Production of Janus/Hecate microfibers by microfluidic photopolymerization and evaluation of their potential in dye removal.

The microfluidic production of Janus/Hecate polymer microfibers with well-defined interfaces from miscible phases is reported. The process offers tunability of the width and composition of each part of the fibers by controlling the flow rate and nature of the monomers in a single step. The enhanced performances of the fibers are outlined for the simultaneous removal of dyes of opposite charges using amphoteric Janus fibers.

Reengineering Tumor Microenvironment with Sequential Interleukin Delivery.

Some cytokines can reengineer anti-tumor immunity to modify the tumor micro-environment. Interleukin-27 (IL-27) can partially reduce tumor growth in several animal models, including prostate cancer. We hypothesized that addition of IL-18, which can induce the proliferation of several immune effector cells through inducing IFNγ could synergize with IL-27 to enhance tumor growth control. We describe our findings on the effects of IL-27 gene delivery on prostate cancer cells and how sequential therapy with IL-18 enhanced the efficacy of IL-27. The combination of IL-27 followed by IL-18 (27→18) successfully reduced cancer cell viability, with significant effects in cell culture and in an immunocompetent mouse model. We also examined a novel chimeric cytokine, comprising an IL-27 targeted at the C-terminus with a short peptide, LSLITRL (27pepL). This novel cytokine targets a receptor upregulated in tumor cells (IL-6Rα) via the pepL ligand. Interestingly, when we compared the 27→18 combination with the single 27pepL therapy, we observed a similar efficacy for both. This efficacy was further enhanced when 27pepL was sequenced with IL-18 (27pepL→18). The observed reduction in tumor growth and significantly enriched canonical pathways and upstream regulators, as well as specific immune effector signatures (as determined by bioinformatics analyses in the tumor microenvironment) supported the therapeutic design, whereby IL-27 or 27pepL can be more effective when delivered with IL-18. This cytokine sequencing approach allows flexible incorporation of both gene delivery and recombinant cytokines as tools to augment IL-27's bioactivity and reengineer efficacy against prostate tumors and may prove applicable in other therapeutic settings.

Production of lipophilic nanogels by spontaneous emulsification.

Nanosized gel particles, so-called nanogels, have attracted substantial interest in different application fields, thanks to their controllable and three-dimensional physical structure, good mechanical properties and potential biocompatibility. Literature reports many technologies for their preparation and design, however a recurrent limitation remains in their broad size distributions as well as in the poor size control. Therefore, the monodisperse and size-controlled nanogels preparation by simple process -like emulsification- is a real challenge still in abeyance to date. In this study we propose an original low energy emulsification approach for the production of monodisperse nanogels, for which the size can be finely controlled in the range 30 to 200 nm. The principle lies in the fabrication of a direct nano-emulsion containing both oil (medium chain triglycerides) and a bi-functional acrylate monomer. The nanogels are thus formed in situ upon UV irradiation of the droplet suspension. Advantage of such modification of the oil nano-carriers are the potential modulation of the release of encapsulated drugs, as a function of the density and/or properties of the polymer chain network entrapped in the oil nano-droplets. This hypothesis was confirmed using a model of hydrophobic drug -ketoprofen- entrapped into the nanogels particles, along with the study of the release profile, carried out in function of the nature of the monomers, density of polymer chains, and different formulation parameters.

Ligand-Mediated Targeting of Cytokine Interleukin-27 Enhances Its Bioactivity In Vivo.

We have examined the role of a novel targeted cytokine, interleukin-27 (IL-27), modified at the C terminus with a dual targeting and therapeutic heptapeptide, in treating prostate cancer. IL-27 has shown promise in halting tumor growth and mediating tumor regression in several cancer models, including prostate cancer. We describe our findings on the effects of targeted IL-27 gene delivery on prostate cancer cells in vitro and in vivo and how the targeting enhances bioactivity of the IL-27 cytokine. We applied the IL-27 gene delivery protocol utilizing sonoporation (sonodelivery) with the goal of reducing prostate tumor growth in an immunocompetent TC2R C57/BL6 model. The reduction in tumor growth and effector cellular profiles implicate targeted IL-27 as more effective than an untargeted version of IL-27 in promoting bioactivity, as assessed by STAT1 and IFN-γ reporter genes. Moreover, enhanced antitumor effects and significantly higher accumulation of natural killer T (NKT) and CD8 effector cells in the tumors were observed. These results support a novel IL-27-based targeting strategy that is promising since it shows improved therapeutic efficacy while utilizing simple and effective sonodelivery methods.

Synthesis and functionalization of hyperbranched polymers for targeted drug delivery.

