Liposome applications in the veterinary field

Abstract

In the field of veterinary medicine, liposomes are the most widespread nanotechnological tool. Already for some time, they have been applied in animal therapies to improve delivery of different drugs, comprising analgesic, antiviral, antimicrobial, antifungal, and anticancer agents. More recently, with the rise of recombinant DNA technologies, liposomes have been included in veterinary vaccine formulations to entrap antigen-coding DNAs, siRNAs, peptides, and recombinant antigens, as well as effectors of the innate immune system, in order to elicit protective responses against viruses, bacteria and parasites. Reported applications include their use in companion and productive animals, among others horse, dog, cattle, poultry, and fish. Liposomes are generally well tolerated and, in accordance with their purpose, may be delivered through the intramuscular, subcutaneous, intravenous, ocular, and/or intranasal route to their desired target. In order to achieve a more specific tissue targeting, engineering of liposomes has also been described in the veterinary field. Besides therapeutics, liposomes have also been applied in transfection technologies and in the cryopreservation of stallion or bull semen. Use of liposomes can be limited by the high manufacturing costs of lipid synthesis or purification. Therefore, the formulation of low-cost liposomes made of non-purified lipid mixtures will open the possibility of large-scale applications in animal productive systems. This chapter presents an overview on possibilities, advantages, and perspectives of liposome employment for veterinary use.