Search

Fluorescent polymers are suffering from low electroluminescence efficiency because triplet excitons formed by electrical excitation are wasted through nonradiative pathways. Here we demonstrate the design of hyperfluorescent polymers by employing through-space charge transfer (TSCT) polystyrenes as sensitizers for triplet exciton utilization and classic fluorescent chromophores as emitters for light emission. The TSCT polystyrene sensitizers not only have high reverse intersystem crossing rates for rapid conversion of triplet excitons into singlet ones, but also possess tunable emission bands to overlap the absorption spectra of fluorescent emitters with different bandgaps, allowing efficient energy transfer from the sensitizers to emitters. The resultant hyperfluorescent polymers exhibit full-color electroluminescence with peaks expanding from 466 to 640 nm, and maximum external quantum efficiencies of 10.3–19.2%, much higher than those of control fluorescent polymers (2.0–3.6%). These findings shed light on the potential of hyperfluorescent polymers in developing high-efficiency solution-processed organic light-emitting diodes and provide new insights to overcome the electroluminescence efficiency limitation for fluorescent polymers., Hyperfluorescent polymers with high efficiency and full-color electroluminescence are developed by using through-space charge transfer polystyrenes as sensitizers for exciton utilization and fluorescent chromophores as emitters for light emission.

Developing controlled drug-release systems is imperative and valuable for increasing the therapeutic index. Herein, we synthesized hypoxia-responsive PEGylated (PEG = poly(ethylene glycol)) paclitaxel prodrugs by utilizing azobenzene (Azo) as a cleavable linker. The as-fabricated prodrugs could self-assemble into stable nanoparticles (PAP NPs) with high drug content ranging from 26 to 44 wt %. The Azo group in PAP NPs could be cleaved at the tumorous hypoxia microenvironment and promoted the release of paclitaxel for exerting cytotoxicity toward cancer cells. In addition, comparative researches revealed that the PAP NPs with the shorter methoxy-PEG chain (molecular weight = 750) possessed enhanced tumor suppression efficacy and alleviated off-target toxicity. Our work demonstrates a promising tactic to develop smart and simple nanomaterials for disease treatment.

π-Stacked dendrimers consisting of cofacially aligned donors and acceptors are developed by introducing three dendritic teracridan donors with orthogonal configuration and three triazine acceptors in periphery of hexaphenylbenzene skeleton. The dendritic structure and orthogonal configuration of teracridan not only make their outer acridan segments approaching to acceptor in close distance, but also fix donor and acceptor in face-to-face alignment, leading to through-space charge transfer emission with thermally activated delayed fluorescence (TADF) effect. By regulating charge transfer strength via substituent effect of acceptor, emission color of the dendrimers can be tuned from blue to yellow/red region. Solution-processed two-color white organic light-emitting diodes (OLEDs) based on blue and yellow π-stacked donor-acceptor dendrimers exhibit the maximum external quantum efficiency of 20.6 % and maximum power efficiency of 58.9 lm W-1 , representing the state-of-the-art efficiency for all-TADF white OLEDs by solution process.

Hollow vesicles self-assembled from amphiphilic copolymers are of great interest in biomedicine field as drug and protein carriers. Efficient preparation of polymeric vesicles with high stability in vivo is highly desirable. Herein, a novel cooperative self-assembly of two graft copolymers (GCPs) with reversed hydrophilic–hydrophobic segments is investigated to achieve morphology control for biomedical application. Interestingly, nanosized vesicles are obtained for the binary system with relatively high hydrophilic fraction (fhydrophilic, ∼60%), contrary to what is found in its single-component counterpart. The cooperative self-assembly endowed the hybrid vesicles with excellent resistance to protein adsorption, prolonged blood circulation time, as well as low leakage of hydrophilic drugs/proteins. Furthermore, the biological activity of the protein is well preserved inside the cooperative vesicles, making it a promising candidate as the protein carrier.

Covalent organic frameworks (COFs) have shown great potential in catalysis and the biomedical fields, but monodisperse COFs with tunable sizes are hard to obtain. Herein, we successfully developed a series of COFs based on electron donor-acceptor strategy in mild conditions. The synthetic COFs exhibit excellent colloidal stability with uniform spherical morphology. The sizes can be flexibly adjusted by the amount of catalyst, and the absorption spectra also vary with the sizes. By changing the electron-donating ability of the monomers, the corresponding COFs possess a wide range of absorption spectra, which can be even extended to the second near-infrared biowindow. The obtained COFs possess potent photothermal activity under laser irradiation, and could inhibit the growth of tumors effectively. This work provides a strategy for the synthesis of monodisperse COFs with variable absorption for their potential applications.

