Polymer could advance DNA vaccines
AP Pharma, a US specialty pharmaceutical company, has announced that results of a study conducted at the Massachusetts Institute of Technology (MIT) indicate that its proprietary polymer delivery system could advance the clinical utility of DNA vaccines as well as other nucleic acid-based therapeutics against viral infections and cancers.
AP Pharma, a US specialty pharmaceutical company, has announced that results of a study conducted at the Massachusetts Institute of Technology (MIT) indicate that its proprietary polymer delivery system could advance the clinical utility of DNA vaccines as well as other nucleic acid-based therapeutics against viral infections and cancers.
Study results were reported in the paper, 'Molecularly engineered poly (ortho ester) microspheres for enhanced delivery of DNA vaccines,' published online in the February 2004 issue of Nature Materials.1
The study, directed and sponsored by AP Pharma's principal scientist Jorge Heller, in collaboration with an MIT team under the direction of professor Robert Langer and post doctoral fellow Chun Wang, investigated the use of synthetic biodegradable polymers, poly (ortho ester) (POE) microspheres, specifically designed for enhancing the immunogenicity of DNA vaccines. The POE microspheres allowed DNA release in synchrony with the body's immune system, thus increasing the potency of the response. A vaccine based on a model antigen elicited both an antibody response and a cellular immune response in mice when formulated in a specific type of POE microsphere, resulting in suppression of the growth of tumor cells displaying the model antigen.
'There is much interest in developing DNA vaccines to defend against viral infections, such as HIV, as well as various forms of cancer,' said Dr. Heller. 'They have potential as an alternative to conventional vaccines, which are based either on proteins or on killed or weakened pathogens that can potentially infect the recipient. Some other approaches to formulate DNA vaccines have been reported to cause degradation of the DNA. While admittedly early stage, our study results indicate that the molecularly engineered POE microspheres we studied successfully released intact DNA to the appropriate immune system cells without degradation and elicited a potent immune response.' He added: 'This has been a major problem with some other polymer systems that have shown DNA degradation prior to delivery to the cell.'