biotech lecture 1

• Tissue engineering is a biomedical engineering discipline that uses a combination of cells, engineering, materials methods, and suitable biochemical and physicochemical factors to restore, maintain, improve, or replace different types of biological tissues
• Three general components are involved in tissue engineering: (1) reparative cells that can form a functional matrix; (2) an appropriate scaffold for transplantation and support; and (3) bio-reactive molecules, such as cytokines and growth factors that will support and choreograph the formation of the desired tissue.
•  Steps to prepare artificial tissue: 1) BIOPSY (donor-tissue extraction) - either from fluid tissue like blood using centrifugation or apheresis (easier process) or from solid tissue that involves more steps. 
• 2) CELL ISOLATION and CULTIVATION (manipulation with cells) – it is safest to use autologous cells (primary cells extracted from the same person's own healthy tissues to which the artificial tissue will be transplanted), 
•  recently there has been trend to use mesenchymal stem cells from bone marrow that can differentiate into various tissue types. Other types of cells that can be used are allogenic (donor from the same species), heterologous (or xenogenic, donor is different species). In those cases, rejection of the host's immune system and possible disease transmission are risks that need to be considered.
• 3) SCAFFOLDS, seeding, cultivation – implantation or 'seeding' of cells into artificial structure that can support 3-D tissue formation; that resemble the extracellular matrix
• 4) IMPLANTATION - (implantation into living body)
• 5) DETECTION - (property analysis)
• In vivo delivery In vivo gene therapy refers to direct delivery of genetic material either intravenously (through an IV) or locally to a specific organ (eg, directly into the eye)
• Ex vivo delivery

  • Ex vivo gene therapy refers to the process of removing specific cells from a person, genetically altering them in a laboratory, and then transplanting them back into the person.