Tissue Engineering Lecture 1 2024/2025 PDF

BME 2104 Tissue Engineering Lecture 1: Introduction of Tissue Engineering Dr. Ting-Hsuan Chen Semester A 2024/25 Tissue Engineering  Course Outline Lecture Schedule: Tuesday, 17:00 - 18:50, YEUNG P4701 (03 Sep) In...

BME 2104 Tissue Engineering Lecture 1: Introduction of Tissue Engineering Dr. Ting-Hsuan Chen Semester A 2024/25 Tissue Engineering  Course Outline Lecture Schedule: Tuesday, 17:00 - 18:50, YEUNG P4701 (03 Sep) Introduction of Tissue Engineering (10 Sep) Cell Source, Growth, and Differentiation (17 Sep) Morphogenesis (24 Sep) Cell Adhesion, ECM, and Chemotaxis (01 Oct) National Day (08 Oct) Mock Exam (15 Oct) Signaling and ECM (22 Oct) Mechanotransduction (29 Oct) Scaffold (05 Nov) Scaffold Fabrication (12 Nov) Bioreactor and Transplantation (19 Nov) Project Presentation 1 (26 Nov) Project Presentation 2 Semester A 2024/25 Tissue Engineering 2/49  Assessment pattern Date Due Grade Notes Individual Assignments Throughout term 15% presentation Lab Reports Throughout term 15% Group report Final Exam End of Term 50% Term Project Final weeks 20% Group of 5 Students Total 100% Semester A 2024/25 Tissue Engineering 3/49  Individual Presentation Friday, 16:00 - 17:50, YEUNG B4302 Each student is required to present one research paper during tutorial session in the semester. You should identify a paper of your interest. Ask me if you find difficult to find a suitable paper. The schedule was released on Canvas (subject to update after add-drop). The first presentation will be Sep 20, 2024. Please use the Discussion in Canvas to upload the paper you choose to present in the tutorial session. I have added some posts as examples. When posting, please indicate the date of your presentation in the content of your post, and use the attachment function to attach the PDF of the chosen paper. After the tutorial session, the presenting student is required to submit the presentation slide. Your assignment mark is determined by the presentation and organization of slides. Each presentation will be in 12 min presentation + 3 min Q&A Semester A 2024/25 Tissue Engineering 4/49  Lab Sessions Three labs will be conducted: – Cell Counting and Bio-imaging Major equipment: Confocal Microscope – Proliferation on ECM Substrate Major equipment: Spectrometer – Cell Differentiation Major equipment: Microplate Reader Location: P4810 Group report Lab report is due on the week after. Late report will be ungraded. Semester A 2024/25 Tissue Engineering 5/49  Term Project Projects may be on a topic chosen by each group of 5 students. The project will be literature review for the published literature of a specific topic related to the course. After a broad overview, you are requested to make comparison and choose to focus on one paper in the topic, and present the most important impact from that specific paper. Different from the paper presentation in the tutorial session, the term project targets a comprehensive study of the topic. The organization is suggested as – Introduction (Why it is important? Why it is needed in general population) – Literature review (What has been done?) – Key challenge (What has not been solved in the field?) – Potential solution (It will be that main point of the chosen paper) – Results supporting the idea – Your thought or idea (optional) – Conclusion Semester A 2024/25 Tissue Engineering 6/49  Project Presentation The marking scheme for the oral presentations is as follows: Presentation 25% Technical content 25% PowerPoint slides 25% Q&A 25% Total: 100% Each presentation will be in 12 min presentation + 3 min Q&A Semester A 2024/25 Tissue Engineering 7/49  Term Project Topic Report topics may be chosen from the list below. One topic can be chosen by at most two groups. First come first serve! Topics: – Heart – Skin – Bone – Nerve system – Blood vessel – Liver – Cartilage – Kidney – Bladder – Skeletal Muscle After register your group in Canvas, please notify me the topic by email. Semester A 2024/25 Tissue Engineering 8/49  Tissue Regeneration  Christopher Reeve  Actor of “Superman” in 1978  Suffered by spinal cord injury  Athletic accident cinemaretro.com Semester A 2024/25 Tissue Engineering nerdsonquads.wordpress.com wikipedia 9/49  Lack of Tissue Replacement Millions of patients are suffering due to damaged or malfunctioning tissue/organ. Spinal Cord Injury Parkinson’s Disease Alzheimer's Disease Heart's Disease Semester A 2024/25 Tissue Engineering 10/49  Limited tissue regeneration Most of our tissue is not spontaneously repaired or stored after damage. Patients are frustrated by the limited supply of tissue available for clinical transplantation. This lack of functional tissue replacements resulted in the deaths of thousands of patients every year. Semester A 2024/25 Tissue Engineering 11/49 What can regenerate spontaneously? Semester A 2024/25 Tissue Engineering 12/49  Waiting list of tissue/organ transplants Approximately one patient is added to the waiting list every 10 minutes; however, on average only 80 organ transplants occur each day. optn.transplant.hrsa.gov Semester A 2024/25 Tissue Engineering sites.psu.edu 13/49  Dolly the sheep Dolly is the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer. Thus, it raise great interests of reproducing lost tissue or organ. Semester A 2024/25 Tissue Engineering http://i.telegraph.co.uk/ 14/49  Unlimited Tissue Engineering? Pet cloning is available now. – www.viagenpets.com – http://en.sooam.com/index.html On December 22, 2001, Cc (carbon copy) was born to a surrogate tabby, in College Station, Texas (A&M) A year later the cloned cat Cc is markedly different than the genetically identical “Rainbow” Left: CC (or Carbon Copy). Right: Rainbow. Photo courtesy TAMU, College of Veterinary Medicine. Semester A 2024/25 Tissue Engineering 15/49  Human cloning.. Theoretically, it is possible to reproduce human of a genetically identical copy However, human cloning has raised controversies because the ethical concern. Several nations to pass laws against human cloning and its legality. Semester A 2024/25 Tissue Engineering 16/49  Vacanti Mouse In 1997, BBC documentary, Tomorrow’s World, showed what is now known as the Vacanti mouse (Cao et al., 1997). The term ‘Tissue engineering’ had become well-known to millions of individuals ngm.nationalgeographic.com Semester A 2024/25 Tissue Engineering wikimedia.org 17/49  Vacanti Mouse Material: PLGA Biology: calf chondrocytes (cartilage cells) Semester A 2024/25 Tissue Engineering 18/49  “Tissue Engineering” “is the application of the principles and methods of engineering and the life science toward the fundamental understanding of structure-function relationships in normal and pathological mammalian tissue and the development of biological substitutes to restore, maintain or improve functions” (Skalak and Fox (Eds.) Tissue Engineering, Alan Liss 1998) “an interdisciplinary field that incorporates and applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue organ or function” (R. Langer and J. Vacanti, Science 1993, 260, 920-926) “The goal of tissue engineering is to restore function through the delivery of living elements which become integrated into the patient” (Vacanti and Langer, Lancet 354, 1999) Semester A 2024/25 Tissue Engineering 19/49  What is “Tissue Engineering”? Cell as a building block that constitutes our body Tissue Engineering is not only for tissue – ORGANS: heart, kidneys, lungs, liver, pancreas and intestines can be transplanted – TISSUES: corneas, middle ear, skin, heart valves, bone, veins, cartilage, tendons, ligaments can be stored in tissue banks and use – CELLS: Stem cells: marrow, peripheral blood stem cells, cord blood stem cells – Blood and Platelets Semester A 2024/25 Tissue Engineering 20/49  Why tissue engineering? Congenital abnormalities require tissue reconstruction Most tissues cannot regenerate following disease or injury Even tissue that regenerate spontaneously may not completely do so if the defect is large Permanent implants are successful, but have their own problems Semester A 2024/25 Tissue Engineering 21/49  Tissue Engineering vs. Regenerative Medicine Tissue Engineering – in vitro – Advantages evaluation of tissue prior to implantation strict environmental control – Disadvantages for incorporation, must be remodeling Regenerative medicine – in vivo – Advantages incorporation under endogenous regulators (including mechanics) physiologic environment – Disadvantages dislodgement and degradation by mechanical stresses in vivo Semester A 2024/25 Tissue Engineering 22/49  Tissue Engineering Paradigm. Things to consider: – Cells – Biocompatible materials – Biochemical factors(e.g., growth factors) – Biophysical factors, (e.g., cyclic mechanical loading) Semester A 2024/25 Tissue Engineering 23/49 Blitterswijk, C. V. (2008). Tissue Engineering  Types of transplants Autografts – harvest tissue from a patient’s own body for transplanting into the same patient Allografts – harvesting tissue from a donor, transplanting into a patient; deceased or living donors Xenografts – removing tissue from an animal for transplantation into a human Man-made materials and devices – artificial hearts, heart valves, etc. Expiration Inspiration Bioartificial Lung Artificial Heart Artificial Lung Semester A 2024/25 Tissue Engineering 24/49  History of Tissue Engineering The first synthetic skin substitute was developed in 1962; however, the first successful tissue-engineered skin products were made in the late 1970s and early 1980s. Why do we need it? Wounds that are more than 1 cm in diameter or that extend deep into the dermis require special treatment to assist in closure. Gold standard: autologous skin grafts – Problems: Injury on the uninjured donor site Source of autologous skin Large area of wound – Can be treated by meshing the skin, at technique in which the skin graft is uniformly perforated and stretched to cover greater areas of the wound – However, slow epithelialization from graft greater graft contraction pronounced crocodile skin. Semester A 2024/25 Tissue Engineering 25/49  Skin Skin grafts are the first engineered tissue construct and were developed by Green and colleague at Harvard Medical School. Keratinocytes isolated from the biopsy could be proliferated by coculturing with a feeder layer of mouse mesenchymal cells, thus expanding ex vivo and expanded the coverage area a thousand-fold in a matter of weeks. First successful product: Epicel Severe burn injury victim after treating skin transplants Semester A 2024/25 Tissue Engineering 26/49  Epicel Epicel: sheets of autologous keratinocytes to cover the injury sites in patients suffering from catastrophic burn injuries Do not have dermis, only a few cells thick and extremely fragile approximately 60–70 patients per year on average Considered as xenogeneic because the use of feeder cells Lack of off-the-shelf availability Cultured keratinocytes on a plastic substrate www.acikbilim.com Semester A 2024/25 Tissue Engineering 27/49  Skin repair Epithelial regeneration – Regenerating the keratinocyte layer by putting on top of the wound cultured autologous keratinocytes or a temporary covering that contains extracellular matrix and growth factors that stimulate keratinocyte proliferation F. Berthiaume, Annu. Rev. Chem. Biomol. Eng. 2011 Semester A 2024/25 Tissue Engineering 28/49  Skin repair Dermal regeneration matrix – The matrices are placed on the wound bed and allowed to integrate and vascularize. After sufficient revascularization of the matrix, these products must be covered with autografts – The matrix degrades while the host’s cells invade and proliferate within it, – Alternative: Alloderm, removing all the cells and keeping only matrix components to prevent immunological response and also reduces the risk of disease transmission F. Berthiaume, Annu. Rev. Chem. Biomol. Eng. 2011Semester A 2024/25 Tissue Engineering 29/49  Skin repair Full-thickness composite skin – The most comprehensive tissue-cultured skin incorporates both living dermis and epidermis, which are usually cultured from allogeneic sources – Product: Dermagraft and Apligraf F. Berthiaume, Annu. Rev. Chem. Biomol. Eng. 2011Semester A 2024/25 Tissue Engineering 30/49  Apligraf First, dermal fibroblasts are seeding in a collagen gel and form a neodermis. Second, a week after, The keratinocytes are grown on top of the neodermis Third, the membrane is exposed to the air-liquid interface to induce differentiation and formation of a keratinized layer. Process takes approximately 3 weeks and uses allogeneic cells, which provides the potential for off-the- shelf availability Although patients will eventually reject it because of the allogeneic cell source, it appears to help restore the dermis and promote keratinocyte migration to close the wound Semester A 2024/25 Tissue Engineering http://bme240.eng.uci.edu/ 31/49  Current limitation Slow revascularization Poor attachment to the wound bed. Dermal components take long time to vascularize Surgeon must balance the pros and cons of using a skin substitute to improve long-term scar appearance and function in the face of increased Lack of – Hair follicles – Sebaceous glands – Sweat glands Semester A 2024/25 Tissue Engineering 32/49  Cartilage A loss of cartilage function is often a result of degenerative joint diseases in the older population and sports injuries in the younger population. Cartilage has limited regenerative ability because it lacks the necessary vasculature to initiate the repair process and exhibits limited chondrocyte proliferation. football.calsci.com Semester A 2024/25 Tissue Engineering www.howardluksmd.com 33/49  Cartilage repair Most cartilage repair technologies work best when used early after injury and in young, healthy individuals as chronic state may create a hostile environment to tissue repair and regeneration Microfracture: the most prevalent marrow-based method where the damaged area is perforated below the subchondral plate, allowing blood to flow and clot in the microfractures Microfracture is a first-line procedure in acute knee injuries for athletes younger than 40 years old. Early treatment after injury has achieved favorable short- term outcomes, but significant deterioration is observed after ∼2 years – imperfect integration of the scar with surrounding healthy cartilage – inferior mechanical properties of the scar itself www.josephbermanmd.com Semester A 2024/25 Tissue Engineering 34/49  Cartilage repair Osteochondral transplantation techniques involve harvesting cartilage together with subchondral bone from nonweight-bearing regions of the joint and placing them in the weight-bearing area of the damage. – Mismatch in the surface shape (convexity) – short supply of autologous donor tissue – Functional for about 5 years – On the other hand, because it is immuno-privileged, approached are proposed toward allografts and cell- free osteochondral graft substitutes. Semester A 2024/25 Tissue Engineering 35/49  Cell-based cartilage repair First developed by Brittberg and colleagues in 1994. Product: Carticel Approach: autologous chondrocytes are harvested from a less weight-bearing area of the joint, extracted from the cartilage explant, and proliferated in culture before implantation. Long-term durability of functional improvement exceeding 10 years! However, injection of chondrocytes may cause significant cell loss and non-uniform cell distribution. Semester A 2024/25 Tissue Engineering biomed.brown.ed 36/49  Scaffold associated implants A technique that uses biodegradable scaffolds to temporarily support the chondrocytes until they are replaced by matrix components synthesized from the implanted cells. Advantages: – reduce lost of chondrocyte – provide a more homogeneous chondrocyte distribution – lessen graft hypertrophy Successful product: – Hyalograft-C Semester A 2024/25 Tissue Engineering ajs.sagepub.com 37/49  Scaffold associated implants As in most cartilage repair therapies, better results were seen in younger patients (in this case