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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 €0.10 per patch) with a height of 865 ± 6 μm, 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 μL 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.

Objective: The aim of this study was to quantify blood cells and inflammatory markers, involved in the healing process, in exudates from wounds in different healing phases, to assess these markers in order to identify the inflammatory phase of the wounds., Method: Patients who presented with postsurgical wounds, which closed by first and second intention, and those who presented with pressure ulcers (PUs), which were closed by second intention, were included in the study., Results: We examined wounds from 37 patients and collected samples from 52 wounds in the inflammatory phase, 30 in the proliferative phase and 29 in the maturation phase. The number of neutrophils and platelets in the exudate collected from wounds in the inflammatory phase was significantly higher (p<0.001), while the number of lymphocytes, was significantly lower in exudate from wounds in the inflammatory phase (p<0.001). Wound c-reactive protein (CRP) and immunoglobulin G (IgG) levels were higher in the inflammatory group (p<0.001). We found a significantly positive correlation between CRP levels and the percentage of neutrophils and monocytes (r=0.346, p=0.004; r=0.293, p=0.015), and a significantly negative correlation between CRP levels and the percentage of lymphocytes (r=-0.503, p<0.001). A stepwise logistic regression analysis was used to identify an optimal combination of these biomarkers. The optimal biomarker combinations were neutrophils + monocytes + platelets + IgG + CRP, with an area under the curve (AUC) of 0.981 [confidence interval (CI) 95%: 0.955-1.000, p<0.001] for the diagnosis of wounds in the inflammatory phase. The optimal cutpoint yielded 96.9 % sensitivity and 94.6 % specificity. The biomarker combination predicted the inflammatory phase and was superior to individual biomarkers., Conclusion: Our findings suggest that the combination of the markers, percentage of neutrophils and monocytes, platelets, CRP and IgG levels could be useful prognostic indicators of the inflammatory phase.