Yes, it could be collateral. But Pales response is correct, you'll have to find a lender who wants it as collateral.
Areas that would have to be considered include the value of the Note being offered, the value of the home collateralizing it, the payment history of the borrower, insurance status and more. It would not be an easy loan to do and the original documents would need careful review by counsel to ensure they are valid, meet the lenders requirements and that they are able to be pledged.