Amine-terminated poly (ethylene glycol) (PEG) was prepared by two steps. Firstly, potassium naphthalene was added to a solution of methoxypolyethylene glycol 5,000 in benzene until the solution maintains green in half of an hour, then excess tosylchloride was introduced; secondly, the conversion of the tosylate into an amine was carried out by Gabriel synthesis. The block copolymer poly (ethylene glycol)-co-poly (gamma-benzyl L-glutamate ) could be obtained by ring-opening polymerization of gamma-benzyl-L-glutamate N-carboxy anhydride with amine-terminated PEG as macroinitiator. And the benzyl group could be removed by sodium hydroxide. The product structure was characterized by IR, 1HNMR, GPC. The cisplatin-loaded micelle was observed by transmission electron microscope (TEM). And the block copolymer is expected to be useful as functional materials including carrier systems in drug controlled delivery applications.
Drug Carriers ; Polyethylene Glycols ; chemical synthesis ; Polyglutamic Acid ; Polymers ; chemical synthesis ; chemistry ; Surface Properties

PEG (Mn = 1000)-segmented polyurethanes, with hard segment percentage of 40%, 50% and 55% and named PU-H40, PU-H50 and PU-H55 respectively, were synthesized by bulk polymerization. The structure of PU was characterized by FTIR, DSC, and GPC. Mechanical properties, water contact angles and water vapor transmit rate(WVTR) were also tested. FTIR and DSC showed that the degree of microphase separation increased with the hard content. Mechanical test showed the tensile strength of PU-H50 to be 25 MPa, the highest tensile strength of the PU series. By the use of PEG as soft segment, the surface hydrophilicity of the materials increased dramatically. Owing to its high degree of microphase separation and the mobility of soft segment, the water contact angle of PU-H55 attained to 33 degrees. The WVTRs of PU-H40, PU-H50 and PU-H55 were 789 g/m2/24h, 705 g/m2/24h and 623g/m2/24h respectively. These data suggest that the materials are suitable for fabricating such biomedical articles as surgical gloves, wound dressing and medical protective coating.
Biocompatible Materials ; chemical synthesis ; chemistry ; Humans ; Polyethylene Glycols ; chemistry ; Polyurethanes ; chemical synthesis ; chemistry ; Spectroscopy, Fourier Transform Infrared ; Surface Properties

To improve the physical property and bioactivity of methotrexate, this paper investigated the new formation of conjugate methotrexate-poly (ethylene glycol) and in vitro anti-tumor activity of the synthesized conjugate. The conjugate of methotrexate-poly (ethylene glycol), which was verified by the spectroscopy analysis of UV, IR and 13C NMR, was synthesized by chemical catalysis and micro-wave irritation. The determination for the conjugate of solubility in water and distribution coefficient in octanol-water system of the conjugate was done to examine its deliquescence property. The solubility in water and the distribution coefficient of the conjugate was greatly improved, which was increased by 128 folds and 5 folds, respectively. The in vitro anti-tumor activity of the conjugate was tested by mouse L(1210) leukaemia cells, and the synthesized conjugate showed the same anti-tumor activity as the original methotrexate. Compared to the reported literature, the modification of methotrexate by poly (ethylene glycol) is more rapid and convenient.
Animals ; Antineoplastic Agents ; chemical synthesis ; Leukemia L1210 ; drug therapy ; Methotrexate ; chemical synthesis ; chemistry ; pharmacology ; Mice ; Polyethylene Glycols ; chemical synthesis ; chemistry ; pharmacology ; Solubility

The blood compatibility of block copolymer membranes of poly(benzyl L-glutamate)/poly(ethylene glycol) and the effect of on the blood compatibility of copolymer were evaluated by the clotting time test, the platelet adhesion and deformation test, and the protein adsorption test. The results showed that in terms of blood compatibility, homopolymer was better than glass and silicone, copolymer was better than homopolymer, and the more the PEG in the copolymer, the better the blood compatibility.
Biocompatible Materials ; Drug Carriers ; Materials Testing ; Platelet Adhesiveness ; drug effects ; Polyethylene Glycols ; chemical synthesis ; chemistry ; Polyglutamic Acid ; analogs & derivatives ; chemical synthesis ; chemistry ; Polymers ; chemical synthesis ; chemistry

A series of poly (lacticacid-co-glycolicacid)-poly(ethylene glycol) (PLGA-PEG, PELGA) block copolymers and poly (ethylene glycol)-poly (lacticacid-co-glycolicacid)-poly (ethylene-glycol) (PELGE) was synthesized by ring-opening polymerization. PELGA nanoparticles and PELGE nanoparticles were prepared using the emulsion-solvent evaporation technique (O/W). To study the behavior and mechanism of the degradation of PELGA-NP and PELGA-NP, we determined the lactic acids by UV spectrophotometry. The method confirmed that degradation was much faster for polymers with a decrease in the LA content of the polymers or an increase in the PEG content of the polymers.
Biocompatible Materials ; chemistry ; Biodegradation, Environmental ; Drug Carriers ; Drug Delivery Systems ; Humans ; Lactic Acid ; chemical synthesis ; chemistry ; Microspheres ; Nanostructures ; Nanotechnology ; Polyesters ; chemical synthesis ; chemistry ; Polyethylene Glycols ; chemical synthesis ; chemistry ; Polyglactin 910 ; chemistry ; Polyglycolic Acid ; chemical synthesis ; chemistry ; Polymers ; chemical synthesis ; chemistry

