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Extensive recent efforts have been put on the design of high-performance organic near-infrared (NIR) photothermal agents (PTAs), especially over NIR-II bio-window (1000-1350 nm). So far, the development is mainly limited by the rarity of molecules with good NIR-II response. Here, we report organic nanoparticles of intermolecular charge-transfer complexes (CTCs) with easily programmable optical absorption. By employing different common donor and acceptor molecules to form CTC nanoparticles (CT NPs), absorption peaks of CT NPs can be controllably tuned from the NIR-I to NIR-II region. Notably, CT NPs formed with perylene and TCNQ have a considerably red-shifted absorption peak at 1040 nm and achieves a good photothermal conversion efficiency of 42 % under 1064 nm excitation. These nanoparticles were used for antibacterial application with effective activity towards both Gram-negative and Gram-positive bacteria. This work opens a new avenue into the development of efficient PTAs.

This letter is aimed to develop a general strategy to fabricate polypseudorotaxanes with controlled antibacterial activity based on cationic polymers. As a proof of concept, the commercially available antibacterial cationic polymer, e-poly-l-lysine hydrochloride, was chosen for the demonstration. Using host–guest chemistry, cucurbit[7]uril (CB[7]), a water-soluble macrocyclic host, was employed to bind with the positive charge and hydrophobic component on e-poly-l-lysine hydrochlorides for antibacterial regulation. In this way, by tuning the ratio of CB[7] to the cationic polymer, the antibacterial polypseudorotaxane can be obtained, and the antibacterial efficiency can be well tuned from 5% to 100%. This line of research will enrich the field of cationic polymers and polypseudorotaxanes with important functions on precise control over antibacterial activity.

Because of the steady increase in multi-drug-resistant bacterial infections, we developed a viable treatment strategy using new antibacterial nanomaterials with photosensitizing effects. In this work, three triphenylamine derivates (TPA-2PE, TPA-PCN, and TPA-2PCN) and amphiphilic polystyrene maleic anhydride (PSMA) were used to successfully prepare three corresponding nanoparticles. Compared to TPA-2PE, the introduced cyano unit resulted in a redshift for TPA-PCN and TPA-2PCN with near-infrared (NIR) emission. The specific aggregation-induced emission (AIE) characteristic contributed to the retentive photophysical property and the increased fluorescence quantum yield (QY) of these luminous molecules in nanoparticles. Our in vitro study indicated that the nanoparticles were able to tightly bind to the surface of bacteria by hydrogen bond interaction, and their bacterial toxicity was successfully directed against antibiotic-resistant Escherichia coli. The bactericidal performance was further amplified under white light irradiation by the supplied photosensitizing effect. Additionally, the killed bacteria were stained with the nanoparticles and subsequently emitted NIR emission, regardless of the interference of bacterial autofluorescence. The sterilization effects of the nanoparticles were tracked in situ and qualitatively characterized by the NIR self-reporting function. In the protocol reported herein, we describe all the essential factors for addressing antibiotic resistance, and therefore, this work includes all the necessary criteria for designing additional antibacterial nanomaterials in the future.

It is undoubted the important role of cells in biology and medicine, but worldwide misidentified and cross-contaminated cell lines have caused much trouble in related fields. Herein, three kinds of supramolecular AIE (aggregation-induced emission) nanoassemblies were constructed by the host-guest interaction between tetraphenylethene (TPE) derivatives and cucurbit[8]uril (CB[8]). Based on the recognized mechanism of AIE, the TPE derivatives could achieve stronger fluorescence emission and higher fluorescence quantum yield after assembling with CB[8]. Moreover, the constructed supramolecular AIE complexes obtained well-confirmed nanostructures and exhibited different sizes and shapes. Correspondingly, they generated characteristic biological properties and fluorescence enhancement of cells. Inspired by the concept of Big Data Analysis, these fluorescence signals were further transformed into a unique fingerprint of cells via linear discriminant analysis. Immediately, we realized the veracious identification between a normal cell line, two cancer cell lines, and two metastasized cancer cell lines in a qualitative analysis. More importantly, it was well used to monitor the evaluation of cross-contaminated cells and the discrimination of cancer cells. As a proper bioapplication of ideal supramolecular nanomaterials, this system was easy to learn and apply, and the whole procedure was kept to 20 min, without cell disruption, centrifugation, or washing steps.

