An Antitumor Bis(N-Heterocyclic Carbene)Platinum(II) Complex That Engages Asparagine Synthetase as an Anticancer Target.

New anticancer platinum(II) compounds with distinctive modes of action are appealing alternatives to combat the drug resistance and improve the efficacy of clinically used platinum chemotherapy. Herein, we describe a rare example of an antitumor PtII complex targeting a tumor-associated protein, rather than DNA, under cellular conditions. Complex [(bis-NHC)Pt(bt)]PF6 (1 a; Hbt=1-(3-hydroxybenzo[b]thiophen-2-yl)ethanone) overcomes cisplatin resistance in cancer cells and displays significant tumor growth inhibition in mice with higher tolerable doses compared to cisplatin. The cellular Pt species shows little association with DNA, and localizes in the cytoplasm as revealed by nanoscale secondary ion mass spectrometry. An unbiased thermal proteome profiling experiment identified asparagine synthetase (ASNS) as a molecular target of 1 a. Accordingly, 1 a treatment reduced the cellular asparagine levels and inhibited cancer cell proliferation, which could be reversed by asparagine supplementation. A bis-NHC-ligated Pt species generated from the hydrolysis of 1 a forms adducts with thiols and appears to target an active-site cysteine of ASNS.

A Multifunctional Hydrogel Delivers Gold Compound and Inhibits Human Lung Cancer Xenograft.

PURPOSE: Interpenetrating network system (IPN), consisting of polyethylene glycol (PEG) -diacrylate (PEGdA) and modified gelatin, is a biocompatible and biodegradable hydrogel and has been studied for the local delivery of bioactive molecules and drugs. Gold(III) porphyrin(AuP) is a stable metal compound in the development for anticancer application when administered systemically. The aim of this work is to develop a novel formulation for AuP based on IPN for local delivery. METHODS: IPN loaded with AuP hydrogel was optimized and synthesized. Drug release kinetics, cytotoxicity against tumor cells, and antitumor activity in lung cancer bearing nude mice were studied. RESULTS: AuP released from the IPN followed a first order kinetics in vitro. The AuP loaded IPN showed higher cytotoxicity against human lung cancer cell lines compared to IPN only. In mice bearing human lung cancer xenograft, AuP loaded IPN inhibited tumor growth and reduced angiogenesis. No sign of systemic toxicity was observed for all treatment groups. CONCLUSION: AuP loaded IPN provides an improved formulation over systemic delivery for tumor inhibition to complement surgical intervention. Graphical Abstract Injectable multifunctional matrix of polyethylene glycol and gelatin derivatives for the delivery of gold porphyrinto inhibit tumor growth.

Cyclometalated Gold(III) Complexes Containing N-Heterocyclic Carbene Ligands Engage Multiple Anti-Cancer Molecular Targets.

Metal N-heterocyclic carbene (NHC) complexes are a promising class of anti-cancer agents displaying potent in vitro and in vivo activities. Taking a multi-faceted approach employing two clickable photoaffinity probes, herein we report the identification of multiple molecular targets for anti-cancer active pincer gold(III) NHC complexes. These complexes display potent and selective cytotoxicity against cultured cancer cells and in vivo anti-tumor activities in mice bearing xenografts of human cervical and lung cancers. Our experiments revealed the specific engagement of the gold(III) complexes with multiple cellular targets, including HSP60, vimentin, nucleophosmin, and YB-1, accompanied by expected downstream mechanisms of action. Additionally, PtII and PdII analogues can also bind the cellular proteins targeted by the gold(III) complexes, uncovering a distinct pincer cyclometalated metal-NHC scaffold in the design of anti-cancer metal medicines with multiple molecular targets.

Silver nanoparticle treatment ameliorates biliary atresia syndrome in rhesus rotavirus inoculated mice.

