Petra Rantanen Poster
2
Petra Rantanen, under the supervision of Dr. Rashid Bashir and Matthew Alonso University Laboratory High School and the College of Engineering, Department of Electrical and Computer Engineering/Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign Using Stereolithography to Create Artificial Skin Acknowledgments I greatly appreciate the help and supervision of Dr. Rashid Bashir, Matt Alonso, Mitch Collins, and Vincent Chan, as well as Dr. Lizanne Destefano, ―Ray‖ Carrubba, and the other Uni High faculty involved in this program. What I Learned Through the I-STEM program, I gained exposure to lab practices and business etiquette, and I became more proficient in reading research articles. I also learned much about skin and stereolithography. I am very grateful that I had the opportunity to participate in the experience. Aim The aim of this project is to create artificial skin by using stereolithograph y methods. This could be used to treat burn victims. Importance Skin is extremely important as it serves many functions: • Protection against infection • Thermoregulation • Storage of water, fat, and vitamin D • Sense Current Methods for Burn Treatment • Skin grafts: healthy skin is taken from ―donor site‖ such as inner thigh or cadaver and placed over wound. Disadvantages: damaged donor site, or immune system rejects skin from cadaver shortly after the operation. • Composite Cultured Skin (CCS): skin from healthy donors is cultured and seeded on a collagen sponge. CCS includes growth factors so the patient‘s own skin grows over transplant. • There are various other option s, all with their own advantages and disadvantage s. This project would aim to reduce many of those disadvantages. Introduction • Stereolithography , a type of 3D printing, is a method of creating 3-dimensional objects from 2-dimensional cross- sections. • It has distinct advantages in modeling and rapid prototyping and is often used in medical applications. • Researchers are currently pioneering the use of stereolithograph y to create artificial tissues. • I want to use this t echnology to create artificial skin. Stereolithog raphy Apparatus (SLA) • The SLA at the Micro and Nanotechnology Laboratory (MNTL) uses direct writing,, where a UV laser selectively hardens the polymer. • A recent study showed that cells can live longer when they are pre-mixed with the polymer and then arranged in their own layers. • The computer model of the scaffold is created using AutoCAD. The image on the right is a scaffold design I made that could be used for artificial skin. Each band is .1 mm thick. Projection Stereolithogr aphy • This is different from direct writing because the whole image is projected onto the polymer, as opposed to one line being drawn at a time. • The cross section is created on the computer using Microsoft Powerpoint. • The image is then transferred onto the chip (DMD). The chip consists of many mirrors, which are either on or off. The ‗on‘ mirrors show the image. • The image on the DMD is then projected, using UV light, and focused onto the polymer, which cures due to the light. • This technique is still being developed to demonstrate micropatterning of cells. Proposal Concept • The skin would preferably be biodegradable so that the patient‘s own skin cells could eventually replace the artificial skin. • It would be difficult to make all three layers of the skin. However , artificial skin that included all three layers would be more useful. • There are two basic approaches : (1) create the scaffold so that the patient‘s cells will grow into it, or (2) create the scaffold with the cells already in it. Skin Anatomy There are three different layers of skin: the epidermis (.04- .15 mm thick), the dermis (~1.1 mm thick), and the subcutis (~1.2 mm thick). These are all components of skin that could be necessary, espec ially if the artificial skin would already have cells: • Keratinocytes —flattened cells which produces the protein keratin, which is the main constituent of skin. • Basal cells—cells that form keratinocytes. • Melanocytes—cells that produce melanin, or pigment. • Lagerhans cells—cells concerned with immune system. • Merkel cells—cells concerned with fine touch. • Basement membrane zone (BMZ)—connects epidermis and dermis. This area is important in burn healing as it provides protection from shearing. • Blood vessels—thermoregulation, nutrient transport • Lymph vessels—supply lymph to fight microbes. • Hair follicles—insulation, also sense • Sweat glands—thermoregulation • Fibroblasts-make collagen • Pain/touch receptors • Elastic fibers • Glycosaminoglycans (GAGs) and adhesion molecules — binding to, releasing, and neutralizing cytokines and growth factors. • Collagen –connective tissue, provides support. • Fat cells—provide insulation Materials • We would need a material that is somewhat permeable to water and facilitates gas exchange. It would also need to be as strong as regular skin so it would not easily be punctured. • Stiffness and porosity of skin would also need to be researched experimentally. • If cells were to be encapsulated in the