title: Needle-free delivery of macromolecules through the skin using controllable jet injectors.
abstract: BACKGROUND
  Transdermal delivery of drugs has a number of advantages in comparison to other routes of administration. The mechanical properties of skin, however, impose a barrier to administration and so most compounds are administered using hypodermic needles and syringes. In order to overcome some of the issues associated with the use of needles, a variety of non-needle devices based on jet injection technology has been developed.
  
  
  METHODS
  Jet injection has been used primarily for vaccine administration but has also been used to deliver macromolecules such as hormones, monoclonal antibodies and nucleic acids. A critical component in the more recent success of jet injection technology has been the active control of pressure applied to the drug during the time course of injection.
  
  
  CONCLUSIONS
  Jet injection systems that are electronically controllable and reversible offer significant advantages over conventional injection systems. These devices can consistently create the high pressures and jet speeds necessary to penetrate tissue and then transition smoothly to a lower jet speed for delivery of the remainder of the desired dose. It seems likely that in the future this work will result in smart drug delivery systems incorporated into personal medical devices and medical robots for in-home disease management and healthcare.
authors.affiliation: a 1 Massachusetts Institute of Technology, Department of Mechanical Engineering , 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Nora C
authors.initials: NC
authors.lastname: Hogan
authors.affiliation: b 2 University of Auckland, Auckland Bioengineering Institute and Department of Engineering Science , 70 Symonds Street, Auckland 1010, New Zealand.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Taberner
authors.affiliation: c 3 Massachusetts Institute of Technology, Department of Mechanical Engineering , 77 Massachusetts Avenue, Cambridge, MA 02139, USA +1 617 253 3973 ; +1 617 253 2218 ; Ljones@MIT.edu.
authors.forename: Lynette A
authors.initials: LA
authors.lastname: Jones
authors.affiliation: d 4 Massachusetts Institute of Technology, Department of Mechanical Engineering , 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Ian W
authors.initials: IW
authors.lastname: Hunter
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D016503:Drug Delivery Systems / Q000295:instrumentation*; D006801:Humans; D007277:Injections, Jet / Q000379:methods*; D007279:Injections, Subcutaneous; D046911:Macromolecular Substances / Q000008:administration & dosage*; D009339:Needles; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D012867:Skin / Q000378:metabolism; D014612:Vaccines / Q000008:administration & dosage
chemical_list: D046911:Macromolecular Substances; D004364:Pharmaceutical Preparations; D014612:Vaccines
keywords: drug delivery; needle-free injectors; skin; transdermal; vaccination