Intranasal spray formulation containing rizatriptan benzoate for the treatment of migraine.

Rizatriptan produces antimigraine activity by acting as selective agonist of 5-HT1B and 5-HT1D receptors present on intracranial and extracerebral blood vessels. Absorption from oral tablet is slow with Tmax of approximately 1-1.5 h. A few attempts have been made to promote rapid absorption such as oral or sublingual films with limited success. The aim of our study was to develop intranasal spray formulation of rizatriptan with quick onset of action. Solubility was enhanced by a co-solvent system where we studied solubility of rizatriptan benzoate in pure solvents, binary and ternary mixtures. Binary and ternary co-solvents using ethanol, water, propylene glycol and polyethylene glycol resulted rizatriptan equivalent base solubility more than 60 mg/mL. Same co-solvents were used at different level to make nasal spray formulations and evaluated pharmacokinetics using beagle dog animal model. Nasal spray formulation containing 20% w/w ethanol exhibited highest exposure, where Cmax (312 ng/mL) reached in 5 min and maintained higher concentration than oral dose for more than 30 min.

Accelerated Materials Discovery Using Chemical Informatics Investigation of Polymer Physicochemical Properties and Transgene Expression Efficacy.

Quantitative approaches to structure-property relationships are critical for the accelerated design and discovery of biomaterials in biotechnology and medicine. However, the absence of definitive structures, unlike those available for small molecules or 3D crystal structures available for some proteins, has limited the development of Quantitative Structure-Property Relationship (QSPR) models for investigating physicochemical properties and biological activity of polymers. In this study, we describe a combined experimental and cheminformatics paradigm for first developing QSPR models of polymer physicochemical properties, including molecular weight, hydrophobicity, and DNA-binding activity. Quantitative Structure-Activity Relationship (QSAR) models of polymer-mediated transgene expression were then developed using these physicochemical properties with an eye towards developing a novel two-step chemical informatics paradigm for determining biological activity (e.g., transgene expression) of polymer properties as related to physicochemical properties. We also investigated a more conventional approach in which biomaterial efficacy, i.e., transgene expression activity, was directly correlated to structural representations of the polymers used for delivering plasmid DNA. Our generalized chemical informatics approach can accelerate the discovery of polymeric biomaterials for several applications in biotechnology and medicine, including in nucleic acid delivery.

Synthesis of Cationic Polymer Libraries for Gene Delivery Using Diglycidyl Ethers.

Gene therapy has the potential to cure many different genetic diseases, if safe and effective gene delivery vectors can be developed. This chapter describes protocols for the synthesis of novel polymers using diglycidyl ether and diamine or polyamine monomers for transgene delivery and expression. The resulting poly (amino ethers) are able to transfect a higher number of cells, with lower cytotoxicity than other commercially available polymers (e.g., Polyethyleneimine, PEI).

Chemomechanically engineered 3D organotypic platforms of bladder cancer dormancy and reactivation.

Tumors undergo periods of dormancy followed by reactivation leading to metastatic disease. Arrest in the G0/G1 phase of the cell cycle and resistance to chemotherapeutic drugs are key hallmarks of dormant tumor cells. Here, we describe a 3D platform of bladder cancer cell dormancy and reactivation facilitated by a novel aminoglycoside-derived hydrogel, Amikagel. These 3D dormant tumor microenvironments (3D-DTMs) were arrested in the G0/G1 phase and were highly resistant to anti-proliferative drugs. Inhibition of targets in the cellular protein production machinery led to induction of endoplasmic reticulum (ER) stress and complete ablation of 3D-DTMs. Nanoparticle-mediated calcium delivery significantly accelerated ER stress-mediated 3D-DTM death. Transfer of 3D-DTMs onto weaker and adhesive Amikagels resulted in selective reactivation of a sub-population of N-cadherin deficient cells from dormancy. Whole-transcriptome analyses further indicated key biochemical differences between dormant and proliferative cancer cells. Taken together, our results indicate that 3D bladder cancer microenvironments of dormancy and reactivation can facilitate fundamental advances and novel drug discovery in cancer.

