Biomedical Engineering Reference
In-Depth Information
inducers of bone formation, which is mainly responsible for bone
morphogenetic proteins and several growth factors, including IGF
and TGF- β 1inDBPs. 26
In this study, we observed that DBP hybrid PLGA materials did
not significantly affect the viability of HL-60 cells during 3D in
vitro culture; however, their inflammatory response to DBP hybrid
polymeric materials was obviously reduced. The probable cause
for these results is that TNF-
α
expression may be strongly sup-
pressed by bioactive substances released from DBPs; this pattern
wasenhancedwithanincreaseinthecontentofDBPsinPLGAfilms,
whichcanresultinsuppressionoftheIL-1
β
expressionthatreduces
proliferation andfibrous capsular formation of fibroblasts.
DBP/PLGA materials may have more mechanical stability
compared with PLGA materials without DBPs, which can led to
decreased production of implant debris and reduction of tissue
response. Whether this reduction of foreign body reaction occurs
because the bioactive molecules released from DBPs induced sup-
pression of local inflammation or DBP-impregnated PLGA materi-
als provided a favorable surface or rigid structural support to cell
remains to bedetermined.
In this study, we have shown that by impregnating DBPs in
the PLGA materials, the inflammatory reaction could be effectively
reduced in vivo and in vitro . This result suggests that hybridization
ofnaturalmaterialssuchasDBPsissuitableforcontrolofanadverse
tissue reaction of polymericmaterials shown in vivo .
16.4 The Effect of SIS on the Host Tissue Response to
PLGA/SIS Hybrid Scaffolds
SIS consists of more than 90% types I and III collagen, plus
a wide variety of cytokines, including basic fibroblast growth
factor (bFGF), transforming growth factor- β (TGF- β ), epidermal
growthfactor(EGF),vascularendothelialgrowthfactor(VEGF),and
IGF-1, as well as GAGs, fibronectins, chondroitin sulfates, heparins,
heparin sulfates, and hyaluronic acids. 27 These constituents are
expected to facilitate the function of SIS as a tissue engi-
neering scaffold by supporting cell attachment, proliferation,
 
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