Nanofibers and Nanosurfaces
115
endovascular prosthesis, loaded with antibody eluting with electrospun PLGA and
vancomycin nanofibers for reparation of mycotic aortic aneurysms [61]. A sustained
release of vancomycin antibody was observed until 30 days in vitro study. Similarly,
in in-vivo assessment, the protracting release of vancomycin in the aortic wall of
rabbits for eight weeks was observed. The use of drug-eluting nanofibers as a coating
on stents and prostheses can contribute to an increase in the success rate in the
treatment of aneurysms.
2.5 Guided Bone Regeneration Using Nanofibers
Guided bone regeneration (GBR) uses a membrane with specific properties such
as Osseo-conductivity, biocompatibility and mechanical properties as a barrier to
allow separation of the defected bone from soft tissues [24, 62]. Kouhi et al. synthesized a nanofibrous membrane composed of poly (hybutyrate-co-3-hydroxyvalerate)
(PHBV) -a degradable polyester, fibrogen and bredigite- a magnesium silicate
bioceramic. PHBV/FG/BR nanofibers demonstrated a minimum 25% increase ALP
activity of cells cultured on membrane compared to control PHBV and PHGV/FG
membranes [24]. To incorporate antibacterial effect in the membrane for GBR, wang
et al. developed metronidazole (MNA) and nano-hydroxyapatite (nHAs), based coreshell nanofibers. The outer layer of the shell was composed of polycaprolactone and
nHA, while the nanofiber core was gelatin and metronidazole. The results indicated that core-shell nanofibers were able to release MNA slower than only MNAloaded nanofibers, ie a slower MNA release profile was observed. In addition,
core-shell nanofibers also enhanced bone formation and could prevent the colonization of anaerobic bacteria [63]. Correspondingly, Liam et al., a composite bilayer
GBR membrane, the upper layer consisted of PLGA/gelatin nanofibers and silica
nanoparticles loaded with dexamethasone, while the bottom layer comprised of
PLGA nanofibers loaded with an antibiotic (doxycycline hyclate). Bone marrow stem
cells (BMSCs) cultured on dexamethasone loaded mesoporous silica nanoparticles in
PLGA/gelatin nanofibers (top layer) showed an upregulation of osteocalcin expression, highest ALP activity and mineralization than cells cultured on PLGA/gelatin
nanofibers, PLGA/gelatin loaded with silica nanoparticles and plastic tissue culture
plates. The bilayer membrane showed a 38.8% sustain release profile of dexamethasone loaded silica nanoparticles after 21 days and a total release of approximately
48% of antibiotic doxycycline hyclate over 21 days. Moreover, the bottom layer
PLGA/loaded with doxycycline hyclate formed an inhibition zone 3 times and four
times when tested with E.coli and S.aureus respectively indicating the effective broadspectrum antibacterial property [20]. However, despite possessing good biocompatibility, antibacterial activity and osteoconduction/induction properties, these studies
failed to assess the barrier properties of the GBR membrane. Tang et al. fabricated
a core-shell GBR membrane comprising of PLGA/Hydroxyapatite (HAp) as core
and collagen/amoxicillin as the shell. On culturing fibroblast on one side of the
115
endovascular prosthesis, loaded with antibody eluting with electrospun PLGA and
vancomycin nanofibers for reparation of mycotic aortic aneurysms [61]. A sustained
release of vancomycin antibody was observed until 30 days in vitro study. Similarly,
in in-vivo assessment, the protracting release of vancomycin in the aortic wall of
rabbits for eight weeks was observed. The use of drug-eluting nanofibers as a coating
on stents and prostheses can contribute to an increase in the success rate in the
treatment of aneurysms.
2.5 Guided Bone Regeneration Using Nanofibers
Guided bone regeneration (GBR) uses a membrane with specific properties such
as Osseo-conductivity, biocompatibility and mechanical properties as a barrier to
allow separation of the defected bone from soft tissues [24, 62]. Kouhi et al. synthesized a nanofibrous membrane composed of poly (hybutyrate-co-3-hydroxyvalerate)
(PHBV) -a degradable polyester, fibrogen and bredigite- a magnesium silicate
bioceramic. PHBV/FG/BR nanofibers demonstrated a minimum 25% increase ALP
activity of cells cultured on membrane compared to control PHBV and PHGV/FG
membranes [24]. To incorporate antibacterial effect in the membrane for GBR, wang
et al. developed metronidazole (MNA) and nano-hydroxyapatite (nHAs), based coreshell nanofibers. The outer layer of the shell was composed of polycaprolactone and
nHA, while the nanofiber core was gelatin and metronidazole. The results indicated that core-shell nanofibers were able to release MNA slower than only MNAloaded nanofibers, ie a slower MNA release profile was observed. In addition,
core-shell nanofibers also enhanced bone formation and could prevent the colonization of anaerobic bacteria [63]. Correspondingly, Liam et al., a composite bilayer
GBR membrane, the upper layer consisted of PLGA/gelatin nanofibers and silica
nanoparticles loaded with dexamethasone, while the bottom layer comprised of
PLGA nanofibers loaded with an antibiotic (doxycycline hyclate). Bone marrow stem
cells (BMSCs) cultured on dexamethasone loaded mesoporous silica nanoparticles in
PLGA/gelatin nanofibers (top layer) showed an upregulation of osteocalcin expression, highest ALP activity and mineralization than cells cultured on PLGA/gelatin
nanofibers, PLGA/gelatin loaded with silica nanoparticles and plastic tissue culture
plates. The bilayer membrane showed a 38.8% sustain release profile of dexamethasone loaded silica nanoparticles after 21 days and a total release of approximately
48% of antibiotic doxycycline hyclate over 21 days. Moreover, the bottom layer
PLGA/loaded with doxycycline hyclate formed an inhibition zone 3 times and four
times when tested with E.coli and S.aureus respectively indicating the effective broadspectrum antibacterial property [20]. However, despite possessing good biocompatibility, antibacterial activity and osteoconduction/induction properties, these studies
failed to assess the barrier properties of the GBR membrane. Tang et al. fabricated
a core-shell GBR membrane comprising of PLGA/Hydroxyapatite (HAp) as core
and collagen/amoxicillin as the shell. On culturing fibroblast on one side of the