Hyperbranched Aliphatic Polyester Research Articles

The influence of polycaprolactone content on the surface properties of polyurethane networks

AbstractThe aim of this work was to examine the influence of polycaprolactone (PCL) as a soft segment (SS) on the surface properties of polyurethane networks (PUNs). Five PUNs with different SS content (from 10 to 50 wt%) were prepared using Boltorn® aliphatic hyperbranched polyester of the second pseudo generation and isophorone diisocyanate as components of hard segments. The structure, hydrophobicity, wettability, and swelling behavior of these PUNs were investigated. Primarily, the obtained results showed that properties of prepared PUNs strongly depend on the content of SS that is, PCL. It has been established that the increase of SS content reduced the degree of hydrogen bonding in PUNs. Also, the increase of the SS content in PUNs induced appearance of more pronounced microphase separated morphology, better hydrophobicity and non‐wetting with diiodomethane. Simultaneously, the increase of the SS content led to the decrease of contact angles with formamide, and surface free energy of the prepared PUNs. These PUNs show good surface properties that are required for their potential application such as coatings.

Vancomycin-nanofunctionalized peptide-enriched silk fibroin to prevent methicillin-resistant Staphylococcus epidermidis-induced femoral nonunions in rats.

Implant-related infections and infected fractures are significant burdens in orthopedics. Staphylococcus epidermidis is one of the main causes of bone infections related to biofilm formation upon implants. Current antibiotic prophylaxis/therapy is often inadequate to prevent biofilm formation and results in antibiotic resistance. The development of bioactive materials combining antimicrobial and osteoconductive properties offers great potential for the eradication of microorganisms and for the enhancement of bone deposition in the presence of infections. The purpose of this study is to prevent the development of methicillin-resistant S. epidermidis (MRSE)-infected nonunion in a rat model. To this end, a recently developed in our laboratories bioactive material consisting of antibiotic-loaded nanoparticles based on carboxylic acid functionalized hyperbranched aliphatic polyester (CHAP) that are integrated into peptide-enriched silk fibroin sponges with osteoconductive properties (AFN-PSF) was employed, whose biocompatibility and microbiological tests provided proof of its potential for the treatment of both orthopedic and dental infections. In particular, non-critical femoral fractures fixed with plates and screws were performed in Wistar rats, which were then randomly divided into three groups: 1) the sham control (no infection, no treatment); 2) the control group, infected with MRSE and treated with peptide-enriched silk fibroin sponges incorporating non-drug-loaded functionalized nanoparticles (PSF); 3) the treated group, infected with MRSE and treated with peptide-enriched silk fibroin sponges incorporating vancomycin-loaded functionalized nanoparticles (AFN-PSF). After 8 weeks, bone healing and osteomyelitis were clinically assessed and evaluated by micro-CT, microbiological and histological analyses. The sham group showed no signs of infection and complete bone healing. The PSF group failed to repair the infected fracture, displaying 75% of altered bone healing and severe signs of osteomyelitis. The AFN-PSF treated group reached 70% of fracture healing in the absence of signs of osteomyelitis, such as abscesses in the cortical and intraosseous compartments and bone necrosis with sequestra. AFN-PSF sponges have proven effective in preventing the development of infected nonunion in vivo. The proposed nanotechnology for local administration of antibiotics can have a significant impact on patient health in the case of orthopedic infections.

Functionalized Hyperbranched Aliphatic Polyester Polyols: Synthesis, Properties and Applications

Functionalized Hyperbranched Aliphatic Polyester Polyols: Synthesis, Properties and Applications

Antibiotic-Loaded Hyperbranched Polyester Embedded into Peptide-Enriched Silk Fibroin for the Treatment of Orthopedic or Dental Infections.

The development of innovative osteoconductive matrices, which are enriched with antibiotic delivery nanosystems, has the invaluable potential to achieve both local contaminant eradication and the osseointegration of implanted devices. With the aim of producing safe, bioactive materials that have osteoconductive and antibacterial properties, novel, antibiotic-loaded, functionalized nanoparticles (AFN)—based on carboxylic acid functionalized hyperbranched aliphatic polyester (CHAP) that can be integrated into peptide-enriched silk fibroin (PSF) matrices with osteoconductive properties—were successfully synthesized. The obtained AFNPSF sponges were first physico-chemically characterized and then tested in vitro against eukaryotic cells and bacteria involved in orthopedic or oral infections. The biocompatibility and microbiological tests confirmed the promising characteristics of the AFN-PSF products for both orthopedic and dental applications. These preliminary results encourage the establishment of AFN-PSF-based preventative strategies in the fight against implant-related infections.

