Luminescent Polymeric Nanoparticles Research Articles

Facile fabrication of luminescent polymeric nanoparticles containing dynamic linkages via a one-pot multicomponent reaction: Synthesis, aggregation-induced emission and biological imaging

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.

The one-step acetalization reaction for construction of hyperbranched and biodegradable luminescent polymeric nanoparticles with aggregation-induced emission feature

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.

Synthesis and cell imaging applications of amphiphilic AIE-active poly(amino acid)s

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-NH2) 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.

Fabrication and biological applications of luminescent polyamidoamine dendrimers with aggregation-induced emission feature

Abstract 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.

Fabrication of aggregation induced emission active luminescent chitosan nanoparticles via a “one-pot” multicomponent reaction

Chitosan based nanomaterials have been extensively examined for biomedical applications for their biodegradability, low toxicity, biological activity and low cost. In this work, a novel strategy for fabrication of luminescent polymeric nanoparticles (LPNs) based on aggregation induced emission (AIE) dye and water soluble chitosan (WS-Chitosan) were firstly developed via a highly efficient mercaptoacetic acid (MA) locking imine reaction. In this multicomponent reaction (MCR), MA serves as “lock” to connect 9,10-Bis(aldehydephenl)anthracene dye (An-CHO) and amino-containing WS-Chitosan under mild reaction conditions. The obtained WS-Chitosan@An-CHO LPNs show strong yellow emission and great water dispersibility. Biological evaluation results demonstrated that synthetic luminescent polymeric nanoparticles possess desirable cytocompatibility and distinct imaging properties. Therefore, we have developed a facile and useful method to fabricate AIE active nanoprobes with desirable properties for various biomedical applications. This strategy should be a general and easy handling tool to fabricate many other AIE dye based materials.

One-step preparation of AIE-active dextran via formation of phenyl borate and their bioimaging application

The fabrication of luminescent polymeric nanoparticles with aggregation induced emission (AIE) properties has been extensively investigated in recent years for their distinct optical properties, biocompatibility and designability. Although a number of AIE-active nanoparticles have been fabricated previously, the AIE-active nanoprobes based on carbohydrate polymers have received only limited attention. In this work, we reported for the first time that AIE-active organic nanoparticles could be prepared via a facile one-step strategy. To fabricate these AIE-active nanoparticles, the AIE dye 9,10-bis (divinylphenylboronic acid) anthracene (An-B(OH)2) terminated with phenylboronic acid was synthesized using anthracene as core chemical structure. After mixing with the An-B(OH)2 and dextran, the resultant products (An-Dex) can be obtained through formation of phenyl borate in aqueous solution, air atmosphere and under room temperature. The intermediates and An-Dex were characterized by a series of characterization techniques including 1H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy. To further explore the biomedical applications of these glycosylated AIE-active nanoparticles, cell viability as well as cell imaging performance of An-Dex nanoparticles was also examined. We demonstrated that An-Dex nanoparticles showed strong fluorescent intensity, great water dispersibility and excellent biocompatibility. More importantly, it is well known that phenyl borate is a dynamic bond, which can potentially response to the pH and glucose. Therefore, the resultant AIE-active probes should be promising candidates for different biomedical applications such as biological imaging and controlled drug delivery.

One-step preparation of branched PEG functionalized AIE-active luminescent polymeric nanoprobes

