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As a noninvasive therapeutic technique, photodynamic therapy (PDT) has attracted numerous research interests for cancer therapy. Nevertheless, the residual photosensitizers (PSs) still produce reactive oxygen species (ROS) and damage normal cells under sunlight after PDT, which limits their practical application in clinic. Herein, the authors propose a self‐degradable type‐I PS based on conjugated polymer, which is composed of aggregation‐induced emission (AIE) and imidazole units. Due to the effective conjugated skeleton and unique AIE properties, thus‐obtained polymers can effectively generate superoxide radical (O2−•) through the type‐I process under light irradiation, which is ideal for hypoxic tumors treatment. Intriguingly, under light irradiation, O2−• produced by the conjugated polymers can further lead to the self‐degradation of the polymer to form nontoxic micro‐molecules. It not only helps to resolve the potential phototoxicity problems of residual PSs, but also can accelerate the metabolism of the conjugated polymers to avoid the potential biotoxicity of drug accumulation. This work develops a self‐degradable type‐I PS, which can turn off the generation of ROS in time after PDT, providing a novel strategy to balance the PDT effect and postoperative safety. [ABSTRACT FROM AUTHOR]

Highlights • Preparation of biodegradable fluorescent organic nanoparticles. • These biodegradable fluorescent organic nanoparticles show aggregation-induced emission feature. • These AIE-active biodegradable FONs exhibit excellent optical properties. • These AIE-active biodegradable FONs are low toxicity and potential for biological imaging. Abstract Fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) characteristics have emerged as ideal probes in fluorescent imaging for visualization of complex biological processes by taking advantages of excellent optical properties, designability and biocompatibility. Significant progresses in the syntheses of AIE-active FONs open up new possibilities in biological applications, whereas, only limited attention was focused on the fabrication of biodegradable FONs through the ring-opening polymerization (ROP) of AIE-active N-carboxyanhydrides (NCA) monomers. In this work, l -Cysteine (Cys) is functionalized with an AIE dye in the side chain, and then transformed into polymerizable NCA monomer with AIE feature. In the next step, amino-terminated poly(ethylene glycol) (PEG) was directly used to initiate the ROP of AIE-active NCA. The prepared amphiphilic copolymers contain hydrophilic PEG and hydrophobic AIE dye have a tendency to self-assemble into core-shell nanostructure. Results confirmed mPEG 5000 Cys-Phe FONs owned high water dispersibility and excellent optical properties. Besides, biological evaluation results demonstrated that these AIE-active FONs possess good biocompatibility and fluorescent imaging performance. More importantly, the strategy also be extend for the preparation other polypeptides based fluorescent probes with desired structure and functions. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Supramolecular interactions between individual molecules are universal forces in living organisms and have been extensively investigated and utilized for fabrication of multifunctional materials over the past few decades. In this work, we reported a rather facile strategy to fabricate the fluorescent organic nanoparticles (FONs) with red fluorescence and aggregation-induced emission (AIE) feature through the supramolecular interactions between the β cyclodextrin (β-CD) and adamantine terminating AIE dye. The structures of prepared Ph-Ad/β-CD FONs were characterized by 1 H nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) spectroscopy. The size and morphology of the final self-assemblies (named as Ph-Ad/β-CD FONs) was characterized by transmission electronic microscopy (TEM). Results demonstrated that these AIE-active FONs can self-assemble into nanoparticles with excellent dispersity and strong fluorescence due to their AIE feature. Biological evaluation demonstrated that Ph-Ad/β-CD FONs has superior biocompatibility and imaging performance. These features endow the Ph-Ad/β-CD FONs good performance in biomedical fields. [ABSTRACT FROM AUTHOR]

The luminescent polymeric nanoparticles (LPNs) with aggregation-induced emission (AIE) properties have emerged as one of the most promising nanoprobes for their unique optical properties. The typical optical feature of AIE-active LPNs should be their obviously enhanced luminescence in aggregation or solid state, which can effectively overcome aggregation caused quenching effects of conventional organic dyes. In this study, we reported for the first time that highly emissive LPNs (named as TPE-E-PAMAM) can be simply fabricated via direct conjugation of tetraphenylethene derivative (TPE-E) with polyamidoamine (PAMAM) dendrimers, which relied on a one-step Michael addition reaction between ene group of TPE-E and amino group of PAMAM dendrimers under rather mild experimental conditions. Because of the strong intermolecular interaction of TPE-E PAMAM copolymers, they can form compact spheres in water and exhibit strong fluorescence in aqueous solution. TPE-E PAMAM LPNs possess high water dispersity, uniform morphology and desirable biocompatibility for biological imaging. More importantly, with large numbers of amino groups on the shell and valid space in the core, PAMAM-TPE-E LPNs have great potential for targeted gene delivery. Taken together, we described a facile one-step covalent strategy for developing AIE-active amphipathic dendrimers, which showed great potential for biomedicine applications. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) is an abnormal phenomenon that has sparked great attention for diverse applications in different fields. In particular, the fabrication and biological imaging applications of AIE-active fluorescent organic nanoparticles (FONs) have become a focus in the emerging and promising fields. A large number of AIE-active polymeric nanoprobes have recently been fabricated through different strategies. The advances and progress in this direction have also recently been summarized by some groups. However, the fabrication and biomedical applications of AIE-active FONs based on carbohydrate polymers and AIE-active dyes are quite rare and limited. In this feature article, the recently reported AIE-active FONs with different structures and applications based on AIE-active dyes and carbohydrate polymers are highlighted, and the major current limitations and development tendencies are also discussed. [ABSTRACT FROM AUTHOR]

Fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) property have received increasing attention and possess promising biomedical application potential in the recent years. Many efforts have been devoted to the fabrication methodologies of FPNs and significant advance has been achieved. In this contribution, a novel strategy for the fabrication of AIE-active amphiphilic copolymers is reported for the first time based on the Ce(IV) redox polymerization. As an example, ene group containing AIE-active dye (named as Phe-alc) is directly grafted onto a water soluble polymer polyethylene glycol (PEG) in H2O/THF system under low temperature. Thus-obtained amphiphilic fluorescent polymers will self-assemble into FPNs with ultra-low critical micelle concentration, ultra-brightness, and great water dispersibility. Biological evaluation results suggest that the PEG-poly(Phe-alc) possess excellent biocompatibility and can be used for tracing their behavior in cells using confocal laser scanning microscope. These features make PEG-poly(Phe-alc) FPNs promising candidates for many biomedical applications, such as cell imaging, drug delivery vehicles, and targeted tracing. More importantly, many other functional groups can also be incorporated into these AIE-active FPNs through the redox polymerization. Therefore, the redox polymerization should be a facile and effective strategy for fabrication of AIE-active FPNs. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) dye-based fluorescent glycopolymers nanoparticles (FGNs) are synthesized with abundant carbohydrate groups on the surface for the first time. This is carried out firstly by free radical polymerization between AIE monomer (PhE) and a renewable biobased monomer itaconic anhydride (ITA), then by the ring-opening reaction between ITA and glucosamine hydrochloride, to obtain glycopolymers with plenty of glycosyl groups on them. The resulted amphiphilic glycopolymer is prone to self-assemble into nanoparticles with high water dispersibility due to the surplus carboxyl groups and glycosyl groups covered on the surface, which can also be further functionalized. The obtained nanoparticles demonstrate strong fluorescence emission, owning to the AIE dyes in the core of nanoparticles. Biocompatibility evaluation and cell uptake behavior of the nanoparticles are further investigated to explore their potential biomedical applications; the demonstrated excellent biocompatibility makes them promising for cell imaging. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) dye-based cross-linked fluorescent polymeric nanoparticles (FPNs) are facilely prepared via a two-step polymerization process including emulsion polymerization and subsequent anhydride cross-linking. Then, a variety of characterization methods are carried out to determine the performance of the FPNs, which show high dispersibility and strong fluorescence in an aqueous solution due to the hydrophilic carboxyl groups on the surfaces and the AIE components as the cores. Biocompatibility evaluation and cell imaging results suggest that these FPNs are biocompatible for cell imaging. More importantly, this cross-linking strategy is proven to overcome the issue of critical micelle concentration and opens the opportunity to develop more robust fluorescent bioprobes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cross-linked AIE dye-based fluorescent organic nanoparticles (FONs). [•] Ring-opening polymerization. [•] High-water dispersibility, uniform morphology, and red fluorescence. [•] Excellent biocompatibility. [Copyright &y& Elsevier]

