Mechanical properties of highly porous PDLLA/Bioglass® composite foams as scaffolds for bone tissue engineering

Abstract

This study developed highly porous degradable composites as potential scaffolds for bone tissue engineering. These scaffolds consisted of poly-D,L-lactic acid filled with 2 and 15 vol.% of 45S5 Bioglass® particles and were produced via thermally induced solid-liquid phase separation and subsequent solvent sublimation. The scaffolds had a bimodal and anisotropic pore structure, with tubular macro-pores of ~100 µm in diameter, and with interconnected micro-pores of ~10-50 µm in diameter. Quasi-static and thermal dynamic mechanical analysis carried out in compression along with thermogravimetric analysis was used to investigate the effect of Bioglass® on the properties of the foams. Quasi-static compression testing demonstrated mechanical anisotropy concomitant with the direction of the macro-pores. An analytical modelling approach was applied, which demonstrated that the presence of Bioglass® did not significantly alter the porous architecture of these foams and reflected the mechanical anisotropy which was congruent with the scanning electron microscopy investigation. This study found that the Ishai-Cohen and Gibson-Ashby models can be combined to predict the compressive modulus of the composite foams. The modulus and density of these complex foams are related by a power-law function with an exponent between 2 and 3.

Ultralight, Soft Polymer Sponges by Self‐Assembly of Short Electrospun Fibers in Colloidal Dispersions

“…3), D) compression test of sponges of different densities, and E) Ashby plot of sponge compressive strength versus density for different materials. 1) Boron nitride, [ 9 ] 2) carbon nanotube, [ 6 ] 3) carbon aerogel, [ 15 ] 4) cellulose fi ber, [ 16 ] 5) cross-linked polystyrene, [ 17 ] 6) polyolefi n (closed cell), [ 18 ] 7) polyethylene (closed cell), [ 19 ] 8) polyimide, [ 20 ] 9) polyethylene (50% strain), [ 19 ] 10) silk fi broin, [ 21 ] 11) melamine-formaldehyde (rigid), [ 22 ] 12) tannin-based (rigid), [ 23 ] 13) PDLLA/Bioglass composite, [ 24 ] 14) latex rubber, [ 19 ] 15) PAN-microspheres and fi bers, [ 25 ] 16) rigid polyurethane, [ 26 ] 17) PVC (cross-linked), [ 27 ] 18) epoxy-boroxine, [ 28 ] 19) bio-based macroporous polymers, [ 29 ] 20) silicon oxycarbide ceramic, [ 30 ] and [ 21 ] ) aluminum foams. [ 31 ] www.afm-journal.de www.MaterialsViews.com…”

Bone tissue engineering by using a combination of polymer/Bioglass composites with human adipose-derived stem cells

“…Composite scaffolds comprising of PDLLA with Bioglass ® particle additions are of current interest for bone tissue engineering (Blaker et al 2003;Blaker et al 2005;Maquet et al 2003;Maquet et al 2004;Roether et al 2002;Yang et al 2006). Adipose tissue is an abundant source of mesenchymal stem cells, which have shown promise in the field of regenerative medicine (Hicok et al 2004;Lalande et al 2011;Parker and Katz 2006).…”

“…As a result, Bioglass ® is said to be both osteoproductive and osteoconductive. Incorporation of Bioglass particles in to a biodegradable polymer scaffold can be advantageous as it will impart bioactivity to the polymer matrix whilst reducing the autocatalytic degradation of polymers such as polylactide (Blaker et al 2005;Stamboulis et al 2002).…”

Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

“…In 2003, Boccaccini and Maquet [42] reported for the first time on the successful fabrication of porous foam-like bioactive glass containing poly(lactide-co-glycolide) (PLGA) composites, which exhibited well-defined, oriented and interconnected porosity. Since then, many studies have been carried out to optimize and investigate bone TE composite scaffolds concerning material combinations, bioactive properties, degradation characteristics [161,164,165,168], in vitro [47,[161][162][163]169] and in vivo behavior [47,164], as well as mechanical properties [50,81,160].…”

“…Interestingly, numerical analyses presented in ref. [160] showed that the compressive modulus of the composite foams can be well predicted by micromechanic theories based on the combination of the Ishai-Cohen [177] and Gibson-Ashby models [178]. The modulus-density (volume fraction) relationship was characterized by a power-law function with exponents between 2 and 3.…”