Biliary atresia (BA) is a neonatal biliary system disease closely associated with viral infection and bile duct inflammation. Silver nanoparticles (AgNps) have previously revealed antiviral and anti-inflammatory properties. In this study, we have investigated the effects of AgNps in the treatment of the Rhesus rotavirus inoculation induced BA in mice. The morphology, liver histopathology, clinical biochemistry examination, and inflammatory cells were analyzed in BA mice. Results indicated that AgNps could significantly increase the survival rate of BA mice, and reduce jaundice and weight lost and the liver enzymes and bilirubin metabolism clinical parameters were close to the normal levels. Diminished numbers of NK cells were observed by flow cytometry analysis and immunohistochemical staining. Furthermore, the viral load was reduced and transcripts for TGF-ß mRNA were augmented after AgNps treatment. Collectively, our results suggest that AgNps treatment has beneficial effects on the BA mouse model partially through upregulation of TGF-ß.

A Macrocyclic Ruthenium(III) Complex Inhibits Angiogenesis with Down-Regulation of Vascular Endothelial Growth Factor Receptor-2 and Suppresses Tumor Growth In Vivo.

A macrocyclic ruthenium(III) complex [RuIII (N2 O2 )Cl2 ]Cl (Ru-1) is reported as an inhibitor of angiogenesis and an anti-tumor compound. The complex is relatively non-cytotoxic towards endothelial and cancer cell lines in vitro, but specifically inhibited the processes of angiogenic endothelial cell tube formation and cancer cell invasion. Moreover, compared with known anti-cancer ruthenium complexes, Ru-1 is distinct in that it suppressed the expression of vascular endothelial growth factor receptor-2 (VEGFR2), and the associated downstream signaling that is crucial to tumor angiogenesis. In addition, in vivo studies showed that Ru-1 inhibited angiogenesis in a zebrafish model and suppressed tumor growth in nude mice bearing cancer xenografts.

Silver nanoparticles promote osteogenesis of mesenchymal stem cells and improve bone fracture healing in osteogenesis mechanism mouse model.

The potential use of osteo-conducive biomaterials in the promotion of bone fracture healing has attracted wide attention. This study investigated if silver nanoparticles (AgNps) could promote the proliferation and osteogenesis of mesenchymal stem cells (MSCs), and improve bone fracture healing. We showed that AgNps promoted MSCs' proliferation and osteogenic differentiation in vitro. Using a mouse femoral facture model, AgNps encapsulated in collagen promoted the formation of fracture callus, and induced early closure of the fracture gap. AgNps may promote the formation of the callus and the subsequent end joining of the fracture bone via multiple routes: (i) chemo-attraction of MSCs and fibroblasts to migrate to the fracture site; (ii) induction of the proliferation of MSCs; (iii) induction of osteogenic differentiation of MSCs via induction/activation of TGF-ß/BMP signaling in MSCs. We concluded that AgNps might be beneficial as an adjunct treatment for bone fracture healing clinically. FROM THE CLINICAL EDITOR: Silver nanoparticles are widely used in wound management in the clinical setting. In this article, the authors demonstrated a novel application in that these nanoparticles were efficient in promoting osteoblastic differentiation in both in-vitro and in-vivo studies. The findings may provide a new treatment direction for bone fracture in the future.

Lipophilic-formulated gold porphyrin nanoparticles for chemotherapy.

Lipophilic formulation is an invaluable technique for the delivery of cancer drugs. Incorporation of poorly soluble and toxic compounds into a lipophilic carrier vehicle improves both the stability and compatibility in blood and body fluids. Currently, although a large proportion of novel cancer drugs are poorly water soluble, most existing drug carriers are only able to encapsulate hydrophilic drugs. As the ultimate goal of drug delivery (in particular cancer drug delivery) is to achieve high therapeutic effect with minimal toxicity, it would thus be beneficial to invest substantial efforts in the development of lipophilic carrier systems. Here we describe our technique to synthesize a lipophilic carrier for hydrophobic and toxic potent cancer drugs, such as gold(III) porphyrin.

Enhancement of anticancer efficacy using modified lipophilic nanoparticle drug encapsulation.

