Tetrakis 4-carboxyphenyl Porphyrin Research Articles

Textural Precursor Compositions Harvested for Independent Signal Generators: Scaling Micron-Sized Flower-Like Metal-Organic Frameworks as Amplifying Units for Dual-Mode Glycoprotein Assay.

In this work, a micron-sized flower-like metal-organic frameworks (MOFs)-based boronate-affinity sandwich-type immunoassay was fabricated for the dual-mode glycoprotein assay. For proof of concept, the flower-like MOFs were synthesized from transition Cu nodes and tetrakis (4-carboxyphenyl) porphyrin (TCPP) ligands by spontaneous standing assembly. In addition, the specificity toward glycoprotein involved the antigen recognition as well as covalent bonding via the boronate-glycan affinity, and the immediate signal responses were initiated by textural decomposition of the flower-like MOFs. Intriguingly, Cu nodes, of which the valence state is dominant by CuI species, can endow the Fenton-like catalytic reaction of the fluorogenic substrate for generating fluorescence signals. For benefits, TCPP ligands, in which each TCPP molecule has four guest donors, can provide multiple valences for the assembly of cyclodextrin-capped gold nanoparticles via host-guest interaction for colorimetry output. Albeit important, the scaling micrometer patterns for the flower-like MOFs carrying numerous Cu nodes and TCPP ligands can also function as amplifying units, signifying the output signal. The detection limit of the dual-mode glycoprotein assay can reach 10.5 nM for the fluorescence mode and 18.7 nM for the colorimetry mode, respectively. Furthermore, the merits of harvesting different signal generators toward the multimodal readout patterns can allow the mutual verification and make the analytical results more reliable. Collectively, our proposed assay may offer a new idea in combining the inherent textural merits from MOFs for dual signal generators, which can also emphasize accurate detection capability for glycoprotein assay.

Bio-catalytic nanoparticle shaping for preparing mesoscopic assemblies of semiconductor quantum dots and organic molecules.

We report a unique bio-catalytic nanoparticle shaping (BNS) method for preparing a variety of mesoscopic particles by a facile process. For example, the BNS method affords mesoscopic QD assembly dispersions. Large-size sedimentations (>1 μm) of QDs are first formed using oligo-L-lysine linkers. These then undergo controlled enzymatic cleavage of the linkers using trypsin, which surprisingly leads to mesoscopic particles about 84 nm in size with a narrow size distribution. A detailed mechanism of the BNS method is investigated using tetrakis(4-carboxyphenyl)porphyrin (TCPP), instead of QDs, as a probe molecule. Interestingly, the BNS method can also be applied to other combinations of enzymes and enzymatically degradable linkers, such as hyaluronidase with hyaluronan. As a potential application, the mesoscopic particles of QDs and oligo-lysine exhibit their ability to act as a drug delivery carrier originating from the features of both QDs and oligo-lysine. The BNS method demonstrates the universality and versatility of preparing mesoscopic particles and opens new doors for studying QD assemblies and molecular-based mesoscopic particles.

Photoactive polymer coatings for antibacterial applications

Because bacteria can readily induce illnesses in the human body, research into new bactericidal approaches remains relevant to the global community. Photoactive materials (e.g., photocatalysts) provide an environmentally-friendly method for killing bacteria with light. By means of light-mediated reactive oxygen generation, photocatalysts are capable of disrupting bacterial membranes. Much research on antibacterial surfaces has focused on planar substrates or physisorbed coatings, which often provide small active surface areas and limited surface-to-volume ratios, and thereby create a need for new design strategies to incorporate photocatalysts onto more scalable supports. To this end, this contribution describes the synthesis of particle-tethered polymer brush coatings, crosslinked with the organic photocatalyst tetrakis(4-carboxyphenyl)porphyrin (TCPP). Successful engineering on SiO2 surfaces was confirmed using X-ray photoelectron spectroscopy, tensiometry, and ellipsometry. Singlet oxygen (1O2) generation was confirmed through dimethyl sulfoxide oxidation experiments under visible (blue) light and bactericidal activity against Escherichia coli was verified through live/dead assays and cell viability tests.

