A Hyaluronic Acid Demilune Scaffold and Polypyrrole-Coated Fibers Carrying Embedded Human Neural Precursor Cells and Curcumin for Surface Capping of Spinal Cord Injuries.

Tissue engineering, including cell transplantation and the application of biomaterials and bioactive molecules, represents a promising approach for regeneration following spinal cord injury (SCI). We designed a combinatorial tissue-engineered approach for the minimally invasive treatment of SCI-a hyaluronic acid (HA)-based scaffold containing polypyrrole-coated fibers (PPY) combined with the RAD16-I self-assembling peptide hydrogel (Corning® PuraMatrix™ peptide hydrogel (PM)), human induced neural progenitor cells (iNPCs), and a nanoconjugated form of curcumin (CURC). In vitro cultures demonstrated that PM preserves iNPC viability and the addition of CURC reduces apoptosis and enhances the outgrowth of Nestin-positive neurites from iNPCs, compared to non-embedded iNPCs. The treatment of spinal cord organotypic cultures also demonstrated that CURC enhances cell migration and prompts a neuron-like morphology of embedded iNPCs implanted over the tissue slices. Following sub-acute SCI by traumatic contusion in rats, the implantation of PM-embedded iNPCs and CURC with PPY fibers supported a significant increase in neuro-preservation (as measured by greater ßIII-tubulin staining of neuronal fibers) and decrease in the injured area (as measured by the lack of GFAP staining). This combination therapy also restricted platelet-derived growth factor expression, indicating a reduction in fibrotic pericyte invasion. Overall, these findings support PM-embedded iNPCs with CURC placed within an HA demilune scaffold containing PPY fibers as a minimally invasive combination-based alternative to cell transplantation alone.

A targeted polypeptide-based nanoconjugate as a nanotherapeutic for alcohol-induced neuroinflammation.

Alcohol abuse induces the expression of inflammatory mediators by activating the immune receptors to trigger neuroinflammation and brain damage; however, therapies that reduce neuroimmune system activation may protect against alcohol's damaging effects. Curcuminoids possess anti-inflammatory properties but suffer from low bioavailability; therefore, we designed a new receptor-targeted biodegradable star-shaped crosslinked polypeptide polymer that bears propargylamine moieties and bisdemethoxycurcumin (StClPr-BDMC-ANG) as an enhanced anti-inflammatory therapeutic that penetrates the blood-brain-barrier and ameliorates alcohol-induced neuroinflammation. StClPr-BDMC-ANG administration maintains the viability of primary glia and inhibits the ethanol-induced upregulation of crucial inflammatory mediators in the prefrontal and medial cortex in a mouse model of chronic ethanol consumption. StClPr-BDMC-ANG treatment also suppresses the ethanol-mediated downregulation of microRNAs known to negatively modulate neuroinflammation in the brain cortex (miRs 146a-5p and let-7b-5p). In summary, our results demonstrate the attenuation of alcohol-induced neuroinflammation by an optimized and targeted polypeptide-based nanoconjugate of a curcuminoid.

Near-Infrared Activatable Phthalocyanine-Poly-L-Glutamic Acid Conjugate: Enhanced in Vivo Safety and Antitumor Efficacy toward an Effective Photodynamic Cancer Therapy.

We previously developed a new zinc(II) phthalocyanine (ZnPc) derivative (Pc 1) conjugated to poly-L-glutamic acid (PGA) (1-PG) to address the limitations of ZnPc as part of an antitumor photodynamic therapy approach, which include hydrophobicity, phototoxicity, and nonselectivity in biodistribution and tumor targeting. During this study, we discovered that 1-PG possessed high near-infrared (NIR) light absorptivity (λmax = 675 nm), good singlet oxygen generation efficiency in an aqueous environment, and enhanced photocytotoxic efficacy and cancer cell uptake in vitro. In the current study, we discovered that 1-PG accumulated in 4T1 mouse mammary tumors, with a retention time of up to 48 h. Furthermore, as part of an antitumor PDT, low dose 1-PG (2 mg of Pc 1 equivalent/kg) induced a greater tumor volume reduction (-74 ± 5%) when compared to high dose ZnPc (8 mg/kg, -50 ± 12%). At higher treatment doses (8 mg of Pc 1 equivalent/kg), 1-PG reduced tumor volume maximally (-91 ± 6%) and suppressed tumor size to a minimal level for up to 15 days. The kidney, liver, and lungs of the mice treated with 1-PG (both low and high doses) were free from 4T1 tumor metastasis at the end of the study. Telemetry-spectral-echocardiography studies also revealed that PGA (65 mg/kg) produced insignificant changes to the cardiovascular physiology of Wistar-Kyoto rats when administered in vivo. Results indicate that PGA displays an excellent cardiovascular safety profile, underlining its suitability for application as a nanodrug carrier in vivo. These current findings indicate the potential of 1-PG as a useful photosensitizer candidate for clinical PDT.

