Biomedical Engineering Reference
In-Depth Information
was achieved through an active endocytosis mechanism. A large portion of DNA
delivered, however, was trapped in acidic endocytotic compartments, and subse-
quently was not expressed. These results suggest that with further modifi cation
to enhance their endosome escape, Arg-PEAs can be attractive candidates for
nonviral gene carriers owning to their high cellular uptake nature and reliable
cellular biocompatibility.
Katsarava
et al.
[18] used PEA and their blends for constructing various medical
biocomposites. One of them, registered as “PhagoBioDerm” in Republic of
Georgia and is produced as elastic fi lms, represents novel wound-dressing device
(artifi cial skin). Product consists of lytic bacteriophages, antibiotics, pain killer,
and proteolytic enzymes. PhagoBioDerm showed an excellent therapeutic effect
in the management of infected wounds and ulcers (of both trophic and diabetic
origin) [74] and in the complex treatment of infected local radiation injuries caused
by the exposure to
90
Sr [75] .
Recently, Katsarava
et al.
[76] have developed bactericidal wound dressing that
represents an alcohol solution of biodegradable
co -
PEA containing silver sulfadi-
azine and other antimicrobials. The preparation sprayed onto the wound forms a
thin, elastic, and transparent fi lm that accelerates healing of superfi cial wounds,
ulcers, and burns.
The functional biodegradable
co -
PEAs
8(L6)
0,75
K
0,25
with covalently attached
4-aminoTEMPO (Scheme 5.9) revealed high elastic properties and excellent adhe-
sion to stainless steel, and is being used as vascular stent coating. Currently the
polymer-coated stents are under clinical trials
1)
. The results of this study suggest
that the polymer is biocompatible and should not elicit an infl ammatory reaction.
Therefore, MediVas LLC (San Diego, CA) uses the biodegradable
co -
PEAs as bioac-
tive wound dressings [77], wound care polymer compositions [78], vaccine delivery
compositions [79], polymer particle delivery compositions [80], delivery of ophthal-
mologic agents to the exterior or interior of the eye [81], therapeutic polymers [82],
and so forth.
5.2.6
AABBPs versus Biodegradable Polyesters
Here in brief are listed some advantageous properties of AABBPs over aliphatic
PEs like polyglycolic and poly(lactic acids), their copolymers, poly(caprolactone),
and so forth:
•
polycondensation synthesis without using any toxic catalyst;
•
higher hydrophilicity and, hence, better compatibility with tissues;
•
longer shelf - life;
•
a wide range of desirable mechanical properties at lower molecular weights;
1)
Medivas' polymer technology was licensed to DSM Biomedical, http://www.dsm.com/en_US/
html/dbm/homepage.htm.