scaffold before the skin was attached to the patient, the cells would need to be the patient‘s own cells so that the immune system would not reject the artificial skin. References Alonso, M. P. (2010). Optimization of a light emitting diode based projection stereolithography system and its applications. Retrieved from https://www.ideals.illinois.edu/bitstream/handle/ 2142/16160/1_Alonso_Matthew.pdf?sequence=2 Chan, V., Zorlutuna, P., Jeong, J. H., Kong, H., & Bashir, R. (2010). Three- dimensional photopatter ning of hydrogels using stereolithography for long-term cell encapsulat ion. Lab on a Chip, 10, 2062-2070. doi:10.1039/c0 04285d Dermatology: Anatomy of the skin. (2008, February 19). Retrieved June 20, 2011, from University of Maryland Medical Center website: http://www.umm.edu/dermatology-info/anatomy.htm Hendriks, F. M., Brokken, D., Oomens, C. W. J., Baaijens, F. P. T., & Horsten, J. B. A. M. (2000). Mechanical proper ties of different layers of human skin. Retrieved from Eindhoven University of T echnology website: http://www.mate.tue.nl/mate/pdfs/249.pdf Skin graft--overview. (n.d.). Retrieved June 20, 2011, from University of Maryland Medical Center website: http://www.umm.edu/ency/article/002982.htm Sterling, J. P., Heimbach, D. M., & Gibran, N. S. (2010). Management of the burn wound. In W. W. Souba & D. W. Wilmore (Eds.), ACS surgery: Princip les and practice.Retrievedfrom http://www.ucdenver.edu/academics/colleges/medicalschool/departments/surgery/di visions/GITES/burn/Documents/Management%20of%20the%20Burn%20Wound.pdf Technology To create the artificial skin, we would use stereolithography. There are different types of stereolithograph y systems, but each has the same basic principle: a computer slices the 3D digital model into cross sections. Each layer is then patterned one at a time onto a polymer by ultraviolet (UV) light, which cures the polymer. Then more uncured polymer is placed on top and the process repeats. One challenge in tissue engineering using stereolithography is determining the best way to encapsula te cells in the scaffold (structure). To make artificial skin, we would need to do this. Image sources: http://www.nlm.nih.gov/medlineplus/ magazine/issues/fall08/images/skin_ replacement.jpg http://www.med.umich.edu/histology/ fieldTrip/skinMedMag.jpg
Transcript of Petra Rantanen Poster
8/4/2019 Petra Rantanen Poster
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Petra Rantanen, under the supervision of Dr. Rashid Bashir and Matthew AlonsoUniversity Laboratory High School and the College of Engineering, Department of Electrical and Computer Engineering/Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign
Using Stereolithography to Create Artificial Skin
Acknowledgments
I greatly appreciate the help and supervision of Dr. RashidBashir, Matt Alonso, Mitch Collins, and Vincent Chan, aswell as Dr. Lizanne Destefano, ―Ray‖ Carrubba, and theother Uni High faculty involved in this program.
What I Learned
Through the I-STEMprogram, I gainedexposure to lab practicesand business etiquette,and I became moreproficient in reading
research articles. I alsolearned much about skinand stereolithography. I amvery grateful that I hadthe opportunity toparticipate in theexperience.
Aim
The aim of this project is to create artificial skin by usingstereolithography methods. This could be used to treat burnvictims.
Importance
Skin is extremely important as it serves many functions:
• Protection against infection• Thermoregulation
• Storage of water, fat, and vitamin D
• Sense
Current Methods for Burn Treatment
• Skin grafts: healthy skinis taken from ―donor site‖
such as inner thigh orcadaver and placed overwound. Disadvantages:damaged donor site, orimmune system rejectsskin from cadaver shortlyafter the operation.
• Composite Cultured Skin (CCS): skin from healthy donorsis cultured and seeded on a collagen sponge. CCS
includes growth factors so the patient‘s own skin growsover transplant.
• There are various other options, all with their ownadvantages and disadvantages. This project would aim toreduce many of those disadvantages.
Introduction
• Stereolithography, a type of 3D printing, is a method ofcreating 3-dimensional objects from 2-dimensional cross-sections.
• It has distinct advantages in modeling and rapidprototyping and is often used in medical applications.
• Researchers are currently pioneering the use ofstereolithography to create artificial tissues.
• I want to use this t echnology to create artificial skin.
Stereolithography Apparatus (SLA)
• The SLA at the Micro andNanotechnology Laboratory(MNTL) uses direct writing,,where a UV laser selectivelyhardens the polymer.
• A recent study showedthat cells can live longerwhen they are pre-mixedwith the polymer and thenarranged in their own layers.
• The computer model of thescaffold is created usingAutoCAD. The image on theright is a scaffold design Imade that could be usedfor artificial skin. Each band is .1 mm thick.
Projection Stereolithography
• This is different from direct writing because the whole
image is projected onto the polymer, as opposed to oneline being drawn at a time.
