Granular permissions with module data

Hello,

I am looking for suggestions on how I could approach this problem. I am developing a site with many different departments that all have similar structured data. I want to create a custom module, say "highlight" which would have an image, a title text, body text, and department dropdown. The department dropdown would specify which department owns/uses that highlight.

Each department on my site will use this module's data data on their pages and each department administers their own content.

I am wondering if there is any way I can have just the one module where I can control the permissions such that each department can only administer their own content? Otherwise, I would need to create a dedicated module per department. I have dozens of departments, so that's not workable.

I was thinking I might be able to customize the backend pages perhaps? Maybe I can trap some type of PreLoad, PreSave, etc. events in the backend pages where I can do my own permissions checking? Is that feasible?

Perhaps I am overlooking a simpler way of accomplishing this?

Thanks,
Jeff