A collaborative study with Harvard Medical School
Technology
Protonated Bioadhesive Technology (PBT®)
Axio Biosolutions employs the proprietary Protonated Bioadhesive Polymer technology (PBT®) to make its biopolymer-based Haemostats, drug delivery systems and scaffolds with tailorable bioadhesive properties. These preparations are unique in a sense that they adhere to the tissues when needed and easily detach when their job is done.
Axiostat’s mechanism of action is based on the Protonated Bioadhevie Technology(PBT®) which includes 4 major aspects including charge-based interaction with blood components, platelet activation via Toll-like receptors (TLR), Clotting cascade activation and fibrin plug formation. As anticoagulant drugs do not interact with TLR receptors, Axiostat can control massive bleeding even in patients under anticoagulation therapy.
The essence of PBT technology lies in maximizing the bioadhesive properties of native chitosan without chemical modifications in its backbone. Structurally, chitosan is a natural polysaccharide composed of monomers of glucosamine and N-acetyl glucosamine. Chitosan gets its cationic (+ve) charge through the protonation of primary amines ( NH 2 ) groups present in its glucosamine subunits. However, this protonation is pH-dependent, at a pH above 6.5 chitosan undergoes neutralization and loses the positive charge at the physiological pH of 7.4. Researchers have developed numerous chemical derivatives of chitosan to improve its cationic properties at physiological conditions. However, such chemical modifications often lead to other drawbacks such as inconsistency, increased processing costs, risk of toxicity,
and reduction in chitosan’s molecular weight. Hence, we formulated chitosan with the (PBT®), which only relies on the physical properties and microscopic morphology of this natural material to maximize its cationic charge.
Axiostat is our first commercial product based on the PBT. Its uniform microscopic porous structure provides a unique molecular chemistry of chitosan within the matrix, which helps in retaining its positive charge for prolonged duration and even under physiological conditions. The highly porous structure of Axiostat helps by improving the tissue-biomaterial interaction both at macro and micro scales.
Firstly, when Axiostat is pressed against the wounded tissue it creates vacuous space within its pores which leads to mechanical interlocking with the tissue surface and provides instant bioadhesion. Secondly, the highly porous structure of Axiostat promotes the diffusion of surface-bound anionic molecules into the cationic pores of Axiostat which results in the diffusive adhesion, a mechanism in which surface bound molecules from tissues diffuse into the pores of Axiostat to form strong bioadhesion. Through this unique mechanism, Axiostat is able to maintain its positive charge and provide strong mucoadhesion even under physiological conditions.
Another advantage of PBT is the faster Haemostasis due to electrostatic interaction between positively charged biopolymer and the negatively charged blood cells. Through its positive charge, the PBT biopolymer attracts red blood cells (RBC) and platelets and entraps them into its porous structure, which leads to the activation of the platelets and results in formation of a strong blood clot. The combined effect of bio-adhesion and strong blood clot is instant Haemostasis.
This method of bleeding control is robust enough that it works irrespective of the natural clotting factors, hence PBT is successful even in patients taking the blood thinning medications. Lastly the enhanced cationic charge provided by the PBT biopolymer also provides strong anti-microbial properties to the material and restricts entry of external bacteria into the wound site.
Chitosan promotes Haemostasis
Mechanism of Haemostatic Action:
- Chitosan absorbs blood plasma that leads concentration of erythrocytes and platelet in the injured place.
- Chitosan causes the adhesion, aggregation, and activation of platelets.
- Chitosan promotes erythrocyte coagulation and activation due to charge-based interaction.
- Chitosan also induces blood coagulation through contact system activation
with blood coagulation factors FXI and FXII.
