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Three-dimensional (3D)-printed scaffolds of biodegradable polymers have been increasingly applied in bone repair and regeneration, which helps avoid the second surgery. PTMC/PCL/TCP composites were made using poly(trimethylene carbonate), poly(ε-caprolactone), and β-tricalcium phosphate. PTMC/PCL/TCP scaffolds were manufactured using a biological 3D printing technique. Furthermore, the properties of PTMC/PCL/TCP scaffolds, such as biodegradation, mechanic properties, drug release, cell cytotoxicity, cell proliferation, and bone repairing capacity, were evaluated. We showed that PTMC/PCL/TCP scaffolds had low cytotoxicity and good biocompatibility, and they also enhanced the proliferation of osteoblast MC3T3-E1 and rBMSC cell lines, which demonstrated improved adhesion, penetration, and proliferation. Moreover, PTMC/PCL/TCP scaffolds can enhance bone induction and regeneration, indicating that they can be used to repair bone defects in vivo.

A luminescence sensor based on an europium(III)-based lanthanide-organic framework, [Eu(BCB)(DMF)]·(DMF)1.5(H2O)2 (1), was synthesized via a solvothermal method using 4,4',4''-benzenetricarbonyltribenzoic acid (H3BCB) as a bridging ligand. Single-crystal X-ray diffraction indicates that Eu centers are eight-coordinated with a trigonal dodecahedron and a square antiprismatic configuration, and adjacent Eu atoms are bridged by BCB organic linkers to form a 3D rod-packing structure. Photoluminescence studies show that compound 1 emits bright red luminescence and behaves as a multi-responsive luminescent sensor toward 4-nitrophenol (4-NP) and I- and Fe3+ ions in water with high sensitivity, selectivity and low detection limits. Furthermore, the possible luminescence sensing mechanisms were also investigated by PXRD analysis, UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The recognition mechanism for 4-NP and I- ions can be attributed to the competition absorption and that for Fe3+ ions is considered to be a multi-quenching mechanism dominated by competition absorption. This study demonstrates that the lanthanide-based MOF might be a promising candidate for the detection of 4-NP and I- and Fe3+ ions in aqueous medium.

Dual-modal magnetic resonance/fluorescent imaging (MRI/FI) attracts moreandmoreattentions in diagnosis of tumors. A corresponding dual-modal imaging agent with sufficient tumor sensitivity and specificity should be matched to improve imaging quality. Tripeptide (RGD) and pentapeptide (YIGSR) were selected as the tumor-targeting groups and attached to gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and rhodamine B (RhB), and then make two novel polypeptide-based derivatives (RGD-Gd-DTPA-RhB and YIGSR-Gd-DTPA-RhB), respectively. These derivatives were further characterized and their properties, such as cell uptake, cell cytotoxicity, MRI and FI assay, were measured. YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB had high relaxivity, good tumor-targeting property, low cell cytotoxicity and good red FI in B16F10 melanoma cells. Moreover, YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB possessed high uptake to B16F10 melanoma, and then achieve highly enhanced FI and MRI of tumors in mice for a prolonged time. Therefore, YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB can be applied as the potential agents for tumor targeted MRI/FI in vivo.

The multi-modal imaging contrast agent has been attracted an increased interest to the tumor detecting and diagnosis in these recent years since the multi-modal imaging technology combines the adva...

Targeted tumor imaging in vivo has been one of the main challenges in the early stage of cancer diagnosis and therapy. However, few contrast probes are available to specifically respond to tumor environments. The aim was to investigate porphyrin-1,8-naphthalimide derivative (APTSPP-2NI) as a potential tumor-targeting fluorescent probe in vitro and in vivo. A tumor-targeting APTSPP-2NI was synthesized by the incorporation of water-soluble 5-(4’-aminophenyl)-10,15,20-tris(4’-sulfonato-phenyl) porphyrin (APTSPP) as a tumor-targeting group into N-butyl-4-ethyldiamino-1,8-naphthalene imide (NI) fluorescence molecule herein. The derivative was further characterized and its properties in vitro and in vivo including the cell cytotoxicity, cell uptake of tumor cells and fluorescent imaging were also evaluated. Experiment results indicated that APTSPP-2NI possessed the low cell cytotoxicity and good tumor-targeting property to the B16F10 melanoma cells. Moreover, APTSPP-2NI can be taken up highly by B16F10 melanoma tumors and then achieve the good green and red fluorescent imaging in B16F10 melanoma tumors. Therefore APTSPP-2NI can be considered as a potential tumor-targeting dual-mode enhanced probe in fluorescent imaging in vitro and in vivo.

Industrial waste lignin was commonly burnt or discharged into river in the past. However, in this study, lignin has been converted into high value-added nano-biochar as a renewable reinforcing filler of styrene-butadiene rubber (SBR) by a simple high-temperature carbonization treatment. Herein, the physicochemical change in lignin before and after carbonization was investigated. It was found that lignin-derived biochar (LB) consisted of vesicle-like primary nanoparticles which were closely packed to form “high-structure” irregular fragments with a high specific surface area (83.41 m2/g). When incorporating LB into SBR, the tensile properties of LB/SBR composites were significantly improved. At the filler loading of 40 phr, the tensile strength and elongation at break of the rubber composite were improved up to 7.1-folds and 2.4-folds of pristine SBR, respectively. Compared to commercial carbon black (CB) N330, the LB showed a similar reinforcing effect on SBR. However, the analysis on the morphology, stress-strain behavior and dynamic mechanical behavior suggested distinct reinforcing mechanisms for LB- and CB-filled rubber composites, due to the difference in the surface properties and structural characteristic of fillers. This work showed the application potential of LB as a renewable substitute of CB in rubber industry and brought environmental and economic benefits for the disposal of lignin.

