Preparation of water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups and their micelles behavior, anticoagulant effect and cytotoxicity

Ionic Hyperbranched Poly(amido-amine)-Incorporated Nanofiltration Membranes for High-Efficiency Dye Desalination

High-efficiency dye desalination is crucial in the textile industry, considering its importance for human health, safe aquatic ecological systems, and resource recovery. In order to solve the problem of effective separation of univalent salt and ionic dye under the condition of high salt, ionic hyperbranched poly(amido-amine) (HBPs) were synthesized based on a simple and scalable one-step polycondensation method and then incorporated into the polyamide (PA) selective layers to construct charged nanochannels through interfacial polymerization (IP) on the surface of a polyvinyl chloride ultrafiltration (PVC-UF) hollow fiber membrane. Both the internal nanopores of HBPs (internal nanochannels) and the interfacial voids between HBPs and the PA matrix (external nanochannels) can be regarded as a fast water molecule transport pathway, while the terminal ionic groups of ionic HBPs endow the nanochannels with charge characteristics for improving ionic dye/salt selectivities. The permeate fluxes and dye/salt selectivities of HBP-TAC/PIP (57.3 L m-2 h-1 and rhodamine B (RB)/NaCl selectivity of 224.0) and HBP-PS/PIP (63.7 L m-2 h-1 and lemon yellow (LY)/NaCl selectivity of 664.0) membranes under 0.4 MPa operation pressure are much higher than PIP-only and HBP-NH2/PIP membranes. At the same time, this project also studied the membrane desalination process in a simulated high-salinity dye/salt mixture system to provide a theoretical basis and technical support for the actual dye desalination process.

Enhanced hydrophilicity and anticoagulation of polysulfone materials modified via dihydroxypropyl, sulfonic groups and chitosan

A novel modified polysulfone (PSF) is successfully prepared for hemodialysis by grafting with a well-defined heparin-like polymer, sulfonated dihydroxypropyl chitosan (SDHPCS), which is obtained in proper sequence via alkalization of chitosan, etherification and sulfonation. PSF is modified via chloroacetyl chloride, and then, the chloroacylated polysulfone (CAPSF) with pristine PSF is transformed into CAPSF/PSF blend membrane via the phase inversion, followed introducing amino group into CAPSF on the surface and taking glutaraldehyde as bridge between modified PSF membrane and SDHPCS. The result of ¹H NMR spectrum of prepared CAPSF indicates that the degree of the substitution of chloroacetyl group. The SEM, EDS mapping, FTIR and XPS show that SDHPCS-g-PSF membranes are successfully prepared. The hydrophilicity of the membrane modified by SDHPCS is improved obviously, and the contact angle remarkably reduced from 87 ° to below 45°, exhibiting much better hydrophilicity. The hemocompatibility characterizations including BSA adsorption, Plasma recalcification time (PRT), hemolysis ratio (HR), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) also certificates that SDHPCS-g-PSF possesses lower BSA adsorption and enhanced blood compatibility.

Influence of nanoparticles on the haemostatic balance: between thrombosis and haemorrhage

Maintenance of a delicate haemostatic balance or a balance between clotting and bleeding is critical to human health. Irrespective of administration route, nanoparticles can reach the bloodstream and might interrupt the haemostatic balance by interfering with one or more components of the coagulation, anticoagulation, and fibrinolytic systems, which potentially lead to thrombosis or haemorrhage. However, inadequate understanding of their effects on the haemostatic balance, along with the fact that most studies mainly focus on the functionality of nanoparticles while forgetting or leaving behind their risk to the body's haemostatic balance, is a major concern. Hence, our review aims to provide a comprehensive depiction of nanoparticle-haemostatic balance interactions, which has not yet been covered. The synergistic roles of cells and plasma factors participating in haemostatic balance are presented. Possible interactions and interference of each type of nanoparticle with the haemostatic balance are comprehensively discussed, particularly focusing on the underlying mechanisms. Interactions of nanoparticles with innate immunity potentially linked to haemostasis are mentioned. Various physicochemical characteristics that influence the nanoparticle-haemostatic balance are detailed. Challenges and future directions are also proposed. This insight would be valuable for the establishment of nanoparticles that can either avoid unintended interference with the haemostatic balance or purposely downregulate/upregulate its key components in a controlled manner.