Integrin-targeted nano-sized polymeric systems for paclitaxel conjugation: a comparative study.

The generation of rationally designed polymer therapeutics via the conjugation of low molecular weight anti-cancer drugs to water-soluble polymeric nanocarriers aims to improve the therapeutic index. Here, we focus on applying polymer therapeutics to target two cell compartments simultaneously - tumour cells and angiogenic endothelial cells. Comparing different polymeric backbones carrying the same therapeutic agent and targeting moiety may shed light on any correlation between the choice of polymer and the anti-cancer activity of the conjugate. Here, we compared three paclitaxel (PTX)-bound conjugates with poly-l-glutamic acid (PGA, 4.9 mol%), 2-hydroxypropylmethacrylamide (HPMA, 1.2 mol%) copolymer, or polyethyleneglycol (PEG, 1:1 conjugate). PGA and HPMA copolymers are multivalent polymers that allow the conjugation of multiple compounds within the same polymer backbone, while PEG is a bivalent commercially available Food and Drug Administration (FDA)-approved polymer. We further conjugated PGA-PTX and PEG-PTX with the integrin αvß3-targeting moiety RGD (5.5 mol% and 1:1 conjugate, respectively). We based our selection on the overexpression of integrin αvß3 on angiogenic endothelial cells and several types of cancer cells. Our findings suggest that the polymer structure has major effect on the conjugate's activity on different tumour compartments. A multivalent PGA-PTX-E-[c(RGDfK)2] conjugate displayed a stronger inhibitory effect on the endothelial compartment, showing a 50% inhibition of the migration of human umbilical vein endothelial cell cells, while a PTX-PEG-E-[c(RGDfK)2] conjugate possessed enhanced anti-cancer activity on MDA-MB-231 tumour cells (IC50 = 20 nM versus IC50 300 nM for the PGA conjugate).

MiR-187 Targets the Androgen-Regulated Gene ALDH1A3 in Prostate Cancer.

miRNAs are predicted to control the activity of approximately 60% of all protein-coding genes participating in the regulation of several cellular processes and diseases, including cancer. Recently, we have demonstrated that miR-187 is significantly downregulated in prostate cancer (PCa) and here we propose a proteomic approach to identify its potential targets. For this purpose, PC-3 cells were transiently transfected with miR-187 precursor and miRNA mimic negative control. Proteins were analyzed by a two-dimensional difference gel electrophoresis (2D-DIGE) and defined as differentially regulated if the observed fold change was ±1.06. Then, MALDI-TOF MS analysis was performed after protein digestion and low abundance proteins were identified by LC-MS/MS. Peptides were identified by searching against the Expasy SWISS PROT database, and target validation was performed both in vitro by western blot and qRT-PCR and in clinical samples by qRT-PCR, immunohistochemistry and ELISA. DIGE analysis showed 9 differentially expressed spots (p<0.05) and 7 showed a down-regulated expression upon miR-187 re-introduction. Among these targets we identified aldehyde dehydrogenase 1A3 (ALDH1A3). ALDH1A3 expression was significantly downregulated in PC3, LNCaP and DU-145 cells after miR-187 re-introduction. Supporting these data, the expression of ALDH1A3 was found significantly (p<0.0001) up-regulated in PCa samples and inversely correlated (p<0.0001) with miR-187 expression, its expression being directly associated with Gleason score (p = 0.05). The expression of ALDH1A3 was measured in urine samples to evaluate the predictive capability of this biomarker for the presence of PCa and, at a signification level of 10%, PSA and also ALDH1A3 were significantly associated with a positive biopsy of PCa. In conclusion, our data illustrate for the first time the role of ALDH1A3 as a miR-187 target in PCa and provide insights in the utility of using this protein as a new biomarker for PCa.

Biocompatibility reduces inflammation-induced apoptosis in mesothelial cells exposed to peritoneal dialysis fluid.

