, CLALN combined with mild-PPT effectively alleviated osteolysis compared with only CLALN or mild-PPT. Our experiments demonstrated that this multi-functional LM-based nanoparticle combined with autophagy activation provided a promising therapeutic strategy for bone metastasis treatment. STATEMENT OF SIGNIFICANCE: Due to the limited light penetration, photothermal therapy (PTT) has limited inhibitory effect on tumor cells colonized in the bone. In addition, nonspecific heat diffusion of PTT may accidentally burn normal tissues and damage peripheral blood vessels, which can block the accumulation of drugs in deep tumors. Here, a multifunctional liquid metal based mild-PTT delivery system is designed to inhibit tumor growth and bone resorption by modulating the bone microenvironment and activating autophagy "on demand". It can overcome the treatment bottleneck of traditional PTT and improve the treatment effect of mild-PTT by resisting photothermal resistance and immune suppression. In addition, it also exhibits favorable heat/acid-responsive drug release performance and can specifically target tumor cells at the site of bone metastases.

Antitumor Effects of Curcumin on Cervical Cancer with the Focus on Molecular Mechanisms: An Exegesis

Cervical cancer is one of the most prevalent malignancies among females and is correlated with a significant fatality rate. Chemotherapy is the most common treatment for cervical cancer; however, it has a low success rate due to significant side effects and the incidence of chemo-resistance. Curcumin, a polyphenolic natural compound derived from turmeric, acts as an antioxidant by diffusing across cell membranes into the endoplasmic reticulum, mitochondria, and nucleus, where it performs its effects. As a result, it's been promoted as a chemo-preventive, anti-metastatic, and anti-angiogenic agent. As a consequence, the main goal of the present review was to gather research information that looked at the link between curcumin and its derivatives against cervical cancer.

Dual targeted zeolitic imidazolate framework nanoparticles for treating metastatic breast cancer and inhibiting bone destruction

Tumor bone metastasis is still difficult to cure despite the development of various treatment strategies. Drug delivery systems can improve the poor biological distribution of anticancer drugs in tumors. But only a very small number of nanoparticles can cross the physiological barrier to reach the tumor. In addition, the progression of bone metastasis is influenced by tumor cells, osteoclasts and bone matrix. To address these problems, a bone and tumor dual targeted nanocarrier was developed by utilizing NF-κB inhibitor loaded into zeolitic imidazolate framework-8 (ZIF-8) (CZ), which was then coated with hyaluronic acid/alendronate (HA/ALN). The CZ prepared by two-step method had high loading capacity, and the loading efficiency of Cur was to be 47.55 ± 4.03%. HA/ALN functionalization avoided explosive release of reagents and improved the stability of nanoparticles. The dual targeted ZIF-8 nanoparticle (CZ@HA/ALN) had a pH-triggered drug release performance, which effectively inhibited breast cancer cells growth and osteoclastogenesis in vitro. Uptake experiments showed that the conjugation of ALN with HA did not affect targeting ability of HA. Moreover, HA/ALN functionalized nanoparticles were more aggregated at bone metastasis sites than HA functionalized nanoparticles. CZ@HA/ALN could block the PD-1 immune check point, leading to Raw 264.7 cells differentiation into anti-tumor macrophage rather than osteoclast. The antitumor experiments in vivo exhibited that the dual targeted ZIF-8 nanoparticle effectively inhibited bone resorption and tumor progress, thereby improving the bone microenvironment. Therefore, this single but versatile nanoparticle provided a promising therapeutic scheme for bone metastasis treatment.

Modulation of Macrophages Using Nanoformulations with Curcumin to Treat Inflammatory Diseases: A Concise Review

Curcumin (Cur), a traditional Chinese medicine extracted from natural plant rhizomes, has become a candidate drug for the treatment of diseases due to its anti-inflammatory, anticancer, antioxidant, and antibacterial activities. However, the poor water solubility and low bioavailability of Cur limit its therapeutic effects for clinical applications. A variety of nanocarriers have been successfully developed to improve the water solubility, in vivo distribution, and pharmacokinetics of Cur, as well as to enhance the ability of Cur to polarize macrophages and relieve macrophage oxidative stress or anti-apoptosis, thus accelerating the therapeutic effects of Cur on inflammatory diseases. Herein, we review the design and development of diverse Cur nanoformulations in recent years and introduce the biomedical applications and potential therapeutic mechanisms of Cur nanoformulations in common inflammatory diseases, such as arthritis, neurodegenerative diseases, respiratory diseases, and ulcerative colitis, by regulating macrophage behaviors. Finally, the perspectives of the design and preparation of future nanocarriers aimed at efficiently exerting the biological activity of Cur are briefly discussed.

