3D Printed Lanolin Based Sodium Alginate Wound Dressings

Abstract

This study, aims to develop a realistic view of creating novel wound dressing materials by making use of 3D printing technology. Wool wax which is known as textile waste is used as an agent material. Various concentrations of wool wax (lanolin) and sodium alginate-based scaffolds were developed by additive manufacturing technology. The use of lanolin as wound dressing material and 3D production has been successfully achieved in the study. It is found that the pore size of scaffolds is increased as lanolin concentration increased. The results showed that the optimum concentration of wound dressing was developed by 2% of lanolin and 4.5% sodium alginate solution. The antimicrobial action of the developed structures was performed against Escherichia coli. The result of antibacterial activity demonstrates that the lanoline addition in the scaffolds provides antibacterial activity. The mechanical properties, such as swelling and degradation were also studied. The discharge mechanism of the scaffold was investigated by using agar gel chromatography and chromatography method. In this study it is investigated that the 3D-printed lanolin structures have a great potential to be used as wound dressings.

Keywords: 3D printing, wool wax (lanolin), sodium alginate, wound dressing, industry, additive manufacturing

1. Introduction

Burn wounds are caused by chemical, electrical, fire, and sun contact with human skin, irritations, and traumas. As mentioned within the literature, burn wounds are characterized by the severity of injury to the skin. The Wallace rule of nines is applied to work out the depth of the burn. As given in Figure 1, there are mainly three significant sorts of burn wounds 1.

Abbildung in dieser Leseprobe nicht enthalten

Abbildung in dieser Leseprobe nicht enthalten

Figure 1 : Characterization of the burn wound a) first-degree burn wound b) second-degree burn wound c) third-degree burn wound. (authors own work)

First-degree burn (epithelial burns) - Skin is erythematic without vesicating. Second-degree burns - Involving epidermis and variable thickness of the dermis. This is often also again divided into different types like second-degree superficial, where vesicating and inflammation is seen in the skin as the only papillary dermis is involved. Second-degree deep -eschar formation is seen because it involves deep reticular dermis. In interrogation burn, also referred to as full-thickness burns, eschar formation is present 2.

Abbildung in dieser Leseprobe nicht enthalten

Figure 2 : The Wallace rule of nines. (authors own work)

Wound healing ends with re-epithelization and restoration of the epidermal barrier. Healing and management of burn wounds are different from other wounds. It takes years for scar recovery even after complete epithelization. As reviewed current situation globally, in India, over 1 000 000 people are moderately or severely burnt per annum. Nearly 173000 Bangladeshi children are moderately or severely burnt per annum. In Bangladesh, Colombia, Egypt, and Pakistan, 17% of youngsters with burns have a short-lived disability, and 18% have a permanent disability. Burns are the second most typical injury in rural Nepal, accounting for five disabilities. In 2008, over 410 000 burn injuries occurred within America, with approximately 40 000 requiring hospitalization 3.

In this year, the wound dressing market is 7.0 billion USD. Wound care is vital since prehistory. Although wounds can heal naturally, hunter-gatherers empirically discovered many factors like herbs for accelerating the process of wound healing. There are many milestones. For example, wound dressing is developed in ancient Greek, ancient Egypt, the 19th century, 20th century, and 21st century. A short history of the natural wound dressing materials: First of all, in old Greek, the herbal treatment industry was so huge that traders skipped doctors and sold herbal treatment. This is the foundation of the primitive pharmaceutical sector. The earliest list of herbal medicine was written on the papyrus, which includes 850 plant medicines by Diocles of Carustius, the Greek philosopher Aristotle. This paper is the initial of herbal scientific research. Furthermore, ancient Greek is aware of wound closure; they tried the close wound by using herbs. Consequently, ancient Greek is crucial in wound dressing. Secondly, ancient Egypt believed that closing wounds prevent from external evils spirit. They used animal grease, honey as a barrier to the environment. Obviously, their wound dressings are animal grease and honey. The use of honey and animal grease is written in the Ebers Papyrus circa 1500 BC. Briefly, ancient Egypt used herbs and animal grease as a wound dressing. Thirdly, the perception of wound care changed in the 19th century with the renaissance, thanks to the evaluation of microbiology and pathology. This new conception began with Ignaz Philipp Semmelweis. He discovered the importance of handwashing in maternal deaths. Then, Robert Wood Johnson I, who is co-founder of Johnson & Johnson, sterilized wound dressings with dry heat, pressure and steam. Sterilization of wound dressing is a crucial step after the Egyptians and Greeks centuries. In the 20th century, polymer synthetic wound dressings began with the development of polymers.