Photosynthesis of H2O2 in pure water over 2D metal-organic frameworks film by co-doping Ga and porphyrin

Hydrogen peroxide (H2O2) is a clean oxidizing agent and potential energy carrier. Photocatalytic H2O2 production has garnered increased attention due to its green and energy-saving process. However, existing photocatalysts face several challenges, such as limited response to visible light, the requirement for sacrificial reagents, and complications in powder recycling. In this work, we synthesized two-dimensional (2D) NH2-MIL-53(Al) films co-modified with Ga and tetrakis (4-carboxyphenyl) porphyrin (TCPP) with enhanced photocatalytic activity of 268.7 µmol∙g−1∙h−1 from only O2 and pure H2O, reaching 3.5 times higher than pure NH2-MIL-53(Al). Notably, in comparison with other reported MOF photocatalysts, NMA-Ga5%-L30 stands out with the highest photocatalytic H2O2 generation activity in a pure water system under visible light. Moreover, this sample film was readily recovered from a photocatalytic system and exhibits significant cycling stability. The heightened photocatalytic activity is attributed to the dual modification, which not only reduces the photogenerated band gap but also promotes the charge carrier’s separation and transfer. This work provides a strategy for the design of MOFs-based photocatalysts with easy recycle properties for artificial photosynthesis of H2O2.

Ingenious Modulation of Third-Order Nonlinear Optical Response of Zr-MOFs through Defect Engineering Based on a Mixed-Linker Strategy.

Defect engineering plays a pivotal role in regulating electronic structure and facilitating charge transfer, yielding captivating effects on third-order nonlinear optical (NLO) properties. In this work, we utilized a mixed-linker strategy to intentionally disrupt the initial periodic arrangement of UiO-66 and construct defects. Specifically, we incorporated tetrakis(4-carboxyphenyl)porphyrin (TCPP) with an exceptionally electron-rich delocalization system into the framework of UiO-66 using a one-pot solvothermal method, ingeniously occupying the partial distribution sites of the Zr6 clusters. Compared to UiO-66, the NLO absorption and refraction performance of TCPP/UiO-66 were significantly improved. Additionally, due to the presence of nitrogen-rich sites that can accommodate metal ions in the porphyrin ring of TCPP, Co(II), Ni(II), Cu(II), and Zn(II) are introduced into TCPP/UiO-66, extending the d-π conjugation effect to further regulate the defects. The NLO absorption behavior transforms saturation absorption (SA) to reverse saturation absorption (RSA), while the refraction behavior shifts from self-defocusing to self-focusing. This work shows that defects can effectively regulate the electronic structure, while TCPP plays a crucial role in significantly enhancing electron delocalization.

Influence of Humidity on Layer-by-Layer Growth and Structure in Coordination Networks.

Metal-organic frameworks (MOFs) are promising materials because of their high designability of pores and functionalities. Especially, MOF thin films and their properties have been investigated toward applications in nanodevices. Typically, MOF thin films are fabricated by using a bottom-up method such as layer-by-layer (LbL) growth in air. Because the water molecules can coordinate and be replaced with organic linkers during synthesis, humidity conditions will be expected to influence the LbL growth processes. In this study, we fabricated MOF thin films composed of Zn2+, tetrakis-(4-carboxyphenyl)-porphyrin (TCPP), and 4,4'-bipyridyl (bpy) at 10 and 40% relative humidity (RH) conditions. Then, we investigated the humidity effects on chemical compositions of TCPP and bpy, periodic structure, orientation, and surface morphology. At high RH, coordination replacement of water with the organic linkers becomes more competitive than that at low RH, resulting in a different TCPP/bpy composition ratio between the two RH conditions. Also, more frequent coordination replacements of water with the organic linkers at high RH led to the formation of phases other than that observed at low RH, loss of growth orientation, and rough surface. The findings clarified the importance of controlling the RH condition during LbL growth to obtain the desired coordination networks.

Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm.

Given the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin-uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga-CT@P nanocomposites constructed with gallium, copper-doped tetrakis (4-carboxyphenyl) porphyrin (TCPP) metal-organic framework, and polyamine-amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium-incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a "give and take" approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real-time fluorescent iron-sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga-CT@P nanocomposites induced long-term iron starvation, which affected iron-sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.

Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm

AbstractGiven the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin‐uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga‐CT@P nanocomposites constructed with gallium, copper‐doped tetrakis (4‐carboxyphenyl) porphyrin (TCPP) metal–organic framework, and polyamine‐amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium‐incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a “give and take” approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real‐time fluorescent iron‐sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga‐CT@P nanocomposites induced long‐term iron starvation, which affected iron‐sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.