BACKGROUND: Development of anticancer drugs is challenging. Indeed, much research effort has been spent in the development of new drugs to improve clinical outcomes with minimal toxicity. We have previously reported that a formulation of lipid gold porphyrin nanoparticles reduced systemic drug toxicity when compared with free gold porphyrin. In this study, we investigated the delivery and treatment efficiency of PEG surface-modified lipid nanoparticles as a carrier platform. METHODS: We encapsulated antitumor drugs into PEG-modified lipid nanoparticles and these were characterized by size, zeta potential, and encapsulation efficiency. The delivery efficiency into tumor tissue was evaluated using a biodistribution study. To evaluate antitumor efficacy, gold porphyrin or camptothecin (a DNA topoisomerase I inhibitor) were encapsulated and compared using an in vivo neuroblastoma (N2A) model. RESULTS: We showed that drug encapsulation into PEG-modified lipid nanoparticles enhanced the preferential uptake in tumor tissue. Furthermore, higher tumor killing efficiency was observed in response to treatment with PEG-modified lipid nanoparticles encapsulating gold porphyrin or camptothecin when compared with free gold porphyrin or free camptothecin. The in vivo antitumor effect was further confirmed by study of tumor inhibition and positive apoptosis activity. Surface modification of lipophilic nanoparticles with PEG increased the efficiency of drug delivery into tumor tissue and subsequently more effective antitumor activity. CONCLUSION: This specific design of a chemotherapeutic agent using nanotechnology is important in the development of a safe and effective drug in cancer therapy.

ω-3 fatty acids suppress inflammatory cytokine production by macrophages and hepatocytes.

OBJECTIVE: Long-term total parenteral nutrition (TPN) in children is often complicated by parental nutrition-associated liver disease and may even lead to liver failure. Recently, the addition of ω-3 fatty acids to TPN has been shown to reduce the risk of parental nutrition-associated liver disease. The purpose of this study was to explore the anti-inflammatory effects of ω-3 fatty acids (eicosapentaenoic acid [EPA]) to demonstrate the protection of the liver against hepatic steatosis and damage. MATERIALS AND METHODS: Lipopolysaccharide (LPS) and prostaglandin E(2) (PGE(2)) were used to stimulate human macrophages and hepatocytes (THLE-3) to induce in vitro inflammatory condition. The cells were then incubated with either ω-3 (EPA) or ω-6 (arachidonic acid) fatty acids. Supernatants were collected at different time points for the measurement of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10) using enzyme-linked immunosorbent assay. Furthermore, pretreated macrophages by LPS stimulation and after incubation with EPA were added to prestimulated hepatocytes for the subsequent measurement of cytokine response. RESULTS: Eicosapentaenoic acid effectively reduced LPS-induced or PGE(2)-induced TNF-α and IL-6 expression, and increased IL-10 expression significantly when compared with arachidonic acid. Furthermore, supernatant collected after co-culturing EPA with macrophages also suppressed the levels of TNF-α and IL-6 in hepatocytes. This would suggest that EPA not only had an anti-inflammatory effect on macrophages and hepatocytes directly, it could indirectly reduce hepatocyte inflammation through activated macrophages. CONCLUSIONS: The addition of ω-3 fatty acids in TPN suppresses the inflammatory response via direct and indirect routes. The findings may help explain the clinical benefits of EPA in pediatric patients receiving long-term TPN.

Silver nanoparticles mediate differential responses in keratinocytes and fibroblasts during skin wound healing.

