Arrays of Bowl-Shaped Janus Particle Film with Structured Colors.

Structural colors generated via total internal reflection (TIR) using nanostructure-free micro-concave shapes have garnered increasing attention. However, the application of large micro-concave structures for structural coloration remains limited. Herein, a flexibly tunable structural color film fabricated by casting polydimethylsiloxane (PDMS) on an array of large poly(glycidyl methacrylate) (PGMA) bowl-shaped particles is reported. The resultant film exhibits tunable red to green structural colors with changing observation angles. Moreover, the color can be further tailored by altering the shape of the film itself. The incorporation of the PDMS layer not only facilitates a shift in the locus of TIR from the bottom surface to the top concave surface of the particles, thereby enabling the generation of structural color, but also confers enhanced flexibility to the film. Further decoration with silver nanoparticles imparts antimicrobial properties, yielding a novel antimicrobial coating material with structural colors. The simple and cost-effective strategy for the production of structural color films provides potential applications in antimicrobial coatings, enabling accessible and customizable structural coloration using big-size micro-concave particles.

Preparation of Poly(glycidyl methacrylate) (PGMA) and Amine Modified PGMA Adsorbents for Purification of Glucosinolates from Cruciferous Plants.

Glucosinolates (GLs) are of great interest for their potential as antioxidant and anticancer compounds. In this study, macroporous crosslinked copolymer adsorbents of poly (glycidyl methacrylate) (PGMA) and its amine (ethylenediamine, diethylamine, triethylamine)-modified derivatives were prepared and used to purify the GLS glucoerucin in a crude extract obtained from a cruciferous plant. These four adsorbents were evaluated by comparing their adsorption/desorption and decolorization performance for the purification of glucoerucin from crude plant extracts. According to the results, the strongly basic triethylamine modified PGMA (PGMA-III) adsorbent showed the best adsorption and desorption capacity of glucoerucin, and its adsorption data was a good fit to the Freundlich isotherm model and pseudo-second-order kinetics; the PGMA adsorbent gave the optimum decolorization performance. Furthermore, dynamic adsorption/desorption experiments were carried out to optimize the purification process. Two glass columns were serially connected and respectively wet-packed with PGMA and PGMA-III adsorbents so that glucoerucin could be decolorized and isolated from crude extracts in one process. Compared with KCl solution, aqueous ammonia was a preferable desorption solvent for the purification of glucoerucin and overcame the challenges of desalination efficiency, residual methanol and high operation costs. The results showed that after desorption with 10% aqueous ammonia, the purity of isolated glucoerucin was 74.39% with a recovery of 80.63%; after decolorization with PGMA adsorbent, the appearance of glucoerucin was improved and the purity increased by 11.30%. The process of using serially connected glass columns, wet-packed with PGMA and PGMA-III, may provide a simple, low-cost, and efficient method for the purification of GLs from cruciferous plants.

[Preparation technology comparison and performance evaluation of different protein A affinity chromatographic materials].

