Tissue engineering

• Current medical practices for replacing defective tissues?

  • Synthetic implants: Poor biocompatibility and Mechanical Failure
  • Transplants: Rejection, Disease transmission, Availability of donor organs, Cost
  • Ultimate Aim Of Tissue Engineering is to solve the problem of availability of donor organs and tissue rejection
• Issues with current tissue regeneration technique:

  • Difficulties in creating vascularised tissue constructs
  • Insufficient mechanical strength of engineered tissues
  • Replicating cellular organisation in complex tissues
• Scaffold required properties:

  • Self Supporting
  • Porous
  • Biodegradable
  • Non Toxic
• Main Components of Tissue Engineering

  1. Cells: taken from patient to culture and seed onto scaffold
  2. Scaffold: Allows cells to survive, communicate and differentiate in 3D whilst directing cell development, nutrient flow and removal of waste metabolites
  3. Cell Signals: macromolecules produced by the cells that Instructs the cells to behave as they should
• Extra cellular matrix (ECM)

  • The glue that holds all the cells together in the body
  • Made of proteins, mainly collagen
  • Gives structure, allows cells to attach and move products in an out of tissue.
  • Cells they can sense and feel what they’re attached to, and this will direct the cell phenotype.
• Holoclar

  • Autologous Stem Cell Implant
  • Limbal stem cell deficiency of the corneal epithelium–Burns or trauma
  • Stem cells biopsy taken from eye, and gown into a fibrin scaffold which is implanted back into the patient
  • Patient receiving treatment is also the donor
• Apligraf:

  • Living bi-layered skin substitute

  1. epidermal layer is formed by human keratinocytes
  2. dermal layer is composed of human fibroblasts in a bovine Type I collagen lattice

  • Manufactured under aseptic conditions from human neonatal male foreskin tissue
  • Indicated for non-infected skin ulcers due to venous insufficiency which have not responded to conventional ulcer therapy.
• Tissue-engineered product: "cells or tissues that have been subject to substantial manipulation with a view to regenerating, repairing or replacing a human tissue"