The Florida company Viragen, which has gained rights to advanced electroporation technology developed by RMR Technologies and the University of South Florida in Tampa, has been granted the licence to commercialise avian transgenic technology fromh Scotland's Roslin Institute, known for its cloned sheep Dolly.
Electroporation technology is based on a highly developed electrode device and uses a specific combination of pulsed electric fields to introduce a gene sequence into the chick embryo. The goal is to introduce a gene encoding a therapeutic protein into the chicken and thus enable the breeding of generations of chickens that also express this gene.
Initial feasibility studies were conducted at the University of South Florida and the work is being transferred to Roslin for further evaluation, said Viragen's research director Professor William H. Stimson, discussing the project at Biotech 2004 at Florida International University last week.
The project aims to breed flocks of transgenic chickens capable of producing high volumes of protein-based drugs, such as cancer-fighting monoclonal antibodies, which would be expressed in the whites of their eggs.
According to the companies, the alternative to standard biomanufacturing techniques would have advantages in ease of scale- up, lower costs of production and quality of the product produced. The proportion of protein drugs, including monoclonal antibodies, under development is forecast to be expanding rapidly but there are a number of manufacturing constraints, including lack of adequate facilities.
"Electroporation is one of three different gene delivery systems we are examining so that we may hold a portfolio of techniques that could be capable of delivering a range of gene constructs designed to express therapeutic proteins in the egg white of hens," said Stimson.
'Electroporation' describes the use of pulsed electric fields to temporarily open microscopic pores in membranes which allow molecules to pass from one side of the cell membrane to the other. When the pulses are properly sequenced, microscopic pores reseal spontaneously and the treated cells continue to grow and function modified by the materials that have been introduced into the cells.
Dr Richard Heller, chief scientific officer at RMR, said it differs significantly from 'standard' electroporation techniques "in the configuration of the electrode and the resulting electrical pulse patterns".