title: Drug delivery in soft tissue engineering.
abstract: BACKGROUND
  Tissue defects, sustained through disease or trauma, present enormous challenges in regenerative medicine. Modern tissue engineering (TE) aims at replacing or repairing these defects through a combined approach of biodegradable scaffolds, suitable cell sources and appropriate environmental cues, such as biomolecules presented on scaffold surfaces or sustainably released from within.
  
  
  METHODS
  This review provides a brief overview of the various drugs and bioactive molecules of interest to TE, as well as a selection of materials that have been proposed for TE scaffolds and matrices in the past. It then proceeds to discuss encapsulation, immobilization and controlled release strategies for bioactive proteins, before discussing recent advances in this area with a special focus on soft TE.
  
  
  CONCLUSIONS
  Overall, minimal clinical success has been achieved so far in using growth factor, morphogen, or adhesion factor modified scaffolds and matrices; only one growth factor delivery system (Regranex Gel), has been approved by the FDA for clinical use, with only a handful of other growth factors being approved for human use so far. However, many more growth factors are currently in clinical Phase I - II or preclinical trials and many delivery systems utilize materials already approved by the FDA for other purposes. With respect to drug delivery in soft TE, a combination of increased research efforts in hydrogel and support material development as well as growth factor development is needed before clinical success is realized.
authors.affiliation: The University of Melbourne, Department of Chemical and Biomolecular Engineering , Parkville VIC, Australia. kladewig@unimelb.edu.au
authors.forename: Katharina
authors.initials: K
authors.lastname: Ladewig
mesh_terms: D000818:Animals; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D016503:Drug Delivery Systems / Q000639:trends; D006133:Growth Substances / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D020100:Hydrogels; D055767:Immobilized Proteins; D044968:Regenerative Medicine / Q000379:methods; D017695:Soft Tissue Injuries / Q000628:therapy; D023822:Tissue Engineering / Q000639:trends; D054457:Tissue Scaffolds
chemical_list: D003692:Delayed-Action Preparations; D006133:Growth Substances; D020100:Hydrogels; D055767:Immobilized Proteins