18.5 Enhancing the Mechanical Properties of Natural
Polymers for CTE
While natural biomaterials such as gelatine, chitosan etc. provide good
hydrophilicity to support cell attachment, they are difficult to handle during surgical
reconstruction of heart defects. It can be overcome by use of sandwiched scaffold
wherein biomaterial of high tensile strength such as PCL is sandwiched in natural
biomaterials such as gelatine-chitosan (Pok et al. 2013). The PCL core could
provide surgical handling, suturability and high initial tensile strength, while the
gelatin-chitosan scaffold allowed for cell attachment, with pore size and mechanical
properties conducive to CMs migration and function. Similarly, Ravichandran et al.
fabricated PGS/fibrinogen, core/shell fibers with core as elastomeric PGS that
provided suitable mechanical properties comparable to that of native tissue and
shell as fibrinogen to promote cell-biomaterial interactions (Ravichandran et al.
2013b). The PCL has high mechanical strength with slow degradation rate, therefore incorporation of hybrid composite with polydioxanone fibers by electrospinning improves mechanical properties compared to PCL alone for vascular smooth
muscles generation (Pan et al. 2017). Hence, hybrid materials with tunable
mechanical properties have attracted researcher’s attention in the field of tissue
engineering. The hybrid material of polylactide with aniline tetramer shows
excellent ductility and enhanced modulus for the differentiation of myoblast to
myotubes (Xie et al. 2015). In addition, crosslinking of hybrid materials with
genipin represented lower elastic modulus suitable for soft tissue engineering
(Garnica-Palafox and Sanchez-Arevalo 2016). The first reported hybrid scaffolds
with the help of 3-D stereolithographic printing of chitosan and polyethylene glycol
diacrylate were found to have *400 kPa elastic modulus with interconnected pores
suitable for the repair of soft tissues (Morris et al. 2017).
18.6 Natural Biomaterials as Coating Materials
Natural biomaterials such as gelatine, collagen, Matrigel™, fibronectin, laminin,
bioactive glass etc. have also been used commonly to bio-functionalize the synthetic
biomaterials-derived scaffolds to enhance cell adhesion, cell-to-cell communication
and cellular interaction with scaffold (Oliver et al. 2019). Synthetic RGD has also
been used to mimic biochemical signals for cell attachment (Lambshead et al. 2018).
Most cell types attach to the biomaterials in an RGD domain-dependent manner and
therefore, synthetic RGD peptides were effecting interaction of CMs, osteocytes and
other cells with biomaterials (Hoyos-Nogues et al. 2019). CMs are also responsive to
synthetic fragments of fibronectin, vitronectin, and stromal-derived factor-1 (Liao
et al. 2018). Thus, inclusions of these synthetic sequences into biomaterial formulation are expected to improve cell adhesion and play an important role in cell
retention during dynamic cell seeding of scaffolds.
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P. Pushp and M. K. Gupta
Polymers for CTE
While natural biomaterials such as gelatine, chitosan etc. provide good
hydrophilicity to support cell attachment, they are difficult to handle during surgical
reconstruction of heart defects. It can be overcome by use of sandwiched scaffold
wherein biomaterial of high tensile strength such as PCL is sandwiched in natural
biomaterials such as gelatine-chitosan (Pok et al. 2013). The PCL core could
provide surgical handling, suturability and high initial tensile strength, while the
gelatin-chitosan scaffold allowed for cell attachment, with pore size and mechanical
properties conducive to CMs migration and function. Similarly, Ravichandran et al.
fabricated PGS/fibrinogen, core/shell fibers with core as elastomeric PGS that
provided suitable mechanical properties comparable to that of native tissue and
shell as fibrinogen to promote cell-biomaterial interactions (Ravichandran et al.
2013b). The PCL has high mechanical strength with slow degradation rate, therefore incorporation of hybrid composite with polydioxanone fibers by electrospinning improves mechanical properties compared to PCL alone for vascular smooth
muscles generation (Pan et al. 2017). Hence, hybrid materials with tunable
mechanical properties have attracted researcher’s attention in the field of tissue
engineering. The hybrid material of polylactide with aniline tetramer shows
excellent ductility and enhanced modulus for the differentiation of myoblast to
myotubes (Xie et al. 2015). In addition, crosslinking of hybrid materials with
genipin represented lower elastic modulus suitable for soft tissue engineering
(Garnica-Palafox and Sanchez-Arevalo 2016). The first reported hybrid scaffolds
with the help of 3-D stereolithographic printing of chitosan and polyethylene glycol
diacrylate were found to have *400 kPa elastic modulus with interconnected pores
suitable for the repair of soft tissues (Morris et al. 2017).
18.6 Natural Biomaterials as Coating Materials
Natural biomaterials such as gelatine, collagen, Matrigel™, fibronectin, laminin,
bioactive glass etc. have also been used commonly to bio-functionalize the synthetic
biomaterials-derived scaffolds to enhance cell adhesion, cell-to-cell communication
and cellular interaction with scaffold (Oliver et al. 2019). Synthetic RGD has also
been used to mimic biochemical signals for cell attachment (Lambshead et al. 2018).
Most cell types attach to the biomaterials in an RGD domain-dependent manner and
therefore, synthetic RGD peptides were effecting interaction of CMs, osteocytes and
other cells with biomaterials (Hoyos-Nogues et al. 2019). CMs are also responsive to
synthetic fragments of fibronectin, vitronectin, and stromal-derived factor-1 (Liao
et al. 2018). Thus, inclusions of these synthetic sequences into biomaterial formulation are expected to improve cell adhesion and play an important role in cell
retention during dynamic cell seeding of scaffolds.
630
P. Pushp and M. K. Gupta