Your collateral is valid though, just not valid to certain lenders. Why not post a thread? There are probably some people that may be willing to accommodate you if the parameters are right. I'm considering it myself.
If you think it'd valid then give him the loan 
I have seen some good number of people offer such collateral (NFTs) for loans in their own threads, and I haven't seen a single one of them acquire a loan. The fact is that NFTs are illiquid especially after their hype died down.