title: 31P and 13C solid-state NMR spectroscopy to study collagen synthesis and biomineralization in polymer-based bone implants.
abstract: A combination of solid-state NMR spectroscopy and MRI was used to evaluate the formation of extracellular matrix in poly(D,L-lactide-co-glycolide) (PLGA) bone implants. Porous PLGA scaffolds were implanted into rat tibiae and analysed after 2, 4 or 8 weeks. MRI clearly delineated the implants within the cancellous bone. Differences in the trabecular structure of the implanted material and native bone were demonstrated. In addition, implants were analyzed by solid-state NMR spectroscopy under magic angle spinning. (13)C NMR spectra showed the unambiguous signature of collagen formed in the scaffolds, but also the characteristic signals of the PLGA matrix, indicating that resorption was not complete after 8 weeks. Furthermore, (31)P NMR spectroscopy detected the inorganic component of the matrix, which is composed of bioapatite. (31)P NMR spectra were quantified and this analysis revealed that the amount of inorganic extracellular matrix formed de novo was significantly lower than in native bone. This demonstrates that solid-state NMR spectroscopy, in particular in combination with MRI, can provide useful information on the composition and structure of the extracellular matrix, and serve as a tool to evaluate the quality of tissue engineering strategies.
authors.affiliation: Institute of Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Weber
authors.forename: Julia
authors.initials: J
authors.lastname: Böhme
authors.forename: Holger A
authors.initials: HA
authors.lastname: Scheidt
authors.forename: Wilfried
authors.initials: W
authors.lastname: Gründer
authors.forename: Stefan
authors.initials: S
authors.lastname: Rammelt
authors.forename: Michael
authors.initials: M
authors.lastname: Hacker
authors.forename: Michaela
authors.initials: M
authors.lastname: Schulz-Siegmund
authors.forename: Daniel
authors.initials: D
authors.lastname: Huster
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology / Q000502:physiology*; D002113:Calcification, Physiologic; D003094:Collagen / Q000096:biosynthesis*; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D005260:Female; D020007:Implants, Experimental; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011100:Polyglycolic Acid / Q000737:chemistry / Q000378:metabolism; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen