Publications by authors named "Hasan Uludaǧ"

156 Publications

Investigation of water-insoluble hydrophobic polyethylenimines as RNAi vehicles in chronic myeloid leukemia therapy.

J Biomed Mater Res A 2021 May 8. Epub 2021 May 8.

Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.

The discovery of RNA interference (RNAi) more than two decades ago opened avenues for avant-garde cancer treatments that possess the ability to evade issues hampering current chemotherapeutic strategies, owing to its specific gene sequence-driven mechanism of action. A potent short interfering RNA (siRNA) delivery vehicle designed to overcome physiological barriers is imperative for successful RNAi therapy. For this purpose, this study explored the characteristics and therapeutic efficacy of low-molecular weight (MW) polyethylenimine (PEI) with high cholesterol substitution, yielding water-insoluble polymers, in chronic myeloid leukemia (CML) K562 cells. A strong impact of cholesterol grafting on the physicochemical attributes of the resultant polymers and their corresponding complexes with siRNA was observed, with the siRNA binding capacity of polymers increasing and complex dissociation sensitivity decreasing with increase in cholesterol content of the polymers. The modified polymer complexes were significantly smaller in size and possessed higher cationic charge compared to the parent polymer. The interaction with anionic heparan sulfate preoteoglycans present on the cell surface was significant in cellular uptake of the complexes. The therapeutic efficacy of siRNA/polymer complexes was reflected in their ability to effectively silence the reporter green fluorescent protein gene and endogenous CML oncogene BCR-ABL as well as significantly inhibit colony formation by K562 cells post BCR-ABL silencing. The results of this study demonstrated beneficial effects of high levels of hydrophobic substitution on low MW PEI on their functional performance bestowing them the potential to be potent RNAi agents for CML therapy.
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http://dx.doi.org/10.1002/jbm.a.37214DOI Listing
May 2021

An overview of the use of biomaterials, nanotechnology, and stem cells for detection and treatment of COVID-19: towards a framework to address future global pandemics.

Emergent Mater 2021 Jan 5:1-16. Epub 2021 Jan 5.

Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.

A novel SARS-like coronavirus (severe acute respiratory syndrome-related coronavirus-2, SARS-CoV-2) outbreak has recently become a worldwide pandemic. Researchers from various disciplinary backgrounds (social to natural science, health and medicine, etc.) have studied different aspects of the pandemic. The current situation has revealed how the ongoing development of nanotechnology and nanomedicine can accelerate the fight against the novel viruses. A comprehensive solution to this and future pandemic outbreaks includes preventing the spread of the virus through anti-viral personal protective equipment (PPE) and anti-viral surfaces, plus efforts to encourage behavior to minimize risks. Studies of previously introduced anti-viral biomaterials and their optimization to fight against SARS-CoV-2 is the foundation of most of the recent progress. The identification of non-symptomatic patients and symptomatic patients is vital. Reviewing published research highlights the pivotal roles of nanotechnology and biomaterials in the development and efficiency of detection techniques, e.g., by applying nanotechnology and nanomedicine as part of the road map in the treatment of coronavirus disease 2019 (COVID-19) patients. In this review, we discuss efforts to deploy nanotechnology, biomaterials, and stem cells in each step of the fight against SARS-CoV-2, which may provide a framework for future efforts in combating global pandemics.
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http://dx.doi.org/10.1007/s42247-020-00143-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7783485PMC
January 2021

Prospects for RNAi Therapy of COVID-19.

Front Bioeng Biotechnol 2020 30;8:916. Epub 2020 Jul 30.

College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.

COVID-19 caused by the SARS-CoV-2 virus is a fast emerging disease with deadly consequences. The pulmonary system and lungs in particular are most prone to damage caused by the SARS-CoV-2 infection, which leaves a destructive footprint in the lung tissue, making it incapable of conducting its respiratory functions and resulting in severe acute respiratory disease and loss of life. There were no drug treatments or vaccines approved for SARS-CoV-2 at the onset of pandemic, necessitating an urgent need to develop effective therapeutics. To this end, the innate RNA interference (RNAi) mechanism can be employed to develop front line therapies against the virus. This approach allows specific binding and silencing of therapeutic targets by using short interfering RNA (siRNA) and short hairpin RNA (shRNA) molecules. In this review, we lay out the prospect of the RNAi technology for combatting the COVID-19. We first summarize current understanding of SARS-CoV-2 virology and the host response to viral entry and duplication, with the purpose of revealing effective RNAi targets. We then summarize the past experience with nucleic acid silencers for SARS-CoV, the predecessor for current SARS-CoV-2. Efforts targeting specific protein-coding regions within the viral genome and intragenomic targets are summarized. Emphasizing non-viral delivery approaches, molecular underpinnings of design of RNAi agents are summarized with comparative analysis of various systems used in the past. Promising viral targets as well as host factors are summarized, and the possibility of modulating the immune system are presented for more effective therapies. We place special emphasis on the limitations of past studies to propel the field faster by focusing on most relevant models to translate the promising agents to a clinical setting. Given the urgency to address lung failure in COVID-19, we summarize the feasibility of delivering promising therapies by the inhalational route, with the expectation that this route will provide the most effective intervention to halt viral spread. We conclude with the authors' perspectives on the future of RNAi therapeutics for combatting SARS-CoV-2. Since time is of the essence, a strong perspective for the path to most effective therapeutic approaches are clearly articulated by the authors.
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http://dx.doi.org/10.3389/fbioe.2020.00916DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7409875PMC
July 2020

TRAIL therapy and prospective developments for cancer treatment.

J Control Release 2020 10 17;326:335-349. Epub 2020 Jul 17.

Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada; Department of Chemical & Material Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada; Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada. Electronic address:

Tumor Necrosis Factor (TNF) Related Apoptosis-Inducing Ligand (TRAIL), an immune cytokine of TNF-family, has received much attention in late 1990s as a potential cancer therapeutics due to its selective ability to induce apoptosis in cancer cells. TRAIL binds to cell surface death receptors, TRAIL-R1 (DR4) and TRAIL-R2 (DR5) and facilitates formation of death-inducing signaling complex (DISC), eventually activating the p53-independent apoptotic cascade. This unique mechanism makes the TRAIL a potential anticancer therapeutic especially for p53-mutated tumors. However, recombinant human TRAIL protein (rhTRAIL) and TRAIL-R agonist monoclonal antibodies (mAb) failed to exert robust anticancer activities due to inherent and/or acquired resistance, poor pharmacokinetics and weak potencies for apoptosis induction. To get TRAIL back on track as a cancer therapeutic, multiple strategies including protein modification, combinatorial approach and TRAIL gene therapy are being extensively explored. These strategies aim to enhance the half-life and bioavailability of TRAIL and synergize with TRAIL action ultimately sensitizing the resistant and non-responsive cells. We summarize emerging strategies for enhanced TRAIL therapy in this review and cover a wide range of recent technologies that will provide impetus to rejuvenate the TRAIL therapeutics in the clinical realm.
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http://dx.doi.org/10.1016/j.jconrel.2020.07.013DOI Listing
October 2020

Editorial: Enabling Biomaterials for New Biomedical Technologies and Clinical Therapies.

Front Bioeng Biotechnol 2020 5;8:559. Epub 2020 Jun 5.

Department of Biomedical Engineering, University of Connecticut Health Center, Farmington, CT, United States.

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http://dx.doi.org/10.3389/fbioe.2020.00559DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7289920PMC
June 2020

Enabling Combinatorial siRNA Delivery against Apoptosis-Related Proteins with Linoleic Acid and α-Linoleic Acid Substituted Low Molecular Weight Polyethylenimines.

Pharm Res 2020 Feb 3;37(3):46. Epub 2020 Feb 3.

Department of Chemical & Material Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.

Purpose: Short interfering RNA (siRNA) therapy promises a new era in treatment of breast cancers but effective delivery systems are needed for clinical use. Since silencing complementary targets may offer improved efficacy, this study was undertaken to identify non-viral carriers for combinatorial siRNA delivery for more effective therapy.

Methods: A library of lipid-substituted polymers from low molecular weight polyethyleneimine (PEI), linoleic acid (LA) and α-linoleic acid (αLA) with amide or thioester linkages was prepared and investigated for delivering Mcl-1, survivin and STAT5A siRNAs in breast cancer cells.

Results: The effective polymers formed 80-190 nm particles with similar zeta-potentials, but the serum stability was greater for complexes formed with amide-linked lipid conjugates. The LA and αLA substitutions, with the low molecular weight PEI (1.2 kDa and 2.0 kDa) were able to deliver siRNA effectively to cells and retarded the growth of breast cancer cells. The amide-linked lipid substituents showed higher cellular delivery of siRNA as compared to thioester linkages. Upon combinational delivery of siRNAs, growth of MCF-7 cells was inhibited to a greater extent with 2.0PEI-LA9 mediated delivery of Mcl-1 combined survivin siRNAs as compared to individual siRNAs. The qRT-PCR analysis confirmed the decrease in mRNA levels of target genes with specific siRNAs and 2.0PEI-LA9 was the most effective polymer for delivering siRNAs (either single or in combination).

Conclusions: This study yielded effective siRNA carriers for combinational delivery of siRNAs. Careful choice of siRNA combinations will be critical since targeting individual genes might alter the expression of other critical mediators.
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http://dx.doi.org/10.1007/s11095-020-2770-9DOI Listing
February 2020

Electrospun gelatin matrices with bioactive pDNA polyplexes.

Int J Biol Macromol 2020 Apr 25;149:296-308. Epub 2020 Jan 25.

Department of Chemical & Material Engineering, Faculty of Engineering, University of Alberta, 2-021 RTF Edmonton, Alberta, Canada. Electronic address:

Recent advances in electrospinning are yielding intricate scaffolds for use in regenerative medicine. To explore the possibility of creating bioactive scaffolds with functional gene expression systems, electrospun gelatin mats bearing plasmid DNA (pDNA) polyplexes are explored. The pDNA is first condensed with a lipid-modified polyethylenimine (PEI) to create polyplexes including a poly(aspartic acid) (pAsp) additive, and subsequently electrospun after mixing the polyplexes in gelatin solution. The pDNA polyplexes, 82 nm in size with ζ-potential of +20 mV, are uniformly entrapped in mats with fiber diameter ranging between ~150 and ~350 nm. The additive complexes with pAsp display a significantly higher transfection activity in solution, which was also retained after entrapment in electrospun mats, based on GFP expression to human myoblast (C2C12) and mouse osteoblast cells (MC3T3-E1). Electrospinning of gelatin with polyethylene glycol improves the transfection efficiency, due to increased pDNA entrapment (~71%). To further validate gene-activated mats, a pDNA encoding BMP-2 shows robust alkaline phosphatase (ALP) induction in C2C12 and MC3T3-E1 cells as a marker of osteogenic differentiation. We conclude that creating gelatin fiber mats with bioactive pDNA polyplexes was feasible and such mats could aid in regenerative repair of a wide range of tissues.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.01.252DOI Listing
April 2020

Membrane lipids destabilize short interfering ribonucleic acid (siRNA)/polyethylenimine nanoparticles.

Nanoscale 2020 Jan;12(2):1032-1045

Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada.

Cell entry of polymeric nanoparticles (NPs) bearing polynucleotides is an important stage for successful gene delivery. In this work, we addressed the influence of cell membrane lipids on the integrity and configurational changes of NPs composed of short interfering ribonucleic acid (siRNA) and polyethylenimine. We focused on NPs derived from two different PEIs, unmodified low molecular weight PEI and linoleic acid (LA)-substituted PEI, and their interactions with two membrane lipids (zwitterionic 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC) and anionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS)). Our experiments showed that POPS liposomes interacted strongly with both types of NPs, which caused partial dissociation of the NPs. POPC liposomes, however, did not induce any dissociation. Consistent with the experiments, steered molecular dynamics simulations showed a stronger interaction between the NPs and the POPS membrane than between the NPs and the POPC membrane. Lipid substitution on the PEIs enhanced the stability of the NPs during membrane crossing; lipid association between PEIs of the LA-bearing NPs as well as parallel orientation of the siRNAs provided protection against their dissociation (unlike NPs from native PEI). Our observations provide valuable insight into the integrity and structural changes of PEI/siRNA NPs during membrane crossing which will help in the design of more effective carriers for nucleic acid delivery.
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http://dx.doi.org/10.1039/c9nr08128cDOI Listing
January 2020

A systematic comparison of lipopolymers for siRNA delivery to multiple breast cancer cell lines: In vitro studies.

