Hyperbranched Poly Amidoamine Research Articles

Micro-hydrogel Particles Consisting of Hyperbranched Polyamidoamine for the Removal of Heavy Metal Ions from Water

A series of micro-hydrogel particles consisting of hyperbranched polyamidoamine (HPAMAM) without any supporting core materials was synthesized via the inverse suspension condensation polymerization of A2 and B4 monomers, N,N′-methylenebisacrylamide (MBA) and ethylenediamine (EDA). The particles were found to be highly effective when used to remove heavy metal ions, such as cadmium, copper, lead, nickel, zinc, and cobalt, from water, and they could be separated from the water by a simple filtration process. The results of this study demonstrate that crosslinked HPAMAM particles, which can be prepared by a simple and environmentally friendly process, are an attractive absorbent for water purification.

Synthesis and anti-aging property in acrylonitrile-butadiene rubber of non-aromatic dendritic antioxidant with amine groups

ABSTRACTA novel kind of antioxidant with dendritic structure and amine groups for acrylonitrile-butadiene rubber (NBR) was synthesized via the combination of Michael addition and nucleophilic reactions. Structures of the synthesized non-aromatic dendritic antioxidants, namely first-generation (1.0 G), second-generation (2.0 G), third-generation (3.0 G) dendritic polyamidoamine (DPAMAM) and hyperbranched polyamidoamine (HPAMAM), were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H NMR). Anti-aging properties of the antioxidants for NBR vulcanizates were evaluated by accelerated thermal aging tests and extraction resistance tests. The decomposition of vulcanizates containing dendritic antioxidants were investigated by thermogravimetric (TGA) curves, and the thermo-oxidative aging kinetic parameters were calculated by the Dakin-Ozawa-Doyle (DOD) method. Compared with conventional aromatic antioxidant N-isopropyl-N′-phenyl-p-phenylene diamine (4010NA), the anti-aging properties of 1.0 G and 2.0 G DPAMAM were at the same level, while that of 3.0 G DPAMAM and HPAMAM were further improved. Meanwhile, HPAMAM and 3.0 G PAMAM showed better extraction resistance in NBR vulcanizates than 4010NA, thus indicating superior anti-aging performances. Maximum service temperatures (Tmax) under 30 years of service life span of NBR vulcanizates containing HPAMAM and 3.0 G DPAMAM were 219°C and 221°C, 15°C and 17°C higher than that of sample with 4010NA respectively.

Amino-terminated hyper-branched polyamidoamine polymer grafted magnetic graphene oxide nanosheets as an efficient sorbent for the extraction of selective serotonin reuptake inhibitors from plasma samples

In this study, third generation dendrimers covalently bonded to magnetic graphene oxide nanosheets (DMGO) were prepared.

Synthesis of a novel PEGDGA-coated hPAMAM complex as an efficient and biocompatible gene delivery vector: an in vitro and in vivo study

hPAMAM/DNA polyplexes, compared to viral vectors, display unique characteristics including more safety, less immune response outcomes, a simpler synthesis and an easier process. Given the importance of these polymers, hPAMAM coated with the PEGDGA copolymer was developed as a promising non-viral gene carrier. In the present study, a new complex of hPAMAM, PEGDGA-modified hyperbranched polyamidoamine (hPAMAM), was established as a versatile non-viral gene vector. The hPAMAM polymer was synthesized by using a modified one-pot method. The resulting hPAMAM–PEGDGA polymer was able to efficiently protect encapsulated-DNA against degradation for over 2 h. In addition to low cytotoxicity, the transfection efficiency of hPAMAM–PEGDGA represented much higher (p < 0.05) than that of Lipofectamine 2000 in both MCF7 and MDA-MB231 cells (an approximately 4.5-fold increase). Cellular uptake of hPAMAM–PEGDGA in MDA-MB231 cells, 254.79 ± 2.1, was significantly higher than that in MCF7 cells, 51.61 ± 6.1 (p < 0.05). EMA-labeled DNA can be clearly observed in the tumor tissue of mice receiving hPAMAM-PEGDGA/EMA-labeled DNA. However, a significant number of fluorescent spots can be found in the tumor tissue of mice receiving hPAMAM/DNA, when compared to those treated with naked hPAMAM/DNA. It has been observed that GFP is expressed more highly in hPAMAM-PEGDGA/EMA-labeled/DNA than the one in PAMAM/DNA. The results indicated that hPAMAM-PEGDGA-mediated gene delivery to breast cancer cells is a feasible and effective strategy that may offer a new therapeutic avenue as a non-viral gene delivery carrier. Notably, According to these findings, this newly-introduced copolymer, the hPAMAM–PEGDGA complex, has proved to be a promising strategy for drug or gene delivery to tissues or cell types of interest, particularly to triple-negative breast cancer.