Protein A affinity chromatographic materials are widely used in clinical medicine and biomedicine because of their specific interactions with immunoglobulin G (IgG). Both the characteristics of the matrix, such as its structure and morphology, and the surface modification method contribute to the affinity properties of the packing materials. The specific, orderly, and oriented immobilization of protein A can reduce its steric hindrance with the matrix and preserve its bioactive sites. In this study, four types of affinity chromatographic materials were obtained using agarose and polyglycidyl methacrylate (PGMA) spheres as substrates, and multifunctional epoxy and maleimide groups were used to fix protein A. The effects of the ethylenediamine concentration, reaction pH, buffer concentration, and other conditions on the coupling efficiency of protein A and adsorption performance of IgG were evaluated. Multifunctional epoxy materials were prepared by converting part of the epoxy groups of the agarose and PGMA matrices into amino groups using 0.2 and 1.6 mol/L ethylenediamine, respectively. Protein A was coupled to the multifunctional epoxy materials using 5 mmol/L borate buffer (pH 8) as the reaction solution. When protein A was immobilized on the substrates by maleimide groups, the agarose and PGMA substrates were activated with 25% (v/v) ethylenediamine for 16 h to convert all epoxy groups into amino groups. The maleimide materials were then converted into amino-modified materials by adding 3 mg/mL 3-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) dissolved in dimethyl sulfoxide (DMSO) and then suspended in 5 mmol/L borate buffer (pH 8). The maleimide groups reacted specifically with the C-terminal of the sulfhydryl group of recombinant protein A to achieve highly selective fixation on both the agarose and PGMA substrates. The adsorption performance of the affinity materials for IgG was improved by optimizing the bonding conditions of protein A, such as the matrix type, matrix particle size, and protein A content, and the adsorption properties of each affinity material for IgG were determined. The column pressure of the protein A affinity materials prepared using agarose or PGMA as the matrix via the maleimide method was subsequently evaluated at different flow rates. The affinity materials prepared with PGMA as the matrix exhibited superior mechanical strength compared with the materials prepared with agarose. Moreover, an excellent linear relationship between the flow rate and column pressure of 80 mL/min was observed for this affinity material. Subsequently, the effect of the particle size of the PGMA matrix on the binding capacity of IgG was investigated. Under the same protein A content, the dynamic binding capacity of the affinity materials on the PGMA matrix was higher when the particle size was 44-88 µm than when other particle sizes were used. The properties of the affinity materials prepared using the multifunctional epoxy and maleimide-modified materials were compared by synthesizing affinity materials with different protein A coupling amounts of 1, 2, 4, 6, 8, and 10 mg/mL. The dynamic and static binding capacities of each material for bovine IgG were then determined. The prepared affinity material was packed into a chromatographic column to purify IgG from bovine colostrum. Although all materials showed specific adsorption selectivity for IgG, the affinity material prepared by immobilizing protein A on the PGMA matrix with maleimide showed significantly better performance and achieved a higher dynamic binding capacity at a lower protein grafting amount. When the protein grafting amount was 15.71 mg/mL, the dynamic binding capacity of bovine IgG was 32.23 mg/mL, and the dynamic binding capacity of human IgG reached 54.41 mg/mL. After 160 cycles of alkali treatment, the dynamic binding capacity of the material reached 94.6% of the initial value, indicating its good stability. The developed method is appropriate for the production of protein A affinity chromatographic materials and shows great potential in the fields of protein immobilization and immunoadsorption material synthesis.

Poly(glycidyl methacrylate) modified cellulose nanocrystals and their PBAT-based nanocomposites.

Melt processing of cellulose nanocrystals (CNCs) reinforced nanocomposites is still a serious challenge due to the hydrophilic nature of CNCs and their severe agglomeration tendency within the polymer melt. In this study, chemical modification of CNC through grafting poly(glycidyl methacrylate) (PGMA) with various degrees was implemented. Wettability of the modified CNCs (mCNCs) were controlled and their structure was characterized through Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), optical microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The nanocomposites of polybutylene adipate terephthalate (PBAT) with 3 wt% CNC and mCNC were prepared using an internal melt mixer. To differentiate the effects of CNC and PGMA molecules on the final properties of nanocomposites, PBAT/PGMA compounds were separately prepared. To confirm the chain characterization and molecular weight of the synthesized PGMAs, 1H NMR and gel permeation chromatography (GPC) analysis were conducted. Melt rheological analysis, dynamic mechanical analysis (DMA), DSC, and atomic force microscopy (AFM) were used to monitor the mCNC dispersion quality and the effect of PGMA modification in PBAT compounds. The results revealed that grafting CNC with longer PGMA considerably improved the CNCs' dispersion quality within PBAT. Such dispersion enhancement of long-chain mCNCs and interfacial interaction of PGMA and PBAT resulted in a noticeable increase in storage modulus and complex viscosity of the final nanocomposites.