Due to the excellent properties including high specificity, low side-effect and good biocompatibility, conjugated polymer nanomaterials have been served as efficient anticancer reagents in the past decades. According to the developed anticancer systems based on conjugated polymer nanomaterials, it could be summarized into three main cancer therapy strategies: photodynamic therapy(PDT), photothermal therapy(PTT) and combination therapy. In this mini review, we provide a brief introduction to three different cancer therapy modes, their mechanisms and potential biological applications. Furthermore, some perspectives on the further development of conjugated polymer nanomaterials are proposed in the territory of anticancer precision medicine.

Visually identifying pathogens favors rapid diagnosis at the point-of-care testing level. Here, we developed a microenvironment-sensitive aggregation-induced emission luminogen (AIEgen), namely IQ–Cm, for achieving fast discrimination of Gram-negative bacteria, Gram-positive bacteria and fungi by the naked-eye. With a twisted donor–acceptor and multi-rotor structure, IQ–Cm shows twisted intramolecular charge transfer (TICT) and AIE properties with sensitive fluorescence color response to the microenvironment of pathogens. Driven by the intrinsic structural differences of pathogens, IQ–Cm with a cationic isoquinolinium moiety and a membrane-active coumarin unit as the targeting and interacting groups selectively locates in different sites of three pathogens and gives three naked-eye discernible emission colors. Gram-negative bacteria are weak pink, Gram-positive bacteria are orange-red and fungi are bright yellow. Therefore, based on their distinctive fluorescence response, IQ–Cm can directly discriminate the three pathogens at the cell level under a fluorescence microscope. Furthermore, we demonstrated the feasibility of IQ–Cm as a visual probe for fast diagnosis of urinary tract infections, timely monitoring of hospital-acquired infection processes and fast detection of molds in the food field. This simple visualization strategy based on one single AIEgen provides a promising platform for rapid pathogen detection and point-of-care diagnosis., A simple AIEgen with three emission colors achieves rapid identification of Gram-negative bacteria, Gram-positive bacteria and fungi.

Along with the rapid appearance of superbacteria with multidrug resistance, it is a challenge to develop new antibacterial materials to address this big issue. Herein, we report a novel amine group-modified fullerene derivative (C70-(ethylenediamine)8 abrr. C70-(EDA)8), which reveals a high performance in killing superbacteria, and most importantly, it shows negligible toxicity to the mammalian cells. The strong antibacterial ability of this material was attributed to its unique molecular structure. On one hand, amino groups on the EDA part make it easy to affix onto the outer membrane of multidrug resistance Escherichia coli by electrostatic interactions. On the other hand, the hydrophobic surface on the C70 part makes it easy to form a strong hydrophobic interaction with the inner membrane of bacteria. Finally, C70-(EDA)8 leads to the cytoplast leakage of superbacteria. In contrast, the C70-(EDA)8 is nontoxic for mammalian cells due to different distributions of the negative charges in the cell membrane. In vivo studies indicated that C70-(EDA)8 mitigated bacterial infection and accelerated wound healing by regulating the immune response and secretion of growth factors. Our amine group-based fullerene derivatives are promising for clinical treatment of wound infection and offer a new way to fight against the superbacteria.

The development of effective antifungal agents remains a big challenge in view of the close evolutionary relationship between mammalian cells and fungi. Moreover, rapid mutations of fungal receptors at the molecular level result in the emergence of drug resistance. Here, with low tendency to develop drug-resistance, the subcellular organelle mitochondrion is exploited as an alternative target for efficient fungal killing by photodynamic therapy (PDT) of mitochondrial-targeting luminogens with aggregation-induced emission characteristics (AIEgens). With cationic isoquinolinium (IQ) moiety and proper hydrophobicity, three AIEgens, namely, IQ-TPE-2O, IQ-Cm, and IQ-TPA, can preferentially accumulate at the mitochondria of fungi over the mammalian cells. Upon white light irradiation, these AIEgens efficiently generate reactivesup1/supOsub2/sub, which causes irreversible damage to fungal mitochondria and further triggers the fungal death. Among them, IQ-TPA shows the highest PDT efficiency against fungi and negligible toxicity to mammalian cells, achieving the selective and highly efficient killing of fungi. Furthermore, we tested the clinical utility of this PDT strategy by treating fungal keratitis on a fungus-infected rabbit model. It was demonstrated that IQ-TPA presents obviously better therapeutic effects as compared with the clinically used rose bengal, suggesting the success of this PDT strategy and its great potential for clinical treatment of fungal infections.