Dressing and undressing MOF nanophotosensitizers to manipulate phototoxicity for precise therapy of tumors

Photodynamic therapy (PDT) is a clinically approved treatment for tumors, and it relies on the phototoxicity of photosensitizers by producing reactive oxygen species (ROS) to destroy cancer cells under light irradiation. However, such phototoxicity is a double-edged sword, which is also harmful to normal tissues. To manipulate phototoxicity and improve the therapy effect, herein we have proposed a dressing-undressing strategy for de-activating and re-activating therapy functions of photosensitizer nanoparticles. One kind of metal organic framework (PCN-224), which is composed of Zr(IV) cation and tetrakis (4-carboxyphenyl) porphyrin (TCPP), has been prepared as a model of photosensitizer, and it has size of ∼70 nm. These PCN-224 nanoparticles are subsequently coated with a mesoporous organic silica (MOS) shell containing tetrasulfide bonds (-S-S-S-S-), realizing the dressing of PCN-224. MOS shell has the thickness of ∼20 nm and thus can block 1O2 (diffusion distance: <10 nm), deactivating the phototoxicity and preventing the damage to skin and eyes. Furthermore, PCN-224@MOS can be used to load chemotherapy drug (DOX·HCl). When PCN-224@MOS-DOX are mixed with glutathione (GSH), MOS shell with -S-S-S-S- bonds can be reduced by GSH and then be decomposed, which results in the undressing and then confers the exposure of PCN-224 with good PDT function as well as the release of DOX. When PCN-224@MOS-DOX dispersion is injected into the mice and accumulated in the tumor, endogenous GSH also confers the undressing of PCN-224@MOS-DOX, realizing the in-situ activation of PDT and chemotherapy for tumor. Therefore, the present study not only demonstrates a general dressing-undressing strategy for manipulating phototoxicity of photosensitizers, but also provide some insights for precise therapy of tumors without side-effects. Statement of significancePhotosensitizers can generate reactive oxygen species (ROS) under light radiation to destroy cancer cells. However, this phototoxicity is a double-edged sword and also harmful to normal tissues such as the skin and eyes. To control phototoxicity and improve therapeutic efficacy, we prepared a PCN-224@MOS-DOX nanoplatform and proposed a dressing and undressing strategy to deactivate and reactivate the therapeutic function of the photosensitizer nanoparticles. The MOS shell can block the diffusion of 1O2, eliminate phototoxicity, and prevent damage to the skin and eyes. When injected into mice and accumulated in tumors, PCN-224@MOS-DOX dispersions are endowed with an endogenous GSH-driven undressing effect, achieving in situ activation of PDT and tumor chemotherapy.

Photocatalytic H2 Generation: Controlled and Optimized Dispersion of Single Atom Co-Catalysts Based on Pt-TCPP Planar Adsorption on TiO2.

When using single atoms (SAs) as a co-catalyst in photocatalytic H2 generation, achieving a well-dispersed, evenly distributed and adjustable SA surface density on a semiconductor surface is a challenging task. In the present work we use the planar adsorption of tetrakis-(4-carboxyphenyl)-porphyrin (TCPP) and its platinum coordinated analogue, Pt-TCPP, onto anatase TiO2 surfaces to establish a spatially controlled decoration of SAs. We show that the surface Pt SA density can be very well controlled by co-adsorption of Pt-TCPP and TCPP in the planar monolayer regime, and by adjusting the Pt-TCPP to TCPP ratio a desired well dispersed surface density of SAs up to 2.6×105 atoms μm-2 can be established (which is the most effective Pt SA loading for photocatalysis). This distribution and the SA state are maintained after a thermal treatment in air, and an optimized SA density as well as a most active form of Pt for photocatalytic H2 evolution can be established and maintained.

