Microcurrent Cloth-Assisted Transdermal Penetration and Follicular Ducts Escape of Curcumin-Loaded Micelles for Enhanced Wound Healing

Purpose

Larger nanoparticles of bioactive compounds deposit high concentrations in follicular ducts after skin penetration. In this study, we investigated the effects of microcurrent cloth on the skin penetration and translocation of large nanoparticle applied for wound repair applications.

Methods

A self-assembly of curcumin-loaded micelles (CMs) was prepared to improve the water solubility and transdermal efficiency of curcumin. Microcurrent cloth (M) was produced by Zn/Ag electrofabric printing to facilitate iontophoretic transdermal delivery. The transdermal performance of CMs combined with M was evaluated by a transdermal system and confocal microscopy. The CMs/iontophoretic combination effects on nitric oxide (NO) production and inflammatory cytokines were evaluated in Raw 264.7 cells. The wound-healing property of the combined treatment was assessed in a surgically created full-thickness circular wound mouse model.

Results

Energy-dispersive X-ray spectroscopy confirmed the presence of Zn/Ag on the microcurrent cloth. The average potential of M was measured to be +214.6 mV in PBS. Large particle CMs (CM-L) prepared using surfactant/cosurfactant present a particle size of 142.9 nm with a polydispersity index of 0.319. The solubility of curcumin in CM-L was 2143.67 μg/mL, indicating 250-fold higher than native curcumin (8.68 μg/mL). The combined treatment (CM-L+M) demonstrated a significant ability to inhibit NO production and increase IL-6 and IL-10 secretion. Surprisingly, microcurrent application significantly improved 20.01-fold transdermal performance of curcumin in CM-L with an obvious escape of CM-L from follicular ducts to surrounding observed by confocal microscopy. The CM-L+M group also exhibited a better wound-closure rate (77.94% on day 4) and the regenerated collagen intensity was approximately 2.66-fold higher than the control group, with a closure rate greater than 90% on day 8 in vivo.

Conclusion

Microcurrent cloth play as a promising iontophoretic transdermal drug delivery accelerator that enhances skin penetration and assists CMs to escape from follicular ducts for wound repair applications.

Radiotherapy enhances CXCR3highCD8+ T cell activation through inducing IFNγ-mediated CXCL10 and ICAM-1 expression in lung cancer cells

Radiotherapy (RT) not only damages tumors but also induces interferon (IFN) expression in tumors. IFNs mediate PD-L1 to exhaust CD8⁺ T cells, but which also directly impact tumor cells and potentially activate anti-tumor immune surveillance. Little is known about the contradictory mechanism of IFNs in regulating CD8⁺ T-mediated anti-tumor activity in lung cancer. This study found that RT induced IFNs and CXCL9/10 expression in the RT-treated lung cancer cells. Specifically, RT- and IFNγ-pretreated A549 significantly activated CD8⁺ T cells, resulting in significant inhibition of A549 colony formation. RNAseq and consequent qPCR results revealed that IFNγ induced PD-L1, CXCL10, and ICAM-1, whereas PD-L1 knockdown activated CD8⁺ T cells, but ICAM-1 knockdown diminished CD8⁺ T cell activation. We further demonstrated that CXCR3 and CXCL10 decreased in the CD8⁺ T cells and nonCD8⁺ PBMCs, respectively, in the patients with lung cancer that expressed lower reactivation as co-cultured with A549 cells. In addition, inhibitors targeting CXCR3 and LFA-1 in CD8⁺ T cells significantly diminished CD8⁺ T cell activation and splenocytes-mediated anti-LL/2shPdl1. In conclusion, we validated that RT suppressed lung cancer and overexpress PD-L1, CXCL10, and ICAM-1, which exhibited different roles in regulating CD8⁺ T cell activity. We propose that CXCR3^highCD8⁺ T cells stimulated by CXCL10 exhibit anti-tumor immunity, possibly by enhancing T cells-tumor cells adhesion through CXCL10/CXCR3-activated LFA-1-ICAM-1 interaction, but CXCR3^lowCD8⁺ T cells with low CXCL10 in patients with lung cancer were exhausted by PD-L1 dominantly. Therefore, RT potentially activates CD8⁺ T cells by inducing IFNs-mediated CXCL10 and ICAM-1 expression in tumors to enhance CD8⁺ T-tumor adhesion and recognition. This study clarified the possible mechanisms of RT and IFNs in regulating CD8⁺ T cell activation in lung cancer.

Develop companion radiopharmaceutical YKL40 antibodies as potential theranostic agents for epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is usually diagnosed at an advanced stage and has poor prognosis. Theranostic agents are the current trend in drug development, but are lacking in EOC. YKL40 is predominantly expressed and involved in tumorigenesis in EOC. In this study, we developed a companion theranostic agent targeting YKL40. We measured YKL40 expression levels in ascites using ELISA and correlated them with the clinical outcomes of patients with EOC. We developed radionuclide labeled In-111/Lu-177-DTPA-YKL40 neutralizing antibodies and investigated their radiochemical purity, SPECT/CT imaging, bio-distribution, and therapeutic responses in ovarian cancer xenograft mice. We demonstrated that YKL40 expression levels in ascites were significantly higher in EOC patients with serous histological type, high tumor grade, advanced stage, tumor recurrence, chemoresistance, and tumor-related death. The radiochemical purity of In-111/Lu-177-DTPA-YKL40 neutralizing antibodies reached more than 90% after 24 h of labeling. SPECT/CT imaging showed significant accumulation of In-111-DTPA-YKL40 and Lu-177-DTPA-YKL40 antibodies at the tumor site of ovarian cancer xenograft mice 24 h after administration. Lu-177-DTPA-YKL40 antibodies significantly inhibited tumor growth in ovarian cancer xenograft mice. Our study indicated that In-111/Lu-177-DTPA-YKL40 neutralizing antibodies could be potential companion theranostic agents for patients with EOC.

Sorafenib suppresses radioresistance and synergizes radiotherapy-mediated CD8+ T cell activation to eradicate hepatocellular carcinoma

Radiotherapy (RT) is applied to eradicate tumors in the clinic. However, hepatocellular carcinoma (HCC) exhibits resistance against RT. It is demonstrated that RT directly inhibits tumor growth but which induces type I interferons (IFNs) expression to phosphorylate STATs and increase STATs-downstream PD-L1 levels in the survival tumor cells. Since sorafenib is capable of suppressing STATs, we, therefore, hypothesize that sorafenib suppresses IFNs-mediated radioresistance and PD-L1 in the residual tumor cells and may synergistically enhance RT-mediated reactivation of CD8⁺ T immunological activity to eradicate HCC cells. We found that combined RT, sorafenib, and PBMCs significantly suppress the colony formation in the HCC cells, whereas CD8⁺ T cells expressed high granzyme B (GZMB) and perforin (PRF1) in co-cultured with RT-treated HCC cells. We demonstrated RT significantly inhibited HCC cell viability but induced IFNα and IL-6 expression in the RT-treated HCC cells, resulting in immune checkpoint PD-L1 and anti-apoptosis MCL1 and BCL2 overexpression in the non-RT HCC cells. We found that sorafenib decreased RT-PLC5 medium (RT-PLC5-m)-mediated cell growth by suppressing IFNα- and IL-6-mediated STAT1 and STAT3 phosphorylation. Sorafenib also reduced IFNα-mediated PD-L1 levels in HCC cells. Meanwhile, RT-PLC5-m reactivated CD8⁺ T cells and non-CD8⁺ PBMCs, resulting in high IFNγ and IL-2 levels in CD8⁺ T cells, and cytokines IFNα, IFNγ, IL-2, and IL-6 in non-CD8⁺ PBMCs. Particularly, CD8⁺ T cells expressed higher GZMB and PRF1 and non-CD8⁺ PBMCs expressed higher IFNα, IFNγ, IL-2, IL-6, CXCL9, and CXCL10 in co-cultured with RT-treated HCC cells compared to parental cells. Although we demonstrated that sorafenib slightly inhibited RT-mediated GZMB and PRF1 expression in CD8⁺ T cells, and cytokines levels in non-CD8⁺ PBMCs. Based on sorafenib significantly suppressed IFNα- and IL-6-mediated radioresistance and PD-L1 expression, we demonstrated that sorafenib synergized RT and immune surveillance for suppressing PLC5 cell viability in vitro. In conclusion, this study revealed that RT induced IFNα and IL-6 expression to phosphorylate STAT1 and STAT3 by autocrine and paracrine effect, leading to radioresistance and PD-L1 overexpression in HCC cells. Sorafenib not only suppressed IFNα- and IL-6-mediated PLC5 cell growth but also inhibited IFNα-mediated PD-L1 expression, synergistically enhancing RT-mediated CD8⁺ T cell reactivation against HCC cells.

