Artelon is another interesting company doing similar...

Artelon is another interesting company doing similar regenerative things with biodegradable polymers- but they are less focused on dermis regeneration and more focused on ligament/ tendon regeneration.
https://www.artelon.com/

A more direct competitor to Polynovo does seem to be the cryogel wound dressing OxoBand if others have not heard of it- it is an oxygen releasing dressing- has been trialled successfully for diabetic ulcers as well as several other wound types

I think others have already mentioned Vanderbilt- they are working with US army researchers on a range of applications for their PTKUR product
Going through a few papers- the increasing research, use and testing of degradable foam like medical devices are being tested for:
Repair of bladder instead of using intestinal tissue (the gold std)
Dermal wounds including diabetic wounds and other problematic such as pressure wounds
Abdominal wall repair: hernias- current used surgical meshes arent biodegradable- trialling Poly ether eter urethane (PEEU)
Cartlidge regeneration with products like Actifit
Bone grafting
Cardiac valves regeneration and even blood vessels!
The potential applications of various biodegradables seems almost endless