Saeid Sama, Pitkanen Marja, Ilonen Emma, Niskanen Jukka, Tenhu Heikki, Vinberg Frans, Koskelainen Ari
IEEE Trans Biomed Eng. 2025 Apr;72(4):1256-1265. doi: 10.1109/TBME.2024.3493616. Epub 2025 Mar 20.
The isolated mammalian retina may serve as a sensitive biosensor for preclinical drug testing, including eye drugs and a broader range of pharmaceuticals. To facilitate testing with minimal amounts of drug molecules or nanostructures, we developed a closed-perfusion transretinal electroretinography (tERG) setup.
The major challenge with small amounts of circulating perfusate was maintaining retinal viability and stability during long experiments. We conducted ex vivo tERG using WT C57BL/6J and mice to assess rod- and cone-mediated light signals. The dark-adapted retina was stimulated with full-field light flashes while perfused at 5-6 ml/min.
The minimum perfusate needed in our closed-circulation was around 50 ml. Penicillin-Streptomycin (Pen-Strep) was indispensable for long recordings. Rod responses remained stable for at least 42 hours, the longest recording we conducted, with the retina still responsive, and rod and cone bipolar cell responses for up to 12 hours. IBMX (3-isobutyl-1-methylxanthine), a non-specific phosphodiesterase (PDE) inhibitor with reversible effects, validated our setup. We used our setup to test the zwitterionic polymer poly(sulfobetaine methacrylate) (PSMBA), serving as a promising material for thermoresponsive nanostructures, and the corresponding monomer SBMA for possible harmful effects on mouse rod and bipolar cell functioning.
Our closed-perfusion tERG setup enables long experiments with small amounts of perfusate. PSMBA or SBMA had no effect on rod and bipolar cell responses.
This method is applicable for assessing drug functionality, as well as conducting preliminary biocompatibility and toxicity testing using small amounts of molecules or nanostructures that could impact neuronal or synaptic function.
分离的哺乳动物视网膜可作为临床前药物测试的灵敏生物传感器，包括眼科药物和更广泛的药物。为便于使用极少量的药物分子或纳米结构进行测试，我们开发了一种封闭式灌注经视网膜电图（tERG）装置。
少量循环灌注液面临的主要挑战是在长时间实验中维持视网膜的活力和稳定性。我们使用野生型C57BL/6J小鼠进行离体tERG，以评估视杆和视锥介导的光信号。在暗适应的视网膜以5 - 6毫升/分钟的速度灌注时，用全视野闪光进行刺激。
我们的闭路循环所需的最小灌注液量约为50毫升。青霉素 - 链霉素（Pen - Strep）对于长时间记录是必不可少的。视杆反应在我们进行的最长记录中至少42小时保持稳定，视网膜仍有反应，视杆和视锥双极细胞反应可持续长达12小时。3 - 异丁基 - 1 - 甲基黄嘌呤（IBMX），一种具有可逆作用的非特异性磷酸二酯酶（PDE）抑制剂，验证了我们的装置。我们使用该装置测试了两性离子聚合物聚（甲基丙烯酸磺酸甜菜碱）（PSMBA），它是一种有前景的热响应纳米结构材料，以及相应的单体SBMA对小鼠视杆和双极细胞功能可能的有害影响。
我们的封闭式灌注tERG装置能够使用少量灌注液进行长时间实验。PSMBA或SBMA对视杆和双极细胞反应没有影响。
该方法适用于评估药物功能，以及使用可能影响神经元或突触功能的少量分子或纳米结构进行初步的生物相容性和毒性测试。