Studies on electrospun polyvinylidene fluoride/aliphatic hyperbranched polyester (Generation-1) blend based piezoelectric sensors

Since the last decade, many research groups are working towards improving the β-crystallinity in PVDF by blending with other polymers. In the present study, we have focused on the synthesis of aliphatic hyperbranched polyester of generation-1 (HBP-G1), solution-blending of PVDF with HBP-G1 (90:10 ratio), their electrospinning and piezoelectric measurements. From FTIR analysis of the electrospun samples, PVDF/HBP (90:10) sample was found to exhibit higher β-crystalline peak compared to neat PVDF. Further, the samples were used for fabricating piezoelectric sensors and measured for their peak-to-peak output voltage (Vp-p). Among them, PVDF/HBP-G1 (90:10) sample exhibited higher Vp-p (+1.76 V) compared to neat PVDF (100:0, +0.95 V). The data obtained from this study is evidence that the PVDF/HBP-G1 (90:10) based sensor can be efficiently used for energy-harvesting applications, which signifies the importance of this study.

Composition-property relationship of polyurethane networks based on polycaprolactone diol

This work was focused on the synthesis of polyurethane networks (PUNs) based on polycaprolactone (PCL) as soft segment (SS) and Boltorn® aliphatic hyperbranched polyester of the second pseudo generation and 4,4′-diphenylmethane diisocyanate (MDI) as the parts of the hard segments (HS), by a two-step solution polymerization. In order to find the best ratio between HS and SS to achieve good thermal and mechanical properties, suitable hydrophobicity and morphology of the PUNs, various experimental analyses were conducted. The obtained results revealed that features of the PUNs highly depend on the PCL content. The increase in the PCL content leads to the increase in thermal stability, hydrophobicity and appearance of the microphase separation, but on the other side, it also leads to the decrease in storage modulus in the rubbery plateau, crosslinking density and glass transition temperatures of PUNs. This work shows that features of PUNs can be easily adjusted for a specific application by careful selection of the SS and HS ratio.

RAFT Terminated Hyperbranched Functionalized Nano Rice Husk Powder / EPDM Nanocomposite for Biomedical Applications

ABSTRACT Modified nanosize rice husk powder (i.e. mod.nRHP; mod.nRHP-MA-RAFT-H)/ethylene propylene diene monomer (EPDM) nanocomposite was prepared by solvent casting method. The surface of nano rice husk (n-RHP) was treated with maleic anhydride (MA) to yield n-RHP-MA, then, aliphatic hyperbranched polyester (H) was end capped with RAFT agent to obtain H-RAFT. Afterward, H-RAFT-was successfully anchored onto nRHP-MA via RAFT polymerization technique to afford nRHP-MA-RAFT-H (mod.nRHP). The mechanical and thermal properties were studied for nRHP-MA-RAFT-H (mod.nRHP)/EPDM nanocomposite with different loadings of mod.nRHP. The cytotoxicity activities of the prepared mod.nRHP/EPDM nanocomposites were investigated toward human cell lines in vitro.

Polyurethane networks based on polycaprolactone and hyperbranched polyester: Structural, thermal and mechanical investigation

A series of environmentally friendly polyurethane (PU) networks based on polycaprolactone as soft segment (SS) and Boltorn® aliphatic hyperbranched polyester of the second pseudo generation as crosslinking agent was prepared by a two-step polymerization in solution. The chemical structure of the PU networks was analyzed by Fourier transform infrared spectroscopy, while XRD analysis revealed that these samples are amorphous. Swelling measurements, water absorption study, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, mechanical tests and scanning electron microscope revealed that, swelling behavior, hydrophobicity, thermal and mechanical features and morphology of PU networks show clear dependence on polycaprolactone content. The increase of the SS content induced appearance of the microphase separated morphology, increase of thermal stability, elongation at break, hydrophobicity and swelling ability in tetrahydrofuran and toluene, but at the same time it is responsible for the decrease of crosslinking density, glass transition temperatures, rigidity, tensile strength and Young’s modulus of PU networks. Scanning electron microscope images of the fracture surfaces of PU networks show that their surface is rough, irregular, with flake-like structure, where size of flakes increases with increasing SS content. These results indicate that by choosing adequate SS content, PU coatings with diverse features based on polycaprolactone and Boltorn® aliphatic hyperbranched polyester can be designed for appropriate and desired application.

