Biomedical Engineering Reference
In-Depth Information
crystallites with orientations and sizes similar to those in natural bone
[131,132]. Nanoi brous scaf olds provide a superior environment for pro-
moting cell functions due to their nanometer pore sizes, e.g., biodegrad-
able and cytocompatible poly(DL-lactide-co-glycolide) (PLGA) nanoi bers
[133]. A self-assembling peptide, P4 (Ac-NH-LDLKLELKLDLKLELK-
CONH
2
), has 16 amino acids, 5 nm in size, with an alternating polar and
non-polar pattern. h e ability of the peptide to stabilize the hydrophobic
anticancer agent ellipticine was tested using two cancer cell lines including
SMMC7721 and EC9706 [134]. h e RADA16-I peptide hydrogel is a type
of nanoi ber scaf old extensively applied to regenerative medicine and tis-
sue repair in order to develop novel nanomedicine systems. Using phase
contrast microscopy, the appearance of the representative ovarian cancer
cells encapsulated in RADA16-I peptide hydrogel and suggested that pre-
cultured ovarian cancer cells had two-fold to i ve-fold higher anticancer
drug resistance than the conventional two-dimensional Petri dish culture.
So the 3D cell model on peptide nanoi ber scaf old is an optimal type of
cell pattern for anticancer drug screening and tumor biology [135]. h e
nanoi ber-cell-hydrogel composite enables replication of the cellular and
matrix architecture found in many natural tissues, of ering a novel protocol
for electrospun nanoi bers in regenerative medicine and bioengineering
[136]. Designed scaf olds comprised of natural and synthetic materials are
now widely used in the reconstruction of damaged tissues. Utilization of
absorbable and nonabsorbable synthetic and natural polymers with unique
characteristics can be an appropriate solution to repair damaged nerve tis-
sues. Polymeric nanoi brous scaf olds with properties similar to neural
structures can be more ef ective in the reconstruction process. Better cell
adhesion and migration, more guiding of axons, and structural features
such as porosity, provide a clearer role for nanoi bers in the restoration of
neural tissues [137].
Surface adhesion between nanoi bers and nanoparticles has attracted
attention for potential biomedical applications. Adhesion forces were
measured using a polystyrene (PS) nanoparticle attached to an atomic
force microscopy (AFM) tip/probe [138]. Gelain
et al.
have reported that
designer self-assembling peptide scaf olds facilitate with a slow and sus-
tained release of active cytokines that are extremely relevant to many areas
of regenerative medicine. h ey have suggested that not only do they pro-
vide evidence for long-term molecular release from self-assembling pep-
tide scaf olds, but also inspiration for a plethora of slow molecular release
strategies for clinical applications [139]. Kunduru
et al.
have demonstrated
the scaling down of the surface texturing from the micro- to the nanoscale,
which enhances the amplitude of the measured detected signal strength,
