Abstract: Nanoclusters comprising inorganic nanocrystals and a biodegradable polymer are disclosed. The inorganic nanocrystals have a mean particle size of 1 to 500 nm. The inorganic nanocrystals are contained within a core of the nanoclusters, on the surface of the nanoclusters, contained within a core of the nanoclusters, dispersed throughout the nanoclusters, or a combination thereof. The biodegradable polymer allows the inorganic nanocrystals to be excreted renally over a period of time. The nanoclusters can be used for medical imaging or other biomedical applications.

Abstract: Nanoclusters comprising inorganic nanocrystals and a biodegradable polymer are disclosed. The inorganic nanocrystals have a mean particle size of 1 to 500 nm. The inorganic nanocrystals are contained within a core of the nanoclusters, on the surface of the nanoclusters, contained within a core of the nanoclusters, dispersed throughout the nanoclusters, or a combination thereof. The biodegradable polymer allows the inorganic nanocrystals to be excreted renally over a period of time. The nanoclusters can be used for medical imaging or other biomedical applications.

Abstract: The invention relates to sulfonimide bearing phenolic compounds and the use of those compounds to produce polyphosphazenes functionalized by one or more of those compounds alone, or in combination with cosubstituents. The invention also relates to blends of sulfonimide functionalized phosphazene polymers with other polymers, membranes formed of the functionalized polymers, and the use of those membranes in devices such as fuel cells.

Abstract: Polymeric nanofibers have been developed which are useful in a variety of medical and other applications, such as filtration devices, medical prosthesis, scaffolds for tissue engineering, wound dressings, controlled drug delivery systems, cosmetic skin masks, and protective clothing. These can be formed of any of a variety of different polymers, either non-degradable or degradable. In a preferred embodiment demonstrated in the following examples, nanofibers are formed of biodegradable and non biodegradable polyphosphazenes, their blends with other polyphosphazenes or with organic, inorganic/organometallic polymers as well as composite nanofibers of polyphosphazenes with nanosized particles such as hydroxyapatites.

Abstract: Biodegradable polymeric compositions are provided, wherein biodegradable polyphosphazenes are combined with at least one other polymer, either in the form of a blend, a semi-interpenetrating network (semi-IPN), or an interpenetrating network IPN. The side groups and composition of the polyphosphazenes are used to determine the properties of the compositions, for example, the rate and extent of degradation, and mechanical properties. These are useful in biomedical applications, including controlled drug delivery and tissue regeneration, and environmental applications. In the most preferred embodiment, as demonstrated by the examples, the polyphosphazenes contain hydrophobic side groups, such as p-methylphenoxy and other aromatic groups, and groups which impart hydrolytic instability, such as amino acid alkyl esters, and degrade by surface erosion. A preferred example is ethyl glycinato-substituted polyphosphazene (PPHOS) with p-methylphenoxy as co-substituent.