A Ternary Synergistic eNOS Gene Delivery System Based on Calcium Ion and L-Arginine for Accelerating Angiogenesis by Maximizing NO Production.

Purpose: This study aimed to construct a delivery system based on L-arginine-modified calcium phosphate (CaP) to load eNOS plasmids (peNOS), which could amply nitric oxide (NO) to repair endothelial damage, promote angiogenic activities and alleviate inflammation. Methods: pDNA-loaded CaP nanocomplex (CaP/pDNA) were prepared by co-precipitation method, subsequently modified by L-arginine. The gene transfection efficiency, pro-angiogenic and anti-inflammatory ability were investigated in vivo and in vitro. The therapeutic effect on ischemic hindlimb in vivo was assessed. Results: L-arginine modification augmented the transfection efficiency of CaP/peNOS to elevate the eNOS expression, and then served as NO substrate catalyzed by eNOS. At the same time, calcium ions produced by degradation of CaP carriers enhanced the activity of eNOS. In vitro experiments, the loading capability and transfection performance of R(L)-CaP were confirmed to be superior to that of CaP. Additionally, HUVECs treated with R(L)-CaP/peNOS showed the strongest NO release, cell migration, tube formation and the lowest inflammatory levels compared to the CaP/peNOS and R(D)-CaP/peNOS groups. We also demonstrated the advantages of R(L)-CaP/peNOS in increasing blood reperfusion in hindlimb ischemia mice by accelerating angiogenesis and reducing inflammation, which can be attributed to the highest eNOS-derived NO production. Conclusion: The combination strategy of peNOS transfection, L-arginine supplement and calcium ions addition is a promising therapeutic approach for certain vascular diseases, based on the synergistic NO production.

Tumor Microenvironment-triggered Nanosystems as dual-relief Tumor Hypoxia Immunomodulators for enhanced Phototherapy.

Photodynamic therapy (PDT) is a promising strategy in cancer treatment that utilizes photosensitizers (PSs) to produce reactive oxygen species (ROS) and eliminate cancer cells under specific wavelength light irradiation. However, special tumor environments, such as those with overexpression of glutathione (GSH), which will consume PDT-mediated ROS, as well as hypoxia in the tumor microenvironment (TME) could lead to ineffective treatment. Moreover, PDT is highly light-dependent and therefore can be hindered in deep tumor cells where light cannot easily penetrate. To solve these problems, we designed oxygen-dual-generating nanosystems MnO2@Chitosan-CyI (MCC) for enhanced phototherapy. Methods: The TME-sensitive nanosystems MCC were easily prepared through the self-assembly of iodinated indocyanine green (ICG) derivative CyI and chitosan, after which the MnO2 nanoparticles were formed as a shell by electrostatic interaction and Mn-N coordinate bonding. Results: When subjected to NIR irradiation, MCC offered enhanced ROS production and heat generation. Furthermore, once endocytosed, MnO2 could not only decrease the level of GSH but also serve as a highly efficient in situ oxygen generator. Meanwhile, heat generation-induced temperature increase accelerated in vivo blood flow, which effectively relieved the environmental tumor hypoxia. Furthermore, enhanced PDT triggered an acute immune response, leading to NIR-guided, synergistic PDT/photothermal/immunotherapy capable of eliminating tumors and reducing tumor metastasis. Conclusion: The proposed novel nanosystems represent an important advance in altering TME for improved clinical PDT efficacy, as well as their potential as effective theranostic agents in cancer treatment.

Targeted nanocarriers based on iodinated-cyanine dyes as immunomodulators for synergistic phototherapy.

Photodynamic therapy (PDT), as one of the most powerful photo-therapeutic strategies for cancer treatment with minimum invasiveness, can effectively damage local tumor cells and significantly induce systemic antitumor immunity. However, current nanotechnology-assisted PDT-immunomodulators have either poor penetration for deep tumors or low singlet oxygen generation. Herein, we construct a novel theranostic nanocarrier (HA-PEG-CyI, HPC) by inducing the self-assembly of PEGylated CyI and attaching the ligand HA to its surface. The prepared HPC can be used as an ideal PDT-immunomodulator for synergistic cancer therapy. CyI is an iodinated-cyanine dye with enhanced singlet oxygen generation ability as well as excellent photo-to-photothermal and near-infrared fluorescence imaging properties. Under 808 nm laser irradiation, the prepared HPC can generate both reactive oxygen species (ROS) and elevate temperature which can subsequently result in apoptosis and necrosis at tumor sites. Moreover, the HPC-induced cell death can generate a series of acute inflammatory reactions, leading to systemic immunity induction and secondary death of tumor cells, which further results in reducing tumor recurrence. In vitro and in vivo results show that HPC can enhance the tumor targeting efficacy, generate ROS efficiently and exhibit a high temperature response under NIR irradiation, which working together can activate immune responses for synergistic phototherapy on tumor cells. Accordingly, the proposed multi-functional HPC nanocarriers represent an important advance in PDT and can be used as a superior cancer treatment strategy with great promise for clinical applications.

NIR-guided dendritic nanoplatform for improving antitumor efficacy by combining chemo-phototherapy.

