Molecular insight on the binding of halogenated organic phosphate esters to human serum albumin and its effect on cytotoxicity of halogenated organic phosphate esters.

Halogenated Organic Phosphate Esters (OPEs) are commonly found in plasticizers and flame retardants. However, they are one kind of persistent contaminants that can pose a significant threat to human health and ecosystem as new environmental estrogen. In this study, two representative halogenated OPEs, tris(1,3-dichloro-2-propyl) phosphate (TDCP) and tris(2,3-dibromopropyl) phosphate (TDBP), were selected as experimental subjects to investigate their interaction with human serum albumin (HSA). Despite having similar structures, the two ligands exhibited contrasting effects on enzyme activity of HSA, TDCP inhibiting enzyme activity and TDBP activating it. Furthermore, both TDCP and TDBP could bind to HSA at site I, interacted with Arg222 and other residues, and made the conformation of HSA unfolded. Thermodynamic parameters indicated the main driving forces between TDBP and HSA were hydrogen bonding and van der Waals forces, while TDCP was mainly hydrophobic force. Molecular simulations found that more hydrogen bonds of HSA-TDBP formed during the binding process, and the larger charge area of TDBP than TDCP could partially account for the differences observed in their binding abilities to HSA. Notably, the cytotoxicity of TDBP/TDCP was inversely proportional to their binding ability to HSA, implying a new method for determining the cytotoxicity of halogenated OPEs in vitro.

Epigenomic mechanism regulating the quality and ripeness of apple fruit with differing harvest maturity.

Harvest maturity significantly affects the quality of apple fruit in post-harvest storage process. Although the regulatory mechanisms underlying fruit ripening have been studied, the associated epigenetic modifications remain unclear. Thus, we compared the DNA methylation changes and the transcriptional responses of mature fruit (MF) and immature fruit (NF). There were significant correlations between DNA methylation and gene expression. Moreover, the sugar contents (sucrose, glucose, and fructose) were higher in MF than in NF, whereas the opposite pattern was detected for the starch content. The expression-level differences were due to DNA methylations and ultimately resulted in diverse fruit textures and ripeness. Furthermore, the higher ethylene, auxin, and abscisic acid levels in MF than in NF, which influenced the fruit texture and ripening, were associated with multiple differentially expressed genes in hormone synthesis, signaling, and response pathways (ACS, ACO, ZEP, NCED, and ABA2) that were regulated by DNA methylations. Multiple transcription factor genes involved in regulating fruit ripening and quality via changes in DNA methylation were identified, including MIKCC-type MADS-box genes and fruit ripening-related genes (NAP, SPL, WRKY, and NAC genes). These findings reflect the diversity in the epigenetic regulation of gene expression and may be relevant for elucidating the epigenetic regulatory mechanism underlying the ripening and quality of apple fruit with differing harvest maturity.

One-step synthesis of a dual-functional AIE-active probe for ClO- detection and photodynamic therapy.

An amphiphilic fluorescent probe (BHSMP) with aggregation-induced emission (AIE) features was synthesized via a one-step route. The probe showed high water dispersibility, low toxicity and the ability of selective and sensitive (limit of detection of 0.11 µM) detection of ClO- with fast-response (≤30 s) in aqueous solution and living organisms. Owing to the donor-acceptor (D-A) structure and existence of cationic groups, BHSMP could also generate reactive oxygen species under light-irradiation and potentially be utilized for photodynamic therapy. The strategy described in this work is of great significance for the design and synthesis of multifunctional AIE-active functional materials to facilitate their biomedical applications.

Comparative Proteomic and Metabonomic Profiling of Buds with Different Flowering Capabilities Reveal Novel Regulatory Mechanisms of Flowering in Apple.

