Sprayed slow-release analgesic (painkiller) nanomedicine for application during abdominal surgery

The objective is to assess the safety and efficacy of a newly-developed analgesic to treat post-operative pain following abdominal surgery. Unlike commonly used analgesics, ours will only need to be applied once, at the time of surgery.Standard drugs to treat pain after abdominal surgery can cause complications, while local analgesics fail to target internal pain. Repeated doses are needed, often with pain between doses. We have developed a single-dose analgesic that is applied to the surgical site and provides continuous pain relief for the duration of recovery. We now need to test our analgesic in animals before we conduct human studies.

Plan of work and impact of our studies 

Mice will undergo abrasion to a 1cm2 area of the abdominal lining to simulate a surgical wound. They will be randomly allocated to receive the spray analgesic (forming our intervention group) or standard postoperative pain control (the control group). Mice will be recovered and observed for pain (Grimace score) and general recovery (Postoperative Severity Score). If our analgesic provides better pain relief it could reduce hospital stays from five to three days, resulting in estimated cost savings of around £1.7billion a year to the NHS.

Animal welfare

Possible adverse effects include failure to provide pain reduction, bacterial infection in the surgical area, and changes in organ function. Animals will be regularly monitored following surgery and immediate action taken to avoid unnecessary harm. 


We have previously assessed our analgesic in the laboratory using cell lines (cultures of animal cells that can be propagated repeatedly). We have seen promising results with a reduction in markers of inflammation without toxic effects. We now need to verify safety and efficacy in a living biological model.


We have discussed with people experienced in animal research to determine the best model and number of animals needed to adequately assess the benefit of our analgesic. A small initial experiment will be performed to optimise the technique and determine the sample size for the definitive study.


Mice are the preferred choice for our experiments because they have many similarities to humans in terms of anatomy and physiological responses. As such, we expect our mice model to provide the required information about how our analgesic might work in humans.


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