Novel Chemical Cross-Linked Ionogel Based on Acrylate Terminated Hyperbranched Polymer with Superior Ionic Conductivity for High Performance Lithium-Ion Batteries.

A new family of chemical cross-linked ionogel is successfully synthesized by photopolymerization of hyperbranched aliphatic polyester with acrylate terminal groups in an ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4). The microstructure, viscoelastic behavior, mechanical property thermal stability, and ionic conductivities of the ionogels are investigated systematically. The ionogels exhibit high mechanical strength (up to 1.6 MPa) and high mechanical stability even at temperatures up to 200 °C. It is found to be thermally stable up to 371.3 °C and electrochemically stable above 4.3 V. The obtained ionogels show superior ionic conductivity over a wide temperature range (from 1.2 × 10−3 S cm−1 at 20 °C up to 5.0 × 10−2 S cm−1 at 120 °C). Moreover, the Li/LiFePO4 batteries based on ionogel electrolyte with LiBF4 show a higher specific capacity of 153.1 mAhg−1 and retain 98.1% after 100 cycles, exhibiting very stable charge/discharge behavior with good cycle performance. This work provides a new method for fabrication of novel advanced gel polymer electrolytes for applications in lithium-ion batteries.

Glyco-pseudodendrimers on a Polyester Basis: Synthesis and Investigation of Protein-Pseudodendrimer Interaction.

Molar mass and end group number of a hyperbranched polyester are significantly increased by its transformation to a pseudodendrimer. Three generations of pseudodendrimers are obtained from hyperbranched aliphatic polyester core by modification with a protected AB*2 monomer. A sequence of protection and deprotection steps leads to OH-terminated pseudodendrimers. NMR studies confirm maximum degree of branching in the first generation, which slightly decreases in the next two generations. Uniform, dense molecular structure formation was confirmed by MD simulation. Further modification to glyco-pseudodendrimers was performed with α-D-mannose leading to high molar masses and dense distribution of sugar units. The interaction of these sugar units with a plant lectin concanavalin A (Con A) was investigated using dynamic light scattering and cryogenic transmission electron microscopy. The protein-interaction studies of the glyco-pseudodendrimers confirm a loose network with Con A. The interaction activity depends on the generation number and modification degree.

Assembly of Amphiphilic Hyperbranched Polymeric Ionic Liquids in Aqueous Media at Different pH and Ionic Strength

We demonstrated the assembly of amphiphilic hyperbranched protic ionic liquids (HBP-ILs) based on aliphatic hyperbranched polyester (HBP) in aqueous media in a wide range of pH and ionic conditions. The series of new branched polyionic liquids with different terminal groups, HBP-ILs, was synthesized by neutralization of carboxylic and sulfonic terminal acid groups of hypebranched core with N-methylimidazole (Im) and 1,2,4-1H-triazole (Tr). HBP-IL compounds with triazole and imidazole counterions form 12–16 nm core–corona micelles at pH 11.6. We found that the introduction of long hydrophobic terminal groups such as n-octadecylurethane tails to initial hydrophobic HBP core has larger effect on the size of micellar assemblies than the introduction of ionic terminals groups. Furthermore, tuning the hydrophilic/hydrophobic balance of HBP-ILs can be achieved by changing the degree of ionization of terminal groups and counterions by reducing pH from 11.6 to 5.2 or ionic strength to 0.1 M. These changes caused t...

Development of novel electrically conductive scaffold based on hyperbranched polyester and polythiophene for tissue engineering applications.

