Transcript Photocured Films of Hyaluronic Acid Functionalized with

Photocured Films of Hyaluronic Acid
Functionalized with Cyclodextrin
Scott A. Zawko1, Shalu Suri2, Prinon Hossain2,
Quan Truong2, Christine E. Schmidt1,2
1Department
of Chemical Engineering
2Department
of Biomedical Engineering
The University of Texas at Austin, Austin, TX
Goal:
Drug
Hydrogel material that binds
drug molecules
Gel
Uptake
Release
Matrix: Hyaluronic Acid
Functionalities: Cyclodextrin
Composite Hydrogel Material
Hyaluronic Acid
Cyclodextrin
High molecular weight
Host-Guest Inclusion
Complexes
High water content
Increase solubilization
High porosity
Decrease crystallization
Biocompatible
Increase stability
Biodegradable
OH
O
OH
HOOC
O
HO
O HO
O
OH
OH
HO
O
O
O
HO
OH
O
HO
OH
OHO
OH
O
HO
O
OH
O
OH
NHCOCH3
n
MW = 5x105 – 2x106
O
OH
HO
OH
O
HO
HO
O
O
OHO
O
OH HO
O
HO
O
OH
7
HO
OH
Cyclodextrin’s Structure
OH
O
OH
HO
HO
O
O
HO
OH
O
HO
OH
OHO
O
HO
O
OH
Hydrophobic
Interior
O
OH
OH
HO
OH
O
HO
HO
O
OHO
O
OH HO
O
HO
O
OH
b-cyclodextrin (n=7)
HO
a-cyclodextrin (n=6)
Adamantane
I.D. ~ 6 Å
Hydrophilic
Exterior
Ka ~ 105 M-1
+
OH
Cyclodextrin’s Structure
8
7
6
Hydrocortisone
Solubility (mM)
5
4
3
2
1
0
0
5
10
15
b-Cyclodextrin (mM)
O
O
C
HO
+
CH3
CH3
CH2OH
HO
CH3
Ka ~ 103 M-1
O
O
Hydrocortisone
C
CH3
CH2OH
Photocrosslinked Hydrogels
+
Photoinitiator
UV Light
Methacryloyl
Hyaluronic Acid
Methacryloyl
Cyclodextrin
O
OH
HOOC
O
O
+
O
HO
O HO
O
OH
Leach, J.B. et al. (2003) Biotechnol Bioeng
O
NHCOCH3
GMHA
Triethylamine
Methacryloyl Hyaluronic Acid (GMHA)
Molar Excess
Degree of
Substitution
6x
10x
20x
0.05
0.07
0.11
O
OH
HOOC
O
O
+
O
HO
O HO
O
OH
Leach, J.B. et al. (2003) Biotechnol Bioeng
O
NHCOCH3
GMHA
Triethylamine
Methacryloyl Hyaluronic Acid (GMHA)
Molar Excess
Degree of
Substitution
Molar Excess
Water / Acetone
Degree of
Substitution
6x
10x
20x
0.05
0.07
0.11
20x
20x
20x
100 / 0
70 / 30
50 / 50
0.11
0.23
0.32
O
OH
HOOC
O
O
+
O
HO
O HO
O
OH
Leach, J.B. et al. (2003) Biotechnol Bioeng
O
NHCOCH3
GMHA
Triethylamine
Methacryloyl Cyclodextrin
Methacrylic Anhydride
OH
O
OR
O
NaOH, pH 8
O
O
n
HO
n
OH
R = H or
RO
O
C
OR
n = 6, a-cyclodextrin
n = 7, b-cyclodextrin
O
Possible steric
hindrance
HO
C
CH3
CH2OH
O
CH3
O
O
O
O
O
O
Methacryloyl Cyclodextrin
3
MAbCD
2
4
DS = 3.2
5
1
6
No unpolymerizable CD
Low average DS
3
2
MAaCD
4
5
1
DS = 3.6
Comparable DS
Quantitation of MAbCD-Hydrocortisone Binding
Hydrocortisone