Multiarm star poly(ɛ-caprolactone) with hyperbranched polyamidoamine as core capable of selective accommodating cationic or anionic guests

Hyperbranched polyamidoamines (HPAs) were directly employed as macroinitiators to initiate the Sn(Oct)2 catalyzed ring-opening polymerization of ɛ-caprolactone (CL), resulting in multiarm star copolymers with poly(ɛ-caprolactone) (PCL) as shells and HPA as core (HPA-b-PCL). From 1H-NMR characterization it was deduced that both the primary amines and the secondary amide groups of HPAs could initiate the CL polymerization, and the initiation efficiency increased when more CL monomers were fed. The average arm-numbers of the obtained stars were in the range of 115–353. Differential scanning calorimetry measurements demonstrated that the melting and crystallization temperatures, fusion and crystallization enthalpy and the degree of crystallinity of the star polymers increased as the PCL arm length increased. HPA-b-PCL stars could be used as nanocarriers to efficiently accommodate anionic dyes at acidic condition, while load cationic dyes at basic condition. Compared with the dye-loading behavior of multiarm star PCL with the neutral hyperbranched polyglycerol as core, it was deduced that HPA-b-PCL nanocarriers accommodated anionic dyes using the HPA core, while loaded cationic dyes using both the HPA core and the PCL shell. Dynamic light scattering analyses also supported such deduction. Furthermore, HPA-b-PCL nanocarriers could selectively load the anionic Eosin Y or the cationic methylene blue from their mixture at pH = 6 or 9, respectively, realizing their separation.

β-Cyclodextrin Modified Hybrid Magnetic Nanoparticles as an Adsorbent for Phenol Removal

β-cyclodextrin modified hybrid magnetic nanoparticles (Fe3O4@SiO2-h-PAMAM-CD) with a core-shell structure were prepared via the classic hyperbranched polyamidoamine synthesis method, the combination of Michael addition and aminolysis reaction, on the surfaces of silica coated iron oxide nanoparticles. The novel structure was confirmed by fourier transform infrared spectra (FT-IR), Transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), and the superior magnetic property was maintained and helped the material to separation and recycling. Further more, Fe3O4@SiO2-h-PAMAM-CD demonstrated excellent recycling and adsorption capacity for small molecule phenol in the aqueous solution.

The strategy to improve gene transfection efficiency and biocompatibility of hyperbranched PAMAM with the cooperation of PEGylated hyperbranched PAMAM

As a promising non-viral gene vector, cationic polyamidoamine (PAMAM) dendrimer could form complexes with negative charged DNA to mediate efficient gene delivery in vitro and in vivo. However, complicated synthesis technology and potential cytotoxicity limited their application in clinical translational researches. Hyperbranched polyamidoamine (h-PAMAM), which could be synthesized by a simpler one-pot method, has similar properties with PAMAM, and PEGylation modification of h-PAMAM has been used to reduce cytotoxicity. Here we prepared gene delivery system with h-PAMAM and h-PAMAM derivative h-PAMAM-g-PEG, respectively and found that the viability of cells with h-PAMAM-g-PEG was quite higher in comparison with cells with unmodified h-PAMAM. However, gene delivery efficiency was lower with h-PAMAM-g-PEG. Then we used mixture composed of h-PAMAM and h-PAMAM-g-PEG and such composition was designed to reduce cytotoxicity while maintaining high transfection efficiency. Our results indicated that this mixture system of h-PAMAM and h-PAMAM-g-PEG achieved higher transfection efficiency and lower cytotoxicity compared with h-PAMAM-only system.

Synthesis and characterization of Ni nanoparticles incorporated into hyperbranched polyamidoamine–polyvinylamine/SBA-15 catalyst for simple reduction of nitro aromatic compounds

In this study, hyperbranched polyamidoamine (PAMAM) was grown up onto the surface of polyvinyl amine-functionalized SBA-15 (PVAm/SBA-15) by a divergent method, without using organosilane precursors. Because of the surface modification of the PVAm/SBA-15 with the PAMAM hyperbranched polymer, the obtained hybrid material is able to trap water soluble metal ions such as Ni2+ via complex formation of PAMAM with metal ions. The reduction of trapped nickel ions in the hyperpolymeric shell of the PAMAM–PVAm/SBA-15 by sodium borohydride led to immobilized nickel nanoparticles in the structure of the composite. The obtained nanocomposite was effectively employed as a heterogeneous catalyst for the reduction of aromatic nitro compounds in the presence of NaBH4 as a reducing agent. The physical and chemical properties of the Ni nanoparticle-PAMAM–PVAm/SBA-15 were investigated by XRD, FT-IR, BET, TEM and XPS. The catalyst showed excellent activity for the reduction of a number of aromatic nitro compounds in water at room temperature and could be reused ten times without any significant loss of activity.

