title: Preconditioning of mesenchymal stromal cells toward nucleus pulposus-like cells by microcryogels-based 3D cell culture and syringe-based pressure loading system.
abstract: To precondition mesenchymal stromal/stem cells (MSCs) with mechanical stimulation may enhance cell survival and functions following implantation in load bearing environment such as nucleus pulposus (NP) in intervertebral disc (IVD). In this study, preconditioning of MSCs toward NP-like cells was achieved in previously developed poly (ethylene glycol) diacrylate (PEGDA) microcryogels (PMs) within a syringe-based three-dimensional (3D) culture system which provided a facile and cost-effective pressure loading approach. PMs loaded with alginate and MSCs could be incubated in a sealable syringe which could be air-compressed to apply pressure loading through a programmable syringe pump. Expression levels of chondrogenic marker genes SOX9, COL II, and ACAN were significantly upregulated in MSCs when pressure loading of 0.2 MPa or 0.8 MPa was implemented. Expression levels of COL I and COL X were downregulated when pressure loading was applied. In a nude mouse model, MSCs loaded in PMs mechanically stimulated for three days were subcutaneously injected using the same culture syringe. Three weeks postinjection, more proteoglycans (PGs) were deposited and more SOX9 and COL II but less COL I and COL X were stained in 0.2 MPa group. Furthermore, injectable MSCs-loaded PMs were utilized in an ex vivo rabbit IVD organ culture model that demonstrated the leak-proof function and enhanced cell retention of PMs assisted cell delivery to a load bearing environment for potential NP regeneration. This microcryogels-based 3D cell culture and syringe-based pressure loading system represents a novel method for 3D cell culture with mechanical stimulation for better function. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 507-520, 2017.
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
authors.forename: Siyu
authors.initials: S
authors.lastname: Feng
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
authors.forename: Qinyouen
authors.initials: Q
authors.lastname: Fu
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China.
authors.forename: Yaqian
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China.
authors.forename: Xiaokang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Navy General Hospital, Beijing, 100048, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Plastic and Reconstructive Surgery, Beijing Tsinghua Changgung Hospital; Medical Center, Tsinghua University, Beijing, 102218, China.
authors.forename: Chenyu
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China.
authors.forename: Zigang
authors.initials: Z
authors.lastname: Ge
authors.affiliation: Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Du
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000187:drug effects*; D059985:Cryogels / Q000737:chemistry / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007403:Intervertebral Disc / Q000166:cytology / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology; D011817:Rabbits
chemical_list: D000943:Antigens, Differentiation; D059985:Cryogels; C437167:poly(ethylene glycol)diacrylate; D011092:Polyethylene Glycols
keywords: MSCs; NP-like cells; microcryogels; organ culture; pressure loading