3D printed microneedles for anticancer therapy of skin tumours.

In this study, novel 3D printed polymeric microneedle arrays were fabricated for enhanced cisplatin delivery to A-431 epidermoid skin tumours for cancer treatment. The microneedles were built by selectively photopolymerising consecutive layers of a biocompatible photopolymer resin using stereolithography (SLA), followed by coating of cisplatin formulations using inkjet dispensing on the needle surface. The printability via SLA was optimized to improve microneedle mechanical properties and optical coherence tomography analysis showed excellent piercing capacity of 3D printed microneedles to an 80% penetration depth. Franz cell diffusion studies revealed rapid cisplatin release rates of 80-90% within 1 h and in vivo evaluation with Balb/c nude mice presented sufficient cisplatin permeabilization with high anticancer activity and tumour regression. Histopathology analysis confirmed the tumour inhibition effect, showing demarcated lesions with thin fibrous capsules and necrotic cores. The use of 3D printed microneedles demonstrates the potential for in-vivo transdermal delivery of anticancer drugs.