Recent development of amorphous metal coordination polymers for cancer therapy

Regulation of osteoimmune microenvironment via functional dynamic hydrogel for diabetic bone regeneration

Bone regeneration and repair face formidable challenges under diabetic conditions, primarily due to the disruption of macrophage polarization induced by diabetes and the inflammatory imbalance within the bone microenvironment. We have developed a novel dynamic hydrogel system (AG-CD@LINA), constructed through the coordination crosslinking of thiolated gelatin (SH-Gelatin) and gold ions (Au3+), followed by grafting with cyclodextrin to load the ligand linagliptin. This hydrogel effectively inhibits the formation of M1 macrophages and the expression of pro-inflammatory cytokines by gradually releasing linagliptin. Simultaneously, it promotes the formation of M2 macrophages and the expression of anti-inflammatory cytokines, thus improving the inflammatory microenvironment of diabetic bone defects. Consequently, it facilitates the migration of mesenchymal stem cells and angiogenic cells, augments osteogenic activity, and promotes vascularization, collectively accelerating the regeneration of diabetic bone tissue. Mechanistically, polarization occurs through the TLR3-NF-κB signaling pathway. In vivo experiments demonstrate that the in-situ injection of the hydrogel enhances the regeneration of bone tissue and the restoration of bone structure in diabetic bone defects, effectively modulating local inflammation and promoting vascular formation. This study suggests that functionalized dynamic hydrogels can improve the inflammatory microenvironment by regulating in situ macrophage polarization, thereby facilitating the reconstruction of bone microstructure. This approach represents a promising novel therapeutic strategy for diabetic bone defects.

Evaluation of Intermolecular Weak Binding Through the Zero-Field Splitting of an Endofullerene High-Spin Probe

Weak binding between molecules is becoming a renowned aspect of molecular engineering, offering an alternative to the tuning of conventional chemical bonds. However, the subtle nature of these interactions poses challenges for characterization using standard techniques. Herein, an efficient method of weak binding characterization based on the zero-field splitting of a high-spin probe by electron paramagnetic resonance is presented. Using endofullerene as the high spin center, we achieved direct comparison of the weak binding strengths in F-MTPP (M = H2, Zn, Ni, and Pd) and 2F-3MTPP (M = H2, Ni, Pd, and Pt) through the zero-field splitting parameters. The high-spin resonance spectrum is sensitive to the small variation in the supramolecular structure. By examining fullerene-porphyrin co-crystals with various metal centers and packing arrangements, the relation between intermolecular weak binding and microstructural strain on the fullerene cage is elucidated.

Metal coordination polymer nanoparticles for cancer therapy

Metal ions are essential elements in biological processes and immune homeostasis. They can regulate cancer cell death through multiple distinct molecular pathways and stimulate immune cells implicated in antitumor immune responses, suggesting opportunities to design novel metal ion-based cancer therapies. However, their small size and high charge density result in poor target cell uptake, uncontrolled biodistribution, and rapid clearance from the body, reducing therapeutic efficacy and increasing potential off-target toxicity. Metal coordination polymer nanoparticles (MCP NPs) are nanoscale polymer networks composed of metal ions and organic ligands linked via noncovalent coordination interactions. MCP NPs offer a promising nanoplatform for reshaping metal ions into more drug-like formulations, improving their in vivo pharmacological performance and therapeutic index for cancer therapy applications. This review provides a comprehensive overview of the inherent biological functions of metal ions in cancer therapy, showcasing examples of MCP NP systems designed for preclinical cancer therapy applications where drug delivery principles play a critical role in enhancing therapeutic outcomes. MCP NPs offer versatile metal ion engineering approaches using selected metal ions, various organic ligands, and functional payloads, enabling on-demand nano-drug designs that can significantly improve therapeutic efficacy and reduce side effects for effective cancer therapy.