Fourthly, in the 1950's nylon, polyethylene, polypropylene and polyvinyl, which are fibrous synthetics used as a wound dressing, explored the protection of wounds and accelerated the healing process. Afterward, in the 1960s, George Winter and Howard Maibach realized that moist wound dressing enhances re-epithelialization and healing of the wound. Fifthly, in the 1990s, composite and hybrid polymers were used as a wound dressing. Also, a new class of wound dressing which is called living skin equivalent has risen with the development of biotechnology and tissue engineering. The main property of living skin equivalent is the release of growth factor for wounds, serving as a cellular matrix. Also, biomembranes, skin substitutes developed, and the concern of burn wound pain was reported. In brief, the 19th and 20th centuries bring a new dimension in wound dressing. Sixthly, in the 21st century, different materials and different types of wound dressing were produced. For instance, dry dressings wet to dry dressings, chemical impregnated dressings, foam dressings, alginate dressings, hydro fiber dressings, transparent film dressings, hydrogel dressings, hydrocolloid dressings, self-adaptive dressings, functional cosmetics. In conclusion, there are sharp- lines in ancient Greek, ancient Egypt, the 19th century, 20th century, and 21st century in wound dressing 4.

Abbildung in dieser Leseprobe nicht enthalten

Figure 3:The history of the wound dressing. (authors own work)

There is another issue that burns are dynamic and alter in appearance, particularly within the first 48 hours (1728*102s). Therefore, it's the practice of the burn services to review burns after 48 hours (1728*102s) before decisions regarding definitive dressings or surgery to be made. The initial burn dressing should be one that will remain intact for 48 hours (1728*102s) and stop infection. It is a protocol within the burn service to decorate all burns with dressing for 48 hours (1728*102s) 5. Additive manufacturing may be a technology that builds three-dimensional solid objects from their digital models; this enables to pick material layer by layer. Due to manufacturing complex, shapes additive manufacturing may be a part of modern manufacturing. Using additive manufacturing can reduce the environmental effect and make sustainable yield. To accomplish the design problem of additive manufacturing, inverse problem-solving methods are often used. During this study, to unravel the difficulties when fabricating wound dressing, the inverse problem-solving method is employed 6.

Abbildung in dieser Leseprobe nicht enthalten

Figure 4: Problem-solving method. (authors own work)

The primary object of this study is to develop novel structures which may be applied to the second degrees wounds, which entail innovative wound dressings to move at the primary stage and, through the healing process, protect the burn wounds. The scaffold acts as a barrier between air and skin. It prevents the connection of bacteria, germ, dust, and wound. It is aimed that the wound dressings provide a suitable environment for healing. Commercially, the utilization of lanoline in medical cream is common for burn wound treatment. It is well-established that lanoline has a reepithelization rate, the thickness of the dermis and cell counting impact 7. There are some lanolin-based skin creams; however, there are not lanolin-based 3D-printed structures which is one of the important novelty of this work. In today's world, sustainability, recycling and renewability are significantly important and challenging. Nowadays, the priority has been growing over the disposal of wastes produced by textile industries. The utilization of wool is so prevalent that the precise parts of the wool are used in textile manufacturing. Textile industries based wastes are not used as a by-product for intelligent and technical textiles. Lanolin also referred to as wool oil/wax/grease, has prominent molecular alcohol and grand molecular acid esters. Wool wax may be a yellowish substance, whitish color and soluble in organic solvents. The removal operation of wool wax from wool is completed during the washing process with emulsification. If requested, it's recoverable from the washing bath. When wool wax first leaves from washing bath, it is dirty yellowish in color, with the smell of sheep. After the purification period, wool wax attains odorless, light yellowish color with 38-44°C freezing point commercial material. Lanoline is acquired after diluting purified wool wax.