[Display omitted] Fluorescent sensor has demonstrated to be a facile and effective method to detect heavy metal ions owing to its unique characteristics such as simplicity, ease of operation and cost-effectiveness. In this work, a novel fluorescent probe with aggregation-induced emission (AIE) feature that contains an amide ligand base on the tetraphenylethylene (TPE) dye was designed and successfully synthesized. The utilization of the AIE-active fluorescent probe (named as FDPA) for detection of Cu2+ in aqueous solution has also been examined. We demonstrated that the resultant AIE-active molecule displays amphiphilic property and can self-assemble in aqueous solution with remarkable enhancement of fluorescent intensity owing to its AIE feature. The detection limit of probe for Cu2+ determination is 6.11 × 10−9 M and shows excellent selectivity in the presence of competitive ions. This work provides a useful route to overcome the fluorescence quenching of conventional fluorescent probes in aqueous solution and an elegant way to prepare fluorescent probes with better fluorescence properties. [ABSTRACT FROM AUTHOR]

Self-assembly of polymeric materials to form nanoparticles is a particularly promising strategy for various biomedical applications, however, these self-assembling systems often encounter the critical micelle concentration (CMC) issue, as the nanoparticles is usually unstable at low concentration. Therefore, stable cross-linked fluorescent polymeric nanoparticles (FPNs) were covalently constructed from an aggregation induced emission (AIE) dye, itaconic anhydride, poly(ethylene glycol) monomethyl ether methacylate and polyethylenimine. These obtained PhE-ITA-20%(80%) FPNs were fully characterized by a series of techniques including 1 H NMR spectra, UV–vis absorption spectra, fluorescence spectra, FT-IR spectra, transmission electron microscopy, gel permeation chromatography, and dynamic light scattering. Such FPNs emitted intense fluorescence due to the introduction of aggregation induced emission dye. More importantly, the FPNs were found extremely stable in physiological solution even below the CMC owing to their cross-linked architectures. Biocompatibility evaluation and cell uptake behavior of the FPNs were further investigated to explore their potential biomedical applications, the demonstrated excellent biocompatibility made them promising for cell imaging. [ABSTRACT FROM AUTHOR]

The functional materials with aggregation-induced emission (AIE) feature have been extensively explored for biomedical applications, however, the synthesis of AIE-active functional materials with biodegradable potential and controlled drug delivery behavior have been seldom demonstrated. In this work, we reported for the first time that AIE-active fluorescent cyclomatrix polyphosphazene spheres (named as QM-HCCP-PEG) can be facilely fabricated via a one-step nucleophilic substitution to conjugate hexacyclotriphosphazene (HCCP), amino modified polyethylene glycol (PEG-NH 2) and an AIEgen (QM-OH). The resultant QM-HCCP-PEG shows amphiphilicity and can be capable of self-assembling into spheres with high water dispersibility and desirable fluorescence performance. During self-assembly, antitumor drug bortezomib (BTZ) can be encapsulated in the core of QM-HCCP-PEG with a relative high drug loading capacity up to 12.2%. In vitro drug release profile showed that the micelles could successfully release BTZ in physiological solution. Moreover, the QM-HCCP-PEG displayed excellent biological imaging ability for its outstanding AIE feature and BTZ-loaded nanospheres exhibited significant cytotoxicity against MDA-MB-231 cells. Thus, this work provides new perspective for fabrication of AIE-active functional materials via a convenient and highly efficient experimental procedure and the resultant AIE-active functional materials are of great potential as fluorescent probes and drug delivery vehicles. [Display omitted] • One-pot synthesis of AIE-active fluorescent cyclomatrix polyphosphazene spheres. • AIE-active fluorescent cyclomatrix polyphosphazene spheres were used for delivery BTZ. • BTZ shows pH dependent release behavior. • AIE-active fluorescent cyclomatrix polyphosphazene spheres for cell imaging. [ABSTRACT FROM AUTHOR]

Fluorescence imaging and magnetic resonance imaging have been research hotspots for adjuvant therapy and diagnosis. However, traditional fluorescent probes or contrast agents possess insurmountable weaknesses. In this work, we reported the preparation of dual-mode probes based on mesoporous silica nanomaterials (MSNs), which were doped with an aggregation-induced emission (AIE) dye and Gd3+ through a direct sol-gel method. In this system, the obtained materials emitted strong red fluorescence, in which the maximum emission wavelength was located at 669 nm, and could be applied as effective fluorescence probes for fluorescence microscopy imaging. Furthermore, the introduction of Gd3+ made the nanoparticles effective contrast agents when applied in contrast-enhanced magnetic resonance (MR) imaging because they could improve the contrast of MR imaging. The excellent biocompatibility of these nanoparticles, as demonstrated via a typical CCK-8 assay, and their performance in fluorescence cell imaging and MR imaging shows their potential for applications in biomedical imaging. [ABSTRACT FROM AUTHOR]