BACKGROUND/AIMS: Peritonitis is a major complication that arises out of peritoneal dialysis (PD), leading to death and loss of mesothelium and peritoneal injury, which may impede PD. We studied the combined impact of inflammatory mediators and PD fluids on mesothelial cell death. METHODS: Cultured human mesothelial cells. RESULTS: Inflammatory cytokines (TNF-α and interferon-γ) cooperate with bioincompatible PD fluids containing high glucose degradation product (GDP) concentrations to promote mesothelial cell death. Thus, the inflammatory cytokine cocktail induced a higher rate of death in cells cultured in high GDP PD fluid than in low GDP PD fluid or cell culture medium (cell death expressed as % hypodiploid cells: TNF-α and interferon-γ in RPMI: 14.15 ± 1.68, TNF-α and interferon-γ in 4.25% low GDP PD fluid 13.16 ± 3.29, TNF-α and interferon-γ in 4.25% high GDP PD fluid 25.88 ± 2.18%, p < 0.05 vs. the other two groups). BclxL BH4 peptides, Apaf-1 inhibition or caspase inhibition failed to protect from apoptosis induced by the combination of inflammatory cytokines and bioincompatible PD fluids, although they protected from other forms of mesothelial cell apoptosis. CONCLUSION: Inflammation cooperates with high GDP PD fluids to promote mesothelial cell death, which is resistant to several therapeutic approaches. This information provides a framework for selection of PD fluid during peritonitis.

A nanoconjugate Apaf-1 inhibitor protects mesothelial cells from cytokine-induced injury.

BACKGROUND: Inflammation may lead to tissue injury. We have studied the modulation of inflammatory milieu-induced tissue injury, as exemplified by the mesothelium. Peritoneal dialysis is complicated by peritonitis episodes that cause loss of mesothelium. Proinflammatory cytokines are increased in the peritoneal cavity during peritonitis episodes. However there is scarce information on the modulation of cell death by combinations of cytokines and on the therapeutic targets to prevent desmesothelization. METHODOLOGY: Human mesothelial cells were cultured from effluents of stable peritoneal dialysis patients and from omentum of non-dialysis patients. Mesothelial cell death was studied in mice with S. aureus peritonitis and in mice injected with tumor necrosis factor alpha and interferon gamma. Tumor necrosis factor alpha and interferon gamma alone do not induce apoptosis in cultured mesothelial cells. By contrast, the cytokine combination increased the rate of apoptosis 2 to 3-fold over control. Cell death was associated with the activation of caspases and a pancaspase inhibitor prevented apoptosis. Specific caspase-8 and caspase-3 inhibitors were similarly effective. Co-incubation with both cytokines also impaired mesothelial wound healing in an in vitro model. However, inhibition of caspases did not improve wound healing and even impaired the long-term recovery from injury. By contrast, a polymeric nanoconjugate Apaf-1 inhibitor protected from apoptosis and allowed wound healing and long-term recovery. The Apaf-1 inhibitor also protected mesothelial cells from inflammation-induced injury in vivo in mice. CONCLUSION: Cooperation between tumor necrosis factor alpha and interferon gamma contributes to mesothelial injury and impairs the regenerative capacity of the monolayer. Caspase inhibition attenuates mesothelial cell apoptosis but does not facilitate regeneration. A drug targeting Apaf-1 allows protection from apoptosis as well as regeneration in the course of inflammation-induced tissue injury.

Synthesis and biological evaluation of new 1,5-diazaanthraquinones with cytotoxic activity.

A series of 1,5-diazaanthraquinone derivatives was synthesized and their in vitro cytotoxic activities were evaluated against several human cancer cell lines. The 1,5-diazaanthraquinone chromophore has been synthesized either on the basis of hetero Diels-Alder reactions involving different quinoline-5,8-diones and alpha,beta-unsaturated aldehyde N,N-dimethylhydrazones or by thermolysis of different arylaminomethylene Meldrum's acid derivatives. Some of these compounds showed cytotoxic activity comparable to that of mitoxantrone against most of the cell lines tested. Compounds 20, 30, 31 and 37 were 4-54 times more potent that mitoxantrone against A549, H116, PSN1 and T98G cancer cell lines but, interestingly, they were 3-16 times less potent against the human breast carcinoma SKBR3. Some structure-activity relationships are described, the most significant one being the increase in cytotoxicity resulting from the introduction of a halogen atom at the C-4 position.

Synthesis and structure-activity relationships of 1,5-diazaanthraquinones as antitumour compounds.

1,5-Diazaanthraquinone derivatives were synthesized employing single and double hetero Diels-Alder strategies. Their in vitro antitumour activity was assayed using three cell lines. Some of these compounds, specially those bearing methyl or ethyl groups at the C-3,7 positions or chloro at C-4 and methyl at C-7, showed IC(50) values in the 10(-8)M range for human lung carcinoma and human melanoma, which makes them attractive candidates for further development as anticancer agents.