Hyperbranched Polyethylenimine Research Articles

A simple and energy-saving route for the fabrication of superhydrophobic surfaces based on modified hyperbranched polyethyleneimine and nano silica

The facile and low-cost fabrication of fluorine-free superhydrophobic surfaces is still a challenge.

Cellulosic fabric treated with hyperbranched polyethyleneimine derivatives for improving antibacterial, dyeing, pH and thermo-responsive performance

Having cotton fabrics with multifunctional properties is of the most research focused on using either different processes or new and different materials. Improving thermo - responsive and antibacterial properties of cotton fabrics decorated with silver nanoparticles and nanogel has been investigated. During this research silver nanoparticles (AgNPs) have been in situ prepared using poly(N-isopropyl acrylamide)/polyethyleneimine microgel. Prepared particles have been characterized, visualized their morphological structure and their particle through microscopic analysis, which proved that their particle size was in range of (6–10 nm). The decorated gel with silver nanoparticles has been functionalized with silicone compounds to produce hybrid material. The produced gel has been characterized for its pH, temperature, textural, rheological, antimicrobial, cytotoxicity, and conductivity properties. The functional properties of the treated and untreated fabrics have been investigated, and the results proved that treated fabric has conductivity, antibacterial, pH and thermo-responsive properties.

Municipal Solid Waste as Secondary Resource: Selectively Separating Cu(II) from Highly Saline Fly Ash Extracts by Polymer-Assisted Ultrafiltration

Urban mining from fly ash resulting from municipal solid waste incineration (MSWI) is becoming more and more important due to the increasing scarcity of supply-critical metals. Metal extraction from acid fly ash leaching has already been established. In this context selective Cu recovery is still a challenge. Therefore, our purpose was the separation of Cu(II) from MSWI fly ash extracts by polymer-assisted ultrafiltration (PAUF). We investigated three polyethyleneimines (PEIs) with regard to metal retention, Cu(II) selectivity, Cu(II) loading capacity, and the viscosity of the PEI containing solutions. A demanding challenge was the highly complex matrix of the fly ash extracts, which contain up to 16 interfering metal ions in high concentrations and a chloride content of 60 g L−1. Overcoming that, Cu(II) was selectively enriched and separated from real fly ash extract at pH 3.0. At pH 1.0, a PEI-free Cu(II) concentrate was obtained and PEIs could be regenerated for reuse in further separation cycles. The PAUF conditions developed at laboratory scale were successfully transferred to pilot scale, and hyperbranched PEI (HB-PEI) was found to be the most suitable reagent for PAUF in a technical scale. Moreover, HB-PEI enables photometric control of the Cu(II) enrichment.

Water vapor dehumidification using thin-film nanocomposite membranes by the in situ formation of ultrasmall size iron-chelated nanoparticles

A facile in situ method by which to incorporate iron oxide nanoparticles (IONPs) entrapped by iron-chelated hyperbranched polyethyleneimine (HPEI) within a polyamide (PA) matrix was successfully applied to form thin film nanocomposite (TFN) membranes. The mechanism of the formation of Fe-HPEI-IONPs and their incorporation into the PA matrix are proposed. The performance of the membranes coated with Fe-HPEI-IONP-TMC combination underwent a mixed water vapor test with N2 gas with different operating parameters. Additionally, the effect of operating time on relative humity and the antibacterial properties were studied. The TFN membranes showed a significant improvement in the membranes Fe-HPEI-IONP content, hydrophilicity, and roughness, providing evidence of their outstanding performance as compared to pristine and thin film composite (TFC) membranes. The best performance of membranes achieved by water vapor/N2 permeation was a water vapor permeance value of 2093 GPU and a water vapor/N2 selectivity value of 1050 at a feed flow rate of 1 L/min and relative humidity of 70% for the M(40) TFN membrane with an iron chloride concentration of 40% with respect to HPEI. Moreover, the M(40) TFN membrane showed excellent anti-biofouling performance as compared to pristine PSf and TFC membranes, likely due to the biocidal effect of IONPs and Fe(III) ions toward E coli.