Smart Multifunctional UiO-66 Metal-Organic Framework Nanoparticles with Outstanding Drug-Loading/Release Potential for the Targeted Delivery of Quercetin

Herein, UiO-66 and its two functional analogs (with -NO₂ and -NH₂ functional groups) were synthesized, and their potential ability as pH stimulus nanocarriers of quercetin (QU), an anticancer agent, was studied. UiO-66 is a low-toxicity, biocompatible metal-organic framework with a large surface area and good stability, which can be prepared through a facile and inexpensive method. Before and after drug loading, various analyses were conducted to characterize the synthesized nanocarriers. Moreover, Monte Carlo simulations were performed to investigate their structures and interactions with quercetin. The most promising drug loading potential and prolonged drug release (over 25 days) were observed in QU@UiO-66-NO₂ with 37% drug loading content, which was the best-tested sample that exhibited a higher release rate under acidic conditions (pH = 5) than that in normal cells (pH = 7.4). This behavior is known as pH-stimulus-controlled ability. The cell treatment with free QU, UiO-66-R, and QU@UiO-66-R (R = -H, -NO₂, and -NH₂) was performed, and an MTT assay was conducted on HEK-293 and MDA-MB-231 cells for the cytotoxicity study. Additionally, the kinetic modeling of drug release was investigated on the basis of the analysis of the drug release profiles.

Ultrasound-Activated, Tumor-Specific In Situ Synthesis of a Chemotherapeutic Agent Using ZIF-8 Nanoreactors for Precision Cancer Therapy

The in situ transformation of low-toxicity precursors into a chemotherapeutic agent at a tumor site to enhance the efficacy of its treatment has long been an elusive goal. In this work, a zinc-based zeolitic imidazolate framework that incorporates pharmaceutically acceptable precursors is prepared as a nanoreactor (NR) system for the localized synthesis of an antitumor drug. The as-prepared NRs are administered intratumorally in a tumor-bearing mouse model and then irradiated with ultrasound (US) to activate the chemical synthesis. The US promotes the penetration of the administered NRs into the tumor tissue to cover the lesion entirely, although some NRs leak into the surrounding normal tissue. Nevertheless, only the tumor tissue, where the H₂O₂ concentration is high, is adequately exposed to the as-synthesized antitumor drug, which markedly impedes development of the tumor. No significant chemical synthesis is detected in the surrounding normal tissue, where the local H₂O₂ concentration is negligible and the US irradiation is not directly applied. The as-proposed tumor-specific in situ synthesis of therapeutic molecules induces hardly any significant in vivo toxicity and, thus, is potentially a potent biocompatible approach to precision chemotherapy.

The uptake of metal-organic frameworks: a journey into the cell

The application of metal-organic frameworks (MOFs) in drug delivery has advanced rapidly over the past decade, showing huge progress in the development of novel systems. Although a large number of versatile MOFs that can carry and release multiple compounds have been designed and tested, one of the main limitations to their translation to the clinic is the limited biological understanding of their interaction with cells and the way they penetrate them. This is a crucial aspect of drug delivery, as MOFs need to be able not only to enter into cells but also to release their cargo in the correct intracellular location. While small molecules can enter cells by passive diffusion, nanoparticles (NPs) usually require an energy-dependent process known as endocytosis. Importantly, the fate of NPs after being taken up by cells is dependent on the endocytic pathways they enter through. However, no general guidelines for MOF particle internalization have been established due to the inherent complexity of endocytosis as a mechanism, with several factors affecting cellular uptake, namely NP size and surface chemistry. In this review, we cover recent advances regarding the understanding of the mechanisms of uptake of nano-sized MOFs (nanoMOFs)s, their journey inside the cell, and the importance of biological context in their final fate. We examine critically the impact of MOF physicochemical properties on intracellular trafficking and successful cargo delivery. Finally, we highlight key unanswered questions on the topic and discuss the future of the field and the next steps for nanoMOFs as drug delivery systems.

