New combination treatment from ROS-Induced sensitized radiotherapy with nanophototherapeutics to fully eradicate orthotopic breast cancer and inhibit metastasis.

Radiotherapy (RT) is one of the most commonly employed approaches in the treatment of malignant tumors and is often combined with radiosensitizers to enhance the therapeutic efficacy for clinical use. For developing a smart therapeutic strategy leveraging local tissue response to photo-mediated reactions and the combination of multiple treatment modalities involving ROS-induced sensitization of RT, a novel nanophototherapeutic system has been developed. The nanotherapeutics prepared from the assembly of poly (thiodiethylene malonate) (PSDEM) and PEG-PSDEM-PEG and loaded with suberoylanilide hydroxamic acid (SAHA) employed as the RT sensitizer and indocyanine green (ICG) as the photothermal/photodynamic agent, demonstrated the capability of undergoing structural change and releasing therapeutic payloads in response to near-infrared irradiation and X-ray radiotherapy. With highly localized and controllable reactions within the tumor site, the reactive oxygen species (ROS)-triggered SAHA unloading and the hyperthermia-induced vascular permeability of oxygen led to a significant sensitization of the target tissue in RT, which, in turn, led to the promotion of therapeutic effect in conjunction with photodynamic/photothermal therapies (PDT/PTT). In vitro studies demonstrated the damage in intracellular DNA double strands and the inhibition of cell proliferation in 4T1 breast cancer cells treated with ROS-induced sensitized RT. A substantial reduction in cell viability was also observed owing to the effects of the combination of photo-mediated treatments with sensitized RT compared to the effects of RT administration alone. Complete eradication of the primary tumor and the inhibition of lung metastasis was observed in five of six orthotopic 4T1 breast cancer-bearing mice subjected to combined PDT/PTT in nanophototherapeutics with ROS-induced sensitized RT at a low dosage (6 Gy), leading to the prominent survival fraction of ca. 83% over 60 days.

Combo-targeted nanoassemblies as a chemotherapy delivery system against peritoneal carcinomatosis colorectal cancer.

Peritoneal carcinomatosis colorectal cancer (pcCRC) is one of the most challenging cases in clinical treatment due to its aggressive characteristics and diagnostic limitations, impeding the therapeutic efficacy of chemotherapy. In this study, a poly(lactic-co-glycolic acid) nanoparticle (NP)-based drug delivery system capable of encapsulating the chemodrug SN38 and enhancing drug accumulation in metastatic tumors was developed for the treatment of pcCRC. The SN38-loaded NPs with a diameter of ca. 160 nm were decorated with N-acetyl histidine-modified d-α-tocopheryl polyethylene glycol succinate (TPGS) and folate-TPGS on their surfaces for enhancing drug accumulation through surface charge conversion in a mildly acidic tumor microenvironment and further allowing the NPs to selectively target the folate receptor-overexpressed colon cancer cells. This hierarchically targeted drug delivery strategy improved not only the highly enhanced cellular uptake of drug-loaded NPs, but also the prominent anticancer effect against CT26 cancer cells in vitro. In vivo studies demonstrated the sound tumor inhibition of the SN38-loaded NPs in terms of large reductions in both tumor size and nodule number and prolongation of the survival time of pcCRC-bearing mice, indicating their high therapeutic potential for the practical treatment of pcCRC.

Dual stimuli-guided lipid-based delivery system of cancer combination therapy.

The combination therapy, as an emerging strategy for improved clinical efficacy of cancer therapy, may not achieve effective response owing to the lack of highly selective and efficient tumor targeting. Herein, a dual stimuli-guided chemo/magnetothermal combination therapy system based upon histamine dodecyl carbamate (HDC)-coated doxorubicin (DOX)/magnetite-loaded solid lipid nanoparticles (SLNs) was developed for enhanced anticancer effects. Taking advantage of the dual pHe-induced electrostatic and magnetic guidance, the in vitro cellular uptake of these functionalized SLNs by TRAMP-C1 cancer cells was highly enhanced, leading to remarkably increased anticancer ability. With the highly selective delivery of the therapeutics toward tumor via the dual stimuli-mediated guidance, the effective growth inhibition of tumors with the small initial size (ca 50 mm3) by only chemotherapy was observed whereas the combination therapy was essentially required to fully inhibit the growth of large tumors (200 mm3). The IHC staining of tumor tissue sections with the combination therapy against large tumors showed the appreciable increase of tumor cell apoptosis and reduction of tumor angiogenesis. The results suggest that the dual stimuli-guided combination therapy system developed herein be prominent in fully inhibiting tumor growth even with the solid tumors of large size at the onset of the treatment.

