Glioblastoma Multiforme (GBM) is one of the most aggressive forms of all cancers. The median survival with current standard-of-care radiation and chemotherapy is about 14months. GBM is difficult to ...treat due to heterogeneity in cancer cell population. MicroRNA-based drugs have rapidly become a vast and burgeoning field due to the ability of a microRNA (miRNA) to target many genes involved in key cellular pathways. However, in vivo delivery of miRNA remains a crucial challenge for its therapeutic success. To bypass this shortcoming, we designed polymeric nanogels (NGs), which are based on a polyglycerol-scaffold, as a new strategy of miRNA delivery for GBM therapy. We focused on miR-34a, which is known for its key role in important oncogenic pathways and its tumor suppression ability in GBM and other cancers. We evaluated the capability of six NG derivatives to complex with miR-34a, neutralize its negative charge and deliver active miRNA to the cell cytoplasm. Human U-87 MG GBM cells treated with our NG-miR-34a nano-polyplexes showed remarkable downregulation of miR-34a target genes, which play key roles in the regulation of apoptosis and cell cycle arrest, and induce inhibition of cells proliferation and migration. Administration of NG-miR-34a nano-polyplexes to human U-87 MG GBM-bearing SCID mice significantly inhibited tumor growth as opposed to treatment with NG-negative control miR polyplex or saline. The comparison between different polyplexes highlighted the key features for the rational design of polymeric delivery systems for oligonucleotides. Taken together, we expect that this new therapeutic approach will pave the way for safe and efficient therapies for GBM.
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The heterogeneity of pancreatic ductal adenocarcinoma (PDAC) suggests that successful treatment might rely on simultaneous targeting of multiple genes, which can be achieved by RNA interference-based ...therapeutic strategies. Here we show a potent combination of microRNA and siRNA delivered by an efficient nanocarrier to PDAC tumors. Using proteomic-microRNA profiles and survival data of PDAC patients from TCGA, we found a novel signature for prolonged survival. Accordingly, we used a microRNA-mimic to increase miR-34a together with siRNA to silence PLK1 oncogene. For in vivo dual-targeting of this combination, we developed a biodegradable amphiphilic polyglutamate amine polymeric nanocarrier (APA). APA-miRNA-siRNA polyplexes systemically administered to orthotopically inoculated PDAC-bearing mice showed no toxicity and accumulated at the tumor, resulting in an enhanced antitumor effect due to inhibition of MYC oncogene, a common target of both miR-34a and PLK1. Taken together, our findings warrant this unique combined polyplex's potential as a novel nanotherapeutic for PDAC.
Glioblastoma is a highly aggressive brain tumor. Current standard-of-care results in a marginal therapeutic outcome, partly due to acquirement of resistance and insufficient blood-brain barrier (BBB) ...penetration of chemotherapeutics. To circumvent these limitations, we conjugated the chemotherapy paclitaxel (PTX) to a dendritic polyglycerol sulfate (dPGS) nanocarrier. dPGS is able to cross the BBB, bind to P/L-selectins and accumulate selectively in intracranial tumors. We show that dPGS has dual targeting properties, as we found that P-selectin is not only expressed on tumor endothelium but also on glioblastoma cells. We delivered dPGS-PTX in combination with a peptidomimetic of the anti-angiogenic protein thrombospondin-1 (TSP-1 PM). This combination resulted in a remarkable synergistic anticancer effect on intracranial human and murine glioblastoma via induction of Fas and Fas-L, with no side effects compared to free PTX or temozolomide. This study shows that our unique therapeutic approach offers a viable alternative for the treatment of glioblastoma.
To date, several types of airway stents are available to treat central airway obstructions. However, the ideal stent that can overcome anatomical, mechanical and microbiological issues is still ...awaited. In addition, therapeutic effect and self-elimination of these stents are desirable properties, which pose an additional challenge for development and manufacturing. We aimed to create a prototype bioresorbable tracheal stent with acceptable clinical tolerance, fit and biocompatibility, that could be tested in a rabbit model and in the future be further optimized to enable drug-elution and ensure local therapeutic effect. Twenty-one New Zealand White Rabbits received five different types of bioresorbable tracheal stents, 3D-printed from poly(D,L-lactide-co-epsilon-caprolactone) metacrylates. Various configurations were tested for their functionality and improved until the best performing prototype could undergo detailed in vivo assessment, regarding clinical tolerance, migration and biocompatibility. Previously tested types of 3D printed stents in our preliminary study required improvement due to several problems, mainly related to breakage, unreliable stability and/or migration within the trachea. Abandoned or refined pre-prototypes were not analyzed in a comparative way. The final best performing prototype stent (GSP2 (Group Stent Prototype 2), n = 8) allowed a transoral application mode and showed good clinical tolerance, minimal migration and acceptable biocompatibility. The good performance of stent type GSP2 was attributed to the helix-shaped surface structure, which was therefore regarded as a key-feature. This prototype stent offers the possibility for further research in a large animal model to confirm the promising data and assess other properties such as bioresorption.
