INTRODUCTION
Fabrics hold an important place in human life, economic status of a country,
industrial and medical applications. Its usage in daily life is inevitable and
its harbouring ability of dirt and wastes is noticeable. The form a fabric get
yarned and weaved can accommodate more particles which act as substrates for
microbes to colonise on their surface. Antibacterial fabrics can be a good remedy
for retarding microbial growth on fabric surface. A prominent hygiene fabric
is essential, especially for the hospitalised immuno-suppressant patients. About
35% of the disease outbreak in hospitals is mainly due to the dissemination
of pathogenic microbes in air from various hospital used fabrics. Hospital environment
plays a vital role in determining the comfort and health of patients. The prevalence
of suspended particles in air can harbour microbes and pollutes the indoor environment.
The frequent bacterial species available in hospital indoor environment are
Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia
coli (Tambekar et al., 2007).
Fabrics with antimicrobial finish must be prominent for hygienic and medical
applications. Its major application is to prevent the bacterial growth on textiles.
To make a fabric with antimicrobial finish, three component features must be
considered. The antimicrobial substance to be coated on fabric surface, the
method used to impregnate the antimicrobial substance on the fabric surface
and the persisting ability of the antimicrobial action in the fabric after repeated
usage. Many substances have been used in view of its antimicrobial ability like,
antibiotics, formaldehyde, heavy metal ions, quarternary ammonium salts, phenol
and oxidizing agents, herbal formulations, natural biopolymers (Jakimiak
et al., 2006). Extracts from green tea leaves are used as eco-friendly
antimicrobial coating agents on cotton surfaces (Syamili
et al., 2012). Apart from antimicrobial finish, cotton textiles were
functionalized using anizidine a conducting polymer for antistatic applications
and as fireproof textile (Issaoui et al., 2011).
While using antimicrobial agents, their biocompatibility, persistence in fabric
surface against the abrasive forces during wearing and withstanding the leaching
effect of chemicals during washing have to be considered. A substance which
can resist the forces and establish its antimicrobial action effectively can
alone give a good antimicrobial finish to fabrics. A marine biopolymer extracted
from the shells of crustaceans called chitin shows stability to such adverse
effects. But exhibits less antimicrobial action. When deacetylated, the formed
chitosan from chitin can combat against microbes very effectively. Based on
the experiment of Batista et al. (2011), the
high molecular weight chitosan with less deacetylation percentage exhibits low
antimicrobial action against gram negative bacteria than the medium molecular
weight chitosan with high deacetylation percentage. Fungal mycelium is also
a good source of chitosan. When compared with other fungi, from Mucor
sp. KN03 mycelium higher amount of chitosan was derived (Nadarajah
et al., 2001).
Its biological properties includes bacteriostatic and fungistatic and used
in wound dressing materials to accelerate wound healing (Shanmugasundaram,
2012). Its mode of action on bacterial cells is by establishing cell surface
alterations. Chitosan can alter the cell wall permeability of bacterial cells
leading to poor metabolic function. This restricts bacterial growing and colonizing
ability (Je and Kim, 2006). Application of chitosan
in combination with various other antimicrobial agents increases their antimicrobial
nature. The extracted essential oils of thyme and clove were immobilized in
chitosan based edible films and analysed. They exhibit enhanced antimicrobial
effects than its individual forms (Hosseini et al.,
2008).
An annual production of chitin as second abundant biopolymer was estimated
as 1x1011 tons. Because of biodegradability, biocompatibility, hemostatic
and wound healing activity it is used widely in medical field. The drug release
profile of chitosan crosslinked with tripolyphosphate was analysed by Phromsopha
and Baimark (2010) using gentamicin sulphate antibiotic. A stable and sustained
release of the antibiotic was noted which could be advantageous than the burst
release of the antibiotic in patients intestine.