A novel electrically conductive scaffold containing hyperbranched aliphatic polyester (HAP), polythiophene (PTh), and poly(ε-caprolactone) (PCL) for regenerative medicine application was succesfully fabricated via electrospinning technique. For this purpose, the HAP (G4; fourth generation) was synthesized via melt polycondensation reaction from tris(methylol)propane and 2,2-bis(methylol)propionic acid (bis-MPA). Afterward, the synthesized HAP was functionalized with 2-thiopheneacetic acid in the presence of N,N-dicyclohexyl carbodiimide, and N-hydroxysuccinimide as coupling agent and catalyst, respectively, to afford a thiophene-functionalized G4 macromonomer. This macromonomer was subsequently used in chemical oxidation copolymerization with thiophene monomer to produce a star-shaped PTh with G4 core (G4-PTh). The solution of the G4-PTh, and PCL was electrospun to produce uniform, conductive, and biocompatible nanofibers. The conductivity, hydrophilicity, and mechanical properties of these nanofibers were investigated. The biocompatibility of the electrospun nanofibers were evaluated by assessing the adhesion and proliferation of mouse osteoblast MC3T3-E1 cell line and in vitro degradability to demonstrate their potential uses as a tissue engineering scaffold. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2673-2684, 2016.

Phase equilibria in binary systems formed by a hyperbranched aliphatic polyester and alcohols

Hyperbranched polymers (HBPs) possess unique properties that make them interesting for use in a wide variety of applications. Examples are their potential use in separation processes such as distillation and solvent extraction. The design of the separation process demands a thorough knowledge of the phase behaviour in systems composed of HBPs and common organic solvents. This contribution reports on the phase behaviour in binary systems formed by the hyperbranched polyester H3200 and alcohols. Both liquid–liquid and solid–liquid equilibria were investigated. It was shown that a small amount of water present in these systems has a significant impact on the extent of the liquid–liquid phase split. At temperatures below 325 K alcohol solutions of H3200 form gels over a wide concentration range of the polymer. It seems that in these systems gelation results from arrested phase instability.

Abstract P5-03-02: The dynamic duo: A breast cancer-targeting nanoparticle loaded with a cytotoxic peptide as a treatment for metastatic disease

Abstract Metastatic breast cancer is a uniformly fatal disease with a 5-year survival rate of 15 percent. To date there are no effective approaches for targeted therapy. To develop a treatment for metastatic cancer, our group discovered a novel cytotoxic peptide, CT20p, and developed a nanotechnology-based platform to deliver and concentrate CT20p in breast tumors. CT20p was derived from Bax, a member of the Bcl-2 family. Unlike the parent protein, CT20p does not cause apoptosis and its cytotoxicity is independent of caspases and Bcl-2 overexpression. Rather, the intracellular target of CT20p is a protein called chaperonin-containing T-complex (CCT), which is required for the folding of actin and tubulin into their native forms. Inhibition of CCT activity by CT20p, indicated by decreased F-actin and tubulin, impaired the polymerization of microfilaments and microtubules, causing loss of cell migration and adhesion that promoted breast cancer cell death. In contrast, normal, non-transformed cells were resistant to the cytotoxicity of CT20p. On its own, CT20p is not membrane-permeable. To deliver the peptide to cells, we used nanoparticles formed with a novel aliphatic hyperbranched polyester polymer (HBPE-NPs). The surface of HBPE-NPs retains carboxylic acid groups for labeling of targeting ligands to enable accumulation in tumors. To concentrate on breast cancer, we functionalized the HBPE-NPs with either folate (FOL) or glutamate (GLU), which target the folate receptor (FR) or the metabotropic glutamate receptor (GRM-1) respectively. FR and GRM-2 are essential metabolic components that are highly expressed in solid tumors like breast cancer. In vitro targeting studies using triple negative breast cancer cell (TNBC) lines established that folate FOL or GLU-HBPE-NPs loaded with fluorescent dyes were readily up taken at high efficiency by TNBC cells. HBPE-NPs also contain unique hydrophobic cavities especially suited for encapsulating CT20p. We found that once the CT20p-HBPE-NPs were taken up by cancer cells, the peptide was released inside cells under acidic conditions (e.g. endosomes) and directly interacted with its intracellular target, CCT. Studies using primary cells derived from human breast tumors confirmed the targeted uptake of HBPE-NPs as well as demonstrated the cancer-specific cytotoxicity of CT20p. We treated a murine TNBC xenograft model with nanomolar amounts of FOL-CT20p-HBPE-NPs and achieved 100% regression of established tumors as well as prevented tumor growth. These studies indicated that CT20p is a potent and specific anti-cancer agent due to its inhibition of CCT, an essential molecular complex highly expressed in cancer cells, and that the peptide can be efficiently delivered to tumor sites using HBPE-NPs decorated with ligands to receptors, such FR or GRM-1, found on tumor cells. Citation Format: Vishnubhotla P, Khaled AR, Khaled AS, Perez JM, Bassiouni R, Flores O, Nierenberg D. The dynamic duo: A breast cancer-targeting nanoparticle loaded with a cytotoxic peptide as a treatment for metastatic disease. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-03-02.

