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Oxygen-Self-Produced Nanoplatform for Relieving Hypoxia and Breaking Resistance to Sonodynamic Treatment of Pancreatic Cancer Jie Chen,†,# Honglin Luo,†,# Yan Liu,† Wei Zhang,† Hongxue Li,† Tao Luo,† Kun Zhang,*,†,‡ Yongxiang Zhao,*,†,§ and Junjie Liu*,† Downloaded via UNIV OF CALIFORNIA SANTA BARBARA on June 28, 2018 at 21:29:33 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
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Affiliated Tumor Hospital of Guangxi Medical University, 71 He-di Road, Nanning 530021, People’s Republic of China Department of Medical Ultrasound, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, 301 Yan-chang-zhong Road, Shanghai 200072, People’s Republic of China § National Center for International Research of Biological Targeting Diagnosis and Therapy, Guangxi Key Laboratory of Biological Targeting Diagnosis and Therapy Research, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, 6 Shuang-yong Road, Nanning, Guangxi 530021, People’s Republic of China ‡
S Supporting Information *
ABSTRACT: Hypoxia as one characteristic hallmark of solid tumors has been demonstrated to be involved in cancer metastasis and progression, induce severe resistance to oxygen-dependent therapies, and hamper the transportation of theranostic agents. To address these issues, an oxygen-self-produced sonodynamic therapy (SDT) nanoplatform involving a modified fluorocarbon (FC)chain-mediated oxygen delivery protocol has been established to realize highly efficient SDT against hypoxic pancreatic cancer. In this nanoplatform, mesopores and FC chains of FC-chain-functionalized hollow mesoporous organosilica nanoparticle carriers can provide sufficient storage capacity and binding sites for sonosensitizers (IR780) and oxygen, respectively. In vitro and in vivo experiments demonstrate the nanoplatform involving this distinctive oxygen delivery protocol indeed breaks the hypoxia-specific transportation barriers, supplies sufficient oxygen to hypoxic PANC-1 cells especially upon exposure to ultrasound irradiation, and relieves hypoxia. Consequently, hypoxiainduced resistance to SDT is inhibited and sufficient highly reactive oxygen species (ROS) are produced to kill PANC-1 cells and shrink hypoxic PANC-1 pancreatic cancer. This distinctive FC-chain-mediated oxygen delivery method provides an avenue to hypoxia oxygenation and holds great potential in mitigating hypoxia-induced resistance to those oxygendepleted therapies, e.g., photodynamic therapy, radiotherapy, and chemotherapy. KEYWORDS: hypoxia reversion, oxygen delivery, sonodynamic treatment, reactive active species, hypoxia-induced resistance
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associated with hypoxia, e.g., inadequate blood supply, reduced susceptibility, drug-resistant gene expression, and deficiency in targeting sites, remain unresolved in these two pathways. As a comparison, tumor oxygenation has aroused considerable attention, since it can effectively relieve hypoxia microenvironment via delivering oxygen to hypoxic regions of solid tumor and further attenuate resistance to various oxygen-dependent therapies.12−15 Currently, various oxygen-delivery strategies have been designed to modulate tumor hypoxia to reinforce radiotherapy and PDT, e.g., hyperbaric oxygen (HBO) injection,16 oxygen-
nsufficient oxygen supply termed hypoxia ubiquitously arises in various solid tumors and can be recognized as one characteristic hallmark of advanced solid tumors.1 It has been extensively accepted that hypoxia can promote tumor angiogenesis and cancer metastasis.2−6 Moreover, the hostile hypoxia also leads to some inherent resistances to medical therapies (e.g., radiotherapy, chemotherapy, and photodynamic therapy (PDT)) wherein oxygen is essential in the process of cancer cell destruction, consequently resulting in the failures of many antitumor technologies.1,5 Therefore, protocols capable of relieving or even reversing hypoxia is desirable but challenging. In an attempt to treat hypoxic tumor, two pathways are highlighted, one of which is to develop a less oxygen-dependent therapy or hypoxia-activated prodrugs.7−10 In practice, the two methods fail to truly alter the pre-existing hypoxia.11 As a consequence, the intrinsic characteristics © 2017 American Chemical Society
Received: November 20, 2017 Accepted: December 13, 2017 Published: December 13, 2017 12849
DOI: 10.1021/acsnano.7b08225 ACS Nano 2017, 11, 12849−12862
Article
Cite This: ACS Nano 2017, 11, 12849−12862
Article
ACS Nano
Figure 1. Synthetic process and action principle of IR780@O2-FHMON and characterization of FHMON carriers. (a) Schematic of IR780@ O2-FHMON; (b) principle of intensified SDT using IR780@O2-FHMON; (c−e) TEM, dark-field, bright-field images of FHMON carriers; (f− j) merged atom mapping image (f) and Si (g), C (h), O (i), F (j) atom mapping images of FHMON carriers.