Even though chitosan is widely used, its poor or no water soluble property
is the major drawback. In its deacetylated form, chitosan is soluble in acids
and solvents. Further chemical modifications can make chitosan get dissolve
in water (Sugimoto et al., 1998). One such modified
chitosan called N,O-carboxymethyl chitosan (NOCC), in its amino and primary
hydroxyl sites of glucosamine units (backbone structure of chitosan) possess
carboxymethyl substituents. Carboxymethylated chitosan has good water solubility
and biocompatility as it fits with the neutral environment of human body (Dolatabadi-Farahani
et al., 2006). Similarly, Jideowno et al.
(2007) modified chitosan with acrylamide for the removal of heavy metal
ions from aqueous systems. Their results revealed the high sorption ability
of modified chitosan than normal.
Wound dressing material gets the prime importance in wound healing process
(Yang and Lin, 2004). The wound gauze with fine absorption
of wound exudates at the same time permit evaporation of moisture to certain
rate is needed (Liu et al., 2008). It should
not have close adherence with the tissues of wound area and creates pain, trauma
or additional tissue damage to the patients while removing (Mi
et al., 2002). An easily stripped wound dressing material must be
developed to reduce the pain suffered by patients when wound dressings are frequently
changed (Borkow and Gabbay, 2010).
Due to the haemostatic property, chitosan is used in wound management (Kumar,
2000). Chitosan can faster the wound healing process by decreasing the macrophage
prevalence in wounded site (Mi et al., 2001).
Alginate, a bio-fibre possesses gel forming ability by ion exchange process.
By exchanging the sodium ions of wound exudates with its calcium ions can form
gel. This gel forming nature of alginate helps to retain moisture. When a dressing
material coated with water soluble chitosan (NOCC) and alginate can accelerate
wound healing process (Knill et al., 2004).
In the present study, NOCC and calcium alginate were coated with the cotton
fibres of wound dressing material to analyse their wound healing effect. In
the previous studies chitosan has been coated as antibacterial finish in cotton
gauze but its water insoluble nature can not readily establish its antibacterial
effect in wounded sites. Hence as a good alternative, NOCC was applied as antimicrobial
coating against the used bacterial strains Staphylococcus aureus ATCC
6538 and Escherichia coli ATCC 10229. Sodium alginate can hold moisture
in the wound area essential for its healing. The water soluble NOCC can provide
immediate antimicrobial effect as it dissolves easily in body fluids prevalent
in the wounds to prevent bacterial colonisation.
MATERIALS AND METHODS
Materials: Chitosan with 85% degree of deacetylation and molecular weight
of 2X105 was purchased from Sigma Aldrich, USA. Sodium alginate was
provided by HiMedia, India. The other chemicals and reagents used were of analytical
grade. The standard bacterial cultures (Staphylococcus aureus ATCC 6538
and Escherichia coli ATCC 10229) were obtained from American Type Culture
Collection. The cotton yarns of 40s Ne was procured from Lakshmi
Mills Ltd., Coimbatore.
N,O-carboxymethyl chitosan (NOCC) synthesis: N,O-carboxymethyl chitosan
(NOCC) was synthesised following the method of Dolatabadi-Farahani
et al. (2006). Five grams of chitosan was suspended in 50 mL of isopropyl
alcohol and stirred in a magnetic stirrer at room temperature. NaOH solution
(10 N) of about 13 mL divided into 5 equal volumes was added to the slurry over
a period of 25 min. The alkaline slurry made was stirred for 30 min. Monochloroacetic
acid (30 g) divided into 5 equal portions was added with 1 min interval. The
temperature was raised to 60°C and continuously stirred for 3 h. The final
mixture was filtered and the synthesised NOCC was washed with methanol. After
washing, at 60°C the NOCC was oven dried.
Cotton gauze production: The cotton gauze was produced using the yarns
procured from spinning mills using gauze bandage loom. The loom has 300 picks
min-1 capacities and a width of 10-15 cm. Cotton yarns were spun
at Fashion Technology Department, Kumaruguru College of Technology and Coimbatore
to prepare the cotton gauze.