Photothermal therapy directly acting on the nucleus is a potential anti-tumor treatment with higher killing efficiency. However, in practical applications, it is often difficult to achieve precise nuclear photothermal therapy because agents are difficult to accurately anchor to the nucleus. Therefore, it is urgent to develop a nanoheater that can accurately locate the nucleus. Here, we designed an amphiphilic arginine-rich dendritic peptide (RDP) with the sequence CRRK(RRCG(Fmoc))2, and prepared a nucleus-targeting nanoplatform RDP/I by encapsulating the photothermal agent IR780 in RDP for precise photothermal therapy of the tumor nucleus. The hydrophobic group Fmoc of the dendritic peptide provides strong hydrophobic force to firmly encapsulate IR780, which improves the solubility and stability of IR780. Moreover, the arginine-rich structure facilitates cellular uptake of RDP/I and endows it with the ability to quickly anchor to the nucleus. The nucleus-targeting nanoplatform RDP/I showed efficient nuclear enrichment ability and a significant tumor inhibition effect.

Biodegradable scaffolds based on biomedical polymeric materials have attracted wide interest in bone transplantation for clinical treatment for bone defects without a second operation. The composite materials of poly(trimethylene carbonate), poly(L-lactic acid), and hydroxyapatite (PTMC/PLA/HA and PTMC/HA) were prepared by the modification and blending of PTMC with PLA and HA, respectively. The PTMC/PLA/HA and PTMC/HA scaffolds were further prepared by additive manufacturing using the biological 3D printing method using the PTMC/PLA/HA and PTMC/HA composite materials, respectively. These scaffolds were also characterized by Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), automatic contact-angle, scanning electronic micrographs (SEM), diffraction of X-rays (XRD), differential scanning calorimetry (DSC), and thermogravimetry (TG). Subsequently, their properties, such as mechanical, biodegradation, cell cytotoxicity, cell compatibility in vitro, and proliferation/differentiation assay in vivo, were also investigated. Experiment results indicated that PTMC/PLA/HA and PTMC/HA scaffolds possessed low toxicity, good biodegradability, and good biocompatibility and then enhanced the cell multiplication ability of osteoblast cells (MC3T3-E1). Moreover, PTMC/PLA/HA and PTMC/HA scaffolds enhanced the adhesion and proliferation of MC3T3-E1 cells and enabled the bone cell proliferation and induction of bone tissue formation. Therefore, these composite materials can be used as potential biomaterials for bone repatriation and tissue engineering.

A luminescence sensor based on an europium(III)-based lanthanide-organic framework, [Eu(BCB)(DMF)]·(DMF)

siRNA interference therapy can silence tumor cell target genes and specifically regulate tumor cell behavior and function, which is an effective antitumor therapy. However, in somatic circulation, naked siRNAs are not only susceptible to degrade, but it is also difficult to realize the tumor cells’ internalization. Therefore, novel siRNA delivery vectors that could promote efficacy need to be developed urgently. Here, we designed high-surface gold nanostars (GNS-P) which are decorated with cationic tumor-targeting peptide as an efficient and functional siRNA delivery nanoplatform for tumor therapy. The positively charged amino acid sequence and huge surface area enabled the vector to load a large amount of siRNA, while the tumor-targeting peptide sequence and nano size enabled it to rapidly and precisely target the tumor regions for fast and effective siRNA delivery. This tumor-targeting nanoplatform, GNS-P, displayed good biocompatibility, low toxicity and an extraordinary tumor accumulation capability.

3D Printed biodegradable polymeric scaffolds are critical to repair a bone defect, which can provide the individual porous and network microenvironments for cell attachment and bone tissue regeneration. Biodegradable PCL/HA composites were prepared with the blending of poly(ε-caprolactone) (PCL) and hydroxyapatite nanoparticles (HA). Subsequently, the PCL/HA scaffolds were produced by the melting deposition-forming method using PCL/HA composites as the raw materials in this work. Through a serial of in vitro assessments, it was found that the PCL/HA composites possessed good biodegradability, low cell cytotoxicity, and good biocompatibility, which can improve the cell proliferation of osteoblast cells MC3T3-E1. Meanwhile, in vivo experiments were carried out for the rats with skull defects and rabbits with bone defects. It was observed that the PCL/HA scaffolds allowed the adhesion and penetration of bone cells, which enabled the growth of bone cells and bone tissue regeneration. With a composite design to load an anticancer drug (doxorubicin, DOX) and achieve sustained drug release performance, the multifunctional 3D printed PCL/HA/DOX scaffolds can enhance bone repair and be expected to inhibit probably the tumor cells after malignant bone tumor resection. Therefore, this work signifies that PCL/HA composites can be used as the potential biodegradable scaffolds for bone repairing.