High AIPH-Loaded Infinite coordination Polymers nanoparticles for long-term thermodynamic-chemo cascade tumor synergistic therapy

To enhance the tumor thermodynamic-chemo synergistic therapy efficacy, high loading of AIPH-Cu(II)-AQ4N Infinite Coordination Polymer nanoparticles (ICP NPs) were developed, which have high AIPH loading of 44.5 %, thermal stability, pH responsive release all therapeutic agents in the tumor tissue and lower toxicity. A long-term thermodynamic-chemo cascade tumor synergistic therapy strategy was developed with these nanoparticles. It is found ICP NPs exhibit diameters of 115.8 ± 23.7 nm, a substantial fraction of AQ4N and less 40 % of AIPH is released from ICP NPs within 70 h at pH 4.0-5.0, while the release rates of AQ4N and AIPH from ICP NPs over 72 h almost no release in normal tissues. A long-term two-stage therapeutic cascade procedure assisted by electrothermal was carried out, in which sufficient amount of AIPH maintain thermodynamic therapy 10 min at first stage and thermodynamic-chemo synergistic therapy 72 h at second stage. Under this procedure, the resulting nanoparticles demonstrate the powerful comprehensive therapeutic outcomes, small tumor entire eliminated and there is no recurrence for 60 days. Even for large tumors, the tumor inhibition rate is as high as 90 % at 16 days using lower drug dosage. This study offers remarkable potential for tumor cascade synergistic therapy in future.

Facile Synthesis of Fe-Based Metal-Quinone Networks for Mutually Enhanced Mild Photothermal Therapy and Ferroptosis

Mild photothermal therapy (MPTT) has emerged as a promising therapeutic modality for attenuating thermal damage to the normal tissues surrounding tumors, while the heat-induced upregulation of heat shock proteins (HSPs) greatly compromises the curative efficacy of MPTT by increasing cellular thermo-tolerance. Ferroptosis has been identified to suppress the overexpression of HSPs by the accumulation of lipid peroxides and reactive oxygen species (ROS), but is greatly restricted by overexpressed glutathione (GSH) in tumor microenvironment and undesirable ROS generation efficiency. Herein, a synergistic strategy based on the mutual enhancement of MPTT and ferroptosis is proposed for cleaving HSPs to recover tumor cell sensitivity. A facile method for fabricating a series of Fe-based metal-quinone networks (MQNs) by coordinated assembly is proposed and the representative FTP MQNs possess high photothermal conversion efficiency (69.3 %). Upon 808 nm laser irradiation, FTP MQNs not only trigger effective MPTT to induce apoptosis but more significantly, potentiate Fenton reaction and marked GSH consumption to boost ferroptosis, and the reinforced ferroptosis effect in turn can alleviate the thermal resistance by declining the HSP70 defense and reducing ATP levels. This study provides a valuable rationale for constructing a large library of MQNs for achieving mutual enhancement of MPTT and ferroptosis.

Tumor Microenvironment-Responsive Biodegradable Nanomedicine for Self-Enhanced Synergistic Chemo-, Photothermal, and Chemodynamic Therapy

The nanoscale multidrug codelivery system for synergistic therapy is an effective strategy for tumor treatment. However, the low drug delivery efficiency and poor therapeutic effects limit its application. Here, based on the coordination effect of Artemisinin (Art), quercetin (Qc), and Fe3+, we had constructed a safe and efficient carrier-free hyaluronic acid (HA)-modified Art-Fe-Qc nanoparticles (AFQ@HA NPs) for enhanced chemotherapy/photothermal therapy (PTT)-chemodynamic therapy (CDT) synergistic therapy, which achieved an ultrahigh drug loading efficiency and a multifunction anticancer strategy. The results showed that high drug loading was achieved based on drug coordination self-assembly, with Art and Qc contents of 38.6 and 42.7%, respectively. At the same time, based on the Qc-Fe coordination molecular network, the system had excellent photothermal conversion performance with an efficiency of 57.3% and could effectively inhibit the expression of HSP70, achieving enhanced PTT. Further, under the stimulation of excessive H2O2 and glutathione (GSH) in the tumor microenvironment, the AFQ@HA NPs were continuously degraded, while releasing Art and Fe3+/Fe2+ to achieve iron ion-enhanced CDT. The results of in vitro and in vivo experiments showed that AFQ@HA NPs could achieve chemotherapy-PTT-CDT synergistic therapy in response to tumor microenvironment by passively targeting and actively targeting tumor cells with CD44, demonstrating its excellent targeted antitumor effects.