Flower bud formation in the apple tree life cycle is associated with multiple biological processes. To explore the physiological and molecular mechanisms underlying the protein and metabolite changes in buds with different flowering capabilities, axillary buds with no flowering (Ab), long-shoot buds with a low flowering rate (Lb), and spur buds with a higher flowering rate than the Lb (Sb) were analyzed using a Tandem Mass Tag™ proteomic technique in combination with nLC-MS/MS analyses. We identified 471 (88 up- and 383 down-regulated), 459 (176 up- and 283 down-regulated), and 548 (387 up- and 161 down-regulated) differentially expressed proteins in Sb vs. Lb, Sb vs. Ab, and Lb vs. Ab, respectively, that were involved in carbohydrate, amino acid and lipid transport, and metabolism. Additionally, 110 (91 increased and 19 decreased), 89 (71 increased and 18 decreased), and 99 (37 increased and 62 decreased) metabolites having significantly different levels were identified in Sb vs. Lb, Sb vs. Ab, and Lb vs. Ab, respectively. The identified metabolites were related to amino acids and their isoforms, sugars and polyols, and organic acids, and occurred at significantly greater levels in the Sbs than the other buds. Thus, flower bud formation is a complex process that involves various biochemical materials and signals, such as carbohydrates, amino acids and their isoforms, and organic acids.

A dual-function probe with aggregation-induced emission feature for Cu2+ detection and chemodynamic therapy.

Herein, a fluorescent probe (named TPACP) with aggregation-induced emission (AIE) feature was developed and utilized for the selective detection of Cu2+ with high sensitivity and fast-response. The resultant TPACP@Cu2+ complexes from coordination of TPACP with Cu2+ can also be potentially applied for chemodynamic and photodynamic therapy.

Transcriptome analysis reveals dual action of salicylic acid application in the induction of flowering in Malus domestica.

In the apple tree, insufficient flower bud production is an intractable challenge, and very little information is available in this field due to the fact that research done in this sector is very rare owing to its extended life cycles and low rate of genetic transformation. Here we display novel changes and events in spur buds of Malus × domestica trees after they were exposed to salicylic acid (SA) treatment during the flower induction period. We found a significant increase in morphological indexes, followed by a wider and well-defined shoot apical meristem in SA-treated spur buds. Additionally, we observed increased oxidative stress markers and enzymatic antioxidants in control-treated buds during the flower induction period, while non-enzymatic antioxidants were recorded higher in SA-treated buds. Maximum flowering was observed in SA-treated trees in the next year. Furthermore, ultra-high-performance liquid chromatography (u-HPLC) analysis displays that SA treatment enhances SA and indole acetic acid (IAA), while having an antagonistic effect on gibberellin (GA). At different time points, transcriptome analysis was conducted to analyze the transcriptional response of CK and SA treated buds. Pathway enrichment was detected in differentially expressed genes (DEGs). Agamous (AGL) and SQUAMOSA-promoter binding protein-like (SPL) family related flowering genes display a positive signal for the increased flowering in SA-treated trees, which confirms our findings. As far as we know, there is no report available on the response of spur buds to SA treatment during the flower induction period. This data provides a new theoretical reference for the management of apple tree flowering and also provides an essential basis for future analysis of the regulation and control of flowering in M. domestica.

Fabrication of chitosan based luminescent nanoprobe with aggregation-induced emission feature through ultrasonic treatment.

Chitosan is an abundant natural polysaccharide that contains a lot of amino and hydroxyl groups. It possesses great potential for biomedical applications owing to its low toxicity, biodegradability and low cost. Herein, a novel chitosan-based fluorescent copolymer (WS-CS-TPA) was designed and synthesized via nucleophilic substitution of hexachlorocyclotriphosphazene (HCCP), water-soluble chitosan (WS-CS) and an aggregation-induced emission (AIE) fluorogen (AIEgen) triphenylamine derivative (TPA-NH2). Under ultrasonic treatment, 1.16 g TPA-NH2 and 1.1 g WS-CS can be conjugated by 0.7 g HCCP at room temperature. The obtained copolymer shows amphiphilic property and could assemble into nanoparticles with size about 100 nm. After self-assembly, TPA-NH2 was aggregated in the core, thus exhibiting superb AIE feature with intense green fluorescence emission in aqueous media. On the other hand, hydrophilic WS-CS was coated on the surface of nanoparticles and endowed their high water dispersibility. Results from preliminary biological assays suggested that WS-CS-TPA can be internalized by cells and exhibits low cytotoxicity, suggesting their great potential for biological imaging and intracellular drug delivery.

Application of sodium bicarbonate in extraction and determination of synthetic colorant in processed grain products.

