Integrated 3D-Printed Hollow Microneedle Array and Lateral Flow Immunoassay for Point-of-Care Wound Healing Monitoring

Chronic wound management requires continuous monitoring to assess healing and guide treatment. We developed a hollow microneedle array patch integrated with a lateral flow immunoassay strip to address the need for convenient, home-based diagnostics. This device extracts wound exudate directly from the wound matrix, overcoming the limitations of conventional swab sampling, which relies on surface exudate collection. The patch provides a minimally invasive, rapid solution to assess the wound healing phase. The immunoassay delivers a colorimetric signal visible to the naked eye, facilitating straightforward interpretation by clinicians within 10 min. In a clinical study involving 90 patients, matrix metalloproteinase 8 (MMP-8) was identified as a critical biomarker, achieving 80.3% sensitivity in detecting the proliferative phase. A specific lateral flow immunoassay for MMP-8 was developed with a detection limit of 0.7 ng/mL, lower than the threshold level for the proliferative healing phase (164.7 ng/mL). The hollow microneedle array patch was 3D-printed for cost-efficiency (less than <euro>0.10 per patch) with a height of 865 +/- 6 mu m, allowing for a painless, easy sampling. Mechanical tests confirmed the durability of the patch, while cytotoxicity assays demonstrated its biocompatibility. Prevalidation using an ex vivo skin model showed the patch could extract 61 +/- 6 mu L of exudate, with a 122% recovery rate for MMP-8 detection, highlighting its efficiency in biomarker extraction. This approach represents a significant advance in decentralized wound care, offering a low-cost, user-friendly tool for at-home monitoring of chronic wounds, potentially improving early intervention and reducing hospital visits.