Lauren

Searching Methods!

A molecular imprint nanosensor for ultrasensitive detection of proteins -->"Here, we show that arrays of carbon nanotube (nanotube) tips imprinted with a non-conducting polymer coating can recognize proteins with subpicogram per litre sensitivity using electrochemical impedance spectroscopy." -->Basically an alternative to antibodies. -->Process in brief: First: copolymerization of functional monomers and cross-linkers around template molecules. Then remove template, leaving complementary binding sites that will recognize the template. -->Cheaper and more stable than Abs. -->In the paper, they use the molecules for detection, but perhaps could be used for therapy/diagnostics. -->Global health!!!
 * As of 9/27/2011**

from Stanford: Carbon Nanotubes as Molecular Transporters and Carriers for Drug, Gene Therapy and Protein Delivery -->Briefly: attach the molecule to a single-walled carbon nanotube. Administer in vitro or in vivo as an aqueous suspension. Special applications to T cells and cancer cells, which are hard to transfect. -->Paper demonstrating that they enter cells (couldn't download: http://pubs.acs.org.ezp-prod1.hul.harvard.edu/doi/abs/10.1021/ja0486059)

from Stanford: Delivering RNAi to In-vivo Targets Using Polymer Encapsulation -->"method for encapsulating siRNA for controlled release and targeted delivery. This method results in stable nanoparticles less than 200 nm in size with reduced immunogenicity. The FDA approved encapsulating polymers used in these particles are biodegradable and nontoxic." -->Posters listed as the references; data aren't as impressive as the title.

from Stanford: Encapsidation of Heterologous Entities into Virus-like Particles  (couldn't upload: http://onlinelibrary.wiley.com/doi/10.1002/bit.21716/pdf)

--> They say: "sRNAi, toxic material, small proteins, probes, or markers, can be encapsulated by the particle." "The investigators have demonstrated use of this method to encapsidate a fluorophore. Additionally, they have successfully used cell-free synthesis to encapsidate a firefly luciferase shRNA into VLPs."  --> The paper they reference only outlines the synthesis of the particles, not any delivery results.

Much better page - Below, I've included only the most promising ideas/technologies.
 * As of 9/23/2011**

Intranasal delivery to the brain --> found in //Nature Biotech// --> This refers to a mode of delivery rather than a therapy, but we were initially looking at possibilities in neurobio, and delivery across the blood-brain barrier is a great challenge. The idea is that vasculature is rich in the nasal cavity, and compounds can be delivered to the circulation can cross the blood-brain barrier. More importantly, migraines, smell/taste loss, and Alzheimer’s disease have all apparently been treated //without crossing the BBB // via intranasal delivery. This technology seems to be in animal models now.

Priming mice with thymosin-beta4 --> cardiomyocytes repair injured heart -->//Letters to Nature// --> Authors delivered thymosin-beta4 to mice, induced myocardial infarction, and detected regeneration from a progenitor population of epicardial origin. --> This study has very clear implications, but perhaps we could take it to a different organ system. Thymosin-beta4 was a "peptide previously shown to restore vascular potential to adult epicardium-derived progenitor cells with injury"; these authors tried delivery directly to the heart, and it worked.

PUF proteins bind any RNA sequence -->Review from //Cell// and Brief Communication from //Nature// --> "PUF proteins are found in most eukaryotes and are typically involved in regulating embryogenesis, development and differentiation." --> They usually have 8 RNA-binding repeats, but they can be engineered to have 16 and bind nearly any sequence with specificity. --> Recently, researchers have figured out a sequence to bind cytodine, and thus they have a way to bind each base. --> Better than RNAi because: "use of short RNA duplexes to target RNAs is limited to lowering their abundance or expression in the cytoplasm, and this depends on RNA interference pathways. Engineering RNA-binding proteins is attractive because they could be fused to any desired effector domain, enabling selective binding of a specific RNA target to investigate or manipulate any aspect of its metabolism." (Both activating and repressing PUF proteins have been discovered).

Genome modification with Zinc Finger Nucleases or TAL Effectors --> from //Nature Methods// and //Nature Biotech// --> ZFNs are site-specific nucleases which induce double-stranded breaks for knocking out genes (like CCR5 in HIV+ patients, as in [|this clinical trial]) or inducing homologous recombination. --> ZFNs can knock out genes or "correct" them if donor DNA is provided for homolgy-directed repair ([|multiple possible outcomes]). --> ZFN gene correction example: "We show that zinc-ﬁnger nucleases designed against an X-linked severe combined immune deﬁciency (SCID) mutation in the IL2Rg gene yielded more than 18% gene-modiﬁed human cells without selection. Remarkably, about 7% of the cells acquired the desired genetic modiﬁcation on both X chromosomes, with cell genotype accurately reﬂected at the messenger RNA and protein levels." --> TAL effectors bind DNA specifically and can upregulate or edit genes. Compared to ZFNs, more flexible, require less optimization, and are less toxic.

Porphysomes --> Nanoparticles made of the natural pigment porphyrin combine desirable properties of both organic and inorganic particles. --> Phorphyrin-lipid conjugates form a structure with a bilayer --> The paper demonstrates potential application for photothermal therapy, but the construct might biodegrade relatively quickly, and could perhaps be used for delivery therapy. The paper mentions that it should be relatively easy to incorporate antibodies, aptamers, proteins or small targeting molecules into the particles.