Dual-Functional Polymeric Micelles Co-Loaded with Antineoplastic Drugs and Tyrosine Kinase Inhibitor for Combination Therapy in Colorectal Cancer

The aim of this research was to evaluate the receptor tyrosine kinase inhibitor Sunitinib combined with SN-38 in polymeric micelles for antitumor efficacy in colorectal cancer. First, SN-38 and Sunitinib co-loaded micelles were developed and characterized. We studied cell viability and cellular uptake in HCT-116 cells. Then, subcutaneous HCT-116 xenograft tumors were used for ex vivo biodistribution, antitumor efficacy, and histochemical analysis studies. Results of cellular uptake and ex vivo biodistribution of SN-38/Sunitinib micelles showed the highest accumulation in tumors compared with other normal organs. In the antitumor effect studies, mice bearing HCT-116 tumors were smallest at day 28 after injection of SN-38/Sunitinib micelles, compared with other experiment groups (p < 0.01). As demonstrated by the results of inhibition on multi-receptors by Sunitinib, we confirmed that SN-38/Sunitinib co-loaded micelles to be a treatment modality that could inhibit VEGF and PDGF receptors and enhance the antitumor effect of SN-38 (p < 0.05). In summary, we consider that this micelle is a potential formulation for the combination of SN-38 and Sunitinib in the treatment of colorectal cancer.

Irradiation Suppresses IFNγ-Mediated PD-L1 and MCL1 Expression in EGFR-Positive Lung Cancer to Augment CD8+ T Cells Cytotoxicity

Tumor cells express immune checkpoints to exhaust CD8⁺ T cells. Irradiation damages tumor cells and augments tumor immunotherapy in clinical applications. However, the radiotherapy-mediated molecular mechanism affecting CD8⁺ T cell activity remains elusive. We aimed to uncover the mechanism of radiotherapy augmenting cytotoxic CD8⁺ T cells in non-small-cell lung cancer (NSCLC). EGFR-positive NSCLC cell lines were co-cultured with CD8⁺ T cells from healthy volunteers. Tumor cell viability and apoptosis were consequently measured. IFNγ was identified secreted by CD8⁺ T cells and PBMCs. Therefore, RNAseq was used to screen the IFNγ-mediated gene expression in A549 cells. The irradiation effect to IFNγ-mediated gene expression was investigated using qPCR and western blots. We found that the co-culture of tumor cells stimulated the increase of granzyme B and IFNγ in CD8⁺ T, but A549 exhibited resistance against CD8⁺ T cytotoxicity compared to HCC827. Irradiation inhibited A549 proliferation and enhanced apoptosis, augmenting PBMCs-mediated cytotoxicity against A549. We found that IFNγ simultaneously increased phosphorylation on STAT1 and STAT3 in EGFR-positive lung cancer, resulting in overexpression of PD-L1 (p < 0.05). In RNAseq analysis, MCL1 was identified and increased by the IFNγ-STAT3 axis (p < 0.05). We demonstrated that irradiation specifically inhibited phosphorylation on STAT1 and STAT3 in IFNγ-treated A549, resulting in reductions of PD-L1 and MCL1 (both p < 0.05). Moreover, knockdowns of STAT3 and MCL1 increased the PBMCs-mediated anti-A549 effect. This study demonstrated that A549 expressed MCL1 to resist CD8⁺ T cell-mediated tumor apoptosis. In addition, we found that irradiation suppressed IFNγ-mediated STAT3 phosphorylation and PD-L1 and MCL1 expression, revealing a potential mechanism of radiotherapy augmenting immune surveillance.

A novel 111indium-labeled dual carbonic anhydrase 9-targeted probe as a potential SPECT imaging radiotracer for detection of hypoxic colorectal cancer cells

Tumor hypoxia is a common feature in colorectal cancer (CRC), and is associated with resistance to radiotherapy and chemotherapy. Thus, a specifically targeted probe for the detection of hypoxic CRC cells is urgently needed. Carbonic anhydrase 9 (CA9) is considered to be a specific marker for hypoxic CRC diagnosis. Here, a nuclear imaging Indium-111 (¹¹¹In)-labeled dual CA9-targeted probe was synthesized and evaluated for CA9 detection in in vitro, in vivo, and in human samples. The CA9-targeted peptide (CA9tp) and CA9 inhibitor acetazolamide (AAZ) were combined to form a dual CA9-targeted probe (AAZ-CA9tp) using an automatic microwave peptide synthesizer, which then was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for radioisotope (¹¹¹In) labeling (¹¹¹In-DOTA-AAZ-CA9tp). The assays for cell binding, stability, and toxicity were conducted in hypoxic CRC HCT15 cells. The analyses for imaging and biodistribution were performed in an HCT15 xenograft mouse model. The binding and distribution of ¹¹¹In-DOTA-AAZ-CA9tp were detected in human CRC samples using microautoradiography. AAZ-CA9tp possessed good CA9-targeting ability in hypoxic HCT15 cells. The dual CA9-targeted radiotracer showed high serum stability, high surface binding, and high affinity in vitro. After exposure of ¹¹¹In-DOTA-AAZ-CA9tp to the HCT15-bearing xenograft mice, the levels of ¹¹¹In-DOTA-AAZ-CA9tp were markedly and specifically increased in the hypoxic tumor tissues compared to control mice. ¹¹¹In-DOTA-AAZ-CA9tp also targeted the areas of CA9 overexpression in human colorectal tumor tissue sections. The results of this study suggest that the novel ¹¹¹In-DOTA-AAZ-CA9tp nuclear imaging agent may be a useful tool for the detection of hypoxic CRC cells in clinical practice.

Hyaluronan-Loaded Liposomal Dexamethasone-Diclofenac Nanoparticles for Local Osteoarthritis Treatment

Osteoarthritis (OA) remains one of the common degenerative joint diseases and a major cause of pain and disability in older adult individuals. Oral administration of non-steroidal anti-inflammatory drugs (NSAIDs) (such as diclofenac, DIC) or intra-articular injected gluco-corticosteroids (such as dexamethasone, DEX) were the conventional treatment strategies for OA to reduce joint pain. Current limitations for both drugs including severe adverse effects with risks of toxicity were noted. The aim of the present study was to generate a novel OA treatment formulation hyaluronic acid (HA)-Liposomal (Lipo)-DIC/DEX to combat joint pain. The formulation was prepared by constructing DIC with DEX-loaded nanostructured lipid carriers Lipo-DIC/DEX mixed with hyaluronic acid (HA) for prolonged OA application. The prepared Lipo-DIC/DEX nanoparticles revealed the size as 103.6 ± 0.3 nm on average, zeta potential as −22.3 ± 4.6 mV, the entrapment efficiency of 90.5 ± 5.6%, and the DIC and DEX content was 22.5 ± 4.1 and 2.5 ± 0.6%, respectively. Evidence indicated that HA-Lipo-DIC/DEX could reach the effective working concentration in 4 h and sustained the drug-releasing time for at least 168 h. No significant toxicities but increased cell numbers were observed when HA-Lipo-DIC/DEX co-cultured with articular chondrocytes cells. Using live-animal In vivo imaging system (IVIS), intra-articular injection of each HA-Lipo-DIC/DEX sufficed to reduce knee joint inflammation in OA mice over a time span of four weeks. Single-dose injection could reduce the inflammation volume down to 77.5 ± 5.1% from initial over that time span. Our results provided the novel drug-releasing formulation with safety and efficiency which could be a promising system for osteoarthritis pain control.