Bacteria infected cells acting as “Trojan horses” not only protect bacteria from antibiotic therapies and immune clearance, but also increase the dissemination of pathogens from the initial sites of infection. Antibiotics are hard and insufficient to treat such hidden internalized bacteria, especially multidrug‐resistant (MDR) bacteria. Herein, aggregation‐induced emission luminogens (AIEgens) such as N,N‐diphenyl‐4‐(7‐(pyridin‐4‐yl) benzo [c] [1,2,5] thiadiazol‐4‐yl) aniline functionalized with 1‐bromoethane (TBP‐1) and (3‐bromopropyl) trimethylammonium bromide (TBP‐2) (TBPs) show potent broad‐spectrum bactericidal activity against both extracellular and internalized Gram‐positive pathogens. TBPs trigger reactive oxygen species (ROS)‐mediated membrane damage to kill bacteria, regardless of light irradiation. TBPs effectively kill bacteria without the development of resistance. Additionally, such AIEgens activate mitochondria dependent autophagy to eliminate internalized bacteria in host cells. Compared to the routinely used vancomycin in clinic, TBPs demonstrate comparable efficacy against methicillin‐resistant Staphylococcus aureus (MRSA) in vivo. The studies suggest that AIEgens are promising new agents for the treatment of MDR bacteria associated infections., Aggregation‐induced emission luminogens (AIEgens) offer great potentials to track and dissect their modes of action in bacteria and pharmacokinetics processes in hosts. AIEgens serve as a novel class of antibiotics by triggering reactive oxygen species (ROS)‐mediated membrane damage and by activating mitochondria dependent autophagy to kill bacteria, which are promising adjuvants to boost mammalian cells for bacterial clearance and treatment of MRSA associated peritonitis.

Silkworm silk is a promising natural biopolymer for textile and biomedical applications for its remarkable flexibility, excellent biocompatibility and controllable biodegradability. The functionalization of silks makes them more versatile for flexible displays and visible bioscaffolds. However, fluorescent silks are normally fabricated through unstable physical absorption or complicated chemical reactions under harsh conditions. Herein, we developed a simple strategy for preparing fluorescent silks. Five aggregation-induced emission luminogens (AIEgens) with activated alkynes were synthesized by rational molecular design, and then reacted with silk fibers through facile metal-free click bioconjugation. The resulting conjugates show bright full-color emissions and high stability. A white light-emitting silk was fabricated by simultaneous bioconjugation with red-, green- and blue-emissive AIEgens. The red-emissive AIEgen-functionalized silks were successfully applied for long-term cell tracking and two-photon bioimaging, demonstrating great potential for tissue engineering and bioscaffold monitoring.

We report a supramolecular photo-responsive antibiotic (azobenzene-norfloxacin/αCD). This supramolecule exhibited a higher "on-off" ratio of antibacterial ability than azobenzene-norfloxacin alone under UV irradiation. It offers an approach to efficiently regulate the activity of antibiotics by combining the supramolecular and light-regulating strategies together.

An antibacterial supramolecular polymer is developed that exhibits enhanced antibacterial efficacy and controlled degradability. To this end, a water-soluble bifunctional monomer bearing two naphthalene moieties and a phenylbenzene moiety, as well as a small molecule with antibacterial activity were synthesized. The side-chain antibacterial supramolecular polymer was fabricated through self-sorting of the bifunctional monomer, the small-molecule antibacterial agent, and cucurbit[8]uril. It displayed enhanced antibacterial efficacy against ampicillin-resistant E. coli owing to the local enrichment effect. The controlled degradation of the antibacterial supramolecular polymer could well regulate its antibacterial performance from high to low activity. It is anticipated that this line of research may lead to novel antibacterial supramolecular materials for building degradable antibiotics with enhanced antibacterial efficacy to fight against drug-resistant bacteria.

