Oxygen‐Evolving Mesoporous Organosilica Coated Prussian Blue Nanoplatform for Highly Efficient Photodynamic Therapy of Tumors

Abstract

Oxygen (O2) plays a critical role during photodynamic therapy (PDT), however, hypoxia is quite common in most solid tumors, which limits the PDT efficacy and promotes the tumor aggression. Here, a safe and multifunctional oxygen‐evolving nanoplatform is costructured to overcome this problem. It is composed of a prussian blue (PB) core and chlorin e6 (Ce6) anchored periodic mesoporous organosilica (PMO) shell (denoted as PB@PMO‐Ce6). In the highly integrated nanoplatform, the PB with catalase‐like activity can catalyze hydrogen peroxide to generate O2, and the Ce6 transform the O2 to generate more reactive oxygen species (ROS) upon laser irradiation for PDT. This PB@PMO‐Ce6 nanoplatform presents well‐defined core–shell structure, uniform diameter (105 ± 12 nm), and high biocompatibility. This study confirms that the PB@PMO‐Ce6 nanoplatform can generate more ROS to enhance PDT than free Ce6 in cellular level (p < 0.001). In vivo, the singlet oxygen sensor green staining, tumor volume of tumor‐bearing mice, and histopathological analysis demonstrate that this oxygen‐evolving nanoplatform can elevate singlet oxygen to effectively inhibit tumor growth without obvious damage to major organs. The preliminary results from this study indicate the potential of biocompatible PB@PMO‐Ce6 nanoplatform to elevate O2 and ROS for improving PDT efficacy.

Photo-Enhanced Singlet Oxygen Generation of Prussian Blue-Based Nanocatalyst for Augmented Photodynamic Therapy

“…All compositions in the NCs have been approved by the US Food and Drug Administration (FDA). Prussian blue (PB) is selected as the building block due to its imaging function and catalase-like activity for H 2 O 2 decomposition ( Cheng et al., 2014 , Yang et al., 2012 , Yang et al., 2018 ). It is also expected to control the H 2 O 2 decomposition by local temperature variation of PB irradiated with NIR laser because of the photothermal conversion ability of PB NPs.…”

Photodynamic Therapy Based on Nanoscale Metal–Organic Frameworks: From Material Design to Cancer Nanotherapeutics

“…As shown in Figure a, Zhang et al. loaded the PS Ce6 into mesoporous silica (PMO)‐coated PB NPs, and PB@PMO‐Ce6 achieved the combination of MRI‐ and PAI‐guided PDT and PTT . As shown in Figure b, Li et al.…”

“…(c) PB@HA for combined PAI, PDT, and PTT targeting CD44 receptor. The PAI and MRI images in part a are reproduced with permission under the terms of the Creative Commons Attribution License . Copyright 2018, The Authors.…”

Fighting Hypoxia to Improve PDT

“…Two papers utilized Prussian Blue (PB) NPs that are known for their catalase-like activity and were FDA approved for clinical application [118,119]. In the first one, Yang et al [119] described periodic mesoporous organosilica coated with PB NPs and loaded with Ce6. TESPTS (1,4-bis(triethoxysily)propane tetrasulfide was used as organosilica molecule to coat PB NPs.…”