Properties of cotton gauze: The cotton gauze properties such as ends
per inch and picks per inch were measured using the counting glass. The area
density was measured using gsm cutter method as per ASTM D3775. Thickness and
stiffness of the fabric were measured as per ASTM D 1777-96 and ASTM D 6828
standard methods respectively (Shanmugasundaram, 2012).
Coating of cotton with NOCC and calcium alginate: NOCC (5.0 g) was dissolved
in double distilled water by stirring for 1 h at room temperature. A modified
method of Shanmugasundaram (2012) was used to prepare
polymer coated cotton gauze. In brief, calcium alginate (2.0 g) was added to
the NOCC solution and stirred for 10 min at room temperature. Cotton gauze to
be coated was dipped in the NOCC-calcium alginate solution and left overnight.
The coated cotton gauze was padded twice with the solution of same concentration
to a wet pick of 80%. The padded fabric was dried at 80°C for 5 min and
cured at 140°C for 3 min.
Calculating the add-on percentage: The polymer add-on percentage on
the gauze surface was calculated following the method of Shanmugasundaram
(2012) and was estimated using the following relationship:
where, W1 is the weight of polymer coated sample and W2,
the weight of un-coated sample.
SEM analysis: The coated cotton gauze were analysed for the presence
of polymer using scanning electron microscope. During sample preparation the
cotton gauze specimens to be analysed were mounted on aluminium stubs and using
Sputter Coater they were coated with gold and magnified in SEM.
Assay for antibacterial properties: The antibacterial effect of the
uncoated and coated cotton gauze was determined qualitatively by agar diffusion
plate test using EN ISO 20645:2004 method against Staphylococcus aureus
ATCC 6538 and Escherichia coli ATCC 10229. When effective antibacterial
activity was determined against the used bacterial pathogens, AATCC 100-2004
test method was used to analyse reduction in bacterial counts for quantitative
determination.
Qualitative antimicrobial determination by EN ISO 20645:2004 method proposed
by Erdem and Yurudu (2008) employs a two layered agar
plate. The lower layer has sterile culture medium (10±1 mL of Tryptic
Soy Agar-TSA) and the upper layer of agar (TSA precooled to 45°C) was inoculated
with individual test bacteria (1x108 cells). Test gauze specimens
(25±5 mm in diameter) were imprinted onto the inoculated TSA using sterile
forceps. Agar plates were incubated for 18-24 h at 37°C. Assessment of antibacterial
activity was determined by the extent of bacterial growth in the contact zone
between the agar and the gauze specimen.
Bacterial growth inhibition zones were calculated using the formula:
where, H is the zone of inhibition in mm, D is the total diameter of specimen
and inhibition zone in mm, d is the diameter of specimen in mm.
The antimicrobial activity was quantitatively evaluated against the standard
bacterial strain which gets effectively inhibited by EN ISO 20654:2004 method.
According to AATCC 100-2004 test method proposed by Pinho
et al. (2011), the cotton gauze samples both uncoated and coated
in a size of 4.25±0.1 cm in diameter were placed in separate 250 mL glass
jar with screw cap and inoculated with 1.0±0.1 mL of bacterial inoculum
(1x105 cells mL-1). After incubation over a contact period
of 24 h, 100 mL of sterilized distilled water was added into the jar and stirred
vigorously for 1 min. After serially diluting 1 mL of the solution, from every
dilution 1 mL of diluted solution was plated on nutrient agar and incubated
for 24 h at 37±2°C.
Wash fastness test (AATCC Test Method 124; Version-1996): AATCC test
method 124 was used for performing the wash fastness test. This test result
ensures the persistence of bioefficacy by bound polymers and herbal extract
to cotton gauze after certain number of washes. To evaluate the durability of
antibacterial effect and the persistence of coated polymers after washing, the
treated cotton gauzes were washed with AATCC Standard Reference Detergent WOB
(without bleaching agent). Both uncoated and coated samples were subjected to
3 cycles of consecutive laundering. At the end of the 1st and 3rd laundering
cycle, the samples were rinsed with warm water, air dried and tested for antibacterial
activity based on AATCC 100-2004 test method.
