As a condition to the grant or continuation of aid to an indigent, the board of supervisors may require, as security for the moneys so expended, that the applicant transfer or grant to it such property or interest in property as the applicant has, or such portion thereof or estate therein or lien thereon as the board specifies. Such property shall be managed by the board of supervisors and the net income thereof shall be applied to the reimbursement of the county for the aid granted, and any surplus in excess of such reimbursement shall be paid to the indigent. In the case of any estate, interest, or lien in such property held by the board, or any right of management transferred thereto, the board shall have all the powers of an attorney in fact for the indigent as to such estate, interest, or lien, and may sell, lease, or transfer the same, defend and prosecute all suits concerning it, pay all just claims against it and be reimbursed out of the proceeds, and do all things necessary for the protection, preservation, and management thereof. Any such estate, interest, or lien shall be held by the board, subject to the claim of the county for reimbursement for aid granted to the applicant or for moneys expended in its management, preservation, or protection, and such reimbursement shall constitute a preferred claim against such estate, interest, or lien.