Table 1 Natural biodegradable polymers commonly used in tendon/ligament regeneration

Collagen

Biocompatible; major component of ligaments [7]; reasonable mechanical properties [9]

Poor mechanical strength; [7] risk of immunogenicity; [27] fast degradation [42]

Silk

Good mechanical properties; slow rate biodegradation [9]; loses its strength after 1 year, in vivo [33]

Limited cell adhesion [7]

Alginate

Biocompatible ECM component; can be in sponge or hydrogel form [7]; proper substrate for fibroblasts growth and collagen type I production [9]

Lacks mechanical properties [7]

Hyaluronic acid

Biocompatible; can be in sponge or hydrogel form [7]

Natural form with very short degradation time [43]

Chitosan

Biocompatible; can be in sponge or hydrogel form [7]; proper substrate for fibroblasts growth and Col type I production [9]

Lacks mechanical properties [7]