Patients with osteoporosis are more likely to suffer prosthesis displacement, subsidence or periprosthesis fracture after prosthesis replacement. This is due to excessive osteoclast activity and a lack of bone marrow mesenchymal stem cell (BMSC) integration at the implant-bone interface locally in the setting of osteoporosis. In order to inhibit local excessive bone resorption and promote bone integration, we have constructed a porous titanium/poloxamer 407 hydrogel system loaded with zoledronate (ZOL), a bisphosphonate, to promote osteointegration in a rabbit model of osteoporosis. This composite scaffold (ZOL/gTi) showed good biocompatibility and sustained ZOL release along with the degradation of hydrogel. Not only does this system provide a three-dimensional structural network for BMSC proliferation but also locally released ZOL promotes proliferation and osteogenic differentiation while inhibiting osteoclast differentiation of BMSCs in vitro. After implantation of ZOL/gTi into a distal femoral defect in the rabbits, micro-CT, histological, push-out, as well as genetic and protein analyses revealed significant promotion of osteointegration with the aid of this composite scaffold. Here, we provide an important theoretical basis for the research and development of bioactive implant interfaces for patients with osteogenic defects, such as osteoporosis. Keywords: Bioactive interface, Zoledronate, Osteoporotic microenvironment, Osseointegration

A conjugated polymer-based supramolecular system is designed for discrimination of virus and microbes. The supramolecular system is composed of cationic polythiophene derivative (PT) and barrel-shaped macrocyclic molecular cucurbit[7]uril (CB[7]). Because PT and PT/CB[7] complexes possess different interaction manners toward virus and microbes, the rapid and simple discrimination of virus and microbes was realized through polymer fluorescence intensity change assisting with standard linear discriminant analysis (LDA). The supramolecular strategy would expand the idea of designing biological probes and further promote the extensive application of conjugated polymer materials in biosensor field.

Rapid and effective differentiation and killing of microbial pathogens are major challenges in the diagnosis and treatment of infectious diseases. Here, we report a novel system based on the conjugated polymer poly[(9,9-bis{6′-[N-(triethylene glycol methyl ether)-di(1H-imidazolium)methane]hexyl}-2,7-fluorene)-co-4,7-di-2-thienyl-2,1,3-benzothiadiazole] tetrabromide (PFDBT-BIMEG), which enables efficient microbial pathogen discrimination and killing. The functional side chains of PFDBT-BIMEG enabled both electrostatic and salt bridge interactions with microorganisms. Microorganism binding events caused a change in the aggregation structure of PFDBT-BIMEG, which could be recognized by a change of its fluorescence signal by intramolecular Forster resonance energy transfer (FRET). This sensing strategy allowed rapid and sensitive distinction of microbial pathogens within 15 min. We performed linear discrimination analysis that featured this advance to confirm that the polymer PFDBT-BIMEG could accurately clas...

Infections caused by drug-resistant pathogens have posed a series of public health crises across the world. To address this challenging issue, development of new antibiotics is one of the most effective methods, however it always lags behind the spreading of antibiotic resistance unfortunately. In this work we illustrate an innovative supramolecular strategy to design germicide switch for decelerating the emergence of drug-resistant bacteria. The germicide switches are built up between commercial germicides and cucurbit[7]uril (CB[7]) through host-guest interactions, and their bactericidal activity is switched “off” and “on” reversibly by assembly and dis-assembly processes of germicide/CB[7] complex. Structure-property relation exhibits that the interaction between active sites of germicides and CB[7] plays a decisive role in the antimicrobial activity of these germicide switches. By turning antibacterial activity “on” when needed and turning it “off” when not needed, the germicide switch will not continue to produce pressure on bacteria, thus decelerating the emergence of drug-resistant bacteria. This work offers a proof-of-concept approach to efficiently prevent the emergence of drug-resistant bacteria by controllable and reversible release and concealment of active sites of germicides by supramolecular strategy.

Two β-cyclodextrin-attached cationic ammonium surfactants bearing a dodecyl chain (APDB) and a hexadecyl chain (APCB) were synthesized to reduce the cytotoxicity of cationic surfactants to mammalian cells and endow the surfactants with host–guest recognition sites, and three kinds of guest molecules were utilized to improve the antibacterial ability of APDB and APCB via host–guest interaction by regulating the electrostatic or hydrophobic interaction of APDB or APCB with bacteria. The guest molecules include AD-NH3+ carrying one positive charge, DB with a benzene ring group and a dodecyl chain, and single chain cationic ammonium surfactant DTAB or CTAB. Either AD-NH3+ or DB increases the killing efficacy of APCB against S. aureus at 50 μM from 59% to about 75%, while DTAB or CTAB improves the killing efficacy of APCB to more than 90%. In particular, only a very small amount CTAB can improve the antibacterial activity of APCB to a very high level, but keeps very low cytotoxicity. However, the mixtures of t...