Photocatalytic H2 Generation: Controlled and Optimized Dispersion of Single Atom Co‐Catalysts Based on Pt‐TCPP Planar Adsorption on TiO2

AbstractWhen using single atoms (SAs) as a co‐catalyst in photocatalytic H2 generation, achieving a well‐dispersed, evenly distributed and adjustable SA surface density on a semiconductor surface is a challenging task. In the present work we use the planar adsorption of tetrakis‐(4‐carboxyphenyl)‐porphyrin (TCPP) and its platinum coordinated analogue, Pt‐TCPP, onto anatase TiO2 surfaces to establish a spatially controlled decoration of SAs. We show that the surface Pt SA density can be very well controlled by co‐adsorption of Pt‐TCPP and TCPP in the planar monolayer regime, and by adjusting the Pt‐TCPP to TCPP ratio a desired well dispersed surface density of SAs up to 2.6×105 atoms μm−2 can be established (which is the most effective Pt SA loading for photocatalysis). This distribution and the SA state are maintained after a thermal treatment in air, and an optimized SA density as well as a most active form of Pt for photocatalytic H2 evolution can be established and maintained.

Sorafenib and tetrakis (4-carboxyphenyl) porphyrin assembled nanoparticles for synergistic targeted chemotherapy and sonodynamic therapy of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is characterized by a high degree of malignancy and mortality. Sorafenib (SOR), a multi-kinase inhibitor, is clinically used in the treatment of HCC. However, SOR suffers from serious side effects and drug resistance. The development of novel therapeutic strategies for HCC therapy is urgently needed. Sonodynamic therapy (SDT) has unique advantages in treating deep tumors due to the merits of deep tissue penetration, low side effects, and the absence of drug resistance. Here, we developed multifunctional nanoparticles (NPs) termed SOR-TCPP@PEG-FA by assembling SOR, tetrakis (4-carboxyphenyl) porphyrin (TCPP), and folic acid (FA)-modified DSPE-PEG. The FA group enhances the tumor targeting capability of these NPs, while TCPP generates ROS under ultrasound (US) irradiation, which are toxic to tumor cells, and SOR with chemotherapeutic effects is released, thus realizing the synergistic SDT and chemotherapy of tumors.

Imaging assessment of photosensitizer emission induced by radionuclide-derived Cherenkov radiation using charge-coupled device optical imaging and long-pass filters.

Radionuclides produce Cherenkov radiation (CR), which can potentially activate photosensitizers (PSs) in phototherapy. Several groups have studied Cherenkov energy transfer to PSs using optical imaging; however, cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge. Many laboratories face the need for expensive dedicated equipment. To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs. The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs. To mitigate the need for expensive dedicated equipment and achieve the aim of the study, we developed a method that utilizes a charge-coupled device optical imaging system and appropriate long-pass filters of different wavelengths (manual sequential application of long-pass filters of 515, 580, 645, 700, 750, and 800 nm). Tetrakis (4-carboxyphenyl) porphyrin (TCPP) was utilized as a model PS. Different doses of copper-64 (64CuCl2) (4, 2, and 1 mCi) were used as CR-producing radionuclides. Imaging and data acquisition were performed 0.5 h after sample preparation. Differential image analysis was conducted by using ImageJ software (National Institutes of Health) to visually evaluate TCPP fluorescence. The maximum absorbance of TCPP was at 390-430 nm, and the emission peak was at 670 nm. The CR and CR-induced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above. The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity (total flux) difference between 64CuCl2 + TCPP and 64CuCl2. Moreover, the differential fluorescence images of TCPP were obtained by subtracting the 64CuCl2 image from the 64CuCl2 + TCPP image. The experimental results considering different 64CuCl2 doses showed a dose-dependent trend. These results demonstrate that a bioluminescence imaging device coupled with different long-pass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP. This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs.

Metal–organic framework electrocatalysis: More than a sum of parts?

The ever cheapening renewable energy calls for an effective means of storing and using electricity. Electrocatalysis is key for transforming electricity into chemical bonds. However, electrolysis is limited by the catalyst at the electrodes. In this work, we explore metal–organic frameworks (MOFs) as potential electrocatalysts. We investigate MOF-525, consisting of Zr nodes and tetrakis(4-carboxyphenyl)porphyrin (TCPP) linkers. We show using density functional theory simulations that metal incorporation in the ligand changes the reactivity in an electrochemical environment. Furthermore, we find that the MOF-derived porphyrin structure has a similar catalytic performance to the MOF itself for the hydrogen evolution, oxygen reduction, and CO2 reduction reactions. Our findings highlight the challenge of using and reporting catalysis from complex hybrid materials, such as MOFs.