An ideal positron emission tomography (PET) tracer should be highly extractable by the tumor tissue or organ that contains low toxicity and can provide high-resolution images in vivo. In this work, the aim was to evaluate the application of Al18 F-labeled 1,4,7-triazacyclononane-1,4,7-triacetic acid containing sulfonamide group (18 F-Al-NOTA-SN) as a potential tumor-targeting signal-enhanced radioactive tracer in PET. SN as a tumor-targeting group was incorporated to NOTA to make a ligand. Subsequently, this ligand reacted with Na18 F and AlCl3 to produce a compound 18 F-Al-NOTA-SN. This compound was further characterized and its property in regard to cell cytotoxicity assay, microPET imaging, biodistribution, cell uptake assay, and tumor selectivity in vitro and in vivo, was also investigated. 18 F-Al-NOTA-SN possessed low cell cytotoxicity and uptake to COS-7 and 293T healthy cells and high cell cytotoxicity and uptake to MDA-MB-231, HepG2, and HeLa tumor cells in vitro. Moreover, 18 F-Al-NOTA-SN showed good tumor-targeting property and high PET signal enhancement of HeLa tumors, liver, and kidneys in mice, as well as the uptake ratios of tumor to blood and tumor to muscle, were 4.98 and 3.87, respectively. 18 F-Al-NOTA-SN can be accepted to be kidney and liver eliminated earlier and show a potential tumor-targeting signal-enhanced radioactive tracer in PET.

In recent years, antibody-labeled fluorescent probes have attracted wide attention in fluorescence immunochromatography. Quantum dots (QDs) are excellent fluorescent materials with some unique optical properties, including strong stability against photobleaching, broad excitation spectra, high emission intensity, good fluorescence efficiency, and narrow excitonic emission. The CdSe/ZnS QDs microbeads were prepared by encapsulation in-situ of CdSe/ZnS QDs in polyisobornyl methacrylate (PIBOMA) herein and then functional QDs microbeads were produced by the binding of active carboxyl-modified QDs microbeads to the C-reactive protein (CRP) antibody. Their fluorescence properties were also investigated and functional QDs microbeads were further evaluated as fluorescent probes to detect different CRP concentrations using the fluorescence immunoassay test strips. The experiment data indicated that functional QDs microbeads possessed good stability, high fluorescence efficiencies, narrow fluorescence spectra, and good linear relationship of detection line signal versus quality inspection line signal (T1 / C) to the CRP concentration varying from 0.001 to 0.2 mg / l. Therefore, functional CdSe/ZnS QDs microbeads encapsulated in PIBOMA bioconjugated to CRP antibody can be used as the potential fluorescent probes to achieve quantitative detection in the immunochromatographic technology.

In this work, a cellular/intranuclear dual-targeting nanoplatform was designed for tumor photothermal therapy (PTT). As a photo-to-heat nanoheater, a gold nanostar (GNS) was decorated with a nuclear localization sequence (NLS) to form GNS-NLS which possessed nuclear-targeting ability. After that, hyaluronic acid (HA) was coated on the surface of GNS-NLS (GNS-NLS@HA) via electrostatic interaction for tumor cellular recognition and targeting. It was found that by harnessing the recognition of CD44 receptor by HA, GNS-NLS@HA had the ability to target tumor cells accurately, and further be efficaciously internalized into cells with stellate shape. Subsequently, tumor intracellular hyaluronidase (HAase) from the endosome led to the degradation of HA to expose nuclear-targeting nanoheater GNS-NLS, and GNS-NLS was able to enhance PTT efficiency through subcellular nuclear location by a dual-stage near infrared light irradiation strategy. The first stage of light irradiation was of short duration to enhance the subcellular location of the nanoplatform to nuclei, and the second stage of light irradiation was of long duration to achieve admirable photothermal transduction as well as destruction of nuclei. This cellular/intranuclear dual-targeting nanoplatform, GNS-NLS@HA, displayed prominent tumor suppression efficiency both in vitro and in vivo, and inhibited tumor metastasis effectively.

In recent decades, drug self-delivery systems (DSDSs) have appeared with extraordinary superiority for cancer therapy while realizing intracellular delivery without supererogatory drug carriers. Here, we have designed and programmed a novel self-delivery system to realize tumor targeting therapy. The amphiphilic proapoptotic peptide KLAKLAKKLAKLAKGCK(Fmoc)2 (KLA) was used to form a self-assembled structure (KD) by encapsulating the hydrophobic anticarcinogen doxorubicin (DOX). Then, tumor recognizing hyaluronic acid (HA) was coated on the surface of KD to obtain a tumor targeting self-delivery system (KDH). The protective layer of HA could protect the therapeutic agents from being inactivated during blood circulation, and further specifically recognize tumor cells by the CD44 receptor after KDH had located the tumor regions. Additionally, hyaluronidase (HAase) overexpressed in the endosome of tumor cells could degrade the protective layer of HA and accelerate the liberation of KLA and DOX. The proapoptotic peptide KLA had the ability to locate mitochondria and induce mitochondrial dysfunction; meanwhile the anticarcinogen DOX diffused to the nuclei to inhibit the growth of tumor cells. Both in vitro and in vivo studies identified that our self-delivery system KDH possessed precise tumor targeting, and exhibited fantastic antitumor efficacy as well as negligible side effects.