Abbildung in dieser Leseprobe nicht enthalten

Figure 5 : The structure of wool: a) cuticula, b) cortex cell, c) microfibril, d) microfibril, e) molecular chain, f) alpha helix. (authors own work)

1 Materials and Methods

1.1 Chemicals

Sodium alginate (SA) with a mean relative molecular mass of 216.121 g/mol was purchased from Sigma-Aldrich (Istanbul, Turkey). Salt dihydrate (CaCl2.2H2O) was purchased from Merck (Darmstadt, Germany) and was to be used as crosslinker. BS (phosphate-buffered saline), pH 7.4 and pH 2.0 solutions were bought from ChemBio Laboratory Research (Istanbul, Turkey). Mueller Hinton agar (CM0337B, Oxoid, Thermo Fisher, Basingstoke, UK) and Mueller Hinton broth media (CM0405B, Oxoid), and 10 μg ampicillin containing disks (CT0002B and CT0003B, Oxoid) were obtained for antibacterial activity assays. Escherichia coli ATCC® 25922™ standard strains were used for antibacterial testing. Dichloromethane and dimethylformamide were bought from Sigma Aldrich, USA. Wool oil was kindly provided by Pozitif Wool Ltd., Uşak, Turkey.

1.2 Preparation and Characterization of Scaffolds

In the present study, the animal oil-modified alginate scaffolds were developed and characterized. For this objective, sample 1 solution was prepared. Sample 1 solution was found to be optimum for the 3D printing method, and animal oil was added to the solutions at different ratios of 0.5%, 1%, 2%, 5%, 10%. The sum of the answer contents is given in Table 1. Firstly, sodium alginate was dissolved in the distilled water, 20 ml (2*10-5 m3) of sample 1 was stirred at 800rpm for 3 (108*102s) hours at room temperature. Secondly, different animal oil solutions were taken and added to 10 ml (10-5 m3) sample 1 solution. Then, animal oil sodium alginate solution was stirred in vortex machine for 5 min (300s) at room (20-22Co) temperature. The solutions were named as sample 1 (4.5% sodium alginate), sample 2 (0.5% animal oil 4.5% sodium alginate), sample 3 (1% animal oil 4.5% sodium alginate), sample 4 (2% animal oil , 4.5% sodium alginate), sample 5 (5% animal oil 4.5% sodium alginate), sample 6 (10% animal oil 4.5% sodium alginate). Thirdly, to take out the scaffolds from lamella 1% CaCl2 dehydrate used as crosslinker.

1.3 Optimization of Wool Oil

Hydrous lanolin or lanolin contains 25% water. It is imperative to mention that during this study, thanks to the properties of lanolin for medicinal usage purposes, 2% of lanolin is kept the maximum ratio. From the perevios study it is observed that lanolin during a concentration of up to two wasn't effective within the healing process, mainly within the assessment of outcomes in reference to time 8. Wool oil dichloromethane/dimethylformamide (dcm/dmf) with ratio 4/1 solution's density synchronized with lanoline. For this aim 0,148g (148*10-6 kg) animal oil was dissolved in dichloromethane/dimethylformamide (dcm/dmf) with ratio 4/1. Afterward, 4.5% sodium alginate solution was prepared and mixed with discrete animal oil solution (0.5%, 1%, 2%, 5% and 10%). After mixing animal oil solution with 4.5% sodium alginate, the color change was observed, transparent to white. Since the animal oil concentration was increased,white color visibility was increased. Furthermore, after mixing animal oil solution with 4.5% sodium alginate, odor change was observed. Then, to get rid of the odor, it was ventilated. Three days experiment was conducted. Consistent with the experimental results, the animal oil prevented sodium alginate degradation.

