Dermal Toxicity of Nanoparticles: A Review of Recent Progress

Nanoparticles (NPs) have gained attention as dermal drug delivery vehicles for several skin diseases, including the theranostic application of skin cancer. In recent times, the use of NP-based therapeutics has expanded to prevent and treat skin infections, protect against UV rays, and aid in scar reduction by accelerating skin cell repair. Despite their therapeutic benefits, the short- and long-term dermal toxicity of NPs poses concerns for clinical applications of NP-based dermal drug delivery. Intentional or unintentional contact of inorganic or organic NPs can lead to skin irritation, photosensitivity, or inflammation via the production of inflammatory cytokines (e.g., IL-5, IL-13, IL-17, and TNF-α) and proinflammatory cytokines (e.g., IL-6, IL-1β, and TNF-α). Additionally, both inorganic and organic NPs can cause collagen depletion. More importantly, genotoxic events can occur with their topical application. In this review, we will report on the dermal application of different NPs and highlight their biodegradability and safety concerns to guide the development of next-generation treatment modalities.