Microneedle therapy not only shines brightly in clinical applications, but also plays an increasingly important role in drug development and basic scientific research. It provides scientists with an unprecedented tool for studying skin barrier function, the mechanism of drug transdermal penetration, and minimally invasive acquisition of biological samples.

During the drug development stage, the core function of microneedles is manifested in the in vitro evaluation model for transdermal drug delivery. The traditional Franz diffusion chamber requires the use of isolated skin, applying the drug to the surface of the skin, and then measuring the drug concentration in the receiving chamber. This method is time-consuming, has poor repeatability, and cannot simulate the true mechanical state of the skin. The microneedle array can serve as a standardized "skin perforation tool," creating uniform and consistent microchannels on isolated skin, thereby establishing a high-throughput transdermal screening platform. Pharmaceutical companies can utilize this platform to rapidly test the transdermal rates of different formulations and compounds of different molecular weights under the assistance of microneedles, thereby screening out the optimal drug delivery scheme.

In basic research, the role of microneedles lies in the precise manipulation of the skin microenvironment. Researchers can use microneedles of different lengths and densities to study the distribution of immune cells, the density of nerve endings, and the vascular network at different layers of the skin. For instance, by injecting fluorescently labeled tracers into specific depths using microneedles and then observing their diffusion paths in the skin using a two-photon microscope, the dynamics of lymphatic drainage and drug clearance in the skin can be revealed. These data are crucial for understanding the pathogenesis of skin diseases and optimizing drug delivery strategies.

The role of microneedles in biological sample collection has greatly facilitated scientific research. Traditional skin biopsies require surgical removal of tissue blocks, which cause significant trauma and scarring. Microneedle arrays can collect hundreds of tiny tissue cores at once, each with a diameter of only a few hundred micrometers and with controllable depth. These micro-tissue samples can be subjected to histological staining, gene expression analysis, and proteomics research, and the small wounds at the donor site can heal within a few days. This "minimally invasive biopsy" technology makes it possible to longitudinally track the evolution of skin lesions, for example, in studies of psoriasis or skin cancer, where repeated sampling can be conducted without affecting the patient's quality of life.

Furthermore, microneedles also demonstrate unique functions in the fields of cell and gene therapy. By loading mRNA encoding therapeutic proteins or CRISPR-Cas9 gene editing systems into soluble microneedles, they can directly deliver to skin cells. This non-viral delivery method avoids the immunogenicity and integration risks caused by traditional viral vectors. In mouse models, the mRNA vaccine delivered by microneedles successfully induced a strong anti-tumor immune response. Microneedle therapy is evolving from a simple delivery tool to a multifunctional platform that connects basic research with clinical translation, driving the innovation pace of the entire biopharmaceutical industry.