Stem Cell Membrane-Encapsulated Zeolitic Imidazolate Framework-8: A Targeted Nano-Platform for Osteogenic Differentiation

Mesenchymal stem cells (MSCs) have been recognized as one of the most promising pharmaceutical multipotent cells, and a key step for their wide application is to safely and efficiently regulate their activities. Various methods have been proposed to regulate the directional differentiation of MSCs during tissue regeneration, such as nanoparticles and metal ions. Herein, nanoscale zeolitic imidazolate framework-8 (ZIF-8), a Zn-based metal-organic framework, is modified to direct MSCs toward an osteoblast lineage. Specifically, ZIF-8 nanoparticles are encapsulated using stem cell membranes (SCMs) to mimic natural molecules and improve the biocompatibility and targeted ability toward MSCs. SCM/ZIF-8 nanoparticles adjust the sustained release of Zn²⁺ , and promote their specific internalization toward MSCs. The internalized SCM/ZIF-8 nanoparticles show excellent biocompatibility, and increase MSCs' osteogenic potentials. Moreover, RNA-sequencing results elucidate that the activated cyclic adenosine 3,5-monophosphate (cAMP)-PKA-CREB signaling pathway can be dominant in accelerating osteogenic differentiation. In vivo, SCM/ZIF-8 nanoparticles greatly promote the formation of new bone tissue in the femoral bone defect detected by 3D micro-CT, hematoxylin and eosin staining, and Masson staining after 4 weeks. Overall, the SCM-derived ZIF-8 nanostructures achieve the superior targeting ability, biocompatibility, and enhanced osteogenesis, providing a constructive design for tissue repair.

Dissolution and Biological Assessment of Cancer-Targeting Nano-ZIF-8 in Zebrafish Embryos

Cancer-targeting nanotherapeutics offer promising opportunities for selective delivery of cytotoxic chemotherapeutics to cancer cells. However, the understanding of dissolution behavior and safety profiles of such nanotherapeutics is scarce. In this study, we report the dissolution profile of a cancer-targeting nanotherapeutic, gemcitabine (GEM) encapsulated within RGD-functionalized zeolitic imidazolate framework-8 (GEM⊂RGD@nZIF-8), in dissolution media having pH = 6.0 and 7.4. GEM⊂RGD@nZIF-8 was not only responsive in acidic media (pH = 6.0) but also able to sustain the dissolution rate (57.6%) after 48 h compared to non-targeting nanotherapeutic GEM⊂nZIF-8 (76%). This was reflected by the f₂ value of 36.1, which indicated a difference in the dissolution behaviors of GEM⊂RGD@nZIF-8 and GEM⊂nZIF-8 in acidic media compared to those in neutral media (pH = 7.4). A dissolution kinetic study showed that the GEM release mechanism from GEM⊂RGD@nZIF-8 followed the Higuchi model. In comparison to a non-targeting nanotherapeutic, the cancer-targeting nanotherapeutic exhibited an enhanced permeability rate in healthy zebrafish embryos but did not induce lethality to 50% of the embryos (LC₅₀ > 250 μg mL^-1) with significantly improved survivability (75%) after 96 h of incubation. Monitoring malformation showed minimal adverse effects with only 8.3% of edema at 62.5 μg mL^-1. This study indicates that cancer-targeting GEM⊂RGD@nZIF, with its pH-responsive behavior for sustaining chemotherapeutic dissolution in a physiologically relevant environment and its non-toxicity toward the healthy embryos within the tested concentrations, has considerable potential for use in cancer treatment.

Stability of ZIF-8 Nanoparticles in Most Common Cell Culture Media

Zeolite imidazolate framework-8 (ZIF-8) is a promising platform for drug delivery, and information regarding the stability of ZIF-8 nanoparticles in cell culture media is essential for proper interpretation of in vitro experimental results. In this work, we report a quantitative investigation of the ZIF-8 nanoparticle's stability in most common cell culture media. To this purpose, ZIF-8 nanoparticles containing sterically shielded nitroxide probes with high resistance to reduction were synthesized and studied using electron paramagnetic resonance (EPR). The degradation of ZIF-8 in cell media was monitored by tracking the cargo leakage. It was shown that nanoparticles degrade at least partially in all studied media, although the degree of cargo leakage varies widely. We found a strong correlation between the amount of escaped cargo and total concentration of amino acids in the environment. We also established the role of individual amino acids in ZIF-8 degradation. Finally, 2-methylimidazole preliminary dissolved in cell culture media partially inhibits the degradation of ZIF-8 nanoparticles. The guidelines for choosing the proper cell culture medium for the in vitro study of ZIF-8 nanoparticles have been formulated.