Abbildung in dieser Leseprobe nicht enthalten

Figure 6: As seen in the figure, wool oil was pretended corruption of sodium alginate solution. a) 3 day after preparation of solution of sample2 (0.5% wool oil 4.5% sodium alginate solution). b) 3 days after preparation of a solution of sample3(1% wool oil 4.5% sodium alginate solution). (authors own work)

1.4. 3D Design of Scaffolds

In this study, the weave fabric structures were designed and analyzed by the 3D printing technique. 3D scaffolds' design was inspired by twill woven structure. 9.

Twill is employed in many areas of textiles and it's also suitable for wound dressing applications. The size of scaffolds was calculated and designed consistent with Wallace's rule of nines. The scaffold was produced as 20mm×20mm(2*10-2m×2*10-2m); the size can change depending on the appliance area on the body. The scaffold 3D design was made in Adobe Fusion 360. The designed wound dressings were manufactured employing a modified extrusion 3D printer (Ultimaker 2 + Netherlands). 10cm×10cm(0.1m×0.1m) wound dressing also produces to control the size of wound dressing effect of deformation.

Abbildung in dieser Leseprobe nicht enthalten

Figure 7: Designing of scaffolds. a) Top view of the scaffolds. b) Side view of the scaffolds. (authors own work)

1.4 Characterizations

1.4.1 Fourier Transform-Infrared Spectroscopy (FT-IR)

Chemical characterization of wound dressing was applied to employ a Fourier Transform-Infrared Spectroscope (Jasco, FT-IR 4700). The FT-IR spectrum was found at 400 and 4000 cm-1 scanning range and 4 cm-1 resolution. This experiment was done to manage the modification of lanolin to SA.

1.4.2 Antibacterial Essay

All scaffold was cut and sterilized using UV light (254 nm). The antibacterial assay was done according to the Kirby-Bauer procedure. The media was Mueller Hinton agar 4mm (4*10-3m) deep and poured into 150mm (15*10-2m) Petri dishes. Escherichia coli bacteria were used. The pH level of the agar was 7.2. swab, which is sterile, was placed into the broth culture using the aseptic method. The plate was rotated 90° and was streaked again therein direction 3 times. It was dried for 6 minutes (360s). Finally, the ampicillin antibiotic disk was used. The plate was incubated at temperature 37°C.

1.4.3 Swelling Analysis of Scaffolds

Water holding capacities of the scaffolds are crucial for burn wound treatment. Swelling capability may be a significant index for a scaffold that helps wound healing. Swelling tests were administered to specify the water-holding capability of scaffolds. The dry weights of the scaffolds were measured (W0). Then the scaffolds were inserted into 1 ml (10-6m3) of PBS pH 7.4 at 37 °C, at 250 rpm. They were incubated in the thermal shaker. Samples were far from the buffer after appropriate intervals of 10s using Whatman paper and their weights were determined (Ws). The water holding rate of the samples was calculated using the subsequent equation.

1.4.4 Degradation Analysis of Scaffolds

The degradation of scaffolds was decided using the gravimetric method. The weights (W0) of the scaffolds which is not contain liquid were determined. They were inserted into 1 ml (10-6m3) of PBS pH 7.4 at 37 °C, at 250 rpm. They were incubated in the thermal shaker. At the top of the acceptable interval, the samples were dried for 2.5h (9*103s) using Whatman paper at room temperature. Then weighed (W) and therefore, the deformation values of the scaffolds were calculated by the subsequent formula.

1.4.5 pH Analysis of Scaffolds

In the present study, experiments are administered to work out the pH of the scaffold. Firstly, sample 1, sample 2, sample 3, sample 4, sample 5, sample 6 were taken in the middle of Petri dishes. Then, two different solutions were prepared in 0.5 ml (5*10-7m3) distilled water using 0.184 g (184*10-6kg) salt dihydrate (CaCl2) and 1.148g (1.148*10-3kg) common salt (NaCl). The pH measurement was appropriated for a trial period of seven days. The pH meter was immersed in each of the solutions. In each measurement pH meter calibrated with 4.0 pH solution and 7.0 pH solution at temperature. Results were controlled with pH paper.

