Alginate-Based Biomaterials for Regenerative Medicine Applications

Abstract

Alginate is a natural polysaccharide exhibiting excellent biocompatibility and biodegradability, having many different applications in the field of biomedicine. Alginate is readily processable for applicable three-dimensional scaffolding materials such as hydrogels, microspheres, microcapsules, sponges, foams and fibers. Alginate-based biomaterials can be utilized as drug delivery systems and cell carriers for tissue engineering. Alginate can be easily modified via chemical and physical reactions to obtain derivatives having various structures, properties, functions and applications. Tuning the structure and properties such as biodegradability, mechanical strength, gelation property and cell affinity can be achieved through combination with other biomaterials, immobilization of specific ligands such as peptide and sugar molecules, and physical or chemical crosslinking. This review focuses on recent advances in the use of alginate and its derivatives in the field of biomedical applications, including wound healing, cartilage repair, bone regeneration and drug delivery, which have potential in tissue regeneration applications.

Keywords: alginate; biomaterials; drug delivery; regenerative medicine; tissue engineering.

Figure 1

(a) Chemical structure of alginate; (b) Mechanism of ionic interaction between alginate and divalent cations.

Figure 2

Schematic showing the temperature dependent behavior of PNIPAAm-g-alginate hydrogels. PNIPAAm = Poly(N-isopropylacrylamide)

Figure 3

Schematic showing cell-crosslinked network formation of ligand modified alginate.

Figure 4

Schematic illustration of the preparation of methacrylated alginate and photocrosslinking of methacrylated alginate.

Figure 5

Scheme of alginate-gelatin composite hydrogel via the Schiff-base reaction.

Figure 6

Illustration of the procedure for alginate gel-spheres in containing cells.

Figure 7

Illustration of the procedure for alginate solid-spheres in loading drugs.

Figure 8

Schematic illustration to show the fabricating procedures of alginate-based sponge by the freeze-drying method.

Figure 9

Illustration of electrospinning of an alginate fibrous scaffold.