Synthesis, Characterization, and Drug Encapsulation of Hyperbranched Polyamidoamine Modified by β-Cyclodextrin

h-PAMAM-COOMe and its β-CD derivatives (h-PAMAM-CD) were synthesized step by step via the Michael addition and ester-aminolysis reaction from hyperbranched polyamidoamine (h-PAMAM). The structures of the as-prepared polymers were confirmed by Ubbelohde viscometer, FTIR, and 1H NMR. A series of inclusion complexation formed by β-naphtol in increasing h-PAMAM-β-CD with different concerntration were investigated by UV-vis spectrometer. The result showed that the novel hyperbranched polymer might have potential applications as delivery materials in chemotherapy.

Transplantation of novel vascular endothelial growth factor gene delivery system manipulated skeletal myoblasts promote myocardial repair

Skeletal myoblast (SkM) transplantation combined with vascular endothelial growth factor (VEGF) gene delivery has been proposed as a promising therapy for cardiac repair. Nevertheless, the defective gene vectors and unregulable VEGF expression in vivo hinder its application. Therefore, the search for an economical, effective, controllable gene delivery system is quite necessary. In our study, hyperbranched polyamidoamine (h-PAMAM) dendrimer was synthesized as a novel gene delivery vector using a modified method. And hypoxia-regulated human VEGF-165 plasmids (pHRE-hVEGF165) were constructed for controllable VEGF gene expression. The efficiency and feasibility of h-PAMAM-HRE-hVEGF165 gene delivery system manipulated SkM transplantation for cardiac repair were investigated in myocardial infarction models. The h-PAMAM encapsulated pHRE-hVEGF165 could resist nuclease digestion for over 120 min. In primary SkMs, h-PAMAM-pHRE-hVEGF165 gene delivery system showed high transfection efficiency (43.47 ± 2.22%) and minor cytotoxicity (cell viability = 91.38 ± 0.48%). And the transfected SkMs could express hVEGF165 for 18 days under hypoxia in vitro. For myocardial infarction models, intramyocardial transplantation of the transfected SkMs could result in reduction of apoptotic myocardiocytes, improvement of grafted cell survival, decrease of infarct size and interstitial fibrosis, and increase of blood vessel density, which inhibited left ventricle remodeling and improved heart function at the late phase following infarction. These results indicate that h-PAMAM based pHRE-hVEGF165 gene delivery into SkMs is feasible and effective, and may serve as a novel and promising gene therapy strategy in ischemic heart disease.

Adsorption of Pb(II) from aqueous solution by silica-gel supported hyperbranched polyamidoamine dendrimers

The adsorption properties of silica-gel supported hyperbranched polyamidoamine dendrimers (SiO2-G0–SiO2-G4.0) have been investigated by batch method. The effect of pH of the solution, contact time, initial Pb(II) ion concentration, temperature and coexisting metal ions have been demonstrated. The results indicated that the optimum pH value was 5. Adsorption kinetics was found to follow the pseudo-second-order model and controlled by film diffusion. The adsorption isotherms were fitted by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. Langmuir isotherm model was found to be more suitable to describe the equilibrium data, suggesting the uptake of Pb(II) ions by monolayer adsorption. From D–R isotherm model, the calculated mean free energy E demonstrated the adsorption processes occurred by chemical ion-exchange mechanism. FTIR analysis revealed that amine groups were mainly responsible for the adsorption of Pb(II) by amino-terminated adsorbents, while CO of ester groups also participated in the adsorption process of ester-terminated ones. The adsorbents can selectively adsorb Pb(II) from binary ion systems in the presence of Mn(II), Cu(II), Co(II), and Ni(II). Based on the results, it is concluded that SiO2-G0–SiO2-G4.0 had great potential for the removal of Pb(II) from aqueous solution.