Fluorescent responsive membrane based on terbium coordination polymer and carbon dots with AIE effect for rapid and visual detection of fluoroquinolone

In this study, based on aggregation-induced emission (AIE) effect and antenna effect, a novel portable fluorescent responsive membrane was constructed with red carbon dots (R-CDs) as reference signal and terbium coordination polymer (Tb-AMP CPs) as response signal for visual, instrument-free, and sensitive detection of fluoroquinolones (FQs). Specifically, the fluorescent responsive membrane (R-T membrane) was prepared by physically depositing R-CDs with AIE property and Tb-AMP CPs on the surface of polyvinylidene fluoride filter membranes at ambient temperature. In the presence of FQs, Tb3+ in the Tb-AMP CPs of the prepared membrane coordinated with the β-diketone structure of FQs, which turned on the yellow-green fluorescence through the "antenna effect". As the concentration of FQs increased, the R-T membrane achieved a fluorescent color transition from bright pink to yellow-green. Its visual detection sensitivity for three FQs, including ciprofloxacin, difloxacin, and enrofloxacin, was 0.01 μM, and the detection limits were 7.4 nM, 7.8 nM, and 9.2 nM, respectively, by analyzing the color parameter green. In the residue analysis of FQs in real samples, the constructed membrane also exhibited remarkable anti-interference and reliability, which is of great significance for ensuring the safety of animal-derived food.

Spiderweb-Shaped Iron-Coordinated Polymeric Network as the Novel Coating on Microneedles for Transdermal Drug Delivery Against Infectious Wounds

Coated microneedles (CMNs) are a minimally invasive platform for immediate-release transdermal drug delivery. However, the practical applications of CMNs have been significantly hindered by the challenges associated with complex formulations, single function, and limited drug loading capacity. This study has developed a spiderweb-shaped iron-coordinated polymeric nanowire network (Fe-IDA NWs). The resulting Fe-IDA NWs are endowed with a certain viscosity due to the synergy of multiple supramolecular interactions. This allows them to replace traditional polymeric thickeners as microneedle coatings. The Fe-IDA NWs-coated microneedles (Fe-IDA MNs) display rapid disintegration in the skin model, which also enables the swift diffusion of Fe-IDA NWs and their payloads into the deeper skin layers. Additionally, Fe-IDA MNs exhibit desirable enzymatic activity and potential antibacterial ability. Thus, Fe-IDA MNs can enhance the therapeutic efficacy against wound infection through synergistic effects, and avoid the overly complicated formulation and the release of nontherapeutic molecules of conventional CMNs. As a proof-of-concept, Fe-IDA MNs loaded with chlorin e6 showed a synergistic chemodynamic-photodynamic antibacterial effect in a methicillin-resistant Staphylococcus aureus-infected wound model in mice. Collectively, this work has significant implications for the future of CMNs-based transdermal drug delivery systems and expands the application fields of metal coordination polymer (MCP) materials.

Metal-Drug Coordination Nanoparticles and Hydrogels for Enhanced Delivery

Drug delivery is a key component of nanomedicine, and conventional delivery relies on the adsorption or encapsulation of drug molecules to a nanomaterial. Many delivery vehicles contain metal ions, such as metal-organic frameworks, metal oxides, transition metal dichalcogenides, MXene, and noble metal nanoparticles. These materials have a high metal content and pose potential long-term toxicity concerns leading to difficulties for clinical approval. In this review, recent developments are summarized in the use of drug molecules as ligands for metal coordination forming various nanomaterials and soft materials. In these cases, the drug-to-metal ratio is much higher than conventional adsorption-based strategies. The drug molecules are divided into small-molecule drugs, nucleic acids, and proteins. The formed hybrid materials mainly include nanoparticles and hydrogels, upon which targeting ligands can be grafted to improve efficacy and further decrease toxicity. The application of these materials for addressing cancer, viral infection, bacterial infection inflammatory bowel disease, and bone diseases is reviewed. In the end, some future directions are discussed from fundamental research, materials science, and medicine.