Boron (B)- and sulfur (S)-doped polycyclic aromatic hydrocarbons (PAHs) are developed as a novel kind of multiple resonance emitters for ultrapure blue thermally activated delayed fluorescence (TADF) polymers with narrowband electroluminescence. The combination of electron-deficient B atom and electron-rich S atom in PAH can form an intramolecular push-pull electronic system in a rigid aromatic framework, leading to reduced singlet-triplet energy splitting and limited structure relaxation of excited states. The critical roles of S atom in determining emission properties with respect to the oxygen analogues are in two aspects: (i) reducing energy bandgap to shift emission from human-eye-insensitive ultraviolet zone to blue region, and (ii) promoting reverse intersystem crossing process by heavy-atom effect to activate TADF effect. The resulting polymer containing B,S-doped PAH as emitter and acridan as host exhibits efficient blue electroluminescence at 458 nm with small full-width at half-maximum of 31 nm, representing the first example for ultrapure TADF polymer with narrowband electroluminescence.

Supramolecular aggregation of fluorophores will result in a variable absorption spectrum, which is beneficial for tuning the photophysical properties and improving their functionalities. Herein, ordered aggregates of liposoluble porphyrin molecules are obtained from 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP). The influences of the molecular structures, solvents and polymer surfactants have been investigated, and then tetrahydrofuran and pluronic F-127 are screened out to be the optimal candidates for forming ordered aggregates of TAPP. The as-prepared aggregates of TAPP (TAPP-O NPs) exhibit a red-shifted absorption spectrum of 50 nm, enhanced absorbance in the near infrared region and improved photothermal activity. Particularly, the good phototherapeutic effects of TAPP-O NPs highlight the potential of aggregated organic materials for biomedical applications.

Because of the high expression of glutathione (GSH) and reactive oxygen species (ROS) in cancer cells, nanoparticles formed by various redox-responsive linkers have been widely developed. However, ...

The innate hypoxic microenvironment of most solid tumors has a major influence on tumor growth, invasiveness, and distant metastasis. Here, a hypoxia-activated self-immolative prodrug of paclitaxel (PTX2 -Azo) was synthesized and encapsulated by a peptide copolymer decorated with the photosensitizer chlorin e6 (Ce6) to prepare light-boosted PTX nanoparticle (Ce6/PTX2 -Azo NP). In this nanoparticle, PTX2 -Azo prevents premature drug leakage and realizes specific release in hypoxic tumor microenvironment and the photosensitizer Ce6 not only efficiently generates singlet oxygen under light irradiation but also acts as a positive amplifier to promote the release of PTX. The combination of photodynamic therapy (PDT) and chemotherapy results in excellent antitumor efficacy, demonstrating the great potential for synergistic cancer therapy.

Responsive drug delivery systems possess great potential in disease diagnosis and treatment. Herein, we develop an activatable prodrug and fluorescence imaging material by engineering the endogenous NAD(P)H:quinone oxidoreductase-1 (NQO1) responsive linker. The as-prepared nanomaterials possess the NQO1-switched drug release and fluorescence enablement, which realizes the tumor-specific chemotherapy and imaging in living mice. The enzyme-sensitive prodrug nanoparticles exhibit selectively potent anticancer performance to NQO1-positive cancer and ignorable off-target toxicity. This work provides an alternative strategy for constructing smart prodrug nanoplatforms with precision, selectivity, and practicability for advanced cancer imaging and therapy.

Three kinds of through-space charge transfer (TSCT) blue polymers containing non-conjugated polystyrene backbone together with spatially-separated acridan donor and oxygen-bridged triphenylboron acceptors having different substituents of tert -butyl, hydrogen and fluorine are designed and synthesized. The designed TSCT blue polymers possess photoluminescence quantum yields up to 70% in solid-state film, single-triplet energy splitting below 0.1 eV, and typical thermally activated delayed fluorescence (TADF) effect. Meanwhile, the resulting polymers exhibit aggregation-induced emission (AIE) effect with emission intensity increased by up to ∼27 folds from solution to aggregation state. By changing the substituent of acceptors to tune the charge transfer strength, blue emission with peaks from 444 to 480 nm can be realized for the resulting polymers. Solution-processed organic light-emitting diodes based on the polymers exhibit excellent device performance with Commission Internationale de L’Eclairage (CIE) coordinates of (0.16, 0.27), together with the maximum luminous efficiency of 30.7 cd A−1 and maximum external quantum efficiency of 15.0%, which is the best device efficiency for blue TADF polymers.

