Biomedical Engineering Reference
In-Depth Information
for combining with HAp [58]. Fibers of PLLA may strengthen HAp
and its good bioresorbility provides space for tissue extension.
Composite biomaterial HAp/PLLA embodies good features of each of
these biomaterials. Differences in porosity, microstructure, com-
pressive consistency as well as bioresorbility of HAp/PLLA may be
achieved by using PLLA with different mole masses [59]. The most
appropriate way of recognizing the usability of biocomposite is its
implantation into the organism.
Recently, much effort has been directed at the fabrication of
carbon nanotubes (CNTs)/polymer composites, and the characteri-
zation of their physical properties. Among them, composites
comprising CNTs and the biocompatible polymers are of special
interest due to their potential for speciic biomedical applications
[147]. Zhang et al . report the preparation of the MWCNT/poly(L-
lactide) composite and the corresponding spectroscopic (Raman)
and the microscopic (SEM, TEM) characterization [147]. The
electronic transport, thermal properties, and biocompatibility of this
composite have also been investigated. The Raman spectroscopic
analysis suggests the interaction between PLLA and MWCNT occurs
mainly through the hydrophobic C-CH 3 functional groups. The DC
conductivity of the composite increases as the MWCNT loading
is increased. Such behavior can be described by a percolation
mechanism in which a percolation threshold at about 14 wt%
MWCNT loading is observed with the maximum end conductivity of
0.1 S . cm -1 . The DSC study of the PLLA/MWCNT composite reveals
that the MWCNTs in the composite have the effect of inducing
crystallization and plasticizing the polymer matrix. The results
from the cell culture test suggest that the presence of MWCNT in the
composite inhibits the growth of the ibroblast cells.
Chen et al . have fabricated the biocompatible poly(lactic acid)
(PLA) nanoibers by using electrospinning and then adopted to
blend with other nanomaterials such as nano-TiO 2 , which have
been widely applied in biomedical and bioengineering ields, as a
potential drug carrier or protective container for biologically active
drug molecules [21]. The observations indicate that by combining
this nanocomposite with the drug accumulation of anticancer drug
daunorubicin, a broad-spectrum anticancer agent, the blends of
nano-TiO 2 and PLA nanoibers could afford promising scaffolding
for noncovalent attachment of multiple drugs, which could
 
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