1.4.6 Paper Chromatography

Whatman paper was used. Paper was cut in the dimensions of Petri dishes. Paper was wet using 0.73 ml (73*10-8m3) Fe3Cl solution and waited for a quarter-hour. They were then transferred to petri dishes. Then using pressure, sample 3 solution was put at the center of the paper. Then diffusion distances was measured. Diffusion distance was calculated using the formula. Colorful area(x), scaffold area(y) calculating average.

Diffusion distance=

Results found were determined with mathematical formulas and graphs. Diffusion distance versus time graph decided y=axb parabolic graph.

1.4.7 Microscopy

To determine morphological character of scaffolds, microscopy was used. Consistent with lanolin concentration, notable changes in scaffold were seen.

1.4.8 Statistical Analysis

Using R studio software, the mean and variance was calculated. All measurements are done triple. Statistical analysis of experimental results was done using R studio software.

2 Results and Discussion

2.1 Synthesis Result

Many different commercial sorts of sodium alginate scaffolds material, also as medical creams containing lanoline, is out there on the present market. This study aimed to organize sodium alginate incorporated with animal oil wound dressing. For this purpose, alginate hydrogels with and without animal oil (sample 1, sample 2, sample 3, sample 4, sample 5, sample 6) were prepared to be used as a wound dressing. The scaffolds are successfully designed and printed by making use of the 3D printer. The optimum printing was observed in Sample 3. CaCl2.2H2O was used as a crosslinker. Animal oil revenged degradation of sodium alginate solution. The previous studies showed that less than 2% lanolin doesn't have a medical effect. In the current study, optimum printing is additionally in sample 3. The swelling tests have been performed and oil concentration increased by the swelling ratio. There are not any worthy changes in the degradation percentage on tested samples. The very best degradation percentage was observed in sample 6. Due to the very fact that animal oil softened alginate, sample 6's degradation percentage is found to be the very best value. The pH of the wound dressing is substantial for burn wound healing. The pH of scaffolds appropriates for burn wound healing in sample1, sample 2, sample 3, sample 4, sample 5 and sample 6. It's been seen that the animal oil concentration decreased the pH values. The pH of scaffolds helps in wound alleviate by managing wound infection, enlargement of antimicrobial action, altering protease activity, releasing oxygen, reducing the pestilential of bacterial end products, and intensifying epithelization and angiogenesis.

2.2 Characterization Result

2.2.1 Fourier Transform-Infrared Spectroscopy (FT-IR)

FT-IR uses the infrared region of the spectrum. It measures what proportion of infrared was absorbed by the bonds. It provides a unique fingerprint to molecules. Different functional groups absorb unique heat. During this study, FT-IR was used only to manage the incorporation of lanolin into SA. As seen within the figure, the blending of lanolin is 2900cm-1wavenumber.

Abbildung in dieser Leseprobe nicht enthalten

Figure 8: FT-IR graph of sample 3. a) pure SA, b) sample 3, d) integration of lanolin. (authors own work)

2.2.2 Antibacterial Essay Result

Determining the growth inhibition zone of wound dressing is proper. Lanolin has antifungal and antibacterial activity. Lanolin has the same chemical composition as human skin 10. This study showed that lanolin has antibacterial activity. It was compared with the ampicillin zone and Escherichia coli was used. The disk diffusion method was used.