carried microbubbles,12,17,18 in situ oxygen production by reaction between H2O2 and metals or catalase,19−22 photoactivated H2O-splitting-mediated oxygen production,23 and dissolved oxygen delivery in perfluorocarbon (PFC) compounds or hemoglobin.15,24 These strategies have been demonstrated to realize hypoxia oxygenation via high-efficient oxygen delivery, significantly relieve hypoxia, and intensify the oxygen-dependent therapy efficiency against malignancies, providing candidate pathways to inhibiting tumor metastasis and progression. However, these oxygen delivery strategies suffer from some potential issues, e.g., H2O2 dependence in H2O2-mediated oxygen production, side effects in HBO injection, poor light penetration in photoactivated oxygen production, large size and poor stability in microbubblemediated oxygen delivery, etc.16−26 More significantly, some hypoxia-specific transport barriers consisting of inadequate blood supply, increased interstitial fluid pressure, thick stroma barrier, and disabled targeting due to lack of specific receptors hampered these oxygen delivery carriers from entering hypoxic regions of tumor.2,10,27 Therefore, more advanced and effective oxygen delivery strategies capable of breaking hypoxia-specific transport obstacles are urgently needed. In this report, an oxygen-self-produced nanoplatform with a diameter of less than 200 nm has been prepared to modulate hypoxia, attenuate hypoxia-induced resistance to sonodynamic
therapy (SDT), and improve SDT efficiency against highly aggressive and hypoxic PANC-1 pancreatic cancer. Fluorocarbon (FC)-chain-functionalized hollow mesoporous organosilica nanoparticles (HMONs) (FHMONs) that combine the structural and functional advantages of HMONs were employed as the oxygen reservoir and IR780 sonosensitizer carrier, respectively. It is highly expected that FHMON carriers can absorb oxygen via the functionalized FC chain, since the modified FC chains similar to PFC compounds exhibited a strong affinity toward oxygen via the hydrophobic interaction and H bonding.11,28,29 In particular, the oxygen delivery strategy using chelated FC chains instead of a free PFC compound can avoid troublesome loading, leaching, and the short half-life of the superhydrophobic PFC oxygen reservoir and stabilize O2 delivery. It has been extensively accepted that SDT is more preferable than PDT in treating deep tumors due to the deeper penetration of the ultrasound (US) trigger in SDT than light in PDT.26 Nevertheless, SDT also suffers from hypoxia-induced resistance because of its oxygen-depletion treatment principle.17,18 Herein, this oxygen-self-produced SDT nanoplatform can effectively relieve hypoxic regions of PANC-1 solid tumor via the local US-responsive oxygen release, diminish hypoxiainduced resistance to SDT, produce sufficient reactive oxygen species (ROS), and enhance SDT efficiency against PANC-1 12850
DOI: 10.1021/acsnano.7b08225 ACS Nano 2017, 11, 12849−12862
Article
ACS Nano
Figure 2. Characterization and extracellular and intracellular hypoxia modulation of IR780@O2-FHMON. (a) UV−vis spectra of FHMON carrier and IR780@FHMON with a characteristic peak of IR780 at around 780 nm; (b) zeta potentials of FHMON, IR780@FHMON, and IR780@O2-FHMON; (c, d) GC characteristic peak (c) and optical microscopic image (d) of O2 released from IR780@O2-FHMON after heating and US irradiation, respectively; scale bar: 200 μm. (e) Extracellular O2 concentration of hypoxic PANC-1 cells after treatments with different groups, i.e., control, IR780@FHMON, US+IR780@FHMON, IR780@O2-FHMON, and US+IR780@O2-FHMON; data are presented as the mean value ± SD (n = 3). (f) Time-sweep O2 concentration curves of hypoxic PANC-1 cells after treatment with different groups, i.e., control, IR780@FHMON, US+IR780@FHMON, IR780@O2-FHMON, and US+IR780@O2-FHMON; data are presented as the mean value ± SD (n = 3) and significances are obtained via comparing to control. (g) LCSM images of hypoxic PANC-1 cells stained by O2 indicator, i.e., (Ru(dpp)3)Cl2 after treatment with different groups (i.e., control, IR780@FHMON, US+IR780@FHMON, IR780@O2FHMON, and US+IR780@O2-FHMON); scale bar: 40 μm. Note: *, **, and *** represent p < 0.01, 0.005, and 0.001, respectively.
delivery strategy holds great potential in inhibiting metastasis of hypoxic tumor and breaking hypoxia-induced resistance to other oxygen-dependent therapies, e.g., PDT, radiotherapy, and chemotherapy.
solid tumor. Besides triggering the SDT process and oxygen release, US could promote more nanoparticles or drugs entering hypoxic solid tumor via the enhanced permeability mediated by the bubble-mediated cavitation effect.30−34 Inspired by it, the marriage strategy of oxygen bubbles from this nanoplatform and US irradiation is expected to break hypoxia-specific transport barriers and enable more oxygen-selfproduced SDT nanoplatforms to enter hypoxic regions of PANC-1 solid tumor, which further contributes to the intensified SDT. More significantly, the local irradiation and deep penetration of the US trigger, the small particle size (