Highly Adhesive Antimicrobial Coatings for External Fixation Devices.

Pin site infections arise from the use of percutaneous pinning techniques (as seen in skeletal traction, percutaneous fracture pinning, and external fixation for fracture stabilization or complex deformity reconstruction). These sites are niduses for infection because the skin barrier is disrupted, allowing for bacteria to enter a previously privileged area. After external fixation, the rate of pin site infections can reach up to 100%. Following pin site infection, the pin may loosen, causing increased pain (increasing narcotic usage) and decreasing the fixation of the fracture or deformity correction construct. More serious complications include osteomyelitis and deep tissue infections. Due to the morbidity and costs associated with its sequelae, strategies to reduce pin site infections are vital. Current strategies for preventing implant-associated infections include coatings with antibiotics, antimicrobial polymers and peptides, silver, and other antiseptics like chlorhexidine and silver-sulfadiazine. Problems facing the development of antimicrobial coatings on orthopedic implants and, specifically, on pins known as Kirschner wires (or K-wires) include poor adhesion of the drug-eluting layer, which is easily removed by shear forces during the implantation. Development of highly adhesive drug-eluting coatings could therefore lead to improved antimicrobial efficacy of these devices and ultimately reduce the burden of pin site infections. In response to this need, we developed two types of gel coatings: synthetic poly-glycidyl methacrylate-based and natural-chitosan-based. Upon drying, these gel coatings showed strong adhesion to pins and remained undamaged after the application of strong shear forces. We also demonstrated that antibiotics can be incorporated into these gels, and a K-wire with such a coating retained antimicrobial efficacy after drilling into and removal from a bone. Such a coating could be invaluable for K-wires and other orthopedic implants that experience strong shear forces during their implantation.

Synthesis of Thermo-Responsive Monofunctionalized Diblock Copolymer Worms.

Poly(glycerol monomethacrylate)-block-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA) with worm-like morphology is a typical example of reversible addition-fragmentation chain transfer (RAFT) dispersion polymerized thermo-responsive copolymer via polymerization-induced self-assembly (PISA) in aqueous solution. Chain transfer agents (CTAs) are the key component in controlling RAFT, the structures of which determine the end functional groups of the polymer chain. It is therefore of interest to monofunctionalize the polymers via CTA moiety, for bioactive functionality conjugation and in the meantime maintain the precisely controlled morphology of the copolymers and the related property. In this work, a newly designed CTA 5-(2-(tert-butoxycarbonylamino) ethylamino)-2-cyano-5-oxopentan-2-yl benzodithioate (t-Boc CPDB) was synthesized and used for the RAFT polymerization of PGMA45-PHPMA120. Subsequently, PGMA45-PHPMA120 copolymers with primary amine, maleimide, and reduced L-glutathione (a tripeptide) monofunctionalized terminals were synthesized via deprotection and conjugation reactions. These monofunctionalized copolymers maintain worm-like morphology and thermo-responsive property in aqueous solution (10% w/v), as confirmed by the transmission electron microscopy (TEM) images, and the observation of the phase transition behavior in between 4 °C and room temperature (~20 °C), respectively. Summarily, a range of thermo-responsive monofunctionalized PGMA45-PHPMA120 diblock copolymer worms were successfully synthesized, which are expected to offer potential biomedical applications, such as in polymer therapeutics, drug delivery, and diagnostics.

Synthesis of manganese-incorporated polycaplactone-poly (glyceryl methacrylate) theranostic smart hybrid polymersomes for efficient colon adenocarcinoma treatment.

