Scientists design flexible patch for precision drug delivery to complex organs

BEIJING -- Imagine a microscopic "drug courier" that doesn't flood the whole body but instead knocks gently on the doors of only sick cells, and then slips medicine directly inside them. This vision is now one step closer to reality, thanks to a breakthrough bioelectronic patch that hugs organs like a second skin.

An international team, led by scientists from Beihang University in Beijing, has developed an ultra-flexible bioelectronic patch capable of conforming to irregularly shaped organs, such as ovaries and kidneys, for precise and localized drug or gene delivery.

Dubbed POCKET, the device mimics a "smart electronic garment" that wraps tightly around organs, overcoming a major limitation of traditional systemic drug administration, which tended to be characterized by off-target effects and poor cellular uptake, according to a study published on Tuesday in the journal Cell.

Their work was inspired by a heartbreaking clinical dilemma, namely the need for women carrying hereditary BRCA1 mutations to have both ovaries and fallopian tubes removed to prevent cancer, thus permanently sacrificing their fertility. "Isn't there any other way?" Patients often ask tearfully when faced with this difficult choice.

Notably, existing gene therapies, like viral vectors, carry risks of integrating into germ line genomes and contaminating the human gene pool, rendering them prohibited for use in dealing with sensitive reproductive organs.

The research team pivoted to a physical approach, with electric fields employed to open cell membranes, thereby enabling precise depth control to target only somatic cells on the ovarian surface, while avoiding contamination of germ lines.

However, the ovary's rugged, highly irregular surface prevents conventional devices from achieving conformal contact.

In trying to solve this challenge, the researchers drew inspiration from the art of paper cutting. They engineered a customizable patch that achieves over 95 percent surface coverage on complex anatomies. The four-layered device integrates nanopores, a drug-loaded hydrogel reservoir, silver nanowire electrodes and a flexible substrate, all patterned via femtosecond laser processing.

When a low-voltage current is applied, the nanopores generate localized electric fields that temporarily open microscopic channels in adjacent cell membranes, allowing therapeutics to enter cells directly, the study notes.

This method boosts delivery efficiency by nearly 1,000-fold compared to passive diffusion, while avoiding damage to deeper tissues.

In preclinical trials, the patch successfully delivered BRCA1 gene therapy to the surface cells of ovaries in mice without affecting reproductive cells, reducing cancer risk and restoring fertility.

In kidney transplant models, localized delivery of anti-inflammatory medicine using POCKET protected renal function and eliminated systemic side effects like osteoporosis and immunosuppression, which are seen when oral steroids are used.

This technology offers a new paradigm for treating diseases in sensitive or structurally complex organs, said Chang Lingqian from Beihang University, the paper's co-corresponding author.

The platform could be adapted for treating diabetes, retinal disorders, rheumatoid arthritis and beyond, Chang added.