Mohizin Abdul, Imran Jakir Hossain, Lee Kee Sung, Kim Jung Kyung
School of Mechanical Engineering, Kookmin University, 77 Jeongneung-Ro, Seongbuk-Gu, Seoul, 02707, Republic of Korea.
Department of Mechanical Engineering, Graduate School, Kookmin University, Seoul, 02707, Republic of Korea.
J Biol Eng. 2023 Feb 27;17(1):15. doi: 10.1186/s13036-023-00335-x.
Needle-free jet injection (NFJI) systems enable a controlled and targeted delivery of drugs into skin tissue. However, a scarce understanding of their underlying mechanisms has been a major deterrent to the development of an efficient system. Primarily, the lack of a suitable visualization technique that could capture the dynamics of the injected fluid-tissue interaction with a microsecond range temporal resolution has emerged as a main limitation. A conventional needle-free injection system may inject the fluids within a few milliseconds and may need a temporal resolution in the microsecond range for obtaining the required images. However, the presently available imaging techniques for skin tissue visualization fail to achieve these required spatial and temporal resolutions. Previous studies on injected fluid-tissue interaction dynamics were conducted using in vitro media with a stiffness similar to that of skin tissue. However, these media are poor substitutes for real skin tissue, and the need for an imaging technique having ex vivo or in vivo imaging capability has been echoed in the previous reports.
A near-infrared imaging technique that utilizes the optical absorption and fluorescence emission of indocyanine green dye, coupled with a tissue clearing technique, was developed for visualizing a NFJI in an ex vivo porcine skin tissue.
The optimal imaging conditions obtained by considering the optical properties of the developed system and mechanical properties of the cleared ex vivo samples are presented. Crucial information on the dynamic interaction of the injected liquid jet with the ex vivo skin tissue layers and their interfaces could be obtained.
The reported technique can be instrumental for understanding the injection mechanism and for the development of an efficient transdermal NFJI system as well.
无针喷射注射（NFJI）系统能够将药物可控且靶向地输送到皮肤组织中。然而，对其潜在机制的了解匮乏一直是高效系统开发的主要障碍。主要原因在于，缺乏一种合适的可视化技术，该技术能够以微秒级的时间分辨率捕捉注射流体与组织相互作用的动态过程，这已成为一个主要限制因素。传统的无针注射系统可能在几毫秒内注射流体，为获取所需图像可能需要微秒级的时间分辨率。然而，目前用于皮肤组织可视化的成像技术无法达到这些所需的空间和时间分辨率。先前关于注射流体与组织相互作用动态的研究是在体外介质中进行的，这些介质的硬度与皮肤组织相似。然而，这些介质并不能很好地替代真实的皮肤组织，先前的报告也呼应了对具有离体或体内成像能力的成像技术的需求。
开发了一种近红外成像技术，该技术利用吲哚菁绿染料的光吸收和荧光发射，并结合组织透明化技术，用于在离体猪皮肤组织中可视化无针喷射注射。
给出了通过考虑所开发系统的光学特性和透明化离体样本的力学特性而获得的最佳成像条件。可以获得关于注射液体射流与离体皮肤组织层及其界面动态相互作用的关键信息。
所报道的技术有助于理解注射机制，也有助于开发高效的经皮无针喷射注射系统。