Nicotine exhausts CD8+ T cells against tumor cells through increasing miR-629-5p to repress IL2RB-mediated granzyme B expression

The mechanism exhausting CD8⁺ T cells is not completely clear against tumors. Literature has demonstrated that cigarette smoking disables the immunological activity, so we propose nicotine is able to exhaust CD8⁺ T cells. The CD8⁺ T cells from healthy volunteers with and without cigarette smoking and the capacity of CD8⁺ T cells against tumor cells were investigated. RNAseq was used to investigate the gene profiling expression in CD8⁺ T cells. Meanwhile, small RNAseq was also used to search novel microRNAs involved in the exhaustion of CD8⁺ T cells. The effect of nicotine exhausting CD8⁺ T cells was investigated in vitro and in the humanized tumor xenografts in vivo. We found that CD8⁺ T cells were able to reduce cell viability in lung cancer HCC827 and A549 cells, that secreted granzyme B, but CD8⁺ T cells from the healthy cigarette smokers lost anti-HCC827 effect. Moreover, nicotine suppressed the anti-HCC827 effect of CD8⁺ T cells. RNAseq revealed lower levels of IL2RB and GZMB in the exhausted CD8⁺ T cells. We identified that miR-629-5p was increased by nicotine, that targeted IL2RB. Transfection of miR-629-5p mimic reduced IL2RB and GZMB levels. We further validated that nicotine reduced granzyme B levels using a nuclear imaging technique, and demonstrated that nicotine exhausted peripheral blood mononuclear cells against HCC827 growth in the humanized tumor xenografts. This study demonstrated that nicotine exhausted CD8⁺ T cells against HCC827 cells through increasing miR-629-5p to suppress IL2RB.

Liposomal dexamethasone-moxifloxacin nanoparticle combinations with collagen/gelatin/alginate hydrogel for corneal infection treatment and wound healing

Infectious keratitis is still one of the major causes of visual impairment and blindness, often affecting developing countries. Eye-drop therapy to reduce disease progression is the first line of treatment for infectious keratitis. The current limitations in controlling ophthalmic infections include rapid precorneal drug loss and the inability to provide long-term extraocular drug delivery. The aim of the present study was to develop a novel ophthalmic formulation to treat corneal infection. The formulation was prepared by constructing moxifloxacin (MFX) and dexamethasone (DEX)-loaded nanostructured lipid carriers (Lipo-MFX/DEX) mixed with a collagen/gelatin/alginate (CGA) biodegradable material (CGA-Lipo-MFX/DEX) for prolonged ocular application. The characteristics of the prepared Lipo-MFX/DEX nanoparticles were as follows: average size, 132.1 ± 73.58 nm; zeta potential, -6.27 ± 4.95 mV; entrapment efficiency, 91.5 ± 3.5%; drug content, 18.1 ± 1.7%. Our results indicated that CGA-Lipo-MFX/DEX could release an effective working concentration in 60 min and sustain the drug release for at least 12 h. CGA-Lipo-MFX/DEX did not produce significant toxicities, but it increased cell numbers when co-cultured with ocular epithelial cells. An animal study also confirmed that CGA-Lipo-MFX/DEX could inhibit pathogen microorganism growth and improve corneal wound healing. Our results suggest that CGA-Lipo-MFX/DEX could be a useful anti-inflammatory formulation for ophthalmological disease treatment.

Epidermal growth factor induces STAT1 expression to exacerbate the IFNr-mediated PD-L1 axis in epidermal growth factor receptor-positive cancers

The epidermal growth factor (EGF) receptor (EGFR) overexpressed in many cancers, including lung and head and neck cancers, and is involved in cancer cell progression and survival. PD-L1, increases in tumor cells to evade and inhibit CD8+ T cells, is a clinical immunotherapeutic target. This study investigated the molecular mechanism of EGF on regulating PD-L1 in EGFR-positive cancers and determined potential agents to reduce PD-L1 expression. RNA sequencing (RNAseq) and bioinformatics analysis were performed to determine potential driver genes that regulate PD-L1 in tumor cells-derived tumorspheres which mimicking cancer stem cells. Then, the specific inhibitors targeting EGFR were applied to reduce the expression of PD-L1 in vitro and in vivo. We validated that EGF could induce PD-L1 expression in the selected EGFR-positive cancers. RNAseq results revealed that STAT1 increased as a driver gene in KOSC-3-derived tumorspheres; these data were analyzed using PANTHER followed by NetworkAnalyst. The blockade of EGFR by afatinib resulted in decreased STAT1 and IRF-1 levels, both are transcriptional factors of PD-L1, and disabled the IFNr-STAT1-mediated PD-L1 axis in vitro and in vivo. Moreover, STAT1 knockdown significantly reduced EGF-mediated PD-L1 expression, and ruxolitinib, a JAK1/JAK2 inhibitor, significantly inhibited STAT1 phosphorylation to reduce the IFNr-mediated PD-L1 axis. These results indicate that EGF exacerbates PD-L1 by increasing the protein levels of STAT1 to enforce the IFNr-JAK1/2-mediated signaling axis in selected EGFR-positive cancers. The inhibition of EGFR by afatinib significantly reduced PD-L1 and may be a potential strategy for enhancing immunotherapeutic efficacy.

Abstract 3060: EGFR-mediated interleukin enhancer-binding factor 3 contributes to formation and survival of cancer stem-like tumorspheres through regulating HER3/ERBB3 expression as a therapeutic target against EGFR-positive non-small cell lung cancer

Objectives: YM155, an inhibitor of interleukin enhancer-binding factor 3 (ILF3), significantly suppresses cancer stemness property, implying that ILF3 contributes to cell survival of cancer stem cells. However, the molecular function of ILF3 inhibiting cancer stemness remain unclear. This study aimed to uncover the potential function of ILF3 involving in cell survival of epidermal growth factor receptor (EGFR)-positive lung stem-like cancer, and investigate the potential role to improve the efficacy of anti-EGFR therapeutics.

Materials and Methods: The regulated association of EGFR and ILF3 was investigated at first. ILF3 was knockdowned and RNAseq was utilized to search for the putative genes regulated by ILF3. Meanwhile, HCC827- and A549-derived cancer stem-like cells were used to investigate the role of ILF3 in the formation of cancer stem-like tumorspheres.

Results: We found that EGFR induced ILF3 expression, and YM155 reduced EGFR expression. The knockdown of ILF3 reduced not only EGFR expression in mRNA and protein levels, but also cell proliferation in vitro and in vivo, demonstrating that ILF3 was an oncoprotein contributing to cancer cell survival. Moreover, the knockdown and inhibition of ILF3 by shRNA and YM155, respectively, reduced the formation and survival of HCC827- and A549-derived tumorspheres through inhibiting HER3/ERBB3 expression, and synergized the therapeutic efficacy of afatinib, a tyrosine kinase inhibitor, against EGFR-positive A549 lung cells.

Conclusion: This study demonstrated that ILF3 played an oncogenic role maintaining the EGFR-mediated cellular pathway as a therapeutic target to improve the therapeutic efficacy of afatinib. Therefore, we suggested that YM155, an ILF3 inhibitor, was potential for utilization in cancer therapy against the EGFR-positive cancers.

Citation Format: Chun-Chia Cheng, Kuei-Fang Chou, Cheng-Wen Wu, Nai-Wen Su, Cheng-Liang Peng, Ying-Wen Su, Jungshan Chang, Ai-Sheng Ho, Huan-Chau Lin, Caleb Gon-Shen Chen, Yu-Cheng Chang, Ken-Hong Lim, Yi-Fang Chang. EGFR-mediated interleukin enhancer-binding factor 3 contributes to formation and survival of cancer stem-like tumorspheres through regulating HER3/ERBB3 expression as a therapeutic target against EGFR-positive non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3060.

