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RESEARCH
Laser Photons
and Pharmacological Treatments in Wound Healing
Farouk A.H.
Al-Watban, MSc, PhD, and Bernard L. Andres, MT(AMT) Laser
Medicine Research Section, Biological and Medical Research
Department, King Faisal Specialist Hospital & Research Center,
Riyadh, Saudi Arabia.
The
exploitation of photobiology in medicine has been of great
interest to mankind. There is a growing interest in the use of
lasers for treatment purposes because of the photochemical
alterations induced in biomolecules by light energy. In this
paper we present our data on laser biostimulation, the
combination of pharmacological treatments SolcoserylTM (SS) and
PolygenTM (PG) with light therapy using in-vitro and in-vivo
models. In-vitro experiments indicate the ability of laser
photons and pharmacological agents SS or PG to augment or abate
the cloning efficiency of various cell lines. In-vivo studies
focused on the dosimetry of various laser wavelengths and the
use of wound healing drugs and 632.8nm laser in wound healing.
The application of pharmacological treatments combined with
laser therapy reveals the utility of light-drug treatment
combinations. Given the ever-increasing cost of medical care,
the burden incurred on patients, caregivers and society, this
line of research fulfills the increasing need to develop
treatment methods that enhance wound healing, especially in
situations involving resistance to healing.
The Biological Effects of Laser Therapy and Other
Physical Modalities on Connective Tissue Repair Processes
Chukuka S.
Enwemeka, P.T., Ph.D., FACSM, G. Kesava Reddy, Ph.D., Department
of Physical Therapy and Rehabilitation Sciences, University of
Kansas Medical Center, Kansas City, KS 66160-7601, USA
Connective
tissue injuries, such as tendon rupture and ligamentous strains,
are common. Unlike most soft tissues that require 7-10 days to
heal, primary healing of tendons and other dense connective
tissues take as much as 6 - 8 weeks during which they are
inevitably protected in immobilization casts to avoid re-injury.
Such long periods of immobilization impair functional
rehabilitation and predispose a multitude of complications that
could be minimized if healing is quickened and the duration of
cast immobilization reduced. In separate studies, we tested the
hypothesis that early function, ultrasound, 632.8 nm He-Ne
laser, and 904 nm Ga-As laser, when used singly or in
combination, promote healing of experimentally severed and
repaired rabbit Achilles tendons as evidenced by biochemical,
biomechanical, and morphological indices of healing. Our results
demonstrate that: (1) appropriate doses of each modality, i.e.,
early functional activities, ultrasound, He-Ne and Ga-As laser
therapy augment collagen synthesis, modulate maturation of newly
synthesized collagen, and overall, enhance the biomechanical
characteristics of the repaired tendons. (2) Combinations of
either of the two lasers with early function and either
ultrasound or electrical stimulation further promote collagen
synthesis when compared to functional activities alone. However,
the biomechanical effects measured in tendons receiving the
multi-therapy were similar, i.e., not better than the earlier
single modality trials. Although tissue repair processes in
humans may differ from that of rabbits, these findings suggest
that human cases of connective tissue injuries, e.g., Achilles
tendon rupture, may benefit from appropriate doses of He-Ne
laser, Ga-As laser, and other therapeutic modalities, when used
singly or in combination. Our recent meta-analysis of the laser
therapy literature further corroborate these findings.
Thermographic Study of Low Level Laser Therapy
for Acute-Phase Injury
Yoshimi Asagai,
M.D.1, Atsuhiro Imakiire, M.D.2, Toshio Ohshiro, M.D.3, 1.
Shinano Handicapped Children’s Hospital Shimosuwa, Nagano, Japan
2. Department of Orthopedic Surgery, Tokyo Medical University
Shinjuku, Tokyo, Japan 3. Japan Medical Laser Laboratory,
Shinanomachi, Tokyo, Japan
Acute-phase
injury is generally treated by localized cooling of the region,
and rarely by the active use of low level laser therapy (LLLT)
in Japan. Thermographic studies of acute-phase injury revealed
that circulatory disturbances at the site of trauma occurred due
to swelling and edema on the day following the injury, and that
skin temperature was high at the site of the trauma and low at
the periphery. Following LLLT, circulatory disturbances rapidly
improved, while temperature in the high temperature zone around
the site of trauma fell by 3 degrees on the average, but at the
periphery the low temperature rose by 3 degrees on the average
to nearly normal skin temperature. Clinically, swelling and
edema improved. LLLT was also useful in treating necrosis of the
skin in the wound area and in accelerating healing of surgical
wounds of paralytic feet, which are prone to delayed, wound
healing and also wounds due to spoke injury. LLLT is useful in
treating swelling and edema in acute-phase injury and in
accelerating healing of surgical wounds.
