title: Effects of poly(lactic-co-glycolic acid) (PLGA) degradability on the apatite-forming capacity of electrospun PLGA/SiO(2)-CaO nonwoven composite fabrics.
abstract: We investigated the effects of poly(lactic-co-glycolic acid) (PLGA) degradability on the apatite-forming ability of electrospun PLGA/SiO(2)-CaO gel composite fabric. Two PLGA copolymer compositions with low and high degradability were used in experiments. A nonwoven polymer/ceramic composite fabric composed of randomly mixed microsized biodegradable PLGA fibers and nanosized bioactive SiO(2)-CaO gel fibers was prepared using a simultaneous electrospinning method. A 17 wt.% PLGA solution was prepared using 1,1,3,3-hexafluoro-2-propanol as a solvent, while the SiO(2)-CaO gel solution was prepared via a condensation reaction following hydrolysis of tetraethyl orthosilicate under acidic conditions. PLGA and SiO(2)-CaO gel solutions were spun simultaneously with two separate nozzles under electric fields of 1 and 2 kV/cm using two syringe pumps with flow rates of 7.5 and 5 mL/h, respectively. As controls, low and high degradable PLGA and SiO(2)-CaO gel nonwoven fabrics were also made by the same methods. The five nonwoven fabrics that were produced were exposed to simulated body fluid (SBF) for 1 week. SBF exposure resulted in the deposition of a layer of apatite crystals on the surfaces of both the SiO(2)-CaO gel and the low degradable PLGA/SiO(2)-CaO gel composite fabrics, but not on the low and high degradable PLGA or the high degradable PLGA/SiO(2)-CaO gel composite fabrics. The results are explained in terms of the acidity of the PLGA degradation products, which could have a direct influence on apatite dissolution.
authors.affiliation: Department of Dental Biomaterials Science, Dental Research Institute and BK21 HLS, School of Dentistry, Graduate School, Seoul National University, Seoul 110-749, Korea.
authors.forename: In Ae
authors.initials: IA
authors.lastname: Kim
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Rhee
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids; D017610:Calcium Compounds; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010087:Oxides; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012822:Silicon Dioxide; D017550:Spectroscopy, Fourier Transform Infrared; D013784:Textiles; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D010087:Oxides; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012822:Silicon Dioxide; C016538:lime