Integrated strategy using ionic liquids for the design and processability of natural polymeric architectures for regenerative medicine

Integrated strategy using ionic liquids for the design and processability of natural polymeric architectures for regenerative medicine

Silva SS, Duarte ARC, Santos TC, Cerqueira MT, Marques AP, Oliveira JM, Mano JM, Reis RL

Introduction. Natural polymers are adequate renewable resources for the design and processability of well-defined architectures for several applications, including tissue engineering. Combinations of polysaccharides and proteins may mimic the naturally occurring environment of certain tissues, providing an optimum substrate for tissue growth and regeneration. The main goal of this work was to apply the green chemistry principles, represented by the use of ionic liquids (ILs), and biorenewable sources, which combined with well-known or less conventional technologies can provide new ways to obtain controlled polymeric architectures (e.g.macro/nano porous structures, hydrogels) suitable for regenerative medicine.

Methods. To design the materials structures, chitosan-silk/IL and chitin/IL solutions were processed as hydrogels/sponges and macro/nano structures using gelation/freeze-drying and supercritical fluid technology, respectively. The preparation conditions were adjusted according to each technique/method. The ability of the developed materials to support adhesion and proliferation of human osteoblastic-like cells (SaOs-2) and dermal fibroblasts (hDFs) was assessed up to 21 days of cell culture.

Results. The chitin porous structures (CPS) showed interesting features such as very low density (0.039 g/L to 0.063 g/L), porosity between 84 and 90% and a heterogeneous porous formation with pores from micro-to nanoscale and cristallinity about 21%. Chitosan/silk-based hydrogels (CSF) showed a soft and rubbery consistency, microporous surface and viscoelastic behavior. The in vitro biological performance of both structures revealed their positive influence in adhesion, viability and proliferation of cell SaOs-2 (porous structures) and hDFs (hydrogels) for the studied culturing time.

Conclusions. The findings suggest that the IL platform provides a versatile approach to obtain different polymeric architectures with interesting properties. Both CSF and CPS structures demonstrated their potential to be used as wound dressings or as supports for skin tissue engineering.

Acknowledgements. Silva SS, JM Oliveira, AR Duarte thank the Portuguese Foundation for Science and Technology (FCT) for their Post doc fellowships.

Keywords: ionic liquids, natural polymers, polymeric architectures, tissue engineering.