Zirconium-containing nanoscale coordination polymers for positron emission tomography and fluorescence-guided cargo delivery to triple-negative breast tumors

Nanoscale coordination polymer (NCP) is a class of hybrid materials formed by self-assembly of metal ions and organic ligands through coordination. The applications of NCP in biomedicine are quite extensive due to the diversity choice of metal ions and organic ligands. Here we designed Zr-P1 NCP based on Zr4+ selected as metal ion nodes and tetrakis(4-carboxyphenyl) ethylene as bridging ligands. Zr-P1 NCP was modified with functionalized pyrene derived polyethylene glycol (Py-PAA-PEG-Mal) on the surface and further conjugated with cRGD for active targeting of integrin αvβ3 overexpressed in triple-negative breast cancer. Doxorubicin was loaded on Zr-P1 NCP with encapsulation efficiency up to 22 % for the treatment of triple negative breast cancer. 89Zr-P1 NCP can be used for in vivo tumor imaging due to the fluorescence properties resulting from the enhanced aggregation-induced Emission (AIE) behavior of P1 ligands and its positron emission tomography (PET) capability. Cellular evaluation indicated that the functionalized Zr-P1@PEG-RGD presented a good function for tumor cell targeting imaging and doxorubicin could be targeted to triple negative breast cancer when it was loaded onto Zr-P1@PEG-RGD, which corroborated with the in vivo results. In summary, 89Zr-P1@PEG-RGD can serve as a biocompatible nanoplatform for fluorescence and PET image-guided cargo delivery. STATEMENT OF SIGNIFICANCE: Nanoscale coordination polymer (NCP) is a class of hybrid materials formed by self-assembly of metal ions and organic ligands through coordination. The diversity of available metals and ligand structures upon NCP synthesis plays an advantage in establishing multimodal imaging platforms. Here we designed 89Zr-P1@PEG-RGD NCP based on Zr4+ selected as metal ion nodes and tetrakis(4-carboxyphenyl) ethylene as bridging ligands. 89Zr-P1@PEG-RGD nanomaterials have positron emission tomography (PET) capability due to the incorporation of zirconium-89, which can be used for in vivo tumor imaging with high sensitivity. The chemotherapeutic drug DOX was loaded on Zr-P1 NCP for the treatment of triple-negative breast cancer, and dual modality imaging can provide visual guidance for drug delivery.

Metal-Coordination-Mediated H-Aggregates of Cyanine Dyes for Effective Photothermal Therapy

Integration of cyanine dyes and metal ions into one nanoplatform via metal-coordination interactions is an effective strategy to build multimodality phototheranostics. The multifunctionalities of the formed nanoscale metal-organic particles (NMOPs) have been widely explored. However, the effect of metal-coordination interaction on the aggregation behavior of cyanine dyes is rarely reported. Herein, we reported the H-aggregation behavior of cyanine dye Cy-3COOH induced by different metal ions M (Fe2+ or Mn2+ ). Moreover, the extent of H-aggregates varied with different metal-coordination interactions. Upon NIR irradiation, H-aggregates of Cy-3COOH remarkably promoted photothermal conversion efficiency. Interestingly, we also find that H-aggregates of Cy-3COOH induced by metal ions can generate the reactive oxygen species (ROS) involving singlet oxygen (1 O2 ) and superoxide anion radical (O2 - ⋅) upon light irradiation. In addition, the ROS efficiency varies depending on the extent of H-aggregates. Additionally, the photoinduced ROS could disassemble aggregates and decompose cyanine dye Cy-3COOH, which limits the photothermal capability of Cy-3COOH/M NPs. Therefore, the photothermal performance of Cy-3COOH/M NPs could be manipulated by the degree of H-aggregation. This would provide a new insight to develop efficient phototheranostics NMOPs for cancer treatment.