In vitro and in vivo study of the application of volvox spheres to co-culture vehicles in liver tissue engineering.

Volvox sphere is a biomimetic concept of a natural Volvox, wherein a large outer sphere contains smaller inner spheres, which can encapsulate cells and provide a double-layer three-dimensional environment for culturing cells. This study simultaneously encapsulated rat mesenchymal stem cells (MSCs) and AML12 hepatocytes in volvox spheres and extensively evaluated the effects of various culturing modes on cell functions and fates. The results showed that compared with a static flask culture, MSCs encapsulated in volvox spheres differentiated into hepatocyte-like cells with a 2-fold increase in albumin (ALB) expression and a 2.5-fold increase in cytokeratin 18 expression in a dynamic bioreactor. Moreover, the restorative effects of volvox spheres encapsulating cells on retrorsine-exposed CCl4-induced liver injuries in rats were evaluated. The data presented significant reductions in AST and ALT levels after the implantation of volvox spheres encapsulating both MSCs and AML12 hepatocytes in vivo. In contrast to the negative control group, histopathological analysis demonstrated liver repair and formation of the new liver tissue in groups implanted with volvox spheres containing cells. These results demonstrate that liver cells implanted with volvox spheres encapsulating both MSCs and AML12 hepatocytes promote liver repair and liver tissue regeneration in liver failure caused by necrotizing agents such as retrorsine and CCl4. Hence, volvox spheres encapsulating MSCs and liver cells can be a promising and clinically effective therapy for liver injury. STATEMENT OF SIGNIFICANCE: In this study, we used a volvox sphere, which is a unique design that mimics the natural Volvox, that consists of a large outer sphere that contains smaller inner spheres, which provide a three-dimensional environment to culture cells. The purpose of this study is to co-culture mesenchymal stem cells (MSCs) and AML12 liver cells in volvox spheres and evaluate two different culture methods, dynamic bioreactor and static culture flask,on the cultured cells. In addition, we aimed to evaluate the restorative effects of volvox spheres encapsulating MSCs and/or AML12 liver cells on rats with retrorsine-exposed CCl4-induced liver injuries. The results showed that MSCs encapsulated in volvox spheres differentiated into hepatocyte-like cells with a 2-fold increase in albumin expression and a 2.5-fold increase in cytokeratin 18 expression ina dynamic bioreactor. Moreover, the data presented significant reductions in AST and ALT levels after the implantation of volvox spheres encapsulating both MSCs and AML12 hepatocytes in vivo. In contrast to the negative control group, histopathological analysis demonstrated liver repair and formation of new liver tissue in groups implanted with volvox spheres containing cells. These results demonstrate that liver cells implanted with volvox spheres encapsulating both MSCs and AML12 hepatocytes promote liver repair and liver tissue regeneration in liver failure caused by necrotizing agents such as retrorsine and CCl4. Hence, volvox spheres encapsulating MSCs and liver cells can be a promising and clinically effective therapy for liver injury.

Effects of culturing media on hepatocytes differentiation using Volvox sphere as co-culturing vehicle.

Volvox sphere is a unique design to mimic natural volvox consists of a large outer-sphere that contains smaller inner-spheres, which provide three-dimensional (3D) environment to culture cells. The purpose of this study is to co-culture mesenchymal stem cells (MSCs) and AML12 liver cells in Volvox spheres and to evaluate the effects of two media, DMEM and DMEM/F12 on the cultured cells. The results of this study shows that the 3D Volvox sphere can successfully be applied for co-culture of MSCs and AML12 liver cells, and the MSCs are able to differentiate into hepatocyte-like cells expressing hepatocyte-specific markers including albumin (ALB), alpha feto-protein (AFP) and cytokeratin 18 (CK18) mRNA expressions and producing CK18 and ALB proteins. Interestingly, the MSCs expressed higher ALB, AFP and CK18 mRNA expression at the initial 7-day culture by using DMEM, whereas, the MSCs expressed more mRNA expressions from 7-day to 14-day by the usage of DMEM/F12. The result demonstrated that DMEM and DMEM/F12 media could affect MSCs behaviors during a 14-day culture.