Anti-angiogenic treatment (Bevacizumab) improves the responsiveness of photodynamic therapy in colorectal cancer

Photodynamic therapy (PDT) is a treatment utilizing the combined action of photosensitizers and light for the treatment of various cancers. The mechanisms for tumor destruction after PDT include direct tumor cell kill by singlet oxygen species (OS), indirect cell kill via vascular damage, and an elicited immune response. However, it has been reported that many cellular activators, including vascular endothelial growth factor (VEGF), are produced by tumor cells after PDT. In this study, we demonstrate that meta-tetra(hydroxyphenyl) chlorin (mTHPC)-based photodynamic therapy combined with bevacizumab (Avastin™), an anti-VEGF neutralizing monoclonal antibody that blocks the binding of VEGF to its receptor, can enhance the effectiveness of each treatment modality. We evaluated the efficacy of bevacizumab-based anti-angiogenesis in combination with PDT as well as the resulting VEGF levels and microvessel density (MVD) in a mouse model of human colon cancer. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) were performed to assess VEGF concentrations and microvessel density in the various treatment groups, and confocal imaging and high performance liquid chromatography (HPLC) analyses were used to measure the distribution and concentration of mTHPC in tumors. Our results demonstrate that combination of PDT followed by bevacizumab significantly elicits a greater tumor response whereas bevacizumab treatment prior to PDT led to a reduced tumor response. Immunostaining and ELISA analyses revealed a lower expression of VEGF in tumors treated with combination therapy of PDT followed by bevacizumab. However, bevacizumab treatment decreased the accumulation of mTHPC in tumors 24 h after administration, which complemented the results of decreased anti-tumor efficacy of bevacizumab followed by PDT.

pH-Responsive Nanophotosensitizer for an Enhanced Photodynamic Therapy of Colorectal Cancer Overexpressing EGFR

Photodynamic therapy (PDT) has been shown to kill cancer cells and improve survival and quality of life in cancer patients, and numerous new approaches have been considered for maximizing the efficacy of PDT. In this study, a new multifunctional nanophotosensitizer Ce6/GE11-^(pH)micelle was developed to target epidermal growth factor receptor (EGFR) overexpressing colorectal cancer (CRC) cells. This nanophotosensitizer was synthesized using a micelle comprising pH-responsive copolymers (PEGMA-PDPA), biodegradable copolymers (mPEG-PCL), and maleimide-modified biodegradable copolymers (Mal-PEG-PCL) to entrap the potential hydrophobic photosensitizer chlorin e6 (Ce6) and to present EGFR-targeting peptides (GE11) on its surface. In the presence of Ce6/GE11-^(pH)micelles, Ce6 uptake by EGFR-overexpressing CRC cells significantly increased due to GE11 specificity. Moreover, Ce6 was released from Ce6/GE11-^(pH)micelles in tumor environments, leading to improved elimination of cancer cells in PDT. These results indicate enhanced efficacy of PDT using Ce6/GE11-^(pH)micelle, which is a powerful nanophotosensitizer with high potential for application to future PDT for CRC.

Panitumumab-Conjugated and Platinum-Cored pH-Sensitive Apoferritin Nanocages for Colorectal Cancer-Targeted Therapy

Apoferritin (AF) is a natural nontoxic iron carrier and has a natural hollow structure that can be used to deliver small molecules. The surface of AF has many amine functional groups that can be modified to create targeted ligands. We loaded oxaliplatin onto AF, which was then used as a template to conjugate with panitumumab via a polyethylene glycol linker. The oxaliplatin-loaded AF conjugated with panitumumab (AFPO) was designed to specifically target cell lines expressing epidermal growth factor receptor (EGFR). AFPO efficiently released oxaliplatin and suppressed tumor cell growth. Furthermore, the novel AFPO nanocages showed significant inhibition and greater accumulation in tumor models with high EGFR expression in vivo. Our study revealed that combining panitumumab and oxaliplatin into one formulation (AFPO nanocage) could be a promising shortcut in clinical applications.

EGFR-mediated interleukin enhancer-binding factor 3 contributes to formation and survival of cancer stem-like tumorspheres as a therapeutic target against EGFR-positive non-small cell lung cancer

OBJECTIVES

YM155, an inhibitor of interleukin enhancer-binding factor 3 (ILF3), significantly suppresses cancer stemness property, implying that ILF3 contributes to cell survival of cancer stem cells. However, the molecular function of ILF3 inhibiting cancer stemness remains unclear. This study aimed to uncover the potential function of ILF3 involving in cell survival of epidermal growth factor receptor (EGFR)-positive lung stem-like cancer, and to investigate the potential role to improve the efficacy of anti-EGFR therapeutics.

MATERIALS AND METHODS

The association of EGFR and ILF3 in expression and regulations was first investigated in this study. Lung cancer A549 cells with deprivation of ILF3 were created by the gene-knockdown method and then RNAseq was applied to identify the putative genes regulated by ILF3. Meanwhile, HCC827- and A549-derived cancer stem-like cells were used to investigate the role of ILF3 in the formation of cancer stem-like tumorspheres.

RESULTS

We found that EGFR induced ILF3 expression, and YM155 reduced EGFR expression. The knockdown of ILF3 reduced not only EGFR expression in mRNA and protein levels, but also cell proliferation in vitro and in vivo, demonstrating that ILF3 may play an important role in contributing to cancer cell survival. Moreover, the knockdown and inhibition of ILF3 by shRNA and YM155, respectively, reduced the formation and survival of HCC827- and A549-derived tumorspheres through inhibiting ErbB3 (HER3) expression, and synergized the therapeutic efficacy of afatinib, a tyrosine kinase inhibitor, against EGFR-positive A549 lung cells.

CONCLUSION

This study demonstrated that ILF3 plays an oncogenic like role in maintaining the EGFR-mediated cellular pathway, and can be a therapeutic target to improve the therapeutic efficacy of afatinib. Our results suggested that YM155, an ILF3 inhibitor, has the potential for utilization in cancer therapy against EGFR-positive lung cancers.

Photothermal, Targeting, Theranostic Near-Infrared Nanoagent with SN38 against Colorectal Cancer for Chemothermal Therapy

Cancer research regarding near-infrared (NIR) agents for chemothermal therapy (CTT) has shown that agents with specific functions are able to inhibit tumor growth. The aim of current study was to optimize CTT efficacy for treatment of colorectal cancer (CRC) by exploring strategies which can localize high temperature within tumors and maximize chemotherapeutic drug uptake. We designed a new and simple multifunctional NIR nanoagent composed of the NIR cyanine dye, polyethylene glycol, and a cyclic arginine-glycine-aspartic acid peptide and loaded with the anti-CRC chemotherapeutic agent, 7-ethyl-10-hydroxy-camptothecin (SN38). Each component of this nanoagent exhibited its specific functions that help boost CTT efficacy. The results showed that this nanoagent greatly strengthens the theranostic effect of SN38 and CTT against CRC due to its NIR imaging ability, photothermal, enhanced permeability and retention (EPR) effect, reticuloendothelial system avoidance, and angiogenic blood vessel-targeting properties. This NIR nanoagent will help facilitate development of new strategies for treating CRC.

Panitumumab-Conjugated Pt-Drug Nanomedicine for Enhanced Efficacy of Combination Targeted Chemotherapy against Colorectal Cancer

Targeted combination chemotherapy (TCT) has recently been used to increase the induction of tumor cell death. In particular, the combination of Panitumumab and the platinum (Pt)-derived chemotherapeutic drug Oxaliplatin is clinically effective against KRAS and BRAF wild-type colorectal cancer (CRC) cells that overexpress epidermal growth factor receptors, and significantly greater efficacy is observed than with either drug alone. However, low accumulation of Pt drug in tumor sites prevents achievement of ideal efficacy. To develop an alternative drug therapy that achieves the ideal efficacy of TCT, the novel nanomedicine NANO_Pt-Pan using self-assembled dichloro(1,2-diaminocyclohexane)Pt(II)-modified Panitumumab is generated. Treatments with NANO_Pt-Pan lead to significant accumulation of Pt drug and Panitumumab in tumors, reflecting enhanced permeability and retention effect, active targeting, and sustained circulation of the Pt drug in the blood. In addition, NANO_Pt-Pan has excellent in vivo anti-CRC efficacy. These data indicate that NANO_Pt-Pan has high potential as a candidate nanomedicine for CRC.

