Bone is a highly dynamic and vascularized tissue that provides vital structural
support to the body. Bone defects, caused by disease or trauma, are a substantial
health problem nowadays. The limited efficacy of conventional treatment
strategies for bone regeneration has inspired the development of scaffold-based
tissue engineering. In this study, we aimed to analyze the biocompatibility of
human adipose stem cells (hASCs)-contained silk fibroin (SF) (SF-hASCs)
scaffold for bone tissue engineering through in vitro and in vivo study. The SF
scaffold was prepared through lyophilization method. To assess the suitability of
SF scaffold as an implant for bone regeneration, microstructure and
morphological characteristic of SF scaffold was examined by Fourier Transform
Infrared Microscope (FTIR) and Scanning Electron Microscope (SEM). The
results confirmed that the crystal structure of SF was not influenced during
lyophilization process and the morphological of scaffold presented a good
interconnectivity among the pores and an appropriate condition for the
development of cells inside the scaffold. The in vitro study results assessed by
MTT Assay and osteogenic differentiation by expression of extracellular matrix
(ECM) mineralization proved that SF scaffold was non-toxic and provide suitable
environment for hASCs to proliferated and differentiated into osteoblast. The in
vivo study which was examined by rat calvarial defect model showed the greatest
bone formation by SF-hASCs scaffold treatment, exhibited that this scaffold
biocompatible for in vivo implantation. In line with histological results, calvarial
defect treated with SF-hASCs scaffold exhibited the functionality of bone
regeneration showed by more collagen and blood vessels formation. Summarily,
our in vitro and in vivo study demonstrated that SF-hASCs scaffold can find
potential applications in bone repair and regeneration.

Bone is a highly dynamic and vascularized tissue that provides vital structural
support to the body. Bone defects, caused by disease or trauma, are a substantial
health problem nowadays. The limited efficacy of conventional treatment
strategies for bone regeneration has inspired the development of scaffold-based
tissue engineering. In this study, we aimed to analyze the biocompatibility of
human adipose stem cells (hASCs)-contained silk fibroin (SF) (SF-hASCs)
scaffold for bone tissue engineering through in vitro and in vivo study. The SF
scaffold was prepared through lyophilization method. To assess the suitability of
SF scaffold as an implant for bone regeneration, microstructure and
morphological characteristic of SF scaffold was examined by Fourier Transform
Infrared Microscope (FTIR) and Scanning Electron Microscope (SEM). The
results confirmed that the crystal structure of SF was not influenced during
lyophilization process and the morphological of scaffold presented a good
interconnectivity among the pores and an appropriate condition for the
development of cells inside the scaffold. The in vitro study results assessed by
MTT Assay and osteogenic differentiation by expression of extracellular matrix
(ECM) mineralization proved that SF scaffold was non-toxic and provide suitable
environment for hASCs to proliferated and differentiated into osteoblast. The in
vivo study which was examined by rat calvarial defect model showed the greatest
bone formation by SF-hASCs scaffold treatment, exhibited that this scaffold
biocompatible for in vivo implantation. In line with histological results, calvarial
defect treated with SF-hASCs scaffold exhibited the functionality of bone
regeneration showed by more collagen and blood vessels formation. Summarily,
our in vitro and in vivo study demonstrated that SF-hASCs scaffold can find
potential applications in bone repair and regeneration.

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