A composition comprising (i) a virus-like particle, wherein said virus-like particle is a virus-like particle of an RNA bacteriophage Qβ, and (ii) an oligonucleotide, wherein said oligonucleotide has the nucleic acid sequence "G10" GGGGGGGGGG GACGATCGTC GGGGGGGGGG (SEQ ID NO:8), and wherein said oligonucleotide is packaged into said virus-like particle; wherein said composition is obtainable by a process for producing said composition, said process comprising the steps of: (a) providing coat protein of said RNA bacteriophage Qβ, wherein said coat protein consists of an amino acid sequence selected from the group consisting of: (a) SEQ ID NO:10; and (b) a mixture of SEQ ID NO:10 and SEQ ID NO: 11; (b) providing an oligonucleotide, (i) wherein said oligonucleotide comprises at least one poly G stretch; and (ii) wherein said oligonucleotide comprise a relative peak start time of 50 to 110 %, wherein said relative peak start time is determined in size exclusion HPLC with the capsid of said RNA bacteriophage Qβ as the standard; (c) generating a mixture, wherein said mixture comprises: (i) said coat protein, wherein preferably the concentration of said coat protein in said mixture is 1 to 4 mg/ml, more preferably 2.5 mg/ml, and/or wherein further preferably the concentration of said oligonucleotide in said mixture is 25 to 100 μM, more preferably 62.5 μM; (ii) an agent capable of preventing the self-assembly of said coat protein, wherein preferably said agent comprises a denaturing compound selected from urea and guanidiniumhydrochloride, wherein further preferably said denaturing compound is urea, and wherein still further preferably the concentration of said urea in said mixture is 0.25 to 7.2 M, preferably 1 M; (iii) said oligonucleotide; (d) removing said agent from said mixture, wherein preferably said removing of said agent from said mixture is performed by a first buffer exchange with a first buffer, wherein said first buffer comprises sodium chloride, wherein preferably the concentration of said sodium chloride in said first buffer is 0 to 1 M, preferably 0 to 550 mM, more preferably 0 to 350 mM, still more preferably 50 to 350 mM, and most preferably 250 mM; and (e) allowing said coat protein to self assemble into a virus-like particle. (i) a virus-like particle, wherein said virus-like particle is a virus-like particle of an RNA bacteriophage Qβ, and (ii) an oligonucleotide, wherein said oligonucleotide has the nucleic acid sequence "G10" GGGGGGGGGG GACGATCGTC GGGGGGGGGG (SEQ ID NO:8), and wherein said oligonucleotide is packaged into said virus-like particle; (a) providing coat protein of said RNA bacteriophage Qβ, wherein said coat protein consists of an amino acid sequence selected from the group consisting of: (a) SEQ ID NO:10; and (b) a mixture of SEQ ID NO:10 and SEQ ID NO: 11; (b) providing an oligonucleotide, (i) wherein said oligonucleotide comprises at least one poly G stretch; and (ii) wherein said oligonucleotide comprise a relative peak start time of 50 to 110 %, wherein said relative peak start time is determined in size exclusion HPLC with the capsid of said RNA bacteriophage Qβ as the standard; (i) wherein said oligonucleotide comprises at least one poly G stretch; and (ii) wherein said oligonucleotide comprise a relative peak start time of 50 to 110 %, wherein said relative peak start time is determined in size exclusion HPLC with the capsid of said RNA bacteriophage Qβ as the standard; (c) generating a mixture, wherein said mixture comprises: (i) said coat protein, wherein preferably the concentration of said coat protein in said mixture is 1 to 4 mg/ml, more preferably 2.5 mg/ml, and/or wherein further preferably the concentration of said oligonucleotide in said mixture is 25 to 100 μM, more preferably 62.5 μM; (ii) an agent capable of preventing the self-assembly of said coat protein, wherein preferably said agent comprises a denaturing compound selected from urea and guanidiniumhydrochloride, wherein further preferably said denaturing compound is urea, and wherein still further preferably the concentration of said urea in said mixture is 0.25 to 7.2 M, preferably 1 M; (iii) said oligonucleotide; (i) said coat protein, wherein preferably the concentration of said coat protein in said mixture is 1 to 4 mg/ml, more preferably 2.5 mg/ml, and/or wherein further preferably the concentration of said oligonucleotide in said mixture is 25 to 100 μM, more preferably 62.5 μM; (ii) an agent capable of preventing the self-assembly of said coat protein, wherein preferably said agent comprises a denaturing compound selected from urea and guanidiniumhydrochloride, wherein further preferably said denaturing compound is urea, and wherein still further preferably the concentration of said urea in said mixture is 0.25 to 7.2 M, preferably 1 M; (iii) said oligonucleotide; (d) removing said agent from said mixture, wherein preferably said removing of said agent from said mixture is performed by a first buffer exchange with a first buffer, wherein said first buffer comprises sodium chloride, wherein preferably the concentration of said sodium chloride in said first buffer is 0 to 1 M, preferably 0 to 550 mM, more preferably 0 to 350 mM, still more preferably 50 to 350 mM, and most preferably 250 mM; and (e) allowing said coat protein to self assemble into a virus-like particle.