Pigment patterns and photoprotection of anthocyanins in the young leaves of four dominant subtropical forest tree species in two successional stages under contrasting light conditions

Light-driven subtropical forest succession is a dynamic process in which mesophytic climax communities replace heliophytic ones. Juvenile leaves (particularly mesophytic ones) are sensitive to high irradiances. To determine the photoprotection strategy that juvenile leaves use during subtropical forest succession, anthocyanin accumulation patterns were investigated in the young leaves of two mid-successional dominant trees (i.e., Schima superba and Castanopsis fissa) and two late-successional dominant trees (i.e., Cryptocarya concinna and Acmena acuminatissima) grown in 100% (FL) and 25% (LL) of full sunlight. All four tree species produced anthocyanins in their juvenile leaves when <50% of chlorophylls and carotenoids had developed. Higher anthocyanin concentrations accumulated in the young leaves grown in FL than in those grown in LL and in late-successional than in mid-successional trees. The juvenile leaves of late-successional trees were subjected to higher light-induced photoinhibition than those of mid-successional trees, despite of the fact that the leaves of late-successional trees showed greater non-photochemical quenching than those of mid-successional trees. Under LL conditions, photosystem II excitation pressure (1 - qP) was significantly higher in the juvenile leaves of late-successional trees than those of mid-successional trees. Under either FL or LL conditions, anthocyanin concentrations in juvenile leaves were negatively related to the light compensation point in mature leaves across species. However, anthocyanin concentrations were positively related to the antioxidant capacity of juvenile leaves. These results indicate that anthocyanin accumulation in the juvenile leaves of subtropical dominant trees during forest community succession is a flexible photoprotective response to ambient irradiances according to leaf sensitivity to light.

A novel temperature-responsive micelle for enhancing combination therapy

A novel thermosensitive polymer p(N-isopropylacrylamide-co-poly[ethylene glycol] methyl ether acrylate)-block-poly(epsilon-caprolactone), p(NIPAAM-co-PEGMEA)-b-PCL, was synthesized and developed as nanomicelles. The hydrophobic heat shock protein 90 inhibitor 17-allylamino-17-demethoxygeldanamycin and the photosensitizer cyanine dye infrared-780 were loaded into the core of the micelles to achieve both chemotherapy and photothermal therapy simultaneously at the tumor site. The release of the drug could be controlled by varying the temperature due to the thermosensitive nature of the micelles. The micelles were less than 200 nm in size, and the drug encapsulation efficiency was >50%. The critical micelle concentrations were small enough to allow micelle stability upon dilution. Data from cell viability and animal experiments indicate that this combination treatment using photothermal therapy with chemotherapy had synergistic effects while decreasing side effects.

Targeting Colorectal Cancer Stem-Like Cells with Anti-CD133 Antibody-Conjugated SN-38 Nanoparticles

Cancer stem-like cells play a key role in tumor development, and these cells are relevant to the failure of conventional chemotherapy. To achieve favorable therapy for colorectal cancer, PEG-PCL-based nanoparticles, which possess good biological compatibility, were fabricated as nanocarriers for the topoisomerase inhibitor, SN-38. For cancer stem cell therapy, CD133 (prominin-1) is a theoretical cancer stem-like cell (CSLC) marker for colorectal cancer and is a proposed therapeutic target. Cells with CD133 overexpression have demonstrated enhanced tumor-initiating ability and tumor relapse probability. To resolve the problem of chemotherapy failure, SN-38-loaded nanoparticles were conjugated with anti-CD133 antibody to target CD133-positive (CD133(+)) cells. In this study, anti-CD133 antibody-conjugated SN-38-loaded nanoparticles (CD133Ab-NPs-SN-38) efficiently bound to HCT116 cells, which overexpress CD133 glycoprotein. The cytotoxic effect of CD133Ab-NPs-SN-38 was greater than that of nontargeted nanoparticles (NPs-SN-38) in HCT116 cells. Furthermore, CD133Ab-NPs-SN-38 could target CD133(+) cells and inhibit colony formation compared with NPs-SN-38. In vivo studies in an HCT116 xenograft model revealed that CD133Ab-NPs-SN-38 suppressed tumor growth and retarded recurrence. A reduction in CD133 expression in HCT116 cells treated with CD133Ab-NPs-SN-38 was also observed in immunohistochemistry results. Therefore, this CD133-targeting nanoparticle delivery system could eliminate CD133-positive cells and is a potential cancer stem cell targeted therapy.

A theranostic micelleplex co-delivering SN-38 and VEGF siRNA for colorectal cancer therapy

The development of an efficient colorectal cancer therapy is currently a public health priority. In the present work, we proposed a multifunctional theranostic micellar drug delivery system utilizing cationic PDMA-block-poly(ε-caprolactone) (PDMA-b-PCL) micelles as nanocarriers of SN-38 (7-ethyl-10-hydroxycamptothecin), ultra-small superparamagnetic iron oxide nanoparticles (USPIO), and small interfering RNA (siRNA) that targets human vascular endothelial growth factor (VEGF). The VEGF siRNA was conjugated to polyethylene glycol (PEG) (siRNA-PEG) before complexation with the micelles in order to improve the siRNA's stability and to prolong its retention time in the blood circulation. To further improve the in vivo biosafety, we prepared mixed micelles using mPEG-PCL together with PDMA-b-PCL copolymer. The SN-38/USPIO-loaded siRNA-PEG mixed micelleplexes passively targeted to tumor regions and synergistically facilitated VEGF silencing and chemotherapy, thus efficiently suppressing tumor growth via a multi-dose therapy regimen. Additionally, the SN-38/USPIO-loaded siRNA-PEG mixed micelleplexes acted as a negative magnetic resonance imaging (MRI) contrast agent in T2-weighted imaging, resulting in a powerful tool for the diagnosis and for tracking of the therapeutic outcomes. In summary, we established a theranostic micellar drug and gene delivery system that not only synergistically combined gene silencing and chemotherapy but also served as a negative MRI contrast agent, which reveal its potential as a novel colorectal cancer therapy.

Combining the single-walled carbon nanotubes with low voltage electrical stimulation to improve accumulation of nanomedicines in tumor for effective cancer therapy

Effective delivery of biomolecules or functional nanoparticles into target sites has always been the primary objective for cancer therapy. We demonstrated that by combining single-walled carbon nanotubes (SWNTs) with low-voltage (LV) electrical stimulation, biomolecule delivery can be effectively enhanced through reversible electroporation (EP). Clear pore formation in the cell membrane is observed due to LV (50V) pulse electrical stimulation amplified by SWNTs. The cell morphology remains intact and high cell viability is retained. This modality of SWNT + LV pulses can effectively transfer both small molecules and macromolecules into cells through reversible EP. The results of animal studies also suggest that treatment with LV pulses alone cannot increase vascular permeability in tumors unless after the injection of SWNTs. The nanoparticles can cross the permeable vasculature, which enhances their accumulation in the tumor tissue. Therefore, in cancer treatment, both SWNT + LV pulse treatment followed by the injection of LIPO-DOX® and SWNT/DOX + LV pulse treatment can increase tumor inhibition and delay tumor growth. This novel treatment modality applied in a human cancer xenograft model can provide a safe and effective therapy using various nanomedicines in cancer treatment.

Development of a controlled-release drug delivery system by encapsulating oxaliplatin into SPIO/MWNT nanoparticles for effective colon cancer therapy and magnetic resonance imaging

The development of a controlled-release drug delivery system has been an important objective for cancer therapy.

Therapeutic and scintigraphic applications of polymeric micelles: combination of chemotherapy and radiotherapy in hepatocellular carcinoma

This study evaluated a multifunctional micelle simultaneously loaded with doxorubicin (Dox) and labeled with radionuclide rhenium-188 ((188)Re) as a combined radiotherapy and chemotherapy treatment for hepatocellular carcinoma. We investigated the single photon emission computed tomography, biodistribution, antitumor efficacy, and pathology of (188)Re-Dox micelles in a murine orthotopic luciferase-transfected BNL tumor cells hepatocellular carcinoma model. The single photon emission computed tomography and computed tomography images showed high radioactivity in the liver and tumor, which was in agreement with the biodistribution measured by γ-counting. In vivo bioluminescence images showed the smallest size tumor (P<0.05) in mice treated with the combined micelles throughout the experimental period. In addition, the combined (188)Re-Dox micelles group had significantly longer survival compared with the control, (188)ReO4 alone (P<0.005), and Dox micelles alone (P<0.01) groups. Pathohistological analysis revealed that tumors treated with (188)Re-Dox micelles had more necrotic features and decreased cell proliferation. Therefore, (188)Re-Dox micelles may enable combined radiotherapy and chemotherapy to maximize the effectiveness of treatment for hepatocellular carcinoma.