The current clinical performance of chemotherapy is far from satisfactory, greatly limited by insufficient delivery efficacy and serious systemic side effects. Dimeric prodrug systems are emerging as valuable strategies for boosting the antitumor outcome. Here, dimeric paclitaxel prodrugs were synthesized with different bridged linkers, and the formed prodrug nanoparticles possessed excellent colloidal stability and ultrahigh drug content. The diselenide bond containing paclitaxel prodrugs could respond to a redox-heterogeneous intracellular microenvironment for on-demand drug release and subsequently show a selective cytotoxicity toward tumor cells against normal cells. Furthermore, the optimal carrier materials were screened out according to their contribution on stability, endocytosis, cytotoxicity, biodistribution, and antitumor efficacy. Compared with DSPE-PEG, human serum albumin, and Fe-tannic acid-based complex, F127 anchored dimeric paclitaxel nanoformulations exhibited preferential tumor accumulation and potent anticancer effect. Our present work provides deep insight into the development of advanced nanoformulations with comprehensive advantages for enhancing cancer therapy.

Through-space charge transfer dendrimers consisting of dendritic triacridan donors and oxygen-bridged triarylboron acceptors are demonstrated to exhibit deep-blue thermally activated delayed fluorescence with the state-of-the-art external quantum efficiency of 14.6% for electroluminescence by a solution process.

Through-space charge transfer polymers (TSCT polymers) that contain a non-conjugated polystyrene backbone and spatially separated donor and acceptor units for solution-processed OLEDs with full-color and white emission is reported. By tuning the charge transfer strength between donor and acceptors with different electron-accepting ability, emission color spanning from deep blue to red can be achieved. By incorporating two kinds of donor/acceptor pairs in one polymer to create duplex through-space charge-transfer channels, blue and yellow emission can be simultaneously obtained to realize white electroluminescence from a single polymer. The TSCT polymers exhibit thermally activated delayed fluorescence effect with delayed-component lifetimes in range of 0.36-1.98 μs, and unexpected aggregation-induced emission (emission intensity enhancement of up to 117 from solution to aggregation state).

Polymer light-emitting diodes (PLEDs) based on thermally activated delayed fluorescence (TADF) emitters show great potential in developing high-efficiency solution-processed light-emitting devices ...

Inspired by the clinically approved albumin based PTX formulation (Abraxane) and high-drug-loading dimeric prodrug tactics, herein we report a theranostic “Abraxane-like” prodrug formulation, which is comprised of human serum albumin (HSA), a paclitaxel (PTX) dimer bridged with thioether liner (PTX2-S), and photosensitizer IR780 iodide. Nanoparticles (NPs) with PTX2-S and IR780 as the core and HSA as the stealth shell are formed. Compared with HSA-based PTX clinical formulation (Abraxane), the dimeric molecules not only constitute the bulk structure of the particles, but also act as crossing agent, thus realizing drug loading content increasing from 6.6 wt.% to 48.7 wt.% with high loading efficiency (> 90%) and excellent stability in biological conditions. Importantly, the thioether linkage dually responds to the tumor redox heterogeneity and the NPs gradually releases the parent drug PTX for chemotherapy. Meanwhile, PTX2-S facilitates the encapsulation of IR780 iodide due to their π-π stacking interaction and IR780 iodide generates spatio-temporal hyperthermia under light irradiation to kill cancer cells for photothermal therapy. The described craft integrates the biomimetic trait of HSA, high drug loading, tumor redox heterogeneity-initiated on-demand drug release, and combination therapy into one formulation and the developed nanoparticles are promising for cancer treatment.

Platinum drugs comprise of almost 50% of all currently used anticancer drugs. They are now widely used in the clinical therapy of various solid tumors, including ovarian, head and neck, colorectal, lung cancers, and so forth. However, their extensive systemic toxicity and the drug resistance acquired by cancer cells limit the applications of platinum drugs. Modern nanobiotechnology provides the possibility for targeted delivery of platinum drugs to the tumor site, thereby minimizing toxicity and optimizing the efficacies of the drugs. Numerous drug delivery carriers, such as polymer nanoparticles, solid lipids, and inorganic nanoparticles, have been developed over the years for delivering platinum drugs. Thus, significant improvements have been made in this field, especially for polymer-based platinum drug delivery systems. In the past five years, particularly interesting studies have been done regarding polymer-based carriers for platinum(IV) drugs, which are chemically inert but can be activated either by intracellular glutathione (GSH) and ascorbic acid (chemically reductive platinum(IV) drugs) or by ultraviolet (UV)/green light (photosensitive platinum(IV) drugs). This review presents a comprehensive overview on the development of various types of polymer-based platinum drug delivery systems. It spans both single-drug carriers and carriers that are combined with other imaging agents, drug sensitizers, and anticancer drugs. Their fabrication methods, mechanisms of action, their applications in cancer therapy, as well as the prospect of their development in the future are also predicted.