In the current study, a multifunctional nanoscale vesicular system (polymersome) with the ability to accumulate in the site of action, control drug release and integrate diagnostic and therapeutic functions was developed. The theranostic polymersome was engineered as a promising dual-functional nanoplatform, which can be used for tumor therapy and magnetic resonance imaging (MRI). In this regard, the amphiphilic diblock copolymer of poly(ε-caprolactone)-block-poly(glyceryl methacrylate)[(PCL-b-PGMA)] was synthesized by combined ring-opening polymerization (ROP), and reversible addition-fragmentation chain-transfer (RAFT) polymerization techniques followed by hydrolysis of the pendant oxiran rings to hydroxyl groups. Because of the amphiphilic properties and desirable hydrophobic/hydrophilic balance of the synthesized copolymer, it could self-assemble to form a polymersomal structure in an aqueous environment (with diameters about 100-145 nm). The hydrophilic anticancer drug, doxorubicin (DOX) and hydrophobic paramagnetic Mn (phenanthroline)2 complex, being well-represented on T1-weighted magnetic resonance imaging (MRI), were encapsulated in the hydrophilic core (33%±2.3 efficiency) and hydrophobic bilayer membrane (100 %efficient) of a polymersome system, respectively to provide PCL-PGMA@Mn(phen)2/DOX NPs. It was found that adding aptamer AS1411 to NPs surfaces enhanced their specificity and selectivity towards colorectal cancer cells expressing nucleolin (HT29 and C26). In vivo evaluation after intravenous administration of the prepared platform was performed using subcutaneous C26 tumor-bearing Balb/C mice. The obtained results demonstrated that the prepared targeted platform provided a reduced systemic toxicity in terms of body weight loss and mortality while showing efficient tumor regression. Furthermore, the prepared theranostic platform afforded MRI imaging capability for tumor monitoring. It could be concluded that the biocompatible PCL-PGMA magnetic DOX-loaded polymersomes could serve as a versatile multifunctional system for simultaneous tumor imaging and therapy.

Synthesis, spectroscopic characterization, and in vitro antioxidant activity of polyglycidylmethacrylate/polyindole conducting polymer composites.

Polyglycidylmethacrylate/polyindole (PGMA/PIN) conducting polymer composites having five different compositions were prepared chemically using FeCl3 as an oxidant agent in chloroform solution and nitrogen atmosphere at 10°C. The conducting polymer composites were characterized by FTIR spectroscopic technique, scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA) measurements. It is seen that morphological structure of composite is different from PIN and PGMA. PGMA/PIN conducting polymer composite including 50% of PIN has a nonuniform and less homogenous structure compared to the PIN and PGMA polymer. in vitro antioxidant activity such as reduction force, superoxide radical removal activity, hydroxyl radical trapping activity, MDA measurements in Saccharomyces cerevisiae cells of PGMA/PIN conducting polymer composite was investigated. It was observed that the reduction force capacities decreased as PIN content and increased due to the percentage of composite of PGMA content. in vitro studies of synthesized composites have shown us that these compounds possess new antioxidant properties.

Comprehensive analysis of human IgG Fc N-glycopeptides and construction of a screening model for colorectal cancer.

Currently, analyzing intact glycopeptides remains a challengeable task. Considerable progress has been achieved in the knowledge of immunoglobulin G (IgG) glycans in patients with colorectal cancer (CRC), whereas data on IgG Fc N-glycopeptides are scarce in the literature. To fill this gap in knowledge, we developed a rapid and effective method to obtain and analyze IgG Fc N-glycopeptides in the plasma from 46 CRC patients and 67 healthy individuals using chitosan@poly (glycidyl methacrylate) @iminodiacetic acid (CS@PGMA@IDA) nanomaterial in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). A total of 29 N-glycopeptides were detected and analyzed. Compared with healthy individuals, CRC patients had increased levels of N-acteylglucosamine, yet decreased levels of galactosylation, fucosylation and sialylation. Further, a multivariate logistic regression model was developed using the levels of IgG Fc N-glycopeptides to distinguish CRC patients from healthy individuals, and the prediction performance was good, with an average AUC of the ROC curves of 0.893. SIGNIFICANCE: In this study, we proposed a strategy for obtaining and analyzing IgG glycopeptides using CS@PGMA@IDA nanomaterial in combination with MALDI-TOF-MS. Using this strategy, IgG Fc N-glycopeptides were analyzed in the plasma of CRC patients, and our findings indicated that glycosylation levels in the IgG Fc region were closely related to CRC. By using the IgG N-glycopeptide enrichment method and screening model designed in this study, early large-scale colorectal cancer screening can be implemented easily and fast.

