This paper reviews the development of coronary stents from a polymer scientist's view point, and presents the first results of an interdisciplinary team assembled for the development of new stent systems. Poly(styrene-b-isobutylene-b-styrene) block copolymer (SIBS), a nanostructured thermoplastic elastomer, is used in clinical practice as the drug-eluting polymeric coating on the Taxus coronary stent (trademark of Boston Scientific Co.). Our group has been developing new architectures comprising of arborescent (dendritic) polyisobutylene cores (D_SIBS), which were shown to be as biocompatible as SIBS. ElectroNanospray (Nanocopoeia Inc.) was used to coat test coupons and coronary stents with selected D(S)IBS polymers loaded with dexamethasone, a model drug. The surface topology varied from smooth to nanosized particulate coating. This paper will demonstrate how drug release profiles were influenced by both the molecular weight of the polyisobutylene core and spraying conditions of the polymer-drug mixture.

Monoclonal antibody 4E9, which was raised against a partially purified detergent extract of rat caudal epididymal sperm, recognizes the tail of sperm from the cauda, but not from caput epididymidis, as well as epithelial cells in a restricted region of the distal caput/corpus epididymidis and proteins in epididymal fluid from corpus and cauda epididymidis. The antigen is apparently a glycoprotein, since it is retained on a Ricinus communis agglutinin I lectin column. Epididymal fluid antigens have apparent M(rs) of 38-26 kD, whereas the membrane-associated form of the molecule has an M(r) of 26 kD. Immunocytochemical data and Western immunoblot data suggest that the membrane antigen is derived from the fluid antigen, which, in turn, is secreted by the epididymal epithelium. Characterization of the membrane antigen indicates that it is tightly associated with the sperm surface, behaving as though it is an integral membrane protein. The antigen persists on ejaculated sperm.

We examine a process of preparing oil-in-water nanoemulsions by quenching (diluting and cooling) precursor microemulsions made with nonionic surfactants and a cosurfactant. The precursor microemulsion structure is varied by changing the concentration of the cosurfactant. Water-continuous microemulsions produce initial nanoemulsion structures that are small and simple, mostly unilamellar vesicles, but microemulsions that are not water-continuous produce initial nanoemulsion structures that are larger and multilamellar. Examination of these structures by cryo-electron microscopy supports the hypothesis that they are initially vesicular structures formed via lamellar intermediate structures, and that if the lamellar structures are too well ordered they fail to produce small simple structures.

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Matrix stones are radiolucent bodies that present as soft muco-proteinaceous material within the renal collecting system. Following wide-angle X-ray diffraction (XRD) and scanning electron microscopy (SEM), we homogenized a surgically removed matrix stone, extracted and purified protein, and analyzed samples using tandem mass spectrometry for proteomic composition. Resulting spectra were searched using ProteinPilot 2.0, and identified proteins were reported with >95% confidence. Primary XRD mineral analysis was a biological apatite, and SEM revealed fibrous, net-like laminations containing bacterial, cellular, and crystalline material. Of the 33 unique proteins identified, 90% have not been previously reported within matrix stones and over 70% may be considered inflammatory or defensive in nature. Characterization of other matrix stone proteomes, in particular from non-infectious populations, may yield insights into the pathogenesis of this rare stone as well as the mineralogical process that occurs within crystalline calculi.