Acta Biomater 2020 01 21;102:351-366. Epub 2019 Nov 21.

Department of Chemical and Material Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada. Electronic address:

Small interfering RNA (siRNA) therapy is a promising approach for treatment of a wide range of cancers, including breast cancers that display variable phenotypic features. To explore the general utility of siRNA therapy to control aberrant expression of genes in breast cancer, we conducted a detailed analysis of siRNA delivery and silencing response in vitro in 6 separate breast cancer cell models (MDA-MB-231, MDA-MB-231-KRas-CRM, MCF-7, AU565, MDA-MB-435 and MDA-MB-468 cells). Using lipopolymers for siRNA complexation and delivery, we found a large variation in siRNA delivery efficiency depending on the specific lipopolymer used for siRNA complexation and delivery. Some lipopolymers were effective in all cell types used in this study, indicating the possibility of universal carriers for siRNA therapy. The delivery efficiency for effective lipopolymers was not correlated with dextran uptake in the cells tested, which indicated a receptor-mediated internalization for siRNA complexes with lipopolymers, unlike fluid-phase transfer associated with dextran uptake. Consistent with this, specific inhibitors involved in clathrin- and caveolin-mediated endocytosis significantly (>50%) reduced the internalization of siRNA complexes in all cell types. Using JAK2 and STAT3 silencing in MDA-MB-231 and MDA-MB-468 cells, a general correlation between the uptake and silencing efficiency at the mRNA level was evident, but it appeared that the choice of the target rather than the cell type was more critical for consistent silencing. We conclude that siRNA therapy with lipopolymers can be undertaken in multiple breast cancer cell phenotypes with similar efficiency, indicating the general applicability of non-viral RNAi in clinical management of molecularly heterogeneous breast cancers. STATEMENT OF SIGNIFICANCE: The manuscript investigated the efficacy of siRNA carriers across multiple breast cancer cell lines. The lipopolymeric carriers were capable of delivering effective dose of siRNA to a range of breast cancer cells. Despite some differences in uptake efficiency among cell types, the mechanism of delivery was similar, with CME and CvME significantly involved in the internalization of polyplexes, while fluid-phase endocytosis was not significant. Specific target silencing was correlated to delivery efficiency, but we did notice the presence of lipopolymers that achieved high silencing with minimal siRNA delivery. Silencing specific targets in different cell types were more uniformly achieved as compared to targeting different targets in the same cells. Our studies enhance the feasibility of delivering siRNA to different types of breast cancer cells.
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http://dx.doi.org/10.1016/j.actbio.2019.11.036DOI Listing
January 2020

Cholesterol grafted cationic lipopolymers: Potential siRNA carriers for selective chronic myeloid leukemia therapy.

J Biomed Mater Res A 2020 03 26;108(3):565-580. Epub 2019 Nov 26.

Department of Chemical & Material Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta, Canada.

Synthetic siRNA technology has emerged as a promising approach for molecular therapy of cancer but, despite its potential for post-transcriptional gene silencing, there is an urgent need to develop efficient delivery systems particularly for difficult-to-transfect, anchorage-independent cells. In this study, we designed highly hydrophobic cationic lipopolymers by grafting cholesterol (Chol) onto low-molecular weight (0.6, 1.2, and 2.0 kDa) polyethylenimines (PEIs) to enable specific siRNA therapy to chronic myeloid leukemia (CML) cells. The siRNA binding by PEI-Chol led to nano-sized (100-200 nm diameter) polyplexes with enhanced ζ-potential (+20 to +35 mV) and ability to protect the loaded siRNA completely in fresh serum. The siRNA delivery to CML (K562) cells was proportional to degree of substitution and, unexpectedly, inversely proportional to molecular size of the polymeric backbone. Chol grafting with as little as ~1.0 Chol/PEI on 0.6 and 1.2 kDa PEIs enabled silencing of the reporter Green Fluorescent Protein gene as well as the endogenous BCR-Abl oncogene in K562 cells. The PEI-Chol mediated delivery of siRNAs specific for BCR-Abl and KSP genes significantly arrested the growth the cells which was significantly reflected in colony formation potency of K562 cells. BCR-Able siRNA mediated therapeutic efficacy was also observed in significantly increased caspase activity and apoptosis of K562 cells. Thus, Chol-grafted low-molecular weight PEIs appear to be unique siRNA carriers to realize the molecular therapy in CML cells.
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http://dx.doi.org/10.1002/jbm.a.36837DOI Listing
March 2020

Breathing New Life into TRAIL for Breast Cancer Therapy: Co-Delivery of pTRAIL and Complementary siRNAs Using Lipopolymers.

Hum Gene Ther 2019 12 29;30(12):1531-1546. Epub 2019 Oct 29.

Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada.

Preclinical studies showed that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) therapy is safe and effective to combat cancers, but clinical outcomes have been less than optimal due to short half-life of TRAIL protein, insufficient induction of apoptosis, and TRAIL resistance displayed in many tumors. In this study, we explored co-delivery of a TRAIL expressing plasmid (pTRAIL) and complementary small interfering RNAs (siRNAs) (silencing [BCL2L12] and [SOD1]) to improve the response of breast cancer cells against TRAIL therapy. It is desirable to co-deliver the pDNA along with siRNA using a single delivery agent, but this is challenging given different structures of long/flexible pDNA and short/rigid siRNA. Toward this goal, we identified an aliphatic lipid-grafted low-molecular weight polyethylenimine (PEI) that accommodated both pDNA and siRNA in a single complex. The co-delivery of pTRAIL with BCL2L12- or SOD1-specific siRNAs resulted more significant cell death in different breast cancer cells compared with separate delivery without affecting nonmalignant cells viability. Ternary complexes of lipopolymer with pTRAIL and BCL2L12 siRNA significantly retarded the growth of breast cancer xenografts in mice. The enhanced anticancer activity was attributed to increased secretion of TRAIL and sensitization of breast cancer cells against TRAIL by the co-delivered siRNAs. The lipid-grafted PEIs capable of co-delivering multiple types of nucleic acids can serve as powerful carriers for more effective complementary therapeutics. Graphical Abstract [Figure: see text].
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http://dx.doi.org/10.1089/hum.2019.096DOI Listing
December 2019

siRNA-mediated BCR-ABL silencing in primary chronic myeloid leukemia cells using lipopolymers.

