Versatile Prodrug Nanoparticles for Acid‐Triggered Precise Imaging and Organelle‐Specific Combination Cancer Therapy

Integration of chemotherapy with photodynamic therapy (PDT) has been emerging as a novel strategy for treatment of triple negative breast cancer (TNBC). However, the clinical translation of this approach is hindered by the unwanted dark toxicity due to the “always‐on” model and low tumor specificity of currently approved photosensitizer (PS). Here, the design of a multifunctional prodrug nanoparticle (NP) is described for precise imaging and organelle‐specific combination cancer therapy. The prodrug NP is composed of a newly synthesized oxaliplatin prodrug, hexadecyl‐oxaliplatin‐trimethyleneamine (HOT), an acid‐activatable PS, derivative of Chlorin e6 (AC), and functionalized with a targeting ligand iRGD for tumor homing and penetration. HOT displays much higher antitumor efficiency than oxaliplatin by simultaneously inducing mitochondria depolarizing and DNA cross‐linking. AC is specifically activated in the orthotopic or metastatic TNBC tumor for fluorescence imaging and PDT, while it remains inert in blood circulation to minimize the dark toxicity. Under the guide of acid‐activatable fluorescence imaging, PDT and chemotherapy can be synergistically performed for highly efficient regression of TNBC. Taken together, this versatile prodrug nanoplatform could achieve tumor‐specific imaging and organelle‐specific combination therapy, which can provide an alternative option for cancer theranostic.     

A Red Light Activatable Multifunctional Prodrug for Image‐Guided Photodynamic Therapy and Cascaded Chemotherapy

A multifunctional prodrug, designated as TPP‐L‐GEM, is fabricated to realize image‐guided in situ tumor photodynamic therapy (PDT) with red light activatable chemotherapy. Gemcitabine is conjugated with a fluorescent photosensitizer, meso‐tetraphenylporphyrin (TPP), by a reactive oxygen species cleavable thioketal linker. Under the irradiation of low‐energy red light, TPP can generate singlet oxygen and damage tumor cells by photodynamic therapy. Simultaneously, the thioketal linkage can be cleaved by singlet oxygen and result in a cascaded gemcitabine release, causing sustained cell damage by chemotherapy. With the combination of PDT and cascaded chemotherapy, TPP‐L‐GEM shows significant tumor therapeutic efficacy in vitro and in vivo. Furthermore, the inherent fluorescent property of TPP endows the TPP‐L‐GEM prodrug with noninvasive drug tracking capability, which is favorable for image‐guided tumor therapy.     

光动力疗法对肝癌小鼠的抗肿瘤及免疫效应研究

目的探讨光动力疗法(PDT)对肿瘤组织杀伤作用及免疫效应的机理。方法应用PDT对40只接种H22肝癌的昆明小鼠作杀伤实验,对组织形态学、抑瘤率及免疫学指标进行检测。结果PDT对肿瘤细胞具有选择性杀伤和抑制肿瘤组织生长的作用,激光照射5天与对照组瘤重分别为(0.760±0.613)g,(1.951±0.822)g;肿瘤体积为(1.648±0.683)cm3,(3.976±0.847)cm3,t=5.856,8.973,P<0.01,两组差异有非常显著性。对正常组织无损伤。各免疫指标与对照组差异有显著性。结论PDT具有直接杀伤癌细胞、抑制肿瘤组织生长的作用,并且对荷瘤小鼠的免疫功能有调节作用。     

Red Blood Cell‐Facilitated Photodynamic Therapy for Cancer Treatment

Photodynamic therapy (PDT) is a promising treatment modality for cancer management. So far, most PDT studies have focused on delivery of photo­sensitizers to tumors. O₂, another essential component of PDT, is not artificially delivered but taken from the biological milieu. However, cancer cells demand a large amount of O₂ to sustain their growth and that often leads to low O₂ levels in tumors. The PDT process may further potentiate the oxygen deficiency, and in turn, adversely affect the PDT efficiency. In the present study, a new technology called red blood cell (RBC)‐facilitated PDT, or RBC‐PDT, is introduced that can potentially solve the issue. As the name tells, RBC‐PDT harnesses erythrocytes, an O₂ transporter, as a carrier for photosensitizers. Because photosensitizers are adjacent to a carry‐on O₂ source, RBC‐PDT can efficiently produce ¹O₂ even under low oxygen conditions. The treatment also benefits from the long circulation of RBCs, which ensures a high intraluminal concentration of photosensitizers during PDT and hence maximizes damage to tumor blood vessels. When tested in U87MG subcutaneous tumor models, RBC‐PDT shows impressive tumor suppression (76.7%) that is attributable to the codelivery of O₂ and photosensitizers. Overall, RBC‐PDT is expected to find wide applications in modern oncology.     