A series of supramolecular photosensitizers were fabricated from porphyrin derivatives (Por) containing quaternary ammonium groups with cucurbit[7]uril (CB[7]) based on host-guest interactions. The antibacterial activity of Por in the dark could be turned off upon binding with CB[7], whereas the antibacterial activity under white-light illumination could be turned on. In addition, its antibacterial efficiency could be greatly enhanced by introducing metal ions. When Pd(II) was introduced into porphyrin, its antibacterial efficiency was enhanced from 40 to 100%. It should be noted that these small molecules showed little to no cytotoxicity toward mammalian cells even at concentrations higher than those under the antibacterial condition studied. This line of research will provide a strategy for germicides consisting of quaternary ammonium groups to fight against bacterial accumulation in the long term and holds huge potential for application in the real world.

Photodynamic therapy (PDT) is a promising method for cancer treatment. Two parameters that influence the efficacy of PDT are the light source and oxygen supply. Herein, we prepared a system for PDT using hemoglobin (Hb)-linked conjugated polymer nanoparticles (CPNs), which can luminesce and supply oxygen. Hb catalyzes the activation of luminol, the conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) nanoparticles can absorb the chemiluminescence of luminol through chemiluminescence resonance energy transfer (CRET) and then sensitize the oxygen supplied by Hb to produce reactive oxygen species that kill cancer cells. This system could be used for the controlled release of an anticancer prodrug. The system does not need an external light source and circumvents the insufficient level molecular oxygen under hypoxia. This work provides a proof-of-concept to explore smart and multifunctional nanoplatforms for phototherapy.

Bacterial infectious disease is a serious public health concern throughout the world. Pathogen drug resistance, arising from both rational use and abuse/misuse of germicides, complicates the situation. Aside from developing novel antibiotics and antimicrobial agents, molecular approaches have become another significant method to overcome the problem of pathogen drug resistance. Established supramolecular systems, the antibiotic properties of which can be switched "on" and "off" through host-guest interactions, show great potential in combating issues regarding antibiotic resistance in the long term, as indicated by several recent studies. In this Concept, recently developed strategies for antibacterial regulation are summarized and further directions for research into antibiotic switches are proposed.

Oxidative stress stimulated by angiotensin II (Ang II) plays an important role in the progression of inflammation and cardiovascular disease. In this work, polythiophene modified with dihydropyridine groups (PTDHP) realized the control of oxidative stress induced by Angiotensin II stimulation in living cells, by inhibiting the activity of NADPH oxidase via DHP groups. Upon light irradiation, the PTDHP could sensitize surrounding oxygen molecules to generate reactive oxygen species (ROS). The generated ROS oxidized the pendant DHP of polythiophene into pyridine group, which inactivated the control ability of DHP to oxidative stress in living cells. Thus, PTDHP can not only control the intracellular oxidative stress effectively and suppress ROS to some degree in dark, but also regulate its anti-oxidative effect under light irradiation.

The employment of physical light sources in clinical photodynamic therapy (PDT) system endows it with a crucial defect in the treatment of deeper tissue lesions due to the limited penetration depth of light in biological tissues. In this work, we constructed for the first time an electric driven luminous system based on electrochemiluminescence (ECL) for killing pathogenic bacteria, where ECL is used for the excitation of photosensitizer instead of a physical light source to produce reactive oxygen species (ROS). We named this new strategy as ECL-therapeutics. The mechanism for the ECL-therapeutics is dependent on the perfect spectral overlap and energy transfer from the ECL generated by luminol to photosensitizer, cationic oligo(p-phenylenevinylene) (OPV), to sensitize the surrounding oxygen molecule into ROS. Furthermore, taking into account the practical application of our ECL-therapeutics, we used flexible hydrogel to replace the liquid system to develop hydrogel antibacterial device. Because the chemical reaction is a slow process in the hydrogel, the luminescence could last for more than 10 min after only electrifying for five seconds. This unique persistent luminescence characteristic with long afterglow life makes them suitable for persistent antibacterial applications. Thus, stretchable and persistent hydrogel devices are designed by integrating stretchable hydrogel, persistent ECL and antibacterial function into hydrogel matrices. This novel strategy avoids the employment of external light source, making it simple, convenient and controllable, which exploits a new field for ECL beyond sensors and also opens up a new model for PDT.

