A poloxamine-polylysine acrylate scaffold for modular tissue engineering.

A new polymer, poloxamine-polylysine acrylate (PPA), was synthesized for tissue-engineering applications. Polylysine was used to confer endothelial cell attachment properties to the poloxamine-based polymer, while the acrylate groups made it photo-cross-linkable. The PPA polymer was synthesized in three reaction steps. (1) Polylysine was acrylated using N-hydroxysuccinimide acrylic acid ester and the reaction product was characterised by (1)H-NMR. (2) The hydroxyl groups on poloxamine were activated by tresylation with tresyl chloride and the reaction product (tresylated poloxamine) was characterised by ICP-AES for sulphur content. (3) The acrylated polylysine was reacted with the activated poloxamine to obtain the final product, poloxamine-polylysine acrylate. The final product was characterised by CHN elemental analysis. Aqueous solutions containing a mixture of PPA and poloxamine methacrylate were photo-cross-linked by exposure to a 365 nm UV light source in the presence of a photoinitiator to obtain hydrogels. The synthesized PPA polymer enhanced endothelial cell adhesion on poloxamine-based, photo-cross-linked hydrogel scaffolds. The same synthesis methods can be used in the future to introduce other desired functions (through other peptides) into the scaffold biomaterial.