Improvement of curcumin loading into a nanoporous functionalized poor hydrolytic stable metal-organic framework for high anticancer activity against human gastric cancer AGS cells

Two low water-stable nanoporous Zn-based Metal-Organic Frameworks (MOFs) with and without the NO₂-functional group were synthesized by the reflux method and used to encapsulate curcumin (CCM). The characterization and application of these Zn-based MOFs (DMOF-1 and DMOF-1-NO₂) have been studied by FT-IR, PXRD,¹H NMR, N₂ adsorption, SEM, UV-vis, and fluorescence microscopy methods. The amount of drug loading of DMOF-1 and DMOF-1-NO₂ is 22.4 and 28.3 wt%, respectively. The drug loading results were also investigated by the computational simulation method. These kinds of MOFs have poor stability against water. This instability was used as a key to solving the problem of the low solubility of CCM as a model of hydrophobic cancer drug in a water-based medium. The obtained results confirmed that these poor hydrolytic MOFs could improve the solubility of CCM and enhance cytotoxicity against cancer cells (AGS) in comparison with free CCM. These results can prepare a new opportunity to increase the anticancer activity of hydrophobic drugs.

Advances and Applications of Metal-Organic Framework Nanomaterials as Oral Delivery Carriers: A Review

Oral administration is a commonly used, safe, and patient-compliant method of drug delivery. However, due to the multiple absorption barriers in the gastrointestinal tract (GIT), the oral bioavailability of many drugs is low, resulting in a limited range of applications for oral drug delivery. Nanodrug delivery systems have unique advantages in overcoming the multiple barriers to oral absorption and improving the oral bioavailability of encapsulated drugs. Metal-organic frameworks (MOFs) are composed of metal ions and organic linkers assembled by coordination chemistry. Unlike other nanomaterials, nanoscale metal-organic frameworks (nano-MOFs, NMOFs) are increasingly popular for drug delivery systems (DDSs) due to their tunable pore size and easily modified surfaces. This paper summarizes the literature on MOFs in pharmaceutics included in SCI for the past ten years. Then, the GIT structure and oral drug delivery systems are reviewed, and the advantages, challenges, and solution strategies possessed by oral drug delivery systems are discussed. Importantly, two major classes of MOFs suitable for oral drug delivery systems are summarized, and various representative MOFs as oral drug carriers are evaluated in the context of oral drug delivery systems. Finally, the challenges faced by DDSs in the development of MOFs, such as biostability, biosafety, and toxicity, are examined.

pH-responsive curcumin-based nanoscale ZIF-8 combining chemophotodynamic therapy for excellent antibacterial activity

Antimicrobial photodynamic therapy (aPDT) is a highly attractive therapy due to its advantages of being a non-antibiotic procedure for reducing drug-resistant microbes. Curcumin (CCM) has been considered as a natural photosensitizer for PDT with prominent antibacterial, antifungal, and anti-proliferative activity. However, its excellent biological and pharmacological activities are limited because of its low solubility, rapid metabolization and instability. Herein, we reported a promising agent based on CCM-incorporated into zeolitic imidazolate framework-8 (ZIF@CCM). The as-prepared nanoparticle exhibited high drug loading capability (11.57%) and drug loading encapsulation (82.76%). Additionally, ZIF@CCM displayed a pH-responsive drug release behavior and chemophotodynamic therapy for excellent antibacterial activity. The underlying mechanism elucidated that Zn²⁺ released from ZIF-8 increased the permeability of the bacterial cell membrane with leakages of K⁺. The overproduction of extracellular ROS further resulted in the disrupted bacterial cell membrane and distorted bacterial morphology. Thus, ZIF@CCM-mediated photodynamic activation might be a promising treatment strategy for microbial inactivation.

Biomimetic Metal-Organic Frameworks as Targeted Vehicles to Enhance Osteogenesis

Although engineered nanoparticles loaded with specific growth factors are used to regulate differentiation of stem cells, the low loading efficiency and biocompatibility are still great challenges in tissue repair. A nature-inspired biomimetic delivery system with targeted functions is attractive for enhancing cell activity and controlling cell fate. Herein, a stem cell membrane (SCM)-wrapped dexamethasone (DEX)-loaded zeolitic imidazolate framework-8 (ZIF-8) is constructed, which integrates the synthetic nanomaterials with native plasma membrane, to achieve efficient DEX delivery and DEX-mediated bone repair. The DEX@ZIF-8-SCM enables high DEX loading capacity, modulates the sustained release, and facilitates the specific uptake of mesenchymal stem cells (MSCs), owing to the porous property of ZIF-8 and the innate targeting capability of SCM. The endocytosed DEX@ZIF-8-SCM shows high cytocompatibility and greatly enhances the osteogenic differentiation of MSCs. Furthermore, RNA-sequencing data reveal that the phosphoinositide 3-kinase (PI3K)-Akt signaling pathways are activated and dominantly involved in the accelerated osteogenesis. In the bone defect model, the administrated DEX@ZIF-8-SCM exerts excellent biocompatibility and effectively promotes bone regeneration. Overall, the SCM-derived biomimetic nanoplatform achieves targeted delivery, excellent biosafety, and enhanced osteogenic differentiation and bone repair, which provides a new and valid strategy for treating various tissue injuries.

