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ARTIFICIAL SKIN AND ARTIFICIAL CARTILAGE

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The term artificial skin is used to describe any material used to replace (permanently or temporarily) or to mimic the dermal and epidermal layers of the skin. The primary current application of artificial skin is for the treatment of skin loss or damage on burn patients. Alternatively however, artificial skin is now being used in some places to treat patients with skin diseases, such as diabetic foot ulcers, and severe . – PowerPoint PPT presentation

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Title: ARTIFICIAL SKIN AND ARTIFICIAL CARTILAGE


1
ARTIFICIAL SKIN
PRESENTED BY
PWADUBASAHIYI COSTON PWAVODI 20143883 MSC. FELIX
CHIBUZO OBI 20144610 MSC. MICHAEL OLABOYE AMUSAN
20103181 ARTIFICIAL ORGANS DEPARTMENT OF
BIOMEDICAL ENGINEERING..
2
INTRODUCTION
  • The term artificial skin is used to describe any
    material used to replace (permanently or
    temporarily) or to mimic the dermal and epidermal
    layers of the skin.
  • The primary current application of artificial
    skin is for the treatment of skin loss or damage
    on burn patients.
  • Alternatively however, artificial skin is now
    being used in some places to treat patients with
    skin diseases, such as diabetic foot ulcers, and
    severe .1

3
ANATOMICAL OVERVIEW OF THE SKIN
  • Human skin is comprised of two primary layers,
    the dermis and the epidermis. A diagram of a
    typical section of human skin is shown here. The
    epidermis is comprised of keratinocytes of
    varying levels of differentiation.
  • As can be seen in the figure, the epidermis
    contains no blood vessels meaning transport of
    nutrients to the epidermis occurs from the dermis
    below 2.

4
BRIEF HISTORY OF THE ARTIFICIAL SKIN
  • 3000-2500BC, India Skin is allegedly
    transplanted by Hindus from the buttocks to
    repair mutilated ears and noses.
  • 1442, Italy An allogenous skin graft was
    performed by Branca de Branca who used a mans
    arm skin to transplant the nose of the mans
    slave onto himself.
  • 1871, England Pollock proposes skin grafts for
    burn treatment.
  • 1998, United States First tissue engineered skin
    (Apligraf) is approved by the FDA.
  • 2001, United States Dermagraft, Orcel, Composite
    Cultured Skin are FDA approved 4.
  • 2002, United States Integra is FDA approved for
    treatment of severe burns 4.

5
PROCESSES INVOLVED IN THE MANUFACTURE OF THE
ARTIFICIAL SKIN
  • Skin is usually donated by other donors.
  • Fibroblasts are removed from the donated skin and
    are frozen until they are needed.
  • The fibroblasts are placed on a polymeric mesh
    scaffolding, gather oxygen, and grow new cells.
  • The cells are then transferred to a culture
    system.After 4 weeks the polymer mesh dissolves
    and leaves behind a new layer of dermal skin.
  • When the growth cycle is completed, they add more
    nutrients. Keratinocytes are added to the
    collagen and are exposed to air to form
    epidermal layers.
  • The skin is now completed and is stored in
    sterile contains until ready to use.

6
  • Skin Grafts
  • Skin grafts are required for patients with skin
    damage that is too significant for self-repair.
    As stated before, one of the primary requirements
    for artificial skin is for the treatment of
    severe burn victims. 2
  • Skin grafts are also often done on patients with
    ulcers, skin loss from cancer removal, and
    plastic surgery 1
  • The skin required for a skin graft can be
    obtained from three sources the patient
    themselves (autograft), another human
    (allograft), or from animals such as pigs or cows
    (xenografts)2. Allografts and xenografts can
    only be used as temporary wound coverings as they
    are typically rejected within 7 to 10 days or 3
    to 5 days respectively 2.

7
  • Artificial Skin Treatments
  • Since 2001, a total of 4 skin repair devices have
    been FDA approved. These include Dermagraf,
    Orcel, Integra, and Composite Cultured Skin 4.
    Composite Cultured Skin is specifically for
    children with recessive dystrophic epidermolysis
    bullosa and also contain living cells.

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9
AREAS OF APPLICATION
  • Artificial Skins are primarily used for the
    Treatment of Skin loss or damage on burn
    Patients. Alternative Areas of Application of
    Artificial Skins includes
  • -Treatment of patients with skin diseases, such
    as diabetic foot ulcers, and severe scarring.
  • - Plastics and Cosmetic Surgery.

10
ADVANTAGES AND DISADVANTAGES
  • ADVANTAGES
  • -Chances of survival for burn patients.
  • -Artificial skin seals the wound preventing fluid
    loss and bacteria from entering through the
    wound.
  • - The fear of Stigmatization of the Patient is
    eliminated
  • DISADVANTAGES
  • -Risks of Infection and Rejection by the Patients
  • -Lack of vascularization to the implanted skin or
    skin cells can lead to cell death which provides
    a breeding ground for bacteria.
  • -Loss of Sensitivity
  • -Cut of Blood Supply.
  • -Complication could arise due to Skin Adhesion
    and/or fluid buildup between the wounded site and
    the transplanted skin.
  • - Artificial Skins are very expensive.