J Control Release 2019 09 17;310:141-154. Epub 2019 Aug 17.

Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, AB, Canada; Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, AB, Canada; Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, AB, Canada. Electronic address:

Despite development of effective tyrosine kinase inhibitors for treatment of chronic myeloid leukemia (CML), some patients do not effectively respond to the therapy and can display resistance in response to the drug therapy. To develop an alternative approach to CML therapy, we are exploring siRNA mediated silencing of the primary CML oncogene, BCR-ABL, by using non-viral (polymeric) delivery systems. In this study, a group of lipopolymers derived from low molecular PEIs substituted with linoleic acid (LA), α-linolenic acid (αLA) and cholesterol (Chol) was investigated for the first time for siRNA delivery to CML primary samples. The delivery efficiency in primary cells was equivalent to CML K562 cell line, and the lipopolymers gave effective internalization of siRNA depending on the nature of lipid substituent. The PEI-αLA (2.5 αLA/PEI), PEI-Chol (2.2 Chol/PEI), and PEI-LA (2.6 LA/PEI) lipopolymers used as BCR-ABL siRNA carriers (at 60 nM siRNA) reduced the BCR-ABL mRNA expression by 17% to 45%, and inhibited the formation of colonies by 24% to 41% in comparison with control siRNA in mononuclear cells. BCR-ABL siRNA treatment reduced the BCR-ABL mRNA expression by 50% in one of two CD34+ samples tested, and combination of BCR-ABL siRNA with imatinib (IM) treatment decreased the colony formation by 65% in one of two samples evaluated. The fact that no single polymer was universally effective in all patient samples may suggest patient-to-patient variability in terms of therapeutic responses to siRNA therapy. These results showed that a low dose of BCR-ABL siRNA could be used with lipopolymers to reduce BCR-ABL mRNA expression, CML cell survival and colony formation. This proof of principle study in CML primary cells can be applied to silencing of other therapeutic targets besides BCR-ABL and a study with larger patient samples is warranted for better identification of effective siRNA carriers.
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http://dx.doi.org/10.1016/j.jconrel.2019.08.018DOI Listing
September 2019

At the Intersection of Biomaterials and Gene Therapy: Progress in Non-viral Delivery of Nucleic Acids.

Front Bioeng Biotechnol 2019 4;7:131. Epub 2019 Jun 4.

Department of Chemical and Materinals Engineering, University of Alberta, Edmonton, AB, Canada.

Biomaterials play a critical role in technologies intended to deliver therapeutic agents in clinical settings. Recent explosion of our understanding of how cells utilize nucleic acids has garnered excitement to develop a range of older (e.g., antisense oligonucleotides, plasmid DNA and transposons) and emerging (e.g., short interfering RNA, messenger RNA and non-coding RNAs) nucleic acid agents for therapy of a wide range of diseases. This review will summarize biomaterials-centered advances to undertake effective utilization of nucleic acids for therapeutic purposes. We first review various types of nucleic acids and their unique abilities to deliver a range of clinical outcomes. Using recent advances in T-cell based therapy as a case in point, we summarize various possibilities for utilizing biomaterials to make an impact in this exciting therapeutic intervention technology, with the belief that this modality will serve as a therapeutic paradigm for other types of cellular therapies in the near future. We subsequently focus on contributions of biomaterials in emerging nucleic acid technologies, specifically focusing on the design of intelligent nanoparticles, deployment of mRNA as an alternative to plasmid DNA, long-acting (integrating) expression systems, and / expansion of engineered T-cells. We articulate the role of biomaterials in these emerging nucleic acid technologies in order to enhance the clinical impact of nucleic acids in the near future.
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http://dx.doi.org/10.3389/fbioe.2019.00131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6558074PMC
June 2019

Current outlook on drug resistance in chronic myeloid leukemia (CML) and potential therapeutic options.

Drug Discov Today 2019 07 15;24(7):1355-1369. Epub 2019 May 15.

Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada. Electronic address:

Chronic myeloid leukemia cells are armed with several resistance mechanisms that can make current drugs ineffective. A better understanding of resistance mechanisms is yielding new approaches to management of the disease. Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm the hallmark of which, the breakpoint cluster region-Abelson (BCR-ABL) oncogene, has been the target of tyrosine kinase inhibitors (TKIs), which have significantly improved the survival of patients with CML. However, because of an increase in TKI resistance, it is becoming imperative to identify resistance mechanisms so that drug therapies can be better prescribed and new agents developed. In this review, we discuss the various BCR-ABL-dependent and -independent mechanisms of resistance observed in CML, and the range of therapeutic solutions available to overcome such resistance and to ultimately improve the survival of patients with CML.
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http://dx.doi.org/10.1016/j.drudis.2019.05.007DOI Listing
July 2019

siRNA Library Screening to Identify Complementary Therapeutic Pairs in Triple-Negative Breast Cancer Cells.

Methods Mol Biol 2019 ;1974:1-19

Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.

The existence of tightly integrated cross talk through multiple signaling and effector pathways has been appreciated in malignant cells. The realization of the plasticity of such networks is stimulating the development of combinational therapy to overcome the limitations of one-dimensional therapies. Synergistic pairs of siRNAs or siRNA and drug combinations are the new frontiers in identifying effective therapeutic combinations. To elucidate effective combinations, we developed a versatile protocol to screen siRNA libraries in triple-negative breast cancer cell models. This protocol outlines the steps to identify synergistic combinations of siRNA-siRNA or siRNA-drug combinations using siRNA libraries via a robotic screen. By focusing on smaller functional siRNA libraries, we present methodologies to identify synergistic siRNA pairings against cancerous cell growth and molecular targets to augment the activity of pro-apoptotic TRAIL protein. Here, we summarize the critical steps to undertake such combinational target identification, emphasizing critical factors that affect the outcome of the screens. Our experience suggests that siRNA library screening is an efficient protocol to identify complementary therapeutic pairs of new or already-existing drugs. This protocol is simple, robust and can be completed within a 1-week working period.
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http://dx.doi.org/10.1007/978-1-4939-9220-1_1DOI Listing
November 2019

Advances in biology of acute lymphoblastic leukemia (ALL) and therapeutic implications.

Am J Blood Res 2018 10;8(4):29-56. Epub 2018 Dec 10.

