Innovative Strategies for Tissue Engineering - Advances in Biomaterials Science and Biomedical Applications - page 299

iii. Studying material tribology and surface topography [19]. For several tissues, such as

muscles and tendons, cell organization is paramount for optimal tissue function. The
heart, for instance, works as a pumping organ, and needs to contract in a specific,
synchronized way in order to actually eject blood into body and lungs. If muscle fibers
are not synchronized, no pumping force is generated, and great deficit of function is
witnessed by the patient [60]. Tendon is a specific connective tissue composed of
parallel collagen fibers. Along with the heart, tendon constitutes another of several
tissues which depend on specific cell organization for proper function. It has been
thoroughly described in literature that tendon strength is directly linked to cell
orientation, and, following injuries, the lack of orientation of scar tissue promotes
tendon weakness, leading to repetitive lesion [61]. Tissue engineering approaches for
tendon must promote cell alignment in order to achieve significant benefit for
patients. cell alignment has been shown to be achievable and effective in promoting
tissue organization and maturation [30], as shown in Figure 2.

iv. Optimizing biomaterial degradation rate. Tissue engineering has been envisioned to

promote tissue regeneration, therefore in this context, biomaterials should be
biodegradable. Ideally, biomaterial should gradually degrade, at the same rate as
neotissue is formed.

Figure 2. Cell orientation promotes major contractile strength of construct. In order to assess cell orientation impor‐
tance for construct function, Dr. Parker`s group engineered bidimensional cardiac muscles with different micropat‐
terned surfaces in order to promote degrees of cell orientation. Confluent unaligned isotropic (A), aligned anisotropic
(B) and non confluent, 20μm spaced, parallel arrays of myocardial fibers (C) were build and studied in vitro . The cited
work showed that contractile force increases with major sarcomere alignment, as measured by peak systolic stress in
kPa (D). This panel was based on [60] and was kindly provided by Dr. Kevin Kit Parker, from Harvard University.