ESR1 gene polymorphisms PvuII (rs2234693T>C) and XbaI (rs9340799A>G) may not be directly correlated with cardiovascular disease risk

The aim of this meta-analysis was to evaluate the correlations between the estrogen receptor 1 (ESR1) gene polymorphisms PvuII (rs2234693T>C) and XbaI (rs9340799A>G) and the risk of cardiovascular disease (CVD). Case-control studies were screened and selected from a larger group of studies that were retrieved through a comprehensive search of scientific literature databases, which was complemented by manual searches. Data from studies selected were analyzed using the Comprehensive Meta-analysis 2.0 software. A total of 240 studies were initially retrieved and 10 studies were eventually included in the meta-analysis. These 10 case-control studies involved 7029 CVD patients (5001 myocardial infarction patients, 1223 coronary artery disease patients, 805 acute coronary syndromes patients) and 6901 healthy controls. We found no significant association between the PvuII (rs2234693T>C) and XbaI (rs9340799A>G) polymorphisms and CVD risk. We detected no significant associations under all genetic inheritance models tested, including the allele, dominant, homozygous, heterozygous, and recessive models, or for comparisons between the case group and control group (all P > 0.05). Our meta-analysis results strongly suggest that the ESR1 gene polymorphisms PvuII (rs2234693T>C) and XbaI (rs9340799A>G) are not associated with CVD risk.

Traceable Self-Assembly of Laser-Triggered Cyanine-Based Micelle for Synergistic Therapeutic Effect

To track nanocarriers, many researches adopt nanocarriers labeled with radiotracers or encapsulating near-infrared fluorescence (NIRF) dye. In this study, novel amphiphilic copolymers, methoxy poly(ethylene glycol) (mPEG)-cyanine-poly(ε-caprolactone) (PCL) (mPEG-Cy-PCL) are synthesized. mPEG-Cy-PCL are capable of performing NIRF imaging, photothermal therapy (PTT) on cancer cells and self-assembly nanocarriers. Cy-based micelles can encapsulate doxorubicin (Doxo@Cy-micelle) and achieve NIRF image-guided drug delivery. Doxo@Cy-micelles are nanosized micelles enhancing the accumulation of Doxo in tumor sites and decreasing side effects. Doxo@Cy-micelles exhibit an excellent PTT and synergistic chemotherapy of cancer via laser-triggered release of Doxo from micelles, eventually resulting in decreased cancer recurrence rates. The results show that Cy-based micelles are excellent nanocarriers for NIRF imaging and synergistic photothermal-chemotherapy of cancer.

Enhanced efficacy of chemotherapeutic drugs against colorectal cancer using ligand-decorated self-breakable agents

Targeting self-breakable micelles could facilitate Caco2 cancer cells in acidic tumor microenvironment to take up SN38 which the micelle loaded with and trigger drug release in cancer cells, resulting in enhanced drug efficacy.

Preparation and therapeutic evaluation of (188)Re-thermogelling emulsion in rat model of hepatocellular carcinoma

Radiolabeled Lipiodol^® (Guerbet, Villepinte, France) is routinely used in hepatoma therapy. The temperature-sensitive hydrogel polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol triblock copolymer is used as an embolic agent and sustained drug release system. This study attempted to combine the polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol hydrogel and radio-labeled Lipiodol to form a new radio-thermogelling emulsion, rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol/hydrogel (¹⁸⁸Re-ELH). The therapeutic potential of ¹⁸⁸Re-ELH was evaluated in a rodent hepatoma model. Rhenium-188 chelated with N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride was extracted with Lipiodol to obtain rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol (¹⁸⁸Re-EL), which was blended with the hydrogel in equal volumes to develop ¹⁸⁸Re-ELH. The ¹⁸⁸Re-ELH phase stability was evaluated at different temperatures. Biodistribution patterns and micro-single-photon emission computed tomography/computed tomography images in Sprague Dawley rats implanted with the rat hepatoma cell line N1-S1 were observed after in situ tumoral injection of ~3.7 MBq ¹⁸⁸Re-ELH. The therapeutic potential of ¹⁸⁸Re-EL (48.58±3.86 MBq/0.1 mL, n=12) was evaluated in a 2-month survival study using the same animal model. The therapeutic effects of ¹⁸⁸Re-ELH (25.52±4.64 MBq/0.1 mL, n=12) were evaluated and compared with those of ¹⁸⁸Re-EL. The responses were assessed by changes in tumor size and survival rates. The ¹⁸⁸Re-ELH emulsion was stable in the gel form at 25°C–35°C for >52 hours. Biodistribution data and micro-single-photon emission computed tomography/computed tomography images of the ¹⁸⁸Re-ELH group indicated that most activity was selectively observed in hepatomas. Long-term ¹⁸⁸Re-ELH studies have demonstrated protracted reductions in tumor volumes and positive effects on the survival rates (75%) of N1-S1 hepatoma-bearing rats. Conversely, the 2-month survival rate was 13% in the control sham group. Therapeutic responses differed significantly between the two groups (P<0.005). Thus, the hydrogel enhanced the injection stability of ¹⁸⁸Re-EL in an animal hepatoma model. Given the synergistic results, direct ¹⁸⁸Re-ELH intratumoral injection is a potential therapeutic alternative for hepatoma treatment.

Novel targeted nuclear imaging agent for gastric cancer diagnosis: glucose-regulated protein 78 binding peptide-guided 111In-labeled polymeric micelles

Increased expression of cellular membrane bound glucose-regulated protein 78 (GRP78) is considered to be one of the biomarkers for gastric cancers. Therefore, peptides or molecules with specific recognition to GRP78 can act as a guiding probe to direct conjugated imaging agents to localized cancers. Based on this rationale, GRP78-guided polymeric micelles were designed and manufactured for nuclear imaging detection of tumors. Thiolated GRP78 binding peptide (GRP78BP) was first labeled with maleimide-terminated poly(ethylene glycol)– poly(ɛ-caprolactone) and then mixed with diethylenetriaminepentaacetic acid (DTPA)-linked poly(ethylene glycol)–poly(ɛ-caprolactone) to form DTPA/GRP78BP-conjugated micelles. The coupling efficiency of micelles with radioisotope indium-111 (¹¹¹In) was measured and analyzed by instant thin layer chromatography. The coupling efficiency of DTPA-conjugated micelles and DTPA/GRP78BP-conjugated micelles with ¹¹¹In was 85% and 93%, respectively. For characterization and trace imaging, the radioisotope ¹¹¹In-targeting tumors were detected and imaged in a xenograft murine model using nano single photon emission computed tomography/computed tomography. The results revealed that the radioactive intensity measured in the animals administered with GRP78BP-guided ¹¹¹In-labeled micelles was statistically higher than that in animals administered with ¹¹¹In-labeled micelles, demonstrating that GRP78BP more than doubled the accumulation of micelles to the tumor tissue (P < 0.05). The results indicate that the gastric cancer biomarker GRP78 is a probing target in the application of nuclear imaging for tumor diagnosis. This novel GRP78BP-guided micelle agent may be applied in clinical practice to complement the histological diagnosis.

Targeting to overexpressed glucose-regulated protein 78 in gastric cancer discovered by 2D DIGE improves the diagnostic and therapeutic efficacy of micelles-mediated system

The survivals of gastric cancer (GC) patients are associated with early diagnosis and effective treatments. Therefore, it is urgent for the discovery of early GC biomarkers and tumor-targeting therapeutics. The aim of this study was to uncover putative tissue biomarkers of GC using 2D DIGE and then apply one of these specific markers in GC treatment. We found three putative biomarkers of GC with significant differences in expression level compared to adjacent normal tissue, including glucose-regulated protein 78 (GRP78) and glutathione s-transferase pi (GSTpi) with increased expression level, and alpha-1 antitrypsin (A1AT) with reduced expression level. The overexpressed GRP78 was used as a targeted protein for guiding the drugs to tumor cells, leading to more effective treatment for GC xenografts. Our results demonstrated that the designated GRP78-binding peptide based on the sequence, WIFPWIQL, was selectively prone to recognize and bind to GC MKN45 cells in vitro, and also improve the delivery efficiency of polymeric micelles-encapsulated drugs into tumor cells and displayed better therapeutic outcome in experimental animals. This strategy of GRP78-mediated drug targeting system may bring chemotherapeutic drugs with more precise targeting to tumor cells, leading to minimize side effects on patients after chemotherapy.

