Preparation and Characterization of Shape Memory Polymer Scaffolds via Solvent Casting/Particulate Leaching

Abstract

Purpose: Porous Shape Memory Polymers (SMPs) are ideal candidates for the fabrication of defect fillers, able to support\ud tissue regeneration via minimally invasive approaches. In this regard, control of pore size, shape and interconnection is required\ud to achieve adequate nutrient transport and cell ingrowth. Here, we assessed the feasibility of the preparation of SMP\ud porous structures and characterized their chemico-physical properties and in vitro cell response.\ud Methods: SMP scaffolds were obtained via solvent casting/particulate leaching of gelatin microspheres, prepared via oil/water\ud emulsion. A solution of commercial polyether-urethane (MM-4520, Mitsubishi Heavy Industries) was cast on compacted\ud microspheres and leached-off after polymer solvent evaporation. The obtained structures were characterized in terms of\ud morphology (SEM and micro-CT), thermo-mechanical properties (DMTA), shape recovery behavior in compression mode,\ud and in vitro cytocompatibility (MG63 Osteoblast-like cell line).\ud Results: The fabrication process enabled easy control of scaffold morphology, pore size, and pore shape by varying the gelatin\ud microsphere morphology. Homogeneous spherical and interconnected pores have been achieved together with the preservation\ud of shape memory ability, with recovery rate up to 90%. Regardless of pore dimensions, MG63 cells were observed\ud adhering and spreading onto the inner surface of the scaffolds obtained for up to seven days of static in vitro tests.\ud Conclusions: A new class of SMP porous structures has been obtained and tested in vitro: according to these preliminary\ud results reported, SMP scaffolds can be further exploited in the design of a new class of implantable devices

Thermally-responsive biopolyurethanes from a biobased diisocyanate

“…Short-term assays give information about the cell response in a sterilized material with respect to the control in culture conditioned medium [36][37][38]. Fig.…”

Porous shape memory polymers: Design and applications

“…å ( T ) is the recovered deformation as a function of temperature, å p is the final deformation, and å m is the strain rate. Similarly, eq 2 calculates the shape recovery behavior as a function of time ( R r ( t )) at a constant temperature …”

Scaffolds with shape memory behavior for the treatment of large bone defects

“…Also biocompatible gels obtained from acrylic derivatives or gelatin exhibiting cells stimulation effect have been reported . However, for formation of such types of the scaffolds, almost solely the cross‐linked polymers are used …”

“…12,13 Also biocompatible gels obtained from acrylic derivatives or gelatin exhibiting cells stimulation effect have been reported. [14][15][16][17] However, for formation of such types of the scaffolds, almost solely the cross-linked polymers are used. [18][19][20] Successful attempt to develop a scaffold with a memory shape behavior to fill a bone defect 20 related to thermoresponsive behavior of scaffolds prepared via photocrosslinking of poly(e-caprolactone) (PCL) diacrylate and exhibiting superior bioactivity is especially interesting.…”