Bacterial reduction percentage: Colonies of bacteria recovered on the
agar plate from both uncoated and coated cotton gauze before wash (AATCC 100-2004
test method sample) and after wash (AATCC 124 test method) were counted and
the per cent reduction of bacteria (R) was calculated by the following equation:
where, A is the number of bacterial colonies from coated cotton gauze after
inoculation over a contact time of 18 h and B is the number of bacterial colonies
from uncoated cotton gauze after inoculation at 0 contact time.
Wound healing analysis: The wound healing function of the uncoated and
coated cotton gauze was analysed using an animal model. Female Albino rats weighing
approximately 150±10 g were left for 2 days at room conditions for acclimatization.
A standard pellet diet and water ad libitum was maintained throughout
the experiment. A minimum of three animals were used as one group for each specimen
(uncoated and coated) and for the control drug Teramycin ointment (Pfizer, USA)
(Tarun and Gobi, 2012). The study was permitted by
Institutional Animal Ethics Committee and was performed according to the international
rules relating to animal experiments and biodiversity right. All the animals
were anesthetized by intramuscular injection with 0.15 cc of Ketalar. The hairs
on the skin of animals were removed and disinfected using 70% ethanol. Circular
wound was created on the dorsal interscapular region of each animal by excising
the skin with a 10 mm biopsy punch (Diao et al.,
2008). The cotton gauze samples both coated and uncoated were placed on
the wound and the progressive changes in the wounded areas were monitored every
other day for 15 days using a camera (Nikon, Japan).
Statistical methods: In vitro results of cotton gauze with surface
coating formulation was compared statistically with uncoated sample to understand
the level of significance using SBSS (ver. 11.0) statistical software. The results
were presented as Mean±standard Deviation (SD). Chi Square test was used
to compare the mean values of polymer coated cotton gauze with uncoated sample
for the determination of antimicrobial activity. Statistical significance was
set at p<0.05. The wound healing percentage was analysed using One-way Analysis
of Variance (ANOVA). The values of p≤0.001 were considered statistically
significant.
RESULTS
Properties of cotton gauze fabric: The properties of cotton gauze fabric
prepared were listed in Table 1. It can be inferred that cotton
gauze prepared has similar specifications to that of the cotton gauze normally
used in medical practices.
Synthesis of NOCC: The direct alkylation method of chitosan to improve
water solubility was done using monochloroacetic acid as the alkylating agent.
The addition of carboxymethyl groups in its amino and primary hydroxyl sites
of glucosamine units can modify chitosan and lead to the synthesis of N,O-carboxymethyl
chitosan (Fig. 1). The synthesis of modified chitosan can
be confirmed by its water soluble ability.
Polymer add-on in cotton gauze fabric: Equation 1
was used to calculate the polymer add-on percentage in cotton gauze fabric.
The polymer add-on percentage of cotton gauze is 43.89. After polymer coating,
the final weight of cotton gauze gets increased than the initial weight. The
difference in the weight of cotton gauze was analysed in triplicate and the
mean value was expressed in Table 2. The presence of polymer
in the form of thin film of gel between the thread gaps in cotton gauze was
focused using stereo-zoom microscope (Fig. 2).
| Table 1: |
Properties of cotton gauze fabric |
 |
| The physical properties of cotton gauze weaved and analysed
according to the standards of ASTM standard methods |
| Table 2: |
Polymer add-on in cotton gauze |
 |
| An average (±std deviation) of duplicate specimen add-on%
were expressed |
|
| Fig. 1(a-b): |
Synthesis of N,O-carboxymethylated chitosan; (a) Chitosan
and (b) NOCC |
|
| Fig. 2(a-b): |
Polymer coating on cotton gauze; (a) Normal gauze and (b)
Polymer coated gauze |
SEM analysis: SEM analysis revealed that on the NOCC-alginate functionalized
cotton gauze, the presence of attached polymer particles were magnified and
shown in Fig. 3. The magnification from 100X to 5000X revealed
the density of the coated polymers on the surface of cotton threads. At lower
magnification, the cotton fibres were observed and in higher magnifications,
the polymers adhered on their surface were clearly evident.