Curcumin-Containing Polyphosphazene Nanodrug for Anti-Inflammation and Nerve Regeneration to Improve Functional Recovery After Spinal Cord Injury

The microenvironment of excessive inflammation and the activation of apoptotic signals are primary barriers to neurological recovery following spinal cord injury (SCI). Thus, long-lasting anti-inflammation has become an effective strategy to navigate SCI. Herein, a curcumin (CUR)-containing nanosystem (FCTHPC) with high drug loading efficiency was reported via assembling hydrophobic CUR into cross-linked polyphosphazene (PPZ), and simultaneous loading and coordinating with porous bimetallic polymers for greatly enhanced the water-solubility and biocompatibility of CUR. The nanosystem is noncytotoxic when directing its biological activities. By inhibiting the expression of pro-inflammatory factors (IL-1β, TNF-α and IL-6) and apoptotic proteins (C-caspase-3 and Bax/Bcl-2), which may be accomplished by activating the Wnt/β-catenin pathway, the versatile FCTHPC can significantly alleviate the damage to tissues and cells caused by inflammation and apoptosis in the early stage of SCI. In addition, the long-term in vivo studies had demonstrated that FCTHPC could effectively inhibit the formation of glial scars, and simultaneously promote nerve regeneration and myelination, leading to significant recovery of spinal cord function. This study emphasises the promise of the biocompatible CUR-based nanosystem and provides a fresh approach to effectively treat SCI.

Stimuli-responsive nanocarrier delivery systems for Pt-based antitumor complexes: a review

Platinum-based anticancer drugs play a crucial role in the clinical treatment of various cancers. However, the application of platinum-based drugs is heavily restricted by their severe toxicity and drug resistance/cross resistance. Various drug delivery systems have been developed to overcome these limitations of platinum-based chemotherapy. Stimuli-responsive nanocarrier drug delivery systems as one of the most promising strategies attract more attention. And huge progress in stimuli-responsive nanocarrier delivery systems of platinum-based drugs has been made. In these systems, a variety of triggers including endogenous and extracorporeal stimuli have been employed. Endogenous stimuli mainly include pH-, thermo-, enzyme- and redox-responsive nanocarriers. Extracorporeal stimuli include light-, magnetic field- and ultrasound responsive nanocarriers. In this review, we present the recent advances in stimuli-responsive drug delivery systems with different nanocarriers for improving the efficacy and reducing the side effects of platinum-based anticancer drugs.

Direct synthesis of amorphous coordination polymers and metal–organic frameworks

Coordination polymers (CPs) and their subset, metal-organic frameworks (MOFs), can have porous structures and hybrid physicochemical properties that are useful for diverse applications. Although crystalline CPs and MOFs have received the most attention to date, their amorphous states are of growing interest as they can be directly synthesized under mild conditions. Directly synthesized amorphous CPs (aCPs) can be constructed from a wider range of metals and ligands than their crystalline and crystal-derived counterparts and demonstrate numerous unique material properties, such as higher mechanical robustness, increased stability and greater processability. This Review examines methods for the direct synthesis of aCPs and amorphous MOFs, as well as their properties and characterization routes, and offers a perspective on the opportunities for the widespread adoption of directly synthesized aCPs.

Research Status and Prospect of Non-Viral Vectors Based on siRNA: A Review

Gene therapy has attracted much attention because of its unique mechanism of action, non-toxicity, and good tolerance, which can kill cancer cells without damaging healthy tissues. siRNA-based gene therapy can downregulate, enhance, or correct gene expression by introducing some nucleic acid into patient tissues. Routine treatment of hemophilia requires frequent intravenous injections of missing clotting protein. The high cost of combined therapy causes most patients to lack the best treatment resources. siRNA therapy has the potential of lasting treatment and even curing diseases. Compared with traditional surgery and chemotherapy, siRNA has fewer side effects and less damage to normal cells. The available therapies for degenerative diseases can only alleviate the symptoms of patients, while siRNA therapy drugs can upregulate gene expression, modify epigenetic changes, and stop the disease. In addition, siRNA also plays an important role in cardiovascular diseases, gastrointestinal diseases, and hepatitis B. However, free siRNA is easily degraded by nuclease and has a short half-life in the blood. Research has found that siRNA can be delivered to specific cells through appropriate vector selection and design to improve the therapeutic effect. The application of viral vectors is limited because of their high immunogenicity and low capacity, while non-viral vectors are widely used because of their low immunogenicity, low production cost, and high safety. This paper reviews the common non-viral vectors in recent years and introduces their advantages and disadvantages, as well as the latest application examples.