Development of a Web-Enabled SVR-Based Machine Learning Platform and its Application on Modeling Transgene Expression Activity of Aminoglycoside-Derived Polycations.

OBJECTIVE: Support Vector Regression (SVR) has become increasingly popular in cheminformatics modeling. As a result, SVR-based machine learning algorithms, including Fuzzy-SVR and Least Square-SVR (LS-SVR) have been developed and applied in various research areas. However, at present, few downloadable packages or public-domain software are available for these algorithms. To address this need, we developed the Support vector regression-based Online Learning Equipment (SOLE) web tool (available at http://reccr.chem.rpi.edu/SOLE/index.html) as an online learning system to support predictive cheminformatics and materials informatics studies. RESULTS: In this work, we employed the SOLE system to model transgene expression efficacy of polymers obtained from aminoglycoside antibiotics, which allowed the results of several modeling approaches to be easily compared. All models had test set r2 of 0.96-0.98 and test set R2 of 0.79-0.84. Y-scrambling test showed the models were stable and not over-fitted. CONCLUSION: SOLE has a user-friendly interface and includes routine elements of performing QSAR/QSPR studies that can be applied in various research areas. It utilizes rational and sophisticated feature selection, model selection and model evaluation processes.

Temperature responsive chemical crosslinkable UV pretreated hydrogel for application to injectable tissue regeneration system via differentiations of encapsulated hMSCs.

An injectable hydrogel showing temperature-dependent chemical crosslinking was developed to combine injectabilities of physical hydrogels with dense structures of chemical hydrogels for applications in stem cell delivery-mediated tissue regeneration systems showing easy administration and maintenance of well-dispersed cells within the hydrogel. Hydrophobic methacryl groups were applied to thermosensitive poly(organophosphazenes) to induce temperature mediated hydrophobic interaction and chemical crosslinking. UV pretreated polymer solution showed chemical crosslinking not before injection only after injection into the body even it was already exposed to UV. As this injectable hydrogel showed small pore-sizes, it was guessed cell holding without any adhesive moieties were available and showed the potentials for a cell scaffold. In this study, temperature dependent chemical crosslinking and proliferation and differentiation of the encapsulated hMSCs into various tissues were observed in the hydrogels after injection.

Quaternization enhances the transgene expression efficacy of aminoglycoside-derived polymers.

The objective of the present study was to synthesize and investigate the transgene expression efficacy of quaternized derivatives of aminoglycoside polymers in different cancer cell lines. A series of glycidyltrimethylammonium chloride (GTMAC) derivatives of aminoglycoside polymers (GTMAC-AM polymers), containing varying degrees of quaternization (13-45%), were synthesized. The structures and properties of GTMAC-AM polymers were investigated using FT-IR and (1)H NMR spectroscopy. Physicochemical factors that influence transgene expression efficacy including DNA binding, hydrodynamic size, zeta potential and cytotoxicity, were determined. Formation of polymer-plasmid DNA complexes was also visualized using atomic force microscopy. GTMAC-AM polymers demonstrated higher transgene expression efficacies compared to their parent polymers, 25 kDa poly(ethyleneimine), as well as Lipofectamine-3000. Our results indicate that quaternization enhances the transgene expression efficacy and reduces the cytotoxicity of aminoglycoside-derived polymers, making it an attractive strategy for nucleic acid delivery with these new materials.

Parallel Synthesis and Quantitative Structure-Activity Relationship (QSAR) Modeling of Aminoglycoside-Derived Lipopolymers for Transgene Expression.