[Hydrocortisone] (mM)
CD (mM):
0
1
3
5
12
MAbCD: 1400 M-1
10
8
slope
Ka 
(1 - slope)[L]0
6
4
bCD: 5380 M-1
2
0
0
5
10
[Cyclodextrin] (mM)
15
Hyaluronic Acid Gels
Hyaluronic Acid Films
Swelling of Hyaluronic Acid –
Cyclodextrin Hydrogels
+
I2959, UV Light
Cyclodextrin
Hyaluronic Acid
CD / HA Hydrogel
0.5% w/v
2% w/v
20% CD / 80% HA
1.0% w/v
33% CD / 67% HA
1.5% w/v
43% CD / 57% HA
50
bCD / HA
aCD / HA
40
Swelling
Ratio
(PBS)
30
20
10
0
HA
20
33
43
Cyclodextrin (%w/w)
Hyaluronic AcidCyclodextrin Hydrogels:
Hydrocortisone Uptake
and Release
Hydrocortisone
Uptake
Gel
Release
70
43% bCD
60
Hydrocortisone
Release (mg)
50
33% bCD
40
20% bCD
43% aCD
30
20
20% aCD
10
HA
0
0
10
20
30
Time (h)
40
Hyaluronic AcidCyclodextrin Hydrogels:
Hydrocortisone Uptake
and Release
Hydrocortisone
Uptake
Gel
Release
0.25
1 HC : 8 MAbCD
0.20
Hydrocortisone
Release (mmol)
0.15
1 HC : 21 MAaCD
0.10
0.05
0.00
0.0
0.2
0.4
0.6
0.8
1.0
Cyclodextrin (mmol)
1.2
1.4
Hyaluronic AcidCyclodextrin Hydrogels:
Hydrocortisone Uptake
and Release
Pre-incubation with
Adamantane Carboxylic Acid
80
COO-
70
Hydrocortisone
Release (mmol)
60
50
40
30
20
10
0
HA
43% bCD
43% bCD
Adamantane
Hyaluronic Acid Gels
Hyaluronic Acid Films
Methacryloyl Hyaluronic Acid Films
UV
Air Dry
GMHA +
Photoinitiator
Water / Acetone
100 / 0
70 / 30
50 / 50
Degree of
Substitution
Films
0.11
0.23
0.32
N
Y
Y
Optimization of Photoinitiator
80
6
70
5
1 min UV
60
4
50
Swelling Ratio
3
(PBS)
40
30
2
20
1
10
0
0
0.0
2.5
5.0
7.5
10.0
% Photoinitiator (w/w)
% Linear
Expansion
Optimization of UV Exposure
3.5
45
40
5% PI
3.0
35
2.5
30
Swelling Ratio 2.0
(PBS)
25
20
1.5
15
1.0
10
0.5
5
0.0
0
0
1
2
3
4
UV Exposure (min)
5
6
% Linear
Expansion
Autoclave Sterilization of HA Films
4.0
30 minutes at 121 C and 15 psi
3.5
60
50
3.0
40
Swelling Ratio 2.5
(PBS)
30
2.0
1.5
20
1.0
10
0.5
0
0.0
None
Fast
Sterilization
Slow
% Linear
Expansion
Resistance to Cell Adhesion
Human Dermal Fibroblasts
500 mm
HA Film
TCPS
Methacryloyl Hyaluronic Acid Films
Properties
Transparent
Free Standing
Highly Dense
300 nm
Low Swelling
Biodegradable
Non-cell adhesive
Patternable
Applications
Post-surgical adhesion barriers
Coatings
100 mm
Goal:
Drug
Hydrogel material that binds
drug molecules
Gel
Uptake
Release
Matrix: Hyaluronic Acid
Functionalities: Cyclodextrin
Acknowledgements
Funding Agencies
NSF BES – 021744
NSF BES – 0500969
http://www.bme.utexas.edu/faculty/schmidt