Department of Medicine, University of Alberta Edmonton, Alberta, Canada.

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer and also occurs in adults. Although the outcomes of multi-agent chemotherapy regimens have greatly improved, high toxicity and relapses in many patients necessitate the development of novel therapeutic approaches. Advances in molecular profiling and cytogenetics have identified a broad range of genetic abnormalities, including gene mutations, chromosome translocations and aneuploidy, which has provided a more comprehensive understanding of the biology and pathogenesis of ALL. This understanding has also led to new targeted therapeutic approaches, including the use of selective small molecule inhibitors, nucleic acid-based therapies and immune-based therapies mediated by specific monoclonal antibodies and cellular immunotherapy, which are poised to revolutionize the treatment of various ALL subtypes. The main focus of this review is to highlight the latest advances in ALL biology, including the identification of prognostic factors and putative therapeutic targets. We also review the current status of, and ongoing progress in, the development of targeted therapies for ALL.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334189PMC
December 2018

Silencing by siRNA: A Potent Approach to Sensitize Chronic Myeloid Leukemia Cells to Tyrosine Kinase Inhibitor Therapy.

Stem Cells Dev 2019 06 22;28(11):734-744. Epub 2019 Jan 22.

1 Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Canada.

Nonviral gene therapy with specific short interfering RNAs (siRNAs) against can be an alternative and/or supportive therapy of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKIs), given the often observed resistance to TKIs in clinical setting. In this study, we explored the feasibility of BCR-Abl siRNA therapy in CML K562 cells in vitro by employing a cationic polymer derived from cholesterol (Chol) grafted low-molecular weight polyethyleneimine (PEI). The first generation TKI imatinib upregulated the expression of in K562 cells as expected. Delivery of BCR-Abl siRNA in both drug-sensitive and drug-resistant K562 cells significantly downregulated the mRNA levels in both cell types. Similarly, the siRNA treatment arrested the growth of both drug-sensitive and drug-resistant K562 cells with no obvious differences despite a large difference in drug responsiveness. The gene silencing in combination with TKI treatments exhibited significant synergism in drug-resistant K562 cells in generating substantial antileukemic activity, where the TKIs on their own were not effective. The effect of BCR-Abl siRNA and TKIs on non-CML cells (Jurkat and primary fibroblast) was negligible, indicating the specificity of the proposed therapy. This strategy can significantly overcome TKI resistance in CML cells, suggesting a feasible and effective treatment model for CML patients suffering from clinical resistances.
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http://dx.doi.org/10.1089/scd.2018.0196DOI Listing
June 2019

Current state of fabrication technologies and materials for bone tissue engineering.

Acta Biomater 2018 10 22;80:1-30. Epub 2018 Sep 22.

Department of Chemical & Materials Engineering, Faculty of Engineering, U. of Alberta, Edmonton, AB, Canada; Faculty of Pharmacy & Pharmaceutical Sciences, U. of Alberta, Edmonton, AB, Canada; Department of Biomedical Engineering, Faculty of Medicine & Dentistry, U. of Alberta, Edmonton, AB, Canada. Electronic address:

A range of traditional and free-form fabrication technologies have been investigated and, in numerous occasions, commercialized for use in the field of regenerative tissue engineering (TE). The demand for technologies capable of treating bone defects inherently difficult to repair has been on the rise. This quest, accompanied by the advent of functionally tailored, biocompatible, and biodegradable materials, has garnered an enormous research interest in bone TE. As a result, different materials and fabrication methods have been investigated towards this end, leading to a deeper understanding of the geometrical, mechanical and biological requirements associated with bone scaffolds. As our understanding of the scaffold requirements expands, so do the capability requirements of the fabrication processes. The goal of this review is to provide a broad examination of existing scaffold fabrication processes and highlight future trends in their development. To appreciate the clinical requirements of bone scaffolds, a brief review of the biological process by which bone regenerates itself is presented first. This is followed by a summary and comparisons of commonly used implant techniques to highlight the advantages of TE-based approaches over traditional grafting methods. A detailed discussion on the clinical and mechanical requirements of bone scaffolds then follows. The remainder of the manuscript is dedicated to current scaffold fabrication methods, their unique capabilities and perceived shortcomings. The range of biomaterials employed in each fabrication method is summarized. Selected traditional and non-traditional fabrication methods are discussed with a highlight on their future potential from the authors' perspective. This study is motivated by the rapidly growing demand for effective scaffold fabrication processes capable of economically producing constructs with intricate and precisely controlled internal and external architectures. STATEMENT OF SIGNIFICANCE: The manuscript summarizes the current state of fabrication technologies and materials used for creating scaffolds in bone tissue engineering applications. A comprehensive analysis of different fabrication methods (traditional and free-form) were summarized in this review paper, with emphasis on recent developments in the field. The fabrication techniques suitable for creating scaffolds for tissue engineering was particularly targeted and their use in bone tissue engineering were articulated. Along with the fabrication techniques, we emphasized the choice of materials in these processes. Considering the limitations of each process, we highlighted the materials and the material properties critical in that particular process and provided a brief rational for the choice of the materials. The functional performance for bone tissue engineering are summarized for different fabrication processes and the choice of biomaterials. Finally, we provide a perspective on the future of the field, highlighting the knowledge gaps and promising avenues in pursuit of effective scaffolds for bone tissue engineering. This extensive review of the field will provide research community with a reference source for current approaches to scaffold preparation. We hope to encourage the researchers to generate next generation biomaterials to be used in these fabrication processes. By providing both advantages and disadvantage of each fabrication method in detail, new fabrication techniques might be devised that will overcome the limitations of the current approaches. These studies should facilitate the efforts of researchers interested in generating ideal scaffolds, and should have applications beyond the repair of bone tissue.
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http://dx.doi.org/10.1016/j.actbio.2018.09.031DOI Listing
October 2018

Additive Polyplexes to Undertake siRNA Therapy against CDC20 and Survivin in Breast Cancer Cells.

Biomacromolecules 2018 11 2;19(11):4193-4206. Epub 2018 Oct 2.

