A method for non-surgical sterilization of mammals using an antibody-guided nanoparticle carrying cytotoxin to kill gonadal cells exhibiting anti-Mullerian hormone II receptors

Non-surgical, species agnostic animal sterilization

Researchers at Tufts University have devised a novel, fast, and non-surgical means to induce apoptosis in animal gonads. Lipid‐like carriers are used for targeted intracellular delivery of proteins and antibodies that induce cell apoptosis. The procedure is done through single intravenous (IV) injection that does not require anesthesia. Additionally, it is species and sex agnostics.


Features • Species & sex agnostic • No surgery or anesthesia required • Single IV injection – no specialized equipment or training required • Cost-effective


Applications • Animal Sterilization


Patent Status • PCT Publication No. WO 2018-022292 (February 1, 2018) 


The terms ‘spay’ and ‘neuter’ typically conjure images of kittens and puppies undergoing a routine surgical procedure at the behest of a loving owner. While pet owners are typically willing to pay for a surgeon’s time and proper anesthesia, this is not always the case for poultry and livestock, leaving the analogous procedures for these animals crude by comparison. Additionally, stray and shelter animals have no owner to front the costs, forcing shelters, veterinarians, and animal welfare societies to bear them. Non-surgical methods have existed in the past, however they have not been widely adopted due to a lack of systemic safety and a requirement for costly training, among other reasons. There is clearly a need for an inexpensive, non-surgical option for veterinary sterilization.



The technology developed at Tufts relies on lipid-like nanoparticles targeted to the gonads via an anti-anti Mullerian hormone receptor II (AMHRII) antibody to deliver a payload of the intracellular cytotoxic protein Saporin. Importantly, a single IV injection into rats was capable of inducing apoptosis of sertoli and granulosa cells in the testes and ovaries, respectively. These disruptions led to a decreased sperm count and estrous cycle dysfunction, indicative of rat sterility.


Competitive Advantages

This technology is species and sex agnostic as AMHRII is expressed on possibly all animal gonad cells. It is performed through single IV injection. Therefore, no specialized equipment nor training is required. This significantly reduces the costs of the procedure and eliminates post-operative recovery of animals.


Intellectual Property

US Publication No. 2019-0270822 (September 5, 2019)

European Publication No.  3490611 (June 5, 2019)


Tufts University Invention T002164 

Licensing Contact

Emma Anderson