结肠癌的光动力治疗及在体成像研究

探讨新型酞菁类光敏剂T1介导的光动力诊断(PD D)和光动力治疗(PDT)结肠癌的效果,体 外实验检测了光敏剂T1的荧光光谱和吸收光谱(200－800nm),MTT法 检测了T1介导的光动力治疗2种 结肠癌细胞(CT-26、LoVo)和1种正常细胞(成纤维细胞L929)的效果。取雄性BALB/c裸 鼠30只, 建立动物肿瘤模型,随机分成正常对照组、肿瘤模型组、PDD组,每组10只,采用荧光分光光度计检 测光谱图。结果表明T1的体外吸收光谱的最大吸收峰值位于近红外光区,符合酞菁类化合物 的特征; T1在有光照时,T1-PDT对成纤维细胞的影响较小,但T1-PDT能明显抑制结肠癌细胞的增殖 。光谱图 表明,正常对照组的光谱曲线更为平滑,吸收强度比肿瘤模型组的吸收强度弱很多。肿瘤模 型组和PDD 组之间的光谱曲线大致平行,但是两组之间的波峰峰值略有差异,肿瘤模型组吸收强度要低 于PDD组。 T1光敏剂对结肠癌的光动力治疗及诊断均有明显效果,这种联合应用将有可能为临床早期结 肠癌的诊治提供新的途径。     

肿瘤的光动力诊断和光动力治疗的研究进展

HPD等光敏化剂可以有选择地潴留在肿瘤内，激光诱导出的特征光谱可用于肿瘤的光动力诊断。当用一定波长的激光照射光敏物质分子时，它可以从基态跃迁激发单态，通过系际交叉过渡到激发三重态。处于三重态的光敏化剂分子通过能量转移，使三重态的氧变成对肿瘤细胞具有毒化作用的单态氧，从而实现了肿瘤的光动力治疗。     

光动力疗法对荷瘤小鼠生存期的影响

目的探讨光动力疗法对肿瘤的杀伤效应、机制及其对荷瘤小鼠生存期的影响.方法应用光动力疗法作用于15只接种Louis肺癌的昆明小鼠,对照观察其生存期.结果两组小鼠生存分析曲线差异有显著性,P<0.05,实验组荷瘤鼠平均生存时间为33.79天,对照组为24.14天.结论进一步证明光动力疗法对肿瘤组织具有杀伤和抑制作用,可延长实验组荷瘤鼠的生存期,为将其应用于临床治疗恶性肿瘤提供依据.     

光动力疗法对Louis肺癌鼠的杀伤及免疫效应

应用光动力疗法对 30只接种Louis肺癌瘤株的昆明小鼠作杀伤实验研究。对实验组与对照组荷瘤鼠抑瘤曲线、抑瘤率及免疫学指标进行检测。结果表明 ,两组肿瘤生长曲线存在明显差异 (P<0 0 5 )。两组肿瘤生长体积和肿瘤重量均存在明显差异 (P <0 0 1)。实验组瘤体积抑制率为 5 2 94 % ,瘤重量抑制率为 37 2 4 %。各免疫指标与对照组差异有显著性。说明光动力疗法对肿瘤细胞具有杀伤和抑制生长作用 ,并且对荷瘤小鼠的免疫功能有调节作用     

光动力治疗对荷瘤小鼠肿瘤淋巴细胞表型的影响

目的:观察光动力治疗(PDT)肿瘤留置对残存肿瘤局部淋巴细胞表型的影响。方法:采用双侧小鼠荷H22移植型肝癌模型。将30只双侧荷瘤小鼠分为3组:PDT组,切除组,对照组。光动力治疗一侧肿瘤后,定量观察残存肿瘤和脾脏内CD4+和CD8+细胞的变化。使用免疫组织化学及图像分析技术。结果:在原位肿瘤内,有极少量的CD4+细胞。在残存肿瘤内,未见CD4+细胞,CD8+细胞呈明显的带状分布,在光动力治疗组,CD8+细胞的密度明显增高,但仍不足以杀死残存肿瘤,其活性也有待进一步研究。     

A NIR-II Fluorescent PolyBodipy Delivering Cationic Pt-NHC with Type II Immunogenic Cell Death for Combined Chemotherapy and Photodynamic Immunotherapy

Tumor immunotherapy has emerged as one of the most promising clinical techniques to treat cancer tumors. Despite its clinical application, the cancerous immunosuppressive microenvironment limits the therapeutic efficiency of the treatment. To generate a stronger immunogenic therapeutic effect, herein, a platinum complex for chemotherapy and a BODIPY photosensitizer for photodynamic therapy are encapsulated into multimodal type II immunogenic cell death (ICD) induce nanoparticles. As the platinum complex and the photosensitizer are able to induce type II ICD, an exceptionally strong immune response is observed in triple-negative breast cancer cells. While remaining stable and therefore poorly cytotoxic in the dark, the nanomaterial is found to quickly dissociate upon exposure to near-infrared light, causing a multimodal mechanism of action in cancer cells as well as multicellular tumor spheroids through combined chemotherapy, photodynamic therapy, and immunotherapy. The nanoparticles are found to nearly fully eradicate a triple-negative breast cancer tumor and therefore to strongly enhance the survival of tumor-bearing mice models using low drug and light doses.     