Utilization of lightflecks by seedlings of five dominant tree species of different subtropical forest successional stages under low-light growth conditions

We selected five typical tree species, including one early-successional species (ES) Pinus massoniana Lamb., two mid-successional species (MS) Schima superba Gardn. et Champ. and Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils. and two late-successional species (LS) Cryptocarya concinna Hance. and Acmena acuminatissima (BI.) Merr et Perry., which represent the plants at three successional periods in Dinghushan subtropical forest succession of southern China. Potted seedlings of the five species were grown under 12% of full sunlight for 36 months. The ES and MS showed the slowest and fastest responses to lightflecks, respectively, which correlated with the rate of stomatal opening. In contrast to P. massoniana and C. concinna, the other three species exhibited a high induction loss. Early-successional species showed the lowest specific leaf area and chlorophyll content, the highest photosynthetic capacity (A(max)) and respiratory carbon losses (R(d)). Compared with ES and MS, LS showed lower A(max) and R(d). The five tree species showed a similar chlorophyll a/b ratio after long-term low-light adaptations. On the other hand, LS had a relatively higher de-epoxidation state to protect themselves from excess light during lightflecks. Our results indicated that (i) slower responses to lightflecks could partially explain why ES species could not achieve seedling regeneration in low-light conditions; (ii) fast responses to lightflecks could partially explain why MS species could achieve seedling regeneration in low-light conditions; and (iii) smaller respiratory carbon losses might confer on the LS species a competitive advantage in low-light conditions.

INFLUENCE OF SUBSTITUTIONS IN ASYMMETRIC PORPHYRINS ON INTRACELLULAR UPTAKE, SUBCELLULAR LOCALIZATION AND PHOTOTOXICITY IN HELA CELLS

The asymmetric porphyrins with different substituents show various bioactivities in biomedical application. In this study, a series of asymmetric porphyrins with varying proportion of substituents, such as hydroxyphenyl and aminophenyl, were synthesized and characterized to evaluate their cell uptake, intracellular localization, cytotoxicities and phototoxicities in vitro. Among these synthesized porphyrins, 5-(4-aminophenyl)-10,15,20-tri-(4-hydroxyphenyl)-21,23H-porphyrin (porphyrin 5), which was mainly localized in mitochondria and with high quantum yields of singlet oxygen, is a potential candidate for photodynamic therapy. The effective phototoxicity of porphyrin 5 is mainly due to the higher extent in the cells and the selective mitochondria-localization. Comparing the partition coefficients of porphyrin derivatives, the best cellular uptake performs apparently with a partition coefficient (log p) ranging from about 1.7 to 1.9. In summary, higher quantum yields of singlet oxygen, and more specific mitochondrial localization of porphyrin 5 demonstrate its potential application in photodynamic therapy.

Synthesis and application of 188Re-MN-16ET/Lipiodol in a hepatocellular carcinoma animal model

INTRODUCTION

Hepatocellular carcinoma is the most common form of primary hepatic carcinoma. A new N(2)S(2) tetradentate ligand, N-[2-(triphenylmethyl)thioethyl]-3-aza-19-ethyloxycarbonyl-3-[2-(triphenylmethyl)thioethyl]octadecanoate (H(3)MN-16ET), was introduced and labeled with (188)Re to create (188)Re-MN-16ET in the Lipiodol phase. The potential of (188)Re-MN-16ET/Lipiodol for hepatoma therapy was evaluated in a hepatocellular carcinoma animal model of Sprague-Dawley rats implanted with the N1S1 cell line.

METHODS

Synthesis of H(3)MN-16ET was described, and characterization was identified by infrared, nuclear magnetic resonance and mass spectra. We compared the effects of transchelating agents (glucoheptonate or tartaric acid) and a reducing agent (stannous chloride) on the complexing of (188)Re-perrhenate and H(3)MN-16ET. Twenty-four rats implanted with hepatoma were injected with 3.7 MBq/0.1 ml of (188)Re-MN-16ET/Lipiodol or (188)Re-MN-16ET via transcatheter arterial embolization. Biodistribution experiments and single-photon emission computed tomography imaging were performed to investigate tumor accumulation.

RESULTS

H(3)MN-16ET was proved to easily conjugate with the Re isotope and showed good solubility in Lipiodol. The radiochemical purity of (188)Re-MN-16ET/Lipiodol with 10 mg tartaric acid and stannous chloride was shown to be more than 90%. The major distribution sites of (188)Re-MN-16ET in Sprague-Dawley rats were hepatoma and the liver. However, the radioactivity at the tumor site postadministered with (188)Re-MN-16ET was quickly decreased from 9.15±0.23 (at 1 h) to 2.71%±0.18% of injected dose/g (at 48 h). The biodistribution and micro-single-photon emission computed tomography/computed tomography image data showed that (188)Re-MN-16ET/Lipiodol was selectively retained at the tumor site, with 11.55±1.44, 13.16±1.46 and 10.67%±0.95% of injected dose/g at 1, 24 and 48 h postinjection, respectively. The radioactivity in normal liver tissue was high but significantly lower than that of the tumors.

CONCLUSION

H(3)MN-16ET is a suitable tetradentate ligand for (188)Re labeling. From the animal data, we suggest that (188)Re-MN-16ET/Lipiodol has the potential to be a therapeutic radiopharmaceutical for hepatoma treatment.

Multimodal image-guided photothermal therapy mediated by 188Re-labeled micelles containing a cyanine-type photosensitizer

Multifunctional micelles loaded with the near-infrared (NIR) dye and labeled with the radionuclide rhenium-188 ((188)Re) have been developed to provide multimodalities for NIR fluorescence and nuclear imaging and for photothermal therapy (PTT) of cancer. The NIR dye, IR-780 iodide, allowed the micelles to have dual functions in cancer NIR imaging and PTT. The (188)Re-labeled IR-780 micelles enabled imaging by NIR fluorescence and by microSPECT to guide the delivery of drugs and to monitor in real-time the tumor accumulation, intratumoral distribution, and kinetics of drug release, which serve as a basis of specific photothermal injury to the targeted tissue. We also investigated the biodistribution, generation of heat, and photothermal cancer ablation of IR-780 micelles of both in vitro and in vivo xenografts. Histopathology observed irreversible tissue damage, such as necrotic features, decreased cell proliferation, increased apoptosis of cells, and increased expression of heat shock proteins in the PTT-treated tumors. The (188)Re-labeled IR-780 micelles offer multifunctional modalities for NIR fluorescence and nuclear imaging and for PTT of cancer.

Development of thermosensitive poly(n-isopropylacrylamide-co-((2-dimethylamino) ethyl methacrylate))-based nanoparticles for controlled drug release

Thermosensitive nanoparticles based on poly(N-isopropylacrylamide-co-((2-dimethylamino)ethylmethacrylate)) (poly(NIPA-co-DMAEMA)) copolymers were successfully fabricated by free radical polymerization. The lower critical solution temperature (LCST) of the synthesized nanoparticles was 41 °C and a temperature above which would cause the nanoparticles to undergo a volume phase transition from 140 to 100 nm, which could result in the expulsion of encapsulated drugs. Therefore, we used the poly(NIPA-co-DMAEMA) nanoparticles as a carrier for the controlled release of a hydrophobic anticancer agent, 7-ethyl-10-hydroxy-camptothecin (SN-38). The encapsulation efficiency and loading content of SN-38-loaded nanoparticles at an SN-38/poly(NIPA-co-DMAEMA) ratio of 1/10 (D/P = 1/10) were about 80% and 6.293%, respectively. Moreover, the release profile of SN-38-loaded nanoparticles revealed that the release rate at 42 °C (above LCST) was higher than that at 37 °C (below LCST), which demonstrated that the release of SN-38 could be controlled by increasing the temperature. The cytotoxicity of the SN-38-loaded poly(NIPA-co-DMAEMA) nanoparticles was investigated in human colon cancer cells (HT-29) to compare with the treatment of an anticancer drug, Irinotecan(®) (CPT-11). The antitumor efficacy evaluated in a C26 murine colon tumor model showed that the SN-38-loaded nanoparticles in combination with hyperthermia therapy efficiently suppressed tumor growth. The results indicate that these thermo-responsive nanoparticles are potential carriers for controlled drug delivery.