BACKGROUND: Phototherapy, including photothermal therapy (PTT) and photodynamic therapy (PDT), is a promising noninvasive strategy in the treatment of cancers due to its highly localized specificity to tumors and minimal side effects to normal tissues. However, single phototherapy often causes tumor recurrence which hinders its clinical applications. Therefore, developing a NIR-guided dendritic nanoplatform for improving the phototherapy effect and reducing the recurrence of tumors by synergistic chemotherapy and phototherapy is essential. METHODS: A fluorescent targeting ligand, insisting of ICG derivative cypate and a tumor penetration peptide iRGD (CRGDKGPDC), was covalently combined with PAMAM dendrimer to prepare a single agent-based dendritic theranostic nanoplatform iRGD-cypate-PAMAM-DTX (RCPD). RESULTS: Compared with free cypate, the resulted RCPD could generate enhanced singlet oxygen species while maintaining its fluorescence intensity and heat generation ability when subjected to NIR irradiation. Furthermore, our in vitro and in vivo therapeutic studies demonstrated that compared with phototherapy or chemotherapy alone, the combinatorial chemo-photo treatment of RCPD with the local exposure of NIR light can significantly improve anti-tumor efficiency and reduce the risk of recurrence of tumors. CONCLUSION: The multifunctional theranostic platform (RCPD) could be used as a promising method for NIR fluorescence image-guided combinatorial treatment of tumor cancers.

Iodinated Cyanine Dyes for Fast Near-Infrared-Guided Deep Tissue Synergistic Phototherapy.

Phototheranostics, which combines deep tissue imaging and phototherapy [photodynamic therapy (PDT) and/or photothermal therapy (PTT)] via light irradiation, is a promising strategy to treat tumors. Near-infrared (NIR) cyanine dyes are researched as potential phototheranostics reagents for their excellent photophysical properties. However, the low singlet oxygen generation efficiency of cyanine dyes often leads to inadequate therapeutic efficacy for tumors. Herein, we modified an indocyanine green derivative Cy7 with heavy atom iodine to form a novel NIR dye CyI to improve the reactive oxygen species (ROS) production and heat generation while, at the same time, maintain their fluorescence characteristics for in vivo noninvasive imaging. More importantly, in vitro and in vivo therapeutic results illustrated that CyI could quickly and simultaneously generate enhanced ROS and heat to induce more cancer cell apoptosis and higher inhibition rates in deep HepG2 tumors than other noniodinated NIR dyes upon NIR irradiation. Besides, low toxicity of the resulted iodinated NIR dyes was confirmed by in vivo biodistribution and acute toxicity. Results indicate that this low toxic NIR dye could be an ideal phototheranostics agent for deep tumor treatments. Our study presents a novel approach to achieve the fast-synergistic PDT/PTT treatment in deep tissues.

Graft copolymer nanoparticles with pH and reduction dual-induced disassemblable property for enhanced intracellular curcumin release.

Nanoparticle (NP)-assisted drug delivery systems with disassemblable behaviors in response to intracellular microenvironment are urgently demanded in systemic cancer chemotherapy for enhanced intracellular drug release. Curcumin (CUR), an effective and safe anticancer agent, was limited by its water insolubility and poor bioavailability. Herein, pH and reduction dual-induced disassemblable NPs for high loading efficiency and improved intracellular release of CUR were developed based on an acid degradable cyclic benzylidene acetal groups (CBAs)-functionalized poly(2,4,6-trimethoxybenzylidene-1,1,1-tris(hydroxymethyl)ethane methacrylate)-g-SS-poly(ethylene glycol) (PTTMA-g-SS-PEG) graft copolymer, which was readily prepared via RAFT copolymerization and coupling reaction. The NPs self-assembled from PTTMA-g-SS-PEG copolymers were stable at physiological pH, and quickly disassembled in mildly acidic and reductive environments because of the hydrolysis of CBAs in hydrophobic PTTMA core and the cleavage of disulfide-linked detachable PEG shell. PTTMA-g-SS-PEG NPs exhibited excellent CUR loading capacity with drug loading content up to 19.2% and entrapment efficiency of 96.0%. Within 20 h in vitro, less than 15.0% of CUR was released from the CUR-loaded NPs in normal physiological conditions, whereas 94.3% was released in the presence of reductive agent and mildly acidic conditions analogous to the microenvironment in endosome/lysosome and cytoplasm. Confocal fluorescence microscopies revealed that the CUR-loaded PTTMA-g-SS-PEG NPs exhibited more efficiently intracellular CUR release for EC-109 cells than that of CUR-loaded reduction-unresponsive PTTMA-g-PEG NPs and free CUR. In vitro cytotoxicity studies displayed blank PTTMA-g-SS-PEG NPs showed low toxicity at concentrations up to 1.0 mg/mL, whereas CUR-loaded PTTMA-g-SS-PEG NPs demonstrated more efficient growth inhibition toward EC-109 and HepG-2 cells than reduction-unresponsive controls and free CUR. Therefore, the above results indicated that pH and reduction dual-induced disassemblable PTTMA-g-SS-PEG NPs may have emerged as superior nanocarriers for active loading and promoted intracellular drug delivery in systemic cancer chemotherapy.