Microscopic Structure of Swollen Hydrogels by Scanning Electron and Light Microscopies: Artifacts and Reality.

The exact knowledge of hydrogel microstructure, mainly its pore topology, is a key issue in hydrogel engineering. For visualization of the swollen hydrogels, the cryogenic or high vacuum scanning electron microscopies (cryo-SEM or HVSEM) are frequently used while the possibility of artifact-biased images is frequently underestimated. The major cause of artifacts is the formation of ice crystals upon freezing of the hydrated gel. Some porous hydrogels can be visualized with SEM without the danger of artifacts because the growing crystals are accommodated within already existing primary pores of the gel. In some non-porous hydrogels the secondary pores will also not be formed due to rigid network structure of gels that counteracts the crystal nucleation and growth. We have tested the limits of true reproduction of the hydrogel morphology imposed by the swelling degree and mechanical strength of gels by investigating a series of methacrylate hydrogels made by crosslinking polymerization of glycerol monomethacrylate and 2-hydroxyethyl methacrylate including their interpenetrating networks. The hydrogel morphology was studied using cryo-SEM, HVSEM, environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy (LSCM) and classical wide-field light microscopy (LM). The cryo-SEM and HVSEM yielded artifact-free micrographs for limited range of non-porous hydrogels and for macroporous gels. A true non-porous structure was observed free of artifacts only for hydrogels exhibiting relatively low swelling and high elastic modulus above 0.5 MPa, whereas for highly swollen and/or mechanically weak hydrogels the cryo-SEM/HVSEM experiments resulted in secondary porosity. In this contribution we present several cases of severe artifact formation in PHEMA and PGMA hydrogels during their visualization by cryo-SEM and HVSEM. We also put forward empirical correlation between hydrogel morphological and mechanical parameters and the occurrence and intensity of artifacts.

Inactivation of the pgmA Gene in Streptococcus mutans Significantly Decreases Biofilm-Associated Antimicrobial Tolerance.

Screening of a Streptococcus mutans mutant library indicated that pgmA mutants displayed a reduced biofilm-associated tolerance toward gentamicin. The biofilms formed by the S. mutans pgmA mutant also displayed decreased tolerance towards linezolid and vancomycin compared to wild-type biofilms. On the contrary, the resistance of planktonic S. mutans pgmA cells to gentamycin, linezolid, and vancomycin was more similar to wild-type levels. Investigations of biofilms grown in microtiter trays and on submerged glass slides showed that pgmA mutants formed roughly the same amount of biofilm as the wild type, indicating that the reduced antimicrobial tolerance of these mutants is not due to diminished biofilm formation. The pgmA gene product is known to be involved in the synthesis of precursors for cell wall components such as teichoic acids and membrane glycolipids. Accordingly, the S. mutans pgmA mutant showed increased sensitivity to Congo Red, indicating that it has impaired cell wall integrity. A changed cell wall composition of the S. mutans pgmA mutant may play a role in the increased sensitivity of S. mutans pgmA biofilms toward antibiotics.

Surface lattice resonance of line array of poly (glycidyl methacrylate) with CdS quantum dots for label-free biosensing.