Pillararene-Based Supramolecular Polymers for Cancer Therapy

Supramolecular polymers have attracted considerable interest due to their intriguing features and functions. The dynamic reversibility of noncovalent interactions endows supramolecular polymers with tunable physicochemical properties, self-healing, and externally stimulated responses. Among them, pillararene-based supramolecular polymers show great potential for biomedical applications due to their fascinating host-guest interactions and easy modification. Herein, we summarize the state of the art of pillararene-based supramolecular polymers for cancer therapy and illustrate its developmental trend and future perspective.

Intratumoral synthesis of transformable metal-phenolic nanoaggregates with enhanced tumor penetration and retention for photothermal immunotherapy

Rationale: Effective photothermal therapy (PTT) remains a great challenge due to the difficulties of delivering photothermal agents with both deep penetration and prolonged retention at tumor lesion spatiotemporally. Methods: Here, we report an intratumoral self-assembled nanostructured aggregate named FerH, composed of a natural polyphenol and a commercial iron supplement. FerH assemblies possess size-increasing dynamic kinetics as a pseudo-stepwise polymerization from discrete nanocomplexes to microscale aggregates. Results: The nanocomplex can penetrate deeply into solid tumors, followed by prolonged retention (> 6 days) due to the in vivo growth into nanoaggregates in the tumor microenvironment. FerH performs a targeting ablation of tumors with a high photothermal conversion efficiency (60.2%). Importantly, an enhanced immunotherapeutic effect on the distant tumor can be triggered when co-administrated with checkpoint-blockade PD-L1 antibody. Conclusions: Such a therapeutic approach by intratumoral synthesis of metal-phenolic nanoaggregates can be instructive to address the challenges associated with malignant tumors.

Application of MOF-based nanotherapeutics in light-mediated cancer diagnosis and therapy

Light-mediated nanotherapeutics have recently emerged as promising strategies to precisely control the activation of therapeutic reagents and imaging probe both in vitro and in vivo, largely ascribed to their unique properties, including minimally invasive capabilities and high spatiotemporal resolution. Nanoscale metal-organic frameworks (NMOFs), a new family of hybrid materials consisting of metal attachment sites and bridging ligands, have been explored as a new platform for enhanced cancer diagnosis and therapy due to their tunable size, modifiable surface, good biocompatibility, high agent loading and, most significantly, their ability to be preferentially deposited in tumors through enhanced permeability and retention (EPR). Especially the light-driven NMOF-based therapeutic platform, which not only allow for increased laser penetration depth and enhanced targeting, but also enable imaging-guided or combined treatments. This review provides up-to-date developments of NMOF-based therapeutic platforms for cancer treatment with emphasis on light-triggered therapeutic strategies and introduces their advances in cancer diagnosis and therapy in recent years.

Effects of polymer carriers on the occurrence and development of autophagy in drug delivery

Autophagy is an evolutionarily conserved catabolic process that can degrade cytoplasmic materials and recycle energy to maintain metabolite homeostasis in cells. Autophagy is closely related to various physiological or pathological processes. Macromolecular materials are widely used in drug delivery systems and disease treatments due to their intrinsic effects, such as altered pharmacokinetics and biodistribution. Interaction of autophagic flux or the signal pathway with macromolecules may cause autophagy inhibition or autophagy cell death. This review covers autophagy regulation pathways and macromolecular materials (including functional micelles, biodegradable and pH-sensitive polymers, biomacromolecules, dendrimers, coordination polymers, and hybrid nanoparticles) mediated autophagy modulation.