Porphyrin sensitized ZnWO4 nanosheets with CuO nanoparticles for photocatalytic hydrogen evolution

Photocatalytic hydrogen production is a promising technique for solar-to-chemical energy conversion. However, the efficiency of this method is greatly limited by the need to develop efficient photocatalysts. In this study, we rationally designed an organic–inorganic hybrid material as a photocatalyst for hydrogen production. ZnWO4 nanosheets were fabricated via a hydrothermal reaction, before decorating with CuO nanoparticles as a co-catalyst for hydrogen evolution and tetrakis(4-carboxyphenyl) porphyrin (TCPP) as a photosensitizer. The as-fabricated ZnWO4/CuO/TCPP obtained excellent photocatalytic hydrogen evolution (1.84 mmol g−1 h−1) under the optimized reaction conditions, which was about 4.9 times higher compared with that using the pristine ZnWO4. This significant enhancement was ascribed to the efficient charge separation by CuO and light absorption extension by porphyrin. Thus, we demonstrated a good example of efficient hydrogen production based on the rational design of photocatalysts.

Europium- and Black Phosphorus-Functionalized Porphyrin as an l-Arginine Sensor and l-Arginine-Activated PDT/PTT Agent for Bacterial Treatment.

The attenuation of bacterial metabolism provides an adjunct to the treatment of bacterial infections. To develop a bacterial eradication agent, a bioactivatable material (BP@Eu-TCPP) was designed and synthesized by coordination and reduction of europium(III) with thin-layer black phosphorus (BP) and tetrakis (4-carboxyphenyl) porphyrin (TCPP). The existence of the P-Eu bond and Eu2+ 3d5/2 in X-ray photoelectron spectroscopy confirmed the successful synthesis of BP@Eu-TCPP. This material showed high fluorescence sensitivity to l-Arginine (l-Arg) and the main binding ratio of BP@Eu-TCPP to l-Arg was ca. 1:2 or 1:3, with the limit of detection of 4.0 μM. The material also showed good photothermal properties and stability, with a photothermal conversion efficiency of 37.3%. Although metal coordination has blocked the generation of 1O2, the addition of l-Arg to BP@Eu-TCPP can restore 1O2 generation upon red light-emitting diode (LED) light irradiation due to the formation of water-soluble Arg-TCPP species. Additionally, BP@Eu-TCPP was enabled to change the bacterial membrane and interfered with the bacterial iron absorption that effectively contributes to bacterial eradication. Such BP@Eu-TCPP is promised to be a novel material for the detection of l-Arg and l-Arg-activated photodynamic therapy.

Pore Modulation of Hydrogen-Bonded Organic Frameworks for Efficient Separation of Propylene.

Developing hydrogen-bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen-bonded network to achieve high-performance HOFs. Here, a series of HOFs termed as HOF-ZSTU-M (M=1, 2, and 3) with different pore structures are obtained by introducing structure-directing agents (SDAs) into the hydrogen-bonding network of tetrakis (4-carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi-dimensional. Single-crystal X-ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen-bonding models dominated by SDAs. HOF-ZSTU-2, which forms a strong layered hydrogen-bonding network with ammonium (NH4 + ) through multiple carboxyl groups, has a suitable 1D "pearl-chain" channel for the selective capture of propylene (C3 H6 ). At 298 K and 1 bar, the C3 H6 storage density of HOF-ZSTU-2 reaches 0.6 kg L-1 , representing one of the best C3 H6 storage materials, while offering a propylene/propane (C3 H6 /C3 H8 ) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3 H6 at different locations in the pearl-chain channel. Dynamic breakthrough tests confirm that HOF-ZSTU-2 can effectively separate C3 H6 from multi-mixtures.

Pore Modulation of Hydrogen‐Bonded Organic Frameworks for Efficient Separation of Propylene

AbstractDeveloping hydrogen‐bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen‐bonded network to achieve high‐performance HOFs. Here, a series of HOFs termed as HOF‐ZSTU‐M (M=1, 2, and 3) with different pore structures are obtained by introducing structure‐directing agents (SDAs) into the hydrogen‐bonding network of tetrakis (4‐carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi‐dimensional. Single‐crystal X‐ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen‐bonding models dominated by SDAs. HOF‐ZSTU‐2, which forms a strong layered hydrogen‐bonding network with ammonium (NH4+) through multiple carboxyl groups, has a suitable 1D “pearl‐chain” channel for the selective capture of propylene (C3H6). At 298 K and 1 bar, the C3H6 storage density of HOF‐ZSTU‐2 reaches 0.6 kg L−1, representing one of the best C3H6 storage materials, while offering a propylene/propane (C3H6/C3H8) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3H6 at different locations in the pearl‐chain channel. Dynamic breakthrough tests confirm that HOF‐ZSTU‐2 can effectively separate C3H6 from multi‐mixtures.