A highly luminescent three-dimensional terbium-based metal organic framework [Tb(cpia)(H2O)2]n·nH2O (1) has been employed for the selective detection of m-dinitroaromatics and Fe3+. Stability tests suggest that compound 1 exhibits good stability in hot water and acidic and basic conditions within the pH range of 4–13. The strong green emission of 1 could be efficiently quenched by 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,6-dinitrotoluene in ethanol. Significantly, compound 1 can also be used to detect 1,3-dinitrobenzene in aqueous phase with high sensitivity and low detection limit (1.89 μM), indicating the detection of m-dinitroaromatics in aqueous medium can be realized. Furthermore, compound 1 also exhibits superior luminescence quenching behavior towards Fe3+ with high sensitivity and selectivity among various metal cations. In addition, the luminescence quenching mechanisms towards different analytes are also discussed in detail. These results demonstrate that compound 1 is a promising luminescent sensor for the simultaneous selective detection of m-dinitroaromatics and Fe3+ in water.

Isoindoline nitroxide-containing porphyrins were synthesized by the reaction of 5-phenyldipyrromethane and 5-(4′-nitrophenyl)-dipyrromethane with 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl using the Lindsey method. These spin-labeled porphyrins were further characterized by MS, UV, FTIR, 1H-NMR, cyclic voltammetry, electron paramagnetic resonance (EPR), and fluorescence spectroscopy. The electrochemical assay demonstrated that these isoindoline nitroxides-containing porphyrins had similar electrochemical and redox properties as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl. Electron paramagnetic resonance test exhibited these porphyrins possessed the hyperfine splittings and characteristic spectra of isoindoline nitroxides, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. Fluorescence spectroscopy revealed that these porphyrins indicated fluorescence suppression characteristic of nitroxide–fluorophore systems. Moreover, their reduced isoindoline nitroxide-containing porphyrins eliminated the fluorescence suppression and displayed strong fluorescence. Thus, these isoindoline nitroxide-containing porphyrins may be considered as the potential fluorescent and EPR probes.

Novel functionalized carbon nanotubes (CNTs) were prepared by grafting disulfide-containing polyethyleneimine (SSPEI) to CNTs. The SSPEI were synthesized by Michael addition between cystamine bisacrylamide and low molecular weight branched 1.8 kDa PEI. Three SSPEI grafted carbon nanotubes (CNTs-SSPEI) were successfully prepared through grafting SSPEI to CNTs. The grafted ratios were 32.26%, 43.11%, and 51.50%, respectively. Moreover, the grafted ratio could be tuned by adjusting the CNTs/SSPEI ratio during the process of preparation. The CNTs-SSPEI was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The CNTs-SSPEI showed better dispersability and stability in water than CNTs. In addition, the SSPEI on the surface of CNTs-SSPEI could be degraded in the presence of dithiothreitol.

Although chemotherapy is the most common method in clinical therapeutics with a straightforward mechanism, conventional anti-tumor drugs are still almost incapable of preventing the occurrence of tumor metastasis. In this study, we developed a multi-functional drug delivery system EINP@DOX consisting of a tea-derived polyphenol EGCG, iron ions and DOX. The system integrated the functions of tumor inhibition, diagnosis and metastasis prevention to achieve a systematic tumor treatment. The nanoscale size of EINP@DOX facilitated its accumulation in tumor tissues by means of the enhanced permeability and retention (EPR) effect, and it was then transferred to endosomes. The weakly acidic microenvironment in the endosomes of the tumor cells could destroy the coordination structure of EINP@DOX to realize the release of DOX for tumor therapy. Furthermore, the dissociative EGCG played the role of an adjuvant to restrain EMT and down-regulate the MMP levels, which could prevent the occurrence of tumor metastasis. Meanwhile, iron ions as superior magnetic resonance imaging (MRI) contrast agents provided visual evidence for the accurate location of EINP@DOX. In vitro and in vivo studies demonstrated that EINP@DOX showed a remarkable performance in tumor diagnosis and excellent therapeutic efficacy, inhibiting the metastasis of tumor cells effectively at the same time.

Currently, fluorescent imaging is one of the most promising diagnostic approaches for facile detection of cancers in situ in thanks to a fluorescent probe. Two novel polypeptide-based fluorescent probes for different biomarkers to cancers are reported here. These probes focused on tyrosine-isoleucine-glycine-serine-arginine (YIGSR) and arginine-glycine-aspartic (RGD), which receptors play an important role in the extracellular matrix and are overexpressed in tumor cells and then can be used as tumor-targeting groups in fluorescent imaging. In this work, the pentpeptide-rhodamine B derivative (YIGSR-RhB) and tripeptide-rhodamine B derivative (RGD-RhB) were synthesized respectively by using the solid phase synthesis methods. These derivatives were further characterized by 1HNMR, MS, UV and IR, etc. Their fluorescent and biocompatibility properties, such as the cell cytotoxicity, cell uptake and fluorescent imaging of tumor cells, and fluorescent imaging in BALB/c female mice with 4T1 tumors and C57 mice with B16F10 tumor in vivo, were also measured. Experiment results demonstrated that YIGSR-RhB and RGD-RhB possessed the low cell cytotoxicity, good tumor-targeting property and fluorescent properties similar to rhodamine B. Moreover, YIGSR-RhB and RGD-RhB can be taken up highly by the B16F10 melanoma cells and 4T1 breast cancer cells, and then achieve the good fluorescent imaging in these tumor cells in vitro and tumors of mice in vivo. Therefore, YIGSR-RhB and RGD-RhB can be used as the potential tumor-targeting probes for fluorescent imaging. They can directly attach the cell membrane and specifically target to the tumor cells.