Graphene Oxide‐Hyperbranched Polyethyleneimine Fabricated and Stabilized AuNPs Nanocomposites for Colorimetric Detection of Silver Ions Based on a Non‐Aggregation Mechanism

AbstractHighly water‐soluble GO‐HPEI was prepared by modifying graphene oxide (GO) with hyperbranched polyethylenimine (HPEI) containing a large number of amines to solve the problem of poor water‐solubility of GO. Using GO‐HPEI as reducing agent and stabilizer, Au nanoparticles (AuNPs) based colorimetric probe (GO‐HPEI/AuNPs) with thermal stability up to 130 °C and high salt resistance was prepared in situ. The morphology and structure of GO‐HPEI/AuNPs were characterized by XPS, FTIR, TEM, DLS and Zeta potential. The GO‐HPEI/AuNPs can detect silver ions (Ag+) through the formation of non‐aggregated and stabilized Au−Ag core‐shell nanoparticles. The unusual sensing mechanism endowed this sensor with unique color variation and high selectivity. The GO‐HPEI/AuNPs sensor exhibited an obvious color change from red to ochre yellow and high sensitivity (LOD=54.9 nM) with a good linear relationship in the range of 0–65.7 μM (R2=0.9903). Furthermore, this colorimetric sensor was successfully applied to detect Ag+ in real water samples. Therefore, the GO‐HPEI/AuNPs sensor based on the formation of new nanomaterials has great potential for detecting Ag+ and analytical applications.

Efficient and Low Cytotoxicity Gene Carriers Based on Amine-Functionalized Polyvinylpyrrolidone.

Non-viral vectors are a safety tool for gene therapy to deliver therapeutic genes. Among the different non-viral vectors, polyvinylpyrrolidone (PVP), a well-known hydrosoluble, neutral, and non-toxic polymer, satisfies the requirements and becomes a suitable candidate for gene delivery. In this study, we describe the preparation of polyvinylpyrrolidones decorated with pyrrolidine, piperidine, and piperazine groups, and evaluate them in vitro as non-viral gene carriers. The properties of these new systems are compared with those of hyperbranched polyethyleneimine (PEI) used as a positive control. Their ability to complex DNA at different N/P molar ratios, from 1:1 up to 10:1, was studied through agarose gel electrophoresis and dynamic light scattering. The resulting complexes (polyplexes) were characterized and evaluated in vitro with murine fibroblast (Swiss 3T3) as non-viral gene carriers, using luciferase as the reporter gene and a calcein cytocompatibility assay. All the copolymers condensed DNA to a particle average size between 100–400 nm when used at N/P ratios of 4:1 or higher. The copolymers with piperidine groups showed higher transfection efficiency than the pyrrolidine and piperazine modified copolymers, and even higher than the positive control of PEI at N/P ratios of 4:1 or higher. All the synthesized polyplexes from an aminated PVP displayed a general tendency of high cytocompatibility (75–95%) in comparison with the positive control PEI (55%).

Incorporation of Core-Shell-Structured Zwitterionic Carbon Dots in Thin-Film Nanocomposite Membranes for Simultaneously Improved Perm-Selectivity and Antifouling Properties.

The development of highly efficient thin-film nanocomposite (TFN) membranes with superior water permeability, maintained rejection performance, and excellent antifouling capacity is critical to meeting the ever-escalating demand for fresh water. Herein, carbon dots (CDs) grafted with hyperbranched zwitterions, denoted as CDs-ZPEI0.6-10k, were first prepared by the hydrothermal treatment of citric acid in the presence of zwitterionic hyperbranched polyethylenimine (ZPEI0.6-10k) with different molecular weights (0.6, 1.8, and 10 kDa). Subsequently, the synthesized nanoparticles were introduced in membrane fabrication to form CDs-ZPEI0.6-10k-embedded TFN (TFN-CDs-ZPEI0.6-10k) membranes. The grafted shells of superhydrophilic ZPEI not only increased the chemical compatibility of CDs in the polyamide layer to suppress the formation of nonselective voids but also created a densely packed network for efficient water transportation and effective divalent salt rejection. The TFN-CDs-ZPEI10k membrane demonstrated a 2.8-fold enhancement in the permeate flux with an increased Na2SO4 rejection rate of 98.1% and improved antifouling properties than the pristine thin-film composite (TFC) membrane. This work provides an insight into the development of functionalized core-shell structured nanoparticles to effectively overcome the permeability-selectivity trade-off limitations and fouling problems in TFC membranes.

