Physico-chemical and biological studies on three-dimensional porous silk/spray-dried mesoporous bioactive glass scaffolds

Abstract

a b s t r a c tThe incorporation of a bioactive inorganic phase in polymeric scaffolds is a good strategy for the improvement of the bioactivity and the mechanical properties, which represent crucial features in the field of bone tissue engineering. In this study, spray-dried mesoporous bioactive glass particles (SD-MBG), belonging to the binary system of SiO 2 -CaO (80:20 mol%), were used to prepare composite scaffolds by freeze-drying technique, using a silk fibroin matrix. The physico-chemical and biological properties of the scaffolds were extensively studied. The scaffolds showed a highly interconnected porosity with a mean pore size in the range of 150 mm for both pure silk and silk/SD-MBG scaffolds. The elastic moduli of the silk and silk/SD-MBG scaffolds were 1.1 7 0.2 MPa and 6.9 7 1.0 MPa and compressive strength were 0.5 70.05 MPa and 0.9 70.2 MPa, respectively, showing a noticeable increase of the mechanical properties of the composite scaffolds compared to the silk ones. The contact angle value decreased from 105.3°to 71.2°with the incorporation of SD-MBG particles. Moreover, the SD-MBG incorporation countered the lack of bioactivity of the silk scaffolds inducing the precipitation of hydroxyapatite layer on their surface already after 1 day of incubation in simulated body fluid. The composite scaffolds showed good biocompatibility and a good alkaline phosphatase activity toward human mesenchymal stromal cells, showing the ability for their use as three-dimensional constructs for bone tissue engineering.

Bioactive glass-based materials with hierarchical porosity for medical applications: Review of recent advances

“…The obtained composite scaffolds showed increased mechanical strength up to 1 MPa compared to the pure silk reference material, formation of surface hydroxyapatite after 24 h and a high ALP activity [106]. Su et al used solvent casting and particulate leaching to fabricate MBG/polyamide scaffolds that exhibited excellent biocompatibility and osteoconductivity as well as more effective osteogenesis than the reference polyamide scaffold in vivo [107].…”

Composite Biomaterials Based on Sol-Gel Mesoporous Silicate Glasses: A Review

“…Silk fibroin and spray-dried MBG particles were also used to fabricate porous composites by freeze-drying: compared to the pure silk constructs, the hierarchical macro-mesoporous scaffolds exhibited an improved mechanical strength (up to 1 MPa) and a fast apatite-forming ability in vitro (hydroxyapatite agglomerates visible after 1 day in SBF) [ 26 ]. Similar results were obtained incorporating MBG particles obtained by a “conventional” wet synthesis into macroporous silk scaffolds [ 27 ].…”

Preparation and characterization of spray‐dried granulated bioactive glass micron spheres

“…Although studies have demonstrated the preparation of micron‐sized BG powders via the spray drying method, the resulting particle sizes have been approximately 5 to 10 μm 24,25 . The size remains too small, while concave surfaces are found among larger particles.…”