Figure 1: Scheme of blood clotting mechanism by Chitosan
Figure 2: Scheme of blood clotting reaction on Chitosan surface (Reproduced from Reference #3- He et al., 2013)
Chitosan induces Platelet Aggregation, Activation and Adhesion
Mechanism of platelet activation:
- Platelet gets activated when chitosan binds to the glycoprotein 2b/3a receptor located on the platelet surface
- Chitosan promotes the platelet aggregation by stimulating the influx of extracellular Ca++ ions that cause accelerating of actin cytoskeleton activation of adhered platelets and platelet shape get changed
- Chitosan enhances the platelet adhesion in the presence of adsorbed plasma and extracellular matrix proteins
Figure 1: SEM images of platelets adhered on the chitosan dressing: a) Chi-B, (b) Chi-E-90, (c) Chi-E-80, (d) Chi-E-70, and (e) Chi-E-60. m Quantification of platelet adhesion on the chitosan films. Notes: n ¼ 4, *p < 0.001 relative to the Chi-B, # p < 0.01 relative to the Chi-E-80, # # p < 0.001 relative to the Chi-E-80 (Reproduced from Reference #2- He et al., 2013)
Chitosan causes Erythrocyte Coagulation
Mechanism of erythrocyte coagulation:
- Cationic chitosan can easily bind to the negatively charged neuraminic acid-containing surface of RBC due to electrostatic interaction
- Erythrocytes lose their biconcave shape after the interaction with chitosan that leads to agglutination of RBC
- Erythrocytes are bound together by chitosan polymer chains and re-polymerize into a strong lattice that capture cells creating a stable mechanical seal
Figure 1: SEM images of erythrocyte coagulation on chitosan (A), CS 6c (BJ, CS 12c (C), and CS 1 Bc (D) (Reproduced from Reference #2- Chen et al.,2017)
Evaluation of Chitosan-based Dressings in a Swine Model of Artery-Injury-Related Shock
Pre-Clinical Studies - Swine Model
Abstract:
Uncontrolled haemorrhage shock is the highest treatment priority for military trauma surgeons. Injuries to the torso area remain the greatest treatment challenge, since external dressings and compression cannot be used here. Bleeding control strategies may thus offer more effective haemostatic management in these cases. Chitosan, a linear polysaccharide derived from chitin, has been considered as an ideal material for bleeding arrest.
This study evaluated the potential of chitosan-based dressings relative to commercial gauze to minimize femoral artery haemorrhage in a swine model. Stable Haemostasis was achieved in animals treated with chitosan fibre (CF) or chitosan sponge (CS), resulting in stabilization of mean arterial pressure and a substantially higher survival rate (100% vs. 0% for gauze). Pigs receiving treatment with CF or CS dressings achieved Haemostasis within 3.25±1.26 or 2.67±0.58min, respectively, significantly more rapidly than with commercial gauze (> 1 00min). Moreover, the survival of animals treated with chitosan-based dressings was dramatically prolonged (> 180min) relative to controls (60.92±0.69min). In summary, chitosan-based dressings may be suitable first-line treatments for uncontrolled haemorrhage on the battlefield and require further investigation into their use as alternatives to traditional dressings in prehospital emergency care.
Figure 1: The haemostatic outcomes of CF and CS dressings compared to commercial gauze application in a swine model of arterial haemorrhage. Median time to Haemostasis. Error bars represent the 95% confidence interval of the median. The chitosan-based dressing promoted Haemostasis significantly greater than commercial gauze (Reproduced from Reference #1-Wang et al., 2019)
| Outcome | CF(N=4) | CS(N=3) | Gauze(N=3)) | Overall p |
| Total time until bleeding stopped(min) | 3.25+1.26 | 2.67+0.58 | >20 | NS |
| Total resucitation fluid (mL/kg) | 30.55 | 31.58 | 188.32 | <0.001 |
| Survival rate(%) | 100% | 100% | 0% | NS |
| Survival rate(min.) | >180 | >180 | 60.92+0.69 | NS |
Table 1: Outcomes of treating a groin arterial haemorrhage. Data expressed as mean±SD and analyzed by one way ANOVA. NS=p>0. 1. ANOVA, analysis of variance; NS, not significant.
Characterization Test of Axiostat® Dressing
1. Microscopic evaluation (SEM Analysis)
Scanning electronic microscopic (SEM) images of Axiostat showing the microstructure of the Axiostat. Axiostat is a highly porous matrix with a typical honeycomb microstructure of 100-300µ. The uniform porosity of the Axiostat allows it to rapidly absorb and lock blood plasma during its haemostasis action.
