Tellurium nanoparticles and Fucoidan-loaded dissolvable microneedles for combined photothermal therapy and anti-angiogenesis in melanoma treatment.

Melanoma, an aggressive skin tumor, is prone to metastasis, significantly reducing patient survival rates once it occurs. Tumor microvascularity is a key factor in metastasis, making the inhibition of microvascular formation crucial. Emerging photothermal therapy (PTT) and microneedles (MNs) have garnered attention due to their non-invasive and controllable nature. In this study, we designed dissolvable MNs loaded with bovine serum albumin (BSA)-coated tellurium nanoparticles (Te NPs) and fucoidan for comprehensive melanoma treatment. Poly (2-ethyl-2-oxazoline) (PetOx) and chondroitin sulfate (CS) were employed to fabricate dissolvable MNs. Polycaprolactone (PCL), a non-water-soluble material, was used as the substrate. Te NPs, with their strong photothermal conversion capability, acted as the photothermal agent. Fucoidan, derived from brown algae, possesses anti-tumor and angiogenesis inhibition activities. Upon insertion into the skin, the microneedle tip dissolves in the tissue fluid, releasing Te NPs and fucoidan, while the substrate is removed. Under near-infrared (NIR) laser irradiation, Te NPs achieve PTT, effectively killing tumor cells. Fucoidan inhibits tumor growth by obstructing angiogenesis, thereby cutting off the tumor's nutrient supply. The designed MNs achieved effective tumor suppression through combination therapy with minimal in vivo side effects, providing a safe and effective melanoma treatment.