With advances in nanotechnology, pure silver has been recently engineered into nanometer-sized particles (diameter <100 nm) for use in the treatment of wounds. In conjunction with other studies, we previously demonstrated that the topical application of silver nanoparticles (AgNPs) can promote wound healing through the modulation of cytokines. Nonetheless, the question as to whether AgNPs can affect various skin cell types--keratinocytes and fibroblasts--during the wound-healing process still remains. Therefore, the aim of this study was to focus on the cellular response and events of dermal contraction and epidermal re-epithelialization during wound healing under the influence of AgNPs; for this we used a full-thickness excisional wound model in mice. The wounds were treated with either AgNPs or control with silver sulfadiazine, and the proliferation and biological events of keratinocytes and fibroblasts during healing were studied. Our results confirm that AgNPs can increase the rate of wound closure. On one hand, this was achieved through the promotion of proliferation and migration of keratinocytes. On the other hand, AgNPs can drive the differentiation of fibroblasts into myofibroblasts, thereby promoting wound contraction. These findings further extend our current knowledge of AgNPs in biological and cellular events and also have significant implications for the treatment of wounds in the clinical setting.

The cytotoxic effects of lipidic formulated gold porphyrin nanoparticles for the treatment of neuroblastoma.

OBJECTIVE: Nanotechnology has been identified as a promising platform in the improvement of the design and development of drug delivery systems. In the present study we investigated the potential of lipidic nanoparticles consisting of gold porphyrin for the treatment of neuroblastoma. MATERIALS AND METHODS: To characterize the size of the lipidic gold porphyrin nanoparticles, we used transmission electron microscopy (TEM). The in vitro cytotoxic effect on neuroblastoma activity was examined using XTT cell proliferation assay, then IC50 values were calculated. In vivo safety and toxicity were studied using intraperitoneal injection of gold porphyrin nanoparticles into normal animals. Finally, tumor size measurement and animal survival were studied to investigate the therapeutic effect of lipidic gold porphyrin nanoparticles on neuroblastoma growth. RESULTS: We found that incorporation of gold porphyrin into lipidic nanoparticles resulted in a 16-fold increase in size. Subsequent in vitro and in vivo cytotoxicity studies further showed that the lipidic gold porphyrin nanoparticles could decrease systemic toxicity, as well as inhibiting tumor growth following administration into the neuroblastoma bearing mice. CONCLUSION: The delivery of lipidic gold porphyrin nanoparticles by incorporation with lipidic formulation is feasible approach to treat neuroblastoma. We await further studies to evaluate tumor killing kinetics.

Electroporatic delivery of TGF-beta1 gene works synergistically with electric therapy to enhance diabetic wound healing in db/db mice.

Electrical stimulation (ES) is a therapeutic treatment for wound healing. Electroporation, a type of ES, is a well-established method for gene delivery. We hypothesize that proper conditions can be found with which both electrical and gene therapies can be additively applied to treat diabetic wound healing. For the studies of transforming growth factor-beta1 (TGF-beta1) local expression and therapeutic effects, full thickness excisional wound model of db/db mice was used, we measured TGF-beta1 cytokine level at 24 h postwounding and examined wounds histologically. Furthermore, wound closure was evaluated by wound-area measurements at each day for 14 d. We found that syringe electrodes are more effective than the conventional caliper electrodes. Furthermore, diabetic skin was more sensitive to the electroporative damage than the normal skin. The optimal condition for diabetic skin was six pulses of 100 V per cm for 20 ms. Under such condition, the healing rate of electrically treated wound was significantly accelerated. Furthermore, when TGF-beta1 gene was delivered by electric pulses, the healing rate was further enhanced. Five to seven days postapplication of intradermal injection of plasmid TGF-beta1 followed by electroporation, the wound bed showed an increased reepithelialization rate, collagen synthesis, and angiogenesis. The data indicates that indeed the electric effect and gene effect work synergistic in the genetically diabetic model.

Controlled gene delivery system based on thermosensitive biodegradable hydrogel.