An ideal positron emission tomography (PET) tracer should be highly extractable by the tumor tissue or organ that contains low toxicity and can provide high-resolution images in vivo. In this work, the aim was to evaluate the application of Al

Polymeric nanoparticles (NPs) with two-photon (TP) activity were prepared by grafting a naphthalimide fluorophore onto poly(acrylic acid) to yield an amphiphilic polymer, which self-assembled in water. The NPs were characterized using various analytical techniques such as transmission electron microscopy, dynamic light scattering and spectroscopic measurements. The in vitro and in vivo biocompatibilities of the NPs were assessed by a cytotoxicity assay using HeLa cells and a feeding assay using Caenorhabditis elegans (C. elegans) as a small animal model, respectively. Finally, TP fluorescence imaging (FI) of living cells and C. elegans labelled with the NPs were observed by TP confocal microscopy. The experimental outcomes demonstrated that the NPs had sufficient water-dispersity and biocompatibility, had TP fluorescence activity, were resistant to pH variation and illumination, and were physically stable. TP FI revealed that the NPs could enter living cells and were primarily located in the cytoplasm. In addition, the NPs were ingested by C. elegans during the feeding process and were recognized and taken up by the active transport system of the intestinal cells. These findings indicated the feasibility of using the developed NPs as a nanolabel for TP FI. Moreover, with numerous modifiable carboxyl groups on its surface, the NPs could act as a platform to build multifunctional probes for potential applications in biosensing and assay labeling.

Poly(9-phenyl-2,4,8,10-tetraoxaspiro-[5,5]undcane-3-one) (PPTC) was synthesized by the microwave-assisted ring-opening polymerization (MROP) of a six-membered cyclic carbonate monomer 9-phenyl-2,4,8,10-tetraoxaspiro-[5,5]undcane-3-one (PTC) with tin(II) 2-ethylhexanoate (Sn(Oct)2) or aluminum isopropoxide (Al(OiPr)3) as the catalysts. The obtained polycarbonates were further reduced by apalladium/carbonate catalyst (10% Pd/C) to afford partly deprotected polycarbonates containing hydroxyl groups (HPPTC). These two types of polycarbonates were characterized by 1H-NMR, Fourier transform infrared spectroscopy (FTIR), UV, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and automatic contact-angle measurements. The influence of the feed molar ratio of monomer-to-catalyst, the microwave irradiation power and the reaction time on the polymerization was also studied. The experimental results showed that HPPTC possessed significantly higher hydrophilicity and water absorption rate than PPTC.

A water-soluble fullerenol containing porphyrin and isoindoline nitroxide groups APTSPP-C60(OH)10-(TMIO)3 was synthesized by the incorporation of 5-(4-amino-phenyl)-10,15,20-tris(4-sulfonatophenyl)-porphyrin (APTSPP) as a tumor-targeting group and 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl (FTMIO) into fullerenol C60(OH)11. This nonmaterial was further characterized by FT-IR, UV, MS, TEM, fluorescence, etc. and its properties in vitro were also evaluated. Electrochemical experiments indicated that APTSPP-C60(OH)10-(TMIO)3 retained similar electrochemical properties and redox reaction mechanisms as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO). Electron paramagnetic resonance (EPR) spectra of APTSPP-C60(OH)10-(TMIO)3 exhibited the hyperfine splittings and characteristic spectra of CTMIO, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. In vitro cytotoxicity assay showed APTSPP-C60(OH)10-(TMIO)3 possessed low cytotoxicities to human renal tubular e...

The high toxicity of chemical reducing agents for graphene oxide (GO) and the high-polluting emission of industrial waste lignin as black liquor are always the two troubling issues in clean production. Herein, we reported a sustainable win-win route to utilize waste lignin as a green reducing agent of GO through hydrothermal method. Various hydrothermal conditions were investigated to reveal the reduction capability and mechanism of lignin towards GO. Results indicated that lignin could repair the conjugated structure of GO, while the hydroxyl ions in water could cause the decarboxylation of GO. The lignin-reduced GO composites (LRGOs) prepared at acidic and neutral pHs tended to form hydrogels, while the alkaline LRGOs were monodispersed graphene nanosheets in water. The alkaline LRGO suspensions exhibited reversible sol-gel transition by adding acid/base, and irreversible gelation by metal ions chelation. Besides, they could self-assemble into a robust film with excellent mechanical properties (306.7 ± 47.9 MPa in tensile strength, 135.2 ± 45.3 GPa in modulus) and electrical conductivity (399.5 ± 58.3 S/cm) through vacuum filtration and annealing. The freeze-dried LRGO aerogels and their carbonized products showed excellent absorption capacities for various organic solvents. As electrode materials, the LRGO aerogels also displayed a high pseudo-capacitance of 213.8 F/g at 1 A/g. These findings of LRGOs showed a huge application potential in clean energy and environmental pollution treatment.