Antimicrobial activity of CdS and Ag2S quantum dots immobilized on poly(amidoamine) grafted carbon nanotubes

Herein we report the design of antimicrobial nanohybrids, f-MWCNTs-CdS and f-MWCNTs-Ag2S developed by covalent grafting of cationic hyperbranched dendritic polyamidoamine (PAMAM) onto multiwalled carbon nanotubes (MWCNTs) and successive deposition of CdS and Ag2S quantum dots (QDs). The CdS and Ag2S QDs were in situ deposited on PAMAM grafted MWCNTs instead of anchoring the pre-synthesized QDs. The fourth generation, amine terminated hyperbranched PAMAM was grafted on MWCNTs, which was achieved through repetitive reactions of Michael addition of methylmethacrylate to the surface amino groups and amidation of terminal ester groups with ethylenediamine. The covalent grafting of PAMAM onto MWCNTs and the consecutive conjugation of CdS and Ag2S QDs were characterized using Fourier transform infrared spectroscopy, elemental analysis, powder X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive spectroscopy. The antibacterial activity of f-MWCNTs-CdS and f-MWCNTs-Ag2S nanohybrids was evaluated against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and the results were compared with the activity of carboxylated MWCNTs, PAMAM grafted MWCNTs, PAMAM dendrimer, and CdS and Ag2S QDs. It was found that the germicidal action of MWCNTs was enhanced by grafting of PAMAM, which was further improved with immobilization of CdS and Ag2S QDs.

Synthesis of thermoresponsive hyperbranched polyamidoamine and the molecular weight, pH, and anion sensitive thermoresponsive properties thereof

Hyperbranched polyamidoamine (HPAMAM) polymers, chemically analogous to the commercially available PAMAM dendrimer, were modified with isobutyric anhydride to result in isobutyramide (IBAm) terminated HPAMAMs (HPAMAM-IBAm). The aqueous solutions of HPAMAM-IBAm polymers had the lower critical solution temperature (LCST). The lower molecular-weight HPAMAM-IBAm exhibited higher LCST and the LCST difference was around 18 °C for one pseudo-generation variation. Further, the hyperbranched thermoresponsive polymers exhibited much lower LCSTs than the corresponding dendrimers with similar molecular weight. The LCST of HPAMAM-IBAm was pH sensitive. At pH below 10, the LCST increased significantly upon decreasing the pH, whereas, at pH above 10, the LCST decreased slowly with an increasing pH value. Nine sodium salts were used to measure the anion effect on the LCST of HPAMAM-IBAm. It was found that the LCST could also be modulated up or down in a broad range by simply adding a small amount of different kinds of inorganic anions. The specific ranking of inorganic anions in salting-out HPAMAM4-IBAm polymer was in accordance with the well-known Hofmeister series.

Novel hyperbranched polyamidoamine nanoparticle based gene delivery: Transfection, cytotoxicity and in vitro evaluation

In this study, hyperbranched polyamidoamine (hPAMAM) was developed as a novel non-viral gene vector for the first time. The hPAMAM was synthesized using a modified “one-pot” method. DNA was then bound to hPAMAM at different weight ratios (whPAMAM/wDNA). The higher weight ratio could bring larger particle size and higher zeta potential of hPAMAM–DNA complexes. The encapsulated DNA was protected by hPAMAM from degradation for over 3h. Under the optimal condition, high gene transfection efficiency could be achieved in COS7 (47.47±1.42%) and HEK293 (40.8±0.98%) cell lines. And hPAMAM showed rather minor cytotoxicity in vitro (cell viability=91.38±0.46% in COS7 and 92.38±0.61% in HEK293). The hPAMAM mediated human vascular endothelial growth factor 165 (hVEGF165) gene transfected cells could express hVEGF165 stably for 14 days, with the peak expression at day 2. In conclusion, hPAMAM based gene delivery was economical, effective and biocompatible, and may serve as a promising non-viral vehicle for gene therapy.

Novel hyperbranched polyamidoamine nanoparticles for transfecting skeletal myoblasts with vascular endothelial growth factor gene for cardiac repair

We investigated the feasibility and efficacy of hyperbranched polyamidoamine (hPAMAM) mediated human vascular endothelial growth factor-165 (hVEGF(165)) gene transfer into skeletal myoblasts for cardiac repair. The hPAMAM was synthesized using a modified one-pot method. Encapsulated DNA was protected by hPAMAM from degradation for over 120 min. The transfection efficiency of hPAMAM in myoblasts was 82.6 ± 7.0% with cell viability of 94.6 ± 1.4% under optimal conditions. The hPAMAM showed much higher transfection efficiency (P < 0.05) than polyetherimide and Lipofectamine 2000 with low cytotoxicity. The transfected skeletal myoblasts gave stable hVEGF(165) expression for 18 days. After transplantation of hPAMAM-hVEGF(165) transfected cells, apoptotic myocardial cells decreased at day 1 and heart function improved at day 28, with increased neovascularization (P < 0.05). These results indicate that hPAMAM-based gene delivery into myoblasts is feasible and effective and may serve as a novel and promising non-viral DNA vehicle for gene therapy in myocardial infarction.