2. Water Absorbency
Fluid absorbency and swelling play an important role in Axiostat haemostatic mechanism. The fluid absorption capacity of Axiostat is a minimum of 40 times its weight and the blood absorption capacity is about 15 to 20 times its weight. Once haemostasis is achieved, Axiostat is irrigated with excess water or saline, which leads to swelling of the sponge. The swollen sponge easily detaches from the wound site and gently removed it without dislodging the clot to prevent rebleeding.
3. Bioadhesive Strength
This study is used to evaluate the bioadhesive strength of Axiostat. A model of the bleeding wound is created using a piece of meatloaf and citrated blood. The blood was allowed to flow through an incision on the meat piece by using a peristaltic pump. Once Axiostat is applied on the bleeding site with pressure, it strongly adheres to the meat piece due to its highly cationic nature. The strong bioadhesion creates a mechanical seal and blocks the blood flow, which accelerates the natural blood clotting mechanism. After the Haemostasis is achieved, Axiostat is easily removed from the wound site by irrigating it with saline. The image shows the strong bioadhesion between a meatloaf weighing approximately 500g and a piece of Axiostat.
Skin Sensitization Study
Introduction: To determine the skin sensitization potential of the test item extracts using guinea pig maximization test (GPMT).
| Product Details: | |
|---|---|
| Test item name | Non Absorbable Haemostatic Dressing (sterile) |
| Batch/ Lot no. | 1039-014 |
| Manufacturing Date | September 2015 |
| Expiry Date | August 2018 |
| Appearance | Chitosan sponge |
| Composition | Poly U3-(1 ,4) - 2 amino -2 deoxy -D Glucosamine |
| Ingredients | Non-absorbable Chitosan |
| Solubility | Soluble in HCL, Acetic & Nitric acid |
| Stability | 30 °C |
| Condition | Sterile |
Methods: The method of administration is in line with the ISO 10993, Part-10 standard. For the induction phase, intradermal injections and topical application was employed. The challenge phase was accomplished by topical applications.
Results: Chitosan Non-absorbable Hemostatic Dressing (Sterile) is considered valid, as the control animals showed no skin reactions; and no significant loss of body weight. No mortality occurred in control group animals.
Conclusion: Axiostat® dressing does not induce any hypersensitivity reactions in the body.
Cytotoxicity Test
Introduction: To evaluate whether or not the test item Non-Absorbable Hemostatic Dressing (sterile) induces cytotoxicity in Balb/c 3T3 cells using elution method.
| Product Details: | |
|---|---|
| Test item name | Non Absorbable Haemostatic Dressing (sterile) |
| Batch/ Lot no. | 1039-014 |
| Manufacturing Date | September 2015 |
| Expiry Date | August 2018 |
| Appearance | Chitosan sponge |
| Composition | Poly U3-(1 ,4) - 2 amino -2 deoxy -D Glucosamine |
| Ingredients | Non-absorbable Chitosan |
| Solubility | Soluble in HCL, Acetic & Nitric acid |
| Stability | 30 °C |
| Condition | Sterile |
Methods: Rationale for assay method The NRU cytotoxicity assay procedure is a cell survival/viability chemosensitivity assay based on the ability of viable cells to incorporate and bind neutral red dye. Specified in ISO 10993, the Part-5 standard is an appropriate test to evaluate in vitro cytotoxicity of medical devices.
Results: Chitosan Non-absorbable Hemostatic Dressing (Sterile) is considered as non-cytotoxic to Balb/c 3T3 cell lines, under the conditions of the test.
Conclusion: Axiostat® dressing does not have any toxic effect on the mammalian cells.
