Characterization of novel akermanite:poly-ϵ-caprolactone scaffolds for human adipose-derived stem cells bone tissue engineering

Abstract

In this study, three different akermanite:poly-ϵ-caprolactone (PCL) composite scaffolds (wt%: 75:25, 50:50, 25:75) were characterized in terms of structure, compression strength, degradation rate and in vitro biocompatibility to human adipose-derived stem cells (hASC). Pure ceramic scaffolds [CellCeram™, custom-made, 40:60 wt%; β-tricalcium phosphate (β-TCP):hydroxyapatite (HA); and akermanite] and PCL scaffolds served as experimental controls. Compared to ceramic scaffolds, the authors hypothesized that optimal akermanite:PCL composites would have improved compression strength and comparable biocompatibility to hASC. Electron microscopy analysis revealed that PCL-containing scaffolds had the highest porosity but CellCeram™ had the greatest pore size. In general, compression strength in PCL-containing scaffolds was greater than in ceramic scaffolds. PCL-containing scaffolds were also more stable in culture than ceramic scaffolds. Nonetheless, mass losses after 21 days were observed in all scaffold types. Reduced hASC metabolic activity and increased cell detachment were observed after acute exposure to akermanite:PCL extracts (wt%: 75:25, 50:50). Among the PCL-containing scaffolds, hASC cultured for 21 days on akermanite:PCL (wt%: 75:25) discs displayed the highest viability, increased expression of osteogenic markers (alkaline phosphatase and osteocalcin) and lowest IL-6 expression. Together, the results indicate that akermanite:PCL composites may have appropriate mechanical and biocompatibility properties for use as bone tissue scaffolds.

Photoactivated miR-148b–nanoparticle conjugates improve closure of critical size mouse calvarial defects

“…PCL was chosen as a scaffold for this study as it has previously been shown to have little impact on hASC differentiation, providing a convenient method to isolate the osteogenic activity of the PC-miR-148b–SNP photoactivated conjugate without osteogenic substrate effects [24]. The defect partially healed with the photoactivated conjugates while the control groups had minimal healing and remained opened even after 12 weeks, further verifying the model and the size of the non-healing defect.…”

Doped Calcium Silicate Ceramics: A New Class of Candidates for Synthetic Bone Substitutes

“…Several common synthetic polymers have been used to form composites with DCSCs, including polycaprolactone (PCL), poly(glycolic acid) (PGA) and poly(lactic-co-glycolic acid) (PLGA). Porous PCL-akermanite scaffolds (~90% porosity, ~100 µm pore size) were fabricated by loading akermanite powder into the PCL matrix at different weight ratios [121]. The highest compressive strength was attained at 25 wt % loading of akermanite particles (~10 MPa), compared to the other groups (50 wt % loaded, 75 wt % loaded, and PCL control) which all exhibited similar strengths (~4.3 MPa).…”

The Use of Adipose Tissue-Derived Progenitors in Bone Tissue Engineering - a Review

“…This was indicated by high alkaline phosphatase (ALP) activity, osteocalcin expression, and mineralization [31]. Using akermanite-based scaffolds, Zanetti and colleagues [32] have shown that ADSCs cultured for 21 days in osteogenic medium before seeding them on the scaffold have greater calcium deposition and osteocalcin expression and low IL-6 expression, compared with cells seeded on polycaprolactone-β-tricalcium phosphate. In an interesting study by Fröhlich and colleagues [33], ADSCs seeded on decellularized native bone scaffolds which provided the necessary structural and mechanical environment for osteogenic differentiation showed increased construct cellularity and elevated amounts of bone matrix components (collagen, bone sialoprotein, and osteopontin).…”