Described herein are compositions and techniques related to generation and therapeutic application of artificial synapses. Artificial synapses are engineered extracellular vesicles, including exosomes, which incorporate sticky binders on their surface to anchor signaling domains against biological targets, such as receptors. These engineered additives can be organized in genetic vector constructs, expressed in mammalian cells, wherein the sticky binders attach to extracellular vesicles such as exosomes, thereby presenting their joined signaling domains which are rapidly taken up by recipient cells. Artificial synapses adopt the hallmark biophysical and biochemical features of extracellular vesicles, allowing for rapid deployment and scale-up. Importantly, this strategy can allow for kinetically favorable signal generation and signal propagation. This includes, for example, increasing density of agonist presentation to support receptor clusteringan onerous barrier for traditional receptor targeting strategies.

Compounds useful as biologically active compounds are disclosed. The compounds have the following structure (I):

##STR00001##

or a stereoisomer, tautomer or salt thereof, wherein R.sup.1, R.sup.2, R.sup.3, L, L.sup.1, L.sup.2, L.sup.3, L.sup.4, M and n are as defined herein. Methods associated with preparation and use of such compounds are also provided.

Compounds useful as biologically active compounds are disclosed. The compounds have the following structure (I):

##STR00001##

or a stereoisomer, tautomer or salt thereof, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, L, L.sup.1, L.sup.2, L.sup.3, L.sup.4, M, q, w and n are as defined herein. Methods associated with preparation and use of such compounds is also provided.

Described herein are compositions and techniques related to generation and therapeutic application of artificial synapses. Artificial synapses are engineered extracellular vesicles, including exosomes, which incorporate sticky binders on their surface to anchor signaling domains against biological targets, such as receptors. These engineered additives can be organized in genetic vector constructs, expressed in mammalian cells, wherein the sticky binders attach to extracellular vesicles such as exosomes, thereby presenting their joined signaling domains which are rapidly taken up by recipient cells. Artificial synapses adopt the hallmark biophysical and biochemical features of extracellular vesicles, allowing for rapid deployment and scale-up. Importantly, this strategy can allow for kinetically favorable signal generation and signal propagation. This includes, for example, increasing density of agonist presentation to support receptor clusteringan onerous barrier for traditional receptor targeting strategies.

The present invention relates generally to hybrid polymer (e.g., polyphosphazene) based drug delivery platforms and to methods of producing, evaluating, administering, and treating subjects with the same. More particularly, the present invention provides polyphosphazene based drug delivery platforms comprising one or more polyphosphazenes with controlled molecular weights and/or polydispersities as well as selective methods for associating one or more therapeutic drug (or prodrug) substances to the polyphosphazenes.

The present invention relates to a nucleic acid for transfection, in which a nucleic acid targeted for introduction into a cell and a cell membrane-permeable group are linked together, and the cell membrane-permeable group has a structure represented by one of general formulas (A1) to (A4) (wherein in the formulas: R.sup.0 represents an alkyl group of 1 to 30 carbon atoms which may have an ether-bonded oxygen atom between carbon atoms and may be substituted with one or more fluorine atoms; n11, n12, n13 and n14 each independently represent an integer of 1 or greater; B represents a nucleic acid base; R.sup.FE represents a perfluoroalkyl group of 1 to 10 carbon atoms which may have an ether-bonded oxygen atom between carbon atoms; na represents an integer of 1 to 10; and the black dots indicate bonding sites).

##STR00001##

Monodisperse structures with precise numbers of polymer arms and oligonucleotide chains conjugated to a backbone are disclosed. The structures, referred to miktoarm conjugates, are resistant to nuclease degradation and are capable of regulating gene expression in the absence of a co-carrier.

The present invention relates generally to hybrid polymer (e.g., polyphosphazene) based drug delivery platforms and to methods of producing, evaluating, administering, and treating subjects with the same. More particularly, the present invention provides polyphosphazene based drug delivery platforms comprising one or more polyphosphazenes with controlled molecular weights and/or polydispersities as well as selective methods for associating one or more therapeutic drug (or prodrug) substances to the polyphosphazenes.

Compounds useful as biologically active compounds are disclosed. The compounds have the following structure (I) or a stereoisomer, tautomer or salt thereof, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, L, L.sup.1, L.sup.2, L.sup.3, M, m and n are as defined herein. Methods associated with preparation and use of such compounds is also provided. ##STR00001##

Compounds useful as biologically active compounds are disclosed. The compounds have the following structure (I): ##STR00001##
or a stereoisomer, tautomer or salt thereof, wherein R.sup.1, R.sup.2, R.sup.3, L, L.sup.1, L.sup.2, L.sup.3, L.sup.4, M, m and n are as defined herein. Methods associated with preparation and use of such compounds is also provided.