Biomedical Engineering Reference
In-Depth Information
The chitosan nanofiber has also been studied as a bone
regenerative matrix. As a degradable and nontoxic polysaccharide
biopolymer, chitosan has been developed into nanofibers by elec-
trospinning. In particular, a chitosan solution should be prepared
in acidic solvents. Shin
et al
. produced the chitosan nanofiber for
use as a guided bone regeneration membrane in dentistry. The
electrospun membrane showed good osteoblast responses, such as
bone-associated gene expressions, and formed new bone in a rab-
bitcalvariumdefectafter4weeksofimplantation.
22
Thesilkfibroin
nanofiber has also been developed as a bone cell matrix.
23
Silk
fibroin is known to be cell compatible and biodegradable and has
minimal inflammatory reaction.
23
Silk nanofibers electrospun with
sizes of
∼
500 nm to 1
μ
m were shown to guide the adhesion and
growth of BMSCs
23
and osteoblasts.
24
14.3.2
Bioactive Inorganics
Electrospinning of inorganics with various compositions has been
well documented in many areas. For the tissue regeneration area,
biocompatible compositions should first be considered. As one cri-
terion required for bone regenerative materials, the “bone bioac-
tivity” is considered, which generally means the ability to form a
directbondwithnativebonetissuethroughaninterfacecontaininga
bone mineral-like phase. At the bone-bioactive interface, a series of
biological reactions involved in the bone formation are significantly
favored and stimulated. Currently available bone-bioactive inorgan-
icsincludecalciumphosphatesandbioactiveglasses/glassceramics,
andthesearethefascinatingchoicesofmaterialsforelectrospinning
nanofibers. Although there have been significant levels of work on
inorganicnanofibers,verylittlehasbeendocumentedoninorganics
withbone-bioactivecompositions.
Onechallengingworkhasrecentlybeenperformedonthegener-
ationofbioactiveglassnanofibersbyelectrospinning.
25
Silica-based
sol-gel glass with a bioactive composition (70SiO
2
·
25CaP
·
5P
2
O
5
)
was successfully produced with the help of a poly(vinyl butyral)
binder in an ethanol-water-based solvent. Following heat treatment
at 700
◦
C, a well-developed nanofibrous web maintaining the ini-
tial morphology was produced. The fiber size ranged from tens
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