PURPOSE: Currently, most pDNA delivery systems based on synthetic polymers are either nonbiodegradable or not sensitive to the release environment. The primary objective of this study was to develop and evaluate an aqueous-based, thermosensitive, biodegradable and biocompatible triblock copolymer to control pDNA delivery in vitro and in vivo. METHODS: The triblock copolymers, poly[ethylene glycol-b-(D, L-lactic acid-co-glycol acid)-b-ethylene glycol] (PEG-PLGA-PEG), were synthesized as previously described. The molecular weight and polydispersity of PEG-PLGA-PEG were monitored by gel permeation chromatography (GPC). The cytotoxicity of PEG-PLGA-PEG was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The release of 32P-labeled pDNA entrapped in aqueous dispersion of PEG-PLGA-PEG in 0.1 mol/L sodium phosphate buffer solution (pH 7.4) was studied at 37 degrees C under agitation. Gene transfection efficiency was evaluated in a skin wound model in CD-1 mice. RESULTS: The aqueous dispersion of PEG-PLGA-PEG flows freely at room temperature but form a gel at 37 degrees C body temperature. The in vitro degradation of PEG-PLGA-PEG lasted for more than 30 days. The cytotoxicity of PEG-PLGA-PEG evaluated in HEK 293 cells was significantly lower than that of poly-L-lysine hydrochloride. The release profile of supercoiled pDNA from the polymer followed the zero-order kinetics up to 12 days. Maximal gene expression of luciferase was at 24 h in the skin wound of CD-1 mice and by 72 h, the expression dropped by nearly 94%. CONCLUSION: These results suggest hydrogel formed by PEG-PLGA-PEG could be a promising platform for delivery of pDNA, which represents a novel strategy that may serve as a non-viral vector for gene therapy in wound healing.

Intradermal injection of transforming growth factor-beta1 gene enhances wound healing in genetically diabetic mice.

PURPOSE: To evaluate the biologic effect of direct cutaneous TGF-beta1 gene delivery on impaired wound healing models using genetically diabetic mice. METHODS: Diabetic mice (C57BKS.Cg-m +/+ Leprdb female mice) with 1 cm x 1 cm excisional wounds were intradermally injected with 60 microg of plasmid DNA encoding TGF-beta1 gene. The wound closure was measured up to 14 days postwounding. At days 7 and 14 postwounding, sections of skin were taken for hematoxylin and eosin and Masson's trichome staining to examine the morphology and collagen deposition. The cell proliferation and TGF-beta1 gene expression were studied using immunohistochemical stainings for 5-bromo-2-deoxyuridine and for TGF-beta1. RESULTS: A higher cell proliferation rate and a denser and more organized new extracellular matrix were observed in the treated wound site. Complete wound closure was detected as early as 7 days for TGF-beta1-treated group in comparison with 11-14 days for the untreated, control plasmid DNA- and PBS-treated groups. CONCLUSION: A single intradermal injection of TGF-beta1 plasmid DNA was sufficient to enhance wound healing. This approach represents a new strategy that may be applied to the treatment of excisional wounds in human diabetic patients.

Thermosensitive hydrogel as a Tgf-beta1 gene delivery vehicle enhances diabetic wound healing.

PURPOSE: To accelerate diabetic wound healing with TGF-beta1 gene delivery system using a thermosensitive hydrogel made of a triblock copolymer, PEG-PLGA-PEG. METHODS: Two 7 x 7 mm full thickness excisional wounds were created in parallel at the back of each genetically diabetic mouse. The hydrogel containing plasmid TGF-beta1 was administered to the wound and formed an adhesive film in situ. Controls were either untreated or treated with the hydrogel without DNA. We used a commercial wound dressing, Humatrix, either with or without DNA, to compare the therapeutic effect with the thermosensitive hydrogel. RESULTS: We found that thermosensitive hydrogel alone is slightly beneficial for reepithealization at early stage of healing (day 1-5), but significantly accelerated repithelializaion, increased cell proliferation, and organized collagen were observed in the wound bed treated with thermosensitive hydrogel containing plasmid TGF-beta1. The accelerated reepithelialization was accompanied with enhanced collagen synthesis and more organized extracellular matrix deposition. Humatrix alone or with plasmid TGF-beta1, had little effect. CONCLUSIONS: Thermosensitive hydrogel made of PEG-PLGA-PEG triblock copolymer provides excellent wound dressing activity and delivers plasmid TGF-beta1 to promote wound healing in a diabetic mouse model.