Selective adsorption of zwitterionic viscose fiber treated with sodium chloroacetate and hyperbranched polyethylenimine

Anionic modified viscose fiber (AVF) was prepared by using viscose fiber (VF) as raw material, sodium hydroxide as catalyst and sodium chloroacetate as modification reagent. The COOH content of anionic viscose fiber was 109.25 mmol/kg. Anionic viscose fibers were modified with branched polyethylenimine (HPEI) at 140 °C hydrothermal environment using a high-pressure reaction kettle. Zwitterionic viscose fibers (AVF-g-HPEI) with different amino and carboxyl contents could be obtained by changing the ratio of the two modified reagents. Increasing HPEI dosage resulted in amide group content of zwitterionic viscose fibers ranging from 0 to 108.35 mmol/kg. The zwitterionic viscose fibers were characterized by IR, SEM and XPS. IR analysis showed that zwitterionic viscose fiber was successfully prepared. SEM analysis showed that the reaction mainly occurred on the surface of the fiber, and the fiber structure was not changed. XPS analysis demonstrated that with the HPEI dosage increasing nitrogen elements on the surface of zwitterionic viscose fiber increased significantly. Dye adsorption experiments indicated that (1) AVF-g-HPEI could selectively adsorb the anionic dye or the cationic dye (such as methyl orange and methylene blue) from the mixed solution after the pre-treatment with pH 4.5 or pH 10.5 solution, respectively, (2) the dyes adsorbed by zwitterionic viscose fiber could be desorbed in the aqueous solution of pH 4.5 or 10.5, respectively and (3) the desorption ratio of AVF-g-HPEI remained above 0.85 after eight cycles.

Facile Method to Prepare pH-Sensitive PEI-Functionalized Carbon Nanotubes as Rationally Designed Vehicles for Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Delivery

A new pH-sensitive system designed for drug-delivery purposes and based on functionalized multiwall magnetic carbon nanotubes (Mag-CNTs) was synthesized for the effective incorporation of non-steroidal anti-inflammatory drugs (NSAIDs), aiming at drug release in characteristic acidic conditions close to the actual conditions of inflamed tissues. Cationic hyperbranched polyethyleneimine (PEI) was immobilized on the surface of Mag-CNTs via electrostatic interactions between the positively charged protonated amines within the polymer and the carboxyl groups on the chemically oxidized Mag-CNT surface. The addition of the NSAID with a carboxylate donor, Naproxen (NAP), was achieved by indirect coupling through the amino groups of the intermediate linker PEI. FT-IR, Raman, and UV–vis spectroscopy were employed to fully characterize the synthesized nanocarrier and its functionalization procedure. The interaction of the designed nanocarrier with bovine serum albumin (BSA) was studied in vitro by fluorescence emission spectroscopy while its in vitro interaction with calf-thymus (CT) DNA was monitored by UV–vis spectroscopy and viscosity measurements and via competitive studies with ethidium bromide. The calculated binding constants were compared to those of free NAP revealing a higher binding affinity for BSA and CT DNA. Finally, drug-release studies were performed, revealing that the electrostatic linkage ensures an effective release of the drug in the acidic pH typical of inflamed cells, while maintaining the multiwall nanotubes (MWNTs)–drug conjugates stable at the typical bloodstream.

Removal of Cd(II) from Water by HPEI Modified Humin

Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.

Improving the shale stability with nano-silica grafted with hyperbranched polyethyleneimine in water-based drilling fluid

Shale hydration and dispersion leading to wellbore instability is always a challenge in oil and gas drilling engineering. In this study, specifically designed nano-particles by grafting hyperbranched polyethyleneimine (Mw = 600) onto the surface of nano-silica particles were synthesized. The modified nano-particles were characterized with Fourier transform infrared spectrum (FT-IR), particles size distribution measurement, thermal gravimetric analysis (TGA), transmission electron microscope (TEM) and zeta potential measurement. The results indicated that after modification, the nano-particles became positively charged and showed better dispersion in water compared to pristine nano-silica particles. Shale cuttings hot-rolling dispersion test and linear swelling test as chemical inhibitive tests in combination with pressure transmission test and shale sample spontaneous imbibition test as physical plugging tests were used to evaluate the shale stabilizing performance of the modified nano-particles. The results showed that the modified nano-particles exhibited both effective chemical inhibition and physical plugging, whereas nano-silica only showed limited physical plugging. The interaction between modified nano-silica particles and shale demonstrated that the grafted hyperbranched polymer strongly adsorbed onto the clay surface via electrostatic interaction and hydrogen bonding, which resulted in effective inhibition of shale hydration and swelling. After adsorption, the modified nano-silica particles were trapped on the micropores of shale formation and prevented the fluid invasion. The dual functions of the modified nano-silica particles demonstrated a remarkable improvement of shale stability.