Acute Systemic Toxicity Test
Introduction: To determine the acute systemic toxicity potential of the test item Non-Absorbable Hemostatic Dressing (sterile) extracts in Swiss albino mice.
| Product Details: | |
|---|---|
| Test item name | Non Absorbable Haemostatic Dressing (sterile) |
| Batch/ Lot no. | 1039-014 |
| Manufacturing Date | September 2015 |
| Expiry Date | August 2018 |
| Appearance | Chitosan sponge |
| Composition | Poly U3-(1 ,4) - 2 amino -2 deoxy -D Glucosamine |
| Ingredients | Non-absorbable Chitosan |
| Solubility | Soluble in HCL, Acetic & Nitric acid |
| Stability | 30 °C |
| Condition | Sterile |
Methods: The extracts (Physiological saline and Cottonseed oil) were administered without any dilution and the maximum dose volume used were 50 ml/Kg and 50ml/Kg for IV and IP route, respectively. This is in line with the ISO 10993, Part-11 standard.
Results: Chitosan Non-absorbable Hemostatic Dressing (Sterile) is considered valid, as the control animals showed no biological reactions; and no significant loss of body weight. No mortality or abnormal behavior such as convulsion or prostration was occurred in control group animals.
Conclusion: Axiostat® dressing did not show any Systemic toxicity and hence meets the requirements of ISO 10993, Part-11:2006 (E).
Intracutaneous Reactivity Test
Introduction: To determine the irritation potential of the test item extracts
following intracutaneous injection into New Zealand white rabbits.
| Product Details: | |
|---|---|
| Test item name | Non Absorbable Haemostatic Dressing (sterile) |
| Batch/ Lot no. | 1039-014 |
| Manufacturing Date | September 2015 |
| Expiry Date | August 2018 |
| Appearance | Chitosan sponge |
| Composition | Poly U3-(1 ,4) - 2 amino -2 deoxy -D Glucosamine |
| Ingredients | Non-absorbable Chitosan |
| Solubility | Soluble in HCL, Acetic & Nitric acid |
| Stability | 30 °C |
| Condition | Sterile |
Methods: The extracts (Physiological saline and Cottonseed oil) were administered intracutaneously without any dilution and the dose-volume used was 0.2 ml per injection. This is in line with the ISO 10993, Part-10 standard.
Results: Chitosan Non-absorbable Hemostatic Dressing (Sterile) is considered valid, as the control animals showed no skin reactions; and no significant loss of body weight.
No toxicity or mortality occurred in control group animals.
Conclusion: Axiostat® dressing did not show any intracutaneous reactivity and meets the requirements of ISO 10993, Part-10:201 O(E)
Blood Clot Test
Axiostat Vs. Other Haemostatic Gauze
REFERENCES
- Maksym P\/, Vitalii S. Chitosan as a Haemostatic agent: current state. Eur J Med Ser B. 2015;2(1 ):24-33.
- Hu Z, Zhang DY, Lu ST, LJ PW, LJ SD. Chitosan-based composite materials for prospective Haemostatic applications. Marine drugs. 2018 ;16(8):273.
- He Q, Gong K, Ao Q, Ma T, Yan Y, Gong Y, Zhang X. Positive charge of chitosan retards blood coagulation on chitosan films. Journal of biomaterials applications. 2013;27(8):1032-45
- Zhou X, Zhang X, Zhou J, Li L. An investigation of chitosan and its derivatives on red blood cell agglutination.
RSC Advances. 2017; 7(20): 1224 7 -54. - Chen Z, Yao X, Liu L, Guan J, Liu M, Li Z, Yang J, Huang S, Wu J, Tian F, Jing M. Blood coagulation evaluation of N-alkylated chitosan. Carbohydrate polymers. 2017; 173:259-68
- Arand AG, Sawaya R. lntraoperative chemical HAEMOSTASIS in neurosurgery. Neurosurgery. 1986 Feb 1; 18(2):223-33.
- Wang YH, Liu CC, Cherng JH, Fan GY, Wang YW, Chang SJ, Hong ZJ, Lin YC, Hsu SD. evaluation of chitosan-based
Dressings in a Swine Model of Artery-injury-Related Shock. Scientific reports. 2019 ;9(1 ): 1 -7.