11
RECENT DEVELOPMENTS OF THE ARTIFICIAL
SKIN/ONGOING RESEARCH
  • Though artificial skin has aided significantly in
    skin regeneration, there remain several areas for
    improvement. Ongoing Research attempt to produce
    bacteria-resistant skin cell cultures that can be
    used in artificial skin. Ideally, this would
    allow in vitro replication of a patients own
    genetically modified skin cells. These cells
    could then be put into the artificial matrix for
    bacteria-free growth.
  • Another current trend in Artificial is the
    creation of Electronic Skin. Scientist are
    working towards the Incorporation of flexible
    pressure transducers and Bioreceptors to the
    Artificial Skin, these will give a sense of Touch
    to the Patients.
  • Outside of artificial biological skin, synthetic
    skin is being developed in hopes of enabling the
    sensation of touch to non-living structures.
    Flexible pressure transducers may eventually
    allow us to create an electronic skin with
    signals to mimic the sense of touch. This has
    applications in robotics including advanced
    prosthetic limbs 8.

12
RECENT DEVELOPMENTS OF THE ARTIFICIAL
SKIN/ONGOING RESEARCH
  • Other advances have been made in the application
    of cells to the matrices. Dr. Fiona Woods has
    produced a spray on skin called Cellspray. This
    method takes healthy cells from the patient and
    creates a suspension culture of the cells. The
    cells are then distributed by spraying them
    evenly across the matrix. It is believed that
    this method will be beneficial because the
    suspension cell culture can be produced much
    faster (5 days) than traditional methods which
    require formation of a sheet of cells (21 days).
    Though this procedure has not been through
    clinical trials, it was controversially used on
    burn victims in conjunction with traditional
    methods in the Bali bombings in 2004. Further
    testing is required before this treatment can
    officially be deemed successful.

13
CONCLUSION
  • The ultimate goals of current artificial skin
    technologies are to provide protection from
    infection, dehydration, and protein loss after
    severe skin loss or damage.

14
REFERENCES
  • 1 Dantzer, E., Queruel, P., Salinier, L.,
    Palmier, B., Quinot, J. F. (2001). Integra, a
    new surgical alternative for the treatment of
    massive burns. Clinical evaluation of acute and
    reconstructive surgery 39 case. Annales De
    Chirurgie Plastique Esthétique, 46(3), 173-189.
    http//www.ncbi.nlm.nih.gov/pubmed/11447623
  • 2 Roos, D. (2012). Skin grafts. Retrieved
    02/29, 2012, from http//health.howstuffworks.com/
    skin-care/information/anatomy/skin-graft.htm
  • 3 Heman, A. R. (2002). The history of skin
    grafts. Retrieved 02/29, 2012, from
    http//findarticles.com/p/articles/mi_m0PDG/is_3_1
    /ai_110220336/

15
ARTIFICIAL CARTILAGE
16
INTRODUCTION
  • Articular cartilage is a highly organized
    avascular tissue composed of chondrocytes
    embedded within an extracellular matrix of
    collagens, proteoglycans and noncollagenous
    proteins. Its primary function is to enable the
    smooth articulation of joint surfaces, and to
    cushion compressive, tensile and shearing forces.
    Hyaline cartilage has one of the lowest
    coefficients of friction known for any surface to
    surface contact. 
  • Cartilage is unique as it is an avascular,
    aneural tissue, in which cells survive for a
    lifetime, without intercellular connections.Owing
    to its sophisticated composition, its high water
    content and its ability to withstand hydrostatic
    pressurization, cartilage is capable of
    transferring enormous forces relatively evenly
    from one subchondral bone plate to the other.

17
OVERVIEW OF THE ANATOMY OF THE CARTILAGE
  • Cartilage is a flexible connective tissue found
    in many areas in the bodies of humans and other
    animals, including the joints between bones, the
    rib cage, the ear, the nose, the bronchial tubes
    and the intervertebral discs. It is not as hard
    and rigid as bone but is stiffer and less
    flexible than muscle.
  • ARTICULAR CARTILAGE?
  • Hyaline articular cartilage is a complex
    structure, developed and progressively refined
    over hundreds of millions of years. Articular
    cartilage provides smooth articulation under
    variable loads and impaction for very long
    periods of time. It serves as the load-bearing
    material of joints, which has excellent friction,
    lubrication and wear characteristics. The
    cartilage thickness varies significantly across
    articular surfaces of the same joint. Normal
    hyaline cartilage has a glossy, bluish white,
    homogenous appearance, firm consistency and some
    elasticity. .

