title: Novel in vivo-degradable cellulose-chitin copolymer from metabolically engineered Gluconacetobacter xylinus.
abstract: Despite excellent biocompatibility and mechanical properties, the poor in vitro and in vivo degradability of cellulose has limited its biomedical and biomass conversion applications. To address this issue, we report a metabolic engineering-based approach to the rational redesign of cellular metabolites to introduce N-acetylglucosamine (GlcNAc) residues into cellulosic biopolymers during de novo synthesis from Gluconacetobacter xylinus. The cellulose produced from these engineered cells (modified bacterial cellulose [MBC]) was evaluated and compared with cellulose produced from normal cells (bacterial cellulose [BC]). High GlcNAc content and lower crystallinity in MBC compared to BC make this a multifunctional bioengineered polymer susceptible to lysozyme, an enzyme widespread in the human body, and to rapid hydrolysis by cellulase, an enzyme commonly used in biomass conversion. Degradability in vivo was demonstrated in subcutaneous implants in mice, where modified cellulose was completely degraded within 20 days. We provide a new route toward the production of a family of tailorable modified cellulosic biopolymers that overcome the longstanding limitation associated with the poor degradability of cellulose for a wide range of potential applications.
authors.affiliation: Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Yadav
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Paniliatis
authors.forename: Hai
authors.initials: H
authors.lastname: Shi
authors.forename: Kyongbum
authors.initials: K
authors.lastname: Lee
authors.forename: Peggy
authors.initials: P
authors.lastname: Cebe
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D057005:Bioengineering / Q000379:methods*; D001704:Biopolymers / Q000096:biosynthesis* / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism* / Q000648:ultrastructure; D002686:Chitin / Q000378:metabolism*; D002853:Chromatography, Liquid; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018274:Electroporation; D041822:Gluconacetobacter xylinus / Q000378:metabolism*; D051379:Mice; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009113:Muramidase / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017550:Spectroscopy, Fourier Transform Infrared; D053719:Tandem Mass Spectrometry; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D017931:DNA Primers; D002686:Chitin; D002482:Cellulose; D009113:Muramidase