Abstract Because of its unique optical properties, the aggregation-induced emission (AIE) dye has attracted extensive attention for various applications. Especially, the utilization of AIE-active dyes for fabrication of fluorescent organic nanoparticles (FONs) has attracted the most research interest for biomedical applications. Therefore, the development of novel and effective strategies to design and prepare AIE-active FONs should be of great importance for the biomedical applications of AIE-active FONs. In this report, we reported an ultrafast strategy that based on the one-pot microwave-assisted Biginelli reaction for fabrication of AIE-active poly(AA-AEMA-TPE) copolymers, which use the 2-(methacryloyoxy) ethylacet, acrylic acid (AA) and 4′,4‴-(1,2-diphenylethene-1,2-diyl) bis([1,1′-biphenyl]-4-carbaldehyde) (TPE-CHO) as the substrates. The microwave-assisted Biginelli reaction is simple, efficient and atom-economical and can be accomplished within 3 min. Owing to their amphiphilicity, poly(AA-AEMA-TPE) copolymers will self-assemble into FONs with small size and high water dispersibility. The proton nuclear magnetic resonance (1H NMR) spectroscopy, UV-Vis spectrum and fluorescence spectrometer were used to characterize the resultant copolymers. We demonstrated that poly(AA-AEMA-TPE) FONs possess many excellent properties, such as high water dispersibility, intense fluorescence, obvious AIE feature and favorable biocompatibility. The above results suggest that poly(AA-AEMA-TPE) FONs are of great potential for fluorescent imaging. Moreover, the microwave-assisted Biginelli reaction can occur under a rather benign environment with high efficiency and good substrate adaptability. Therefore, we believe that the method developed in this work could greatly advance the applications of AIE-active functional materials. Graphical abstract Image 1 Highlights • Novel method for fabrication of fluorescent organic nanoparticles with aggregation-induced emission feature. • The method for synthesis of AIE-active FONs is fast and effective. • The microwave-irradiation assisted multicomponent reaction could be complished within 3 min. • The resultant AIE-active poly(AA-AEMA-TPE) FONs are of desirable properties and potentially for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract Over the past several years, the biomedical applications of fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) feature have been extensively explored because the AIE-active FONs could effectively overcome the aggregation caused quenching (ACQ) effect of FONs based on conventional organic dyes. The development of novel methods for synthesis of AIE-active FONs plays a centre role for their biomedical applications. In this work, we reported a facile one-step thiol-ene click reaction for fabrication of AIE-active FONs through conjugation of acrylated PEG and AIE-active tetraphenylethylene (TPE) with two ene bonds using pentaerythritol tetra(3-mercaptopropionate) as the linkage. The successful synthesis of TPE containing AIE-active copolymers was evidenced by various characterization techniques. The particle size and fluorescence properties of the resultant TPE-S-PEG copolymers were evaluated by transmission electronic microscopy and fluorescence spectroscopy. Moreover, the cell viability and cell uptake behavior was also examined to evaluate their potential for biological imaging. We demonstrated that the cross-linked TPE-S-PEG show small size, high water dispersibility, low cytotoxicity and strong fluorescence for tracing. All of these advantages endow the TPE-S-PEG FONs great potential for biological imaging applications. Furthermore, this novel click reaction can take place under mild experimental conditions with high efficiency. It could be also further expanded for preparation of multifunctional AIE-active materials due to the universality of the thiol-ene click reaction and good precursor applicapability. Taken together, we have developed a novel and effective thiol-ene click reaction to fabricate the cross-linked AIE-active FONs, which display excellent physicochemical and biological properties and are promising for biomedical applications. Graphical abstract Unlabelled Image Highlights • Fabrication of PEGylated AIE-active FONs through thiol-ene click reaction • These PEGylated AIE-active FONs possess small size and strong fluorescence. • These PEGylated AIE-active FONs are of high water dispersibility and low toxicity. • These PEGylated AIE-active FONs are promising for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract Aggregation-induced emission (AIE) should be a unique and abnormal fluorescence phenomenon that has attracted increasing research interest over the past decades. Since its discovery by Tang et al., a number of AIE-active molecules with different structure, functional groups and optical properties have been reported. These AIE-active molecules can be further utilized to fabricate various functional materials, which have exhibited great potential for different applications. By taking advantage of this AIE feature (quenching in solution but emission in aggregation state), various bio-/chemosensors have been constructed for detection of relation biological and chemical species. Although some review items on these aspects have been summarized previously, some recent advances and development about targeted biosensor are not included. In this review article, the recent advances and progress in the construction of AIE-active luminogens based fluorescent bio-/chemosensors has been summarized. The challenge and further development of the construction of AIE-active molecules based bio-/chemosensors are also highlighted. Graphical abstract Image 1 Highlights • Design and fabrication of sensors based on AIEgens. • AIEgens could be used for chemosensor. • AIEgens could be used for biomosensor • The utilization of AIEgens for various biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract Fluorescent silica nanoparticles (FSNPs) have attracted great interest for potential applications in biological and biomedical fields because they possess higher fluorescence quantum yield and better fluorescence stability as comparison with small organic fluorescent molecules. The encapsulation of covalent linkage with fluorescent organic dyes or fluorescent metal complexes has demonstrated to be the commonly adopted strategies for fabrication of FSNPs previously. However, it is still challengeable to obtain FSNPs based polymer composites with intensive fluorescence and good water dispersibility through a one-pot surface modification strategy. In this paper, we developed a facile method to fabricate novel FSNPs based polymer composites (PhE@MSNs-PEtOx) through introducing the aggregation-induced emission (AIE) dye (PhE-OH) and poly(2-ethyl-2-oxazoline) (PEtOx) onto mesoporous silica nanoparticles (MSNs) based on cationic ring opening polymerization (CROP). The resulting PhE@MSNs-PEtOx composites possess strong fluorescence emission, excellent hydrophilicity and biocompatibility. These features make the final FSNPs based polymer composites great potential for biomedical applications. Taken together, we have developed for the first time that FSNPs based polymer composites can be facilely prepared through the one-pot introduction of AIE dyes and hydrophilic PEtOx on MSNs. Moreover, the novel FSNPs based composites could also be utilized for other biomedical applications considered their properties. Graphical abstract Unlabelled Image Highlights • Surface modification of AIE-active silica nanoparticles • Surface-initiated cationic ring opening polymerization • Fluorescent nanomaterials with aggregation-induced emission feature • These fluorescent AIE-active silica nanomaterials are of great potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract Amphiphilic copolymers play a paramount role in the fabrication of fluorescent polymeric nanoparticles (FPNs) through the self-assembly procedure. In this work, novel hydrazine hydrate cross-linked amphiphilic poly(PEG‑ co ‑FHMA) copolymers were constructed via reversible addition-fragmentation chain transfer (RAFT) polymerization, containing an aggregation-induced emission (AIE) active hydrophobic moiety and a hydrophilic poly(ethylene glycol) (PEG) group. Different characterization techniques have been employed to confirm their successful synthesis. Due to their amphiphilic property, the resulting poly(PEG‑ co ‑FHMA) copolymers can self-assemble into FPNs in aqueous solution and form poly(PEG‑ co ‑FHMA) FPNs with size ranging from 100 to 200 nm. The investigation of photophysical properties demonstrated poly(PEG‑ co ‑FHMA) FPNs possess strong fluorescence, large Stokes shift, excellent AIE characteristic, low critical micelle concentration and remarkable photostability. Biological assay results suggested that these cross-linked AIE-active FPNs are of low toxicity and excellent cell dyeing performances. All of these features make them promising candidates for biomedical applications. As compared with typical AIE-active FPNs based on the synthetic AIE-active compounds, the novel cross-linked AIE-active FPNs based on the Schiff base is rather simple, good designable and universal. More importantly, this strategy could also be adopted for preparation of a large number of AIE-active FPNs because of the well designability of copolymers and salicylaldehyde derivatives. Thus this work will provide a novel route for preparation of multifunctional AIE-active FPNs in a rather facile manner. Graphical abstract A novel strategy has been developed for the preparation of cross-linked AIE-active fluorescent polymer nanoparticles for biological imaging applications. Unlabelled Image Highlights • Hydrazine hydrate cross-linked fluorescent copolymers • AIE-active fluorescent polymeric nanoprobes • These AIE-active FPNs show excellent properties and low toxicity. • These AIE-active FPNs are of great potential for biomedical applications. [ABSTRACT FROM AUTHOR]

In recent years, florescent polymeric nanoparticles (FPNs) containing aggregation-induced emission (AIE) fluorogens have received great intention for their potential applications in biological imaging and theranostic nanomedicine. Herein, we have developed AIE-active FPNs through a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and post-polymerization modification strategies. The salicylaldehyde (SA) containing zwitterionic copolymers are fabricated via RAFT polymerization and further modified by benzophenone hydrazone (BPH) via Schiff base reaction. The obtained AIE-active amphiphilic copolymers BPH-poly(FHMA- co -MPC) can self-assemble in aqueous solution with the hydrophobic fluorogens aggregating together to form the core and the hydrophilic chains to form the protective shell. BPH-poly(FHMA- co -MPC) and the resulting FPNs are characterized by 1 H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy. Results demonstrate that BPH-poly(FHMA- co -MPC) are successfully synthesized and as-prepared BPH-poly(FHMA- co -MPC) FPNs exhibit desirable morphology and size, good dispersibility, high brightness, remarkable photostability and large Stokes shifts. More importantly, through cytotoxicity test and cell uptake behavior, these BPH-poly(FHMA- co -MPC) FPNs show low toxicity and excellent cell dyeing behavior. Taken together, we have developed a facile and effective method for the fabrication of AIE-active FPNs, which display great potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract Aggregation-induced emission (AIE) should be the most interest fluorescent phenomenon over the past few decades. The luminescence polymeric nanoparticles (LPNs) with AIE characteristic have attracted great research attention for biological imaging and many other biomedical applications owing to their good biocompatibility and negative toxicity. However, the preparation of LPNs with desirable optical properties using traditional organic dyes still remains a great challenge for the aggregation-caused quenching (ACQ) effect and aggregation of hydrophobic dyes in the core of LPNs. In this work, we reported a novel and simple method for fabrication of biodegradable AIE-active LPNs via the combination of condensation and click reactions. For preparation of these AIE-active LPNs, the thiol groups-containing hydrophilic copolymers (PEG-MA) were first synthesized through the condensation reaction between polyethylene glycol and mercaptosuccinic acid. The PEG-MA copolymers were further reacted with AIE dye PhE-OE through a catalyst-free thiol-yne click reaction. These obtained PEG-MA-PhE LPNs were fully characterized by a number of characterization techniques. All the results confirmed that PEG-MA-PhE LPNs possess excellent compatibility, intense red luminescence, great photostability and high water dispersibility. These features make PEG-MA-PhE LPNs promising candidates for various biomedical applications. Graphical abstract A novel catalyst-free thiol-yne click chemistry was developed for the preparation of biodegradable luminescent polymeric nanoparticles with aggregation-induced emission feature. Unlabelled Image Highlights • Catalyst-free thiol-yne click reaction • Aggregation-induced emission luminescent polymeric nanoparticles • The AIE-active LPNs are degradable potential. • The AIE-active LPNs promising for biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescent probes have long been regarded as tools for imaging living organisms with advantages such as high sensitivity, good designability and multifunctional potential. Many fluorescent probes, especially the probes based on aggregation-induced emission (AIE) dyes, have received increasing attention since the AIE phenomenon was discovered. These AIE dye-based fluorescent probes could elegantly overcome the notorious quenching effect caused by aggregation of conventional organic dyes. However, it is still difficult to directly apply these AIE-active dyes for biomedical applications owing to their hydrophobic nature. Therefore, the development of novel and facile strategies to endow them with water dispersibility is of critical importance. In this work, we exploit an efficient and simple strategy to fabricate an AIE dye-based fluorescent copolymer through the combination of reversible addition-fragmentation chain transfer and the Biginelli reaction. Moreover, the copolymer can self-assemble to fluorescent polymeric nanoparticles (FPNs) in water solution. Hydrophilic poly(PEGMA- co -AEMA) was reacted with the AIE-active dye 4′,4‴-(1,2-diphenylethene-1,2-diyl)bis([1,1′-biphenyl]-4-carbaldehyde (CHO-TPE-CHO) to form amphiphilic luminescent polymers using urea as the connection bridge. The successful synthesis of the final products (poly(PEGMA- co -AEMA-TPE) FPNs) was confirmed by various instruments. Furthermore, Transmission electron microscopy (TEM) images manifest that poly(PEGMA- co -AEMA-TPE) copolymers will self-assemble into spherical nanoparticles in aqueous environments with sizes between 100 nm and 200 nm. The cell uptake and bioimaging experiment confirm that poly(PEGMA- co -AEMA-TPE) FPNs have excellent biocompatibility and emit strong green fluorescence in a cellular environment. Thus, poly(PEGMA- co -AEMA-TPE) FPNs are excellent candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) is an abnormal phenomenon, which has been extensively explored for various applications. Taken advantage of the unique AIE feature, a number of luminescent nanoprobes with strong fluorescence intensity could thus be fabricated through different strategies; however, the fabrication of AIE-active carbohydrate polymers is still challenge owing to the poor solubility of carbohydrate polymers in most of organic solvents. In this work, a rather facile strategy has been developed for fabricating AIE-active sodium hyaluronate (Sh) through the formation of dynamic phenyl borate between the phenylboronic acid groups of AIE dye (An-B(OH) 2 )) and Sh in a “one-pot” route. This reaction could occur under low temperature, air atmosphere and in the present water. The physicochemical properties, biocompatibility, biological imaging and drug delivery performance of the final An-Sh fluorescent organic nanoparticles (FNPs) were confirmed by different characterization techniques. Results suggested that An-Sh FNPs possess high water dispersibility, strong fluorescence, and good biocompatibility. These excellent properties make An-Sh FNPs great potential for biological imaging and controlled drug delivery applications. In conclusion, we have developed a facile one-pot strategy for the preparation of AIE-active FNPs through the formation of dynamic bonds in rather mild experimental conditions. The outstanding properties and performance of An-Sh FNPs make them promising candidates for biological imaging and controlled drug delivery applications. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) is a unique fluorescence phenomenon that has attracted great interest for various applications especially for the fabrication of AIE-active polymeric nanoparticles. The AIE-active fluorescent polymeric nanoparticles (FPNs) showed attractive optical properties, which could elegantly overcome the lousy aggregation-caused quenching (ACQ) effect of FPNs based on conventional organic fluorogens. Although great advances and progress have been achieved for the fabrication of AIE-active FPNs, the preparation of AIE-active carbohydrate polymers is still challengeable for the poor solubility of carbohydrate polymers in organic solvents. In this work, we reported the sodium alginate-based fluorescent biopolymers (OSA-PA-PhE) with AIE characteristic could be facilely fabricated via an ultrafast one-pot multicomponent reaction (named as Döbner reaction) with the assistance of microwave irradiation. Among the Döbner reaction system, the oxidized sodium alginate (OSA) and AIE-active dye (named as PhE-NH 2 ) were conjugated using pyruvic acid (PA) as the molecular “bridge”. A number of characterization techniques, such as proton nuclear magnetic resonance ( 1 H NMR), fourier transform infrared (FT-IR) spectroscopy, UV–Vis absorption spectroscopy, fluorescent spectroscopy and transmission electron microscopy (TEM), have been utilized to confirm the successful preparation of OSA-PA-PhE biopolymers. The biological evaluation results confirmed that the OSA-PA-PhE FPNs possessed ultrahigh biocompatibility and desirable imaging properties. Moreover, compared with the previous work about FPNs, this work had at least two obvious advantages, one was the original materials of sodium alginate are resourceful, cheaper, and compatible for human tissue and cells, and another was the novel Döbner reaction is a facile conjugation reaction under mild experimental conditions (e.g. catalyst-free, air atmosphere and in the presence of water). Considered the features of microwave-assisted Döbner reaction and OSA, the OSA-PA-PhE FPNs should be of great potential for different biomedical applications. [ABSTRACT FROM AUTHOR]

