Investigating the morphological, mechanical and degradation properties of scaffolds comprising collagen, gelatin and elastin for use in soft tissue engineering

Abstract

Collagen-based scaffolds can be used to mimic the extracellular matrix (ECM) of soft tissues and provide support during tissue regeneration. To better match the native ECM composition and mechanical properties as well as tailor the degradation resistance and available cell binding motifs, other proteins or different collagen types may be added. The present study has explored the use of components such as gelatin or elastin and investigated their effect on the bulk physical properties of the resulting scaffolds compared to those made from pure collagen type I. The effect of altering the composition and crosslinking was evaluated in terms of the scaffold structure, mechanical properties, swelling, degradation and cell attachment. Results demonstrate that scaffolds based on gelatin had reduced tensile stiffness and degradation time compared with collagen. The addition of elastin reduced the overall strength and stiffness of the scaffolds, with electron microscopy results suggesting that insoluble elastin interacts best with collagen and soluble elastin interacts best with gelatin. Carbodiimide crosslinking was essential for structural stability, strength and degradation resistance for scaffolds of all compositions. In addition, preliminary cell adhesion studies showed these highly porous structures (pore size 130-160 μm) to be able to support HT1080 cell infiltration and growth. Therefore, this study suggests that the use of gelatin in place of collagen, with additions of elastin, can tailor the physical properties of scaffolds and could be a design strategy for reducing the overall material costs.

Depth-controlled laser-induced jet injection for direct three-dimensional liquid delivery

“…Here, to investigate direct three-dimensional liquid delivery, the receiver substrate consists of a 300 μm thick soft gelatin substrate. Gelatin, as an inert and biocompatible material [26], has been used as a soft tissue model [3,13,27] or as a scaffold material for soft tissue-engineering applications [28][29][30]. Interestingly, gelatin exhibits Bingham plastics rheological properties.…”

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“…Synthetic hydrogels such as polyethylene glycol (PEG) or polycaprolactone (PCL) can be used either alone or in tandem with other scaffolding biomaterials to produce an ideal ECM for cellular growth [36,40]. Studies have shown how gelatin or elastin can be incorporated to decrease biodegradability and improve structural strength [35]. Additionally, growth factors and enzyme-specific peptides can also be incorporated to influence biodegradability and matrix permeability in a similar way to previously discussed natural scaffolds [36,39,40] (Figure 2).…”

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“…By adding appropriate growth factors and creating the proper conditions, cells can grow on these scaffolds and regenerate the tissue that was previously damaged [34]. The key requirements for a successful biological scaffold are: topographical characteristics that mimic native tissue, a porous framework that allows cell and nutrient permeability, non-toxic biodegradability, biocompatibility with natural tissues and an economical manufacturing process [35]. Table 2 illustrates the main types of scaffolds used in tissue engineering and how they differ [36].…”