With the integration and development of materials science, microfabrication technology, and modern medicine, microneedles, as a breakthrough technology in minimally invasive interventional diagnosis and treatment, have become an important research direction at the forefront of biomedical engineering due to their ability to penetrate the stratum corneum of the skin, significantly improve drug delivery efficiency, and achieve real-time monitoring of biomarkers.

Recently, the research published in Advanced Materials Technologies by the University of Kochi in Türkiye showed the super hydrophilic hollow microneedle patch prepared by micro nano 3D printing technology, which can effectively collect skin interstitial fluid (ISF) and realize the on-site detection of biomarkers. In this groundbreaking study, Mofang Precision's microArch ® The S230 (accuracy: 2 μ m) 3D printing system has played a key role in providing core technical support for the precision manufacturing of microneedle structures.

As the direct liquid environment for cell life, interstitial fluid accounts for about 75% of extracellular fluid, and its biomarker composition is highly similar to that of blood. Research has shown that ISF contains rich disease-related indicators and is expected to become an ideal sample source to replace traditional blood diagnosis. However, the content of ISF in the dermis layer of the skin is extremely low, and the extraction technology faces significant challenges. Traditional ISF collection methods, such as suction blister and biopsy puncture, not only cause discomfort and skin damage to patients, but may also lead to distorted biomarker concentrations due to tissue damage. Microdialysis technology takes several hours to complete sampling, and membrane permeability limits the range of analytes that can be collected.

Therefore, developing new technologies that can quickly and efficiently extract sufficient amounts of ISF (≥ 1 μ L) has become an urgent task. In this study, the research team successfully prepared multi-channel hollow microneedles with excellent mechanical properties and biocompatibility using Mofang Precision Surface Projection Micro Stereoscopic Lithography (P μ SL) technology. Through Mofang Precision microArch ® S230 3D printing system, researchers designed and manufactured conical microneedle arrays with different heights, substrate diameters, and microchannel numbers. Each microneedle patch contains a 10 × 10 array of microneedles, covering an area of 16 × 16mm ². Scanning electron microscopy (SEM) analysis shows that the diameter of the prepared microneedle tip is about 5 μ m, which is equivalent to the radius of the microneedle tip prepared based on photolithography technology.

Subsequently, this study coated a silicon dioxide layer on the surface of microneedle channels through chemical vapor deposition, significantly improving hydrophilicity and enhancing the ISF adsorption ability through microchannels. After modification, the static water contact angle of the microneedles decreased from about 72 ° to 9 °, indicating a significant improvement in hydrophilicity. This super hydrophilic coating enables microneedles to extract liquid from agarose gel, while untreated microneedles cannot extract any liquid from agarose gel. The silica coated microneedles can be filled with blue dye within a few seconds after inserting the agarose gel, showing the passive liquid absorption ability. Mechanical performance tests have shown that 3D printed microneedles exhibit excellent mechanical properties under compression, shear, and penetration forces. Under a compressive load of up to 0.40 N/needle, the microneedle showed no signs of fracture, confirming its mechanical strength to penetrate the skin without mechanical yielding.

Subsequently, cytotoxicity experiments validated the biocompatibility of 3D printed microneedle patches before and after silica coating. Compared with the control group, cells soaked in culture medium containing microneedles showed comparable cell viability after 24 and 72 hours, indicating that 3D printed microneedles have no toxic effects before and after coating.

Researchers have achieved direct and quantitative analysis of biomarkers in sampled liquids by integrating colorimetric analysis into microneedle patches. And selecting urea and pH as target biomarkers, the integrated microfluidic chamber includes paper-based urea and pH colorimetric analysis methods for detecting urea and pH levels in the extracted ISF. The experimental results show that the patch can effectively detect urea and pH levels in ISF, covering physiological concentrations. The linear correlation coefficient R ² of urea detection is 0.98, and the detection limit is 0.83 mM, indicating the feasibility and effectiveness of this method in practical applications.

The ultra hydrophilic microneedle patch developed in this study can be integrated into various ISF devices, expanding its application for detecting multiple biomarkers in ISF. The passive ISF extraction capability provides significant progress for the design and production of continuous health monitoring devices.

This breakthrough research demonstrates the enormous potential of micro nano 3D printing in the field of biomedical applications. In order to comprehensively improve the printing efficiency of the equipment, S230 has been upgraded to S230A. While continuing the advantage of 2 μ m ultra-high printing accuracy, its integrated automatic level adjustment system realizes the automation of key processes such as platform automatic leveling, dynamic calibration of film stretching, and intelligent adjustment of rolling cutters.

S230A achieves significant production efficiency through intelligent process parameter optimization while ensuring surface quality and dimensional accuracyenhanceTo meet the ultra-high precision 3D printing needs in the field of biomedicine, including the preparation of precision structures such as microneedles, microfluidics, organ chips, and biomimetic devices.

In the future, this super hydrophilic microneedle veneer is expected to be widely used in clinical research, pharmaceutical development, cosmetics, and continuous health monitoring, especially in the management of chronic diseases that require frequent monitoring of biomarkers. By combining Mofang Precision's micro nano 3D printing technology, researchers and engineers can develop more accurate and comfortable health monitoring devices, opening up new possibilities for personalized medicine.