One dimensional plasmonic grating is a kind of resonant electromagnetic wave absorber with a characteristic wavelength. This study focusses on one-dimensional plasmonic grating consisting of poly (glycidyl methacrylate) (PGMA) brushes and CdS quantum dots (CdQDs) fabrication and PGMA chains grafted on a primary substrate in a line array continued by the immobilization of biotin-modified CdQDs. PGMA brush line array (PBLA) of plasmonic grating exhibited an absorptance at 441 nm while at the same time, CdQDs immobilized with PBLA showed characteristic absorbance at 396 nm. The blue-shift from 441 nm matches the absorbance peak of biotin-modified CdQDs resulting in the enhancement of photoluminescence emission of CdQDs. With streptavidin incubation to assemble CdQDs at 50 nM, the significant decrease in grating height resulted in the red-shift of the absorbance peak to 536 nm. Due to the deviation in absorbance, the intensity of the PL emission decreased gradually with the increase in concentration of streptavidin. In addition, our results showed that streptavidin incubation altered the color reflected from the surface due to effective changes in the refractive index of the layer as well. The limit of detection of the grating for streptavidin detection was determined to be 50 nM. Thus, PBLA-CdQD has the potential to act as a highly-sensitive, label-free optical biosensor.

Coordination between Surface Lattice Resonances of Poly(glycidyl Methacrylate) Line Array and Surface Plasmon Resonances of CdS Quantum on Silicon Surface.

In this work, a unique hybrid system is proposed for one-dimensional gratings comprising of poly(glycidyl methacrylate) (PGMA) brushes and CdS quantum dots (CQDs). Generally, the emission of QDs is too weak to be observed in a dry state. Plasmonic resonances of the grating structures can be used to enhance the light emission or absorption of CQDs. The interaction between PGMA plasmonic nanostructures and inorganic CQDs plays a crucial role in engineering the light harvest, notably for optoelectronic applications. Extinction measurements of the hybrid system consisting of a PGMA grating and CQDs are reported. We designed one-dimensional gratings with various resolutions to tune the absorptance peaks of grating. PGMA grating grafted from a 1.5 µm resolution of trench arrays of photoresist exhibited absorptance peak at 395 nm, close to the absorption peak of CQDs, resulting in the photoluminescence enhancement of CQDs on the grating due to high charge carriers' recombination rate. Generally, the emission of quantum dots occurs under irradiation at characteristic wavelengths. Immobilizing QDs on the grating facilitates the emission of QDs under irradiation of full-wavelength light. Furthermore, the PGMA gratings with CQDs were immersed in various solvents to change the geometries resulting the shift of absorptance peak of grating. The proposed method could be applied for sensing the nature of the surrounding media and vice versa, as well as for various media of solvents.

Surface modification of polypropylene surgical meshes for improving adhesion with poloxamine hydrogel adhesive.

Tissue adhesive has notable clinical benefits in hernia repair fixation. A novel poloxamine tissue adhesive was previously shown to successfully bond collagen tissue with adequate adhesive strength. In application related to attachment of polypropylene (PP) mesh, the adhesive strength between the mesh and poloxamine hydrogel adhesive is limited by the hydrophobicity of PP monofilaments and lack of covalent bond formation. The purpose of this study was to compare two different surface modifications [bovine serum albumin (BSA) adsorption and poly-glycidyl methacrylate/human serum albumin (PGMA/HSA) grafting] of PP mesh for improving the adhesive strength between poloxamine hydrogel adhesive and PP mesh. The PGMA/HSA surface modification significantly improved the adhesive strength for meshes attached with poloxamine hydrogel tissue adhesive compared with unmodified meshes and meshes modified by BSA adsorption. An area of 1 cm2 adhesive provided for a maximum adhesive strength of 65-70 kPa for meshes modified by PGMA/HSA, 4-13 kPa for meshes modified by BSA, and 22-45 kPa for unmodified meshes. Optical microscopy and infrared spectroscopy (FTIR) confirmed the improved adhesive strength was achieved through mechanical interlock of the hydrogel tissue adhesive into the PP mesh pores and chemical bonding of the albumin after successful PGMA/HSA grafting onto the PP monofilaments. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1047-1055, 2019.