Antibacterial property assay: The antibacterial activity analysed by
EN ISO 20645:2004 test method of the coated cotton gauze was expressed as zone
of inhibition diameter as an average (±standard deviation) of duplicate
determination using the Eq. 2. The results tabulated in Table
3 indicate the bioefficacy of the used polymer. The test exhibits good antibacterial
activity against S. aureus ATCC 6538 and limited effect on E. coli
ATCC 10229 (Fig. 4).
| Table 3: |
EN ISO 20645:2004 antibacterial assay method |
 |
| An average (±std deviation) of duplicate agar plate
values were expressed a Good effect, b Limited effect |
Even though coated cotton gauze was effective against S. aureus ATCC
6538 than E. coli ATCC 10229, the bacterial reduction percentage was
analysed for both the pathogens using AATCC 100-2004. The direct seeding of
microbial pathogens on the coated and uncoated cotton gauze enhance the microbial
colonisation on the fabric surfaces.
|
| Fig. 3(a-d): |
SEM images of normal and coated cotton gauze; (a) Normal
cotton gauze (X500), (b) Coated cotton gauze (X500), (c) Coated cotton gauze
(X2000) and (d) Coated cotton gauze (X5000) |
|
| Fig. 4(a-b): |
EN ISO 20645:2004 antimicrobial testing of coated cotton
gauze; (a) Zone of inhibition against S. aureus ATCC 6538 and (b)
No prominent zone of inhibition against E. coli ATCC 10299 |
Bacterial colonized cotton gauze when used can cause infection through wounds,
also spoil the fabric quality and make persistent odour. Using Eq.
3 the reduction percentage of S. aureus ATCC 6538 and E. coli
ATCC 10229 in uncoated sample was found to be 0 (Table 4),
whereas coated cotton gauze showed 92% and 80% bacterial reduction before wash,
respectively.
|
| Fig. 5(a-b): |
Wash fastness test of coated cotton gauze; (a) 10-4
dilution plates of E. coli and S. aureus and (b) 10-5
dilution plates of E. coli and S. aureus |
| Table 4: |
Bacterial reduction percentage by wash fastness test |
 |
| Bacterial reduction percentage before and after laundering
of cotton gauze indicates the persistence of antimicrobial ability of coated
cotton |
Wash fastness test (AATCC Test Method 124; Version-1996): The coated
and uncoated cotton gauze were washed for 1st and 3rd launderings to determine
whether the polymers bound to the fabric would be durable to normal launderings.
After washing, the cotton gauze were sterilized and then assayed for antibacterial
properties (Fig. 5). Following Eq. 3 the
reduction percentage of S. aureus (ATCC 6538) and E. coli (ATCC
10229) after the first wash was 85 and 78%, respectively. After the third wash
of fabric the calculated (Table 4) bacterial reduction percentage
showed more than 70% for both the pathogens.
Wound healing analysis: The albino rats were grouped into 3 comprising
3 individuals each. The wound healing process was analysed by measuring the
area of wound closure. The experiment was carried out in triplicate and the
mean value of the wound closure area was considered for statistical analysis.
| Table 5: |
Wound healing test in animal model |
 |
| The average mean values of triplicate sample result were used
for statistical analysis |
From Table 5, it is evident that wound healing action is
rapid using coated cotton gauze on wound. The usage of standard ointment is
the next best result obtained. The uncoated cotton gauze showed the poor result
comparatively (Fig. 6). The result indicates the wound healing
and antibacterial function of the biopolymers coated on the cotton gauze.
