Use of a composition comprising nanoparticles, said composition having the general formula AO x -(L-Me n+ ) I , for obtaining a cicatrizing topical-treatment product for cicatrizing the skin of a user and/or a burn topical-treatment product for treating burns on the skin of a user, AO x being a metal or metalloid oxide in which x indicates the number of the Oxygen atom(s) (O) bonded to the metal (A) atom, Me n+ being a metal ion, wherein L is a molecule comprising at least a first functional group bonded to said metal or metalloid oxide AO x , and at least a second functional group bonded to said metal ion Me + , said first functional group comprising boronic (-B(OH) 2 ), and/or phosphonic (-PO 3 H 2 ) functionality, i being the number of (L-Me n+ ) groups bound to the metal oxide AO x .