Biomedical Engineering Reference
In-Depth Information
These results support the notion that polymer has a high potential for cardiovas-
cular applications [71] .
Recently Yamanouchi
et al.
[34] reported that the arginine-based PEAs showed
good cell compatibility over a wide range of dosages and had minimal adverse
effects on the cell morphology, viability, and apoptosis. Very recently, Memanish-
vili
et al.
[35] showed that arginine-based PEEAs, PEEURs, and PEEUs, having
PEG-type polymeric backbones, possess higher cell compatibility than the said
arginine - based PEAs.
The above -mentioned biological studies of several biodegradable AABBPs indi-
cate that this family of biodegradable polymers is biocompatible. However, these
studies are rather sporadic and comprise mostly the assessment of biocompatibil-
ity. So far there is no systematic study of biocompatibility and/or tissue regenera-
tion potential. In particular, there is no relevant data about tissue regeneration
mechanisms and the infl uence of factors like chemical composition and biodeg-
radation rate that determines discharging of degradation products into surround-
ing environment that can activate macrophages to produce cell growth factors,
mediators, and so forth, for accelerated wound healing [72, 73]. Therefore, for wide
practical applications of this very promising family of biodegradable polymers, it
is indispensable to carry out a comprehensive study of the interaction of AABBPs
of various chemical compositions with living organism to assess their biocompat-
ibility (including immune response), and tissue regeneration capability.
5.2.5
Some Applications of AABBPs
Selected representatives of PEAs were used for constructing biodegradable hydro-
gels, nanoformulations, drug-eluting devises and coatings, and so forth.
Chu and Guo used the UPEAs for obtaining hybrid hydrogels through photo-
chemical conjugation with either PEG diacrylate [30] or polysaccharides containing
unsaturated double bonds (e.g., methacryloyl dextrane) [29]. The biodegradable
hybrid hydrogels are promising for many biomedical and pharmaceutical applica-
tions, such as drug delivery systems and tissue engineering and so forth.
Legashvili
et al.
[31] used brush - like
co-
PEAs (Figure 5.11) to obtain molecular
complexes with PEGs that are promising as nanocarriers of drugs.
Yamanouchi
et al.
[34] evaluated complexation of a novel family of synthetic
biodegradable l - arginine-based PEAs (Figure 5.9) with DNA, for their capability
to transfect rat vascular smooth muscle cells, a major cell type participating in
vascular diseases. Arg-PEAs showed high binding capacity toward plasmid DNA.
The binding activity was inversely correlated to the number of methylene groups
in the diol segment of Arg-PEAs. All Arg-PEAs transfected smooth muscle cells
with an effi ciency that was comparable to the commercial transfection reagent
Superfect. However, unlike Superfect, Arg-PEAs, after a wide range of dosages,
had minimal adverse effects on cell morphology, viability, and apoptosis. The
authors demonstrated that Arg-PEAs were able to deliver DNA into nearly 100%
of cells under optimal polymer-to-DNA weight ratios, and the high level of delivery