Design and fabrication of porous biodegradable scaffolds: a strategy for tissue engineering.

Current strategies of tissue engineering are focused on the reconstruction and regeneration of damaged or deformed tissues by grafting of cells with scaffolds and biomolecules. Recently, much interest is given to scaffolds which are based on mimic the extracellular matrix that have induced the formation of new tissues. To return functionality of the organ, the presence of a scaffold is essential as a matrix for cell colonization, migration, growth, differentiation and extracellular matrix deposition, until the tissues are totally restored or regenerated. A wide variety of approaches has been developed either in scaffold materials and production procedures or cell sources and cultivation techniques to regenerate the tissues/organs in tissue engineering applications. This study has been conducted to present an overview of the different scaffold fabrication techniques such as solvent casting and particulate leaching, electrospinning, emulsion freeze-drying, thermally induced phase separation, melt molding and rapid prototyping with their properties, limitations, theoretical principles and their prospective in tailoring appropriate micro-nanostructures for tissue regeneration applications. This review also includes discussion on recent works done in the field of tissue engineering.

Versatile Types of MRI-Visible Cationic Nanoparticles Involving Pullulan Polysaccharides for Multifunctional Gene Carriers.

Owing to the low cytotoxicity and excellent biocompatibility, polysaccharides are good candidates for the development of promising biomaterials. In this paper, a series of magnetic resonance imaging (MRI)-visible cationic polymeric nanoparticles involving liver cell-targeting polysaccharides were flexibly designed for multifunctional gene delivery systems. The pullulan-based vector (PuPGEA) consisting of one liver cell-targeting pullulan backbone and ethanolamine-functionalized poly(glycidyl methacrylate) (denoted by BUCT-PGEA) side chains with abundant hydroxyl units and secondary amine was first prepared by atom transfer radical polymerization. The resultant cationic nanoparticles (PuPGEA-GdL or PuPGEA-GdW) with MRI functions were produced accordingly by assembling PuPGEA with aminophenylboronic acid-modified Gd-DTPA (GdL) or GdW10O36(9-) (GdW) via the corresponding etherification or electrostatic interaction. The properties of the PuPGEA-GdL and PuPGEA-GdW nanoparticles including pDNA condensation ability, cytotoxicity, gene transfection, cellular uptake, and in vitro and in vivo MRI were characterized in details. Such kinds of cationic nanoparticles exhibited good performances in gene transfection in liver cells. PuPGEA-GdW demonstrated much better MRI abilities. The present design of PuPGEA-based cationic nanoparticles with the liver cell-targeting polysaccharides and MRI contrast agents would shed light on the exploration of tumor-targetable multifunctional gene delivery systems.

Well-defined reducible cationic nanogels based on functionalized low-molecular-weight PGMA for effective pDNA and siRNA delivery.

UNLABELLED: Nucleic acid-based gene therapy is a promising treatment option to cure numerous intractable diseases. For non-viral gene carriers, low-molecular-weight polymeric vectors generally demonstrate poor transfection performance, but benefit their final removals from the body. Recently, it was reported that aminated poly(glycidyl methacrylate) (PGMA) is one potential gene vector. Based on ethylenediamine (ED)-functionalized low-molecular-weight PGMA (denoted by PGED), a flexible strategy was herein proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with friendly crosslinking reagents for highly efficient nucleic acid delivery. α-Lipoic acid (LA), one natural antioxidant in human body, was readily introduced into ED-functionalized PGMA and crosslinked to produce cationic PGED-NGs with plentiful reducible lipoyl groups. PGED-NGs could effectively complex plasmid DNA (pDNA) and short interfering RNA (siRNA). Compared with pristine PGED, PGED-NGs exhibited much better performance of pDNA transfection. PGED-NGs also could efficiently transport MALAT1 siRNA (siR-M) into hepatoma cells and significantly suppressed the cancer cell proliferation and migration. The present work indicated that reducible cationic nanogels involving LA crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems. STATEMENT OF SIGNIFICANCE: Recently, the design of new types of high-performance nanoparticles is of great significance in delivering therapeutics. Nucleic acid-based therapy is a promising treatment option to cure numerous intractable diseases. A facile and straightforward strategy to fabricate safe nucleic acid delivery nanovectors is highly desirable. In this work, based on ethylenediamine-functionalized low-molecular-weight poly(glycidyl methacrylate), a flexible strategy was proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with α-Lipoic acid, one friendly crosslinking reagent, for highly efficient nucleic acid delivery. Such PGED-NGs possess plentiful reducible lipoyl groups, effectively encapsulated pDNA and siRNA and exhibited excellent abilities of nucleic acid delivery. The present work indicated that reducible cationic nanogels involving α-lipoic acid crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems.