Small interfering RNA (siRNA) delivered to silence overexpressed genes associated with malignancies is a promising targeted therapy to decrease the uncontrolled growth of malignant cells. To create potent delivery agents for siRNA, here we formulated additive polyplexes of siRNA using linoleic acid-substituted polyethylenimine and additive polymers (hyaluronic acid, poly(acrylic acid), dextran sulfate, and methyl cellulose) and characterized their physicochemical properties and effectiveness. Incorporating polyanionic polymer along with anionic siRNA in polyplexes was found to decrease the ζ-potential of polyplexes but enhance the cellular delivery of siRNA. The CDC20 and survivin siRNAs delivered by additive polyplexes showed promising efficacy in breast cancer MDA-MB-231, SUM149PT, MDA-MB-436, and MCF7 cells. However, the side effects of the siRNA delivery were observed in nonmalignant cells, and a careful formulation of siRNA/polymer polyplexes was needed to minimize side effects on normal cells. Because the efficacy of siRNA delivery by additive polyplexes was independent of breast cancer phenotypes used in this study, these polyplexes could be further developed to treat a wide range of breast cancers.
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http://dx.doi.org/10.1021/acs.biomac.8b00918DOI Listing
November 2018

Steered molecular dynamics simulations reveal a self-protecting configuration of nanoparticles during membrane penetration.

Nanoscale 2018 Sep;10(37):17671-17682

Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada.

Cell entry of polynucleotide-based therapeutic agents can be facilitated by nanoparticle (NP) mediated delivery. In this work, using steered molecular dynamics simulations, we simulated the membrane penetration process of a NP formed by 2 short interfering RNA (siRNA) and 6 polyethylenimine (PEI) molecules. To the best of our knowledge, this is the first set of simulations that explore the direct penetration of an siRNA/PEI NP through a membrane at an all-atom scale. Three types of PEI molecules were used for NP formation: a native PEI, a PEI modified with caprylic acids and a PEI modified with linoleic acids. We found that hydrogen bond formation between the PEIs and the membrane did not lead to instability of the siRNA/PEI NPs during the internalization process. Instead, our results suggested adoption of a "self-protecting" configuration by the siRNA/PEI NP during membrane penetration, where the siRNA/PEI NP becomes more compact and siRNAs become aligned, leading to more stable configurations while detaching from the membrane. The siRNA/PEI NP modified with linoleic acid showed the smallest structural change due to its strong intra-particle lipid associations and the resulting rigidity, while NP modified with caprylic acid showed the largest structural changes. Our observations provide unique insight into the structural changes of siRNA/PEI NPs when crossing the cell membrane, which can be important for the design of new NP carriers for nucleic acid delivery.
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http://dx.doi.org/10.1039/c8nr04287jDOI Listing
September 2018

Molecular Dynamics Simulations on Nucleic Acid Binding Polymers Designed To Arrest Thrombosis.

ACS Appl Mater Interfaces 2018 Aug 20;10(34):28399-28411. Epub 2018 Aug 20.

Department of Biomedical Engineering , University of Alberta , Edmonton , Alberta T6G 2V2 , Canada.

Cancer-associated thrombosis is managed by the administration of anticoagulants and antithrombotic agents that have a high risk of inducing hemorrhagic complications. To develop safer strategies for antithrombotic therapy, in vivo activators of the intrinsic pathway, namely, cell-free nucleic acids (DNA and RNA) have been targeted with cationic, polyamine-based polymers. The cytotoxicity of the highly cationic polymers is a major drawback for their practical use, and biocompatible alternatives are in high demand. In this study, we carried out all-atom molecular dynamics simulations to systematically examine the DNA binding of polyamine-poly(ethylene glycol) (PEG) diblock polymers designed from biocompatible building blocks to inhibit the procoagulant activity of DNA. The differences in cationic charge, PEG chain length, and initial conformations of the polymers resulted in marked differences in their binding to DNA. We found that having an exposed cationic polyamine group is essential to polymer-DNA binding and a certain level of electrostatic interactions is necessary to maintain the bound state. Intrachain associations between the polyamine groups and PEG chains in some cases have led to a collapsed state of the polymer that precludes binding to DNA. This self-association is mainly due to a strong hydrogen bond between polymer polyamine and PEG groups and partly due to a partially charged semibranched polyamine group architecture. As polymer "masking" of DNA is thought to arrest DNA's prothrombotic activity, our findings highlight the desired structural features of the polymers for stronger DNA binding and provide insights into the design of novel antithrombotic agents.
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http://dx.doi.org/10.1021/acsami.8b09914DOI Listing
August 2018

Reactive Oxygen Species Mediate Therapeutic Ultrasound-Induced, Mitogen-Activated Protein Kinase Activation in C28/I2 Chondrocytes.

Ultrasound Med Biol 2018 10 21;44(10):2105-2114. Epub 2018 Jul 21.

Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada.

Low-intensity pulsed ultrasound (LIPUS) has been used for the treatment of non-healing fractures because of its therapeutic properties of stimulating enhancing endochondral bone formation. However, its mechanism of action remains unclear. In this study, we hypothesized that LIPUS activates mitogen-activated protein kinases through generation of reactive oxygen species. C28/I2 cells were stimulated with LIPUS for 10 and 20 min, while the control group was treated using a sham LIPUS transducer. Through quantitative reverse transcription polymerase chain reaction and immunoblot analyses, we determined that LIPUS application increased reactive oxygen species generation and cell viability in C28/I2 cells. There were increases in the phosphorylation level of ERK1/2 and in expression of SOX9, COL2 A1 and ACAN genes. These effects were reversed when cells were treated with diphenylene iodonium, which is known to inhibit NADPH oxidase. It was concluded that exposure of chondrocytes to LIPUS led to reactive oxygen species generation, which activated MAPK signaling and further increased chondrocyte-specific gene markers involved in chondrocyte differentiation and extracellular matrix formation.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2018.05.025DOI Listing
October 2018

siRNA/lipopolymer nanoparticles to arrest growth of chronic myeloid leukemia cells in vitro and in vivo.

Eur J Pharm Biopharm 2018 Sep 18;130:66-70. Epub 2018 Jun 18.

Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, AB T6G 2V2, Canada; Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, AB T6G 1H9, Canada; Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, AB T6G 2H1, Canada. Electronic address:

Therapies for the treatment of Chronic Myeloid Leukemia and other leukemias are still limited for patients at advanced stages, which allow development of point mutations in the BCR-ABL fusion gene that render CML cells insensitive to therapies. An effective non-viral delivery system based on lipopolymers is described in this study to deliver specific siRNAs to CML cells for therapeutic gene silencing. The lipopolymer, based on the lipid α-linolenic acid (αLA) substitution on low molecular weight polyethyleneimine (PEI), was used to deliver siRNA against the BCR-ABL gene and, the resultant therapeutic effect was evaluated in in vitro and in vivo CML models. The study concluded that siRNA/PEI-αLA nanoparticles enabled silencing of the BCR-ABL gene and BCR-ABL protein, which consequently reduced growth on CML K562 cells in vitro and arrested the growth of localized tumors in a localized CML mouse model. The results from this study confirmed the potential use of lipopolymers as delivery systems and are encouraging for the future design of non-viral delivery systems for the treatment of CML and other hematological malignancies resulting from gene fusions.
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http://dx.doi.org/10.1016/j.ejpb.2018.06.018DOI Listing
September 2018

A review of nanostructured surfaces and materials for dental implants: surface coating, patterning and functionalization for improved performance.

Biomater Sci 2018 May;6(6):1312-1338

Department of Medical Nanotechnology, International Campus, Tehran University of Medical Sciences, Tehran, Iran.

The emerging field of nanostructured implants has enormous scope in the areas of medical science and dental implants. Surface nanofeatures provide significant potential solutions to medical problems by the introduction of better biomaterials, improved implant design, and surface engineering techniques such as coating, patterning, functionalization and molecular grafting at the nanoscale. This review is of an interdisciplinary nature, addressing the history and development of dental implants and the emerging area of nanotechnology in dental implants. After a brief introduction to nanotechnology in dental implants and the main classes of dental implants, an overview of different types of nanomaterials (i.e. metals, metal oxides, ceramics, polymers and hydrides) used in dental implant together with their unique properties, the influence of elemental compositions, and surface morphologies and possible applications are presented from a chemical point of view. In the core of this review, the dental implant materials, physical and chemical fabrication techniques and the role of nanotechnology in achieving ideal dental implants have been discussed. Finally, the critical parameters in dental implant design and available data on the current dental implant surfaces that use nanotopography in clinical dentistry have been discussed.
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http://dx.doi.org/10.1039/c8bm00021bDOI Listing
May 2018

Development of PEI-RANK siRNA Complex Loaded PLGA Nanocapsules for the Treatment of Osteoporosis.

Tissue Eng Part A 2019 01 30;25(1-2):34-43. Epub 2018 Apr 30.

1 BIOMATEN, Middle East Technical University (METU) Center of Excellence in Biomaterials and Tissue Engineering, Ankara, Turkey.

Osteoporosis, which is characterized by low bone mineral density and susceptibility to fracture, is caused by increased osteoclastic activity. Receptor activator of nuclear factor kappa B ligand (RANKL)/RANK signaling plays an important role in osteoclast differentiation and activation. The current treatment strategies for osteoporosis do not directly address this underlying cause and generates undesired side effects. This led to emergence of controlled delivery systems to increase drug bioavailability and efficacy specifically at the bone tissue. With better understanding of molecular pathology of bone, the use of small interfering RNA (siRNA) to inhibit translation of abnormal gene expression in cells is becoming a promising approach. In this study, we report a siRNA delivery system consisting of PEI:RANK siRNA complex entrapped in nanosized poly(lactic acid-co-glycolic acid) (PLGA) capsules intended to be used in the treatment of osteoporosis. The nanosize will enable the nanoparticles to be administered by intravenous injection. The RANK siRNA was complexed with polyethylenimine (PEI) and loaded into biodegradable PLGA nanocapsules (NCs). The PEI:RANK siRNA loaded nanocapsules significantly reduced (47%) RANK mRNA levels. The differentiation of osteoclast precursors to mature osteoclasts was significantly suppressed (∼54%). The reduction in the osteoclastic activity of the differentiated osteoclasts (55%) was found to be statistically significant. The siRNA delivery system developed in the study is planned to be tested i.v. in mouse and has the potential to be used as a novel alternative approach for the systemic treatment of osteoporosis.
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http://dx.doi.org/10.1089/ten.TEA.2017.0476DOI Listing
January 2019

Mechanistic insights into the role of glycosaminoglycans in delivery of polymeric nucleic acid nanoparticles by molecular dynamics simulations.

Biomaterials 2018 02 22;156:107-120. Epub 2017 Nov 22.

Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada. Electronic address:

Delivery of polynucleotide-based therapeutics into target cells involves interactions with glycosaminoglycan chains that are located on cell membrane milieu. Mechanisms governing glycosaminoglycan-mediated changes in the nanoparticulate structures of polymer-polynucleotide complexes are unknown, and cannot be fully elucidated without atomistic level details of molecular interactions. We selected a representative nanoparticulate system consisting of a short interfering RNA (siRNA)-polyethylenimine complex, and performed all-atom molecular dynamics simulations with the prototypical glycosaminoglycan heparin. We monitored the binding between the complex constituents and the heparin, and identified key features contributing to the response of the siRNA nanoparticles to heparin. We observed three main metastable states that the siRNA nanoparticles might visit in the presence of heparin, which can be translated into different functional outcomes. By correlating our data with the widely different and seemingly contradictory roles previously assigned to glycosaminoglycans, this study provides unique insights into the discrepancies in the experimental literature concerning the role of glycosaminoglycans in the polymeric nanoparticle delivery.
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http://dx.doi.org/10.1016/j.biomaterials.2017.11.037DOI Listing
February 2018

Combinational siRNA delivery using hyaluronic acid modified amphiphilic polyplexes against cell cycle and phosphatase proteins to inhibit growth and migration of triple-negative breast cancer cells.

Acta Biomater 2018 01 26;66:294-309. Epub 2017 Nov 26.