Abbildung in dieser Leseprobe nicht enthalten

Figure 9: İnhibition zone graph. (authors own work)

2.2.3 Swelling Analysis of Scaffolds

The swelling capacity of scaffolds is decided by the quantity of liquid material absorbed by them. The equilibrium swelling capacity of hydrogels may be a balance between swelling and elastic forces. Therefore the proper design of swelling parameters allows for hydrogel scaffolds to regulate the diffusion of bioactive molecules and migration of cells through the complex network structure 11. Second-degree burns affect the skin, called the dermis. The two most vital problems encountered clinically with burned patients are infection and dehydration. When an individual is burned and depending on the severity of the burn, the blood vessels, including the capillaries, could also be affected. Combined with the discharge of chemicals into the blood, this may increase capillary permeability to fluids, resulting in the leaking of fluids from the blood vessels into the tissues. The upper the share of burned skin, the more severe the loss of fluid is going to be and therefore, the greater dehydration will directly affect the skin 12. Moist-providing wound dressings are suitable for second-degree burn wounds. The sort controls the total absorbency and swelling capacity and degree of cross-linkers want to make a gel. The highly cross-linked polymer exhibits low absorption capacity, but the low cross-linked polymer dissolves within the liquid. Therefore, optimum cross-linkers are required to develop SAPs in order that they show high absorption capacity 13. During this study, a 1% salt dehydrate solution was used as a crosslinker.

Alginates provide many benefits to be used as wound dressings: they swell and retain large amounts of water (100% to over 1000% of their dry mass), thus providing an optimal moist environment; the act of swelling and diffusion throughout the gel allows the wound exudates to be absorbed, which, in turn, accelerates healing; and, due to the wet structure, the dressing doesn't stick with the wound bed and cause secondary trauma upon removal. The alginate dressing is often applied either pre-wetted to provide a desiccated wound with moisture, or dry, to assist within the absorption of exudates 13. During this study, the swelling behavior of samples 1, 2, 3, 4, 5 and 6 were analyzed. Lanolin percentage in sodium alginate solution increases the swelling ratio of scaffolds increases. The minimum ratio of swelling was found in sample 2 and the maximum swelling ratio was found in sample 6. This shows that when animal oil solution enters in alginate solution, swelling changes towards the ratio of animal oil. It is surprising that, as a result, the animal oil addition within the structure increases the water capacity of the alginate wound dressing.

Figure 10 : The swelling graph of samples. (authors own work)

2.2.4 Degradation Analysis of Scaffolds

Degradation percentage is critical for burn wound healing and for the preservation of burn wounds. The wound dressing may be a physical barrier to prevent physical damage to the wound. Burn wounds are dynamic and alter in appearance, particularly within the first 48 hours (1728*102s). Therefore, it's the practice of the burn services to review burns after 48 hours (1728*102s) before decisions regarding definitive dressings or surgery are made. The initial burn dressing should be one that will remain intact for 48 hours (1728*102s) and stop infection. It's a protocol within the burn service to decorate all burns with dressing for 48 hours (1728*102s) 5. Therefore, degradation percentage is vital in 48hours (1728*102s). During this study, degradation tests were administered in appropriate time intervals; degradation wasn't visible and memorable. This guarantees the power of this layer to hide and preserve the burnt area until reaching crucial healing. At 72 hours (2592*102s), degradation was visible. The very best degradation percentage was in sample 6 at the appropriate interval. The minimum degradation percentage was observed in sample 1 appropriate interval. Therefore, animal oil solution affects degradation percentage; consequently, as animal oil solution concentration increases, degradation percentage increases. In sample1, degradation was also observed. This might be explained by the presence of alginate as an elementary material in both hydrogels, which contained Ca2+ ions. When alginate-based hydrogels were immersed in PBS media containing monovalent ions like Na+, these ions could compete with original Ca2+ ions and begin to degrade the hydrogels over time thanks to a natural process reaction between Ca2+ ions and Na+ ions 14. Eventually, the low degradation behavior of samples made the prepared designed scaffolds ideal in enhancing burn wound healing.

