Intrafibrillar silicified collagen scaffold modulates monocyte to promote cell homing, angiogenesis and bone regeneration.
The immunomodulatory functions of monocytes are increasingly being recognized. Silicified collagen scaffolds (SCSs), produced by infiltrating collagen matrices with intrafibrillar amorphous silica, exhibit osteogenic and angiogenic potential and are promising candidates in tissue engineering. Here, we demonstrate that SCS promotes in situ bone regeneration and angiogenesis via monocyte immunomodulation. Increased numbers of TRAP-positive monocytes, nestin-positive bone marrow stromal cells (BMSCs) and CD31-positive and endomucin-positive new vessels can be identified from new bone formation regions in a murine calvarial defect model. In addition, sustained release of silicic acid by SCS stimulates differentiation of blood-derived monocytes into TRAP-positive cells, with increased expressions of SDF-1α, TGF-β1, VEGFa and PDGF-BB. These cytokines further promote homing of BMSCs and endothelial progenitor cells as well as neovascularization. Taken together, these novel findings indicate that SCSs possess the ability to enhance recruitment of progenitor cells and promote osteogenesis and angiogenesis by immunomodulation of monocytes.
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
Jin-Long
JL
Sun
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
Kai
K
Jiao
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China. Electronic address: niulina831013@126.com.
Li-Na
LN
Niu
Department of Stomatology, PLA Army General Hospital, Beijing, PR China.
Yang
Y
Jiao
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
Qun
Q
Song
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
Li-Juan
LJ
Shen
The Dental College of Georgia, Augusta University, Augusta, GA, USA. Electronic address: ftay@augusta.edu.
Franklin R
FR
Tay
State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China. Electronic address: jhchen@fmmu.edu.cn.
Ji-Hua
JH
Chen
D000818:Animals; D001861:Bone Regeneration; D002478:Cells, Cultured; D002633:Chemotaxis; D003094:Collagen / Q000737:chemistry* / Q000276:immunology; D056747:Immunomodulation; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000276:immunology; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000166:cytology* / Q000276:immunology; D018919:Neovascularization, Physiologic; D012824:Silicic Acid / Q000737:chemistry* / Q000276:immunology; D012886:Skull / Q000098:blood supply / Q000276:immunology / Q000293:injuries / Q000502:physiology*; D054457:Tissue Scaffolds / Q000737:chemistry*
D012824:Silicic Acid; D003094:Collagen
Angiogenesis; Bone regeneration; Cell homing; Immunomodulation; Intrafibrillar silicification; Monocytes