As the only standard of its kind, GB5009.35-2016 provides the determination of water-soluble synthetic colorants in processed grain products with high starch content for the purpose of food safety risk monitoring. However, it's only applicable to candy products and liquid foods as beverages, but not solid grain products. Extraction is a critical and essential step in the overall analytical process for determination. This paper provides an improved method for extraction of synthetic colorants in food products presenting high starch content. The samples were successively extracted with methanol-water (4:6, v/v) containing 2.7% sodium bicarbonate, and the target analytes were purified by solid phase extraction column. The obtained eluent was concentrated in constant volume, separated by ODS-SP C18 column and determined by diode array detector. The limits of detection were in the range of 2.21 ~ 8.62 ng/mL for 6 synthetic colors. The average recoveries at the spiked levels of 10, 30, 50 µg/kg varied in the range of 79.3 ~ 101.4% with RSD (n = 6) around 0.2 ~ 6.7%. The developed sodium bicarbonate based extraction method was successfully applied to speciation analysis of water soluble azo synthetic colorant in starchy food, such as millet, grits, brown rice, rice flour, cornmeal and cornflakes. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05199-x.

Surface functionalization of MXene with chitosan through in-situ formation of polyimidazoles and its adsorption properties.

In this work, a novel imidazoles-MXene hybrid composite, namely polyimidazoles chain overlaying on the surface of MXene (Ti3C2@IMIZ), was prepared by a simple method. Through this strategy, imidazoles can be in situ growth on the surface of MXenes via a facile multicomponent reaction using chitosan as a renewable reactant. Based on the characterization results, we demonstrated that a thin layer imidazoles with an ordered chain structure was embedded on the surface of Ti3C2, which resulted in the formation of a novel imidazoles-MXene hybrid composite. The adsorption performance of Ti3C2@IMIZ for removal environmental pollutants was evaluated using heavy metal ions of Cr(Ⅵ) as adsorbate. Detailed adsorption characteristics of Ti3C2@IMIZ including operational factors, adsorption kinetics and isotherms models were investigated. XPS analysis showed that Cr(VI) was converted to Cr(III) with low toxicity during the adsorption process. The adsorption of Cr(VI) and reduction of Cr(VI) to Cr(III) contribute to elimination of Cr(VI) species. The adsorption behavior and process analysis show that the adsorption mechanism is mainly physical adsorption through electrostatic interaction. The excellent reproducibility suggests that Ti3C2@IMIZ may be a potential candidate for remove of Cr(Ⅵ) in actual sewage treatment.

Surface grafting of fluorescent polymers on halloysite nanotubes through metal-free light-induced controlled polymerization: Preparation, characterization and biological imaging.

Halloysite nanotubes (HNTs) are a kind of aluminosilicate clay with a unique hollow tubular structure that has been intensively explored for various applications especially in biomedical fields owing to their excellent biocompatibility, biodegrading potential and low cost. Surface modification of HNTs with functional polymers will greatly improve their properties and endow new functions for biomedical applications. In this work, a light-induced reversible addition-fragmentation chain transfer (RAFT) polymerization was introduced to successfully prepare HNTs based fluorescent HNTs/poly(PEGMA-Fl) composites in the presence of oxygen using diacrylate-fluorescein and poly (ethylene glycol) methyl ether methacrylate (PEGMA) as the monomers. Without other catalysts, heating, and deoxygenation procedure, the polymerization process can take place under mild conditions. Besides, owing to the introduction of fluorescein and PEGMA on the surface of HNTs, the resultant HNTs/poly(PEGMA-Fl) composites display high water dispersibility and stable fluorescence. The results from cell viability examination and confocal laser scanning microscopy also demonstrated that HNTs/poly(PEGMA-Fl) composites could be internalized by L929 cells with bright fluorescence and low cytotoxicity. Taken together, we developed a novel photo-initiated RAFT polymerization method for the fabrication of HNTs based fluorescent polymeric composites with great potential for biomedical applications. More importantly, many other multifunctional HNTs based polymer composites could also be fabricated through a similar strategy owing to good designability of RAFT polymerization.

Preparation and biological imaging of fluorescent hydroxyapatite nanoparticles with poly(2-ethyl-2-oxazoline) through surface-initiated cationic ring-opening polymerization.