Adopting the two-step method and changing the proportion between PEG (Polyethylene glycol) and PTMG (poly (tetrahydrofuran), we used the MDI (4,4'-diphenylmethane diisocyanate) and short chain extender BDO (1,4-butanediol) as hard segment, the PTMG and PEG as soft segment, and hence prepared a series of polyether-based thermoplastic polyurethanes. FTIR showed the structure character of these polyurethanes. The determination of mechanics property and water contact angles revealed their good mechanics properties and hydrophilicity. Blood compatibility was evaluated by hemolysis test and platelet adhesion test, which revealed their good hemocompatibility. So those polyurethanes may be of wide application in the future.
Animals ; Biocompatible Materials ; chemical synthesis ; chemistry ; Butylene Glycols ; chemistry ; Isocyanates ; chemistry ; Materials Testing ; Polyethylene Glycols ; chemistry ; Polymers ; chemistry ; Polyurethanes ; chemical synthesis ; chemistry ; Rabbits

In this paper, a series of low-molecular-weight PEG-PCL-PEG triblock copolymers were successfully synthesized by ring-opening polymerization method, and were characterized using 1H-NMR and FTIR. The aqueous solution displayed specific thermosensitive gel-sol transition when the concentration was above corresponding critical gel concentration (CGC). The gel-sol phase diagram was recorded using test tube-inverting method, which was depended on the hydrophilic/hydrophobic balance in macromolecular structure, as well as heating history. As a result, the gel-sol transition temperature range could be altered, which might be very useful for its application as injectable drug delivery system.
Biocompatible Materials ; chemical synthesis ; chemistry ; Drug Carriers ; chemistry ; Drug Delivery Systems ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Polyesters ; chemical synthesis ; chemistry ; Polyethylene Glycols ; chemical synthesis ; chemistry ; Spectroscopy, Fourier Transform Infrared ; Temperature

The purpose of this study was to develop a novel polymer cuff for the local delivery of alpha-lipoic acid (ALA) to inhibit neointimal formation in vivo. The polymer cuff was fabricated by incorporating the ALA into poly-(D,L-lactide-co-caprolactone) 40:60 (PLC), with or without methoxy polyethylene glycol (MethoxyPEG). The release kinetics of ALA and in vitro degradation by hydrolysis were analyzed by HPLC and field emission scanning electron microscopy (FE-SEM), respectively. In vivo evaluation of the effect of the ALA-containing polymer cuff was carried out using a rat femoral artery cuff injury model. At 24 h, 48% or 87% of the ALA was released from PCL cuffs with or without MethoxyPEG. FE-SEM results indicated that ALA was blended homogenously in the PLC with MethoxyPEG, whereas ALA was distributed on the surface of the PLC cuff without MethoxyPEG. The PLC cuff with MethoxyPEG showed prolonged and controlled release of ALA in PBS, in contrast to the PLC cuff without MethoxyPEG. Both ALA-containing polymer cuffs had a significant effect on the inhibition of neointimal formation in rat femoral artery. Novel ALA-containing polymer cuffs made of PLC were found to be biocompatible and effective in inhibiting neointimal formation in vivo. Polymer cuffs containing MethoxyPEG allowed the release of ALA for one additional week, and the rate of drug release from the PLC could be controlled by changing the composition of the polymer. These findings demonstrate that polymer cuffs may be an easy tool for the evaluation of anti-restenotic agents in animal models.
Animals ; Coronary Restenosis/*therapy ; Delayed-Action Preparations ; Male ; Materials Testing ; Polyesters/*administration & dosage/*chemical synthesis ; Polyethylene Glycols/chemical synthesis ; Rats ; Rats, Sprague-Dawley ; Surface Properties

Biodegradable polymeric nanoparticles acting as drug carrier have important potential applications such as site-specific drug delivery and controllable drug delivery. However, these carriers cannot generally be used because they are eliminated by the reticulo-endothelial system within seconds or minutes after intravenous injection. To overcome this limitation, more and more researchers introduce hydrophilic polyethylene glyeol(PEG) to modify polymeric nanoparticles for avoiding their uptake by reticulo-endothelial system. Introducing PEG not only changes polymer nanoparticles' biodegradation in vivo, but also influences drug's properties such as drug release, in vivo biodistribution, et. al. In this paper are reviewed the researches of PEG-modified copolymer nanoparticles, including their preparation and size distribution, stability, drug incorporation, drug release, in vivo biodistribution, in vitro cytotoxicty. A prospect for the researches and developments of the PEG-modified copolymer nanoparticles was also made.
Animals ; Drug Carriers ; pharmacokinetics ; Drug Compounding ; methods ; Drug Delivery Systems ; In Vitro Techniques ; Nanotechnology ; Polyethylene Glycols ; chemical synthesis ; chemistry ; Polymers ; chemical synthesis ; chemistry

Five kinds of pore-forming agents, including PEG-400, chitosan, the polymer of chitosan and glutin, CaCO3 and NazCO3, were used in this experiment to prepare fast responsive and pH sensitive Polyacrylic acid (PAAc) gel which could be used as the material of punctum plug. The mechanism and effects of pore-forming agents on PAAc gel were studied; besides, the experiment also assessed the effects of the three most effective pore-forming agents on gel's water retention and swelling rate. The results showed that the most suitable dose levels of PEG-400, the polymer and Na2CO3 were 1 ml, 0.8 ml and 1 ml respectively, and PEG-400 was most effective with the same dosage; the gel with PEG-400 as pore-forming agent could finish more than 95% of the swelling process in just 5 minutes, it is suitable for use as punctum plug material.
Acrylic Resins ; chemistry ; Carbonates ; chemistry ; Chitosan ; chemistry ; Hydrogels ; chemical synthesis ; chemistry ; Hydrogen-Ion Concentration ; Ophthalmic Solutions ; chemical synthesis ; chemistry ; Polyethylene Glycols ; chemistry ; Polymers ; Porosity