Currently there is no way to lend / loan an NFT and ensure that you'll get it back (without collateral). What we've created is an escrow dApp that lets the borrower sign transactions and interact with the blockchain, and the lender can retrieve their NFT as they please.
This project employs Gnosis Safe's custom safe creation and uses specific rules / modules to enable the borrower granular access to the blockchain, while ensuring they can't transfer or sell the NFT. The lender can then retrieve the NFT as they please, or when certain conditions are met--like a period of time has passed.
We mainly altered / used Gnosis Safe's technology for this project. A Gnosis Safe is basically a smart contract with programmable rules in it. Though we didn't have time to create a functional front end, essentially we have a template that, when connected, allows someone to create a Gnosis Safe with their own given borrowing / lending rules. The borrower can then interact with the blockchain through Gnosis Safe's front end, and the lender can withdraw the NFT back to their own wallet after the borrower is done. We used Polygon because deploying contracts requires gas fees and Polygon is a Gnosis Safe--compatible solution here. We used Covalent to pull NFT balance data very easily. We used ENS so the lender can choose who they want to lend it to very easily; they just type in their ENS and hit send.