The Synthesis and Characterization of Novel Bi-/Trimetallic Nanoparticles and Their Nanocomposite Membranes for Envisaged Water Treatment.

The impact of worldwide water scarcity, further exacerbated by environmental pollution, necessitates the development of effective water treatment membranes. Herein, we report the synthesis and characterization of nanocomposite membranes containing hyperbranched polyethyleneimine (HPEI) stabilized bi-and trimetallic nanoparticles. These membranes were prepared by blending a pre-grafted Polyethersulfone (PES) powder with the Pd@Fe@HPEI and Pd@FeAg@HPEI nanoparticles followed by phase inversion. The membranes, together with stabilized nanoparticles, were characterized by several analytical techniques, such as attenuated total reflectance–Fourier transform infra-red spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), optical contact angle (OCA), scanning electron microscopy (SEM), atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HRTEM). These techniques revealed the elemental composition, zerovalent nature of the nanoparticles, and their small and even size distribution. Surface analysis showed chemical bonding between the polymeric functional groups and the supported nanoparticles. Furthermore, the nanocomposite membranes were found to be hydrophilic. Additionally, the membranes were investigated for swelling (water uptake), porosity, pore size, pure water permeation fluxes, and they indicated a decreased protein adhesion property. As such, the membranes fabricated in this work indicate the required properties for application in water treatment.

Fabrication of antifouling thin-film composite nanofiltration membrane via surface grafting of polyethyleneimine followed by zwitterionic modification

In this work, antifouling thin-film composite (TFC) nanofiltration (NF) membrane having zwitterionic PEI moieties was fabricated through the layer-by-layer interfacial polymerization (LbL-IP) via grafting hyperbranched polyethyleneimine (PEI) onto the polyamide surface, followed by in-situ N-methylation of PEI and then quaternization using 3-bromopropionic acid to form zwitterionic PEI. The successful surface modifications of TFC NF membrane with PEI and zwitterionic PEI were confirmed by XPS and ATR-FTIR results. Benefitting from the strong hydrophilicity and hyperbranched steric structure, the zwitterionic PEI-grafted TFC membrane (NF-ZPEI) exhibited a stronger hydration capacity and a thicker hydration layer than the PEI-grafted TFC membrane (NF-PEI) and the control sample (NF-PA). Meantime, the water permeability of NF-ZPEI membrane was enhanced by 11.6% higher than the control sample. The NF-ZPEI membrane also exhibited the improved ion selectivity of having a decreased rejection towards NaCl and maintaining a high rejection towards divalent ions. Dynamic fouling experiments were performed to demonstrate the impact of surface hydrophilicity and surface charge on the membrane fouling performances. Results illustrate that the zwitterionic PEI grafted on the TFC NF membrane mitigated the electrostatic attraction between the membrane surface and protein foulants, and exhibited the improved antifouling properties of having a low flux decline and a high flux recovery. Our work provides some insights on the zwitterionic surface modification of the TFC NF membrane with both the enhanced water permeability and the antifouling properties towards charged foulants.

Aminated electrospun nanofiber membrane as permeable reactive barrier material for effective in-situ Cr(VI) contaminated soil remediation

Electrokinetic remediation (EKR) combined permeable reactive barrier (PRB) is an emerging technique for the in-situ hexavalent chromium (Cr(VI)) heavy metal contaminated soil remediation. In the EKR-PRB technique, PRB materials with high Cr(VI) adsorption capacity and regenerability are severe desired. Here, a promising PRB material of aminated electrospun nanofiber membrane (ENFM) was synthesized by a facile short time thermal treatment of an hyperbranched polyethylenimine (HPEI)-enriched polyacrylonitrile (PAN) ENFM. The as-prepared PAN/HPEI ENFM exhibited a remarkable Cr(VI) adsorption capacity (~206 mg g−1) and excellent reusability (>9 cycles) owing to its amine group-rich membrane surface and interpenetrating porous structure. More importantly, a bench-scale Cr(VI) contaminated soil remediation test using a EKR-PRB technique showed that this PAN/HPEI ENFM could effectively immobilize and remove the Cr(VI) in soil.

