1. Preparation of magnetic β - glucan microspheres by microemulsion method for targeting drug delivery system
Jun Hee Cho 1*, Sang Gil Ko1, Yangkyu Ahn1, Ki-Chang Song2, Eun Jung Choi3
1Department of Nanochemistry & Biochemistry, Konyang University
Nonsan, Chungnam, Korea
2Department of Chemical Engineering, Konyang University
3Department of Opthalmic Optics, Konyang University
Daejeon , Korea

2. Abstract
Magnetic polymer particles can be used for several clinical applications. They were recently introduced as a suitable material for drug targeting, hyperthermia, embolotherapy and magnetic resonance imaging agent. We have synthesized uniform nanometer sized magnetite particles using chemical coprecipitation technique through a sonochemical method with surfactant such as oleic acid. The average size of the magnetite particles can be controlled by the ratio R = [H2O]/[surfactant] in the range of 2 to 8nm. The size of the magnetite nanoparticles prepared by this method show narrow distribution. Powder X-ray diffraction and electronic diffraction measurements show the spinel structure for the magnetite nanoparticles. Morphology of magnetite nanoparticlewas investigated using atomic force microscope(AFM). Magnetic β-glucan microspheres were prepared by a water-in-oil suspension-crosslinking technique. Magnetite nanoparticles were dispersed in a β-glucan solution in alkali solution. The dispersion was added to iso-octane containing Span 80 as a surfactant with stirring. An anticancer drug, 5-Fluorouracil(5-Fu), was immobilized into the magnetic β-glucan microspheres by a swelling method. The magnetic β-glucan microspheres were crosslinked with glutaraldehyde. The surface, and the morphology of the magnetic β-glucan microsphere particles were characterized using optical microscope and scanning electron microscope(SEM). Magnetic hysteresis measurement were performed using a superconducting quantum interference device (SQUID) magnetometer at room temperature to investigate the magnetic properties of the magnetic β-glucan microspheres. The amount of 5-Fluorouracil(5-Fu) released into the aqueous media was measured by UV spectroscopy at 265 nm.
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

3. Requirements of magnetite nanoparticles for medical application
Objective of this study
Synthesis of uniform magnetite nanoparticles using sonochemical method
Control of the size of the magnetite particles
Preparation of magnetic β-glucan microspheres capable of targeted drug
to minimize burst
Control of drug-release rate by concentration of crosslingking agent
• Superparamagnetic
• Size < 20 nm
• Narrow size distribution
• Spherical Shape
• Low toxicity
uniform
magnetite
nanoparticles
Requirements of magnetite nanoparticles for medical application
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

4. Sonochemistry ? Acoustic Cavitation
- the formation, growth, and implosive collapse of bubbles in a liquid
Cavitational Collapse
- intense local heating(~5000 K)
- high pressures(~1000 atm)
- enormous heating and cooling rates(109 K/sec)
Advantages
- have a narrow size distribution & control of particle size
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

5. Non toxic, Biocompatible,
Structures and properties of β-glucan
β-glucan
Extraction is extracted from mushroom
Molecular form : (-C6H10O5-)n
Dissolve in alkali solution
Gelate in acid solution
Reducing serum cholesterol levels
Anticancer effect
Diet food
Non toxic, Biocompatible,
Non carcinogenic
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

6. Targeting drug delivery system ?
Drug loaded magnetic
biopolymer microspheres
Magnet
Blood vessel
Biopolymer
Magnetite
nanoparticles
Drug
Magnetic drug carrier
Time
Drug Level
Maximum Designed Level
Minimum Effective Level
Toxic Level
Dose
Controlled Release DDS
ODDS
Conventional Administration
Discontinuous drug-release
Side effect
Frequent dose
Biocompatible
Controlled Release
Drug delivery system (DDS)
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