Hydrogen Sulfide: An Emerging Precision Strategy for Gas Therapy

Advances in nanotechnology have enabled the rapid development of stimuli-responsive therapeutic nanomaterials for precision gas therapy. Hydrogen sulfide (H₂ S) is a significant gaseous signaling molecule with intrinsic biochemical properties, which exerts its various physiological effects under both normal and pathological conditions. Various nanomaterials with H₂ S-responsive properties, as new-generation therapeutic agents, are explored to guide therapeutic behaviors in biological milieu. The cross disciplinary of H₂ S is an emerging scientific hotspot that studies the chemical properties, biological mechanisms, and therapeutic effects of H₂ S. This review summarizes the state-of-art research on H₂ S-related nanomedicines. In particular, recent advances in H₂ S therapeutics for cancer, such as H₂ S-mediated gas therapy and H₂ S-related synergistic therapies (combined with chemotherapy, photodynamic therapy, photothermal therapy, and chemodynamic therapy) are highlighted. Versatile imaging techniques for real-time monitoring H₂ S during biological diagnosis are reviewed. Finally, the biosafety issues, current challenges, and potential possibilities in the evolution of H₂ S-based therapy that facilitate clinical translation to patients are discussed.

Embedding an extraordinary amount of gemifloxacin antibiotic in ZIF-8 framework with one-step synthesis and measurement of its H2O2-sensitive release and potency against infectious bacteria

GEM@ZIF-8 has DLC = 69.82% and DLE = 89.03%, with controlled release dependent on H2O2 concentration, and it shows significant antibacterial activity.

In situ synthesis of a functional ZIF-8 nanocomposite for synergistic photodynamic–chemotherapy and pH and NIR-stimulated drug release

UCNP/TiO2/Cur@ZIF-8 can be used as a NIR and pH-responsive photodynamic-chemo candidate for tumor therapy.

Pd-Cu nanoalloy for dual stimuli-responsive chemo-photothermal therapy against pathogenic biofilm bacteria

Photothermal therapy (PTT) is a promising strategy for antimicrobial therapy. However, the application of PTT to treat bacterial infections remains a challenge as the high temperature required for bacterial elimination can partly damage healthy tissues. Selecting the appropriate treatment temperature is therefore a key factor for PTT. In this work, we designed a near-infrared/pH dual stimuli-responsive activated procedural antibacterial system based on zeolitic imidazolate framework-8 (ZIF-8), which was bottom-up synthesized and utilized to encapsulate both Pd-Cu nanoalloy (PC) and the antibiotic amoxicillin (AMO). This procedural antibacterial therapy comprises chemotherapy (CT) and PTT. The former disrupts the bacterial cell wall by releasing AMO in an acidic environment, which depends on the sensitive response of ZIF-8 to pH value change. With the progression in time, the AMO release rate decreased gradually. The latter can then significantly stimulate drug release and further complete the antibacterial effect. This impactful attack consisted of two waves that constitute the procedural therapy for bacterial infection. Accordingly, the treatment temperature required for antibacterial therapy can be significantly lowered under this mode of treatment. This antibacterial system has a significant therapeutic effect on planktonic bacteria (G⁺/G^-) and their biofilms and also has good biocompatibility; thus, it provides a promising strategy to develop an effective and safe treatment against bacterial infections. STATEMENT OF SIGNIFICANCE: We have developed a near infrared/pH dual stimuli-responsive activated procedural antibacterial system that combines enhanced antibiotic delivery with photothermal therapy and has highly efficient antimicrobial activity. The antibacterial effect of this therapy was based on two mechanisms of action: chemotherapy, in which the bacterial cell wall was first destroyed, followed by photothermal therapy. After exposure to irradiation with an 808 nm laser, the inhibition rates were 99.8% and 99.1% for Staphylococcus aureus and Pseudomonas aeruginosa, respectively, and the clearance rates for their established biofilms were 75.3% and 74.8%, respectively. Thus, this procedural antibacterial therapy has shown great potentiality for use in the photothermal therapy of bacterial infectious diseases, including biofilm elimination.