Table 1 Natural materials for cartilage tissue engineering. Advantages and disadvantages
From: Current concepts and perspectives for articular cartilage regeneration
Natural origin scaffolds | Advantages | Disadvantages |
|---|---|---|
Hyaluronic acid | Anionic, non-sulfated glycosaminoglycan (GAG) is present in cartilage ECM. Supports cell attachment through surface receptors like CD44ECM | Poor mechanical properties, rapid degradation |
Chondroitin sulfate | Sulfated GAG is present in cartilage ECM with anti- inflammatory activity, and a role in cell signaling. Easy to be functionalized | Poor mechanical properties, rapid degradation |
Alginate | Negatively charged polysaccharide extracted from brown algae and bacterial sources. High functionality, fast cross-linking, low cost, injectable for bioprinting, structural similarity to GAGs | Poor mechanical strength, low cell- matrix interaction, varying levels of purity due to source variability, immunogenicity |
Agarose | A marine polysaccharide obtained from seaweed. It presents excellent biocompatibility, good stiffness and viscoelasticity. High functionality, thermoreversible gelation, low cost, structural similarity to GAGs | Limited mechanical performance, low bioactivity, poor cell attachment |
Chitosan | An amino polysaccharide polymer derived from chitin and the wastes of the seafood industry. Biocompatible and biodegradable. It possesses antibacterial ability | Poor water solubility in physiological conditions, potential allergenic risks, inferior mechanical properties, low cell adhesiveness, and potential allergenic reactions due to its origin |
Gellan gum | A linear negatively charged polysaccharide produced by the Sphingononas group bacteria; pH and temperature responsiveness, structural similarity to GAGs | Weak mechanical strength, poor stability, low bioactivity, relatively high gelation temperature, small temperature window |
Collagen | The main protein component in natural cartilage, displays great biocompatibility and biodegradation without causing inflammation | Poor mechanical properties, potential of immunogenicity, high cost, limited sterilizability |
Gelatin | A derivative of collagen by partial hydrolysis with much lower antigenicity Biologically active for cellular interaction, low immunogenicity in comparison to collagen, ease of processing and functionalization | Poor mechanical properties, rapid degradation, low thermal stability |
Silk fibroin | The major protein component of natural silk. High mechanical strength, low immunogenicity, morphologic flexibility, good sterilizability, usable for cartilage bioprinting, easily available, biocompatible, biodegradable | Source variability, low biodegradability |
Fibrin | Fibrin is a blood protein, well known for its role in clot formation, justifying its use in clinical practice as a hemostatic or a sealant agent. Hydrogels can be prepared from fibrinogen by the enzymatic treatment of thrombin; the advantages are excellent biocompatibility and biodegradability | Weak mechanical properties |
Cellulose | One of many polymers found in nature, may enter the composition of carboxymethyl cellulose, and in turn, hydrogel by specific processes | Low integration. No degradability |