Ultrasound as a powerful technique has increasingly been used in both industry and academia in recent years. Herein, an efficient approach to the ultrafast preparation of cross-linked fluorescent copolymers (PEGMA-AEMA-TPE) with aggregation-induced emission (AIE) via an ultrasound-assisted multicomponent reaction (MCR) is described. A number of characterization techniques were carried out to certify the successful preparation of these AIE-active copolymers. Due to the introduction of a hydrophilic PEG fragment and a hydrophobic AIE-active dye, the obtained fluorescent copolymers showed amphiphilic properties and could assemble into organic dyed polymer nanoparticles (ODPNs) with great water dispersibility. The final PEGMA-AEMA-TPE ODPNs demonstrated intense fluorescence, strong photostability, a low critical micelle concentration (CMC) of 0.007 mg mL −1 and high biocompatibility. More importantly, the PEGMA-AEMA-TPE ODPNs show obvious AIE characteristics, which could elegantly overcome the quenching effect caused by the aggregation of ODPNs based on conventional organic dyes. Considered the above results, we believe that these AIE-active ODPNs should be promising candidates for biological imaging and other biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescent polymeric nanoparticles (FPNs) as novel probes have attracted more and more attention for biomedical applications owing to their optical properties and multifunctional potential. However, most of FPNs based on conventional organic fluorogens encounter serious aggregation-caused quenching (ACQ) effect. In this work, to overcome these problems, amphiphilic fluorescent copolymers [Poly(PEGY-PhE)] containing aggregation-induced emission (AIE) fluorogens (AIEgens) have been prepared via a facile amino-yne click polymerization under rather mild experimental conditions (catalyst-free and room temperature). The Poly(PEGY-PhE) copolymers can self-assemble into FPNs and be well dispersed in aqueous solution. Fluorescence spectra demonstrate that Poly(PEGY-PhE) FPNs possess strong red fluorescence, excellent photostability and low critical micelle concentration. The biological assays confirm that these AIE-active Poly(PEGY-PhE) FPNs possess low cytotoxicity towards L929 cells and cell dyeing performance. More importantly, this amino-yne click polymerization provides a simple strategy to prepare robust biocompatible fluorescent nanoparticles for biological imaging because of their high efficiency, mild reaction conditions and simple experimental operation procedure. [ABSTRACT FROM AUTHOR]

Supramolecular polymerization is a novel method for the fabrication of multifunctional polymeric composites that mainly relied on the non-covalent interactions between different components. In this work, a novel and facile strategy has been developed for the construction of fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) characteristic based on the host-guest interaction between β cyclodextrin terminating polyethylene glycol (β-CD-PEG) and adamantine (Ad) containing AIE dye (Ph-Ad). Through the host-guest interaction, the fluorescent amphiphiles can be facilely obtained. The characterization results suggested we have successfully prepared the AIE-active FONs through the supramolecular polymerization. The Ph-Ad/β-CD-PEG FONs possess many advantages such small size, high water dispersibility, desirable fluorescence properties, low cytotoxicity and efficient cell dyeing performance. All of the above results implied that these AIE-active supramolecular assemblies should be promising luminescent probes with great potential for different biomedical applications. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp), as an important biomaterial for the regeneration and reconstruction of bone tissue, has attracted more and more attention of researchers and scientists due to its unique structure and compositions. However, the preparation of fluorescent HAp with controllable morphology has achieved only limited success. In this work, we reported a novel strategy to construct the water dispersible fluorescent HAp nanorods via the combination of ligand exchange and metal-free atom transfer radical polymerization (ATRP). The Br-containing fluorescent HAp nanorods with controllable size and morphology were first prepared through hydrothermal treatment. A multifunctional organic molecule (named as PTH-Br) with aggregation-induced emission feature was immobilized on the surface of hydrophobic HAp nanorods through ligand exchange reaction. The PTH-Br could be used as the initiator and catalyst for surface-initiated metal-free ATRP using poly(ethylene glycol) methacrylate as monomer to obtain hydrophilic fluorescent HAp polymer nanoparticles. This strategy successfully endowed HAp nanorods excellent fluorescence properties and favorable water dispersibility but well preserved their regular morphology. Biological assays demonstrated that the HAp-PTH-poly(PEGMA) nanoparticles exhibited good biocompatibility and efficient cell uptake performance. Taken together, we have developed a rather facile strategy based on the surface ligand exchange reaction and metal-free photoATRP to fabricate fluorescent HAp with controllable size and morphology, high water dispersibility and biological properties. These HAp-PTH-poly(PEGMA) nanoparticles should be novel and promising candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

The fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) feature have recently attracted the most research interest owing to their well designability, outstanding optical properties and great potential for biomedical applications. Therefore, the development of novel strategies that could facilely fabricate AIE-active functional materials with high efficiency should be of great importance for their biomedical applications. In this work, a novel strategy that based on the microwave-assisted multicomponent tandem polymerization (MCP) has been developed to fabricate the biodegradable FONs with AIE feature. The AIE-active dye (NH 2 -PhE-NH 2 ) with two amino groups, hydrophilic dialdehyde-terminating copolymer (PEG-PCL-CHO) and diethyl phosphite were successfully conjugated via a “one-pot” microwave-assisted Kabachnik–Fields (KF) reaction under rather mild conditions (e.g. air atmosphere, catalysts-free and solvent-free) within short reaction time (5 min). The obtained PEG-PCL-PhE FONs were characterized by a series of techniques. Results demonstrated that PEG-PCL-PhE FONs possess great water dispersibility, excellent optical properties as well as low cytotoxicity. Taken together, we developed a novel MCP strategy that based on the microwave-assisted KF reaction to fabricate AIE-active FONs with great physicochemical and biological properties. These AIE-active FONs are of great potential for biological imaging applications. Moreover, this strategy could also be adopted to fabricate many other AIE-active functional materials owing to its simple operation, high efficiency, short reaction time and substrate diversity. [ABSTRACT FROM AUTHOR]

In recent years, the fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature have been extensively exploited in various biomedical fields owing to their advantages, such as low toxicity, biodegradation, excellent biocompatibility, good designability and optical properties. Therefore, development of a facile, efficient and well designable strategy should be of great importance for the biomedical applications of these AIE-active FPNs. In this work, a novel method for the fabrication of AIE-active FPNs has been developed through the self-catalyzed photo-initiated reversible addition fragmentation chain transfer (RAFT) polymerization using an AIE dye containing chain transfer agent (CTA), which could initiate the RAFT polymerization under light irradiation. The results suggested that the final AIE-active FPNs (named as TPE-poly(St-PEGMA)) showed great potential for biomedical applications owing to their optical and biological properties. More importantly, the method described in the work is rather simple and effective and can be further extended to prepare many other different AIE-active FPNs owing to the good monomer adoptability of RAFT polymerization. [ABSTRACT FROM AUTHOR]