Novel three-dimensional, conducting, biocompatible, porous, and elastic polyaniline-based scaffolds for regenerative therapies

Fabrication of two novel three-dimensional, conducting, biocompatible, porous, and elastic scaffolds composed of hyperbranched aliphatic polyesters, polyaniline, and poly(ε-caprolactone) for tissue engineering applications.

Waterborne Sustainable Tough Hyperbranched Aliphatic Polyester Thermosets

A waterborne polymer is a greener alternative than a solvent borne one because of its nontoxicity and nonflammability nature as well as it does not need any organic solvent. Thus, three biodegradable waterborne hyperbranched aliphatic polyesters were synthesized from citric acid, poly(ethylene glycol), glycerol and 2,2-bis(hydroxyl methyl) propionic acid, by a polycondensation reaction without using any additional catalyst or neutralizing agent. The structures of these polyesters were elucidated from spectroscopic analyses. Degrees of branching of the polymers were evaluated from 13C NMR spectra and found to vary from 0.59 to 0.70. Thermoset of these polyesters was obtained by curing of a formulation composed of waterborne hyperbranched polyester (57.1%), hyperbranched epoxy (28.87%) and poly(amidoamine) (14.28%) using water as a solvent with a little amount of THF as a cosolvent. The performance characteristics such as tensile strength (4.0–7.8 MPa), elongation at break (175–245%), toughness (655–1742 MPa), impact resistance (>1 m), gloss (89–96), scratch resistance (3–4 kg) and chemical resistance (good) of the thermosets were evaluated. The results clearly revealed the profound influence of citric acid content on performance of such polyester thermosets. These polyester thermosets were found to be highly biodegradable by Pseudomonas aeruginosa and Bacillus subtilis bacterial strains and also exhibited hemocompatibilty. Therefore, the citric acid based sustainable tough hyperbranched polyester thermosets with acceptable performance were obtained through a facile and environmentally benign route.

Preparation, characterization and performance study of cellulose acetate membranes modified by aliphatic hyperbranched polyester

Two generations of aliphatic hyperbranched polyester (HBPE) were synthesized from 2,2-bis(methylol)propionic acid and 1,1,1-trihydroxymethyl propane (TMP) as the core moiety by melt condensation method and were blended with cellulose acetate to prepare asymmetric membrane using a phase inversion process. Characterization of the prepared membranes for thermal behavior and morphological studies also has been made using TGA, DSC and SEM techniques. Water contact angle, pure water flux, water content, hydraulic resistance and molecular weight cut-off determinations were applied in order to study of filtration properties and surface and bulk hydrophilicity of the membranes. FTIR/ATR and contact angle results proved existence of (HBPE) on the surface of modified membranes and (FE-SEM) images have good correlation with flux and MWCOs. The result shows that, the surface hydrophilicity of membranes incorporating HBPE is much higher than pure CA or even (PEG-600) modified CA membranes. Furthermore, results show CA-HBPE membranes have lower flux and MWCOs, higher hydraulic resistance and better thermal and mechanical properties in comparison to the membranes modified by linear pore-forming agent.

