Latest ArticlesPhotothermal hydrogels with excellent photo responsive and thermal conversion ability had attract a great deal of attention from researchers to explore their biological applications. This review aimed to provide a comprehensive overview of photothermal hydrogels, focusing on their design principles, various functions, and biological applications. Firstly, several classifications of photothermal hydrogels were given according to different photothermal agents (metal, metal sulfide/oxide, MXene, carbon-based, dyes, black phosphorus, and polymer) utilized in hydrogel construction. The photothermal conversion mechanism and hydrogel fabrication were also discussed in detail. Then, the relationship between their photothermal conversion property and functions, together with some indispensable property such as biocompatibility, adhesion, mechanical properties, and self-healing properties was fully introduced. Furthermore, the applications of photothermal hydrogels in the biomedical (i.e., wound healing, antibacterial treatments, controlled drug release, bone repair, and tumor treatment) was summarized. Finally, the future opportunities and challenges of photothermal hydrogels were proposed. We believe that this review could provide a new horizon for further preparation of photothermal hydrogels, and could promote their applications in wider fields.
Sodium percarbonate (Na2CO3·1.5H2O2, SPC) has been extensively employed as a solid substitute of H2O2 for Fenton process in water treatment, because of its high stability during the production, transport, storage and usage. In addition, SPC can be applied in a wider range of work pH, it is also applied as a buffer in Fenton reaction for preventing a drop in pH. Herein, we have synthesized basic copper molybdate (BCM) nanoblocks with the molecular formula of Cu3(MoO4)2(OH)2 as an efficient and heterogeneous catalyst for antibiotics degradation via percarbonate activation. First, fully physical characterizations confirmed BCM nanocomposite exhibited a structure of nanoblocks. We also found that BCM/SPC system could work in a much wider pH range, compared with H2O2. Then, BCM/SPC system presented a good anti-interference ability for natural organic matter in OTC degradation. EPR results and Quenching tests confirmed that the co-presence of ·CO3−, ·O2−, 1O2 and ·OH in BCM/SPC system.
The occurrence of acquired resistance to cisplatin (DDP) that induces the toxic drug effects has always been a huge challenge and urgently needs to be resolved in the cancer treatment. The combination of anticancer drugs with different mechanisms can remarkably improve the chemotherapeutic efficiency. Given that glutathione (GSH) plays as the driving factors in the resistance of DDP, here we have firstly proposed a “three birds, one stone” based nanoplatform to achieve triple synergetic effects simultaneously addressing DDP resistance in non-small cell lung cancer (NSCLC). Specifically, we initially designed and synthesized a DDP prodrug [Pt(Ⅳ)] bridged silsesquioxane precursor (Pt-Si). Then Pt-Si and bis[3-(triethoxysilyl)propyl]diselenide (BTESePD) were integrated into the framework of mesoporous organosilica nanoparticles (MONs) to obtain a nanocarrier MONPt/Se. After loading with norcantharidin (NCTD) and modifying with the aptamer AS1411 based G-quadruplex (Apt), the Apt@NCTD@MONPt/Se exhibit impressive tumor homing capability. Once being endocytosed, (Ⅰ) the diselenide and -O-Pt(Ⅳ)-O- rich scaffold can be reduced by the excessive GSH, followed by (Ⅱ) breaking the redox homeostasis via GSH depletion and precise release of the DDP. Next, the encapsulated NCTD is also released along with the degradation of the nanocarriers thereby (Ⅲ) achieving the GSH depletion and synergistic anti-tumor effect of NCTD and DDP. Taken together, we believe this “one stone, three birds” strategy may be a promising paradigm to conquer drug resistance for clinical care.
Solar-driven H2O2 production and emerging organic pollutants (EOPs) elimination are of great significance from the perspective of environmental sustainability. The efficiency of the photocatalytic reaction system is the key challenge to be addressed. In this work, the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is demonstrated. Selected bipyridinium cation (TMAP) is complexed on a K+-incorporated carbon nitride (CNK) framework, and the combination of local polarization centers both on the surface (bipyridinium cation) and bulk (K+ cation) contributes to a superior photocatalytic H2O2 production performance, affording a remarkable H2O2 generation rate of 46.8 µmol h−1 mg−1 and a high apparent quantum yield (AQY) value of 77.5% under irradiation of 405 nm photons. As substantiated experimentally by steady state/transient spectroscopy techniques, the surface local polarization centers increase the population of the long-lived trapped electrons, and thereby promote the interfacial charge transfer process for chemical conversion reaction. The strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.
Post-synthetic installation strategy is an effective approach to improve the functions of metal-organic frameworks (MOFs). Herein, a pair of chiral MOFs is successfully constructed through solvothermal subcomponent self-assembly and exhibit circularly polarized luminescence (CPL). These MOFs contain coordinatively unsaturated Zn sites and channels, which allow the installation of pyridyl-terminated pillars into the original structure. Such a post-synthetic installation process reinforces the MOFs' rigidity and increases the photoluminescence quantum yields (PLQYs). Furthermore, the luminescence dissymmetry factors (glum) of these post-modified MOFs are amplified after installing the pillars. This work provides an appealing strategy for boosting the CPL performance of chiral MOFs.
