Human papillomaviruses (HPVs) are largely accepted as major etiologic agents for cervical cancer. The implementation of screening and vaccination programs for HPV have reduced cancer incidence and mortality. Although there is still a need to treat patients infected and in the precancerous state, able to clear HPV infection in the early stages of the disease.
Nanotechnology has emerged as a potential therapeutic approach to viral infection and cancer treatment, specifically, DNA-based nanoparticles for antiviral and/or anticancer drugs greatly enhance their bioavailability and increase their target specificity. AS1411 is a G-quadruplex (G4)-forming DNA oligonucleotide that functions as an aptamer of nucleolin (NCL), a protein overexpressed in cancer cells. Two preliminary studies showed the involvement of NCL in the expression of HPV18 oncogene after oligonucleotide binding and HPV16 genome stability.

AS1411 has been used as a drug delivery system and has cellular internalization and anticancer activity by interfering with NCL oncogenic functions. Clinical trials of AS1411 have indicated that it is well tolerated with evidence of therapeutic activity, but improved pharmacology and potency may be required for optimal efficacy. Since G-rich regions have been found in HPVs (LCR, E1, E4 regions) such potential anticancer/ antiviral ligands may be a promising new therapeutic strategy against HPV infection. The development of improved AS1411 derivatives, and association with nanoparticles augments available technological approaches to cancer treatment, as does the development of new screens for quadruplexes and the development of cell-penetrating aptamers. The improvement of the ligands’ selectivity to HPV infected cells obtained through the conjugation with the AS1411-gold nanoparticles demonstrates the ability of these systems to improve the selectivity of potential anticancer/antivirals that, in normal situations, cannot be applied due to their toxicity in healthy tissues. Through their conjugation with the nanoparticles, this roadblock was overtaken, though.

This is an important finding that can be implemented in the pharmaceutical industry because the preliminary ex vivo permeation studies demonstrated the efficacy of the formulation in penetrating and accumulating the nanosystems in the target cells. The micelles were also able to penetrate cervix tissue biopsies of patients with HPV infection in precancerous stages, demonstrating the potential of this system to treat HPV infection in its latent stage, preventing oncogenesis and cervical cancer progression. The administration route of the drug-loadednanosystems was also addressed. The C8-loaded micelles were formulated as a gel for local application in the female genital tract, specifically tissue with precancerous lesions and/or HPV infection.