Smart controlled preparation of multilayered hydrogel for releasing bioactive molecules

We focused on layer-by-layer (LBL) method which has emerged as a versatile and efficient technique. The preparation of multilayered hydrogel can resolve the problems. We fabricated and characterized pH-controlled preparation of polymer multilayer via LbL method on titanium alloy surface for releasing the growth factor. To achieve this purpose, we synthesized water-soluble phospholipid polymer (PMDV) having both N,N-dimethylaminoethyl methacrylate (DMAEMA) as pH-sensitive unit and 4-vinylphenylboronic acid (VPBA) moiety as sugar binding units. To construct the multilayered hydrogel, alginate (ALG), which possesses a polysaccharide comprised of two repeating carboxylated monosaccharide units was used. We could construct multilayered hydrogel easily by using two interaction types. The first is the electrostatic interaction between positively charged DMAEMA and negatively charged carboxyl group of ALG, and the second is the covalent bonding between VPBA and diol of ALG. Multilayered PMDV and ALG hydrogel was characterized by contact angle measurement, surface plasmon resonance. The results demonstrate that the surface composition of the multilayered hydrogel can be simply constructed via LbL process and VEGF release can be released during 1 week. We expect this system will be applied in biomedical and drug delivery system.