الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 91 |  |  |
| | | from | 91 | | |
Abstract
Diabetes is a multisystem disorder and complications of diabetes induce
physiological changes in tissues and cells that impair the normal healing process. The
pathophysiologic relationship between diabetes and impaired healing is complex. The
diabetic wounds get stuck in the inflammatory phasefeatured by continuing influx of
neutrophils that release cytotoxic enzymes.
Wounds that are difficult to heal represent a serious public health problem. The
lesions severely affect the quality of life of individuals due to decreased mobility and
substantial loss of productivity; they can also cause emotional damage and con-tribute to
increase the burden of public expenditures in healthcare.
Physical treatments such as therapeutic ultrasound,Laser and electrotherapy are cited
likewise in the literature as important adjuncts inwound management. These therapies
seem to be advantageous but they have limitations and do not always achieve satisfactory
results.
In recent years nanotechnology has been emerging asa rapidly growing field with
numerous applications in science and technology.
This work aimed to evaluate the role of antibacterial nanofibers by incorporating
silver nanoparticles into nanofibers using electrospinning as wound dressing on excisional
wound healing dynamics in diabetic mice in comparison with physical methods such as
therapeutic ultrasound and photostimulation using laser.
In the present study, we prepared different types of nanomaterials such as Ag
nanoparticles using chemical reduction process, CA nanofibers and Ag loaded CA
nanofibers using electrospinning process. The prepared Ag nanoparticles were
characterized using Transmission Electron Microscope (TEM) to determine the
morphology and the size of nanoparticles, X-ray Diffraction (XRD) pattern in order to
evaluate crystalline state and Particle Size Analyzer (PSA) determine the particle size
distribution curve of Ag nanoparticles.
The prepared CA and Ag loaded CA nanofibers were characterized in terms of
morphology by scanning and transmission electron microscope, Fourier-transform Infrared
spectroscopy (FTIR) to investigate functional groups. The antibacterial activity Ag loaded
CA nanofibers with (1, 3 and 5 %) AgNO3
using Disc Diffusion test and Growth kinetics
study was determined.
Accordingly Ag nanoparticles, CA and CA loaded with5% used for wound dressing
in excisional wound of diabetic mice in comparison with physical therapy as follow:
Group (I):Diabetic free served as control group (10 mice) injected with citrate buffer.
Group (II): Experimental group (60 mice) injected with Streptozotocin, this group will
be divided into the following subgroups:
IIa-Experimental group (10 mice), their open wounds left without treatment.
IIb-Experimental group (10 mice), their open wounds treated with Ag NPs only (50µL
every other day).
IIc-Experimental group (10 mice), their open wounds dressed with CA nanofiber only.
IId-Experimental group (10 mice), their open wounds dressed with CA nanofiber
contain AgNPs.
IIe- Experimental group (10 mice) treated with insulin combined with laser (650 nm,
150 mW) with a fluence of 5 J ⁄cm
2
5 minutes daily, for 10 days.
IIf- Experimental group (10 mice) treated with insulin combined with pulsed ultrasound
(0.5 W/cm
2
) 5 minutes daily, for10 days.
• The healing was noticed and assessed during the treatment period and the Healing
Factor Was determined.
• Histopatholgical Examination of mice skin during period of healing was done by
taking skin from each group in 4
th
, 10th, 15th days of treatment period.
• Taking after healing period and determine the mechanical properties of healed skin
The results of the present work are:
For Ag nanoparticles they were spherical in shape and there is a variation in particle
sizes ranging from 4.32nm to 7.27 nm with an average size 5.79 nm, from the XRD pattern
it is clear that silver nanoparticles were essentially crystalline in nature and from particle
size analyzer they were in a range of 29-41 nm. Thehighest fraction of Ag NP present in
the solution was of 33.3 nm.
Good quality nanofibers for CA and Ag loaded CA nanofibers with smooth surface
were obtained for CA and rough surface for Ag loaded CA nanofibers due to presence of
Ag nanoparticles. FTIR showed that there are no major difference between the two
samples in the major peak bands. However, it is also seen that the intensities of some peaks
increase, this can be attributed to the presence ofAg NPs. The antibacterial activity of CA
loaded with Ag Nanoparticles indicated high activity of CA loaded with 5% Ag
nanoparticles.
Wound dressing using nanofibers loaded with Ag NPs improve the skin wound
healing and the mechanical properties of the treated skin of the diabetic mice. Marked
improvement in wound strength and healing due to increase in formation of collagen fibers
and activity of the epithelial covering in mice receiving STZ and treated with insulin in
combination with dressing with nanofibers loaded with Ag NPs.
Healing factor of different group increases with increasing of the treatment time.
Healing factor of the diabetic mice treated with insulin dressed with nanofibers loaded with
Ag NPs shows a healing factor higher than that of the normal group.
By comparing results obtained from different treatment modalities, we found that all
therapeutic tools facilitate and accelerate diabetic wound healing, and improving scar
quality but with different degree, and the best method is to use nanomaterials (nanofibers
in conjugation with antimicrobial nanoparticles) which act as scaffold.
Conclusion
1- Nanotechnology is a very promising field that can be used in different application
and science like in medicine.
2- Nanomaterials especially metal nanoparticles and nanofibers are wonderful
materials that have unique properties than their original materials.
3- Abnormal wound healing that can occur during many pathological states like in
diabetic patients is a very dangerous and can lead to mortality in some cases, can be
treated using new therapies like using of nanotechnology.