Application of Collagen Scaffold in Tissue Engineering: Recent Advances and New Perspectives

Abstract

Abstract:Collagen is the main structural protein of most hard and soft tissues in animals and the human body, which plays an important role in maintaining the biological and structural integrity of the extracellular matrix (ECM) and provides physical support to tissues. Collagen can be extracted and purified from a variety of sources and offers low immunogenicity, a porous structure, good permeability, biocompatibility and biodegradability. Collagen scaffolds have been widely used in tissue engineering due to these excellent properties. However, the poor mechanical property of collagen scaffolds limits their applications to some extent. To overcome this shortcoming, collagen scaffolds can be cross-linked by chemical or physical methods or modified with natural/synthetic polymers or inorganic materials. Biochemical factors can also be introduced to the scaffold to further improve its biological activity. This review will summarize the structure and biological characteristics of collagen and introduce the preparation methods and modification strategies of collagen scaffolds. The typical application of a collagen scaffold in tissue engineering (including nerve, bone, cartilage, tendon, ligament, blood vessel and skin) will be further provided. The prospects and challenges about their future research and application will also be pointed out.

Hydroxyapatite nanowire/collagen elastic porous nanocomposite and its enhanced performance in bone defect repair

“…[16][17][18] Moreover, collagen, as the organic constituent of the bone extracellular matrix, is a promising biomaterial owing to its excellent biocompatibility, cell affinity and biodegradability. [19][20][21] Consequently, the HAP/ collagen (HAP/Col) composite scaffolds can chemically and structurally mimic the natural bone, and have excellent bioactivity, biodegradability and osteoinductive activity. 11,13,22 So far, the biomimetic HAP/Col composite scaffolds with high porosity are typically fabricated via lyophilisation, which is benecial for cell inltration, neovascularization and new bone ingrowth.…”

Application of minimally invasive injectable conductive hydrogels as stimulating scaffolds for myocardial tissue engineering

“…Using collagen for tissue engineering applications has many merits such as biocompatibility, biodegradability, suitable permeability and low immunogenicity. Conversely, it is found that collagen suffers from poor mechanical properties …”

A thermoreversible, photocrosslinkable collagen bio-ink for free-form fabrication of scaffolds for regenerative medicine

“…Without considerable crosslinking, type-I collagen has relatively weak mechanical properties and is difficult to handle or fabricate compared to competing synthetic or modified polymers 17 . Type-I collagen forms highly ordered D-banded fibers at physiological conditions that are vital for the natural presentation of bioactive epitopes and for providing anisotropic strength and stiffness, and it requires high concentrations or crosslinking to match properties of tissues 18,19 . These properties can significantly complicate 3D printing when using collagen as bio-ink, especially forms of nozzle-based 3D printing 18–21 .…”

“…Type-I collagen forms highly ordered D-banded fibers at physiological conditions that are vital for the natural presentation of bioactive epitopes and for providing anisotropic strength and stiffness, and it requires high concentrations or crosslinking to match properties of tissues 18,19 . These properties can significantly complicate 3D printing when using collagen as bio-ink, especially forms of nozzle-based 3D printing 18–21 . Alternatively, type-I collagen can be cast in specific geometries, but this requires the use of a negative mold to construct the tissue of interest 3,4,22 , which can delay treatment for the patient due to increased processing times for scaffold customization, a major benefit of 3D printing.…”