Opt Lett. 2023 Aug 1;48(15):3849-3852. doi: 10.1364/OL.497596.
Interstitial photodynamic therapy (I-PDT), which utilizes optical fibers to deliver light for photosensitizer excitation and the elimination of penetration depth limitation, is a promising modality in the treatment of deeply seated tumors or thick tumors. Currently, the excitation domain of the optical fiber is extremely limited, restricting PDT performance. Here, we designed and fabricated a biocompatible polymer optical fiber (POF) with a strongly scattering spherical end (SSSE) for I-PDT applications, achieving an increased excitation domain and consequently excellent in vitro and in vivo therapeutical outcomes. The POF, which was drawn using a simple thermal drawing method, was made of polylactic acid, ensuring its superior biocompatibility. The excitation domains of POFs with different ends, including flat, spherical, conical, and strongly scattering spherical ends, were analyzed and compared. The SSSE was achieved by introducing nanopores into a spherical end, and was further optimized to achieve a large excitation domain with an even intensity distribution. The optimized POF enabled outstanding therapeutic performance of I-PDT in in vitro cancer cell ablation and in vivo anticancer therapy. All of its notable optical features, including low transmission/bending loss, superior biocompatibility, and a large excitation domain with an even intensity distribution, endow the POF with great potential for clinical I-PDT applications.
间质光动力疗法（I-PDT）利用光纤传输光来激发光敏剂并消除穿透深度限制，是治疗深部肿瘤或厚肿瘤的一种很有前途的方法。目前，光纤的激发域极其有限，限制了 PDT 的性能。在这里，我们设计并制造了一种具有强散射球形端（SSSE）的生物相容性聚合物光纤（POF），用于 I-PDT 应用，实现了更大的激发域，从而获得了出色的体外和体内治疗效果。该 POF 采用简单的热拉伸方法拉伸而成，由聚乳酸制成，具有优异的生物相容性。分析并比较了具有不同末端的 POF 的激发域，包括平面、球形、锥形和强散射球形末端。通过在球形端引入纳米孔来实现 SSSE，并进一步优化以实现具有均匀强度分布的大激发域。优化后的 POF 使 I-PDT 在体外癌细胞消融和体内抗癌治疗中的治疗性能非常出色。其所有显著的光学特性，包括低传输/弯曲损耗、优异的生物相容性以及具有均匀强度分布的大激发域，赋予 POF 在临床 I-PDT 应用中的巨大潜力。