In this work, a hydrophilic naphthalimide-based fluorescence chemosensor (sensor 1) was synthesized for Cu2+ recognition, in which 2-(2-aminoethoxy)ethanol was introduced to improve the hydrophily and Schiff base acted as the multidentate ligand for Cu2+. The effect factors, sensing mechanism and regenerability of sensor 1 for Cu2+ sensing were systematically investigated. It was found that sensor 1 displayed a long emission wavelength of 532 nm upon excited in visible light region (436 nm), and the good water solubility made it utilized in aqueous media. It could selectively react with Cu2+ over other common metal ions to form a 2:1 complex within 1 min and result in significant fluorescence quench. The fluorescence change was linear to 0.5–10.0 μmol L−1 of Cu2+ with a low detection limit of 3.74 × 10−8 mol L−1. Sensor 1 has been successfully utilized for analyzing Cu2+ in water samples as well as imaging cellular Cu2+. Moreover, in view of fluorescence “on-off-on” switches of sensor 1 induced by Cu2+ and EDTA, an IMPLICATION logic gate was constructed based on fluorescence mode with Cu2+ and EDTA as inputs.

Folate-containing dextran ligand (FA-Dextran-DTPA) was synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and folate (FA) as a tumor-targeting group into dextran as a polymer carrier. This ligand was further reacted with gadolinium chloride to make a dextran gadolinium complex FA-Dextran-DTPA-Gd. The ligand and its gadolinium complex were characterized by 1H-NMR, FTIR, UV-Vis, average particle sizes and zeta potential, as well. In vitro properties including relaxivity, cytotoxicity assay, cellular uptake assay, and magnetic resonance imaging (MRI) were also evaluated. Compared with Gd-DTPA, FA-Dextran-DTPA-Gd possessed obviously higher relaxation effectiveness and lower cytotoxicity to HeLa cells. FA-Dextran-DTPA-Gd had a high affinity to the H460 and MDA-MB-231 tumor cells and can be taken up selectively by these tumor cells. Moreover, FA-Dextran-DTPA-Gd showed enhanced signal intensities (SI) of MRI and enhanced the contrast of MR images of tumor cells. These results indicated that FA-Dextran-DTPA-Gd showed the potential as a tumor-targeting contrast agent in MRI.

Polyetheretherketone (PEEK) is regarded as one of the most potential candidates of biomaterials in spinal implant applications. However, as a bioinert material, PEEK plays a limited role in osteoconduction and osseointegration. In this study, recombinant human bone morphogenetic protein-2 (rhBMP-2) was immobilized onto the surface of collagen-coated PEEK in order to prepare a multi-functional material. After adsorbed onto the PEEK surface by hydrophobic interaction, collagen was cross-linked with N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). EDC/NHS system also contributed to the immobilization of rhBMP-2. Water contact angle tests, XPS and SEM clearly demonstrated the surface changes. ELISA tests quantified the amount of rhBMP-2 immobilized and the release over a period of 30 d. In vitro evaluation proved that the osteogenesis differentiation rate was higher when cells were cultured on modified PEEK discs than on regular ones. In vivo tests were conducted and positive changes of major parameters were presented. This report demonstrates that the rhBMP-2 immobilized method for PEEK modification increase bioactivity in vitro and in vivo, suggesting its practicability in orthopedic and spinal clinical applications.

Purpose – The purpose of this investigation was to study a transparent coating based on organic silicone resins prepared by the hydrolysis and condensation of methyltriethoxysilane and tetraethoxysilane. Design/methodology/approach – The coating film was characterized by IR, UV, thermal gravity analysis, scanning electron microscope and an automatic contact angle meter. Some properties of the coating film, such as adhesion, impact resistance and wear-resistance also were evaluated. Findings – These uniform, clear and smooth coating films possessed the high transparent and light transmittance, high density, high hydrophobicity, good adhesion, hardness and anti-corrosion. Originality/value – The coating may be considered as a protective film for the surfaces of the metals and plastics.

Three fullerene isoindoline nitroxides N-methyl-3,4-fulleropyrrolidine-2-spiro-5′- (1′,1′,3′,3′-tetramethylisoindolin-2′-yloxyl), (C60-(TMIO)m, and C70-(TMIO)n) were synthesized by the covalent bonding of 5-formyl-1,1,3,3-tetramethyl isoindolin-2-yloxyl to the fullerenes C60 and C70. Significantly, the X-ray photoelectron spectra indicated the characteristic N 1s signals of NO. at 402 eV. The atomic force microscope morphologies showed that the average particle sizes of C60-(TMIO)m and C70-(TMIO)n were 38 and 15 nm. The electrochemical experiments indicated that fullerene bound isoindoline nitroxides retained similar electrochemical properties and redox reaction mechanisms as the parent nitroxides. The electron paramagnetic resonance spectra of the fullerene isoindoline nitroxides all exhibited the hyperfine splittings and characteristic spectra of tetramethyl isoindoline nitroxides, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. Therefore, these fullerene isoindoline...

An octadecyl silica hollow fiber (OSHF) was prepared by a template method. The characteristics of the OSHF were evaluated by scanning electron microscopy, elemental analysis and a pore size analyzer. It was an ideal material for solid phase microextraction. The performance of it was thus studied by extracting polycyclic aromatic hydrocarbons (PAHs) in water samples. The results demonstrated that under the optimal extraction conditions, the linearities were 0.6–60, 1–60 and 2–60 ng mL−1 for different PAHs with all regression coefficients higher than 0.976. The limits of detection were in the range of 31.5 to 97.9 pg mL−1 for these analytes.

