系统评估微针注射入小鼠角膜。
Systematic assessment of microneedle injection into the mouse cornea.
机构信息
The Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
出版信息
Eur J Med Res. 2012 Jun 20;17(1):19. doi: 10.1186/2047-783X-17-19.
BACKGROUND
Corneal intrastromal injection is an important mode of gene-vector application to subepithelial layers. In a mouse model, this procedure is substantially complicated by the reduced corneal dimensions. Furthermore, it may be difficult to estimate the corneal area reached by the volume of a single injection. This study aimed to investigate intrastromal injections into the mouse cornea using different microneedles and to quantify the effect of injecting varying volumes. A reproducible injection technique is described.
METHODS
Forty eyes of 20 129 Sv/J mice were tested. India ink was intrastromally injected using 30° beveled 33 G needles, tri-surface 25° beveled 35 G needles, or hand-pulled and 25° beveled glass needles. Each eye received a single injection of a volume of 1 or 2 μL. Corneoscleral buttons were fixed and flat mounted for computer-assisted quantification of the affected corneal area. Histological assessment was performed to investigate the intrastromal location of the injected dye.
RESULTS
A mean corneal area of 5.0 ± 1.4 mm(2) (mean ± SD) and 7.7 ± 1.4 mm(2) was covered by intrastromal injections of 1 and 2 μL, respectively. The mean percentage of total corneal area reached ranged from 39% to 53% for 1 μL injections, and from 65% to 81% for 2 μL injections. Injections using the 33 G needles tended to provide the highest distribution area. Perforation rates were 8% for 30° beveled 33 G needles and 44% for tri-surface beveled 35 G needles. No perforation was observed with glass needle; however, intrastromal breakage of needle tips was noted in 25% of these cases.
CONCLUSIONS
Intracorneal injection using a 30° beveled 33 G needle was safe and effective. The use of tri-surface beveled 35 G needles substantially increased the number of corneal perforations. Glass needles may break inside the corneal stroma. Injections of 1 μL and 2 μL resulted in an overall mean of 49% and 73% respectively of total corneal area involved.
背景
角膜基质内注射是将基因载体应用于上皮下层的一种重要方式。在小鼠模型中，由于角膜尺寸减小，该过程大大复杂化。此外，很难估计单次注射的体积所到达的角膜面积。本研究旨在使用不同的微针研究小鼠角膜的基质内注射，并定量评估注射不同体积的效果。本文描述了一种可重复的注射技术。
方法
对 20 只 129 Sv/J 小鼠的 40 只眼睛进行了测试。使用 30°斜面 33 G 针、三斜面 25°斜面 35 G 针或手动拉制的 25°斜面玻璃针将印度墨水注入基质内。每只眼睛接受 1 或 2 μL 的单次注射。固定角膜巩膜瓣并进行平面安装，以便通过计算机辅助量化受影响的角膜面积。进行组织学评估以研究注射染料的基质内位置。
结果
1 μL 和 2 μL 注射的平均角膜面积分别为 5.0 ± 1.4 mm2（平均值 ± 标准差）和 7.7 ± 1.4 mm2。1 μL 注射的总角膜面积覆盖率范围为 39%至 53%，2 μL 注射的覆盖率范围为 65%至 81%。使用 33 G 针进行注射的倾向于提供最高的分布面积。30°斜面 33 G 针的穿孔率为 8%，三斜面斜面 35 G 针的穿孔率为 44%。玻璃针未观察到穿孔，但在这些情况下有 25%的玻璃针针尖出现了基质内断裂。
结论
使用 30°斜面 33 G 针进行的角膜内注射是安全有效的。使用三斜面斜面 35 G 针会大大增加角膜穿孔的数量。玻璃针可能会在角膜基质内断裂。1 μL 和 2 μL 注射的总角膜面积分别为 49%和 73%。
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