A novel biodegradable conducting polymer, PLA-b-AP-b-PLA (PAP) triblock copolymer of poly ( l -lactide) (PLA) and aniline pentamer (AP) with electroactivity and biodegradability, was synthesized and its potential application in cardiac tissue engineering was studied. The PAP copolymer presented better biocompatibility compared to PANi and PLA because of promoted cell adhesion and spreading of rat cardiac myoblasts (H9c2 cell line) on PAP/PLA thin film. After pulse electrical stimulation (5 V, 1 Hz, 500 ms) for 6 days, the proliferation ratio, and intracellular calcium concentration of H9c2 cells on PAP/PLA were improved significantly. Meanwhile, cell morphology changed by varying the pulse electrical signals. Especially, the oriented pseudopodia-like structure was observed from H9c2 cells on PAP/PLA after electrical stimulation. It is regarded that the novel conducting copolymer could enhance electronic signals transferring between cells because of its special electrochemical properties, which may result in the differentiation of cardiac myoblasts.

The human intestine contains thousands of bacterial species essential for optimal health. Aside from their pathogenic effects, these bacteria have been associated with the efficacy of various treatments of diseases. Due to their impact on many human diseases, intestinal bacteria are receiving increasing research attention, and recent studies on intestinal bacteria and their effects on treatments has yielded valuable results. Particularly, intestinal bacteria can affect responses to numerous forms of immunotherapy, especially cancer therapy. With the development of precision medicine, understanding the factors that influence intestinal bacteria and how they can be regulated to enhance immunotherapy effects will improve the application prospects of intestinal bacteria therapy. Further, biomaterials employed for the convenient and efficient delivery of intestinal bacteria to the body have also become a research hotspot. In this review, we discuss the recent findings on the regulatory role of intestinal bacteria in immunotherapy, focusing on immune cells they regulate. We also summarize biomaterials used for their delivery.

Near-infrared (NIR) imaging and photothermal therapy (PTT) based on the multifunctional cyanine dyes has shown great promise for cancer therapy. However, most of the PTT agents are often limited by low drug loading, short circulation time, and low biocompatibility. Herein, we developed cyanine-curcumin assembling nanoparticles (CCNPs) via a single-step reprecipitation method. IR-780-C4 (Cyc4) was employed as a photothermal and NIR imaging agent. Self-assembly of Cyc4 and curcumin in aqueous solution could be performed in the absence of surfactants or adjuvants, which is a simple and efficient way to fabricate nanomedicine with high drug loading. Formed CCNPs showed monodispersity, good stability in physiological conditions, and lower cytotoxicity. Moreover, CCNPs possess the high loading (70%) of cyanine dyes and a higher photothermal conversion efficacy than free Cyc4, which contribute to a decrease in the application dosage of cyanine dyes in cancer therapy. Importantly, CCNPs exhibited excellent NIR imaging capacity and photothermal tumor ablation under laser irradiation in vitro and in vivo. This work highlights the potential of using self-assembling of drug molecules to develop functional nanoparticles for drug delivery and cancer therapy.

Through-space charge transfer polynorbornenes with fixed and controllable spatial alignment of donor and acceptor in edge-to-face/face-to-face stacking patterns are developed for achieving high-efficiency blue thermally activated delayed fluorescence (TADF). The alignment is realized by using the cis, exo-configuration of norbornene to confine donor and acceptor in close proximity, and utilizing orthogonal and dendritic structures of donors to provide either perpendicular or parallel stacking motif relative to acceptors. Compared to edge-to-face counterparts, polynorbornenes with face-to-face aligned donor and acceptor exhibit much larger oscillator strength and higher photoluminescence quantum yield. The resulting polymers exhibit deep blue (422 nm) to sky blue (482 nm) emission and TADF effect with reverse intersystem crossing rates of 0.4-5.9×106 s-1 , giving the maximum external quantum efficiency of 18.8 % for non-doped blue organic light-emitting diodes by solution process.

Combination therapy based on polymer–drug conjugates is one of the exciting developments in polymeric drug delivery systems. A single polymer carrier with two or more drugs attached is advantageous because it provides a platform for synergistic agent action. To expand the concept of combination therapy using a single polymer–drug conjugate, we report a polymer–(multifunctional single-drug) conjugate strategy, in which three different drugs (platinum, azidyl radical and DMC) and two different types of therapies are rationally integrated and then conjugated to an amphiphilic block copolymer. When this polymer–(multifunctional single-drug) conjugate is internalized by cancer cells via endocytosis, the three integrated drugs are expected to be activated and execute therapeutic functions in a sequential fashion under extracellular (UVA irradiation) and intracellular (endosomes/lysosomes) environments to amplify the signals of cancer treatment, especially in cisplatin-resistant cancer cells.

A multifunctional hybrid platinum(IV) drug which has both DCA and Pt in one molecule was synthesized and tethered to polymers to further self-assemble into micelles. This micelle-mediated delivery of platinum(IV) prodrug aims to target both nuclear DNA and mitochondria.

Anticancer drugs of gemcitabine and oxaliplatin combined in a clinic regimen (GEMOX regimen) were co-loaded to a biodegradable polymer platform for drug delivery.