In this work, we explored a supramolecular complex that can be selectively reduced to radical anions in situ by facultative anaerobic bacteria. To this end, a water-soluble bifunctional monomer bearing perylene diimide was synthesized, and its supramolecular complex with cucurbit[7]uril was fabricated on the basis of host-guest complexation, which could be reduced to forming radical anions in the presence of E. coli. It was interestingly found that this supramolecular complex could display different ability of generating radical anions by facultative anaerobic and aerobic bacteria in terms of their various reductive abilities. The selective antibacterial activity of the supramolecular complex could be realized by photothermal performance of radical anions under near-infrared irradiation. It is anticipated that this method may lead to a novel bacteria-responsive photothermal therapy to regulate balance of bacterial flora.

Photodriven hydrogen production has been a good strategy in solar energy utilization. In this work, we use a water-soluble negatively charged polythiophene derivative as photosensitizer to produce hydrogen from aqueous solution containing methyl viologen (MV2+), ethylenediaminetetraacetic acid disodium salt (EDTA), and a colloidal platinum catalyst upon exposure to xenon lamp (>420 nm) or natural sunlight. The supramolecular assembly and dis-assembly processes of MV2+ and cucurbit[8]uril (CB[8]) was further used to reversibly “turn-on” and “turn-off” hydrogen generation of the polymer system. This research offers a proof-of-concept to control hydrogen generation in demand, which is an advantage for hydrogen utilization and storage.

Infections of antibiotic-resistant pathogens have caused a series of public health crises across the world. According to the latest published reports, an antibiotic switch has been recognized as a potential strategy to control antibacterial activity for combating this serious drug resistance. Thus, it is anticipated that more effective antibiotic switches should be obtained by further exploring the developed strategies. Here, we report an improved pretreatment strategy using a surfactant (Triton X-100) for constructing an effective supramolecular antibiotic switch based on a poly(fluorene-co-phenylene) derivative (PFP) and cucurbit[7]uril (CB[7]), which can regulate the aggregation state of polymers before the supramolecular self-assembly process occurs. Triton X-100 can regulate the aggregation states of conjugated polymers, which is used to successfully realize the reversible control of bactericidal activity of PFP in the dark and under white light irradiation by supramolecular assembly/disassembly between PFP and CB[7]. Specialized antibiotic switches are significantly important to fight pathogenic infections and solve the drug resistance crisis in the future.

One of the goals of bone tissue engineering is to mimic native ECM in architecture and function, creating scaffolds with excellent biocompatibility, osteoinductive ability and mechanical properties. The aim of this study was to fabricate nanofibrous matrices by electrospinning a blend of poly (L-lactic-co-glycolic acid) (PLGA), hydroxyapatite (HA), and grapheme oxide (GO) as a favourable platform for bone tissue engineering. The morphology, biocompatibility, mechanical properties, and biological activity of all nanofibrous matrices were compared. The data indicate that the hydrophilicity and protein adsorption rate of the fabricated matrices were significantly increased by blending with a small amount of HA and GO. Furthermore, GO significantly boosted the tensile strength of the nanofibrous matrices, and the PLGA/GO/HA nanofibrous matrices can serve as mechanically stable scaffolds for cell growth. For further test in vitro, MC3T3-E1 cells were cultured on the PLGA/HA/GO nanofbrous matrices to observe various cellular activities and cell mineralization. The results indicated that the PLGA/GO/HA nanofibrous matrices significantly enhanced adhesion, and proliferation in MCET3-E1 cells and functionally promoted alkaline phosphatase (ALP) activity, the osteogenesis-related gene expression and mineral deposition. Therefore, the PLGA/HA/GO composite nanofibres are excellent and versatile scaffolds for applications in bone tissue regeneration.

