We show that materials with a diverse range of mech. and biol. properties can be obtained using a modular approach by simply mixing different ratios of oligocaprolactones that are either end-functionalized or chain-extended with quadruple hydrogen bonding ureido-pyrimidinone (UPy) moieties. The use of two UPy-synthons allows for easy synthesis of UPy-modified polymers resulting in high yields. Comparison of end-functionalized UPy-polymers with chain-extended UPy-polymers shows that these polymers behave distinctively different regarding their material and biol. properties. The end-modified UPy-polymer is rather stiff and brittle due to its high crystallinity. Disks made of this material fractures after s.c. implantation. The material shows a low inflammatory response which is accompanied by the formation of a fibrous capsule, reflecting the inertness of the material. The chain-extended UPy-material on the contrary is practically free of cryst. domains and shows clear flexible properties. This material deforms after in-vivo implantation, accompanied with cellular infiltration. By mixing both polymers, materials with intermediate properties concerning their mech. and biol. behavior can be obtained. Surprisingly, a 20:80 mixt. of both polymers with the chain-extended UPy-polymer in excess shows flexible properties without visible deformation upon implantation for 42 days. This mixt., a blend formed by intimate mixing through UPy-UPy interaction, also shows a mild tissue response accompanied with the formation of a thin capsule. The material does not become more cryst. upon implantation. Hence, this mixt. might be an ideal scaffold material for soft tissue engineering due to its flexibility and diminished fibrous tissue formation, and illustrates the strength of the modular approach.
|Number of pages||12|
|Publication status||Published - 2006|