Fluorescent hydroxyapatite (HAp) nanoparticles have received significant attention in biomedical fields due to their outstanding advantages, such as low immunogenicity, excellent biocompatibility and biodegradability. However, fluorescent HAp nanoparticles with well controlled size and morphology are coated with hydrophobic molecules and their biomedical applications are largely restricted by their poor dispersibility in physiological solutions. Therefore, surface modification of these hydrophobic fluorescent HAp nanoparticles to render them water dispersibility is of utmost importance for biomedical applications. In this work, we reported for the first time for preparation of water-dispersible hydrophilic fluorescent Eu3+-doped HAp nanoparticles (named as HAp-PEOTx) through the cationic ring-opening polymerization using hydrophilic and biocompatible 2-ethyl-2-oxazoline (EOTx) as the monomer. The characterization techniques, such as nuclear magnetic resonance (NMR) spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have been used to characterize these samples. Results confirmed that we could successfully obtain the hydrophilic fluorescent HAp-PEOTx composites through the strategy described above. These fluorescent HAp-PEOTx composites display great water dispersibility, unique fluorescent properties and excellent biocompatibility, making them promising for in vitro bioimaging applications.

Facile fabrication of glycosylated and PEGylated carbon nanotubes through the combination of mussel inspired chemistry and surface-initiated ATRP.

Surface modification of carbon nanotubes (CNTs) through controlled living polymerization has demonstrated to be a useful route for preparation of CNTs based polymer composites. However, surface oxidation of CNTs is often required to generate functional groups, which can be further utilized for immobilization of polymerization initiator and grafting polymers. The surface oxidation procedure is rather complex, high energy cost, low efficient and will destroy the structure of CNTs. Therefore, the development of simple and efficient strategies for preparation of CNTs based composites should be of great research interest and raised much attention recently. In this work, a novel mussel inspired strategy that combination of ATRP and ring-opening reaction has been developed for simultaneous preparation of glycosylated and PEGylated CNTs for the first time. CNTs were first coated with polydopamine (PDA) through self-polymerization of dopamine under alkaline aqueous solution. Then polymerization initiator was immobilized on CNT-PDA through simple esterification and amidation reaction to obtain CNT-PDA-Br. The PEGylated CNTs were synthesized through ATRP using CNT-PDA-Br as initiator and polyethylene glycol monoester acrylate and itaconic anhydride (IA) as the monomers. Finally, glucosamine was conjugated with IA via ring-opening reaction. The successful preparation of glycosylated and PEGylated CNTs (CNT-PDA-Poly(PEGMA-co-IA)-Glu) was confirmed by a number of characterization techniques in details. The obtained CNTs based composites showed improved aqueous dispersibility and desirable cytocompatibility, implying their biomedical application potential. As compared with the conventional covalent strategies, the mussel inspired method described in this work will not destroy the structure for introduction functional groups on the surface of CNTs, that can occur under rather mild experimental conditions, including room temperature, short reaction time and aqueous solution. On the other hand, the mussel inspired chemistry can also be used for surface modification of almost any materials regardless of their size, morphology and compositions. Therefore, we believe that the mussel inspired strategy should be a general method for fabrication of various polymer composites for different applications.

Facile preparation of fluorescent nanodiamond based polymer nanoparticles via ring-opening polymerization and their biological imaging.

Fluorescent nanodiamond (ND) has been regarded as one of the most promising fluorescent nanoprobes owing to their chemical inert, biocompatibility, optical properties, and rich surface chemistry. The fluorescent ND has been mainly fabricated through high-energy ion beam irradiation of type Ib diamonds and subsequent thermal annealing. The generation of nitrogen-vacancy centers is the reason for the fluorescence. However, the physical method is relatively complicated and it need to expensive equipment as well as high cost. On the other hand, the resultant fluorescent ND particles are lack of functional groups and difficult to be dispersed in aqueous solution. Therefore, the development of facile methods to direct preparation of fluorescent ND and surface modification with functional polymers is of great research interest for expanding the biomedical applications of fluorescent ND. In this report, a facile strategy was reported for the first time to prepare hydrophilic polymers functionalized fluorescent ND (named as ND-PhE-PETOx) composites through the ring-opening polymerization and simultaneous simple nucleophilic substitution reaction using the non-fluorescent detonation ND as the raw material. The obtained fluorescent ND composites were characterized by various characterization techniques in details. The as-obtained ND-PhE-PETOx composites exhibit high water dispersibility, low toxicity and strong fluorescence intensity. Cell uptake results indicating that the fluorescent ND based composites can be effectively internalized by cells. Taken together, we have developed a novel and simple method for the preparation of fluorescent ND based composites, which show excellent physicochemical properties and great potential for biomedical applications.

