Assessment of epidermal cell viability by near infrared multi-photon microscopy following ballistic delivery of gold micro-particles.

The use of gene guns in ballistically delivering DNA vaccine coated gold micro-particles to skin can potentially damage targeted cells, therefore influencing transfection efficiencies. In this paper, we assess cell death in the viable epidermis by non-invasive near infrared two-photon microscopy following micro-particle bombardment of murine skin. We show that the ballistic delivery of micro-particles to the viable epidermis can result in localised cell death. Furthermore, experimental results show the degree of cell death is dependant on the number of micro-particles delivered per unit of tissue surface area. Micro-particles densities of 0.16+/-0.27 (mean+/-S.D.), 1.35+/-0.285 and 2.72+/-0.47 per 1000 microm(2) resulted in percent deaths of 3.96+/-5.22, 45.91+/-10.89, 90.52+/-12.28, respectively. These results suggest that optimization of transfection by genes administered with gene guns is - among other effects - a compromise of micro-particle payload and cell death.

[1]  W. J. Mulholland,et al.  Characterization of powdered epidermal vaccine delivery with multiphoton microscopy , 2004, Physics in medicine and biology.

[2]  Mark A. F. Kendall,et al.  A ballistic study of micro-particle penetration to the oral mucosa , 2003 .

[3]  William J. Mulholland,et al.  Design and commissioning of a directly coupled in-vivo multiphoton microscope for skin imaging in humans and large animals , 2004, SPIE Optical Systems Design.

[4]  M. Kendall,et al.  NUMERICAL STUDY OF A TRANSIENT GAS AND PARTICLE FLOW IN A HIGH-SPEED NEEDLE-FREE BALLISTIC PARTICULATE VACCINE DELIVERY SYSTEM , 2004 .

[5]  R. Steinman,et al.  Dendritic cells and the control of immunity , 1998, Nature.

[6]  Simon C Watkins,et al.  DNA–based immunization by in vivo transfection of dendritic cells , 1996, Nature Medicine.

[7]  M. Kendall,et al.  Intradermal ballistic delivery of micro-particles into excised human skin for pharmaceutical applications. , 2004, Journal of biomechanics.

[8]  K A Holbrook,et al.  Regional differences in the thickness (cell layers) of the human stratum corneum: an ultrastructural analysis. , 1974, The Journal of investigative dermatology.

[9]  Mark A. F. Kendall,et al.  The delivery of particulate vaccines and drugs to human skin with a practical, hand-held shock tube-based system , 2002 .

[10]  Roger W. Ainsworth,et al.  Measurements of the gas and particle flow within a converging-diverging nozzle for high speed powdered vaccine and drug delivery , 2004 .

[11]  T. Klein,et al.  DELIVERY OF SUBSTANCES INTO CELLS AND TISSUES USING A PARTICLE BOMBARDMENT PROCESS , 1987 .

[12]  G A Briggs,et al.  Biomechanical measurements in microscopically thin stratum corneum using acoustics , 2001, Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging.

[13]  M. Kendall,et al.  Effects of relative humidity and ambient temperature on the ballistic delivery of micro-particles to excised porcine skin. , 2004, The Journal of investigative dermatology.

[14]  P. Amerio,et al.  Role of cytokines in epidermal Langerhans cell migration , 1999, Journal of leukocyte biology.

[15]  W. Wieland,et al.  In vitro investigations on cellular damage induced by high energy shock waves. , 1992, Ultrasound in medicine & biology.

[16]  Mary S. Wu,et al.  Induction of antigen-specific CD8+ T cells, T helper cells, and protective levels of antibody in humans by particle-mediated administration of a hepatitis B virus DNA vaccine. , 2000, Vaccine.

[17]  Y. Koide,et al.  Advantage of gene gun-mediated over intramuscular inoculation of plasmid DNA vaccine in reproducible induction of specific immune responses. , 2000, Vaccine.