Reactive Oxygen Species–Activatable Liposomes Regulating Hypoxic Tumor Microenvironment for Synergistic Photo/Chemodynamic Therapies

Tumors have adapted various cellular antidotes and microenvironmental conditions to subsist against photodynamic therapy (PDT) and chemodynamic therapy (CDT). Here, the development of reactive oxygen species (ROS)‐activatable liposomes (RALP) for therapeutic enhancement by simultaneously addressing the critical questions in PDT and CDT is reported. The design of RALP@HOC@Fe₃O₄ features ROS‐cleavable linker molecules for improved tumor penetration/uptake and ondemand cargo releasing, and integration of Fe₃O₄ and an oxaliplatin prodrug for smart regulation of hypoxia tumor microenvironment. Glutathione stored by the tumor cells is consumed by the prodrug to produce highly toxic oxaliplatin. Depletion of glutathione not only avoids the undesired annihilation of ROS in PDT, but also modulates the chemical specie equilibria in tumors for H₂O₂ promotion, leading to greatly relieved tumor hypoxia and PDT enhancement. Synergistically, Fe (II) in the hybrid RALP formulation can be fuelled by H₂O₂ to generate ?OH in the Fenton reaction, thus elevating CDT efficiency. This work offers a strategy for harnessing smart, responsive, and biocompatible liposomes to enhance PDT and CDT by regulating tumor microenvironment, highlighting a potential clinical translation beneficial to patients with cancer.     

用光谱法研究光敏剂血卟啉单甲醚对肿瘤细胞光动力作用的分子机制

测定了光敏剂血卟啉单甲醚对人宫颈癌细胞HeLa光敏作用后的傅里叶红外光谱。结果显示:光敏作用后,HeLa细胞磷酸二酯基团的对称伸缩振动峰1085cm^-1和不对称伸缩振动峰1246cm^-1蓝移,强度下降:蛋白质酰胺Ⅰ带1656cm^-1发生蓝移,酰胺Ⅱ带1546cm^-1出现红移;CH₂对称伸缩振动峰2858cm^-1,峰位蓝移2cm^-1,峰值明显减弱:细胞的蛋白质和核酸谱峰面积比值D1085/D1546降低。提示细胞中的DNA、蛋白质和磷脂结构受到损伤。结果表明:DNA、蛋白质和磷脂是血卟啉单甲醚光敏作用的主要靶分子。     

血卟啉单甲醚-光动力疗法对Bcl-2的作用

体外研究表明,光动力疗法(PDT)主要是通过诱导细胞凋亡达到杀死细胞的目的。Bcl-2可以抑制凋亡的发生。为了研究血卟啉单甲醚(HMME)光动力诱导的HeLa细胞凋亡对Bcl-2的作用,收集照射(15mW／cm^2,5．4J／cm^2)后0、2、4、6h的细胞,用半胱氨酸天冬氨酸特异性蛋白酶(caspase-3)的活性表征细胞凋亡的发生;通过western杂交检测PDT处理后细胞内Bcl-2含量的变化。研究发现,PDT处理后与0h相比,2、4、6h后caspase-3的活性有增高的趋势,但Bcl-2的含量没有明显的变化。     

MPPA光动力作用诱导人鼻咽癌细胞凋亡的实验研究

为观察MPPa光动力作用对鼻咽癌细胞凋亡的影响,应用AnnexinV—PI双染结合流式细胞仪分析MPPa光动力作用后人鼻咽癌细胞株CNE2细胞发生凋亡和继发性坏死的比率。结果显示MPPa光动力作用实验组人鼻咽癌细胞株CNE2细胞发生凋亡和继发性坏死的比率分别增加到16.43 %和4.64 % ,且均显著高于单纯光照射组、单纯MMPa光敏剂处理组和假照射组(P <0 .0 1) ,而三对照组间无明显差异(P >0 .0 5 )。表明MPPa光动力作用能有效诱导低分化人鼻咽癌细胞株CNE2细胞凋亡的发生。这也可能是MPPa光动力作用杀伤鼻咽癌的重要机制之一。     