Surface modification of fluorescent Tb3+-doped layered double hydroxides with hyperbranched polymers through host-guest interaction.

The preparation of fluorescent inorganic-organic polymer composites for biomedical applications has become one of the most interest research focuses recently. In this work, we reported a novel method for the preparation of Tb3+-doped luminescent layered double hydroxides (LDHs) based composites by taken advantage of a one-pot supramolecular chemistry. The adamantane can be immobilized on the surface of Tb3+-doped LDHs to obtain LDH-Ad, which could be further utilized for modified by the ß-cyclodextrin (ß-CD) containing hyperbranched polyglycerols (ß-CD-HPG) through the host-guest interaction. Based on the characterization results, we demonstrated that the hyperbranched polyglycerol could be facilely introduced on these fluorescent Tb3+-doped LDHs through the method described in this work. The obtained Tb3+-doped LDHs based polymer composites (LDHs-ß-CD-HPG) display improved water dispersibility and still maintain their fluorescence. The results based on various biological assays suggest that LDHs-ß-CD-HPG polymer composites are of low cytotoxicity and their cell uptake behavior can be effectively traced using confocal laser imaging. All of the above results demonstrated that the fluorescent Tb3+-doped LDHs based polymer composites could be effectively surface modified with hydrophilic hyperbranched polymers through a one-pot facile host-guest interaction and the resultant fluorescent composites are of excellent physicochemical properties and display great potential for biomedical applications. This novel surface modification method should also be important for fabrication of other multifunctional composites and therefore great advanced the development of biomedical applications of fluorescent LDHs based polymer composites and related materials.

A facile surface modification strategy for fabrication of fluorescent silica nanoparticles with the aggregation-induced emission dye through surface-initiated cationic ring opening polymerization.

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.

One-pot ultrafast preparation of silica quantum dots and their utilization for fabrication of luminescent mesoporous silica nanoparticles.

Silica quantum dots (SiQDs) and their luminescent composites have displayed great potential for biomedical applications owing to their chemical inert and low cost. In this work, we report a facile, cost-effective and ultrafast strategy to prepare a stable luminescent SiQDs using N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) and salicylaldehyde as precursors for the first time. These luminescent SiQDs were further utilized for fabrication of luminescent mesoporous silica nanoparticles (MSNs) through direct encapsulation of SiQDs by MSNs. The novel synthetic and modified SiQDs uses commercial raw materials and the entire reaction can be completed within 30 s. The successful preparation of SiQDs and SiQDs@MSNs were characterized by various characterization equipments. The cell viability as well as cell uptake behavior of SiQDs@MSNs were also examined to evaluate their potential for biomedical applications. We demonstrated that these SiQDs@MSNs are low toxicity and of great potential for biological imaging. Based on the above results, we believe that these SiQDs@MSNs should be novel and promising candidates for biomedical applications owing to their intense fluorescence, biocompatibility and high specific surface areas.

A novel strategy for fabrication of fluorescent hydroxyapatite based polymer composites through the combination of surface ligand exchange and self-catalyzed ATRP.

A novel and facile strategy that combination of surface ligand exchange and photo-initiated atom transfer radical polymerization (ATRP) has been developed for the preparation of fluorescent hydroxyapatite (HAp) based polymer composites, which were utilized for biological imaging applications. In particular, the photo-initiated ATRP not only inherited advantages of traditional ATRP but also overcome its deficiencies such as high energy consumption, transition metal contamination and long reaction time. In this method, a hydrophilic and biocompatible PEGMA was introduced to enhance the hydrophilic and biocompatibility of HAp nanocomposites. Simultaneously, the HAp-poly(PEGMA-co-AcFl) composites are endowed with bright green fluorescence by grafting with AcFl on the surface via copolymerization. The physicochemical properties of HAp-poly(PEGMA-co-AcFl) composites were characterized by a series of methods in detail. Results confirmed that HAp-poly(PEGMA-co-AcFl) composites possess controlled size and morphology, high water dispersibility and strong fluorescence. The cell viability and cell uptake behavior demonstrated that HAp-poly(PEGMA-co-AcFl) composites present low toxicity and can be potentially used for biological imaging. Taken together, we have developed a facile and efficient method for the fabrication of fluorescent HAp composites with desirable physicochemical and biological properties.

