Biomedical Engineering Reference
In-Depth Information
O
O
O
O
O
NH
CH
2
C
O
O
C
CH
2
NH
C
(CH
2
)
2
C
n
Scheme 5.7
Water-soluble PEAs on the basis of 1,4-anhydroerythritol, glycine, and succinic
acid.
HN
O
O
O
O
O
O
O
NH
(CH
2
)
8
(CH
2
)
4
O
NH
NH
(CH
2
)
8
O
1
1.5
OCH
2
Ph
O
NH
O
O
O
(CH
2
)
6
O
(CH
2
)
8
HN
O
1.5
Scheme 5.8
Biodegradable polymeric drug composed of 17
β
- estradiol, 1,6 - hexanediol,
l
- leucine,
l
-lysine benzyl ester, and sebacic acid.
These PEAs are suitable for constructing devices with sustained/controlled
release in which a drug is attached to the macromolecules via hydrophobic forces.
Hydroxyl - containing and water - soluble PEAs
. PEAs containing free OH
groups were obtained by Gomurashvili
et al.
[60] by AP of TAADs composed of
unsubstituted
- AA glycine and glycerol with di-
p
- nitrophenyl esters of succinic,
glutaric, adipic, and diglycolic acids. Depending on the synthetic strategy used,
three types of hydroxyl-containing polymers were synthesized: PEAs with pending
primary hydroxyls, with pending secondary hydroxyls, or a copolymer containing
both primary and secondary glycerol hydroxyls (not shown here). PEAs composed
of short aliphatic diacids such as succinic, glutaric, and diglycolic acids are water
soluble.
Water-soluble PEAs, having the structure given in Scheme 5.7, were also
obtained by AP of TAAD composed of 1,4-anhydroerythritol and glycine with di-
p
- nitrophenyl succinate [60] .
Polymeric drugs
. The strategy of the synthesis of AABBPs allows constructing
biodegradable polymeric drugs. For example, therapeutic copolymers composed
of sebacic acid, L - leucine, 1,6 - hexanediol, 17
α
- estradiol, and L - lysine benzyl ester
(
M
w
up to 82,000 Da) was obtained by Gomurashvili
et al.
[61] via AP of di-
p
- nitro-
phenyl sebacate with three comonomers - two TAADs composed of l - leucine/1,6 -
hexanediol and l - leucine/17
β
β
- estradiol, and di -
p
-toluensulfonic acid salt of l - lysine
benzyl ester, Scheme 5.8 .