The synthesis of amphiphilic aggregation-induced emission (AIE) dyes based organic nanoparticles has recently attracted increasing attention in the biomedical fields. These AIE dyes based nanoparticles could effectively overcome the aggregation caused quenching effect of conventional organic dyes, making them promising candidates for fabrication of ultrabright organic luminescent nanomaterials. In this work, AIE-active luminescent polymeric nanoparticles (4-NH2-PEG-TPE-E LPNs) were facilely fabricated through Michael addition reaction between tetraphenylethene acrylate (TPE-E) and 4-arm-poly(ethylene glycol)-amine (4-NH2-PEG) in rather mild ambient. The 4-NH2-PEG can not only endow these AIE-active LPNs good water dispersibility, but also provide functional groups for further conjugation reaction. The size, morphology and luminescent properties of 4-NH2-PEG-TPE-E LPNs were characterized by a series of techniques in detail. Results suggested that these AIE-active LPNs showed spherical morphology with diameter about 100–200 nm. The obtained 4-NH2-PEG-TPE-E LPNs display high water dispersibility and strong fluorescence intensity because of their self assembly and AIE properties of TPE-E. Biological evaluation results demonstrated that 4-NH2-PEG-TPE-E LPNs showed negative toxicity toward cancer cells and good fluorescent imaging performance. All of these features make 4-NH2-PEG-TPE-E LPNs promising candidates for biological imaging and therapeutic applications.

Facile preparation, through Schiff base formation, of luminescent amphiphilic carbohydrate polymers with aggregation-induced emission characteristics for biological imaging

Luminescent polymeric nanoparticles with aggregation-induced emission characteristics were fabricated via formation of a dynamic Schiff base between amino group-containing AIE dye and oxidation starch in the presence of water.

Water dispersible, non-cytotoxic, cross-linked luminescent AIE dots: Facile preparation and bioimaging applications

Fluorescent organic nanoparticles have attracted great current research interest due to their superior properties as compared with small organic dyes and fluorescent inorganic nanoparticles. However, fluorescent organic nanoparticles based on conventional organic dyes often result in significant fluorescence decrease due to the notorious aggregation-caused quenching effect. On the other hand, these fluorescent organic nanoparticles obtained from self-assembly are normally not stable in diluted solution. Therefore, the development of novel fluorescent organic nanoparticles which could overcome these limitations is highly desirable for their practical biomedical applications. In this work, water dispersible, non-cytotoxic and cross-linked luminescent polymeric nanoparticles based on aggregation induced emission dyes were prepared via one pot emulsion polymerization. These cross-linked luminescent polymeric nanoparticles emitted strong red fluorescence and were highly stable in diluted aqueous solution, making them highly potential for various biomedical applications.

Preparation and bioimaging applications of AIE dye cross-linked luminescent polymeric nanoparticles.

With the ever increasing interest in biomedical applications of luminescent probes, the development of novel luminescent nanoparticles which showed high water dispersibility, strong luminescence and excellent biocompatibility has been extensively pursued. In this work, cross-linked luminescent polymeric nanoparticles based on aggregation induced emission (AIE) dyes were fabricated through combination of free radical polymerization and ring-opening reaction using AIE dye as the fluorogen and linker simultaneously. Our results demonstrated that these AIE dye based cross-inked polymeric nanoparticles showed high water dispersibility, remarkable luminescent properties and excellent biocompatibility, is highly potential for biomedical applications.

Ultrabright and biocompatible AIE dye based zwitterionic polymeric nanoparticles for biological imaging

Ultrabright and biocompatible luminescent polymeric nanoparticles were prepared via RAFT polymerization of an AIE dye and a zwitterionic monomer.

Fabrication of luminescent polymeric nanoparticles doped with a lanthanide complex by self-organization process

Recently, a simple method for preparation of polymeric particles with narrow size distribution, “self-organized particle precipitation method”, has been developed. This method is composed of two steps: firstly a solution of a matrix polymer in a volatile solvent is gradually diluted with a freely miscible poor solvent; then the volatile solvent is gradually evaporated from the mixture. In this work, we report preparation of luminescent polystyrene nanoparticles with narrow size distribution from THF solution of polystyrene and trivalent europium, terbium, and samarium complexes as lumophores. Compared with the polystyrene nanoparticles doped with a lanthanide complex possessing no phenyl group, the polystyrene nanoparticles doped with a complex possessing phenyl groups were highly and uniformly luminescent under ultraviolet light irradiation.