The presence of dormant, microscopic cancerous lesions poses a major obstacle for the treatment of metastatic and recurrent cancers. While it is well-established that microRNAs play a major role in ...tumorigenesis, their involvement in tumor dormancy has yet to be fully elucidated. We established and comprehensively characterized pairs of dormant and fast-growing human osteosarcoma models. Using these pairs of mouse tumor models, we identified three novel regulators of osteosarcoma dormancy: miR-34a, miR-93, and miR-200c. This report shows that loss of these microRNAs occurs during the switch from dormant avascular into fast-growing angiogenic phenotype. We validated their downregulation in patients’ tumor samples compared to normal bone, making them attractive candidates for osteosarcoma therapy. Successful delivery of miRNAs is a challenge; hence, we synthesized an aminated polyglycerol dendritic nanocarrier, dPG-NH2, and designed dPG-NH2-microRNA polyplexes to target cancer. Reconstitution of these microRNAs using dPG-NH2 polyplexes into Saos-2 and MG-63 cells, which generate fast-growing osteosarcomas, reduced the levels of their target genes, MET proto-oncogene, hypoxia-inducible factor 1α, and moesin, critical to cancer angiogenesis and cancer cells’ migration. We further demonstrate that these microRNAs attenuate the angiogenic capabilities of fast-growing osteosarcomas in vitro and in vivo. Treatment with each of these microRNAs using dPG-NH2 significantly prolonged the dormancy period of fast-growing osteosarcomas in vivo. Taken together, these findings suggest that nanocarrier-mediated delivery of microRNAs involved in osteosarcoma tumor–host interactions can induce a dormant-like state.
Development of chemo-resistance is a major challenge in glioblastoma (GB) treatment. This phenomenon is often driven by increased activation of genes associated with DNA repair, such as the ...alkyl-removing enzyme O
-methylguanine-DNA methyltransferase (MGMT) in combination with overexpression of canonical genes related to cell proliferation and tumor progression, such as Polo-like kinase 1 (Plk1). Hereby, we attempt to sensitize resistant GB cells using our established amphiphilic poly(α)glutamate (APA): small interfering RNA (siRNA) polyplexes, targeting Plk1. Furthermore, we improved brain-targeting by decorating our nanocarrier with sulfonate groups. Our sulfonated nanocarrier showed superior selectivity towards P-selectin (SELP), a transmembrane glycoprotein overexpressed in GB and angiogenic brain endothelial cells. Self-assembled polyplexes of sulfonated APA and siPlk1 internalized into GB cells and into our unique 3-dimensional (3D) GB spheroids inducing specific gene silencing. Moreover, our RNAi nanotherapy efficiently reduced the cell viability of both chemo-sensitive and chemo-resistant GB cells. Our developed sulfonated amphiphilic poly(α)glutamate nanocarrier has the potential to target siRNA to GB brain tumors. Our findings may strengthen the therapeutic applications of siRNA for chemo-resistant GB tumors, or as a combination therapy for chemo-sensitive GB tumors.
Abstract
Digital light processing (DLP) of structurally complex poly(ethylene glycol) (PEG) hydrogels with high mechanical toughness represents a long‐standing challenge in the field of 3D printing. ...Here, we report a 3D printing approach for the high‐resolution manufacturing of structurally complex and mechanically strong PEG hydrogels via heat‐assisted DLP. Instead of using aqueous solutions of photo‐crosslinkable monomers, PEG macromonomer melts were first printed in the absence of water, resulting in bulk PEG networks. Then, post‐printing swelling of the printed networks was achieved in water, producing high‐fidelity 3D hydrogels with complex structures. By employing a dual‐macromonomer resin containing a PEG‐based four‐arm macrophotoinitiator, “all‐PEG” hydrogel constructs were produced with compressive toughness up to 1.3 MJ m
−3
. By this approach, porous 3D hydrogel scaffolds with trabecular‐like architecture were fabricated, and the scaffold surface supported cell attachment and the formation of a monolayer mimicking bone‐lining cells. This study highlights the promises of heat‐assisted DLP of PEG photopolymers for hydrogel fabrication, which may accelerate the development of 3D tissue‐like constructs for regenerative medicine.