DISCUSSION
Chitosan is insoluble in water and hence the structure of chitosan was substituted
with carboxymethyl groups instead of amino and primary hydroxyl groups by treating
it with monochloroacetic acid to improve its water solubility.
|
| Fig. 6(a-c): |
Wound healing test in animal model; (a) Teramycin ointment,
(b) NOCC-alginate coated cotton gauze and (c) Uncoated cotton gauze |
The method used to prepare NOCC is direct alkylation method. The use of monohalocarboxylic
acid in the form of monochloroacetic acid is the key compound to form N-carboxyalkyl
and O-carboxyalkyl chitosan derivatives. The substitution of N- and O- alkyl
groups in amino and primary hydroxyl groups of chitosan occurs at high alkali
conditions attained by using NaOH along with alkylation by monochloroacetic
acid (Mourya et al., 2010). The specimen kept
under the scanning of electron beam offers the study of their surface morphology
under optimal conditions. The coating of polymers on the cotton surface was
observed along with the cotton fibres at higher magnifications (Gomes
et al., 2010). This result ensures the presence of polymers on the
sample. During the contact of these polymers by bacterial pathogens, the antibacterial
effect can retard the bacterial growth and its colonisation. The physical contact
of the coated polymers can induce wound healing by increasing the blood flow
and attracting platelets to the site of wound.
Calculating the polymer add-on percentage is important to understand the efficiency
of the technique used to coat the polymer on cotton gauze surface. The amount
of polymer added to the cotton gauze is responsible for the antimicrobial activity;
wound healing function and also the persistence of these activities for long
duration. For maintaining the appropriate moisture at the vicinity of wound
site, the presence of calcium alginate is essential. The dryness of the wound
between the changes of bandages gives more pain and trauma to the patients (Gupta
and Saxena, 2011). Alginate by contact with the wound exudates form gel
through ion exchange process. The calcium ions of the polymer and the sodium
ions in the wound exudate are the reasons for gel formation on the wound surface.
The formed gel absorbs moisture and maintains it which is essential for wound
healing. Alginate by its gel forming property makes the removal of wound dressing
without trauma and reduces the pain experienced by patient. Also it provides
a moist environment that leads to rapid granulation and reepithelialisation
of wounded tissues (Shanmugasundaram, 2012). For maintaining
the antimicrobial activity, NOCC coating in cotton gauze is essential.
According to EN ISO 20645:2004 standard test method’s evaluation, ≥1-0
mm inhibition zone and no growth under specimen were accepted as effective,
whereas 0 mm inhibition zone and slight growth were evaluated as limited effect
(Erdem and Yurudu, 2008). Agar diffusion test is a
preliminary test to detect the diffusive antimicrobial finish. Antibacterial
activity of tested gauze against Gram positive cocci was effective than Gram
negative rod. This resistance may be due to the complicated cell wall arrangement
of Gram negative bacteria. On the other hand, the Gram positive cocci have a
simple cell wall structure in which the cytoplasm membrane has a rigid peptidoglycan
layer composed of networks with plenty of pores, which allow foreign molecules
to enter the cell with ease. Since chitosan is comprised of membrane-active
microbiostatics can exhibit inhibitory effect of disrupting the cell membrane
permeability (Je and Kim, 2006).
The seeded bacterial inoculum on gauze surface coated with NOCC and alginate
can exhibit interference on their colonizing ability. The resistant bacterial
pathogen shows no changes in their morphology even when exposed to antimicrobial
agents. The bacterial morphology has a known importance in their analysis. The
antibiotics used against the bacterial pathogens can influence morphological
changes indicating its antibiotic resisting capability. When exposed to antibiotics,
bacteria shows significant morphological changes like variations in size and
shape. Many bacterial cells show a smaller size than usual and others are abnormally
larger. The change in their morphology directly indicates its antibiotic resisting
capability. Structural changes of bacterial cells are more evident when exposed
to bacteriostatic doses of antibiotics than under the effect of natural antimicrobial
agents like chitosan (Gomes et al., 2010).
The difference between the reduction percentage of uncoated and coated cotton
gauze were highly significant. This indicated that the chitosan bound to the
cotton fabric, exhibited its antibacterial activity and its property was not
affected even when mixed with calcium alginate.
