# Self-propelled gas nanomotor-integrated microneedles for melanoma therapy: Dual-action in situ eradication and metastatic suppression

## TL;DR

A new microneedle patch with gas-powered motors improves drug delivery to melanoma tumors and helps prevent cancer spread.

## Contribution

A gas propulsion mechanism in microneedles enables deeper drug delivery and combines therapies to suppress melanoma and its metastasis.

## Key findings

- Gas motor-driven microneedles significantly enhance subcutaneous drug penetration and diffusion.
- The patch combines photothermal therapy and chemotherapy to kill melanoma cells and induce immunogenic cell death.
- Anti-PD-1 antibodies in the patch activate systemic immune responses and suppress remote tumors.

## Abstract

Skin cancer, particularly malignant melanoma, is one of the most prevalent cancers globally, affecting millions annually. Traditional treatments like excision, chemotherapy, and immunotherapy often fail due to their invasiveness, toxicity, and poor drug delivery efficiency caused by skin barriers. Microneedles (MNs) offer a minimally invasive alternative, directly penetrating the skin to deliver drugs to tumor sites while minimizing side effects. However, their penetration depth is limited, and they do not address metastatic lesions. This study developed a gas motor-driven multi-responsive microneedle patch that significantly enhances subcutaneous drug penetration through a gas propulsion mechanism, greatly expanding the drug's diffusion range. Combined with photothermal therapy (PTT) and chemotherapy, this approach rapidly kills melanoma cells locally, induces immunogenic cell death (ICD), and uses anti-PD-1 antibodies (aPD-1) targeting immune checkpoints to enhance efficacy, overcome tumor immune escape, and activate systemic immune responses, achieving remote tumor suppression through local treatment only.

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