RNA interference is one of the most promising fields in modern medicine to treat several diseases, ranging from cancer to cardiac diseases, passing through viral infections and metabolic pathologies. ...Since the discovery of the potential therapeutic properties of non-self oligonucleotides, it was clear that it is important to develop delivery systems that are able to increase plasma stability and bestow membrane-crossing abilities to the oligonucleotides in order to reach their cytoplasmic targets. Polymer therapeutics, among other systems, are widely investigated as delivery systems for therapeutic agents, such as oligonucleotides. Physico-chemical characterization of the supramolecular polyplexes obtained upon charge interaction or covalent conjugation between the polymeric carrier and the oligonucleotides is critical. Appropriate characterization is fundamental in order to predict and understand the in vivo silencing efficacy and to avoid undesired side effects and toxicity profile. Shedding light on the physico-chemical and in vitro requirements of a polyplex leads to an efficient in vivo delivery system for RNAi therapeutics. In this review, we will present the most common techniques for characterization of obtained polymer/oligonucleotide polyplexes and an up-to-date state of the art in vivo preclinical and clinical studies. This is the first review to deal with the difficulties in appropriate characterization of small interfering RNA (siRNA) or microRNA (miRNA) polyplexes and conjugates which limit the clinical translation of this promising technology.
Abstract The progress in medical research has led to the understanding that cancer is a large group of heterogeneous diseases, with high variability between and within individuals. This variability ...sprouted the ambitious goal to improve therapeutic outcomes, while minimizing drug adverse effects through stratification of patients by the differences in their disease markers, in a personalized manner, as opposed to the strategy of “one therapy fits all”. Nanotheranostics, composed of nanoparticles (NPs) carrying thera peutic and/or diag nostics probes, have the potential to revolutionize personalized medicine. There are different modalities to combine these two distinct fields into one system for a synergistic outcome. The addition of a nanocarrier to a theranostic system holds great promise. Nanocarriers possess high surface area, enabling sophisticated functionalization with imaging agents, thus gaining enhanced diagnostic ability in real-time. Yet, most of the FDA-approved theranostics approaches are based on small molecules. The theranostic approaches that are reviewed herein are paving the road towards personalized medicine through all stages of patient care: starting from screening and diagnostics, proceeding to treatment and ending with treatment follow-up. Our current review provides a broad background and highlights new insights for the rational design of theranostic nanosystems for desired therapeutic niches, while summoning the hurdles on their way to become first-line diagnostics and therapeutics for cancer patients.
The hallmarks of three-dimensional (3D) cancer model. The complexity of elements and their roles in tumor progression can be recapitulated in vitro in 3D models of cancer. The creation of 3D tumor ...cell cultures opens the possibility to study: (a) extracellular matrix (ECM) composition and the rheological properties of tumor tissues; (b) tumor cells and their microenvironment cellular functions and interactions, in (c) a vascularized- and size- controlled 3D-bioprinted tissue; (d) drug toxicity and efficacy of nanomedicines, including immunotherapies, which can be exploited for prediction of drug combinations. Created with BioRender.com
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•3D models may bridge the translational gap between 2D cultures and animal studies.•3D cancer models may alter the currently accepted ideal properties of nanomedicines.•3D models can predict nanomedicine efficacy facilitating personalized cancer therapy.
The complexity and diversity of the biochemical processes that occur during tumorigenesis and metastasis are frequently over-simplified in the traditional in vitro cell cultures. Two-dimensional cultures limit researchers’ experimental observations and frequently give rise to misleading and contradictory results. Therefore, in order to overcome the limitations of in vitro studies and bridge the translational gap to in vivo applications, 3D models of cancer were developed in the last decades. The three dimensions of the tumor, including its cellular and extracellular microenvironment, are recreated by combining co-cultures of cancer and stromal cells in 3D hydrogel-based growth factors-inclusive scaffolds. More complex 3D cultures, containing functional blood vasculature, can integrate in the system external stimuli (e.g. oxygen and nutrient deprivation, cytokines, growth factors) along with drugs, or other therapeutic compounds. In this scenario, cell signaling pathways, metastatic cascade steps, cell differentiation and self-renewal, tumor-microenvironment interactions, and precision and personalized medicine, are among the wide range of biological applications that can be studied. Here, we discuss a broad variety of strategies exploited by scientists to create in vitro 3D cancer models that resemble as much as possible the biology and patho-physiology of in vivo tumors and predict faithfully the treatment outcome.
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