806891.fig.002a
(a)
806891.fig.002b
(b)
Figure 2: (a) Diagram of heparinized nanoparticles coated onto PLGA microsphere for stem cell delivery. (b) The SEM images of PLGA microspheres (upper (left) and bottom (right)) fabricated with heparin/poly(l-lysine) nanoparticles [37].