Camplatin, a prodrug formed via coining camphoric anhydride and cisplatin, was delivered in biodegradable nanoparticles. This camphoric acid and cisplatin co-delivery system exhibited enhanced anticancer activity compared to cisplatin and has successfully overcome cisplatin drug resistance.

Injectable and biodegradable supramolecular hydrogels were prepared by nucleobase (adenine/thymine)-terminated poly(ethylene oxide)s (A-PEG-A/T-PEG-T) and α-cyclodextrin (α-CD). The supramolecular hydrogels were thoroughly characterized by WXRD, rheometer, and SEM. The gelation time depended on the molecular weight of PEG and the concentration of polymer precursors. The rheological studies showed enhanced elastic modulus (G′) of hydrogels, because of the hydrogen-bonding between A and T acting as additional network junctions. In vitro evaluation showed that the supramolecular hydrogels have acceptable biocompatibility, and are suitable for sustained and controlled release of loaded antitumor drugs. Gel formation was also confirmed when the supramolecular hydrogels were subcutaneously injected into rats. In addition, in vivo experiments employing U14 cancer cell xenograft-bearing mice showed that the intratumoral injection of a DOX-loaded A-PEG-A/T-PEG-T/α-CD gel inhibited tumor growth more effectively than that of free DOX, DOX-loaded PEG/α-CD gel, saline or gel alone. Hence, such a simple and convenient anti-cancer drug delivery system of a A-PEG-A/T-PEG-T/α-CD supramolecular hydrogel would be a promising candidate for many biomedical applications, especially in the area of the chemotherapy of solid tumors.

A biodegradable triblock copolymer, poly(ethylene oxide)-block-poly(allyl glycidyl ether)-block-poly(DL-lactide) (mPEG-b-PAGE-b-PLA), with allyl groups on its middle block was designed and synthesized through anionic polymerization of allyl glycidyl ether (AGE) with PEG monomethyl ether sodium salt as the macroinitiator and subsequent ring-opening polymerization of DL-lactide. Luteinizing hormone-releasing hormone (LHRH) was conjugated to the PAGE block through a linkage of –SCH2CH2C(O)NH– between the allyl and LHRH residues. The LHRH content in the conjugate was ca. 25 wt%. Owing to the amphiphilic nature of the conjugate, it was self-assembled into micelles of 15–40 nm in diameter and with the LHRH moieties in the hydrophilic corona of the micelles. Cellular uptake experiments were carried out using flow cytometry and confocal laser scanning microscopy (CLSM) with HeLa cells as LHRH-receptor overexpressing cells and HepG-2 cells as normal cells. HeLa cells displayed more cellular uptake of the LHRH-micelles than the normal cells. In vivo biodistribution of the LHRH-containing micelles and LHRH-free micelles was studied using a CRI Maestro™ imaging system. Preferred accumulation in tumor sites of LHRH-containing micelles was observed at 24 hours post injection. Therefore, LHRH-conjugated amphiphilic copolymers might be used as a potential drug delivery system for the treatment of LHRH receptor overexpressing carcinoma.

Carbon dots (CDs) are emerging as powerful nanoprobes for multiple-model bioimaging. Nowadays, orthotopic xenograft models attract increasing attention because of their superiorities of duplicating the tumor microenvironment. However, compared with the extensive study of subcutaneous xenograft tumors, less attention has been paid to CDs for in vivo orthotopic tumor imaging. Furthermore, it is very desirable for a nanoprobe to achieve preferential accumulation at the tumor site and efficient renal clearance. In this work, a novel kind of Hafnium-doped CDs (HfCDs) were successfully prepared via a simple one-pot pyrolysis method. The significant advantages including robust stability, good biocompatibility, excellent water solubility, remarkable computed tomography (CT) contrast performance and preferential tumor accumulation capability endow HfCDs with particular functions of CT/fluorescence imaging of orthotopic liver cancer initially. More importantly, HfCDs could locate at the tumor site and achieve the rapid imaging within 1 min. The findings of the current study represent a facile and universal approach to fabricate outstanding renal clearable multimodal imaging nanoprobes with great potential for clinical diagnosis.

We report the design, synthesis and electroluminescent properties of three kinds of through-space charge transfer (TSCT) polymers consisting of non-conjugated polystyrene backbone, acridan donor and triarylboron acceptors having different substituents such as hydrogen (H), fluorine (F), and trifluoromethyl (CF3). Owing to the weak electron interaction between acridan donor and triarylboron acceptor through non-conjugated connection, blue emission with peaks in range of 429 nm to 483 nm can be achieved for the polymers in solid-state film, accompanied with photoluminescence quantum yields of 26–53%. The resulting TSCT polymers exhibit small ∆EST values below 0.1 eV owing to the separated HOMO and LUMO distributions, showing thermally activated delayed fluorescence with lifetimes in range of 0.19–0.98 μs. Meanwhile, the polymers show aggregation-induced emission (AIE) effect with the emission intensity increased by up to ~33 folds from solution to aggregation state. Solution-processed organic light-emitting diodes based on the polymers containing trifluoromethyl substituent exhibit promising electroluminescent performance with maximum luminous efficiency of 20.1 cd A-1 and maximum external quantum efficiency of 7.0%, indicating that they are good candidates for development of luminescent polymers.