Bioactive Microfiber Gelling Technology (BMGTM)
The BMG dressings are manufactured using our proprietary patent-pending technology that purifies the biopolymer and makes it superabsorbent. The surface properties of these fibers are tailored in a way that they swell once exudate is absorbed but do not disintegrate when over-saturated, a common problem with currently available technologies. On absorbing the wound exudate, our BMG-based MaxioCel dressings transform into a cohesive and conformable gel. BMG technology-based gelling action in combination with unique molecular chemistry of biopolymer induces higher absorbency and mechanical strength to MaxioCel and facilitates the creation of an optimal environment for rapid wound healing.
BMG technology incorporates superabsorbent property to biopolymer fibers to lock-in the absorbed fluid within their fiber network chains significantly more than other wound care dressing through capillary action. When this wound dressing is used on highly exudating wounds, it sequesters the exudate fluid and damaged cell, infected necrotic tissue and bacteria present in it, thereby trapping them. This leads to well management of drainage and removal of cellular debris from the wound site. In a way it acts as an autolytic debridement agent. Its fluid retention, prevents wound maceration as well, keeping the wound clean and sufficiently moist.
In addition, BMG Technology helps to prevent maceration at wound site by wicking wound exudate fluid only vertically, not in lateral direction. Due to this vertical wicking property, MaxioCel dressing can easily hold the absorbed wound exudates for a longer period of time without spreading throughout the surrounding area. Moreover, BMG technology provide intimate contact for MaxioCel dressing at wound site due to electrostatic interaction between positively charged chitosan microfiber and negatively charged particles of necrotic tissue and cell debris. BMG Technology also delivers barrier to bacteria and broad-spectrum antimicrobial property to MaxioCel due to the presence of activated and positively charged chitosan microfiber.
Chitosan Promotes Haemostasis
- Chitosan absorbs blood plasma that leads to the concentration of erythrocytes and platelets in the injured place.
- Chitosan causes the adhesion, aggregation, and activation of platelets.
- Chitosan promotes erythrocyte coagulation and activation due to charge-based interaction.
SEM Image of Chitosan and RBC interaction
SEM Image of Chitosan and platelet interaction
Chitosan Promotes Re-Epithelialization
- Chitosan stimulates the proliferation of dermal fibroblast and allows fibrous tissue formation.
- Chitosan interacts with growth factors of serum and metal ions such as calcium that induce rapid proliferation of fibroblast.
- Chitosan inhibits the proliferation of keratinocytes.
Initial screening of chitin/Chitosan samples for effect on fibroblast proliferation in vitro. Human dermal fibroblasts (C520) were treated with various Chitosan samples for 3 days. The 3-H thymidine cell proliferation assay was then performed. Data (n=3 ±SEM) are presented as percentage of the controls (no polymer present) (*P (0.05, **P (0.01, ANOVA).
Antimicrobial Activity of Chitosan
- Cationic Chitosan binds to negatively charged cell walls of microorganisms which results in the leakage of proteinaceous and other intracellular constitutes
- Chitosan inhibits the mRNA and protein synthesis via the penetration of Chitosan into the nuclei of microorganisms.
- Chitosan provokes cell osmosis of the microorganisms.
Log reduction of suspended cells (■) and biofilm (■) cells of five bacterial strains, after 60 min exposure to 0.01 % (■), 0.1 % (■), and 1 % (■) Chitosan. Statistical comparison was made between planktonic and biofilms log reduction values exposed to the same Chitosan concentration. Values showing a different superscript (a>b) letter were significantly different (p < 0.05) (n = 6). Reproduced from Orgaz B. et al.
Analgesic Effect Of Chitosan
- Chitosan absorbs the proton ions released at the inflammatory site.
- Chitin and Chitosan lower Bradykinin production at the inflammatory site.
- Chitosan also inhibits the Phospholipase A2. (PLA-2) activity, in turn blocking the Arachidonic acid pathway.
Effect of Chitin and Chitosan on bradykinin production. Bradykinin levels in the 1 % and 10% Chitosan/acetic acid solution were decreased by 16. 7% and 22.2% respectively compared with control (0.5% Acetic acid).