The results of wash fastness test provided the evidence for the persistence
of antimicrobial activity of the polymer coated cotton gauze after washes. According
to the AATCC standards, less than 50% of bacterial reduction is considered to
be insignificant and more than 70% of bacterial reduction is acceptable (El-tahlawy
et al., 2005). The results of the analysed specimen showed >70%
of bacterial reduction. This ensures the resisting ability of the coated polymers
on cotton gauze against the abrasive force while laundering. The persistence
of the antimicrobial activity after 3rd wash shows the capability
of the polymer coating method used in this study.
The wound closure ability of the test specimens in animal models were compared
with the standard ointment every other day (Tarun and Gobi,
2012). The wound healing effect by polymer coated test specimen was observed
in accelerated form by checking the closure of wounded area. The test specimen
coated with calcium alginate along with chitosan helps to maintain moisture
than the uncoated test specimen (control). The presence of alginate polymer
leads to the formation of gel through ion exchange process. The gel formation
is due to exchange of ions between sodium in the wound exudate and the calcium
in polymer that influence moisture prevalence essential for wound healing (Shanmugasundaram,
2012). The bioactive property of chitosan affects macrophage prevalence
in the wound site for improved wound healing. The other properties like bacteriostatic
and fungistatic are particularly useful for wound treatment. The presence of
chitosan will provide antibacterial effect which helps the wounded cells to
regenerate without any microbial intervention. Hence, the presence of both sodium-calcium
ions along with alginate and chitosan accelerate wound healing effect. Due to
the presence of the moisture, the removal of cotton gauze in every dressing
was easy and patients experience no pain and trauma. Dried cotton gauze could
damage the new tissue layer formed while removing and this was avoided as it
was not sticking with the wound. Healing of wound in accelerated fashion because
of the antibacterial action of chitosan and moisture retaining property of alginate
are the reasons behind wound healing in animal model treated with coated cotton
gauze.
Wound healing in the used animal model exhibits a complex process involving
series of changes. The wound was associated with slight inflammation leading
to haemostasis and clot formation in the initial hours. In the first week of
wound healing, fibroplasia and neovascularization occurs. This leads to the
formation of granulation and re-epithelialization of tissues in the second week.
At the end of second week, new extracellular matrix and tissue remodelling takes
place for the wound to get heal (Diao et al., 2008).
CONCLUSION
Biopolymers chitosan and calcium alginate were used in this study for rapid
wound healing process. As chitosan is not a water soluble polymer, chemical
modification of carboxymethylation can yield N,O-carboxymethyl chitosan with
high water solubility. The cotton yarns of 40s Ne was used to weave
wound dressing cotton gauze. The pad-dry-cure method was used to coating the
biopolymers on the cotton gauze surface. The polymer add-on percentage showed
efficient coating of polymers by the cotton gauze. The functionalized cotton
gauze was analysed for its antibacterial activity against the bacterial pathogens
S. aureus (ATCC 6538) and E. coli (ATCC 10229). The qualitative
agar diffusion method and the quantitative AATCC 100-2004 methods were used
to analyse the antibacterial efficiency of the coated cotton gauze. The ability
of coated polymers to resist the abrasive force by laundering procedure was
analysed using wash fastness test. The presence of calcium alginate enhances
moisture retention in wound gauze which is essential for wound healing. This
was analysed using animal models with created wounds and wound healing was observed
in accelerated fashion on polymer coated cotton gauze. The alginate can form
gel by ion-exhange process with wound exudates and readily soluble NOCC can
avoid the microbial interference. These protective action leads to the rapid
closure and healing of wounds.
ACKNOWLEDGMENT
We are grateful to acknowledge Kumaruguru College of Technology for providing
the needed facilities. We also thank CMS Educational Trust for helping us to
conduct this research work and the Principal, Kunthavai Nachiar Govt. Arts College
for Women to finish the work.
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