Hypoxia commonly occurs within tumours and is a major cause of radiotherapy resistance. Clinical outcomes could be improved by locating and selectively increasing the dose delivered to hypoxic regions. Here we describe a miniature implantable sensor for real-time monitoring of tissue oxygenation that could enable this novel treatment approach to be implemented. The sensor uses a solid-state electrochemical cell that was microfabricated at wafer level on a silicon substrate, and includes an integrated reference electrode and electrolyte membrane. It gave a linear response to oxygen concentration, and was unaffected by sterilisation and irradiation, but showed susceptibility to biofouling. Oxygen selectivity was also evaluated against various clinically relevant electroactive compounds. We investigated its robustness and functionality under realistic clinical conditions using a sheep model of lung cancer. The sensor remained functional following CT-guided tumour implantation, and was sufficiently sensitive to track acute changes in oxygenation within tumour tissue.

缺氧通常发生在肿瘤内，是放疗抵抗的主要原因。通过定位并有选择地增加向缺氧区域的剂量，可以改善临床效果。在这里，我们描述了一种用于组织氧合实时监测的微型植入式传感器，它可以使这种新颖的治疗方法得以实施。该传感器使用固态电化学电池，该电池在晶片级别上被微细加工在硅基板上，并包括集成的参比电极和电解质膜。它对氧气浓度具有线性响应，并且不受灭菌和辐照的影响，但对生物污染表现出敏感性。还针对各种临床相关的电活性化合物评估了氧气的选择性。我们使用绵羊的肺癌模型在现实的临床条件下研究了它的鲁棒性和功能性。该传感器在CT引导的肿瘤植入后仍保持功能，并且足够灵敏以追踪肿瘤组织内氧合的急性变化。