Hyperbranched polymers (HBPs) have found use in a wide range of applications, such as optical, electronic and magnetic materials, coatings, additives, supramolecular chemistry, and biomedicine. HBPs have gained attention for the development of drug delivery systems due to the presence of internal cavities in their three-dimensional globular structure that can be used to encapsulate drugs and their facile synthesis as compared to dendrimers. The composition, topology, and functionality of HBPs have been tuned to design drug carriers with better efficacies. Recent advances have been reported to introduce functional groups to enhance targeting tumor cells. HBPs have been modified to promote passive and active targeting. This review article will describe the different routes to synthesize hyperbranched polymer, their use as drug carriers for targeted drug delivery, and their functionalization with ligands for active targeting through various synthesis strategies to give the reader an extended overview of the progresses accomplished in this field. The modification of HBPs with ligands such as peptides, oligonucleotides, and folic acid have been demonstrated to enhance the accumulation of the drug selectively at the tumor sites. The potential uses and developments of HBPs as nanoobjects for theranostics for example are discussed as perspectives.

Synthesis of Macromolecules Containing Phenylalanine and Aliphatic Building Blocks.

Aiming at developing efficient interfacial agents for fiber-reinforced composite materials, macromolecules are designed to have different components able to stick to the fiber and be compatible with the polymer matrix, respectively. Herein, macromolecules are prepared by solid-phase synthesis considering phenylalanine residues to promote adsorption of the macromolecule on aramid fibers and aliphatic building blocks to interact with a hydrophobic polymer matrix. Using phenylalanine as building block for the preparation of macromolecules by iterative synthesis has been shown to be challenging. Thus, the screening of various parameters for the optimization of the synthesis of these macromolecules is discussed in this communication. A preliminary thermal study by thermal gravimetric analysis is conducted to evaluate their thermal stability.

Orthogonal Synthesis of Xeno Nucleic Acids.

Sequence-defined peptide triazole nucleic acids (PTzNA) were synthesized by means of a solid-phase orthogonal "AB+CD" iterative strategy. In this approach, AB and CD building blocks containing carboxylic acid (A), azide (B), alkyne (C), and primary amine (D) functions are assembled together by successive copper-catalyzed azide-alkyne cycloaddition (CuAAC) and acid-amine coupling steps. Different PTzNA genetic sequences were prepared using a library of eight building blocks (i.e., four AB and four CD building blocks).

Dispersing Zwitterions into Comb Polymers for Nonviral Transfection: Experiments and Molecular Simulation.

Polymer-based gene delivery vehicles benefit from the presence of hydrophilic groups that mitigate the inherent toxicity of polycations and that provide tunable polymer-DNA binding strength and stable complexes (polyplexes). However, hydrophilic groups screen charge, and as such can reduce cell uptake and transfection efficiency. We report the effect of embedding zwitterionic sulfobetaine (SB) groups in cationic comb polymers, using a combination of experiments and molecular simulations. Ring-opening metathesis polymerization (ROMP) produced comb polymers with tetralysine (K4) and SB pendent groups. Dynamic light scattering, zeta potential measurements, and fluorescence-based experiments, together with coarse-grained molecular dynamics simulations, described the effect of SB groups on the size, shape, surface charge, composition, and DNA binding strength of polyplexes formed using these comb polymers. Experiments and simulations showed that increasing SB composition in the comb polymers decreased polymer-DNA binding strength, while simulations indicated that the SB groups distributed throughout the polyplex. This allows polyplexes to maintain a positive surface charge and provide high levels of gene expression in live cells. Notably, comb polymers with nearly 50 mol % SB form polyplexes that exhibit positive surface charge similarly as polyplexes formed from purely cationic comb polymers, indicating the ability to introduce an appreciable amount of SB functionality without screening surface charge. This integrated simulation-experimental study demonstrates the effectiveness of incorporating zwitterions in polyplexes, while guiding the design of new and effective gene delivery vectors.

Preparation of Information-Containing Macromolecules by Ligation of Dyad-Encoded Oligomers.

A simplified strategy for preparing non-natural information-containing polymers is reported. The concept relies on the successive ligation of oligomers that contain minimal sequence motifs. It was applied here to the synthesis of digitally-encoded poly(triazole amide)s, in which propyl and 2-methyl propyl motifs are used to code 0 and 1, respectively. A library of four oligo(triazole amide)s containing the information dyads 00, 01, 10, and 11 was prepared. These oligomers contain two reactive functions, that is, an alkyne and a carboxylic acid. Thus, they can be linked to another with the help of a reactive spacer containing azide and amine functions. Using two successive chemoselective steps, that is, azide-alkyne Huisgen cycloaddition and carboxylic acid-amine coupling, monodisperse polymers can be obtained. In particular, the library of dyads permits the implementation of any desired sequence using a small number of steps. As a proof-of-concept, the synthesis of molecular bytes 00000000 and 00000110 is described.