Functional Reactive Polymer Electrospun Matrix.

Synthetic multifunctional electrospun composites are a new class of hybrid materials with many potential applications. However, the lack of an efficient, reactive large-area substrate has been one of the major limitations in the development of these materials as advanced functional platforms. Herein, we demonstrate the utility of electrospun poly(glycidyl methacrylate) films as a highly versatile platform for the development of functional nanostructured materials anchored to a surface. The utility of this platform as a reactive substrate is demonstrated by grafting poly(N-isopropylacrylamide) to incorporate stimuli-responsive properties. Additionally, we demonstrate that functional nanocomposites can be fabricated using this platform with properties for sensing, fluorescence imaging, and magneto-responsiveness.

Probe Intracellular Trafficking of a Polymeric DNA Delivery Vehicle by Functionalization with an Aggregation-Induced Emissive Tetraphenylethene Derivative.

Characteristic aggregation-induced quenching of π-fluorophores imposed substantial hindrance to their utilization in nanomedicine for insight into microscopic intracellular trafficking of therapeutic payload. To address this obstacle, we attempted to introduce a novel aggregation-induced emission (AIE) fluorophore into the cationic polymer, which was further used for formulation of a gene delivery carrier. Note that the selective restriction of the intramolecular rotation of the AIE fluorophore through its covalent bond to the polymer conduced to immense AIE. Furthermore, DNA payload labeled with the appropriate fluorophore as the Förster resonance energy transfer (FRET) acceptor verified a facile strategy to trace intracellular DNA releasing activity relying on the distance limitation requested by FRET (AIE fluorophore as FRET donor). Moreover, the hydrophobic nature of the AIE fluorophore appeared to promote colloidal stability of the constructed formulation. Together with other chemistry functionalization strategies (including endosome escape), the ultimate formulation exerted dramatic gene transfection efficiency. Hence, this report manifested a first nanomedicine platform combining AIE and FRET for microscopic insight into DNA intracellular trafficking activity.

Aggregation-Induced-Emissive Molecule Incorporated into Polymeric Nanoparticulate as FRET Donor for Observing Doxorubicin Delivery.

Tetraphenylethene (TPE) derivatives characterized with distinct aggregation-induced-emission, attempted to aggregate with doxorubicin (Dox) to formulate the interior compartment of polymeric nanoparticulate, served as fluorescence resonance energy transfer (FRET) donor to promote emission of acceptor Dox. Accordingly, this FRET formulation allowed identification of Dox in complexed form by detecting FRET. Important insight into the Dox releasing can be subsequently explored by extracting complexed Dox (FRET) from the overall Dox via direct single-photon excitation of Dox. Of note, functional catiomers were used to complex with FRET partners for a template formulation, which was verified to induce pH-responsive release in the targeted subcellular compartment. Hence, this well-defined multifunctional system entitles in situ observation of the drug releasing profile and insight on drug delivery journey from the tip of injection vein to the subcellular organelle of the targeted cells.