The fabrication and biomedical applications of fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature has attracted the most intensive research interest since the first discovery of AIE phenomenon by Tang' group. Although great attention has been devoted to preparation of AIE-active FPNs, an efficient, facile and versatile strategy is still highly desirable to advance their biomedical applications. In this work, a one-pot microwave-assisted multicomponent tandem polymerization was proposed to fabricate AIE-active FPNs based on a microwave-assisted Kabachnik–Fields (KF) reaction, which involves the conjugation of aldehyde group containing polyethylene glycol (CHO-PEG-CHO) and amino-group terminating AIE dye (H 2 N-PhE-NH 2 ) using diethyl phosphate as the lock. The KF reaction can occur under rather facile and mild experimental conditions (e.g. absent of catalyst and solvents, air atmosphere) with the assistance of microwave irradiation in 5 min. The resultant (PEG-DP-PhE) copolymers would self-assemble into FPNs that showed high water dispersibility and enhanced fluorescence intensity. The desirable cytocompatibility and cell uptake efficiency of PEG-DP-PhE FPNs endow their great potential for biomedical applications. Considering the convenience and effectiveness, the method should be promising for fabrication of many AIE-active functional materials with great application potential. [ABSTRACT FROM AUTHOR]

The research in fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) feature shows an upward trend due to their outstanding optical properties and potential biomedical applications. In this work, a novel strategy has been developed for the first time through a catalyst-free azide-alkyne click reaction, which could directly conjugate azide containing polymers (PEGMA-AGE-N 3 ) and alkyne terminating AIE dye (named as PhE-OE) under mild experimental conditions. The final PEGMA-AGE-PhE copolymers containing AIE-active dye could self-assemble into FONs with intense fluorescence owing to their AIE feature. These PEGMA-AGE-PhE FONs were characterized by a series of characterization techniques in details. The cell viability as well as cell uptake behavior of PEGMA-AGE-PhE FONs was also examined to evaluate their potential for biomedical applications. We demonstrated that the catalyst-free azide-alkyne click reaction is effective for fabrication of AIE-active FONs and these AIE-active FONs showed high water dispersity and AIE feature. Moreover, the PEGMA-AGE-PhE FONs also exhibited low cytotoxicity and great potential for biological imaging. Taken together, a facile catalyst-free azide-alkyne click reaction with high efficiency has been developed for the preparation of AIE-active FONs, which showed excellent physicochemical properties for biological imaging applications. [ABSTRACT FROM AUTHOR]

Fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) features have recently emerged as promising fluorescent probes for biomedical applications owing to their excellent optical properties, designability and biocompatibility. Significant progress has been made recently for synthesis and biomedical applications of these AIE-active FONs. However, only very limited reports have demonstrated the fabrication of biodegradable AIE-active FONs with red fluorescence emission. In this study, a novel strategy has been developed for the preparation of biodegradable AIE-active polyurethanes (PUs) through a two-step polymerization, in which the diisocyanate-terminated polyethylene glycol (NCO-PEG-NCO) was synthesized and subsequently conjugated with diamine-containing AIE dye (NH 2 -Phe-NH 2 ). The successful synthesis of AIE-active Phe-PEG 2000 PUs is evidenced by a series of characterization techniques. Because of the formation of AIE-active amphiphilic PUs, the final copolymers can self-assemble into spherical nanoparticles, which exhibit strong luminescence and high water dispersion. The biological evaluation results suggest that the AIE-active Phe-PEG 2000 FONs possess low toxicity and desirable cell permeability. Therefore, we anticipate that these AIE-active FONs with biodegradable potential will trigger much research enthusiasm and effort toward the creation of new AIE-active materials with improved properties for various biomedical applications. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) dyes based fluorescent polymeric nanoparticles (FNPs) have been intensively explored for biomedical applications. However, many of these AIE-active FNPs are relied on the self-assembly of amphiphilic copolymers, which are not stable in diluted solution. Therefore, the introduction of cross-linkages into these micelles has demonstrated to be an efficient route to overcome this stability problem and endow ultra-low critical micelle concentrations (CMC) of these AIE-active FNPs. In this work, we reported the fabrication of cross-linked AIE-active FNPs through controllable reversible addition fragmentation chain transfer polymerization by using commercially available octavinyl-T8-silsesquioxane (8-vinyl POSS) as the cross-linkage for the first time. The resultant cross-linked amphiphilic copolymers (named as PEG-POSS-PhE) are prone to self-assemble into stable core–shell nanoparticles with well water dispersity, strong red fluorescence and low CMC (0.0069 mg mL −1 ) in aqueous solution. More importantly, PEG-POSS-PhE FNPs possess some other properties such as high water dispersity, uniform morphology and small size, excellent biocompatibility and cellular internalization, providing great potential of PEG-POSS-PhE FNPs for biological imaging application. [ABSTRACT FROM AUTHOR]

Fluorescence probes play a crucial role in optical imaging for visualization of complex biological processes. As compared with conventional organic fluorogens, the probes with aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) characteristics show significant advantages in high quantum yield at concentrated and aggregated state, large Stokes shift and low cytotoxicity. However, the synthesis of AIE-active fluorescent probes through the ESIPT mechanism has received only very limited attention. On the other hand, the preparation of biodegradable fluorescent probes through the ESIPT mechanism has not been demonstrated thus far. In this work, we reported for the first time that water dispersible and biodegradable fluorescent polymeric nanoparticles with AIE and ESIPT characteristics could be facilely obtained through conjugation of 2,4-Dihydroxybenzophenone based benzophenone azine (BPA) and polyethylene glycol (PEG) using hexamethylene diisocyanate. The final copolymers contained hydrophilic and biocompatible PEG and biodegradable urethane linkage are readily self-assembled into core-shell nanostructures. Moreover, the self-assembled BPA-PEG 2000 fluorescent organic nanoparticles (FONs) displayed obvious AIE feature, high water dispersibility, superb biocompatibility, biodegradability and excellent cell dyeing performance. All of the above properties implied that BPA-PEG 2000 FONs are promising candidates for a variety of biomedical applications. [ABSTRACT FROM AUTHOR]

The development of simple and effective methods for synthesis of fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) plays an important role for the biomedical applications of AIE-active FPNs. In present work, we developed a facile strategy for the fabrication of AIE-active FPNs by a post-polymerization method based on the microwave-assisted Kabachnik–Fields (KF) reaction, which can conjugate with poly(PEGMA-NH 2 ), AIE-active dye (TPE-CHO) and diethyl phosphate (DP) under microwave irradiation within 5 min. The characterization results confirm that PEGMA-TPE FPNs are successfully prepared through the microwave-assisted KF reaction. The resultant AIE-active FPNs show high water dispersity, intensive fluorescence and low cytotoxicity. These features make these AIE-active FPNs great potential for biomedical applications. Moreover, the microwave-assisted KF reaction is simple, fast, atom economy that should be a general strategy for the fabrication of various multifunctional AIE-active FPNs. We believe this work will open up a new avenue for the preparation of AIE-active functional materials with great potential for different applications. [ABSTRACT FROM AUTHOR]