Ionic Dendrimer Based Polyamide Membranes for Ion Separation

Separating low/high-valent ions with sub-nanometer sizes is a crucial yet challenging task in various areas (e.g., within environmental, healthcare, chemical, and energy engineering). Satisfying high separation precision requires membranes with exceptionally high selectivity. One way to realize this is constructing well-designed ion-selective nanochannels in pressure-driven membranes where the separation mechanism relies on combined steric, dielectric exclusion, and Donnan effects. To this aim, charged nanochannels in polyamide (PA) membranes are created by incorporating ionic polyamidoamine (PAMAM) dendrimers via interfacial polymerization. Both sub-10 nm sizes of the ionic PAMAM dendrimer molecules and their gradient distributions in the PA nanofilms contribute to the successful formation of defect-free PA nanofilms, containing both internal (intramolecular voids) and external (interfacial voids between the ionic PAMAM dendrimers and the PA matrix) nanochannels for fast transport of water molecules. The external nanochannels with tunable ionizable groups endow the PA membranes with both high low/high-valent co-ion selectivity and chemical cleaning tolerance, while the ion sieving/transport mechanism was analyzed by employing the Donnan steric pore model with dielectric exclusion.

Weakly Ionically Bound Thermosensitive Hyperbranched Polymers

We synthesized novel amphiphilic hyperbranched polymers (HBPs) with variable contents of weakly ionically tethered thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) macrocations in contrast to traditional covalent linking. Their assembling behavior was studied below and above the lower critical solution temperature (LCST). The HBPs underwent a morphological transition under changing temperature and ionic strength due to the LCST transition of PNIPAM and the reduction in the ionization degree of terminal ionic groups, respectively. We suggest that, in contrast to traditional branched polymers, ionically linked PNIPAM macrocations can reversibly disassociate from the sulfonate groups and form mobile coronas, endowing the dynamic micellar morphologies. In addition, assembly at the air-water interface confined PNIPAM macrocations and resulted in the formation of heterogeneous Langmuir-Blodgett (LB) monolayers with diverse surface morphologies for different peripheral compositions with circular domains formed in the condensed state. The HBPs with 25% PNIPAM showed larger and more stable circular domains that were partially preserved at high compression than those of HBPs with 50% PNIPAM. Moreover, the LB monolayers showed variable surface mechanical and surface charge distribution, which can be attributed to net dipole redistribution caused by the behavior of mobile PNIPAM macrocations and core sulfonate groups.

Preparation of Functionalized Carbon-Coated Cobalt Nanoparticles with Sulfonated Arene Derivatives, a Study on Surface Functionalization and Stability

The functionalization of magnetic nanoparticles has been an important field in the last decade due to the versatile applications in catalysis and biomedicine. Generally, a high degree of functionalities on the surface of the nanoparticles is desired. In this study, covalent functionalization of various aromatic sulfonic acids on carbon-coated cobalt nanoparticles are investigated on surface functionalization yield and stability. The nanoparticles are prepared via covalent linkage of an in situ generated diazonium on the graphene-like surface. Adsorption and wash experiments were performed to confirm a covalent bonding of the naphthalene derivatives on the nanoparticle surface. With an increased number of sulfonic acid groups on the aromatic compound a significantly lower loading is observed on the corresponding functionalized nanoparticles. This can be counteracted by a change of nitrite species. With this method, nanoparticles with a high number of sulfonic acid groups can be produced.

Synthesis of highly branched water-soluble polyester and its surface sizing agent strengthening mechanism

Solvent-free and highly branched water-soluble polyester (WPET) is prepared through self-emulsification methodology, using dimethyl terephthalate (DMT), sodium dimethyl isophthalate-5-sulfonate (SIPM), trimethylolpropane (TMP), and ethylene glycol (EG) by the transesterification and polycondensation. The WPET were first utilized as surface-sizing agents for cellulose fiber paper. The structure, average molecular weights, and physical properties of the water-soluble polyester were characterized by FTIR, 1H NMR, gel permeation chromatography (GPC), dynamic light scattering (DLS), X-ray diffraction (XRD), and dynamic rheometer. The effects of polymer structure and properties, as well as the surface sizing of the paper, were investigated. WPET displayed better surface sizing properties when it was prepared under the following conditions: –COO/–OH molar ratio of 1:2, the SIPM content of 17.98%, and TMP content of 11.10%. The relationships between the WPET structure and sized paper were clearly illustrated. The mechanical properties and water resistance of sized paper did not only depend on multi-branched hydroxyl groups of the WPET chains but also relied on the interactions among polymers and fibers, as well as the high toughness of surface sizing agent. The sizing paper possesses excellent mechanical properties as well as water resistance.

