SYNTHETIC/NATURAL HYBRID SCAFFOLD FOR TISSUE REGENERATION - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 333

films. Similarly, IL-1 β mRNA expression decreased markedly with
40% and 80% SIS/PLGA films compared with PLGA films.
TNF- α playsaroleofinflammatoryresponsethatactivatesleuko-
cytes, enhances adherence of neutrophils and monocytes, promotes
the migration of inflammatory cells into the intercellular space,
and triggers local production of other pro-inflammatory cytokines
such as IL-1 . 25 TNF- , which are potent stim-

ulators of fibroblast growth. 28 Therefore, temporospatial expres-
sion of these pro-inflammatory mediators allows fine-tuning of the
inflammatory response. 29 SIS has been reported as a biocompat-
ible inducer of cell growth, which is mainly responsible for sev-
eral growth factors, as we discussed earlier. 27 In this study, we
observed that their inflammatory response to SIS hybrid polymeric
materials was obviously reduced. The probable cause for these
results is that TNF- α expression may be strongly suppressed by
bioactive substances released from SIS; this pattern was enhanced
withanincreaseinthecontentofSISinPLGAfilms,whichcanresult
in suppression of the IL-1 β and IL-6 expression, which reduces pro-
liferation and fibrous capsular formation of fibroblasts (data not
shown).

β α

, IL-6, and IL-1

β

16.5 Conclusions and Outlook

Tissueengineering,includingregenerativemedicine,showstremen-
douspotentialasarevolutionaryresearchpush.Also,manysuccess-
ful results have reported the potential for regenerating tissues and
organs such as skin, bone, cartilage, nerves of peripheral and cen-
tral nervous systems, tendon, muscle, cornea, bladder and urethra,
and liver, as well as composite systems like the human phalanx and
joints, on the basis of scaffold biomaterials from polymers, ceramic,
metal,composites,andtheirhybrids.Theprerequisitephysicochem-
ical properties of scaffolds are (i) to support and deliver for cells,
(ii) to induce, differentiate, and conduit tissue growth, (iii) to tar-
get the cell adhesion substrate, (iv) to stimulate cellular response,
(v) to act as a wound-healing barrier, (vi) to be biocompatible and
biodegradable,(vii)toensurerelativelyeasyprocessabilityandmal-
leability into desired shapes, (viii) to be highly porous with large
surface/volume, (ix) to have mechanical strength and dimensional