Protein crosslinked nanogels which combine the merits of nanogels and the specific biological activity from protein have emerged as fascinating protein delivery systems. However, the fragility and low density of reactive group in proteins, especially low electric density of neutral proteins seriously limited the fabrication of protein crosslinked nanogels without affecting their bioactivities. Here, we demonstrated a facile ion-assisted method to fabricate neutral protein crosslinked nanogels. Oxidized sodium alginate (OSA) with aldehyde groups and low viscosity was successfully synthesized, which could reversibly form nanogels via addition and removal of divalent cation. Subsequently, hemoglobin and myoglobin were used as representative neutral proteins to fabricate stable protein crosslinked OSA nanogels under the assist of divalent cation followed by in situ Schiff base formation between OSA and proteins. The mild fabrication condition guaranteed the structural integrity and bioactivity of proteins in the obtained protein crosslinked nanogels. This ion-assisted method was expected to bring a new opportunity for fabricating versatile functional biohybrid nanogels systems.

Biomimetic approach offers numerous opportunities to design therapeutic platforms with enhanced antitumor performance and biocompatibility. Herein we report red blood cell membrane-camouflaged nanoparticles (RBC(M(TPC-PTX))) for synergistic chemo- and photodynamic therapy (PDT). Specifically, the inner core is mainly constructed by reactive oxygen species (ROS)-responsive PTX dimer (PTX2-TK) and photosensitizer 5,10,15,20-tetraphenylchlorin (TPC). In vitro experiments show that the prepared RBC(M(TPC-PTX)) is readily taken up into endosomes. Under appropriate light irradiation, the TPC can generate ROS, not only for PDT but also for triggering PTX2-TK cleavage and on-demand PTX release for chemotherapy. In vivo results show that the coating of RBC membrane prolongs blood circulation and improves tumor accumulation. The combination of chemo- and photodynamic therapy enhances anticancer therapeutic activity, and light-triggered drug release reduces systematic toxicity. All these characteristics render the d...

The application of the biphasic release profile furnished by electrospun polyblend nanofibers for local cancer treatment was investigated. By adjusting the weight ratio of the hydrophilic polymer (poly(ethylene oxide), PEO) and hydrophobic polymer (poly(l-lactide), PLA), PEO10-PLA90 fibers with typical biphasic release kinetics were successfully prepared. Due to their unique release profile, PEO10-PLA90 fibers can quickly access the tumor site in vivo at a high drug content within 1 h and keep at a high level for longer than two weeks. In vivo antitumor and safety studies demonstrated that PEO10-PLA90 fibers can achieve optimized local cancer treatment efficacy and avoid undesired adverse reactions. The biphasic drug release profile provided by the polyblend electrospun technology was proven to be a new conception for local chemotherapy.

Single white light-emitting polymers (SWPs) represent a high-fidelity system for generating white light emission from polymers without phase separation compared to polymer blend systems. However, their device performance so far has been limited because of the unwanted hole scattering caused by an energy-level mismatch between emitters and hosts, and the large injection barrier at the polymer/anode interface. Here, we report novel poly(arylene phosphine oxide)-based all-phosphorescent SWPs by using the combination of a high-HOMO-level blue phosphor and high-HOMO-level poly(arylene phosphine oxide) host to achieve a low turn-on voltage of 2.8 V, high external quantum efficiency of 18.0% and remarkable power efficiency of 52.1 lm W−1, which makes them the most efficient SWPs so far. This record power efficiency is realized by using the high-HOMO-level blue phosphor to eliminate the hole scattering effect and by using the high-HOMO-level polymer host to reduce the hole injection barrier. This result represents an important progress in SWPs to achieve efficiency surpassing that of the polymer blends currently used for solution-processed white organic light-emitting diodes (WOLEDs) and even comparable with that of the small molecules used for vacuum-deposited WOLEDs.

