Functional Mesoporous Silica Nanoparticles with a Core-Shell Structure for Controllable Drug Delivery - Advanced Bioactive Inorganic Materials for Bone Regeneration and Drug Delivery - page 63

(a) (b)

Fluorescein loading
APTES modication

Fluorescein

Poly (L-Lysine)
(PLL)

CpG ODN

α-Chymotrypsin

100 nm

Positive
control

1 2 3 4 5

100

(c) (d) Fluorescein release without enzyme

CpG ODN release without enzyme
Fluorescein release with enzyme
CpG ODN release with enzyme

80

60

40

20

0

0 5 10

Time (hour)

15 20 25

FIGURE 3.8
(a) Schematic procedure for preparation of the fluorescein and CpG ODN-loaded HMS/PLL
particles and enzyme-triggered release. (b) TEM images of HMS particles. (c) Gel electro-
phoresis of the MFHMS suspension and the MFHMS/(CpG/PLL) n suspensions before and
after the treatment with an α-chymotrypsin solution. (d) Release profiles of fluorescein and
CpG ODN from the MFHMS/(CpG/PLL) 3 particles in 0.1 M acetic acid buffer in the absence
and in the presence of α-chymotrypsin (10 μg/mL). (Reprinted with permission from Zhu
Y., Meng W., Gao H., et al., J. Phys. Chem. C. 115: 13630-13636, Copyright 2011, American
Chemical Society.)

gene, and positively charged PLL polymer alternatively to obtain the fluo-
rescein and CpG ODN-loaded HMS/PLL particles (MFHMS/(CpG/PLL)n;
n is the assembled number). Finally, fluorescein and CpG ODN can simul-
taneously release from the MFHMS/(CpG/PLL)n particles stimulated by
α-chymotrypsin that can induce PLL polymer degradation. This co-delivery
system can give an enzyme-triggered controlled release of drug and gene
simultaneously, and the release rates of drug and gene from the HMS/PLL
particles can also be controlled by changing the enzyme concentration.
Therefore, this system has the advantages of both enzyme-triggered con-
trolled release and co-delivery of drug and gene, and would have potential
and promising applications in the field of biomedicine and cancer therapy.