Anti-Inflammatory Property Of Chitosan
- Chitosan inhibits inflammation mediators such as Interleukin (IL)- 2, IL-4, IL-6, IL-10 and IL-13.
- Chitosan causes the reduction in pro-inflammatory cytokines such as TNF-a.
- Chitosan down regulates the NF-kf3 expression and AP-1 activation.
Scar Prevention by Chitosan
- Chitosan gradually degrades into N-acetyl-b-D-glucosamine, which initiates hyaluronic acid synthesis at the wound site that helps in faster scar improvement.
- In the presence of Chitosan, type IV collagen produced is in the form of fine reticulin like fibrils rather than mature bands of dense collagen which leads to scarring.
- Chitosan significantly decreases the expression of TGF-[31 factors by blocking the cyclooxygenase and arachidonic acid pathway that improve the scar.
After 21 days, wound surface with Control(Cotton gauze)
After 21 days, the wound surface showed scar improvement with Chitosan dressing
Antimicrobial Assessment of a Chitosan Microfibre Dressing: A Natural Antimicrobial
Abstract
Objective: This study was undertaken to assess the antimicrobial properties of the Chitosan-based microfibre namely Kytocel, wound dressing using a variety of methods commonly used to assess other antimicrobial dressings.
Method: The zone of inhibition (ZOI) assay, challenge test (log reduction), time-to-kill, and an in vitro wound model were all used in this report. Representative Gram-positive and Gram-negative bacteria were used and one yeast, Candida Albicans.
Results: The ZOI test showed no observable zones around the dressing but killed the organisms underneath the dressing. There was a >3 log reduction of Staphylococcus Aureus and Escherichia Coli within two hours and >3 log reduction against Pseudomonas Aeruginosa and Candida Albicans between four and 24 hours in the challenge test. In the wound model, there was a 2 log reduction of Escherichia Coli within the wound model and in the sponge and culture medium below the dressing.
The area underneath the dressing, following removal of microfibre Chitosan dressing, showing killing of the organisms Staphylococcus Aureus, Escherichia Coli, Pseudomonas Aeruginosa and Candida Albicans.
| Dressing | Zone of inhibition under dressing | Growth in zone of clearing after re-incubation |
| Microfibre Chitosan dressing | Yes, 30 x 30 mm | No growth |
| Microfibre control dressing(Aquacel) | None | Full growth |
| Gauze control(Tricotex) | None | Full growth |
Sequestration Test of 100% Chitosan Dressing
The color sequestration test of Chitosan wound dressing presented here shows the property of the Chitosan fibres to lock in the absorbed fluid within their chains.
- When the dressing is dipped in the colored solution, it rapidly turns into a gel and traps the color.
- The same dressing, when sequentially dipped in different colored solutions, shows a clear demarcation between the hydrated part with different colors and the dry part.
- The colors do not spread outside the defined stripes clearly indicating the extensive fluid retention capacity of the fibres.
- Finally, when the dressing is dipped in water, the water remains clear showing that the trapped colors aren’t released. When this wound dressing is used on highly exudating wounds, it sequesters the fluid and the cells and bacteria present in it, thereby trapping them. Its fluid retention, prevents wound maceration, keeping the wound clean and sufficiently moist. This creates a suitable environment for the wounds to heal.
Exudate absorption & locking
- Fluid absorption capacity: 30 times the weight of dressing.
- Once absorbed the exudate is locked within the fibres of the dressing.
- The gelling fibres prevent wicking of exudate into surrounding skin.
Lateral wicking of exudate from dressing may lead to leakage and maceration of surrounding skin. MaxioCel reduces the risk of maceration and leakage due to its unique vertical wicking properties. It can easily hold the absorbed wound exudates for a longer period of time without spreading throughout the surrounding area.
Dispersion Test & Wet Strength
Fluid absorption capacity: 30 times the weight of dressing. Wet strength of MaxioCel is around 3 times greater than the traditional gelling fibre dressing. Its outstanding strength makes it
- Intact during dressing change for a longer time.
- Painless easy removal from the wound surface.
