HYBRID POROUS SCAFFOLDS OF BIODEGRADABLE SYNTHETIC POLYMERS AND COLLAGEN FOR TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 431

collagenspongeformedinsidethemoldandthatitwascross-linked
with the nylon membrane by forming collagen fibers that passed
through the interstices of the nylon membrane. The climbing col-
lagen fibers prevented the collagen sponge from detaching from
the mold. Without the nylon membrane, the collagen sponge that
formed inside the polyethylene mold shrank and detached from the
mold. A polystyrene cylinder served as a support to maintain the
shape of the collagen sponge. The nylon mesh helped in attaching
thecollagenspongetothemoldandpreventingthecollagensponge
from shrinking. Human bone marrow-derived MSCs were seeded
in the collagen sponge and cultured in a proliferation medium for
one week. Cell-seeding e ciency was 95.0 ± 2.7%. The nylon mem-
brane prevented leakage of the seeded cells. The MSCs adhered to
the collagen sponge and were homogeneously distributed through-
out the sponge. During culture, the cells proliferated and secreted
extracellular matrices that filled the voids in the sponge. When this
leak-proof scaffold was used for in vivo implantation, the collagen
spongeinthecenterofthenylonmeshmoldmustbedrilledoutand
thenimplanted.Acup-shapedPLLAspongehasbeenusedtoreplace
thenylonmeshmoldtoconstructaleak-proofbiodegradablehybrid
scaffold.
The leak-proof PLLA-collagen hybrid scaffold was prepared by
introducingacollagenspongeintothecenterofacup-shapedskele-
ton of biodegradable synthetic polymers. The PLLA sponge cup was
prepared using the porogen leaching method using a mold. The
PLLA sponge cup was then filled with an aqueous collagen solu-
tion by introducing the collagen solution into the pores of the cup
and the central space. The collagen solution-filled PLLA sponge cup
was freeze-dried and cross-linked to form a cylinder-type PLLA-
collagen hybrid sponge. The PLLA-collagen hybrid sponge had the
same shape as the PLLA sponge cup. A collagen sponge was formed
in the center of the PLLA sponge cup, and collagen microsponges
wereformedintheporesofthewallandbottomofthePLLAsponge
cup.Thehybridspongewascomposedoftwoparts,thecentralcolla-
genspongeandthesurroundingPLLA-collagenspongecup.Thecen-
tral collagen sponge was connected with the collagen microsponges
in the pores of the wall and bottom of the PLLA sponge cup by col-
lagen fibers that passed through the interstices of the PLLA sponge.