The increasing resistance risks of conventional antibiotic abuse and the formed biofilm on the surface of wounds have been demonstrated to be the main problems for bacteria-caused infections and unsuccessful wound healing. Treatment by reactive oxygen species, such as the commercial H2 O2 , is a feasible way to solve those problems, but limits in its lower efficiency. Herein, an ionic covalent-organic framework-based nanozyme (GFeF) with self-promoting antibacterial effect and good biocompatibility has been developed as glucose-triggered cascade catalyst against bacterial wound infection. Besides the efficient conversion of glucose to hydrogen peroxide, the produced gluconic acid by loading glucose oxidase can supply a compatible catalytic environment to substantially improve the peroxidase activity for generating more toxic hydroxyl radicals. Meanwhile, the adhesion between the positively charged GFeF and the bacterial membrane can greatly enhance the healing effects. This glucose-triggered cascade strategy can reduce the harmful side effects by indirectly producing H2 O2 , potentially used in the wound healing of diabetic patients.

Here, we developed stable supramolecular binary vesicles on the basis of the host-guest interaction between β-cyclodextrins (β-CDs) and paclitaxel (PTX) dimer. The inclusion complexation between PTX dimer and β-CDs in water was studied by proton nuclear magnetic resonance spectroscopy and two-dimensional rotating-frame Overhauser effect spectroscopy. The resulting inclusion complex was amphiphilic and could self-assemble into vesicles with average diameter of 230 nm. The vesicles could evolve to nanoparticles (NPs) by adding competitive binding guest amantadine hydrochloride or by digesting β-CDs through α-amylase. Moreover, this process was reversible, and the NPs could also transform to vesicles by adding enough β-CDs again. The obtained hollow supramolecular vesicles were further explored to load hydrophilic dye indocyanine green molecule or hydrophobic anticancer drug doxorobicin for their controlled release under external stimulus. This work provides a new strategy for the design of supramolecular systems by using prodrug as building blocks.

Nanogels with several special advantages have been widely applied in protein delivery. However, biocompatible and biodegradable nanogels used for hemoglobin (Hb) delivery are far less explored. Herein, we developed a facile method to prepare functionalized dextran nanogels for conjugation of Hb. In situ cross-linked and aldehyde group functionalized nanogels (FNGs) were prepared from dextran-g-succinic anhydride-g-dopamine conjugate (Dex-SA-DA) assembly by simple pH adjustion and oxidization in water. Hb was further conjugated into the swelling FNGs by Schiff base reaction under mild condition. The obtained hemoglobin-loaded nanogels (HbNGs) exhibited high stability, oxygen affinity and good hemo-compatibility, suggesting the potential for oxygen carriers. We expected that the designed functionalized nanogels with high stability and loading capacity could bring a new opportunity for protein delivery.

Polymersomes, the structural analogues of liposomes, are hollow structures enclosed by a bilayer membrane made from amphiphilic copolymers. Polymersomes have been proposed to mimic the structure and properties of cellular membranes and viral capsids. Excellent robustness and stability, chemical versatility for tunable membrane properties and surface functionalization make polymersomes attractive candidates for drug delivery, diagnostic imaging, nanoreactor vessels, and artificial organelles. In further biomimetic strategies, stimuli-responsive polymersomes that can recognize various external physical or internal biological environmental stimuli and conduct "on demand" release in dose-, spatial-, and temporal-controlled fashions have been widely developed. This Perspective focuses on recent advances in stimuli-responsive polymersomes and their potential biomedical applications. Representative examples of each stimulus, the advantages and limitations of different strategies, and the future opportunities and challenges are discussed.

RNAi approaches have been widely combined with platinum-based anticancer agents to elucidate cellular responses and to target gene products that mediate acquired resistance. Recent work has demonstrated that platination of siRNA prior to transfection may negatively influence RNAi efficiency based on the position and sequence of its guanosine nucleosides. Here, we used detailed spectroscopic characterization to demonstrate rapid formation of Pt-guanosine adducts within 30 min after coincubation of oxaliplatin [OxaPt(II)] or cisplatin [CisPt(II)] with either guanosine monophosphate or B-cell lymphoma 2 (BCL-2) siRNA. After 3 h of exposure to these platinum(II) agents,50% of BCL-2 siRNA transcripts were platinated and unable to effectively suppress mRNA levels. Platinum(IV) analogues [OxaPt(IV) or CisPt(IV)] did not form Pt-siRNA adducts but did display decreased in vitro uptake and reduced potency. To overcome these challenges, we utilized biodegradable methoxyl-poly(ethylene glycol)-block-poly(ε-caprolactone)-block-poly(l-lysine) (mPEG-b-PCL-b-PLL) to generate self-assembled micelles that covalently conjugated OxaPt(IV) and/or electrostatically complexed siRNA. We then compared multiple strategies by which to combine BCL-2 siRNA with either OxaPt(II) or OxaPt(IV). Overall, we determined that the concentrations of siRNA (nM) and platinum(II)-based anticancer agents (μM) that are typically used for in vitro experiments led to rapid Pt-siRNA adduct formation and ineffective RNAi. Coincorporation of BCL-2 siRNA and platinum(IV) analogues in a single micelle enabled maximal suppression of BCL-2 mRNA levels (to10% of baseline), augmented the intracellular levels of platinum (by ∼4×) and the numbers of resultant Pt-DNA adducts (by5×), increased the cellular fractions that underwent apoptosis (by ∼4×), and enhanced the in vitro antiproliferative activity of the corresponding platinum(II) agent (by 10-100×, depending on the cancer cell line). When combining RNAi and platinum-based anticancer agents, this generalizable strategy may be adopted to maximize synergy during screening or for therapeutic delivery.