Advances in
Laser Therapy for Bone Repair
A. Barber 1,
JE. Luger 1, A. Karpf 1 , Kh. Salame 2 , B. Shlomi 3,G. Kogan 3,
M. Nissan 4, M. Alon 5, and S. Rochkind 2,6.
1Foot & Ankle
Unit, Departments of Orthopedic Surgery "B", Departments of
2Neurosurgery, 3Oral and Maxillofacial Surgery, and
5Rehabilitation, 6Division of Peripheral Nerve Reconstruction,
Tel Aviv Sourasky Medical Center, Tel Aviv University; 4Ben
Gurion University, Israel.
During the
last decade, it was discovered that low-power laser irradiation
has stimulatory effects on bone cell proliferation and gene
expression. The purposes of this review are to analyze the
effects of low- power laser irradiation on bone cells and bone
fracture repair, to examine what has been done so far, and to
explore the additional works needed in this area. The studies
reviewed show how laser therapy can be used to enhance bone
repair at cell and tissue levels. As noted by researchers, laser
properties, the combinations of wavelength and energy dose need
to be carefully chosen so as to yield bone stimulation. With
better study designs, the results will be more credible,
allowing for greater recognition of advances in bone repair
using laser therapy. Many studies on the effects of laser
therapy on bone healing and fracture repair have used
biochemical and histological methods. However, in order to
establish the effects of laser treatment on bone, additional
studies need to be performed using biomechanical tests, the
ultimate evidence of bone repair. Finally, future studies are
needed to demonstrate that the same bone stimulation effects
occurring in animals may also be seen in humans.
Attenuation and
Penetration of Visible 632.8nm and Invisible Infrared 904nm
Light In Soft Tissues
Chukuka S.
Enwemeka, Ph.D., FACSM Department of Physical Therapy &
Rehabilitation Sciences, University of Kansas Medical Center,
Kansas City, KS, and Department of Veterans Affairs Medical
Center, Kansas City, MO, U.S.A.
We studied
the depth of penetration and the magnitude of attenuation of
632.8nm and 904nm light in skin, muscle, tendon, and
cartilagenous tissues of live anaesthetized rabbits. Tissue
specimens were dissected, prepared, and their thicknesses
measured. Then, each wavelength of light was applied.
Simultaneously, a power meter was used to detect and measure the
amount of light transmitted through each tissue. All
measurements were made in the dark to minimize interference from
extraneous light sources. To determine the influence of pulse
rate on beam attenuation, the 632.8nm light was used at two
predetermined settings of the machine; continuous mode and 100
pulses per second (pps), at an on:off ratio of 1:1. Similarly,
the 904nm infra-red light was applied using two predetermined
machine settings: 292 pps and 2,336 pps. Multiple regression
analysis of the data obtained showed significant positive
correlations between tissue thickness and light attenuation (p <
.001). Student's t-tests revealed that beam attenuation was
significantly affected by wavelength. Collectively, our findings
warrant the conclusions that (1) The calf muscles of the New
Zealand white rabbit attenuates light in direct proportion to
its thickness. In this tissue, light attenuation is not
significantly affected by the overlying skin, a finding which
may be applicable to other muscles. (2) The depth of penetration
of a 632.8nm and 904nm light is not related to the average power
of the light source. The depth of penetration is the same
notwithstanding the average power of the light source. (3)
Compared to the 904nm wavelength, 632.8nm light is attenuated
more by muscle tissue, suggesting that is absorbed more readily
than the 904nm wavelength or conversely that the 904nm
wavelength penetrates more. Thus, wavelength plays a critical
role in the depth of penetration of light.
