Biodegradable shape memory polymer foams with appropriate thermal properties for hemostatic applications

Abstract

Shape memory polymer (SMP) foams are a promising material for hemostatic dressings due to their biocompatibility, high surface area, excellent shape recovery, and ability to quickly initiate blood clotting. Biodegradable SMP foams could eliminate the need for a secondary removal procedure of hemostatic material from the patients’ wound, further facilitating wound healing. In this study, we developed hydrolytically and oxidatively biodegradable SMP foams by reacting polyols (triethanolamine or glycerol) with 6‐aminocaproic acid or glycine to generate foaming monomers with degradable ester bonds. These monomers were used in foam synthesis to provide highly crosslinked SMP foam structures. The ester‐containing foams showed clinically relevant thermal properties that were comparable to controls and excellent shape recovery within eight min. Triethanolamine‐based ester‐containing foams showed interconnected porous structure along with increased mechanical strength. Faster hydrolytic and oxidative biodegradation rates were achieved in ester‐containing foams in comparison to controls. These biodegradable SMP foams with clinically applicable thermal properties possess great potential as an effective hemostatic device for use in hospitals or on battlefields.

Designing Biodegradable Shape Memory Polymers for Tissue Repair

“…By creating ester containing trifunctional monomers and incorporating them into their previously synthesized PCLpolyurethane foams, a new class of biodegradable foams was created giving rise to a range of tissue engineering and regenerative medicine applications ( Figure 12). [64] Natural Oils and Natural Oil Copolyester Urethanes: Plant [65,66] and animal [67] based natural oils have also been used in the development of thermosetting SMP networks. The use of natural oils is largely driven by the renewable sourcing and low cost.…”

“…Adapted with permission. [64] Copyright 2020, Wiley Periodicals, Inc. Figure 19. Hydrolytic degradation of biodegradable SMPs in phosphate buffered saline (PBS, pH = 7.0 at 37 °C).…”

“…By creating ester containing trifunctional monomers and incorporating them into their previously synthesized PCL‐polyurethane foams, a new class of biodegradable foams was created giving rise to a range of tissue engineering and regenerative medicine applications ( Figure ). [ 64 ]…”

“…Adapted with permission. [ 64 ] Copyright 2020, Wiley Periodicals, Inc. E) PCL‐TEA‐Gly soft segment and HDI hard segment polyurethane foams after 72 days of degradation. Adapted with permission.…”

Anisotropy Effects in the Shape‐Memory Performance of Polymer Foams

“…Very recently, biodegradable SMP foams with clinically applicable thermal properties and the ability to quickly initiate blood clotting are discussed as an effective hemostatic device. [ 11 ] Concerning the actual foaming process, in polyurethane‐based SMP foams water is applied as blowing agent. [ 12,13 ] Another foaming technology uses supercritical carbon dioxide (scCO 2 ).…”