Biomedical Engineering Reference
In-Depth Information
penetration into electrospun scaffolds. Pham et al. 39 combined
electrospun polycaprolactone (PCL) nanofibers with electrospun
PCL microfibers to form composite scaffolds. In this study the
diameter of the microfibers could be tuned between 2 and 10
microns, while the nanofibers were 600 nm in diameter. The
authors showed histological cross sections of the scaffolds and
quantitatively characterized cell distribution. Unfortunately, they
found that cells did not spontaneously migrate into their scaf-
folds, and the authors had to employ medium perfusion with
a bioreactor to achieve a uniform cell distribution. The use of
larger microfibers has also been considered. Marins et al . 40 con-
structed scaffolds with alternating layers of 400-1,400 nm elec-
trospun nanofibers and 300-micron melt-extruded microfibers for
bone tissue applications. Although they did not explicitly exam-
ine cell distribution within their resultant scaffolds, they reported
increases in both cell number and alkaline phosphatase activity
with the incorporation of nanofibers. Finally, the laboratories of
Drs. Gatenholm (Chalmers University, Sweden 41 ) and Freeman (Vir-
giniaTech,USA,Fig.15.2)haveexploredthepossibilityofconstruct-
ingthree-dimensionalbiomaterialscaffoldsinwhichnanofibersare
Figure 15.2. Thick layers of nanofibers deposited around bundles of
microfibers (courtesy of J. W. Freeman).
 
Search WWH ::




Custom Search