Acute Systemic Toxicity Test
Introduction: To assess the health hazards that are likely to arise from acute systemic exposure to the leachable{s) of test item, Chitosan Wound Dressing extracted in polar (normal saline) and non-polar (corn oil) solvents in accordance with ISO 10993-11:2006(E).
| Product Details: | |
|---|---|
| Test item name | Chitosan wound dressing |
| Batch/ Lot no. | CWD004-81 |
| Manufacturing Date | Jan 2018 |
| Expiry Date | Dec 2020 |
| Appearance | Non-woven fabric, slight yellow in Color |
| Composition | 100% Chitosan |
| Storage | Room temperature (24° C ± 3° C) |
| Condition | Sterile |
Methods: The polar extracts were administered to rats intravenously through tail vein and non-polar extracts were administered by intraperitoneal injections with the dose volume of 1 0ml/kg body weight. This is in line with the ISO 10993-11 standard.
Results: There was no morbidity or mortality observed in the present study. There were no clinical signs observed at any time during the study. Similarly, no signs of erythema and/or edema noticed at the injection sites. At necropsy, no external or internal gross lesions were observed in any of the animals.
Conclusion: Chitosan Wound Dressing did not produce any adverse effect when administered as an extract of polar (0.9% w/v physiological saline) and non-polar (corn oil) vehicles by intravenous and intraperitoneal routes respectively in female Wistar rats, hence Chitosan wound dressing meets the requirements of ISO 10993-11.
Cytotoxicity Test
Introduction: To evaluate the cytotoxic potential of the Chitosan wound dressing in L929 cell lines using MTT assay as per the ISO 10993-5:2009(E).
| Product Details: | |
|---|---|
| Test item name | Chitosan wound dressing |
| Batch/ Lot no. | CWD004-81 |
| Manufacturing Date | Jan 2018 |
| Expiry Date | Dec 2020 |
| Appearance | Non-woven fabric, slight yellow in Color |
| Composition | 100% Chitosan |
| Storage | Room temperature (24° C ± 3° C) |
| Condition | Sterile |
Methods: L929 Cells (1 x1 0A4cells/well) were treated with four different concentration of test item (Chitosan Wound Dressing) such as 100%, 75%, 50%, and 25% which includes Vehicle, Positive control (0.1 % of phenol) and Negative control (100 % of HOPE extracts) in both polar and non-polar vehicles which were incubated at 37±1 °C for 24±2 hours in a humidified atmosphere containing 5 ± 1 % CO2. After 24 hours incubation cell viability measured via MTT assay. Cell viability below 70% considers test item to be cytotoxic in nature.
Results: Cell viability of Vehicle control and HOPE extracts were greater than 70% and that of phenol was less than 70% in both polar and non-polar vehicles. The cell viability of 100% extracts of test item in both polar and non polar vehicle was 98.45% and 87.67%.
Conclusion: Chitosan Wound Dressing is non-cytotoxic in nature in both polar and non-polar vehicles as per ISO 10993-5 guideline.
Acute Dermal Irritation Test
Introduction: To assess the skin irritation/corrosion potential of Chitosan Wound Dressing after single dermal application in New Zealand White rabbits and evaluate the reversibility/irreversibility of the effects observed. The experimental method was designed to meet the requirements of the ISO 10993-10:201 O(E).
| Product Details: | |
|---|---|
| Test item name | Chitosan wound dressing |
| Batch/ Lot no. | CWD004-81 |
| Manufacturing Date | Jan 2018 |
| Expiry Date | Dec 2020 |
| Appearance | Non-woven fabric, slight yellow in Color |
| Composition | 100% Chitosan |
| Storage | Room temperature (24° C ± 3° C) |
| Condition | Sterile |
Methods: Four test sites on the female New Zealand White rabbits (Right side cranial end, Left side cranial end, Left side caudal end, and Right-side caudal end) were prepared by removal of the fur. The site on the Right side cranial end was considered as Polar control and applied with the vehicle (normal saline) and the site on the Left side caudal end was considered as non-Polar control and applied with the vehicle (corn oil} only. The sites on the Left side cranial end and Right-side caudal end were applied with 0.5ml of the Test Item prepared with normal saline (Polar) and corn oil (non-Polar) respectively and covered with a gauze patch loosely held in contact with the skin by semi-occlusive dressing for 4 hours. All the test sites were examined after removing the patch at 24, 48 and 72 hours post removal of the patches and dermal reactions (erythema and edema) were graded and recorded.
