title: Sugar-mediated chitosan/poly(ethylene glycol)-beta-dicalcium pyrophosphate composite: mechanical and microstructural properties.
abstract: The microstructural and mechanical properties of sugar-mediated chitosan/poly(ethylene glycol)-based scaffolds and composites, which are composed of beta-dicalcium pyrophosphate (beta-DCP) and sugar-mediated scaffolds, were investigated. All of the scaffolds were prepared by various freeze-drying protocols. The differences in the freeze-drying process of the sugar-mediated chitosan/poly(ethylene glycol) scaffold for three types of sugar (sucrose, glucose, and D-fructose) were determined by scanning electron microscopic observation, water retention, density, and porosity analyses. The sugar-mediated scaffolds prepared by scheme I of the freeze-drying process show large pores, poorly connective interlayers, and disintegrated inner structures, different from the small pores and well-connective channel structures as shown in the scheme II freeze-drying process. The key factors for controlling pore structure and size in the scheme I freeze-drying process were formulation and composition, but for the scheme II freeze-drying process, the key factor was freeze protocol. The composite scaffolds were macroporous, and the microstructure changed considerably with added beta-DCP content. The incorporation of beta-DCP granules caused a significant enhancement of compressive modulus and yield strength. The increased mechanical strength may be attributable not only to the physical complexation between the sugar-mediated scaffold and beta-DCP, but also the chemical reaction to apatite formed on the cell wall.
authors.affiliation: Department of Materials Science and Engineering, National Cheng-Kung University, Tainan 70101, Taiwan, Republic of China. jinwen.tw@yahoo.com.tw
authors.forename: Jian-Wen
authors.initials: JW
authors.lastname: Wang
authors.forename: Min-Hsiung
authors.initials: MH
authors.lastname: Hon
mesh_terms: D001673:Biodegradation, Environmental; D001696:Biomechanical Phenomena; D002131:Calcium Pyrophosphate / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D002516:Ceramics; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry*; D048271:Chitosan; D003188:Composite Resins; D003432:Cross-Linking Reagents; D005612:Freeze Drying; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry*; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D002241:Carbohydrates; D003188:Composite Resins; D003432:Cross-Linking Reagents; D014867:Water; D002686:Chitin; D011092:Polyethylene Glycols; D048271:Chitosan; D002131:Calcium Pyrophosphate