Cationic poly(fluorene-co-phenylene) derivative (PFP-NMe3+) forms a supramolecular complex with cucurbit[7]uril (CB[7]), which could be reversibly disassembled by amantadine (AD) to release PFP-NMe3+ due to the formation of more stable CB[7]/AD complex. The cationic PFP-NMe3+ is an amphiphilic structure and could bind to negatively charged membrane of pathogen by multivalent interactions. Upon the formation of PFP-NMe3+/CB[7] complex, the CB[7] could bury the side-chain alkyl groups and decreases the hydrophobic interactions of PFP-NMe3+ on the surface of pathogens; thus, PFP-NMe3+ exhibits different interaction modes with pathogens before and after assembly with CB[7]. The PFP-NMe3+/CB[7] supramolecular complex could be explored as optical sensor for simple, rapid, and in situ detection and discrimination of multiple pathogens by taking advantage of optical signal changes of PFP-NMe3+/CB[7] complex before and after disassembly by AD on the pathogen surfaces. The new sensor can realize in situ detection a...

Herein, a simple, effective, and general strategy is demonstrated to obtain a water-soluble and nontoxic cellulose-based photosensitizer (CPS) with enhanced photodynamic antibacterial activity through introducing protoporphyrin IX (PpIX) and quaternary ammonium salt (QAS) groups onto the cellulose backbone. The synergistic effect of the anchoring and diluting effect of the cellulose backbone and the electrostatic repulsion between QAS groups effectively inhibit the π-π stacking of PpIX groups, thus the as-prepared CPS exhibits markedly enhanced reactive oxygen species (ROS) yield. Meanwhile, the positively charged QAS groups endow the CPS with water-solubility and a strong attractive force to bacteria. As a result, the CPS can rapidly and efficiently kill drug-resistant bacteria strains, including E. coli and S. aureus, with a low light dose (2.4 J cm-2 ) and low concentration of PpIX groups (0.35 × 10-6 m). Benefiting from the excellent processability and formability, the CPS is readily applied as a sunlight-driven wearable and robust antibacterial coating by a spray coating and later crosslinking procedure.

Quantitative analysis of interactions between small molecules and proteins is a central challenge in chemical genetics, molecular diagnostics and drug developments. Here, we developed a RNA transcription nanomachine by assembling T7 RNA polymerase on a small molecule-labeled DNA heteroduplex. The nanomachine, of which the RNA transcription activity can be quantitatively inhibited by protein binding, showed a great potential for small molecule-protein interaction assay. This finding enabled us to develop a novel homogeneous label-free strategy for assays of interactions between small molecules and their protein receptors. Three small molecule compounds and their protein receptors have been used to demonstrate the developed strategy. The results revealed that the protein-small molecule interaction assay strategy shows dynamic responses in the concentration range from 0.5 to 64 nM with a detection limit of 0.2 nM. Due to its label-free, homogeneous, and fluorescence-based detection format, besides its desirable sensitivity this technique could be greatly robust, cost-efficient and readily automated, implying that the developed small molecule-protein interaction assay strategy might create a new methodology for developing intrinsically robust, sensitive and selective platforms for homogeneous protein detection.

Antibiotic-resistant bacteria have emerged as a severe threat to human health. As effective antibacterial therapies, supramolecular materials display unprecedented advantages because of the flexible and tunable nature of their noncovalent interactions with biomolecules and the ability to incorporate various active agents in their platforms. Herein, supramolecular antibacterial materials are discussed using a format that focuses on their fundamental active elements and on recent advances including material selection, fabrication methods, structural characterization, and activity performance.

The self-assembly of short peptide offers versatile processes for adjusting the ordered stacking of organic functional materials to enhance photoinduced electron transfer. Herein, this study presents the first demonstration of the use of Aβ16–22 peptide to prepare polythiophene/Aβ16–22 assemblies for a photocatalytic water splitting system. Isothermal titration microcalorimetry results show that the driving forces for polythiophene/Aβ16–22 assembly formation are electrostatic interactions, as well as hydrogen bonds and hydrophobic interactions. The assemblies accelerate the photoinduced electrons transfer from polythiophene upon light excitation and eventually enhance the hydrogen evolution. This work opens a new way into the development of biohybrid materials as novel photocatalytic water splitting platform for hydrogen evolution.