关键词: 微针, 透皮技术, 工作原理, 医学应用, 未来发展

Abstract: Microneedles are micrometer sized single needles or needle arrays that are produced by microfabricating techniques. Microneedles could penetrate the stratum corneum layer of the skin to reach the dermal layer which is favorable for percutaneous drug delivery. Microneedles have a number of advantages in drug delivery, compared with oral administration, microneedles circumvent the metabolic effects of the digestive system on drugs, compared with injection needles, microneedles are able to reduce pain and improve adherence compliance in patients. Due to their special transdermal pathway and precise, convenient application methods, microneedle has also become a hot studies area in biomedicine at present and their applications in vaccination, tissue fluid extraction and biomarker detection, etc. have been well investigated. According to working mechanisms for percutaneous drug delivery, microneedles can be classified as five kinds, including solid, coated, dissolving, hollow, and hydrogel microneedles. This review, combined with relevant articles in the field of microneedle technology in recent years, provides a brief overview of the types and fabricating materials of microneedles, mainly introduces the current applications of microneedles in the field of drug delivery (such as insulin injection for diabetes treatment, local drug delivery for cancer treatment, vaccination, tissue fluid extraction and biomarker detection, etc.) Besides, if the microneedles would be widely applied in the marker for medical application, some factors including mechanic strength, biological safety, sterilization process and biological stability of biomolecules on the micrneedles should be well considered which are also discussed in the review. At last, outlooks on microneedles' future development are prospected, such as developing microneedles based drug delivery system for heart attack treatment, improving biological stability of the biological molecules on the microneedles for convenient vaccination, and combining of microneedles with other techniques, such as sensitive biomarker detection method, microfluidic chip and wearable device, which will open a new prospect for the development of microneedles techniques.

Key words: microneedle, transdermal technology, working mechanism, medical application, future development