Ultrasmall Coordination Polymers for Alleviating ROS-Mediated Inflammatory and Realizing Neuroprotection against Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease globally, and there is currently no effective treatment for this condition. Excessive accumulation of reactive oxygen species (ROS) and neuroinflammation are major contributors to PD pathogenesis. Herein, ultrasmall nanoscale coordination polymers (NCPs) coordinated by ferric ions and natural product curcumin (Cur) were exploited, showing efficient neuroprotection by scavenging excessive radicals and suppressing neuroinflammation. In a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse PD model, such ultrasmall Fe-Cur NCPs with prolonged blood circulation and BBB traversing capability could effectively alleviate oxidative stress, mitochondrial dysfunction, and inflammatory condition in the midbrain and striatum to reduce PD symptoms. Thus, this study puts forth a unique type of therapeutics-based NCPs that could be used for safe and efficient treatment of PD with potential in clinical translation.

Design, preparation and pharmacodynamics of ICG-Fe(Ⅲ) based HCPT nanocrystals against cancer

The use of nanocrystal technology to manufacture drug delivery systems intended to enhance therapeutic efficacy has attracted the attention of the pharmaceutical industry. However, the clinical application of nanocrystal drugs for injection is restricted by Ostwald ripening and the large-scale use of stabilizers such as polysorbate and lecithin, which have potential toxicity risks including hemolysis and allergies. Here, we designed an amorphous nanocrystal drug complex (IHNC), which is stabilizer-free and composed of indocyanine green (ICG) framework loading with a chemotherapeutic agent of 10-hydroxycamptothecin (HCPT). Considering the possibility of industrial manufacturing, IHNC was simply prepared with the assistance of ferric ion (III) via supramolecular assembly strategy. The theoretical result of Materials Studio simulation indicated that the prepared ICG-Fe(III) framework showed a stable spherical structure with the appropriate cavity for encapsulating the two drugs of HCPT and ICG with equal mass ratio. The IHNC was stable at physiological pH, with excellent PTT/PDT efficacy, and in vivo probing characteristics. The nanoscale size and reductive stimuli-responsiveness can be conducive to drug accumulation into the tumor site and rapid unloading of cargo. Moreover, such combination therapy showed synergistic photo/chemotherapy effect against 4T1 breast cancer and its tumor inhibition rate even up to 79.4%. These findings demonstrated that the nanocrystal drug delivery strategy could avoid the use of stabilizers and provide a new strategy for drug delivery for combination therapy.

Phosphorus or Nitrogen - The first Phosphatriptycene in Coordination Polymer Chemistry

Phosphasilatriptycene, a phenylene spacer and a pyridyl moiety represent the building blocks of TRIP-Py, the first heteroditopic ligand featuring a phoshatriptycene scaffold. The P and N donor sites located at...

pH-responsive hollow Fe-gallic acid coordination polymer for multimodal synergistic-therapy and MRI of cancer

Tumor-microenvironment (TME) responsive nanostructures are attractive for drug delivery in clinical cancer treatment. The coordination polymer Fe-gallic acid (Fe-GA) is one of the promising drug carriers due to its pH-response, good biocompatibility, and minimal side effects. However, the hollow nanostructures of Fe-GA have not been reported until now, which seriously limits the quantity of drug delivery. Herein, hollow Fe-GA nanospheres were prepared for the first time with bovine serum albumin (BSA) combination (denoted as Fe-GA/BSA) under mild reaction conditions. Then, the antitumor drug doxorubicin (DOX) was loaded in the hollow Fe-GA/BSA to obtain Fe-GA/BSA@DOX. A series of experiments in vitro and in vivo indicated that the Fe-GA/BSA@DOX could efficiently respond to TME and release DOX and Fe(iii) ions. Furthermore, the Fe(iii) could consume overexpressed glutathione (GSH) in cancer cells and generate Fe(ii) to trigger the Fenton reaction, producing ·OH for chemodynamic treatment (CDT) of cancer. In addition, the Fe-GA/BSA@DOX could effectively convert near-infrared (NIR) light into heat by acting as a photothermal therapy (PTT) agent. Besides that, magnetic resonance imaging (MRI) data also showed that the Fe-GA/BSA had beneficial T1 and T2 imaging effects, demonstrating that the hollow Fe-GA/BSA has potential for multimodal synergistic cancer MRI diagnosis and therapies of drugs, CDT, and PTT.