基于ALA的PDT体外灭活HL60实验研究

利用自行设计的光动力疗法(PDT)反应室对HL60细胞进行了氨乙酰丙酸(ALA)PDT实验研究，获得灭活HL60细胞的最佳光学参量因子：ALA培养的终浓度为1．0mM／ml；ALA的培养时间为4h；辐射光波长为412nm；辐照光剂量为18J／cm^2；辐照光功率为5mW／cm^2；培养细胞的胎牛血清(FCS)浓度为8％～10％。在这些光学参数下对HL60的灭活能达89．9％，而单核淋巴细胞(PBMC)的损伤仅为15％，基本上能达到选择性地灭活肿瘤细胞HL60。     

CPD5的光动力作用及维生素C抗光毒效果

采用细胞排染试验,观察CPD5对人胰癌细胞（Hs766T）的体外光动力疗法（PDT）作用及维生素C减轻光毒的效果。结果表明：1）人胰癌细胞对CPD5 PDT敏感,在CPD5浓度为2．5μg／mL时。PDT造成胰癌细胞抑制率达97．4％;2）浓度为40μg／mL的维生素C有明显的减轻光毒作用,最高可使细胞存活率提高86．0％。     

Highly Biocompatible Carbon Nanodots for Simultaneous Bioimaging and Targeted Photodynamic Therapy In Vitro and In Vivo

Photosensitizers (PSs) are light‐sensitive molecules that are highly hydrophobic, which poses a challenge to their use for targeted photodynamic therapy. Hence, considerable efforts have been made to develop carriers for the delivery of PSs. Herein, a novel design is described of highly biocompatible, fluorescent, folic acid (FA)‐functionalized carbon nanodots (CDs) as carriers for the PS zinc phthalocyanine (ZnPc) to achieve simultaneous biological imaging and targeted photodynamic therapy. FA is modified on PEG‐­passivated CDs (CD‐PEG) for targeted delivery to FA‐positive cancer cells, and ZnPc is loaded onto CD‐PEG‐FA via π–π stacking interactions. CD‐PEG‐FA/ZnPc exhibits excellent targeted delivery of the PS, leading to simultaneous imaging and significant targeted photodynamic therapy after irradiation in vitro and in vivo. The present CD‐based targeted delivery of PSs is anticipated to offer a convenient and effective platform for enhanced photodynamic therapy to treat cancers in the near future.     

BPD-MA光动力作用对膀胱癌细胞凋亡及bcl-2蛋白表达的影响

目的:研究激光活化BPD-MA光动力诱导肿瘤细胞凋亡及其可能机制。方法:应用流式细胞仪分析BPD-MA光动力作用后细胞凋亡及免疫组化染色检测凋亡相关蛋白bcl-2蛋白表达水平。结果:激光活化BPD-MA光动力实验组人膀胱癌细胞株BIU-87凋亡发生率达26.11±2.59%,与对照组相比,差异非常显著性(P<0.01);光动力作用后膀胱癌细胞线粒体相关调控蛋白bcl-2表达显著低于对照组(P<0.05)。结论:激光活化BPD-MA光动力作用具有诱导人膀胱癌细胞株BIU-87凋亡的生物效应,而线粒体相关调控蛋白bcl-2表达水平的降低可能是激光活化BPD-MA光动力诱导人膀胱癌细胞株BIU-87凋亡的重要机制之一。     

Intranuclear Photosensitizer Delivery and Photosensitization for Enhanced Photodynamic Therapy with Ultralow Irradiance

Photodynamic therapy (PDT) is a well‐established clinical treatment modality for various diseases. However, reactive oxygen species (ROS) generated by photosensitizers(PS) under proper irradiation exhibits the extremely short life span (<200 ns) and severely limited diffusion distance (20 nm), so the damage of ROS to biomolecules, especially DNA, is strongly confined to the immediate vicinity of ROS generation. In this report, an efficient nuclear‐targeted delivery strategy is proposed by using TAT and RGD peptides co‐conjugated mesoporous silica nanoparticles (MSNs) as PS carriers. The conjugation of TAT peptides enable the nuclear penetration of MSNs for efficient accumulation of PS inside nuclei. The intranuclear‐accumulated PS can generate ROS upon irradiation right inside nuclei to destroy DNA instantaneously. For the purpose of in vivo applications, the co‐conjugated RGD peptides endow the nuclear‐targeted delivery system with specific binding and recognition to tumor vasculature and tumor cell membranes for significantly enhanced specificity and reduced side effects. Through intravenous injection of these nanosystems in tumor‐bearing mice at a rather low PS dose of 2 mg/kg, tumor growth is efficiently inhibited by an extremely low irradiation dose of 6 J/cm². This work presents a new paradigm for specific PDT with high efficacy and low side effects in vivo.