Results: No evidence of severe irritant or corrosive effect was noticed at any of the test sites. Mean of Erythema and Edema score determined in 3 of 3 rabbits after 24, 48 and 72 hours observation was ‘O’. Further, there was no mortality, or any other adverse clinical signs noticed in any of the animals tested.
Conclusion: Chitosan Wound Dressing did not produce any signs of skin irritation (Mean Score of ‘O’ for Erythema and Edema in 3 of 3 rabbits at 24, 48, and 72 hours) and could be considered as Non-Irritant to Skin of female New Zealand White rabbits.
Antifungal Test
Introduction: To assess the antifungal activity of the Chitosan wound dressing as per the MTCC 30-2013 protocol.
| Product Details: | |
|---|---|
| Test item name | Chitosan wound dressing |
| Batch/ Lot no. | CWD004-81 |
| Manufacturing Date | Jan 2018 |
| Expiry Date | Dec 2020 |
| Appearance | Non-woven fabric, slight yellow in Color |
| Composition | 100% Chitosan |
| Storage | Room temperature (24° C ± 3° C) |
| Condition | Sterile |
Methods: The solid agar medium in the petri dish is inoculated with the spore suspension before placement of the test sample. The test sample is placed on top of the inoculated agar medium and after placement, the top of the sample is also inoculated with the spore suspension. The petri dishes are sealed to maintain humidity while being incubated. 100% Chitosan Room temperature (24° C ± 3° C) The inoculated test sample is evaluated after 7 days and are rated on whether they have macroscopic (visible with the naked eye), Sterile microscopic, or no growth.
Conclusion: The sample 1801676ffi/2 showed Antifungal activity against Aspergillus niger ATCC 6275, when tested according to MTCC Test Method 30-2013, Method Ill.
REFERENCES
Chen Z, Yao X, Liu L, Guan J, Liu M, Li Z, Yang J, Huang S, Wu J, Tian F, Jing M. Blood coagulation evaluation of N-alkylated Chitosan. Carbohydrate polymers. 2017; 173:259-68.
He Q, Gong K, Ao Q, Ma T, Yan Y, Gong Y, Zhang X. Positive charge of Chitosan retards blood coagulation on Chitosan films. Journal of biomaterials applications. 2013;27(8):1032-45.
Maksym PV, Vital ii S. Chitosan as a Haemostatic agent: current state. Eur J Med Ser B. 2015;2(1 ):24-33.
Howling GI, Dettmar PW, Goddard PA, Hampson FC, Dornish M, Wood EJ. The effect of chitin and Chitosan on the proliferation of human skin fibroblasts and keratinocytes in vitro. Biomaterials. 2001 Nov 15;22(22):2959-66.
Hamilton V, Yuan Y, Rigney DA, Puckett AD, Ong JL, Yang Y, Elder SH, Bumgardner JD. Characterization of Chitosan films and effects on fibroblast cell attachment and proliferation. Journal of Materials Science: Materials in Medicine. 2006 Dec 1 ;17(12):1373-81.
Goy RC, Britto DD, Assis OB. A review of the antimicrobial activity of Chitosan. Polimeros. 2009;19(3):241-7.
Ahmed AA, Sofy AR, Sharai AM. Effectiveness of Chitosan as a naturally-derived antimicrobial to fulfill the needs of today’s consumers looking for food without hazards of chemical preservatives. Microbial RES J. 2017; 7:55-67. 3. Orgaz B, Lobete MM, Puga CH, San Jose C. Effectiveness of Chitosan against mature biofilms formed by food-related bacteria. International journal of molecular sciences. 2011 Jan;12(1 ):817-28.
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