A Conductive, Self-Healing Hybrid Hydrogel with Excellent Water-Retention and Thermal Stability by Introducing Ethylene Glycol as a Crystallization Inhibitor

The rapid development of flexible electronics motivates the design and synthesis of stable hydrogels that possess good stretchability and conductivity under harsh environment. The long-term durability of traditional hydrogels generally fails at high temperatures. In this work, a high-temperature-tolerant, self-healable hybrid hydrogel showing excellent water-locking and adhesive properties was developed through ultraviolet curing of acrylamide (AM) and hyper-branched polyethyleneimine (PEI) in highly salted ethylene glycol-water solution. Ethylene glycol was used as a crystallization inhibitor and greatly enhanced the solubility of sodium acetate (NaAc). The fabricated hydrogel can retain 75 % of its initial weight for 9 hours at 100 °C or 88 % of its initial weight for 77 hours at 15 % relative humidity (RH) environment. The dehydrated gel was flexible (tensile strain > 1700 %) and conductive after storing at high temperatures (e.g. 100 °C) for a long term. Moreover, the highly salted hydrogel showed remarkable water adsorbing ability in the air: it can recover to its original weight after losing water at high temperature or low humidity conditions. In addition, the separated hydrogel fragments could heal into a single piece in 30 s, and the hydrogel showed reversible adhesiveness to both organic (6.2 kPa for pigskin, 28 kPa for wood) and inorganic (111.9 kPa for glass, 135.5 kPa for iron) substances for at least 5 cycles. This work provides a facile way of obtaining multi-functional conductive hydrogels that can work at high temperatures, demonstrating long-term prospects in engineering applications.

Protoenzymes: The Case of Hyperbranched Polymer-Scaffolded ZnS Nanocrystals.

Enzymes are biological catalysts that are comprised of small-molecule, metal, or cluster catalysts augmented by biopolymeric scaffolds. It is conceivable that early in chemical evolution, ancestral enzymes opted for simpler, easier to assemble scaffolds. Herein, we describe such possible protoenzymes: hyperbranched polymer-scaffolded metal-sulfide nanocrystals. Hyperbranched polyethyleneimine (HyPEI) and glycerol citrate polymer-supported ZnS nanocrystals (NCs) are formed in a simple process. Transmission electron microscopy (TEM) analyses of HyPEI-supported NCs reveal spherical particles with an average size of 10 nm that undergo only a modest aggregation over a 14-day incubation. The polymer-supported ZnS NCs are shown to possess a high photocatalytic activity in an eosin B photodegradation assay, making them an attractive model for the study of the origin of life under the “Zn world” theory dominated by a photocatalytic proto-metabolic redox reaction network. The catalyst, however, could be easily adapted to apply broadly to different protoenzymatic systems.

An ultra-stretchable glycerol-ionic hybrid hydrogel with reversible gelid adhesion

Functional hydrogels have attracted enormous interest as wet adhesives for biomedical research and engineering applications. However, reversible hydrogel adhesives that can be used for gelid conditions were rarely reported. In this work, we have developed a freezing-tolerant (freezing temperature < −50 °C), ultra-stretchable (stretch strain > 30000% at 25 °C) glycerol-ionic hydrogel via the ultraviolet curing of acrylamide monomer and hyper-branched polyethylenimine polymer in CaCl2-water-glycerol solution. The fabricated hydrogel exhibited reversible gelid adhesion, rapid self-healing (recover in 3 s) and weight-retaining (>2 weeks) properties. The hydrogel allows two iron substrates to adhere together at −40 °C with the lap-shear adhesion strength as high as ~1 MPa. Such strong adhesion measured was reversible, specifically achieving ~100% of initial adhesion strength at 25 °C and ~36% at −40 °C. Additionally, decreasing the testing temperature significantly improved the tensile strength but decreased the fracture strain of the hydrogel. Interestingly, lap-shear adhesion tests suggested that the gelid adhesion strength was enhanced by 130 times as the testing temperature decreased from 25 °C to −40 °C, which was mainly attributed to the enhanced mechanical strength of the bulk hydrogel as well as the increased surface interaction at gel-substrate interfaces. More importantly, the adhesion failure gradually changed from cohesive failure to adhesive failure as the temperature decreased. This work provides new practical and fundamental insights into developing multifunctional freezing-tolerant hydrogel adhesive for gelid conditions.

