Biomedical Engineering Reference
In-Depth Information
17.9 SEM image of NS (A) and marked cell adhesiveness to NS in-vitro
(B). (A) NS microspheres approximately 100
μ
m in diameter (a). The NS
surface uniformly coated with nano-scale hydroxyapatite (nHA) crystals
was observed at different magnifications (low and high magnification in
(b) and (c), respectively). SEM image of NS cross-section indicating a
single layer of nHA particles on the NS surface (d). (B) Murine BMNCs
incubated with LA (a) or NS (b) and, (c) at 37
C for 8 h. Large numbers of
BMNCs adhered to NS ((b), and (c)) but not to LA (a). Scale bars: 100
8
m
μ
(A(-a), B(-a), B(-b); 5
m (A(-b)); 100 nm (A(-c), A(-d)) (Mima
et al., 2012). Copyright 2012, Plos ONE.
m (B(-c)); 1
μ
μ
success remains limited. Maintaining transplanted cells in place is expected
to augment cell-based therapeutic angiogenesis.
In 2012, nHA-coated PLLA microspheres, termed a nano-scaffold (NS),
were, for the first time, generated as a non-biological, biodegradable and
injectable cell scaffold (Mima et al., 2012). Mima et al. investigated the
effectiveness of the NS on cell-based therapeutic angiogenesis. The NS was
formed from microspheres approximately 100
m in diameter (Fig. 17.9A
(a)), the surfaces of which are coated with a monolayer of nHA particles of
50 nm diameter (Fig. 17.9A(b)-(d)). To assess the cell adhesiveness of NS,
SEM was performed after incubation of NS, with bare PLLA microspheres
(LA) as controls, with murine bone marrow mononuclear cells (BMNCs) at
37
μ
C for 8 h in-vitro. The number of cells adhering to NS was much greater
than that to LA (Fig. 17.9B(a) and (b)). High-magnification SEM images
showed active cell adhesion to the NS (Fig. 17.9B(c)).
BMNCs from enhanced green fluorescent protein (EGFP)-transgenic
mice and rhodamine B-containing PLLA microspheres (orange) as the
scaffold core or control microspheres were implanted into the ischemic hind
limbs of eight-week-old male (C57BL/6NCrSlc) mice to determine the co-
localization of implanted cells with injected microspheres (Fig. 17.10A). A
few implanted BMNCs were observed around the LA (Fig. 17.10A(a), while
markedly larger numbers of cells were seen with the NS (Fig. 17.10A(b)) in
8