Abbildung in dieser Leseprobe nicht enthalten

Figure 11: Degradation pattern of samples. (authors own work)

2.2.5 pH Analysis of Scaffolds

Wound healing may be a difficult period. The pH value within the wound milieu, directly and indirectly, influences all biochemical reactions happening within wound healing. It has been proven that the surface pH of a wound plays a crucial role in wound healing because it helps control infection and increase antimicrobial activity, oxygen release, and bacterial toxicity. Therefore, pH value affects the regular cellular events in wound healing. The previous study was shown that an acidic environment created by the use of acids, algin, ethanoic acid, boric acid, vitamin C, and mucopolysaccharide help in wound healing by controlling wound infection, increasing antimicrobial activity, altering protease activity, releasing oxygen, reducing the toxicity of bacterial end products, and enhancing epithelization and angiogenesis 15.

In pure water, the concentrations of H3O+ and OH- are equal. However, when acid and base are added to water, the H3O+ and OH- ions are not any longer present in equal amounts. By comparing the values of H3O+ and OH-, pH are often determined 16. In this study, pH values were primarily stable. The pH value of the solution, with no dressing (control), ranged from 5.38 to 6.25 over the 7-day period, with a mean of 5.81. This shows that samples decreased pH of the control solution. The pH Changes of all samples was observed on the 4th, 5th and 6th day. The sample degradation wasn't marked at a temperature in two of pH measurement solutions. Thereby, the dressing wasn't dissolved in solution and ion change did not occur and these changes aren't remarkable. The pH range of solutions was 5.38 to 5.08. The solutions are acidic and suitable for burn wound healing.

Abbildung in dieser Leseprobe nicht enthalten

Figure 12: The pH graph of samples. a) sample 1, b) sample 2, c) sample 3, d) sample 4 e) sample 5 f) sample 6. (authors own work)

2.2.6 Paper Chromatography

The paper chromatography method is employed to separate mixtures into individual substances. It is utilized in the process to separate substances and determine the quality of drugs. Vitamins, preservatives, amino acids, proteins are analyzed by chromatography. Also, detection of alcohol in the blood is often done by using chromatography 17. During this study, diffusion distances were measured and calculated. As seen in figure 10, diffusion distances are increasing in 4 hours(144*102s). After 4 hours (144*102s), oscillation has proceeded and distance is stabilized.

Abbildung in dieser Leseprobe nicht enthalten

Figure 13: Distance vs. time graph of oscillation. (authors own work)

2.2.7 Microscopy

Microscopy is employed to magnify small objects. During this study, the microscope is employed to define how lanoline concentrations affect the structure of wound dressings. As seen in figure 11, we can observe as oil concentrations increase, the visibility of the cell membrane increases. As oil concentration is increased, the pore size increases.

Abbildung in dieser Leseprobe nicht enthalten

Figure 11: microscope pictures of samples. a) sample 1 b) sample 2 c) sample 3 d) sample 4 e) sample 5 f) sample 6. As seen in the figure, as oil concentrations increase, the visibility of the cell wall increased. (authors own work)

Abbildung in dieser Leseprobe nicht enthalten

Figure 14: Photographs of scaffolds. (authors own work)

Abbildung in dieser Leseprobe nicht enthalten

Figure 15: Table of concentrations. (authors own work)

Conclusion

In conclusion, lanolin is a widely used substance in pharmacy. Also, animal grease is used in history to protect the wound from the environment. Wool oil concentration is crucial for wound dressing due to 3D printability and healing criteria. In this study, the scaffold was designed to be inspired by a twill textile structure using Adobe Fusion 360 3D drawing program and many tests have been done. These tests are Fourier Transform-Infrared Spectroscopy (FT-IR), antibacterial essay, swelling, degradation, pH, paper chromatography and microscopy analysis. Fourier Transform-Infrared Spectroscopy (FT-IR) result showed that modification of lanolin had done successfully. Antibacterial assay results showed that lanolin has an antibacterial property. Swelling tests and degradation tests showed that as wool oil concentration increased, swelling and degradation is increased. pH analysis showed that there is no notable change as oil concentration is increased. Paper Chromatography results showed that wound dressing has oscillation. Microscopy analysis showed that as wool oil concentration is increased, the visibility of the cell wall is increased. All experiments were repeated 3 times; all statistical analysis was done using R studio. Due to 3D printing difficulty, more than 5% concentration of wool oil is not appropriate for manufacturing.