Supramolecular hybrids of carbon dots (CDs) and doxorubicin (Dox) were successfully prepared via π–π stacking and electrostatic interactions. The hybrids were characterized by the changes in size, morphology and zeta potential, and further validated by the absorption and photoluminescence spectra. A binding constant of 63 L g−1 between CDs and Dox was calculated from the Stern–Volmer plot. The hybrids between CDs and Dox (CDs–Dox) showed pH-dependent drug loading and release behaviors in aqueous solution. The poor stability of CDs–Dox in fetal bovine serum (FBS) solution led to the rapid separation of Dox and CDs, facilitating the release of Dox and its entrance into cellular nuclei as revealed by confocal laser scanning microscopy (CLSM). After being coated with polydopamine (CDs–Dox@PDA), the stability of the hybrids in cell culture media was enhanced, as supported by the slow release of Dox in living cells. This work highlights the potential of using CDs to synthesize functional nanoparticles through supramolecular interactions.

Dendron engineering in self-host blue Ir dendrimers is reported to develop power-efficient nondoped electrophosphorescent devices for the first time, which can be operated at low voltage close to the theoretical limit (Eg/e: corresponding to the optical bandgap divided by the electron charge). With increasing dendron's HOMO energy levels from B-POCz to B-CzCz and B-CzTA, effective hole injection is favored to promote exciton formation, resulting in a significant reduction of driving voltage and improvement of power efficiency. Consequently, the nondoped device of B-CzTA achieves extremely low driving voltages of 2.7/3.4/4.4 V and record high power efficiencies of 30.3/24.4/16.3 lm W−1 at 1, 100 and 1000 cd m−2, respectively. We believe that this work will pave the way to the design of novel power-efficient self-host blue phosphorescent dendrimers used for energy-saving displays and solid-state lightings.

Drug-loaded nanocarriers, especially polymeric micelles, have attracted much attention in recent years, but their application is still limited due to their systemic toxicity and unsatisfactory tumor delivery efficiency through intravenous administration. In this study, we demonstrated an implantable prodrug micelle/small drug molecule co-loaded nanofiber strategy for enhanced local cancer treatment. A reduction-responsive Pt(iv) prodrug-backboned micelle, as a prodrug of bioactive Pt(ii), and DCA were co-electrospun into poly(vinyl alcohol) (PVA) nanofibers. The prepared Pt(iv) prodrug-backboned micelle/DCA fibers exerted a synergistic effect on cancer cells. In contrast to systemic administration of chemotherapeutic agents, this implantable device exhibited enhanced anti-cancer efficacy with lower systemic toxicity against advanced cervical cancer in vivo. This work provides a facile, efficient and safe prospect of using a prodrug micelle and small molecular drug co-loaded electrospun device for localized and advanced cancer therapy.

On the basis of different generation carbazole dendrons, a series of self-host yellow Ir dendrimers (Y-G0, Y-G1 and Y-G2) have been successfully synthesized and characterized in detail. It is found that the peripheral dendrons can effectively reduce the intermolecular interactions between emissive Ir cores, as verified by the increased photoluminescence quantum yields and film lifetimes. Among these dendrimers, Y-G2 bearing the second generation dendrons shows the best non-doped device performance, revealing a peak luminous efficiency of 20.2 cd/A. The value is nearly twice that of Y-G0 without any dendrons, which could be further improved to 32.1 cd/A by dispersing Y-G2 into a host matrix. We believe that this work will shed light on the development of highly efficient yellow phosphorescent dendrimers with a self-host strategy.

The discovery and synthesis of theranostic nanomedicines with high loading of imaging and therapeutic agents is challenging. In this work, a polymer assembling strategy was used to make nanoparticles with exceptionally high loading of theranostic agent. As an example, poly(heptamethine) was synthesized via multicomponent Passerini reaction, and then assembled into nanoparticles in the presence of poly(ethylene glycol)2k-block-poly(d,l-lactide)2k (PEG–PLA) with high heptamethine loading (>50%). The formed nanoparticles could be used for bimodal bioimaging and photothermal therapy. The bimodal bioimaging provided complementary message about biodistribution, and photothermal treatment inhibited the growth of cervical carcinoma upon laser irradiation. This assembly of polymers formed by imaging and therapeutic agents opens new possibilities for the construction of multifunctional nanomedicines.