title: In vivo experimental study on bone regeneration in critical bone defects using PIB nanogels/boron-containing mesoporous bioactive glass composite scaffold.
abstract: OBJECTIVE
  In the present study, the fabrication of novel p(N-isopropylacrylamide-co-butyl methylacrylate) (PIB) nanogels was combined with boron-containing mesoporous bioactive glass (B-MBG) scaffolds in order to improve the mechanical properties of PIB nanogels alone. Scaffolds were tested for mechanical strength and the ability to promote new bone formation in vivo.
  
  
  METHODS
  To evaluate the potential of each scaffold in bone regeneration, ovariectomized rats were chosen as a study model to determine the ability of PIB nanogels to stimulate bone formation in a complicated anatomical bone defect. PIB nanogels and PIB nanogels/B-MBG composites were respectively implanted into ovariectomized rats with critical-sized femur defects following treatment periods of 2, 4, and 8 weeks post-implantation.
  
  
  RESULTS
  Results from the present study demonstrate that PIB nanogels/B-MBG composites showed greater improvement in mechanical strength when compared to PIB nanogels alone. In vivo, hematoxylin and eosin staining revealed significantly more newly formed bone in defects containing PIB nanogels/B-MBG composite scaffolds when compared to PIB nanogels alone. Tartrate-resistant acid phosphatase-positive staining demonstrated that both scaffolds were degraded over time and bone remodeling occurred in the surrounding bone defect as early as 4 weeks post-implantation.
  
  
  CONCLUSIONS
  The results from the present study indicate that PIB nanogels are a potential bone tissue engineering biomaterial able to treat defects of irregular shapes and deformities as an injectable, thermoresponsive, biocompatible hydrogel which undergoes rapid thermal gelation once body temperature is reached. Furthermore, its combination with B-MBG scaffolds improves the mechanical properties and ability to promote new bone formation when compared to PIB nanogels alone.
authors: State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, People's Republic of China ; Department of Dental Implantology, School and Hospital of Stomatology, Wuhan University, People's Republic of China.
authors: Xiaohui
authors: X
authors: Chen
authors: National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors: Yanbing
authors: Y
authors: Zhao
authors: National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors: Shinan
authors: S
authors: Geng
authors: State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, People's Republic of China.
authors: Richard J
authors: RJ
authors: Miron
authors: State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, People's Republic of China.
authors: Qiao
authors: Q
authors: Zhang
authors: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, People's Republic of China.
authors: Chengtie
authors: C
authors: Wu
authors: State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, People's Republic of China ; Department of Dental Implantology, School and Hospital of Stomatology, Wuhan University, People's Republic of China.
authors: Yufeng
authors: Y
authors: Zhang
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001861:Bone Regeneration / Q000502:physiology*; D001895:Boron / Q000737:chemistry*; D005260:Female; D005269:Femur / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D005898:Glass / Q000737:chemistry*; D007527:Isoenzymes / Q000378:metabolism; D000080385:Nanogels; D010012:Osteogenesis; D010052:Ovariectomy; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D016062:Porosity; D051381:Rats; D017208:Rats, Wistar; D000071681:Tartrate-Resistant Acid Phosphatase; D054457:Tissue Scaffolds
chemical_list: D000179:Acrylates; D001672:Biocompatible Materials; D007527:Isoenzymes; D000080385:Nanogels; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D001895:Boron
keywords: bone graft; boron; mesoporous bioactive graft; osteoporosis; osteoporotic defect; tissue engineering
references: J Dent Res. 2012 Aug;91(8):736-44
references: 22318372
references: Mol Ther. 2008 Jul;16(7):1243-51
references: 18500247
references: Bone. 2012 Oct;51(4):704-13
references: 22796416
references: AJNR Am J Neuroradiol. 2013 Jan;34(1):169-76
references: 22859278
references: J Mater Sci Mater Med. 2013 Aug;24(8):1963-75
references: 23674058
references: Clin Oral Investig. 2014;18(2):471-8
references: 23652357
references: Osteoporos Int. 2014 Aug;25(8):2089-96
references: 24807629
references: Clin Oral Implants Res. 2015 Apr;26(4):383-91
references: 24547966
references: Macromol Rapid Commun. 2012 Jan;33(2):120-6
references: 22139810
references: Clin Implant Dent Relat Res. 2015 Oct;17(5):996-1003
references: 24393521
references: J Biomed Mater Res B Appl Biomater. 2008 Nov;87(2):374-80
references: 18435403
references: J Cell Physiol. 2009 Jul;220(1):1-7
references: 19301257
references: Osteoporos Int. 2009 Oct;20(10):1633-50
references: 19421703
references: J Biosci Bioeng. 2009 Dec;108(6):530-7
references: 19914589
references: Biomaterials. 2010 May;31(13):3429-38
references: 20122721
references: Curr Rheumatol Rep. 2010 Jun;12(3):186-91
references: 20425518
references: Biomaterials. 2010 Dec;31(36):9452-61
references: 20869769
references: Annu Rev Med. 2011;62:307-22
references: 21054170
references: Bone. 2011 Feb;48(2):298-306
references: 20870047
references: Acta Biomater. 2011 Jun;7(6):2644-50
references: 21402182
references: Am J Nurs. 2011 Aug;111(8):26-35; quiz 36-7
references: 21795930
references: Biomaterials. 2011 Oct;32(29):7068-78
references: 21704367
references: Osteoporos Int. 1999;10(4):259-64
references: 10692972
references: J Biomed Mater Res. 2002 Jul;61(1):109-20
references: 12001253
references: Med J Aust. 2004 Mar 15;180(6):298-303
references: 15012571
references: J Biomed Mater Res. 1999 Mar 15;44(4):446-55
references: 10397949
references: Biomaterials. 2006 Jun;27(18):3413-31
references: 16504284
references: Biomaterials. 2006 Sep;27(25):4399-408
references: 16678255
references: Biomaterials. 2007 Apr;28(10):1830-7
references: 17208295
references: J Biomed Mater Res A. 2007 Mar 15;80(4):837-51
references: 17072851
references: J Control Release. 2007 May 14;119(1):5-24
references: 17382422
references: J Biomed Mater Res A. 2008 Jan;84(1):84-91
references: 17600329
references: Biomed Mater. 2006 Sep;1(3):100-5
references: 18458389
references: Biomaterials. 2012 Oct;33(28):6698-708
references: 22763224