The present invention relates to a particle comprising a functionalized nucleic acid non-covalently associated to a cell-penetrating peptide, wherein:• the functionalized nucleic acid comprises, or consists of:- an HIV integrase-inhibiting oligonucleotide comprising from 11 to 20 contiguous nucleotides and- at least one functionalizing group of the following formula (I) covalently linked to the oligonucleotide:• the cell-penetrating peptide comprises from 12 to 30 contiguous amino acids• the particle is liable to be obtained by contacting the functionalized nucleic acid with the cell-penetrating peptide in a 1/5 to 1/15 molar ratio.