Sonodelivery Facilitates Sustained Luciferase Expression from an Episomal Vector in Skeletal Muscle.

Successful gene delivery to skeletal muscle is a desirable goal, not only for treating muscle diseases, but also for immunization, treatment of metabolic disorders, and/or delivering gene expression that can treat systemic conditions, such as bone metastatic cancer, for example. Although naked DNA uptake into skeletal muscle is possible, it is largely inefficient in the absence of additional chemical or physical delivery methods. We describe a system for delivery of non-viral or plasmid DNA to skeletal muscle using ultrasound-assisted sonoporation of a nanoplex combining plasmid DNA and a branched polymer based on poly(cyclooctene-graft-oligopeptide). The materials and methods described herein promise to advance the field of sonodelivery and of gene delivery to muscle for therapeutic applications since a simple system is presented that enables long-term gene expression in vivo with the promise of a minimal inflammatory gene expression profile.

Polymer-peptide delivery platforms: effect of oligopeptide orientation on polymer-based DNA delivery.

The success of nonviral transfection using polymers hinges on efficient nuclear uptake of nucleic acid cargo and overcoming intra- and extracellular barriers. By incorporating PKKKRKV heptapeptide pendent groups as nuclear localization signals (NLS) on a polymer backbone, we demonstrate protein expression levels higher than those obtained from JetPEI and Lipofectamine 2000, the latter being notorious for coupling high transfection efficiency with cytotoxicity. The orientation of the NLS peptide grafts markedly affected transfection performance. Polymers with the sequence attached to the backbone from the valine residue achieved a level of nuclear translocation higher than the levels of those having the NLS groups attached in the opposite orientation. The differences in nuclear localization and DNA complexation strength between the two orientations correlated with a striking difference in protein expression, both in cell culture and in vivo. Polyplexes formed from these comb polymer structures exhibited transfection efficiencies superior to those of Lipofectamine 2000 but with greatly reduced toxicity. Moreover, these novel polymers, when administered by intramuscular ultrasound-mediated delivery, allowed a high level of reporter gene expression in mice, demonstrating their therapeutic promise in vivo.

Synthesis of molecularly encoded oligomers using a chemoselective "AB + CD" iterative approach.

A library of eight sequence-defined model oligomers, whose sequence is based on a (0,1) binary code, is prepared through chemoselective repeating cycles of amidification and copper-assisted alkyne-azide cycloaddition reactions from a non-modified Wang resin. This library is constructed from two AB (A = acid, B = alkyne) building blocks, i.e., 4-pentynoic acid and 2-methyl-4-pentynoic acid acting, respectively, as non-coding (0) and coding (1) monomer, and 1-amino-11-azido-3,6,9-trioxaundecane as complementary CD (C = amine, D = azide) spacer building block. In particular, encoded triads are synthesized by consecutive covalent attachment of five building blocks (i.e., three coding/non-coding monomers and two spacers). In this communication, optimal protocols for the synthesis of the targeted oligomers are reported along with their full characterization by (1) H NMR, MALDI-TOF mass spectrometry, and size-exclusion chromatography. It is found that all possible encoded triads (i.e., eight possibilities) could be synthesized using this approach. Indeed, monodisperse sequence-defined oligomers are prepared and characterized in all cases.

Primary Structure Control of Oligomers Based on Natural and Synthetic Building Blocks.

Solid-phase synthesis was exploited for the preparation of oligomers constructed from natural and synthetic building blocks by combining the formation of amide bonds and copper-assisted alkyne-azide cycloaddition reactions extending the variety of oligomers with well-defined primary structures accessible through this technique and providing control over the spacing between amino acids.

Interleukin-27 gene delivery for modifying malignant interactions between prostate tumor and bone.

We have examined the role of a novel cytokine, interleukin-27 (IL-27), in mediating interactions between prostate cancer and bone. IL-27 is the most recently characterized member of the family of heterodimeric IL-12-related cytokines and has shown promise in halting tumor growth and mediating tumor regression in several cancer models, including prostate cancer. Prostate cancer is frequently associated with metastases to the bone, where the tumor induces a vicious cycle of communication with osteoblasts and osteoclasts to induce bone lesions, which are a significant cause of pain and skeletal-related events for patients, including a high fracture risk. We describe our findings in the effects of IL-27 gene delivery on prostate cancer cells, osteoblasts, and osteoclasts at different stages of differentiation. We applied the IL-27 gene delivery protocol in vivo utilizing sonoporation (sonodelivery) with the goal of treating and reducing the growth of prostate cancer at a bone metastatic site in vivo. We used a new model of immune-competent prostate adenocarcinoma and characterized the tumor growth reduction, gene expression, and effector cellular profiles. Our results suggest that IL-27 can be effective in reducing tumor growth, can help normalize bone structure, and can promote enhanced accumulation of effector cells in prostate tumors. These results are promising, because they are relevant to developing a novel IL-27-based strategy that can treat both the tumor and the bone, by using this simple and effective sonodelivery method for treating prostate tumor bone metastases.