Surface PEGylation and biological imaging of fluorescent Tb3+-doped layered double hydroxides through the photoinduced RAFT polymerization.

Tb3+-doped layered double hydroxides (LDHs) exhibit excellent optical characteristics, uniform size and uniform morphologies when synthesized through a hydrothermal method. However, due to their lack of functional groups and poor dispersibility, applications of these fluorescent Tb3+-doped LDHs have been largely impeded especially in the biomedical fields. In this work, a novel strategy was developed for the surface modification of these fluorescent Tb3+-doped LDHs using photoinduced surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization with hydrophilic poly(ethylene glycol) methacrylate (PEGMA) as the monomer. The final products were obtained via the metal free surface-initiated RAFT polymerization with light irradiation. Successful preparation of these fluorescent LDHs polymer composites (LDH-PEG) was confirmed by a number of analytical technologies, such as transmission electron microscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. In addition, laser scanning confocal microscope was employed to examine the cell uptake behavior of the LDH-PEG composites and evaluate their potential for biomedical applications. We demonstrated that the hydrophilic monomer PEGMA could be facilely grafted on the surface of Tb3+-doped LDHs through metal free photoinduced surface-initiated RAFT polymerization. The resultant LDH-PEG composites displayed high water dispersibility, strong fluorescence, low cytotoxicity and a desirable cell uptake performance. These features of the LDH-PEG composites indicated their great potential for biomedical applications. More importantly, photoinduced RAFT polymerization has the advantages of a conventional controlled living radical polymerization, which could overcome drawbacks such as toxicity, the fluorescence quenching effects of metal catalysts and the complex synthesis of chain transfer agents. Therefore, this method could be an alternative tool for the surface modification of materials and fabrication of multifunctional fluorescent nanomaterials based polymer composites.

Fabrication and characterization of hyperbranched polyglycerol modified carbon nanotubes through the host-guest interactions.

Carbon nanotubes (CNTs) are novel carbon composites that have received extensive research attention for biomedical applications thanks to their excellent cell membrane penetration capability and large specific surface areas. Nevertheless, the poor dispersibility in aqueous solution still perplexes the biomedical applications of CNTs. Although, there are many researched about that modify hydrophilic polymers to the surface of CNTs, facile and efficient strategies are still highly desirable to be developed. In this produce, an efficient and facile strategy for surface modification of CNTs with excellent water dispersibility was developed via supramolecular chemistry. On the one hand, we synthesize the ß-CD-HPG via anionic polymerization. On the other hand, adamantane chloride was first reacted with the hydroxyl group of radiant CNTs through esterification to obtain CNT-Ad. Finally, it only need mild reaction conditions and fast reaction time (30 min) that ß-CD-HPG form an exact 1:1 inclusion complex with CNT-Ad via host-guest interaction. The successful preparation of CNT-ß-CD-HPG composites could be confirmed via a series of characterization techniques. Then, we further verify that CNT-ß-CD-HPG composites possess the remarkable water dispersibility and enormous potential for controlled drug delivery systems. Therefore the facile strategy for the preparation of CNT-ß-CD-HPG composites with excellent water dispersibility via supramolecular chemistry would possess rosy prospects in biomedical applications.

Preparation of water dispersible and biocompatible nanodiamond-poly(amino acid) composites through the ring-opening polymerization.

Nanodiamond (ND) is one of the most fascinating carbon materials that have been extensively investigated for biomedical applications owing to its small size, high specific surface areas, chemical inert and desirable biocompatibility. It has been reported that surface modification of ND with polymers could not only improve the dispersibility of final ND based composites but also endow them novel functions to fulfill the requirement for biomedical applications. Although some strategies have been developed previously, surface modification of ND with poly(amino acid)s has not been reported previously. In this work, poly(amino acid)s functionalized ND composites were fabricated through a ring-opening polymerization of α-amino acid N-carboxyanhydrides (NCAs), which was synthesized by conjugation of hydrophilic ethylene glycol with glutamic acid. The successful preparation of ND-GluEG composites was confirmed by a series of characterization techniques. The results suggest that the water dispersibility of final ND-GluEG composites is obviously improved. Moreover, ND-GluEG composites show low toxicity and are of great potential for biomedical applications.