Page - (000246) - in Biomedical Chemistry: Current Trends and Developments

Figure 3.1.13: A) Applications of cell-penetrating peptides as molecular delivery vehicles. B) Intracellular delivery of CPP-cargo complexes (specific internalization pathways have not been fully elucidated and seem to depend on the specific nature of the CPP and the cargo attached to it). Adapted from (Capolovici, 2014; Wang, 2014). 3.1.3.3 Peptides: Scaffolding Materials in Tissue Engineering 3.1.3.3.1 Peptide-based Biopolymers Peptides provide an extensive repertoire of signals that can be used to synthetically recreate complex biological processes required for tissue regeneration, such as enabling naturally occurring enzyme-mediated degradation, specific binding of biomolecules, or directing cell adhesion, proliferation and differentiation. Therefore, peptides represent attractive functional and structural building blocks to create versatile materials (Chan & Mooney, 2008; Smith, 2011). The use of peptide therapeutics is expected to increase in the near future not only as the active ingredient, but also as new conjugated forms with polysaccharides or synthetic polymers to improve potency and specificity (Vlieghe, 2010). In this context, peptides can be used as targeting moieties, as carriers to provide transport across cellular membranes, and to modify the bioactivity of the original compound/material. In the field of biomaterials, peptides have also been extensively used as cell-instructive motifs with different roles, namely to promote cell-adhesion to otherwise non-adhesive polymers, as well as proliferation and differentiation (Collier & Segma, 2011; Wojtowicz, 2010). Finally, peptides by themselves are paving the way as new biomaterials. This is the case for a new class of materials named self-assembling peptides (SAPs), which self-assemble into nanofiber-like hydrogen bond networks under physiological concentrations of salt solutions and have found numerous applications as three-dimensional matrices in the biomedical field (Collier & Segma, 2011; Matson & Stupp, 2012). 3.1.3.3.2 Strategies to Create Scaffolds as Instructive Extracellular Microenvironments for Tissue Engineering - Peptide-conjugated