title: Tissue engineering.
abstract: OBJECTIVE
  Regenerative medicine holds promise for the restoration of tissues and organs damaged by wear, trauma, neoplasm, or congenital deformity. Tissue engineering combines the disciplines of cell biology and biomedical engineering to effect the design and maturation of various tissues. Despite progress in some areas of tissue regeneration, there has not been significant translation to clinical practice. This article reviews the present understanding of and advances in regenerative medicine, as well as describing limitations in current techniques and areas that need further development. A discussion of the state of the art in the regeneration of skin, cartilage, bone, adipose tissue, and neural tissue is included.
  
  
  RESULTS
  Differences between extracorporeal and in-vitro tissue engineering are discussed, as well as tissue engineering principles, including the use of bioactive scaffolds, progenitor cells and stem cells, the need for cellular and tissue patterning, microcirculation development, and the use of external stimuli for differentiation. Much needs to be learned about progenitor cell biology, cell-cell interactions, cellular interactions with the extracellular matrix, and about the cues needed for differentiation of functional tissues.
  
  
  CONCLUSIONS
  The current limitations in regenerative medicine techniques and the gaps in current knowledge of cellular biology and tissue development represent significant research opportunities in tissue engineering.
authors: Division of Otolaryngology, Department of Surgery, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536-0293, USA. oaaros2@uky.edu
authors: Oneida
authors: O
authors: Arosarena
mesh_terms: D001698:Biomedical Engineering; D002454:Cell Differentiation; D017690:Cell Transplantation / Q000379:methods; D015509:Developmental Biology / Q000379:methods; D015316:Genetic Therapy / Q000379:methods; D006133:Growth Substances / Q000627:therapeutic use; D006801:Humans; D012038:Regeneration; D013234:Stem Cells / Q000166:cytology; D023822:Tissue Engineering
chemical_list: D006133:Growth Substances