We describe the parallel synthesis of lipopolymers generated by conjugating alkanoyl chlorides to polymers derived from aminoglycoside antibiotic monomers as novel vehicles for transgene delivery and expression in mammalian cells. Parallel screening of lipopolymers led to the identification of six leads that demonstrated higher transgene expression efficacies in several cancer cells, when compared to the parental polymers as well as 25 kDa poly(ethylene imine), a current standard for polymer-mediated transgene expression. Quantitiative structure-activity relationship (QSAR)-based cheminformatics modeling was employed in order to investigate the role of lipopolymer physicochemical properties (molecular descriptors) on transgene expression efficacy. The predictive ability of the QSAR model, investgated using lipopolymers not employed for training the model, demonstrated excellent agreement with experimentally observed transgene expression. Our findings indicate that lipid substitution on aminoglycoside-derived polymers results in high levels of transgene expression compared to unsubstituted polymers. Taken together, these materials show significant promise in nonviral transgene delivery with several applications in biotechnology and medicine.

Aminoglycoside antibiotic-derived anion-exchange microbeads for plasmid DNA binding and in situ DNA capture.

Plasmid DNA (pDNA) therapeutics are being investigated for gene therapy and DNA vaccines against diseases including cancer, cystic fibrosis and AIDS. In addition, several applications in modern biotechnology require pDNA for transient protein production. Here, we describe the synthesis, characterization, and evaluation of microbeads ("Amikabeads") derived from the aminoglycoside antibiotic amikacin for pDNA binding and in situ DNA capture from mammalian cells. The parental aminoglycoside-derived microbeads (Amikabeads-P) acted as anion-exchange materials, and demonstrated high capacities for binding pDNA. Binding of pDNA was significantly enhanced following quaternization of the amines on the microbeads (Amikabeads-Q). Amikabeads were further employed for the disruption and extraction of DNA from mammalian cells, indicating their utility for in situ DNA capture. Our results indicate that Amikabeads are a novel material, with multiple reactive groups for further conjugation, and can have several applications in plasmid DNA biotechnology.

Parallel synthesis of poly(amino ether)-templated plasmonic nanoparticles for transgene delivery.

Plasmonic nanoparticles have been increasingly investigated for numerous applications in medicine, sensing, and catalysis. In particular, gold nanoparticles have been investigated for separations, sensing, drug/nucleic acid delivery, and bioimaging. In addition, silver nanoparticles demonstrate antibacterial activity, resulting in potential application in treatments against microbial infections, burns, diabetic skin ulcers, and medical devices. Here, we describe the facile, parallel synthesis of both gold and silver nanoparticles using a small set of poly(amino ethers), or PAEs, derived from linear polyamines, under ambient conditions and in absence of additional reagents. The kinetics of nanoparticle formation were dependent on PAE concentration and chemical composition. In addition, yields were significantly greater in case of PAEs when compared to 25 kDa poly(ethylene imine), which was used as a standard catonic polymer. Ultraviolet radiation enhanced the kinetics and the yield of both gold and silver nanoparticles, likely by means of a coreduction effect. PAE-templated gold nanoparticles demonstrated the ability to deliver plasmid DNA, resulting in transgene expression, in 22Rv1 human prostate cancer and MB49 murine bladder cancer cell lines. Taken together, our results indicate that chemically diverse poly(amino ethers) can be employed for rapidly templating the formation of metal nanoparticles under ambient conditions. The simplicity of synthesis and chemical diversity make PAE-templated nanoparticles useful tools for several applications in biotechnology, including nucleic acid delivery.

Sensitizing cancer cells to TRAIL-induced death by micellar delivery of mitoxantrone.

TNFα-related apoptosis-inducing ligand (TRAIL) induces death selectively in cancer cells. However, subpopulations of cancer cells are either resistant to or can develop resistance to TRAIL-induced death. As a result, strategies that overcome this resistance are currently under investigation. We have recently identified several US FDA-approved drugs with TRAIL-sensitization activity against prostate, breast and pancreatic cancer cells. Mitoxantrone, a previously unknown TRAIL sensitizer identified in the screen, was successfully encapsulated in methoxy-, amine- and carboxyl-terminated PEG-DSPE micelles in order to facilitate delivery of the drug to cancer cells. All three micelle types were extensively characterized for their physicochemical properties and evaluated for their ability to sensitize cancer cells to TRAIL-induced death. Our results indicate that micelle-encapsulated mitoxantrone can be advantageously employed in synergistic treatments with TRAIL, leading to a biocompatible delivery system and amplified cell killing activity for combination chemotherapeutic cancer treatments.

