title: A biofriendly silica gel for in situ protein entrapment: biopolymer-assisted formation and its kinetic mechanism.
abstract: In an attempt to develop a biofriendly sol-gel route for the rapid formation of biofunctional silica gels, a biopolymer with good biocompatibility was used to assist the gelation of glycol-modified tetraethoxysilane (GMT) in aqueous system without the addition of any organic solvents. It was found that the biopolymer used could act as an effective accelerator for the sol-gel transition of GMT and an increase of its amount could shorten greatly the gelation time. For such a gelation reaction, its apparent activation energy was determined to be 64.9 kJ/mol according to the Arrhenius equation. In particular, the kinetic mechanism for the formation of the silica gel was investigated by using dynamic theological data and a scaling fractal model. It was revealed that the biopolymer used could change the sol-gel transition mechanism from reaction-limited kinetics to diffusion-limited kinetics. Circular dichroism analyses confirmed the suitability of using the resultant silica gel for the in situ protein encapsulation.
authors.affiliation: Laboratory for Polymer Composite and Functional Materials, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275, China.
authors.forename: Guan-Hai
authors.initials: GH
authors.lastname: Wang
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D002417:Cattle; D048271:Chitosan / Q000737:chemistry; D002942:Circular Dichroism; D004058:Diffusion; D017709:Fractals; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D011506:Proteins / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D012709:Serum Albumin / Q000737:chemistry; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D001704:Biopolymers; D011506:Proteins; D012709:Serum Albumin; D012997:Solvents; D058428:Silica Gel; D012822:Silicon Dioxide; D048271:Chitosan