Low-Frequency Sonophoresis: Application to the Transdermal Delivery of Macromolecules and Hydrophilic Drugs

Importance of the field: Transdermal delivery of macromolecules provides an attractive alternative route of drug administration when compared to oral delivery and hypodermic injection because of its ability to bypass the harsh gastrointestinal tract and deliver therapeutics non-invasively. However, the barrier properties of the skin only allow small, hydrophobic permeants to traverse the skin passively, greatly limiting the number of molecules that can be delivered via this route. The use of low-frequency ultrasound for the transdermal delivery of drugs, referred to as low-frequency sonophoresis (LFS), has been shown to increase skin permeability to a wide range of therapeutic compounds, including both hydrophilic molecules and macromolecules. Recent research has demonstrated the feasibility of delivering proteins, hormones, vaccines, liposomes and other nanoparticles through LFS-treated skin. In vivo studies have also established that LFS can act as a physical immunization adjuvant. LFS technology is already clinically available for use with topical anesthetics, with other technologies currently under investigation. Areas covered in this review: This review provides an overview of mechanisms associated with LFS-mediated transdermal delivery, followed by an in-depth discussion of the current applications of LFS technology for the delivery of hydrophilic drugs and macromolecules, including its use in clinical applications. What the reader will gain: The reader will gain an insight into the field of LFS-mediated transdermal drug delivery, including how the use of this technology can improve on more traditional drug delivery methods. Take home message: Ultrasound technology has the potential to impact many more transdermal delivery platforms in the future due to its unique ability to enhance skin permeability in a controlled manner.National Institutes of Health (U.S.) (Grant EB-00351)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Grant DAAD-19-02-D-002

Characterization of antigen-presenting properties of tumour cells using virus-specific cytotoxic T lymphocytes

Immunotherapy of tumours by induction of tumour-specific cytotoxic T-lymphocytes (CTLs) will only be effective for tumours with a functional antigen processing and presentation machinery. However, many tumours are known to down-regulate expression of major histocompatibility complex (MHC) class I molecules and/or to impair antigen processing. It is therefore desirable to evaluate the ability of a given tumour to present antigenic epitopes before developing an immunotherapy protocol. In this study we have used influenza virus as a tool to determine the antigen-presenting capacities of the murine neuroblastoma C1300 cell line NB41A3, a frequently used model for human neuroblastoma. Immunofluorescence analyses revealed low and moderate expression of MHC class I molecules Ddand Kkrespectively. Nevertheless, infected NB41A3 cells were lysed efficiently by influenza-specific CTLs. These results demonstrate that all steps of the antigen-processing pathway function properly in the NB tumour cells, and that the limited MHC class I expression suffices for efficient recognition by CTLs. In addition, lysis of the NB tumour cells shows that the cells are susceptible to CTL-induced apoptosis, a pathway that is often impaired in tumour cells. These characteristics make neuroblastoma a suitable target for immunotherapy. The presented assay allows evaluation of various immunological properties of tumour cells and, thus, represents a valuable tool to assess whether a given tumour will be susceptible to immunotherapy or not. Copyright 2000 Cancer Research Campaign. © 2000 Cancer Research Campaig

A Uniform Genomic Minor Histocompatibility Antigen Typing Methodology and Database Designed to Facilitate Clinical Applications

BACKGROUND: Minor Histocompatibility (H) antigen mismatches significantly influence the outcome of HLA-matched allogeneic stem cell transplantation. The molecular identification of human H antigens is increasing rapidly. In parallel, clinical application of minor H antigen typing has gained interest. So far, relevant and simple tools to analyze the minor H antigens in a quick and reliable way are lacking. METHODOLOGY AND FINDINGS: We developed a uniform PCR with sequence-specific primers (PCR-SSP) for 10 different autosomal minor H antigens and H-Y. This genomic minor H antigen typing methodology allows easy incorporation in the routine HLA typing procedures. DNA from previously typed EBV-LCL was used to validate the methodology. To facilitate easy interpretation for clinical purposes, a minor H database named dbMinor (http://www.lumc.nl/dbminor) was developed. Input of the minor H antigen typing results subsequently provides all relevant information for a given patient/donor pair and additional information on the putative graft-versus-host, graft-versus-tumor and host-versus-graft reactivities. SIGNIFICANCE: A simple, uniform and rapid methodology was developed enabling determination of minor H antigen genotypes of all currently identified minor H antigens. A dbMinor database was developed to interpret the genomic typing for its potential clinical relevance. The combination of the minor H antigen genomic typing methodology with the online dbMinor database and applications facilitates the clinical application of minor H antigens anti-tumor targets after stem cell transplantation