• 1 Indian Institute of Technology , Rubber Technology Centre, Kharagpur 721302, India
  • 2 Sanjay Gandhi Post Graduate Institute of Medical Science , Department of Medical Genetics, Lucknow 226014, Uttar Pradesh India
  • 3 Indian Institute of Technology , School of Medical Science and Technology, Kharagpur 721302, India
  • 4 Bharathidasan University , Department of Biotechnology and Genetic Engineering, Tiruchirappalli 620024, Tamilnadu India
  • 5 Indian Institute of Technology , RISUG® and Allied Science Laboratories, School of Medical Science and Technology, Kharagpur 721302, India
  • 6 Universiti Teknologi Malaysia , Faculty of Bioscience and Medical Engineering, IJN-UTM Cardiovascular Engineering Centre, Johor Bahru 81310, Malaysia
  • 7 National Institute of Technology Karnataka , Department of Metallurgical and Materials Engineering, Mangalore 575025, Karnataka India
ACS Appl Mater Interfaces, 2016 Feb 17;8(6):4086-100.
PMID: 26799576 DOI: 10.1021/acsami.5b11723


Guided bone regeneration (GBR) scaffolds are futile in many clinical applications due to infection problems. In this work, we fabricated GBR with an anti-infective scaffold by ornamenting 2D single crystalline bismuth-doped nanohydroxyapatite (Bi-nHA) rods onto segmented polyurethane (SPU). Bi-nHA with high aspect ratio was prepared without any templates. Subsequently, it was introduced into an unprecedented synthesized SPU matrix based on dual soft segments (PCL-b-PDMS) of poly(ε-caprolactone) (PCL) and poly(dimethylsiloxane) (PDMS), by an in situ technique followed by electrospinning to fabricate scaffolds. For comparison, undoped pristine nHA rods were also ornamented into it. The enzymatic ring-opening polymerization technique was adapted to synthesize soft segments of PCL-b-PDMS copolymers of SPU. Structure elucidation of the synthesized polymers is done by nuclear magnetic resonance spectroscopy. Sparingly, Bi-nHA ornamented scaffolds exhibit tremendous improvement (155%) in the mechanical properties with excellent antimicrobial activity against various human pathogens. After confirmation of high osteoconductivity, improved biodegradation, and excellent biocompatibility against osteoblast cells (in vitro), the scaffolds were implanted in rabbits by subcutaneous and intraosseous (tibial) sites. Various histological sections reveal the signatures of early cartilage formation, endochondral ossification, and rapid bone healing at 4 weeks of the critical defects filled with ornamented scaffold compared to SPU scaffold. This implies osteogenic potential and ability to provide an adequate biomimetic microenvironment for mineralization for GBR of the scaffolds. Organ toxicity studies further confirm that no tissue architecture abnormalities were observed in hepatic, cardiac, and renal tissue sections. This finding manifests the feasibility of fabricating a mechanically adequate nanofibrous SPU scaffold by a biomimetic strategy and the advantages of Bi-nHA ornamentation in promoting osteoblast phenotype progression with microbial protection (on-demand) for GBR applications.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.