Doubly Hydrophilic Multiarm Hyperbranched Polymers with Acylhydrazone Linkages as Acid‐Sensitive Drug Carriers

A novel type of drug carrier capable of controlled drug release is proposed. It consists of an acid-sensitive doubly hydrophilic multiarm hyperbranched copolymer with a hyperbranched polyamidoamine core and many linear poly(ethylene glycol) arms. Using pH-sensitive acylhydrazone linkages, the polymer forms unimolecular micelles that can encapsulate hydrophobic drugs. Due to their amphiphilicity, the drug-loaded unimolecular micelles can self-assemble into multimolecular micelles that show acid-triggered intracellular delivery of the hydrophobic drugs.

Hyperbranched Polymers for the Formation and Stabilization of ZnO Nanoparticles

The synthesis and characterization of a new family of dendritic polymers comprising a hyperbranched polyamidoamine core and polyethyleneglycol-derivative units is reported. The mentioned polymers have either core−shell or core−multishell architectures. Their intrinsic properties (solubility in a wide range of solvents, ability to interact with hydrophilic or hydrophobic compounds, etc.) allows the one-step in situ synthesis of water-soluble ZnO quantum dots via decomposition of an organometallic precursor. The effect of structural properties of the polymer (nature of the shell, core molecular weight, etc.), as well as external stimuli (temperature, ionic strength, etc.) on the formation and/or stabilization of nanoparticles has been evaluated. The as-synthesized nanoparticles could be easily redispersed in various solvents and presented stable photoluminescent properties.

A new two‐phase route to cadmium sulfide quantum dots using amphiphilic hyperbranched polymers as unimolecular nanoreactors

AbstractA new two‐phase route was developed to prepare monodisperse cadmium sulfide (CdS) quantum dots (QDs) with a narrow size distribution. In a two‐phase system, chloroform and water were used as separate solvents for palmitoyl chloride functionalized hyperbranched polyamidoamine (HPAMAM‐PC) and cadmium acetate/sodium sulfide, respectively. The amphiphilic HPAMAM‐PC, with a hydrophilic dendritic core and hydrophobic arms, formed stable unimolecular micelles in chloroform and was used to encapsulate aqueous Cd2+ ions. After the reaction with S2− ions from the aqueous phase, monodisperse and uniform‐sized CdS QDs stabilized by HPAMAM‐PC unimolecular micelles were obtained. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120:991–997, 2011

Chemical modification of chitosan with cationic hyperbranched dendritic polyamidoamine and its antimicrobial activity on cotton fabric

The cationic hyperbranched dendritic polyamidoamine (PAMAM) containing terminal methyl ester end groups was synthesized and then employed for modifying flake chitosan. The synthesis was achieved using repetitive reactions between Michael addition and amidation to obtain the methyl ester group terminated hyperbranched PAMAM, and then the methyl ester terminated hyperbranched dendritic PAMAM (PAMAM-ester) was methylated with dimethyl sulphate. The subsequent modification of chitosan with the cationic hyperbranched PAMAM-ester was carried out at room temperature for 5 days. As a result, cationic hyperbranched PAMAM modified chitosan was achieved. Characterizations by elemental analysis, FT-IR, NMR, TGA and XRD were employed to investigate the structural changes of chitosan to confirm its configuration. The cationic hyperbranched PAMAM-chitosan was applied onto cotton fabric at 1 wt.% add-on using a padding method and was found to have a good antimicrobial performance against Staphylococcus aureus compared to that obtained with unmodified chitosan.

Adsorption behaviors of Hg(II) on chitosan functionalized by amino-terminated hyperbranched polyamidoamine polymers

The adsorption behaviors of Hg(II) on adsorbents, chitosan functionalized by generation 1.0–3.0 of amino-terminated hyperbranched polyamidoamine polymers (denoted as CTS-1.0, CTS-2.0 and CTS-3.0, respectively), were studied. The optimum pH corresponding to the maximum adsorption capacities was found to be 5.0 for the three adsorbents. The experimental equilibrium data of Hg(II) on the three adsorbents were fitted to the Freundlich and the Langmuir models, and it is found that the Langmuir isotherm was the best fitting model to describe the equilibrium adsorption. The kinetics data indicated that the adsorption process of Hg(II) ions on CTS-1.0, CTS-2.0 and CTS-3.0 were governed by the film diffusion and followed pseudo-second-order rate model. Thermodynamic analysis and FTIR analysis revealed that the adsorption behaviors of Hg(II) ions on the three adsorbents could be considered as spontaneous, endothermic and chemical sorption process, resulting in their higher adsorption capacities at higher temperature.