Objective Gadolinium diethylenetriaminepentaacetic di[5-(4'-amidophenyl)-10,15,20- tris(4'-sulfonatophenyl) porphyrin trisodium salt] (Gd-DTPA-2APTSPP) was synthesized by the reaction of diethylenetriaminepentaacetic dianhydride with 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin and subsequently chelation with gadolium chloride. Methods This gadolinium complex was characterized and its properties in vitro and in vivo were also evaluated. Compared with Gd-DTPA, Gd-DTPA-2APTSPP possessed high relaxivity r1, low cytotoxicity to HeLa cells and high enhanced signal intensities of the VX2 carcinoma in rabbits for a prolonged time. Conclusion Moreover, Gd-DTPA-2APTSPP can distinguish the VX2 carcinoma from the reactive hyperplasia incited by inflammation and normal tissues in rabbits. Therefore, Gd-DTPA-2APTSPP can be taken up selectively by tumors and show the potential as a tumor-targeting MRI contrast agent.

Polyetheretherketone (PEEK) is regarded as one of the most potential candidates for replacing current implant applications. To obtain good bone-implant interfaces, many modification methods have been developed to enable PEEK and PEEK-based composites from bio-inert to bioactive. Among them, physical methods have aroused significant attention and been widely used to modify PEEK for orthopedic implants. This review summarizes current physical modification techniques of PEEK for orthopedic applications, which include composite strategies, surface coating methods and irradiation treatments. The positive consequences of those modification methods will encourage continuing investigations and stimulate the wide range of applications of PEEK-based implants in orthopedics.

Polycarbonate copolymers poly(trimethylene carbonate-co-5,5-dimethyl trimethylene carbonate) (PC, P(TMC-co-DTC)) was synthesized by the polymerization of trimethylene carbonate (TMC) and 5,5-dimethyl trimethylene carbonate (DTC) using Tin (II) 2-ethylhexanoate (Sn(Oct) 2 ) as a catalyst. The modified water-in-oil-in-water (w/o/w) solvent evaporation technique was adopted to produce anticancer magnetic polycarbonate microspheres TNF-PC-M containing human tumor necrosis factor-α (TNF) and Fe 3 O 4 magnetic ultrafine powders. The experiments evidenced that these magnetic polycarbonate microspheres had the strong magnetic responsiveness and high TNF loading concentration. Drug release studies showed that the microspheres sustained a steady release rate of TNF in PBS in vitro for up to 55 days. In vitro cytotoxicity assays demonstrated the microspheres had the high inhibition and anti-tumor action to human hepatocellular carcinoma (Bel-7204) cells in vitro. In vivo site-specific therapy in nude mice bearing Bel-7204 indicated that the microspheres possessed a markedly high antitumor activity.

Two kinds of cyclic aryl ester dimers have been synthesized by reaction of phthaloyl dichloride with bisphenols via interfacial polycondensation. The cyclic dimers readily undergo anionic ring-opening polymerization or copolymerization in the melt by using sodium benzoate as the initiator, producing linear, high molecular weight polyesters. The contents of cyclic dimers in the homopolymers P1, P2, and copolymer P12 are 13.7%, 10.2%, 2.9%, respectively, which indicates that ring-opening copolymerization of cyclic dimers may impel the conversion of cyclic dimers and decrease the content of cyclic dimers in the resulting copolymer. Moreover, the isothermal chemorheology of the ring-opening copolymerization of cyclic dimers indicates that the reactive molten mixture has low shear viscosity and the viscosity increases slowly in the initial stage of ring-opening polymerization.

Gadolinium diethylenetriamine-pentaacetic bisdopamide (Gd-DTPA-2DA) was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid (DTPA) and further reaction with gadolinium chloride. In vitro and in vivo properties were also evaluated. Gadolinium complex Gd-DTPA-2DA possessed higher relaxation effectiveness and less cytotoxicity to HeLa cells than that of Gd-DTPA. Moreover, Gd-DTPA-2DA greatly enhanced the contrast of MR images of the brains, provided prolonged intravascular duration, and produced highly contrasted visualization of the brain.

Water-soluble polyaspartamide isoindoline nitroxides 5-(4′-aminophenyl)-10,15,20-tris (4′-sulfonatophenyl) porphyrin, trisodium salt–poly[α,β- N-(2-hydroxyethyl)-l-aspartamide]–5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl were synthesized by the incorporation of 5-(4′-aminophenyl)-10,15,20-tris(4′-sulfonatophenyl) porphyrin, trisodium salt, as a tumor-targeting group, and 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl into poly[α,β- N-(2-hydroxyethyl)-l-aspartamide]. These compounds were characterized, and the in vitro properties were evaluated. The polyaspartamide isoindoline nitroxides had higher relaxation effectiveness and had greater toxicity to HeLa cells than that of 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl. The polyaspartamide isoindoline nitroxides retained similar electrochemical properties and redox reaction mechanisms as the parent nitroxides. The electron paramagnetic resonance spectra of polyaspartamide isoindoline nitroxides exhibited characteristic hyperfine electron paramagnetic resonance spectra of tetramethyl isoindoline nitroxides, with typical nitroxide g-values and nitrogen isotropic hyperfine coupling constants. Therefore, the water-soluble 5-(4′-aminophenyl)-10,15,20-tris(4′-sulfonatophenyl) porphyrin, trisodium salt–poly[α,β- N-(2-hydroxyethyl)-l-aspartamide]–5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl is considered to be a novel potential spin probe for electron paramagnetic resonance.