A simple and general method for the determination of content of terminal groups in hyperbranched polymers derived from ABn monomers

In this contribution, we focused on the analysis of the topological structure of hyperbranched polymers derived from ABn (n ≥ 2) monomers. It was proved that the content of terminal groups (CT) in hyperbranched polymers only depended on the number of B functional groups in ABn monomers (n) and molar mass of linear unit of A0B(n − 1)(MA0B(n − 1)), regardless of the degree of branching. The CT of the hyperbranched polymers can be determined according to a simple expression: CT = (n − 1)/MA0B(n − 1). This formula method was verified to be a simple and reliable approach, as compared to the traditional NMR or titration methods, to determine the content of terminal groups in hyperbranched polymers based on the analysis of model hyperbranched aliphatic polyesters.

Abstract P6-04-13: Preclinical testing using a novel CT20p peptide-nanoparticle combination in breast cancer

Abstract BACKGROUND: The marked difference in metabolism observed between tumor and normal cells could contribute to the development of invasive and metastatic forms of breast cancer. The problem is that while patients diagnosed with invasive forms of breast cancer may be initially responsive to treatment, a significant number develop relapsing and even metastatic disease. There is a critical unmet need to develop new therapeutic approaches for patients diagnosed with invasive forms of breast cancer that are effective given the unique metabolism of tumor cells. METHODS: We examined the cytotoxic properties of a novel peptide, CT20p, derived from the C-terminus of Bax. For delivery to cells, the amphipathic nature of CT20p allowed it to be encapsulated in polymeric nanoparticles (NPs). NPs were made using aliphatic hyperbranched polyester (HBPE) that incorporated surface carboxylic groups and interior hydrophobic cavities for encapsulation of CT20p. To examine the cytotoxic potential and targeting capacity of CT20p-HBPE-NPs, we treated MDA-MB-231 breast cancer cells and MCF-10A breast epithelial cells with the peptide-nanoparticle combination and measured changes in mitochondrial function, cell metabolism and induction of apoptotic and non-apoptotic cell death. The ability of CT20p-NP-HBPE to cause tumor regression was examined by subcutaneously implanting MDA-MB-231 cells in nude mice. RESULTS: Initial studies showed that CT20p caused the release of calcein from mitochondrial-like lipid vesicles, without disrupting vesicle integrity, and, when expressed as a fusion protein in cells, localized to mitochondria. While the peptide alone had little effect upon intact cells, likely not penetrating the plasma membrane, when encapsulated and delivered by nanoparticles, CT20p-HBPE-NPs proved an effective killer of breast cancer cells. CT20p-HBPE-NPs initiated non-apoptotic cell death within 3 hours of treatment by targeting mitochondria and deregulating cellular metabolism. Nanoparticles alone or nanoparticles encapsulating a control peptide had minimal effects. The cytotoxicity of CT20p-HPBE-NPs was most pronounced in breast cancer cells, sparing normal, epithelial cells. In implanted breast tumors, CT20p-HBPE-NPs accumulated in tumors within 24 hours and reduced tumor burden by 50-80%. CONCLUSION: These results reveal the innovative features of CT20p that allow nanoparticle-mediated delivery to tumors and the potential application in combination therapies that target the unique metabolism of cancer cells. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-04-13.

H40-PCL-PEG unimolecular micelles both as anchoring sites for palladium nanoparticles and micellar catalyst for Heck reaction in water

A unimolecular micelle was employed both as anchoring sites for palladium nanoparticles and micellar catalyst for Heck reaction in water. In this system, the catalyst and substrates are concentrated in nanosize sites and therefore an efficient catalytic reaction occurs. The hyperbranched aliphatic polyester H40 has been functionalized with poly(caprolactone) (PCL) as hydrophobic core and polyethylene glycol (PEG) chains to obtain a water-soluble H40-PCL-PEG polymer which exhibits unimolecular micellar properties. The H40-PCL-PEG was effectively employed as a substrate for in-situ generation of Pd nanoparticles and also as a micellar catalyst. 1H·NMR, FT-IR, atomic absorption spectrometry (AAS), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to characterize the synthesized catalyst. The application of palladium nanoparticles immobilized on H40-PCL-PEG (PdNPs@H40-PCL-PEG UMs) as an efficient nanocatalyst toward Heck reaction in different conditions was investigated. The catalyst were found to be very active in Heck reactions of aryl iodides, bromides and also chlorides with olefinic compounds in water at room temperature with short reaction time duration and high yields. The catalyst can be recycled several times by extraction, dialysis or ultracentrifuge methods without loss in activity.