The potential use of microneedles as an alternative method for skin cancer treatment

Background: Non-melanoma skin cancers (NMSC) are one of the most common cancers in humans, representing 80% of skin cancer cases each year. The majority of NMSCs (80%-90%) occur on the head and neck and surgical excision is typically the treatment of choice. However, this is often accompanied by serious side effects including changes to appearance with immense consequences on the patients’ quality of life. One way to achieve eradication of the cancer with good cosmetic outcome may be by localized, targeted immunotherapy. Delivery, at the tumour site, of therapeutic amounts of cytokines that can trigger natural killer cells may be achieved using microneedle technologies.
Objective: To investigate whether microneedles can provide a core scientific platform from which novel, non-invasive delivery systems can be developed for the direct and localised delivery of therapeutic amounts of cytokines for immunotherapy. Tumour necrosis factor A (TNF-a) is used to investigate the proof-of-principle concept.
Methods: Rapidly dissolving microneedle devices made of carbohydrate formulations were prepared by a low vacuum deposition method, each containing 1μm of TNF-a. Skin diffusion was studied using Franz cells and porcine skin and ELISA to quantify TNF-a in the receptor phase.
Results: Initial data showed that it is possible to integrate within the microneedle formulation (consisting of carboxymethyl cellulose, maltose and trehalose) small doses of TNF-a. Diffusion studies showed enhanced distribution of TNF-a in the skin when used through the microneedle formulation compared to the control (disk without needles consisting of same sugar-TNF-α composition as microneedle array).
Conclusion: Preliminary results show that dissolving microneedles can potentially provide an enhanced non-invasive method for treating skin cancer via the localized delivery of immunotherapeutics. These can be ultimately developed into patches that patients can self-administer thus improving patient compliance and economic burden.