Influence of Strong Electron-Donor Monomers in Sequence-Controlled Polymerizations.

A series of styrenic monomers containing strong donor substituents (i.e., 4-methylstyrene, 4-acetoxystyrene, and 4-tert-butoxystyrene) were tested in sequence-controlled radical copolymerizations in the presence of acceptor comonomers (i.e., N-substituted maleimide). The copolymers were synthesized by nitroxide-mediated polymerization using the commercially available alkoxyamine BlocBuilder MA. This technique allowed synthesis of copolymers with controlled molecular weights and molecular weight distributions for all monomers. Moreover, a beneficial effect of the donor substituents on the sequence-controlled copolymerization was noted. Indeed, all studied styrenic derivatives led to a very precise incorporation of functional N-substituted maleimides in the copolymer chains. The most favorable donor/acceptor copolymerization was observed with 4-tert-butoxystyrene. This particular monomer was therefore tested in the presence of various functional N-substituted maleimides (i.e., N-benzyl maleimide, 4-(N-maleimido) azobenzene), N-(1-pyrenyl)maleimide, and N-(2-(amino-Boc)ethylene)maleimide). In all cases, sequence-controlled microstructures were obtained and characterized. Moreover, the formed copolymers were hydrolyzed into poly(4-hydroxystyrene-co-N-substituted maleimide) derivatives. In all cases, it was verified that the sequence-controlled microstructure of the copolymers is preserved after hydrolysis.

Reconfiguring polylysine architectures for controlling polyplex binding and non-viral transfection.

Poly(L-lysine) (PLL) is a cationic polyelectrolyte of interest for many applications, including in therapeutic biology for DNA complexation and transfection. Several non-lysine based polycations have been shown to afford more efficient transfection in live cells than has been achieved with PLL. We find that reconfiguring polylysine into short oligolysine grafts, strung from a hydrophobic polymer backbone, gives transfection reagents greatly superior to PLL, despite having the identical cationic functional groups (i.e., exclusively primary amines). Altering the oligolysine graft length modulates DNA-polymer interactions and transfection efficiency, while incorporating the PKKKRKV heptapeptide (the Simian virus SV40 large T-antigen nuclear localization sequence) pendent groups onto the polymer backbone led to even greater transfection efficiency over the oligolysine-grafted structures. Protein expression levels obtained with these novel polymer transfection reagents were higher than, or comparable to, expression seen in the cases of JetPEI™, FuGENE® 6 and Lipofectamine™ 2000, the later being notorious for cytotoxicity that accompanies high transfection efficiency. The relative strength of the polymer-DNA complex is key to the transfection performance, as judged by serum stability and PicoGreen analysis. Moreover, polyplexes formed from our graft copolymer structures exhibit low cytotoxicity, contributing to the therapeutic promise of these novel reagents.

Aliphatic polyester terpolymers for stent coating and drug elution: effect of polymer composition on drug solubility and release.

Ring-opening terpolymerization of L-lactide (LA), -caprolactone (CL), and glycolide (GA) was performed in the presence of tin (II) 2-ethylhexanoate at 170 degrees C. Random terpolyesters with weight-average molecular weight up to 130,000 g/mol were obtained. These terpolyesters, especially those with LA:CL:GA composition of 3:1:1, provided good coating integrity following spraying onto bare metal stents. The semi-synthetic macrolide immunosuppressant, everolimus, was incorporated into the terpolyester coating, and its release from the stent was evaluated. Unlike PLLA homopolymers, which are immiscible with the drug and non-optimal for controlled release, these terpolymers gave excellent control in a screening study, by tuning terpolymer molecular weight, relative monomer ratio, and drug-to-polymer ratio. Adjusting the polymer properties to improve drug solubility (or miscibility) in the polymer coating was found beneficial to the release profile.

Polyester-graft-phosphorylcholine prepared by ring-opening polymerization and click chemistry.

Phosphorylcholine (PC)-substitution on aliphatic polyesters is accomplished by click chemistry with PC-substituted azides.