Bioelastic Materials as Chemomechanically Transducing (“Smart”) Matrices for Drug Delivery
For biodegradable drug delivery systems, control of hydration can be a key to rate of degradation. When beginning with drug-doped condensed matrices, controlling the rate of hydration (swelling) can then become the key to drug release. One approach is to use responsive polymers coupled to chemical clocks with selectable half-lives. Polymers that exhibit chemically modulable inverse temperature transitions are an ideal material for such drug delivery matrices and elastometric polypeptides form such matrices. The chemical clocks can be peptide sequences containing Asn or Gln residues (or other suitably unstable chemical groupings) which, depending on the hydrophobicity of adjacent residues, can exhibit half-lives from days (or less) to decades. The half-lives of the [CONH2→COO-] reaction can be further shifted by hydrophobic tertiary structure. It is the rate of carboxylate anion or other the polar species formation which would then control the extent of swelling and rate of degradation.
KeywordsPermeability Hydration Albumin Titration Carboxylate
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