Oxygen-Generating Organic/Inorganic Self-Assembled Nanocolloids for Tumor-Activated Dual-Model Imaging-Guided Photodynamic Therapy.

Tumor phototheranostics is usually compromised by the hypoxic tumor microenvironment and poor theranostic efficiency. The interplay between organic polymers and inorganic nanoparticles in novel nanocomposites has proven to be advantageous, overcoming previous limitations and harnessing their full potential through activation via the tumor microenvironment. This study successfully fabricated hypoxia-activated nanocolloids called HOISNDs through a process of self-assembly involving superparamagnetic iron oxide nanoparticles (SPIONs) and an organic polymer ligand called tetrakis(4-carboxyphenyl) porphyrin (TCPP)-engineered organic polymer ligand [methoxy poly(ethyleneglycol)-block-poly(dopamine-ethylenediamine-conjugated-4-nitrobenzyl chloroformate)-l-glutamate, mPEG-b-P(Dopa-EDA-co-NBCF)LG-TCPP)]. The SPIONs act as an oxygen generator to overcome the challenges posed by hypoxic tumors and enable the use of hypoxic-activatable MR/fluorescence dual-modal imaging-guided photodynamic therapy (PDT). The colloid stability of these HOISNDs proved to be exceptional in diverse biomimetic environments. Furthermore, they not only augment T2-weighted contrast capability as an MRI contrast agent but also function as an oxygen-producing device to amplify the generation and release of reactive oxygen species (ROS). The HOISNDs can significantly target to tumor sites through the enhanced permeability and retention (EPR) effect with prolonged blood circulation time and subsequently are effectively endocytosed into a hypoxic intracellular environment that "turn on" the imaging function and photodynamic activity. Moreover, HOISNDs possess the ability to effectively decompose naturally occurring H2O2 into oxygen (O2) within the tumor utilizing the Fenton reaction. This method can mitigate the impact of hypoxia on oxygen-dependent PDT. The outcomes of in vivo diagnostic and therapeutic evaluations indicated that HOISNDs are a highly promising tool for dual-model imaging-guided cancer theranosis by ameliorating hypoxic conditions and augmenting PDT efficiency.

A multifunctional metal-organic framework nanosystem disrupts redox homeostasis for synergistic therapy

Synergistic therapies of photodynamic therapy (PDT) and chemodynamic therapy (CDT) via metal-organic frameworks (MOF) for cancer treatment have recently attracted a lot of attentions because of the limitations of insufficient reactive oxygen species (ROS) in single-modality approaches. However, few studies explored on the use of increased ROS synergized with chemotherapy (CT) to address the issue of inadequate anti-tumor efficacy in single-modality regimens. Here, the desired cascade nanoplatforms (noted as MOF(Cu)@Dox-PL NPs) were fabricated by a solvothermal method using tetrakis (4-carboxyphenyl) porphyrin (TCPP) and zirconyl(di)chloride octahydrate (ZrOCl2·8H2O) as raw material, followed by Cu2+ introduced into the porphyrin ring and doxorubicin (DOX) loaded into the nanoframework. In addition, the nanoparticles (NPs) were electrostatically and hydrophobically coated with phospholipid (PL) to improve the biocompatibility of the nanosystems. Singlet oxygen (1O2) was created by the MOF(Cu)@Dox-PL NPs to disturb intracellular redox equilibrium. The acidic microenvironment in cancer cells may cause the prior release of DOX, which encourages the production of hydrogen peroxide (H2O2). And the doped Cu2+ could deplete overexpressed reduced glutathione (GSH) to produce hydroxyl radicals (·OH) by catalyzing H2O2, further causing redox dyshomeostasis. In vivo experiments revealed that MOF(Cu)@Dox-PL nanosystem possessed good biosafety and a compelling therapeutic effect in 4T1 tumor-bearing mice. As a novel nanosystem, MOF(Cu)@Dox-PL NPs showed great potential in synergistic therapy based on redox dyshomeostasis for improving anti-tumor efficacy with high specificity.