7. Synthesis of magnetite nanoparticles
FeCl2·4H2O
(0.15M, 30ml)
add oleic acid
(sodium form)
heating
to 70℃ +
sieve
washing
by centrifuge
metal chloride mixture
aqueous solution
FeCl3·6H2O
(0.3M, 30ml)
optimum conditions:
 add Precipitator ( TMAOH, 72mmol )
 irradiation power : 250 W
 irradiation time : 30min
 irradiation temperature : keeping 70 ~ 80℃
uniform magnetite
nanoparticles
Biomedical application
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

8. Size distribution of magnetite nanoparticles
(1)
(3)
(4)
(2)
R=[water] /
[surfactant]
Particles size
(nm)
Distribution
(%)
S.Dev
(nm/%)
Magnetite
nano particles
(1) 95
2.2
100.0
0.3/13.3
(2) 104
4.1
99.5
0.4/11.2
(3) 114
5.6
97.9
0.5/9.8
(4) 133
9.0
94.1
0.8/10.8
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

9. Characterizations of magnetite nanoparticles
AFM images
R=[water]/[sulfactant]=95
Mean size = 3.5 nm
R=[water]/[sulfactant]=133
Mean size = 6.4 nm
220
311
400
422
511
440
X-ray diffraction pattern
-- R=[water]/[sulfactant]=133
Mean size= 9.0 nm
-- R=[water]/[sulfactant]=95
Mean size= 4.1 nm
Magnetic hysteresis curve
• Superparamagnetic
• Size < 20 nm
• Spherical Shape
Biomedical
application
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

10. Preparation of magnetic β-glucan microspheres
magnetite colloid &
β-glucan mixture
add EtOH
vacuum dry
washing
iso-octane
Span 80
at 40℃
(((
))) H S
magnetic β-glucan
microspheres
optimum conditions:
 stirring time : 90 min
 stirring temperature : room temperature
β-glucan
Magnetite
nanoparticles
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

11. Preparation of drug loaded magnetic β-glucan microspheres
Model drug
5-Fluorouracil(5-Fu)
Crosslinking agent
Glutaraldehyde
Magnetite
nanoparticles ` `
(((
))) `
add EtOH
D.I water
freeze dry
β-glucan
30min
room
temperature
washing
(((
))) H S
Drug
Sonicator (water bath type)
In vitro
release studies
optimum conditions:
 stirring time : 90 min
 stirring temperature : room temperature
measurement : using UV spectrophotometer
 absorption of UV spectrophotometer : 265nm
 incubate temperature : keeping 37.0±0.5℃ `
Water bath
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

12. Optical microscope images of magnetic β-glucan microspheres
(1)
(2)
Span 80 (ml)
Iso-octane(ml)
5% (w/v)
β-glucan(ml)
Glutaraldehyde (mol)
Size(㎛)
Microsphere 1 6
140 20
0.015
31.58
Microsphere 2 10
25.53
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

13. SEM images of magnetic β-glucan microspheres
Crosslinked with
glutaraldehyde
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

14. Characterization of drug release
(1)
(2)
(3)
Non crosslinking
mol glutaraldehyde
mol glutaraldehyde
Loading efficiency :
( Calculated drug concentration )
( Theoretical drug concentration )
×100
Crosslinking
agent (mol)
Loading efficiency (%)
Released (%)
Magnetic
β-glucan microspheres
(1) non crosslinking
91.0
96.2
(2)
25.9
75.5
(3)
24.9
65.8
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY

15. Conclusion
(1) Magnetite nanoparticles were synthesized by sonochemical method
(2) The particle size of magnetite and microsphere can be controlled by
concentration of surfactant
(3) The synthesized particles show narrow size distribution under S.D 10%
(4) Magnetic β-glucan microspheres were prepared by a water-in-oil
suspension-crosslinking technique
(5) The in vitro release profile revealed the ability of microspheres to
prolong the drug release for more than 24 hrs
(6) The water soluble magnetic β-glucan microspheres showed more
sustained drug release profiles by increasing crosslinking agent.
DEPARTMENT OF CHEMISTRY, GRADUATE SCHOOL, KONYANG UNIVERSITY