Advances in Collagen-based Tissue Engineering - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 217

the genes to chronic wounds and successful transfection allows the increased continu-
ous synthesis of growth factors in wounds and acceleration of cells proliferation or
angiogenesis that increases speed of healing. At application of the selected angiogenic
growth factors for example vascular endothelial cell growth factor (VEGF) basic fi-
broblast growth factor (bFGF or FGF-2) and epidermal growth factor (EGF) may be
useful for enhancing angiogenesis (Gerard et al., 2010; Lee and Shin, 2007) and in
vivo wound healing of diabetic ulcers (Choi et al., 2008). The achievement of combin-
ing high loadability with controlled release of growth factors still represents a major
challenge in the field tissue engineering (Pang et al., 2010).
Bacterial Collagen-like Protein
Predominantly, collagen-based scaffolds are constructed from bovine Type I collagen.
It has weak immunogenic tendencies and of crucial importance, it bears great resem-
blance to human collagen. The Word Heath Organization (WHO) allows the use of
bovine collagen in medical applications, providing that specified safety procedures
are adhered to. However, when substances of animal origin are used it is not impos-
sible for transmission of pathogens to occur, mainly BSE and TSE (animal transmit-
table spongio-encephalitis), from infected animal to man. The researches believe that,
although the risk is small, it is appropriate for tissue engineering to develop scaffolds
based on alternative to animal's collagen. Significant progress has been made in pro-
duction of recombinant human collagen in yeasts to circumvent this and other issues.
However, the use of yeast systems is complicated and difficulties in achieving large
scale production. Recently, the new realistic prospect of a remedy has appeared from
the latest advances in production of bacterial collagens (Peng et al., 2010). There is
a conviction that bacterial collagens are an excellent source of collagen for use as
biomaterials and as a scaffold for tissue engineering. The recombinant bacterial col-
lagen can be produced in large quantities in E. coli without any animal contamina-
tion. In particular, it is non-immunogenic, supports cell attachment, can be made with
additional functional domains and can be fabricated into fibrous structures and into
formats such as sponges suitable for wound repair or other medical applications.
Neural tissue eNGiNeeriNG
Damage of the central nervous system (nerves of spinal cord) can be caused by disease
or trauma and often results in paralysis, which at present can not be cured. Every year,
more than 11,000 individuals sustain spinal injury in the USA. These are mostly young
men, median age 26. Of the quarter of a million people living in the USA after spinal
cord injury, nearly half have irreversible loss of neurologic function below the level of
injury (with either lower limbs or all four limbs paralyzed). (Madigan et al., 2009). It
is known, that in Europe it is comparable number but complete data is not available.
The aim of a lot researches is to pave the way for reversing this loss of neurologic
functions, which is still perceived as “irreversible”.
The new, realistic prospect of a remedy has emerged from the latest advances in
tissue engineering. Tissue engineering progresses by applying newly developed scien-
tific methods and concepts to techniques of regeneration of lost, damaged or diseased