Current non-melanoma skin cancer treatments work well but have some significant drawbacks. We consider low dose radiotherapy for field treatment to have potential to address the issues of repeated treatment to reduce recurrence, pain, high cost and long clinical wait times during treatment. We have previously developed a topical delivery enhancement technology based on elongated microparticles specifically engineered for field delivery enhancement that makes gold nanoparticle enhanced radiotherapy possible in skin.
In vitro experiment, keratinocyte model HaCat cells were grown 24 well plates. The cells were unexposed or exposed to 20 nm gold nanoparticles alone and in combination with EMP, EMP alone and gold plated EMP. These groups were then treated with 0, 3, 6 and 9 Gy. After 2 hours the cells were fixed and subsequently immunostained for gH2A.X, a marker for dsDNA breaks. Image analysis revealed increased DNA damage in close proximity to the gold plated EMP treated with 6 and 9 Gy and a lower level of DNA damage was observed with gold nanoparticles.
On excised human skin, EMP nanoparticle delivery enhancement was evaluated in liquid formulations using nanoparticles below 500 nm. Dry coating nanoparticles to EMP revealed significant improvements in skin delivery over liquid formulations. The dry-coating technology was optimised using a cross-linked polymer approach that was successfully applied to a number of payloads including 20 nm gold nanoparticles. Two engineered EMP carrying low and high gold nanoparticle payloads were applied to live human skin explants. These treated explants were then exposed to 6 Gy.The explants were embedded and snap frozen within 2 hours of radiotherapy. Sections were evaluated with H&E for epidermal disruption. Only the EMP delivering a high dose of gold nanoparticles showed significant epidermal disruption.
Together these data support the further development of this novel, targeted field therapy for NMSC.