Biomodulation Effects on Cell Mitosis
After Laser Irradiation Using Different Wavelengths
R. Sroka, C.
Fuchs, M. Schaffer, U. Schrader-Reichardt, M. Busch, T. Pongratz,
R. Baumgartner LFL Laser – Research Laboratory – Clinic of
Urology and Clinic of Radiotherapy, University Munic, FRG
The
biostimulative effects on cell mitosis induced by laser light at
different wavelengths in cell cultures was investigated. Murine
skeletal fibroblasts (C2), normal urothelial cells (HCV29),
human squamous carcinoma cell line of the mouth (ZMK) and
urothelial carcinoma cells (J82) were irradiated with laser
light at ^=488, 630, 640 and 805+25 pm using a computer
controlled irradiation chamber. The irradiance was set to
10mW/cm(2) and 100mW/cm(2), while the irradiation varied between
2 and 201/cm(2). The mitotic was determined by single cell
counting after Orecein staining 24h post irradiation. The
mitotic rate showed a wavelength dependency with maxima at ^=635
and 805+nm for HCV29 and J82 cells. While the mitotic rate of C2
and J82 cells has the maximum value at about 41/cm(2), the
maximum was at about 81/cm(2). ZMK cells showed no increase. At
^=805+25pm C2 and ZMK cells showed slight decrease in the
mitotic rate after irradiation with 201/cm(2). An irradiation of
10mW/cm(2) was more effective than with 100m/Wcm(2). The
biostimulation of the mitotic rate of both normal and tumor
cells depends on the wavelength, irradiation and irradiance on
the cell line. The wavelength dependency in the ^=630 to 640nm
range could indicate a participation of endogenous porphyrins.
Because the results show stimulative as well as inhibiting
effects it should be considered to change the term
biostimulation into “biomodulation.” Information Application:
Supports laser induced biomodulation
Stimulation and Inhibition Effect of Lasers for
Wound Healing on Rats
Farouk AH Al-Watban,
Msc PHD and Xing Y Zhang, M.D. Laser Research, KFSH&RC, Kingdom
of Saudi Arabia
The
comparison of wound healing stimulation effects on rats using
HeCd, Argon, He Ne, and GaAIAs lasers (for 0.39 cm 2 wound size
and three times per week treatment schedule) were carried out.
The inhibition effect of low power Argon laser of wound healing
was also investigated. The results showed that the % of
acceleration in healing days were of 15.09, 22.93, 23.21 and
20.37 in 442nm, 514nm, 632nm, 786nm and 830nm at the incident
dose of 20 J/cm 2 , respectively. The results also suggested
that He Ne laser with 632nm was the most effective in promoting
wound healing in all wavelength used in this study. The
inhibitory effect of low power Argon laser showed the zero
bioactivation at the incident dose of 80 J/cm 2 and the
deceleration in healing days was –8.65% at the incident dose of
130 J/cm 2.
Computerized Morphometric Assessment of the
Effect of Low Level Laser Therapy on Bone Repair: an
Experimental Animal Study
Silva Júnior
AN, Pinheiro AL, Oliveira MG, Weismann R, Ramalho LM, Nicolau
RA. J Clin Laser Med Surg. 2002; 20: 83-87
The aim of
this study was to evaluate morphometrically the amount of newly
formed bone after GaAlAs laser irradiation of surgical wounds
created in the femur of rats. Low-level laser therapy (LLLT) has
been used in several medical specialties because of its
biomodulatory effects on different biological tissues. However,
LLLT is still controversial because of contradictory reports.
This is a direct result of the different methodologies used in
these works. In this study, 40 Wistar rats were divided into
four groups of 10 animals each: group A (12 sessions, 4.8 J/cm2
per session, observation time of 28 days); group C (three
sessions, 4.8 J/cm2 per session, observation time of 7 days).
Groups B and D acted as nonirradiated controls. The specimens
were routinely processed to wax and cut at 6-microm thickness
and stained with H&E. For computerized morphometry, Imagelab
software was used. RESULTS: Computerized morphometry showed a
significant difference between the areas of mineralized bone in
groups C and D (p = 0.017). There was no difference between
groups A and B (28 days; p = 0.383).
Therapeutic Low
Energy Laser Improves the Mechanical Strength of Repairing
Medial Collateral Ligament
Fung DT, Ng GY,
Leung MC, Tay DK. Lasers Surg Med. 2002; 31:91-96.
Twenty-four rats received
surgical transection to their right MCL and eight received sham
operation. After surgery, 16 received a single dose of gallium
aluminum arsenide laser to their transected MCL for 7.5 minutes
(n = 8) or 15 minutes (n = 8) and eight served as control with
placebo laser, while the sham group didn't receive any
treatment. The MCLs were biomechanically tested at either 3 or 6
weeks post-operation. The normalized ultimate tensile strength (UTS)
and stiffness of laser and sham groups were larger than control
(P < 0.001). The UTS of laser and sham groups were comparable.
Laser and sham groups had improved in stiffness from 3 to 6
weeks (P < 0.001). A single dose of low energy laser therapy
improves the UTS and stiffness of repairing MCL at 3 and 6 weeks
after injury.
