title: Preparation of stable insulin-loaded nanospheres of poly(ethylene glycol) macromers and N-isopropyl acrylamide.
abstract: A series of nanospheres composed of temperature-sensitive poly(N-isopropylacrylamide), poly(ethylene glycol) 400 dimethacrylate, and poly(ethylene glycol) 1000 methacrylate was prepared by a thermally-initiated free radical dispersion polymerization method. Insulin was loaded into the nanoparticles by equilibrium partitioning. The loading capacity of insulin into the nanoparticles was 2.1% (2.1 mg insulin/100 mg nanoparticles). The stability of the loaded insulin at elevated temperatures was investigated by reverse phase high pressure liquid chromatography. The nanoparticles were able to protect the loaded insulin, as more than 80% of the loaded insulin could still be detected compared to 0% for the control (0.1% insulin solution in PBS) when heated to 80 degrees C for 5 h. The stability of the loaded insulin at high shear stress (289 1/s) was also investigated. No significant loss of insulin was detected both from nanoparticles loaded with insulin sample and the control (0.1% insulin solution in PBS). The results showed that shear stress alone did not have a major effect on insulin denaturation. The ability of the nanoparticles to protect the insulin from high temperature and high shear stress made the system a good candidate as a carrier for insulin for fluidized bed coating technology.
authors.affiliation: Biomaterials and Drug Delivery Laboratories, School of Chemical Engineering, Purdue University, W. Lafayette, IN 47907, USA.
authors.forename: William
authors.initials: W
authors.lastname: Leobandung
authors.forename: Hideki
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Fukumori
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Peppas
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D004339:Drug Compounding / Q000379:methods / Q000706:statistics & numerical data; D007004:Hypoglycemic Agents / Q000138:chemical synthesis / Q000737:chemistry; D007328:Insulin / Q000138:chemical synthesis / Q000737:chemistry*; D008863:Microspheres; D036103:Nanotechnology / Q000379:methods* / Q000706:statistics & numerical data; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D000178:Acrylamides; D007004:Hypoglycemic Agents; D007328:Insulin; D011092:Polyethylene Glycols; C067295:N-isopropylacrylamide