18
  • Cells called chondrocytes
  • Abundant extracellular matrix
  • Fibers collagen elastin
  • Jellylike ground substance of complex sugar
    molecules
  • 60-80 water (responsible for the resilience)
  • No nerves or vessels

19
BRIEF HISTORY OF THE ARTIFICIAL CARTILAGE
  • The history up to 1900 is told chronologically,
    divided into (1) recognition of the tissue, (2)
    structure, and (3) chemistry. The twentieth
    century is sketched with a timeline of
    discoveries that at the time were important and a
    bibliography of journal review articles.
  • By 1900 the avascular, aneural state and
    fibrillar composition have been accepted. The
    nutrition of articular cartilage remained in
    dispute. The composition of the binding substance
    and its relation to collagen remained unknown.
    Research in the first half of the twentieth
    century continued to be impeded by lack of
    technology. The advent of electron microscopy,
    isotopic tracer technics and enzymology rapidly
    accelerated the understanding of hyaline
    cartilage beginning in the 1950s.

20
MANUFACTURING PROCESSES
  • Unique building block of articular cartilage
    matrix is Type II collagen
  • Middle architectural zone called the netting is
    made of aggregates of proteoglycans called
    glycosamino- glycans (GAGs) This netting holds
    water i.e. gives this zone its hydrophilic
    character that yields the low friction, fluid
    wave enabling smooth joint motion

21
  • Restore smooth articular cartilage surface
  • Relieve patient symptoms and improve function
  • Match biomechanical/biochemical properties of
    normal hyaline cartilage
  • Prevent or slow progression of focal chondral
    injury to end- stage arthritis
  • Scaffolds to enhance Micr0-fx marrow cell
    stimulation
  • 2nd Generation Cell Techniques
  • Minced Cartilage ( One stage techniques)
  • 3rd Generation cell techniques
  • Concurrent Use of Growth factors/ BMPs
  • Enhanced Stem cell derived

22
Scaffolds
  • Region-specific
  • Conductive several substrates
  • Including chitosan/ fibrinogen
  • Bio-replaced
  • Cost-effective
  • May act as Micro-fx adjunct
  • ie Scaffold guided regeneration

23
2nd Generation Cell Therapies
  • Autogenous cells
  • Seeded scaffold or liquid gel
  • Minimizes periosteal related complications
  • Allows arthroscopic implant

24
3rd Generation Cell Based
  • Autogenous
  • Allogeneic
  • 3-D Cartilage graft
  • Technical ease might allow
  • arthroscopic insertion with
  • bioadhesive

25
Other 3rd Generation Potential Enhancements
  • Expanded Juvenile chondrocytes
  • Scaffold independent cx
  • Clinical Phase I completed
  • FDA Phase II/III IND/BLA pending

Sheep Allograft 8 Weeks
Juvenile Cartilage
Adult Cartilage
26
CURRENT TRENDS/RESENT DEVELOPMENT OF THE
ARTIFICIAL CARTILAGE
  • A resent development of the Artificial Cartilage
    is it use in the treatment of knee Injury.
    Studies have shown that almost half of all
    running injuries are knee injuries, tears could
    sometimes occur. For instance, Meniscus (the
    cartilage pad between the thigh and shin bones)
    tears can occur when a runner takes a misstep or
    twists, pivots or compresses the knee joint in
    the wrong way.
  • Biomedical Engineers are now able to implant
    Artificial Cartilage into patients knee that
    could restore much of the function to the damaged
    meniscus.
  • Another recent Application of the Artificial
    Cartilage is in Allograft Osteochongraph
    Transplantation (AOT). This is the process
    whereby the Cartilage is obtained from a recently
    deceased donor. It is then tested in the
    Laboratory to make sure it is free from Infection
    before been transplanted to the Patient.
  •  

27
ONGOING RESEARCH IN THE ARTIFICIAL CARTILAGES
  • A number of ongoing research projects are
    currently investigating more efficient and
    effective ways of repairing cartilage.
  • Examples of current research projects include
  • investigating ways of using different sources of
    stem cells to generate new cartilage (for
    example, bone marrow or fat)
  • using donor stem cells to regenerate cartilage
  • combining cartilage and stem cells to improve
    repair
  • Although these projects are still in the early
    stages, researchers are optimistic they will lead
    to new kinds of treatment.

28
AREAS OF APPLICATIONS OF THE ARTIFICIAL CARTILAGE
  • The Treatment of knee Injury
  • Articular Cartilage the smooth, white tissue
    that covers the ends of bones where they come
    together to form joints
  • Nose, Ear etc

29
ADVANTAGES OF THE ARTIFICIAL CARTILAGE.
  • It can protect runners from arthritis and total
    knee replacement
  • It can be use to correct birth defects
  • It brings hope and confidence to Patients
  •  
  • DISADVANTAGES OF THE ARTIFICIAL CARTILAGE
  • The Risk of complication and Infection
  • It could be rejected the patients body
  • Its expensive

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