The polycarbonate copolymers poly[trimethylene carbonate-co-2-phenyl-5,5-bis(hydroxymethyl) trimethylene carbonate] [P(TMC-co-PTC)] were synthesized by the ring-opening polymerization of trimethylene carbonate (TMC) and 2-phenyl-5,5-bis(hydroxymethyl) trimethylene carbonate (PTC) with tin(II) 2-ethylhexanoate and aluminum isopropoxide as the catalysts. These copolymers were further reduced by a palladium/carbonate (Pd/C; 10%) catalyst to produce partly deprotected copolymers. These two types of copolymers were characterized by 1H-NMR, Fourier transform infrared spectroscopy, UV spectroscopy, gel permeation chromatography, differential scanning calorimetry, and an automatic contact angle meter. The influences of the feed molar ratio of the monomers, the catalyst concentration, the reaction time, and the reaction temperature on the copolymerization process were also studied. The copolymerization of the TMC and PTC monomers was a nonideal copolymerization, and the copolymerization reactivity ratio of TMC was higher than that of PTC. In vitro degradation tests indicated that the partly deprotected copolymers possessed faster degradation rates and more hydrophilicity than the corresponding unreduced copolymers. Moreover, the degradation of these two type copolymers increased when the pH value of the buffer solutions decreased. In vitro drug-release experiments showed that these two types of copolymers had steady drug-release rates and good controlled release properties. Moreover, the partly deprotected copolymers had faster drug-release rates than the corresponding unreduced copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A series of new spin-labeled porphyrin containing isoindoline nitroxide moieties were synthesized and characterized as potential free radical fluorescence sensors. Fluorescence-suppression was observed in the free-base monoradical porphyrins, whilst the free-base biradical porphyrins exhibited highly suppressed fluorescence about three times greater than the monoradical porphyrins. The observed fluorescence-suppression was attributed to enhanced intersystem crossing resulting from electronexchange between the doublet nitroxide and the excited porphyrin fluorophore. Notably, fluorescencesuppression was not as strong in the related metalated porphyrins, possibly due to insufficient spin coupling between the nitroxide and the porphyrin. Continuous wave EPR spectroscopy of the diradical porphyrins in fluid solution suggests that the nitroxyl-nitroxyl interspin distance is long enough and tumbling is fast enough not to detect dipolar coupling.

Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors.

The aim was to investigate anticancer drug-loaded poly(carbonate-ester) nanospheres as potential drug delivery systems for cancer therapy. Functional poly(carbonate-ester) copolymers (HPCP-SD) were synthesized by the incorporation of sulfadiazine as the tumor-targeting groups to hydroxyl groups of poly(carbonate-ester) copolymers. Two types of anticancer drug-loaded poly(carbonate-ester) nanospheres I and II were further prepared by dialysis method and high-voltage electrostatic field-assisted atomization, respectively, using HPCP-SD as polymeric carriers. These carriers and anticancer drug-loaded nanospheres were characterized, and their properties in vitro and in vivo were evaluated. These anticancer drug-loaded poly(carbonate-ester) nanospheres had steady drug release rates and good controlled release properties. Moreover, anticancer drug-loaded poly(carbonate-ester) nanospheres II had faster drug release rates than those of anticancer drug-loaded nanospheres I. These anticancer drug-loaded nanospheres possessed lower cytotoxicity to HEK 293 cells and exhibited obviously higher anticancer efficiencies to the HeLa tumor cells than that of 5-fluorouracil. Anticancer drug-loaded nanospheres I possessed lower cytotoxicity to HEK 293 cells and higher anticancer activity to HeLa cells than those of anticancer drug-loaded nanospheres II. These anticancer drug-loaded poly(carbonate-ester) nanospheres showed the potential as drug delivery systems for cancer therapy.

Magnetic resonance imaging (MRI) is a non-invasive clinical imaging modality, which has become widely used in the diagnosis of human diseases around the world. Some MRI exams include the use of contrast agents. The goal of an ideal MRI contrast agent involves the tissue- or organ-targeting materials with high relaxivity and specificity, low toxicity and side effects, suitable long intravascular duration and excretion time and high contrast enhancement with low doses, in vivo, all coupled to low overall cost. Dendrimers are synthetic, highly branched, mono-disperse macromolecules of nanometer dimensions. Properties associated with these dendrimers such as uniform size, water solubility, modifiable surface functionality and available internal cavities make them candidates for ideal carriers of MRI contrast agents. The research progress of the dendritic contrast agents is discussed.

Polystyrene/carbon nanotubes composites were readily prepared by reversed microemulsion polymerization. Compared with the composites prepared by solution mixing, the uniform dispersion of carbon nanotubes in polymer matrix could be obtained more easily and the thermal and electrical properties of the as-prepared composites were also enhanced. The as-prepared composites were deposited onto a microelectrode array to fabricate a vapor sensor. The response for different organic vapors was evaluated by monitoring the change in the resistance of the composites upon exposure to various gases. The change in resistance was of the order of about 103 for the composites prepared by reversed microemulsion polymerization. The chemical sensors based on the composites prepared by reversed microemulsion polymerization presented excellent reproducibility and reversibility in response. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011