Self-healable and biodegradable soy protein-based protective functional film with low cytotoxicity and high mechanical strength

Soy protein isolate (SPI) is a natural organic polymer, being used to prepare protective functional materials due to its sustainability, abundance, and easy processing. However, the protective effect of unmodified SPI films is significantly limited due to its poor mechanical properties, irreversible damage, and monotone functionality. Herein, high-flowability polyethyleneimine (PEI) was used to improve the dynamic properties of the protein matrix and cross-linking, and the phenolic hydrogen bonding of polydopamine (PDA) was used to develop a facile strategy for fabricating SPI-based films with satisfactory self-healing properties, high strength, excellent UV barrier performance, and remarkable fluorescence for the heavy metal detection. PEI disrupted the strong hydrogen bonds between protein molecules, causing them to be aggregated due to the PDA cross-linking. Thus, the phenols of PDA formed hydrogen bonds and constructed a reversible network, which endowed the SPI-PEI-PDA films with excellent self-healing properties. Because the hyperbranched PEI imparted the films with more cavities, the microcracks caused by external forces were blunted. Due to the further PDA crosslinking, the SPI-PEI-PDA films exhibited high mechanical strength. The SPI-PEI-PDA films also showed outstanding UV barrier performance and fluorescence properties for the heavy metal detection due to the bionic melanin-like characteristic of PDA andthe Michael addition reaction between the reactants. Additionally, SPI-PEI-PDA films demonstrated the low toxicity in vitro and in vivo, as well as the favorable biodegradability. These films improved the adaptability and safety of protective materials and could greatly promote functionalapplications of other biopolymer-based materials.

Ratiometric and sensitive cyanide sensing using dual-emissive gold nanoclusters.

The detection of cyanide anion (CN-), a highly toxic pollutant, has attracted growing attention in the past years. In this work, a nanosensor composed of hyperbranched polyethyleneimine (hPEI)-assisted dual-emissive gold nanoclusters (DE-Au NCs) is proposed for ratiometric detection of CN- based on surface valence state-driving etch. The ratiometric color change of fluorescence is based on a fact that the red-emissive Au NCs with a high content of surface Au(I) can be easily etched by CN-, while the blue-emissive Au NCs with nearly neutral character can resist CN-. Because of the specific gold-CN- chemistry and electrostatic attraction between the positively charged hPEI protecting layer and the negatively charged CN-, the DE-Au NC-based nanosensor provides high selectivity toward CN- over other anions with a limit of detection of 10nM. Practical application of the proposed DE-Au NC nanosensor is verified by satisfying recoveries of CN- determination in river water and urine samples. Graphical abstract.

Colloidal properties of self-assembled cationic hyperbranched-polyethyleneimine covered poly lactide-co-glycolide nanoparticles: Exploring modified release and cell delivery of methotrexate

This study explores the hypothesis that the colloidal properties of nanocarriers can modulate the interaction of hydrophilic and anionic chemotherapy agents with biological surfaces, especially tumoral cells. Different compositions were tested for preparing poloxamer-stabilized poly (lactic-co-glycolic acid) (PLGA) nanoparticles. Surface covering with the cationic hyperbranched polyethyleneimine (PEI) is tailored to improve methotrexate (MTX) efficacy against cancer cells. Two types of poloxamer (188 and 407) were tested as surfactants against different concentrations of PLGA in a nanoprecipitation method. Small and uniformly sized PLGA nanoparticles (90 to 110 nm) were produced with a neutral/slightly negative charge and low-drug loading efficiency. These limitations were resolved and improved by varying the PEI:PLGA ratio. The cationic-functionalized MTX-loaded nanoparticles showed a diameter of approximately 170 nm and a drug loading efficiency higher than 80%. The slow drug release profile was best fitted using the first order and the Peppas–Sahlin non-linear models. Fluorescence microscopy experiments reinforce the notion that drug uptake is improved using the functionalized nanoparticles. Cell viability assays reveal the biocompatibility of the drug-free cationic-functionalized nanoparticles and the increased efficacy of MTX-loaded cationic nanoparticles.