• The cross section iscreated on the computerusing Microsoft Powerpoint.
• The image is then transferredonto the chip (DMD). The chipconsists of many mirrors,which are either on or off. The‗on‘ mirrors show the image.
• The image on the DMD isthen projected, using UVlight, and focused onto thepolymer, which cures dueto the light.
• This technique is still beingdeveloped to demonstratemicropatterning of cells.
Proposal
Concept
• The skin would preferably be biodegradable so that the
patient‘s own skin cells could eventually replace theartificial skin.
• It would be difficult to make all three layers of the skin.However, artificial skin that included all three layers wouldbe more useful.
• There are two basic approaches: (1) create the scaffold sothat the patient‘s cells will grow into it, or (2) create thescaffold with the cells already in it.
Skin Anatomy
There are three different layers of skin: the epidermis (.04-.15 mm thick), the dermis (~1.1 mm thick), and the subcutis(~1.2 mm thick). These are all components of skin thatcould be necessary, especially if the artificial skin wouldalready have cells:
• Keratinocytes—flattened cells which produces the proteinkeratin, which is the main constituent of skin.
• Basal cells—cells that form keratinocytes. • Melanocytes—cells that produce melanin, or pigment.
• Lagerhans cells—cells concerned with immune system.
• Merkel cells—cells concerned with fine touch.
• Basement membrane zone (BMZ)—connects epidermisand dermis. This area is important in burn healing as itprovides protection from shearing.
• Blood vessels—thermoregulation, nutrient transport
• Lymph vessels—supply lymph to fight microbes.
• Hair follicles—insulation, also sense
• Sweat glands—thermoregulation
• Fibroblasts-make collagen
• Pain/touch receptors
• Elastic fibers
• Glycosaminoglycans (GAGs) and adhesion molecules—binding to, releasing, and neutralizing cytokines andgrowth factors.
• Collagen –connective tissue, provides support.
• Fat cells—provide insulation
Materials
• We would need a material that is somewhat permeable to water and facilitates gas exchange. It would also needto be as strong as regular skin so it would not easily bepunctured.
• Stiffness and porosity of skin would also need to beresearched experimentally.
• If cells were to be encapsulated in the scaffold before theskin was attached to the patient, the cells would need tobe the patient‘s own cells so that the immune system
would not reject the artificial skin.
References
Alonso, M. P. (2010). Optimization of a light emitting diode based projectionstereolithography system and its applications. Retrieved fromhttps://www.ideals.illinois.edu/bitstream/handle/ 2142/16160/1_Alonso_Matthew.pdf?sequence=2
Chan, V., Zorlutuna, P., Jeong, J. H., Kong, H., & Bashir, R. (2010). Three-dimensional photopatterning of hydrogels using stereolithography for long-term cellencapsulation. Lab on a Chip, 10, 2062-2070. doi:10.1039/c004285d
Dermatology: Anatomy of the skin. (2008, February 19). Retrieved June 20, 2011,from University of Maryland Medical Center website:http://www.umm.edu/dermatology-info/anatomy.htm
Hendriks, F. M., Brokken, D., Oomens, C. W. J., Baaijens, F. P. T., & Horsten, J. B. A.M. (2000). Mechanical proper ties of different layers of human skin. Retrieved fromEindhoven University of Technology website:http://www.mate.tue.nl/mate/pdfs/249.pdf
Skin graft--overview. (n.d.). Retrieved June 20, 2011, from University of MarylandMedical Center website: http://www.umm.edu/ency/article/002982.htm
Sterling, J. P., Heimbach, D. M., & Gibran, N. S. (2010). Management of the burn
wound. In W. W. Souba & D. W. Wilmore (Eds.), ACS surgery: Princip les andpractice. Retrieved fromhttp://www.ucdenver.edu/academics/colleges/medicalschool/departments/surgery/divisions/GITES/burn/Documents/Management%20of%20the%20Burn%20Wound.pdf
Technology
To create the artificial skin, we would use stereolithography.There are different types of stereolithography systems, buteach has the same basic principle: a computer slices the 3Ddigital model into cross sections. Each layer is thenpatterned one at a time onto a polymer by ultraviolet (UV)light, which cures the polymer. Then more uncured polymeris placed on top and the process repeats. One challenge in
tissue engineering using stereolithography is determiningthe best way to encapsulate cells in the scaffold(structure). To make artificial skin, we would need to do this.
Image sources:http://www.nlm.nih.gov/medlineplus/ magazine/issues/fall08/images/skin_ replacement.jpghttp://www.med.umich.edu/histology/ fieldTrip/skinMedMag.jpg