Discovery of antibiotics-derived polymers for gene delivery using combinatorial synthesis and cheminformatics modeling.

We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and 'building block' polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology.

Polymer-enhanced delivery increases adenoviral gene expression in an orthotopic model of bladder cancer.

Gene therapy has garnered significant attention as a therapeutic approach for bladder cancer but efficient delivery and gene expression remain major hurdles. The goal of this study was to determine if cationic polymers can enhance adenoviral gene expression in cells that are difficult to transduce in vitro and to subsequently investigate lead candidates for their capacity to increase adenoviral gene expression in an orthotopic in vivo model of bladder cancer. In vitro screening of linear polyamine-based and aminoglycoside-based polymer libraries identified several candidates that enhanced adenoviral reporter gene expression in vitro. The polyamine-based polymer NPGDE-1,4 Bis significantly enhanced adenoviral gene expression in the orthotopic model of bladder cancer but unfortunately further use of this polymer was limited by toxicity. In contrast, the aminoglycoside-based polymer paromomycin-BGDE, enhanced adenoviral gene expression within the bladder without adverse events. Our study demonstrates for the first time that cationic polymers can enhance adenoviral gene expression in an orthotopic model of bladder cancer, thereby providing the foundation for future studies to determine therapeutic benefits of polymer-adenovirus combination in bladder cancer gene therapy.

Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

Generation of a focused poly(amino ether) library: polymer-mediated transgene delivery and gold-nanorod based theranostic systems.

A focused library of twenty-one cationic poly(amino ethers) was synthesized following ring-opening polymerization of two diglycidyl ethers by different oligoamines. The polymers were screened in parallel for plasmid DNA (pDNA) delivery, and transgene expression efficacies of individual polymers were compared to those of 25 kDa polyethylenimine (PEI), a current standard for polymer-mediated transgene delivery. Seven lead polymers that demonstrated higher transgene expression than PEI in pancreatic and prostate cancer cells lines were identified from the screen. All seven lead polymers showed highest transgene expression at a polymer:pDNA weight ratio of 5:1 in the MIA PaCa-2 pancreatic cancer cell line. Among the conditions studied, transgene expression efficacy correlated with minimal polymer cytotoxicity but not polyplex sizes. In addition, this study indicated that methylene spacing between amine centers in the monomers, amine content, and molecular weight of the polymers are all significant factors and should be considered when designing polymers for transgene delivery. A lead effective polymer was employed for coating gold nanorods, leading to theranostic nanoassemblies that possess combined transgene delivery and optical imaging capabilities, leading to potential theranostic systems.

Discovery of cationic polymers for non-viral gene delivery using combinatorial approaches.

Gene therapy is an attractive treatment option for diseases of genetic origin, including several cancers and cardiovascular diseases. While viruses are effective vectors for delivering exogenous genes to cells, concerns related to insertional mutagenesis, immunogenicity, lack of tropism, decay and high production costs necessitate the discovery of non-viral methods. Significant efforts have been focused on cationic polymers as non-viral alternatives for gene delivery. Recent studies have employed combinatorial syntheses and parallel screening methods for enhancing the efficacy of gene delivery, biocompatibility of the delivery vehicle, and overcoming cellular level barriers as they relate to polymer-mediated transgene uptake, transport, transcription, and expression. This review summarizes and discusses recent advances in combinatorial syntheses and parallel screening of cationic polymer libraries for the discovery of efficient and safe gene delivery systems.

Design of polyphosphazene hydrogels with improved structural properties by use of star-shaped multithiol crosslinkers.

