Civil Engineering Reference
In-Depth Information
of microbial cellulose/chitosan composite indicated that composite membranes had
balanced functionality of water absorption and dehydration that helped to maintain
the suitable moisture content for wound healing applications. h e tensile strength and
elongation at break for composite were slightly lower, while the Young's modulus was
higher. Cell culture studies demonstrated that microbial cellulose and microbial cellu-
lose/chitosan had no cytotoxicity. h e incorporation of chitosan into microbial cellulose
signii cantly increased the growth inhibition against
Escherichia coli
and
Staphylococcus
aureus
. h e ef ects of chitosan in the composite on skin wound healing were assessed
by animal models. h e histological examinations revealed that wounds treated with
microbial cellulose/chitosan composite epithelialized and regenerated faster than those
treated with microbial cellulose or Tegaderm, a commercial, well-known transparent
acrylic dressing. Properties of microbial cellulose membranes and how they relate to
the properties of ideal wound dressing materials are summerized in Table 16.1 [74].
Table 16.1
Properties of microbial cellulose membranes and how they relate to the properties
of ideal wound dressing materials [74].
Properties of ideal wound care dressing
Properties of microbial cellulose
maintain a moist environment at
the wound/dressing surface
high water-holding capacity (typical mem-
brane can hold up to 200 g of its dry mass in
water); high water vapor transmission rate
provide physical barrier against
bacterial infections
nanoporous structure does not allow any
external bacteria to penetrate into the
wound bed
highly absorbable
partially dehydrated membrane is able to
absorb l uid up to its original capacity.
Physical processing of the membrane (i.e.,
squeezing) can remove part of the initial
water and allow the membrane to be more
absorbable
sterile, easy to use, and inexpensive
membranes are easy to sterilize (by steam or
ç
-radiation) and package. h e estimated
cost of production of 1 cm
2
is $0.02
available in various shapes and sizes
ability to be molded
in situ
provide easy and close wound coverage,but
allow easy and painless removal
high elasticity and conformability
signii cantly reduce pain during treatment
the unique MC nanomorphology of never-
dried membrane promotes specii c interac-
tion with nerve endings
provide porosity for gaseous and l uid
exchange
highly porous material with pore sizes ranging
from several nanometers to micrometers
nontoxic, nonpyrogenic, and biocompatible
biocompatible, nonpyrogenic, nontoxic
provide high conformability and elasticity
high elasticity and conformability
provide mechanical stability
high mechanical strength (Young's modulus
value of several GPa)