Faculty of Pharmacy & Pharmaceutical Sciences, U. of Alberta, Edmonton, AB, Canada; Department of Chemical & Materials Engineering, Faculty of Engineering, U. of Alberta, Edmonton, AB, Canada; Department of Biomedical Engineering, Faculty of Medicine & Dentistry, U. of Alberta, Edmonton, AB, Canada. Electronic address:

Triple-negative breast cancer is an aggressive form of breast cancer with few therapeutic options if it recurs after adjuvant chemotherapy. RNA interference could be an alternative therapy for metastatic breast cancer, where small interfering RNA (siRNA) can silence the expression of aberrant genes critical for growth and migration of malignant cells. Here, we formulated a siRNA delivery system using lipid-substituted polyethylenimine (PEI) and hyaluronic acid (HA), and characterized the size, ζ-potential and cellular uptake of the nanoparticulate delivery system. Higher cellular uptake of siRNA by the tailored PEI/HA formulation suggested better interaction of complexes with breast cancer cells due to improved physicochemical characteristics of carrier and HA-binding CD44 receptors. The siRNAs against specific phosphatases that inhibited migration of MDA-MB-231 cells were then identified using library screen against 267 protein-tyrosine phosphatases, and siRNAs to inhibit cell migration were further validated. We then assessed the combinational delivery of a siRNA against CDC20 to decrease cell growth and a siRNA against several phosphatases shown to decrease migration of breast cancer cells. Combinational siRNA therapy against CDC20 and identified phosphatases PPP1R7, PTPN1, PTPN22, LHPP, PPP1R12A and DUPD1 successfully inhibited cell growth and migration, respectively, without interfering the functional effect of the co-delivered siRNA. The identified phosphatases could serve as potential targets to inhibit migration of highly aggressive metastatic breast cancer cells. Combinational siRNA delivery against cell cycle and phosphatases could be a promising strategy to inhibit both growth and migration of metastatic breast cancer cells, and potentially other types of metastatic cancer.

Statement Of Significance: The manuscript investigated the efficacy of a tailored polymeric siRNA delivery system formulation as well as combinational siRNA therapy in metastatic breast cancer cells to inhibit malignant cell growth and migration. The siRNA delivery was undertaken by non-viral means with PEI/HA. We identified six phosphatases that could be critical targets to inhibit migration of highly aggressive metastatic breast cancer cells. We further report on specifically targeting cell cycle and phosphatase proteins to decrease both malignant cell growth and migration simultaneously. Clinical gene therapy against metastatic breast cancer with effective and safe delivery systems is urgently needed to realize the potential of molecular medicine in this deadly disease and our studies in this manuscript is intended to facilitate this endeavor.
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http://dx.doi.org/10.1016/j.actbio.2017.11.036DOI Listing
January 2018

Novel targets for sensitizing breast cancer cells to TRAIL-induced apoptosis with siRNA delivery.

Int J Cancer 2018 02 16;142(3):597-606. Epub 2017 Oct 16.

Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in variety of cancer cells without affecting most normal cells, which makes it a promising agent for cancer therapy. However, TRAIL therapy is clinically not effective due to resistance induction. To identify novel regulators of TRAIL that can aid in therapy, protein targets whose silencing sensitized breast cancer cells against TRAIL were screened with an siRNA library against 446 human apoptosis-related proteins in MDA-231 cells. Using a cationic lipopolymer (PEI-αLA) for delivery of library members, 16 siRNAs were identified that sensitized the TRAIL-induced death in MDA-231 cells. The siRNAs targeting BCL2L12 and SOD1 were further evaluated based on the novelty and their ability to sensitize TRAIL induced cell death. Silencing both targets sensitized TRAIL-mediated cell death in MDA-231 cells as well as TRAIL resistant breast cancer cells, MCF-7. Combination of TRAIL and siRNA silencing BCL2L12 had no effect in normal human umbilical vein cells and human bone marrow stromal cell. The silencing of BCL2L12 and SOD1 enhanced TRAIL-mediated apoptosis in MDA-231 cells via synergistically activating capsase-3 activity. Hence, here we report siRNAs targeting BCL2L12 and SOD1 as a novel regulator of TRAIL-induced cell death in breast cancer cells, providing a new approach for enhancing TRAIL therapy for breast cancer. The combination of siRNA targeting BCL2L12 and TRAIL can be a highly effective synergistic pair in breast cancer cells with minimal effect on the non-transformed cells.
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http://dx.doi.org/10.1002/ijc.31079DOI Listing
February 2018

Biomaterials for polynucleotide delivery to anchorage-independent cells.

J Mater Chem B 2017 Sep 29;5(35):7238-7261. Epub 2017 Aug 29.

Department of Chemical & Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada.

Anchorage-independent cells possess morphological features and cell membrane compositions that are distinct from adherent cells. They display minimal surface area, have a low rate of endocytosis and generally possess few proteoglycans which make it a challenge to deliver nucleic acids into them. Wide ranges of methods and materials have been developed to tackle the delivery obstacles for the polynucleotide-based therapeutics in modifying non-adherent cells. This article summarizes the techniques and biomaterials that have been utilized for transfection of anchorage-independent cells. First, physical techniques are briefly described along with particular applications for which they are well-suited. The structure-activity relationship of various biomaterial carriers of polynucleotides are then discussed with strategies employed to enhance their capability to transfect anchorage-independent cells. In conclusion, the authors' perspectives on different methods for polynucleotide delivery to primary human cells are compared, along with a discussion of their progression towards clinical trials.
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http://dx.doi.org/10.1039/c7tb01833aDOI Listing
September 2017

Role of Reactive Oxygen Species during Low-Intensity Pulsed Ultrasound Application in MC-3 T3 E1 Pre-osteoblast Cell Culture.

Ultrasound Med Biol 2017 11 12;43(11):2699-2712. Epub 2017 Aug 12.

Department of Dentistry, Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.

We evaluated the activation of mitogen-activated protein kinase (MAPK) activation through reactive oxygen species (ROS) by application of low-intensity ultrasound (LIPUS) to MC-3 T3 E1 pre-osteoblasts. The cells were subjected to one LIPUS application for either 10 or 20 min, and the control group was exposed to a sham transducer. For ROS inhibition, 10 μM diphenylene iodonium (DPI) was added to the cells an hour before LIPUS application. Samples were collected 1, 3, 6, 12 and 24 h after LIPUS application, and cells were evaluated for ROS generation, cell viability, gene expression and MAPK activation by immunoblot analyses. LIPUS caused a significant increase in ROS and cell viability in the non-DPI-treated group. Expression of RUNX2, OCN and OPN mRNA was higher in the LIPUS-treated groups at 1 h in both the DPI-treated and non-DPI-treated groups; RUNX2 and OCN mRNA levels increased at 6 h. ERK1/2 activation was increased in the LIPUS-treated groups. These results indicate that LIPUS activates MAPK by ROS generation in MC-3 T3 E1 pre-osteoblasts.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2017.07.002DOI Listing
November 2017