The feasibility of using a star-shaped crosslinker to produce a hydrogel with controlled mechanical properties and degradation rates was investigated. The aqueous blends of functional polymers and crosslinkers formed a solution at low temperature and a hydrogel with desired mechanical properties at body temperature. The introduction of star-shaped crosslinkers affected the microscopic and macroscopic properties of the hydrogel. The fabricated hydrogels could be suitable for many potential biomedical applications because of their injectability, tunable mechanical properties, controlled degradation rate and gel formation under physiological conditions.

Injectable, dual cross-linkable polyphosphazene blend hydrogels.

A new class of injectable, self cross-linkable, and thermosensitive polyphosphazene-based blending systems of functional thiolated and acrylated polymers was designed and synthesized to develop an ideal injectable carrier, and to overcome many barriers associated with developing the injectable carriers, such as the uses of monomeric crosslinkers, catalysts, oxidants, pH adjustments, initiators, UV light, heat production and organic solvent. The aqueous solutions of the polymer blends were exhibited a solution state at low temperature, and transformed into a hydrogel state with desired mechanical strength at body temperature via thermosensitive hydrophobic interactions. The mechanical strength was further improved by the cross-linking of thiol groups with acrylate groups in the polymer network under physiological conditions. The thermoresponsive hydrophobic interactions in the polymer network accelerated the chemical cross-linking to improve the mechanical property. The mechanical strength, inner three-dimensional network, and degradation rate can be tuned through the degree of cross-linking between the thermosensitive and functional blended polymers. The results suggest that the self cross-linkable thermosensitive polyphosphazene blend systems have great potentials to play a crucial role as an injectable carrier because of their improved suitable mechanical properties for application potentials, in addition to their inherent advantages such as injectable, biodegradable and thermosensitive properties.

Dual cross-linking systems of functionally photo-cross-linkable and thermoresponsive polyphosphazene hydrogels for biomedical applications.

Photo-cross-linkable, functionalized, and thermosensitive polyphosphazenes were synthesized to develop a dual cross-linking system with properties of mechanically suitable strength and controllable biodegradation for injectable biomedical applications. The aqueous solutions of the polymers exhibited sol-gel transition behaviors against temperature. The incorporated methacrylate groups were photo-cross-linked upon UV light under mild conditions, which resulted in the formation of compact three-dimensional networks. The thermoresponsive hydrophobic interactions at body temperature facilitated the rapid dual cross-linking accomplishment of the photo-cross-linking even under mild conditions. The characteristics of the polymers such as pore size and density showed that the inner three-dimensional networks depended on the degree of cross-linking of methacrylate units. Mechanical properties of the gel were also improved several folds after developing the photo-cross-linking in the network from the in vivo degradation studies. The results demonstrate that the photo-cross-linkable and thermoresponsive polyphosphazenes have great potential as injectable, biodegradable, and controllable carriers for various biomedical applications by tuning the mechanical gel property and the degradation rate.

Rapid photocrosslinkable thermoresponsive injectable polyphosphazene hydrogels.

Rapidly photocrosslinkable and thermosensitive polyphosphazene polymers have been prepared to overcome the limitations associated with long UV exposure. Short UV exposure on the thermosensitive gels under mild conditions leads to quick photocrosslinking of the acrylate groups in the polymer network, and results in a dual crosslinked network with enhanced mechanical strength. The accelerated photocrosslinking can be attributed to the high reactivity of the acrylate double bond and hydrophobic interactions in the polymer network. The effects on the degree of photocrosslinking of the UV light intensity and the concentration of the photoinitiator were studied. In vitro and in vivo photocrosslinkings were accomplished within 120 and 180 s of exposure times, respectively. The degradation rate of the polymers depended on the degree of acrylate substitution in the polymer network. These results demonstrate that the injectable hydrogels with desired mechanical properties and degradation rates can be created in situ under mild photocrosslinkable conditions, and the dual crosslinkable acrylated poly(organophosphazenes) may hold great promise for biomedical delivery applications of biological molecules, cells, and drugs.