The development of luminescent bioprobes based on organic dyes with aggregation-induced emission (AIE) characteristic has attracted great attention in recent years. In this work, we reported for the first time that AIE-active luminescent polymeric nanoparticles (LPNs) can be facilely prepared via a one-step acetalization reaction, which can be used to conjugate the aldehyde group containing AIE dye (PTH-CHO) and methoxypolyethylene glycols (mPEG-CHO) with a commercially available dendritic polyester (H40) using p-toluenesulfonic acid (TsOH) as the catalyst. As-prepared star -shaped hyperbranched luminescent polymers (named as H40-mPEG-mPTH) were prone to self-assemble into core-shell nanoparticles in aqueous solution because of their amphiphilic structure, in which hydrophobic components (such as PTH-CHO and H40) were encapsulated in the core while the hydrophilic components (mPEG-CHO) were acted as the shell. The final AIE-active H40-mPEG-mPTH LPNs displayed uniform spherical structure, strong fluorescence, excellent photostability and high water dispersity. Furthermore, biological evaluation results demonstrated that H40-mPEG-mPTH LPNs possess low toxicity and excellent biocompatibility, indicating their great potential for biomedical applications. Taken together, we reported a novel strategy for the construction of hyperbranched and biodegradable LPNs with AIE feature through a one-step acetalization reaction, which can be also utilized for construction of many other AIE-active LPNs with a variety structure and properties. [ABSTRACT FROM AUTHOR]

Luminescent polymeric nanoparticles (LPNs) with aggregation-induced emission (AIE) feature have emerged as the most promising candidates for biological imaging owing to their unique AIE feature, great water dispersity, strong fluorescence, low cytotoxicity and biocompatibility. Although numerous successful strategies for construction of AIE-active LPNs have been developed, the preparation of dynamic linkages containing AIE-active LPNs based on multicomponent reactions has been rarely reported. In this work, we report a facile method for the formation of AIE-active LPNs via a one-pot conjugation of PEG-B(OH) 2 , 1-thioglycerol and AIE-active dye PhE-alc in short time under rather mild reaction conditions (e.g. ambient temperature, air atmosphere, absent of metal catalysts and in the present of water). The successful formation of AIE-active mPEG-PhE LPNs was confirmed by different characterization techniques in details. The great optical and biological properties certified their applicable for biological imaging application. More importantly, the novel method for the formation of AIE-active LPNs is rather simple, high efficiency and atom economy, which greatly enriched their practical biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) characteristics have attracted much attention for biomedical applications due to their remarkable AIE feature, high water dispersity and desirable biocompatibility. The development of facile and effective strategies for fabrication of these AIE-active FPNs therefore should be of great importance for their biomedical applications. In this work, we reported that a catalyst-free thiol-yne click reaction can be utilized for fabrication of AIE-active FPNs in short reaction time and even without protection of inert gas. The results indicated that the obtained AIE-active amphiphilic copolymers (PEGMA-PhE) can readily self-assemble into luminescent nanoparticles (PEGMA-PhE FPNs) with high water dispersity, uniform size and morphology, red fluorescence. Cell viability examination and cell uptake behavior of PEGMA-PhE FPNs confirmed that these AIE-active FPNs possess low toxicity towards cells and can be easily internalized by cells through non-specific route. Therefore the remarkable properties of PEGMA-PhE FPNs such as high water dispersity, AIE-active fluorescence and nanoscale size as well as excellent biocompatibility make them promising for biomedical applications. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) dyes have recently been intensively explored for biological imaging applications owing to their outstanding optical feature as compared with conventional organic dyes. The AIE-active luminescent silica nanoparticles (LSNPs) are expected to combine the advantages both of silica nanoparticles and AIE-active dyes. Although the AIE-active LSNPs have been prepared previously, surface modification of these AIE-active LSNPs with functional polymers has not been reported thus far. In this work, we reported a rather facile and general strategy for preparation of polymers functionalized AIE-active LSNPs through the surface-initiated atom transfer radical polymerization (ATRP). The AIE-active LSNPs were fabricated via direct encapsulation of AIE-active dye into silica nanoparticles through a non-covalent modified Stöber method. The ATRP initiator was subsequently immobilized onto these AIE-active LSNPs through amidation reaction between 3-aminopropyl-triethoxy-silane and 2-bromoisobutyryl bromide. Finally, the zwitterionic 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) was selected as model monomer and grafted onto MSNs through ATRP. The characterization results suggested that LSNPs can be successfully modified with poly(MPC) through surface-initiated ATRP. The biological evaluation results demonstrated that the final SNPs-AIE-pMPC composites possess low cytotoxicity, desirable optical properties and great potential for biological imaging. Taken together, we demonstrated that AIE-active LSNPs can be fabricated and surface modified with functional polymers to endow novel functions and better performance for biomedical applications. More importantly, this strategy developed in this work could also be extended for fabrication of many other LSNPs polymer composites owing to the good monomer adoptability of ATRP. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) active fluorescent polymeric nanoparticles (FPNs) have recently emerged as the promising nanoprobes for biological imaging for their intensive fluorescence, good photostability, desirable biocompatibility and well designability of structure and optical properties. Herein, we proposed a novel strategy for fabrication of AIE-active FPNs through the post modification of synthetic copolymers to form Schiff base. The size, morphology, optical properties and biocompatibility as well as cell uptake behavior were evaluated in detailed. To fabricate these AIE-active FPNs, poly(PEG- co -VA) copolymers were first obtained via addition-fragmentation chain transfer polymerization using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3-vinylaniline (VA) as the monomers. Then the AIE-active SA-poly(PEG- co -VA) FPNs were formed through the reaction between salicylaldehyde (SA) and VA. Results demonstrated that SA-poly(PEG- co -VA) FPNs possess bright fluorescence, superior photo-bleaching resistance, excellent biocompatibility and efficient cell uptake behavior. To the best of our knowledge, this is the first report for fabrication AIE-active FPNs through post modification of synthetic copolymers. The facile fabrication procedure and the remarkable features suggested that these AIE-active FPNs promising candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

