Surface Chemistry of Nanoscale Mineralized Collagen Regulates Periodontal Ligament Stem Cell Fate.
The interplay between stem cells and their extracellular microenvironment is of critical importance to the stem cell-based therapeutics in regenerative medicine. Mineralized collagen is the main component of bone extracellular matrix, but the effect of interfacial properties of mineralized collagen on subsequent cellular behaviors is unclear. This study examined the role of surface chemistry of nanoscale mineralized collagen on human periodontal ligament stem cell (hPDLSC) fate decisions. The intrafibrillarly mineralized collagen (IMC), fabricated by a biomimetic bottom-up approach, showed a bonelike hierarchy with nanohydroxyapatites (HAs) periodically embedded within fibrils. The infrared spectrum of the IMC showed the presence of phosphate, carbonate, amide I and II bands; and infrared mapping displayed uniform and higher spatial distribution of mineralization in the IMC. However, the distribution of the phosphate group differed far from that of the amide I group in the extrafibrillarly mineralized collagen (EMC), in which flowerlike HA clusters randomly depositing around the surface of the fibrils. Moreover, a large quantity of extrafibrillar HAs covered up the C═O stretch and N-H in-plane bend, resulting in substantial reduction of amide I and II bands. Cell experiments demonstrated that the hPDLSCs seeded on the IMC exhibited a highly branched, osteoblast-like polygonal shape with extended pseudopodia and thick stress fiber formation; while cells on the EMC displayed a spindle shape with less branch points and thin actin fibril formation. Furthermore, the biocompatibility of EMC was much lower than that of IMC. Interestingly, even without osteogenic induction, mRNA levels of major osteogenic differentiation genes were highly expressed in the IMC during cultivation time. These data suggest that the IMC with a similar nanotopography and surface chemistry to natural mineralized collagen directs hPDLSCs toward osteoblast differentiation, providing a promising scaffold in bone tissue regeneration.
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Yu
Y
Fu
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Shuai
S
Liu
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Sheng-Jie
SJ
Cui
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Xiao-Xing
XX
Kou
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Xue-Dong
XD
Wang
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Xiao-Mo
XM
Liu
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Yue
Y
Sun
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Gao-Nan
GN
Wang
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Yan
Y
Liu
Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology , Beijing 100081, P. R. China.
Yan-Heng
YH
Zhou
D002454:Cell Differentiation / Q000187:drug effects*; D003094:Collagen / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D010012:Osteogenesis; D010513:Periodontal Ligament / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects
D003094:Collagen
cell fate; interfacial microenvironment; intrafibrillar mineralization; surface chemistry; tissue regeneration