Graphene and its derivatives: understanding the main chemical and medicinal chemistry roles for biomedical applications

Over the past few years, there has been a growing potential use of graphene and its derivatives in several biomedical areas, such as drug delivery systems, biosensors, and imaging systems, especially for having excellent optical, electronic, thermal, and mechanical properties. Therefore, nanomaterials in the graphene family have shown promising results in several areas of science. The different physicochemical properties of graphene and its derivatives guide its biocompatibility and toxicity. Hence, further studies to explain the interactions of these nanomaterials with biological systems are fundamental. This review has shown the applicability of the graphene family in several biomedical modalities, with particular attention for cancer therapy and diagnosis, as a potent theranostic. This ability is derivative from the considerable number of forms that the graphene family can assume. The graphene-based materials biodistribution profile, clearance, toxicity, and cytotoxicity, interacting with biological systems, are discussed here, focusing on its synthesis methodology, physicochemical properties, and production quality. Despite the growing increase in the bioavailability and toxicity studies of graphene and its derivatives, there is still much to be unveiled to develop safe and effective formulations.

Graphic abstract

Zinc(ii) and cadmium(ii) amorphous metal-organic frameworks (aMOFs): study of activation process and high-pressure adsorption of greenhouse gases

Two novel amorphous metal-organic frameworks (aMOFs) with chemical composition {[Zn2(MTA)]·4H2O·3DMF} n (UPJS-13) and {[Cd2(MTA)]·5H2O·4DMF} n (UPJS-14) built from Zn(ii) and Cd(ii) ions and extended tetrahedral tetraazo-tetracarboxylic acid (H4MTA) as a linker were prepared and characterised. Nitrogen adsorption measurements were performed on as-synthesized (AS), ethanol exchanged (EX) and freeze-dried (FD) materials at different activation temperatures of 60, 80, 100, 120, 150 and 200 °C to obtain the best textural properties. The largest surface areas of 830 m2 g-1 for UPJS-13 (FD) and 1057 m2 g-1 for UPJS-14 (FD) were calculated from the nitrogen adsorption isotherms for freeze-dried materials activated at mild activation temperature (80 °C). Subsequently, the prepared compounds were tested as adsorbents of greenhouse gases, carbon dioxide and methane, measured at high pressures. The maximal adsorption capacities were 30.01 wt% CO2 and 4.84 wt% CH4 for UPJS-13 (FD) and 24.56 wt% CO2 and 6.38 wt% CH4 for UPJS-14 (FD) at 20 bar and 30 °C.

A Novel D-A-D Photosensitizer for Efficient NIR Imaging and Photodynamic Therapy

Photodynamic therapy (PDT) has attracted great interest in cancer theranostics owing to its minimal invasiveness and low side effect. In PDT, photosensitizers are indispensable components that generate cytotoxic reactive oxygen species (ROS). Tremendous efforts have been devoted to optimizing the photosensitizer with enhanced ROS efficiency. However, to improve the precision and controllability for PDT, developing NIR imaging-guided photosensitizers are still urgent and challenging. Here, we have designed a novel photosensitizer 2Cz-BTZ which integrated with intense NIR emission and photoinduced singlet oxygen ¹ O₂ generation capabilities. Moreover, after loading the photosensitizers 2Cz-BTZ into biocompatible amphiphilic polymers F127, the formed 2Cz-BTZ@F127 nanoparticles (NPs) exhibited good photoinduced therapy as well as long-term in vivo imaging capabilities. Under these merits, the 2Cz-BTZ@F127 NPs showed NIR imaging-guided PDT, which paves a promising way for spatiotemporally precise tumor theranostics.