Development of pH sensitive 2-(diisopropylamino)ethyl methacrylate based nanoparticles for photodynamic therapy

Photodynamic therapy is an effective treatment for tumors that involves the administration of light-activated photosensitizers. However, most photosensitizers are insoluble and non-specific. To target the acid environment of tumor sites, we synthesized three poly(ethylene glycol) methacrylate-co-2-(diisopropylamino)ethyl methacrylate (PEGMA-co-DPA) copolymers capable of self-assembly to form pH sensitive nanoparticles in an aqueous environment, as a means of encapsulating the water-insoluble photosensitizer, meso-tetra(hydroxyphenyl)chlorin (m-THPC). The critical aggregation pH of the PEGMA-co-DPA polymers was 5.8-6.6 and the critical aggregation concentration was 0.0045-0.0089 wt% at pH 7.4. Using solvent evaporation, m-THPC loaded nanoparticles were prepared with a high drug encapsulation efficiency (approximately 89%). Dynamic light scattering and transmission electron microscopy revealed the spherical shape and 132 nm diameter of the nanoparticles. The in vitro release rate of m-THPC at pH 5.0 was faster than at pH 7.0 (58% versus 10% m-THPC released within 48 h, respectively). The in vitro photodynamic therapy efficiency was tested with the HT-29 cell line. m-THPC loaded PEGMA-co-DPA nanoparticles exhibited obvious phototoxicity in HT-29 colon cancer cells after light irradiation. The results indicate that these pH sensitive nanoparticles are potential carriers for tumor targeting and photodynamic therapy.

Dual chemotherapy and photodynamic therapy in an HT-29 human colon cancer xenograft model using SN-38-loaded chlorin-core star block copolymer micelles

Chlorin-core star-shaped block copolymer (CSBC) may self-assemble to form micelles, which act as nanosized photosensitizing agents for photodynamic therapy (PDT) and further encapsulate hydrophobic drugs. This functionalized micellar delivery system is a potential dual carrier for the synergistic combination of photodynamic therapy and chemotherapy for the treatment of cancer. In this study, SN-38 encapsulated CSBC micelles were successfully prepared using a lyophilization-hydration method. Our results show that the prolonged plasma residence time of SN-38/CSBC micelles as compared with free CPT-11 permit increased tumor accumulation and consequently, improved antitumor activity. The combined effects of SN-38/CSBC micelles with PDT were evaluated in an HT-29 human colon cancer xenograft model. Interesting, SN-38/CSBC-mediated PDT synergistically inhibited tumor growth, resulting in up to 60% complete regression of well-established tumors after 3 treatments. These treatments also decreased the microvessel density (MVD) and cell proliferation within the subcutaneous tumors. Therefore, this SN-38/CBSC delivery system has the potential to offer dual therapies for the synergistic combination of PDT and chemotherapy for the treatment of cancer.

Self-assembled star-shaped chlorin-core poly(epsilon-caprolactone)-poly(ethylene glycol) diblock copolymer micelles for dual chemo-photodynamic therapies

Amphiphilic 4-armed star-shaped chlorin-core diblock copolymers based on methoxy poly(ethylene glycol) (mPEG) and poly (epsilon-caprolactone) (PCL) were synthesized and characterized in this study. The synthesized photosensitizer-centered amphiphilic star block copolymer that forms assembled micelle-like structures can be used in a photodynamic therapy (PDT)-functionalized drug delivery system. Moreover, the hydrophobic chemotherapeutic agent, paclitaxel, can be trapped in the hydrophobic inner core of micelles. In our results, the star-polymer-formed micelle exhibited efficient singlet oxygen generation, whereas the hydrophobic photosensitizer failed due to aggregation in aqueous solution. The chlorin-core micelle without paclitaxel loading exhibited obvious phototoxicity in MCF-7 breast cancer cells with 7J/cm2 or 14J/cm2 light irradiation at a chlorin concentration of 125microg/ml. After paclitaxel loading, the size of micelle increased from 71.4nm to 103.2nm. Surprisingly, these micelles were found to improve the cytotoxicity of paclitaxel significantly in MCF-7 cells after irradiation through a synergistic effect evaluated by median effect analysis. This functionalized micellar delivery system is a potential dual carrier for the synergistic combination of photodynamic therapy and chemotherapy for the treatment of cancer.

Non-toxic phototriggered gene transfection by PAMAM-porphyrin conjugates

Development of controllable and non-toxic gene transfection systems is a core issue in gene therapy. Photochemical internalization, an innovative strategy in cytosolic release, provides us with an opportunity to develop a light-inducible gene delivery system. In this study, a novel photochemical internalization (PCI)-mediated gene delivery system was synthesized by surface modification of polyamidoamine (PAMAM) dendrimers via 5,10,15-tri(4-acetamidophenyl)-20-mono(4-carboxyl-phenyl)porphyrin (TAMCPP) conjugated to the generation 4 PAMAM dendrimer (G4). This water-soluble PAMAM-TAMCPP conjugate was characterized for cell viability, phototoxicity, DNA complexation, and in vitro transfection activity. The results show that TAMCPP conjugation did not increase the cytotoxicity of the PAMAM dendrimer below 20 microM, but significantly induced cell death after suitable irradiation. Under almost non-toxic G4-TAMCPP-mediated PCI treatment, the expression of green fluorescent protein determined by flow cytometry could be markedly enhanced in HeLa cells. Therefore, the G4-TAMCPP conjugate had an inducible and effective gene transfection activity, and showed considerable potential as a bimodal biomaterial for PCI-mediated gene therapy.

Doxorubicin delivery by polyamidoamine dendrimer conjugation and photochemical internalization for cancer therapy

Coupling anticancer drugs to synthetic polymers is a promising approach to improve the efficacy and reduce the side effects of these drugs. The pH-activated polymer has been demonstrated to be a successful drug delivery vehicle system, whereas the photochemical internalization (PCI) was invented for site-specific delivery of membrane impermeable macromolecules from endocytic vesicles into the cytosol. In this study, doxorubicin (DOX) was conjugated to polyamidoamine (PAMAM) dendrimers via pH-sensitive and -insensitive linkers and was combined with different PCI strategies to evaluate the cytotoxic effects. Our results showed that both PCI strategies significantly improved the cytotoxicity of free DOX on Ca9-22 cells at higher concentrations. The 'light after' PCI treatment was efficient in releasing DOX from the PAMAM-hyd-DOX conjugates, resulted in more nuclear accumulation of DOX and more cell death through synergistic effects. On the other hand, antagonism was observed when 'light before' PCI combined with PAMAM-hyd-DOX conjugate. The distribution of PAMAM-amide-DOX was mainly cytosolic with or without PCI treatments. Both PCI strategies failed to improve the cytotoxicity of PAMAM-amide-DOX conjugates. Our results provide invaluable information in the future design of drug-polymer complexes for multi-modality cancer treatments.

In vivo measurement of the elastic modulus of the human periodontal ligament

The present study was designated to determine the elastic properties of the periodontal ligament (PDL) in human subjects. A maxillary central incisor was experimentally translated so that stress or strain could be uniformly distributed in the PDL by applying a single force passing through the center of resistance. Displacements were measured under different magnitudes of load using a magnet-magnetic sensing system. From the load-displacement relations, Young's modulus of the PDL was calculated. The values determined were approximately 0.12 MPa under load ranging from 0 to 0.5 N, 0.25 MPa within the range of 0.5-1.0 N, 0.44 MPa under load 1.0-1.5 N, and between 0.69 and 0.96 MPa with 1.5-2.0 N. The values of Young's moduli increased almost exponentially with the increment of load due to a non-linear elasticity of the PDL.