References

1 What Are the Types and Degrees of Burns?, (n.d.). https://www.webmd.com/first-aid/types-degrees-burns#1 (accessed January 10, 2021).
2 V.K. Tiwari, Burn wound: How it differs from other wounds, Indian Journal of Plastic Surgery. 45 (2012). https://doi.org/10.4103/0970-0358.101319.
3 Burns, (n.d.). https://www.who.int/news-room/fact-sheets/detail/burns (accessed January 10, 2021).
4 History of wound care - Wikipedia, (n.d.). https://en.wikipedia.org/wiki/History_of_wound_care (accessed January 10, 2021).
5 H.E. Douglas, F. Wood, Burns dressings, Australian Family Physician. 46 (2017).
6 C.B. Williams, C.C. Seepersad, Design for additive manufacturing curriculum: A problem- and project-based approach, in: 23rd Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2012, 2012.
7 M. Chvapil, J.A. Gaines, T. Gilman, Lanolin and epidermal growth factor in healing of partial-thickness pig wounds, Journal of Burn Care and Rehabilitation. 9 (1988). https://doi.org/10.1097/00004630-198805000-00009.
8 C. Mariani Neto, R.S. de Albuquerque, S.C. de Souza, R.O. Giesta, A.P.S. Fernandes, B. Mondin, Comparative Study of the Use of HPA Lanolin and Breast Milk for Treating Pain Associated with Nipple Trauma, Revista Brasileira de Ginecologia e Obstetricia. 40 (2018). https://doi.org/10.1055/s-0038-1675180.
9 Twill - Wikipedia, (n.d.). https://en.wikipedia.org/wiki/Twill (accessed January 10, 2021).
10 Lanolin, Wool and Hand Cream - OpenLearn - Open University, (n.d.). https://www.open.edu/openlearn/science-maths-technology/science/chemistry/lanolin-wool-and-hand-cream (accessed January 14, 2021).
11 J. Zhu, R.E. Marchant, Design properties of hydrogel tissue-engineering scaffolds, Expert Review of Medical Devices. 8 (2011). https://doi.org/10.1586/erd.11.27.
12 Third Degree Burns and Dehydration — Burn Injury Resource Center — September 13, 2011, (n.d.). https://www.burn-injury-resource-center.com/third-degree-burns-and-dehydra/ (accessed January 10, 2021).
13 Advanced Textiles for Wound Care - Google Kitaplar, (n.d.). https://books.google.com.tr/books?hl=tr&lr=&id=za1vDwAAQBAJ&oi=fnd&pg=PP1&dq=advances+textiles+for+wound+care&ots=_YE_rFd22n&sig=hlw9ft_TCwKgejEO-S9EEPmU_Uk&redir_esc=y#v=onepage&q=advances%20textiles%20for%20wound%20care&f=false (accessed January 13, 2021).
14 S. Droge, K.U. Goss, Effect of sodium and calcium cations on the ion-exchange affinity of organic cations for soil organic matter, Environmental Science and Technology. 46 (2012). https://doi.org/10.1021/es204449r.
15 B.S. Nagoba, N.M. Suryawanshi, B. Wadher, S. Selkar, Acidic environment and wound healing: A review, Wounds. 27 (2015).
16 General Chemistry: Principles and Modern Applications - Ralph H. Petrucci, F. Geoffrey Herring, Jeffry D. Madura, Carey Bissonnette - Google Kitaplar, n.d. https://books.google.com.tr/books?id=E1CTDAAAQBAJ&dq=petrucci+general+chemistry+11th+edition&hl=tr&sa=X&ved=2ahUKEwi0x_Gt4pnuAhVNxosKHVLeCLEQ6AEwAHoECAEQAg (accessed January 13, 2021).
17 How Is Chromatography Used in Industry?, (n.d.). https://www.reference.com/science/chromatography-used-industry-b7e19024479dc99b (accessed January 10, 2021).

[...]