title: Fast and safe fabrication of a free-standing chitosan/alginate nanomembrane to promote stem cell delivery and wound healing.
abstract: Polymeric ultrathin membranes that are compatible with cells offer tremendous advantages for tissue engineering. In this article, we report a free-standing nanomembrane that was developed using a layer-by-layer self-assembly technique with a safe and sacrificial substrate method. After ionization, two oppositely charged polyelectrolytes, alginate and chitosan, were alternately deposited on a substrate of a solidified gelatin block to form an ultrathin nanomembrane. The space between the two adjacent layers was ∼200 nm. The thickness of the nanomembrane was proportional to the number of layers. The temperature-sensitive gelatin gel served as a sacrificial template at 37°C. The free-standing nanomembrane promoted bone marrow stem cell adhesion and proliferation. Fluorescence-activated cell sorting was used to analyze green-fluorescent-protein-positive mesenchymal stem cells from the wounds, which showed a significantly high survival and proliferation from the nanomembrane when cells were transplanted to mouse dorsal skin that had a full-thickness burn. The bone-marrow-stem-cell-loaded nanomembrane also accelerated wound contraction and epidermalization. Therefore, this methodology provides a fast and facile approach to construct free-standing ultrathin scaffolds for tissue engineering. The biocompatibility and free-standing nature of the fabricated nanomembrane may be particularly useful for stem cell delivery and wound healing.
authors.affiliation: Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing Key Laboratory for Diseases Proteomics, Third Military Medical University, Chongqing, People's Republic of China; Department of Mechanical Engineering, Biochemistry and Medical Genetics, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Yi
authors.initials: Y
authors.lastname: Kong
authors.affiliation: Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing Key Laboratory for Diseases Proteomics, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Mechanical Engineering, Biochemistry and Medical Genetics, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Darabi
authors.affiliation: Department of Biosystem Engineering, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhong
authors.affiliation: Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing Key Laboratory for Diseases Proteomics, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Gaoxing
authors.initials: G
authors.lastname: Luo
authors.affiliation: Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing Key Laboratory for Diseases Proteomics, Third Military Medical University, Chongqing, People's Republic of China; Department of Mechanical Engineering, Biochemistry and Medical Genetics, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Malcolm Mq
authors.initials: MM
authors.lastname: Xing
authors.affiliation: Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing Key Laboratory for Diseases Proteomics, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D002056:Burns / Q000628:therapy; D048271:Chitosan / Q000737:chemistry*; D005260:Female; D005434:Flow Cytometry; D005780:Gelatin; D020723:Glucuronic Acid / Q000737:chemistry; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006603:Hexuronic Acids / Q000737:chemistry; D008567:Membranes, Artificial; D059630:Mesenchymal Stem Cells; D008810:Mice, Inbred C57BL; D049329:Nanostructures / Q000008:administration & dosage / Q000737:chemistry*; D033581:Stem Cell Transplantation / Q000379:methods; D013234:Stem Cells / Q000166:cytology; D023822:Tissue Engineering / Q000379:methods; D014945:Wound Healing / Q000502:physiology
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D049452:Green Fluorescent Proteins; D020723:Glucuronic Acid; D005780:Gelatin; D048271:Chitosan
keywords: cell delivery; layer-by-layer; nanomembrane; wound healing