Multiple Drug Delivery from Mesoporous Coating Realizing Combination Therapy for Bare Metal Stents

The simultaneous loading of multifunctional drugs has been regarded as one of the major challenges in the drug delivery system. Herein, a mesoporous silica coating was constructed on a bare metal stent surface by an evaporation-induced self-assembly method, in which both hydrophilic and hydrophobic drugs (heparin and rapamycin) were encapsulated by a one-pot method for the first time, and the release behaviors of these drugs were studied. The releasing mechanisms of these drugs were investigated in detail. Rapid release of heparin can achieve anticoagulation and endothelialization, whereas slow release of rapamycin can realize antiproliferative therapy for long term. In vitro hemocompatibility and promotion for proliferation of vein endothelial cells and the inhibition of smooth muscle cells were conducted. In vivo stent implantation results verify that the mesoporous silica coating with both heparin and rapamycin can successfully accelerate the endothelialization process and realize the antiproliferative therapy for as long as 3 months. These results indicate that this multifunctional mesoporous coating containing both hydrophilic and hydrophobic drugs might be a promising stent coating in the future.

One-step fabrication and characterization of Fe3O4/HBPE-DDSA/INH nanoparticles with controlled drug release for treatment of tuberculosis

In this study, Fe₃O₄/hyperbranched polyester-(2-dodecen-1-yl)succinic anhydride2-Dodecen-1-/isoniazid magnetic nanoparticles (Fe₃O₄/HBPE-DDSA/INH MNPs) with controlled drug release characteristics were synthesized successfully by a simple one-step method. Orthogonal experiments were performed to optimize the loading capacity and encapsulation efficiency of the MNPs. The structure of the Fe₃O₄/HBPE-DDSA/INH MNPs was characterized by ¹H nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization mass spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, and superconducting quantum interference device measurements, while their properties were characterized based on swelling behavior observations, in-vitro release experiments, and cytotoxicity analysis. The results indicated that the fabricated Fe₃O₄/HBPE-DDSA/INH MNPs had a high drug-loading capacity and encapsulation efficiency. Further, the drug-release rate of the MNPs was higher in an acidic buffer, indicating that the MNPs were pH-responsive. Swelling studies revealed that the MNPs exhibited diffusion-controlled drug release, while in-vitro release studies revealed that the drug-release properties could be controlled readily, owing to the high encapsulation efficiency of the MNPs and the uniform dispersion of the drug in them. These results collectively suggest that this multifunctional nontoxic drug delivery system, which exhibits good magnetic properties and pH-triggered drug-release characteristics, should be suitable for the treatment of tuberculosis.

Heparin mimetics with anticoagulant activity

Heparin, a sulfated polysaccharide belonging to the glycosaminoglycan family, has been widely used as an anticoagulant drug for decades and remains the most commonly used parenteral anticoagulant in adults and children. However, heparin has important clinical limitations and is derived from animal sources which pose significant safety and supply problems. The ever growing shortage of the raw material for heparin manufacturing may become a very significant issue in the future. These global limitations have prompted much research, especially following the recent well-publicized contamination scandal, into the development of alternative anticoagulants derived from non-animal and/or totally synthetic sources that mimic the structural features and properties of heparin. Such compounds, termed heparin mimetics, are also needed as anticoagulant materials for use in biomedical applications (e.g., stents, grafts, implants etc.). This review encompasses the development of heparin mimetics of various structural classes, including synthetic polymers and non-carbohydrate small molecules as well as sulfated oligo- and polysaccharides, and fondaparinux derivatives and conjugates, with a focus on developments in the past 10 years.

Superoxide Anion Biosensor Based on Bionic-Enzyme Hyperbranched Polyester Particles

Self-assembly techniques have been demonstrated to be a useful approach to developing new functional nanomaterials. In this study, a novel method to fabricate a manganese phosphate self-assembly monolayer (SAM) on a hyperbranched polyester (HBPE-OH) nanoparticle surface is described. First, the second-generation aliphatic HBPE-OH was carboxy-terminated, phosphorylated, and then ionized with manganese by a three-step modification process. The final product of HBPE-AMPA-Mn2+ particles was obtained and characterised by FT-IR spectroscopy, 1H NMR spectroscopy, transmission electron microscopy (TEM), Zeta potential, and energy dispersive spectroscopy (EDS). Moreover, the HBPE-AMPA-Mn2+ particles were used to construct a novel biosensor for detection of superoxide anions (O2•−) released from HeLa cells. Results showed that the response currents of this biosensor were proportional to the O2•− concentration ranging from 0.79 to 16.6 μM, and provided an extremely low detection limit of 0.026 μM (S/N = 3). The results indicate that the particle-decorated electrode surface, which involved a hyperbranched structure and a surface self-assembly technology, proposed here will offer the ideal catalytic system for electrochemical enzymatic sensors.

An aptasensor based on heparin-mimicking hyperbranched polyester with anti-biofouling interface for sensitive thrombin detection

In this paper, novel heparin-mimicking hyperbranched polyester nanoparticles (HBPE-SO₃ NPs) with abundant of sulfonated acid functional groups were synthesized, and their antithrombogenicities were further evaluated. Further, a label-free electrochemical aptamer biosensor (aptasensor) based on HBPE-SO₃ NPs modified electrode was developed for thrombin (TB) detection in whole blood. Meanwhile, the anti-biofouling properties of different modified electrodes were studied by whole blood and platelet adhesion test, hemolysis assay and morphological changes of red blood cells in vitro. Besides, the thrombin-binding aptamer was selected as receptor for the proposed aptasensor, which has excellent binding affinity and selectivity for TB. When binding to TB, the electron transfer taking place at the modified electrode interface was inhibited that can attribute to the stereo-hindrance effect, resulting in the decreased current response. This aptasensor showed excellent electrochemical properties with a wide detection range and a low detection limit of 0.031pM (S/N = 3), and provided high selectivity, long-term stability and good reproducibility. Finally, the sensitively detection of TB in whole blood samples directly was achieved by this aptasensor we proposed, which suggested its great potential for TB detection in the clinic.

Mesoporous Silica Nanoparticles-Encapsulated Agarose and Heparin as Anticoagulant and Resisting Bacterial Adhesion Coating for Biomedical Silicone

Silicone catheter has been widely used in peritoneal dialysis. The research missions of improving blood compatibility and the ability of resisting bacterial adhesion of silicone catheter have been implemented for the biomedical requirements. However, most of modification methods of surface modification were only able to develop the blood-contacting biomaterials with good hemocompatibility. It is difficult for the biomaterials to resist bacterial adhesion. Here, agarose was selected to resist bacterial adhesion, and heparin was chosen to improve hemocompatibility of materials. Both of them were loaded into mesoporous silica nanoparticles (MSNs), which were successfully modified on the silicone film surface via electrostatic interaction. Structures of the mesoporous coatings were characterized in detail by dynamic light scattering, transmission electron microscopy, Brunauer-Emmett-Teller surface area, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscope, and water contact angle. Platelet adhesion and aggregation, whole blood contact test, hemolysis and related morphology test of red blood cells, in vitro clotting time tests, and bacterial adhesion assay were performed to evaluate the anticoagulant effect and the ability of resisting bacterial adhesion of the modified silicone films. Results indicated that silicone films modified by MSNs had a good anticoagulant effect and could resist bacterial adhesion. The modified silicone films have potential as blood-contacting biomaterials that were attributed to their biomedical properties.

A surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat for selective removal of bilirubin

Electrospinning and surface molecular imprinting were used together to prepare a surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat for selective removal of bilirubin.

One-pot synthesis of indolizine functionalized nanohyperbranched polyesters with different nano morphologies and their fluorescent response to anthracene

Two nanohyperbranched polyesters of HBPE–CIDA₁ (nanospheres) and HBPE–CIDA₄ (nanospindles) were synthesized. The HBPE–CIDA₄ was established to be a fluorescent sensor for anthracene.

Recent advances in characterization of nonviral vectors for delivery of nucleic acids: impact on their biological performance

INTRODUCTION

Nucleic acid delivery is a complex process that requires transport across numerous extracellular and intracellular barriers, whose impact is often neglected during optimization studies. As such, the development of nonviral vectors for efficient delivery would benefit from an understanding of how these barriers relate to the physicochemical properties of lipoplexes and polyplexes.

AREAS COVERED

This review focuses on the evaluation of parameters associated with barriers to delivery such as blood and immune cells compatibility which, as a collective, may serve as a useful prescreening tool for the advancement of nonviral vectors in vivo. An outline of the most relevant rationally developed polyplexes and lipoplexes for clinical application is also given.

EXPERT OPINION

The evaluation of scientifically recognized parameters enabled the identification of systemic delivered nonviral vectors' behavior while in blood as one of the key determinants of vectors function and activity both in vitro and in vivo. This multiparametric approach complements the use of in vitro efficacy results alone for prescreening and improves in vitro-in vivo translation by minimizing false negatives. Further, it can aid in the identification of meaningful structure-function-activity relationships, improve the in vitro screening process of nonviral vectors before in vivo use and facilitate the future development of potent and safe nonviral vectors.

Hyperbranched polyester nanorods with pyrrolo[2,1-a]isoquinoline end groups for fluorescent recognition of Fe3+

Novel hyperbranched polyester nanorods HBPE-CICA₆ and HBPE-CICA₂ were obtained and used to establish a highly sensitive fluorescent sensor for Fe³⁺ ions.