HYBRID POROUS SCAFFOLDS OF BIODEGRADABLE SYNTHETIC POLYMERS AND COLLAGEN FOR TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 419

tissues and organs such as skin, cartilage, bone, trachea, bladder,
bloodvessels, nerves, etc.
Thescaffoldsusedfortissueengineeringandregenerativemedi-
cine should permit cell adhesion, promote cell proliferation and
differentiation, and be biocompatible, biodegradable, mechanically
strong, and capable of being formed into desired shapes. 5 - 7 A
number of scaffolds have been prepared from biodegradable syn-
thetic polymers such as poly(glycolic acid) (PGA), poly( L -lactic acid)
(PLLA), their copolymer of poly(lactic- co -glycolic acid) (PLGA), and
biodegradable, naturally derived polymers such as collagen and
hyaluronic acid. 8 - 10 Synthetic and naturally derived polymers have
their respective advantages and disadvantages. Biodegradable syn-
thetic polymers can easily be formed into designed shapes with
relatively high mechanical strength. However, the scaffold surface
of these polymers is relatively hydrophobic, which is not good for
cell seeding. In contrast, naturally derived polymers have specific
cell interaction peptides, and their scaffolds have hydrophilic sur-
faces,whicharebeneficialforcellseedingandcellattachment.How-
ever,naturallyderivedpolymersaretooweakmechanically.Thetwo
kinds of polymers have been hybridized to combine the advantages
of both polymers and overcome their disadvantages. This chapter
summarizes recent development of such hybrid scaffolds and their
applications to tissueengineering and regenerative medicine.
22.2 PLGA-Collagen Hybrid
Hybrid porous scaffolds of biodegradable polymers such as PGA,
PLLA, and PLGA and collagen have been prepared by introducing
collagenmicrospongesintheopeningsofskeletonsofbiodegradable
synthetic polymers (Fig. 22.1). 11 A PLGA-collagen hybrid sponge is
prepared by hybridization by introducing collagen microsponges
into the pores of a PLGA sponge (Fig. 22.2). 12 Observation of the
cross section of the hybrid sponge with a scanning electron micro-
scope (SEM) shows that collagen microsponges were formed in the
poresofthePLGAsponge.SEM-electronprobemicroanalysisofele-
mentalnitrogenindicatesthattheporesurfacesofthePLGAsponges
are coated with collagen and microsponges of collagen had formed