The poly(amino acid)s based biomaterials have attracted great research attention over the past few decades because of their biocompatibility, biodegradability and well designability. Although much progress has achieved in the synthesis and biomedical applications of poly(amino acid)s, the synthesis of luminescent poly(amino acid)s has been rarely reported. In this work, novel amphiphilic luminescent poly(amino acid)s with aggregation-induced emission (AIE) feature have been synthesized by a new approach of controlling N -carboxy anhydride (NCA) ring-opening polymerization, in which hydrophobic 2-(4-aminophenyl)-3-(10-hexadecyl-4H-phenothiazin-3-yl)acrylonitrile (Phe-NH 2 ) with AIE feature was used as initiator and hydrophilic oligomeric glycol functionalized glutamate (OEG-glu) NCA was acted as monomer. The successful synthesis of final Phe-OEG-Pglu polymers was confirmed by different characterization techniques. Phe-OEG-Pglu polymers possess amphiphilic properties and can self-assemble into luminescent polymeric nanoparticles (LPNs). Based on cellular imaging experiments, we demonstrated that Phe-OEG-Pglu LPNs have great potential for bio-imaging applications due to their attractive properties including strong fluorescence intensity, great water dispersibility, excellent biocompatibility and high cellular uptake efficiency. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) active fluorescence polymeric nanoparticles (FPNs) have recently received increasing interests for biomedical applications such as cell imaging, drug delivery, disease diagnosis and treatment. Fabricated strategies of AIE-active FPNs with high efficiency, simplification and tenderness are still passionately pursued to promote the development of theranostic systems. In this work, we develop a facile method for the preparation of AIE-active FPNs by adopting Ce(IV)/HNO 3 redox polymerization under near room temperature. Thus-prepared FPNs (named as PEG-PLC-1) possess unique AIE feature, great water dispersity, excellent biocompatibility and biodegradability because of the conjugation of ultra-bright AIE dye (PhE-alc) and biodegradable PEG-PCL linear copolymers. The 1 H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), UV–Visible and fluorescence spectrometers were used to confirm the successful fabrication of AIE-active FPNs. Cell viability and cellular uptake behavior of PEG-PLC-1 FPNs were further investigated for their potential biomedical applications. Results demonstrated that PEG-PLC-1 FPNs are high water dispersity, intensive luminescence and low cytotoxicity, making them very attractive for biomedical applications. More importantly, the method for the fabrication of AIE-active biodegradable FPNs can be occurred under rather facile conditions (e.g., low temperature, free of metal catalysts, common chain transfer agent and aqueous solution) and are specially used for fabrication of AIE-active polysaccharides with poor organic solubility. [ABSTRACT FROM AUTHOR]

Aggregation-induced emission (AIE) phenomenon has attracted great attention recently and been extensively explored for biomedical applications. Nevertheless, the direct utilization of AIE-active dyes for biomedical applications has demonstrated to be enormous challenge owing to the hydrophobic nature of these AIE-active dyes. In this work, we reported the fabrication of amphiphilic AIE-active copolymers through the specific host-guest interaction between β cyclodextrin (β-CD) and an adamantine terminating tetraphenylethene derivative (TPE-Ad). In this construction system, β-CD was acted as the bridge to link TPE-Ad with PEG. The TPE-β-CD-PEG copolymers were characterized by various equipments in detail. Cytocompatibility and cell uptake behavior of TPE-β-CD-PEG were also examined to evaluate their biomedical application potential. Results demonstrated that TPE-β-CD-PEG copolymers were prone to self-assemble into luminescent nanoparticles, which exhibited high water dispersity, AIE feature and excellent biocompatibility. These features endowed TPE-β-CD-PEG great potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescent nanodiamond (FND) has received increasing research interests for bioimaging and drug delivery owing its outstanding physicochemical properties and low toxicity. However, synthesis of FND in large scale with desirable optical property is still a big challenge. In this work, we reported for the first time that non-fluorescent ND can be facilely converted into FND through surface modified with aggregation-induced emission fluorophore containing luminescent polymers through the microwave-assisted typical Diels-Alder (D-A) reaction. The final FND (named as ND-poly(Phe-PEGMA-IA)) displayed extensive fluorescence, high water dispersibility and desirable biocompatibility. Cell imaging results demonstrated ND-poly(Phe-PEGMA-IA) exhibited great stain performance. Furthermore, anticancer drug (cisplatin, DDP) can be effectively loaded onto ND-poly(Phe-PEGMA-IA) and controlled release it under acidic environment. All of these favorable properties endow ND-poly(Phe-PEGMA-IA) great potential for biological tracing and controlled drug delivery. Taken together, we have developed a microwave-assisted D-A reaction for preparation of multifunctional FND with great potential for biological imaging and controlled drug delivery applications. [ABSTRACT FROM AUTHOR]

In recent years, aggregation-induced emission (AIE) dyes based fluorescent organic nanoparticles (FONs) have achieved significant progress in various biomedical applications. In this work, we developed a covalent strategy to prepare biocompatible AIE-active dyes based cross-linked copolymers (MPC-POSS-PhE) via controllable reversible addition fragmentation chain transfer (RAFT) polymerization using zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC), polymerizable AIE dye (named as PhE) and 8-vinyl polyoctahedral silsesquioxanes (POSS) as monomers. Due to the existence of hydrophilic MPC and hydrophobic PhE, the resultant copolymers will self-assemble into core-shell nanoparticles in aqueous solution with ultra-low critical micelle concentration (CMC). This could effectively overcome the drawbacks of non-crosslinked micelles and show more attractive properties and better performance for biomedical applications. Furthermore, the characterization results and biological assays demonstrated that the final MPC-POSS-PhE FONs show stable aqueous stability, uniform size and morphology, high water dispersity, desirable optical properties and low cytotoxicity. These remarkable properties make the resultant AIE-active nanoprobes great potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Fluorescent silica nanoparticles (FSNPs) have been extensively investigated for various biomedical applications in recently years. However, the aggregation of organic dyes in silica nanoparticles also leads the significant fluorescence quenching owing to the aggregation caused quenching effects of organic dyes. Herein, we developed a rather facile strategy to fabricate FSNPs with desirable fluorescent properties through non-covalent incorporation of fluorophores with aggregation-induced emission (AIE) feature into silica nanoparticles, which were subsequently modified with functional polymers. The resultant FSNPs polymer nanocomposites (named as FSNPs-poly(IA- co -PEGMA)) exhibited uniform spherical morphology, high water dispersiity, and bright red fluorescence. Cytotoxicity results indicate that FSNPs-poly(IA- co -PEGMA) possess excellent biocompatibility. Cell uptake behavior suggests FSNPs-poly(IA- co -PEGMA) are of great potential for biological imaging applications. Taken together, we have reported a facile method for the fabrication of FSNPs through non-covalent encapsulation using an AIE-active dye. These FSNPs can be further functionalized with functional polymers through ring-opening reaction and the resultant FSNPs-poly(IA- co -PEGMA) showed great potential for biological imaging. More importantly, we believe that many other functional components could also be integrated into these FSNPs through the facile ring-opening reaction. Therefore, this method should be a facile and general tool for fabrication of polymer functionalized AIE-active FSNPs. [ABSTRACT FROM AUTHOR]

Amphiphilic molecules with aggregation-induced emission (AIE) characteristics have attracted intensive interest for biological imaging applications for their self-assembly into nanostructures and obvious enhanced fluorescence intensity in aqueous solution. Although many AIE-active fluorescent organic nanoparticles (FONs) have been fabricated recently, the direct linkage of hydrophilic small molecules and hydrophobic AIE dyes has rarely been reported. In this work, we reported a one-pot strategy for preparation of adenosine triphosphate (ATP) containing molecules that conjugated the amino group of ATP and aldehyde-terminated AIE dye (PhCHO) based on mercaptoacetic acid locking imine (MALI) reaction. These AIE-active ATP-PhCHO showed amphiphilic properties and could self-assemble into micelles, which displayed high water dispersibility, strong yellow fluorescence, good biocompatibility and biological imaging capability. These advantages make ATP-PhCHO FONs promising for biomedical applications. [ABSTRACT FROM AUTHOR]