SYNTHESIS AND IN VITRO/IN VIVO RESPONSE TO PEPTIDEPOLYMER CONJUGATES - Biologically-Responsive Hybrid Biomaterials - page 128

studies report in vitro findings and the impact of the complex and dynamic
interaction between blood proteins and a variety of host cells on the RGD
presenting surface is even less understood. Even in in vitro systems the cause and
effect based mechanisms behind cell-material interaction (i.e. enhance adhesion,
proliferation and ECM production, etc.) are yet to be clearly deciphered and
remain critical to the ultimate goal of directed host response. And though
peptides are more stable than the whole protein, they are not exempt from
thermal instability and hydrolysis and are thus subject to short shelf lives.
Peptides can also be costly to synthesize and may be impractical for large scale
treatments, but with rapid developments in recombinant DNA technologies that
allow the synthesis of these sequences, overcoming the hurdle of high scale up
cost is becoming more plausible. The biggest challenge will still be controlling
the dynamic and spatial arrangement of multiple signals and ultimately
translating this controlled surface into directed host response.
With current developments in our increasingly sophisticated understanding
of protein structure-function through technologies such as crystallography, the
trend in peptide conjugated systems is shifting toward peptide conjugated natural
polymers. Natural biopolymers such as chitosan, collagen and hyaluronic acid
are rapidly gaining interest, and the literature on peptide conjugated natural
polymers is growing at a faster rate than peptide conjugated synthetic polymer
systems. However, synthetic polymers are more robust than natural polymers and
continue to be a more prevalent application in the clinical setting, and thus the
endeavor to impart biological activity onto polymer surfaces to create uniquely
advantageous biomaterials will continue.
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