Long-term fluorescence monitoring of subcellular organelles is crucial for cellular physiology and pathology studies. Lipid droplets (LDs) are increasingly recognized for their involvement in various biological processes, to influence disease development through diverse behaviors However, existing LD probes face challenges in achieving high targeting and long-term monitoring due to poor photostability and long-term phototoxicity. Carbon quantum dots (CQDs) have gained prominence due to their exceptional fluorescence properties, but their prevalent blue excitation wavelength presents difficulties for long-term imaging. Herein, we synthesized red-emissive carbon quantum dot (R-CQDs) with superior photobleaching resistance and red-emission, thus enabling harmlessly fluorescence monitoring of cells longer than 3 h. In addition, R-CQD exhibits suitable amphiphilicity and remarkable solvatochromic effect, allowing rapid targeting to LDs for immediate imaging without cumbersome washing steps. Hence, R-CQD shows high performance for extended observation of dynamic LD behavior in various biological processes, which is confirmed by documenting the course of LDs during starvation as well as lipotoxicity. Compared to commercial probes, R-CQD extends live cell imaging time by at least 9-fold, facilitating the study of LD behavioral characteristics under diverse physiological or pathological conditions. This work provides a reliable fluorescence tool for tracking intercellular microenvironment dynamically thus to understand the divers biological or disease mechanism.
The development of resistance against most of the available antibiotics has made Acinetobacter baumannii (A. baumannii) a pathogen of high risk. In this study, thirty novel berberine derivatives are rationally designed, synthesized, and evaluated for their synergistic antibacterial activities against A. baumannii. Among them, compound 2d shows the most potent synergetic effect to aztreonam against A. baumannii, including carbapenem-resistant and extended-spectrum β-lactamases-producing strains. Moreover, synergistic effects were observed for the combinations of 2d and different antibacterial used in clinical practices, indicating its potent broad-spectrum antibiotic-sensitizing effects against A. baumannii. The combination of 2d and aztreonam significantly improves the survival rates of G. mellonella larvae compared with aztreonam treatment alone. Mechanism studies indicate that 2d inhibits the drug efflux and iron acquisition of the bacteria by targeting the AdeB transporter protein, thus achieving a synergistic antimicrobial efficacy with different antibacterial agents. Therefore, berberine derivatives represent a new family of antimicrobial adjuvants against A. baumannii, with the advantage of dual-function antibacterial effect, and are worthy of further investigation.
The combination of interface engineering and defect engineering is a promising strategy for developing new semiconducting surface-enhanced Raman scattering (SERS) substrate. Herein, an organic/inorganic hybrid g-C3N4/TiO2-X heterojunction with synchronous generation of strong interface effect and abundant surface oxygen vacancy (OV) defect was prepared by a simple sol-hydrothermal procedure with a help of urea. Due to the improved substrate-to-molecule charge transfer (CT) from joint contribution of high-efficiency carrier separation induced by strong interface coupling effect and multiple CT paths derived from abundant surface OV, g-C3N4/TiO2-X substrate exhibits greatly enhanced SERS effect for non-resonant 4-mercaptobenzoic acid (4-MBA) probe. The enhancement factor of g-C3N4/TiO2-X substrate for 4-MBA is as high as 5.57 × 106, and the substrate exhibits ultra-high stability and excellent spectral reproducibility. More meaningfully, the developed g-C3N4/TiO2-X heterojunction can be used to execute an ultrasensitive detection for antibiotic residues in real water system, even comprehensive evaluation of multi-component residues.
Spin-orbit, charge-transfer intersystem crossing (SOCT-ISC) can directly overcome the disadvantages of the traditional heavy-atom effect and improve the generation efficiency of reactive oxygen species (ROS). Since orthogonal molecular orbitals of donor-acceptor (D-A) pairs favor the SOCT-ISC transition, herein aza-borondipyrromethenes (aza-BODIPYs) with 1,7-di-anthracyl groups (An-azaBDP) was successfully prepared, owing to steric hindrance to produce a big dihedral angle between the two molecular orbital (MO) planes. Moreover, according to density functional theory (DFT) and time-dependent density functional theory (TDDFT), the energy difference between the S1-T1 orbitals of An-azaBDP is small and more inclined towards ISC. An-azaBDP can effectively generate singlet oxygen under light irradiation. An-azaBDP with light irradiation can induce apoptosis in SW620 cells, and can serve as a potential candidate for the treatment of cancer cells and tumors.
Monosescinol A (1), the first example of sesquiterpene–polycyclic polyprenylated acylphloroglucinol (PPAP) adduct, which represented a new subclass of PPAP-type natural products, along with two new congeners with normal spiro 6/6/5 tricyclic architecture, were isolated from Hypericum longistylum. Monosescinol A possessed an unprecedented 6/5/5/6/6 pentacyclic carbon skeleton that might be assembled from the 6/6/5 carbon skeleton, via the splitting decomposition of C-3/C-14, and the attack from the C-3 in the PPAP core to C-28 in sesquiterpene section. In addition, we have firstly confirmed that 24R configuration was existed in sec–Bu containing PPAPs by single crystal diffraction data analysis of monosescinol B (2), that might provide an enlightenment in the configurational determination of sec–Bu containing PPAPs. Significantly, further pharmacological research has found that compound 1 exhibited remarkable pharmacological effects against acute myeloid leukemia (AML) cell lines, with direct inhibition of mitochondrial complex Ⅴ and an increase in mitochondrial membrane potential, and led to an induction of oxidative stress, endogenous inflammation, and apoptosis of AML cells.