Lecture 4 Degradable Materials with Biological Recognition (part II).pdf

Molecular Principles of Biomaterials Spring 2003
Lecture 4: Degradable Materials with Biological Recognition (part II)
Last time: Biological recognition in vivo
Engineering biological recognition of biomaterials: adhesion/migration peptides
Today: Engineering biological recognition of biomaterials: enzymatic recognition and cytokine
signaling
Reading: . Sakiyama-Elbert and . Hubbell, ‘Functional Biomaterials: Design of Novel
biomaterials,’ Annu. Rev. Mater. Sci. 31, 183-201 (2001)
. Schense et al., ‘Enzymatic incorporation of bioactive peptides into fibrin matrices
enhances neurite extension,’ Nat. Biotech. 18, 415-419 (2000)
Supplementary Reading: ‘The Extracellular Matrix,’ pp. 1124-1150, Molecular Biology of the Cell, Lodish et al.
Recognition of Biomaterials by Proteases: Engineering Enzyme-mediated degradation of
polymers
Basic concept: include peptide sequences in the polymer chain which are cleaved by enzymatic activity of serum
proteins/cellular secreted products (active breakdown) [hydrolysis active but slow...]
• Amide bond -(NH)-(CO)- provides natural hydrolytic mechanism for degradation, but breaks down very slowly in
physiological conditions
Remodeling enzymes in vivo:
1) binding of target by enzyme
2) specific site cleavage
• What is enzymatic cleavage used for in vivo?1 (Reading Ch.