Polystyrene latex microspheres are efficient supports for immunological reactions. In the presence of suitable functional groups these microspheres may react by covalent binding with antigens or antibodies and have been extensively used in immunoassay technique. By using the emulsion polymerization and diazotization methods, a kind of functionalized latex was prepared. The preparation of this latex consisted of six syntheses of polystyrene followed by nitration, amination and diazotization. A narrow distribution of particle size was obtained in all the cases. The synthesis that presented 98% of monomer conversion and the largest particle size diameter 0.2 ± 0.05 μm was chosen for the subsequent chemical treatments. The chemical characterizations of every step were performed by Fourier transform infrared and Raman spectroscopies. The particle size was determined by a submicrometer particle analyzer and scanning electron microscopy. The polydiazostyrene latex obtained was sensitized using bovine serum albumin (BSA) and when it was submitted to agglutination assay in the presence of a rabbit serum containing specific antibodies to BSA demonstrated efficient results. © 1997 John Wiley & Sons, Ltd.

Insulin is a life-saving medication for people with type 1 diabetes, but traditional insulin replacement therapy is based on multiple daily subcutaneous injections or continuous subcutaneous pump-regulated infusion. Nonphysiologic delivery of subcutaneous insulin implies a rapid and sustained increase in systemic insulin levels due to the loss of concentration gradient between portal and systemic circulations. In fact, the liver degrades about half of the endogenous insulin secreted by the pancreas into the venous portal system. The reverse insulin distribution has short- and long-term effects on glucose metabolism. Thus, researchers have explored less-invasive administration routes based on innovative pharmaceutical formulations, which preserve hormone stability and ensure the therapeutic effectiveness. This review examines some of the recent proposals from clinical and material chemistry point of view, giving particular attention to patients’ (and diabetologists’) ideal requirements that organic chemistry could meet.

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The preparation and characterization of aminated polystyrene-based latexes as attainable by dispersion polymerization technique are reported. Mixtures of Boc-p-aminostyrene and styrene monomers at various compositions were copolymerized under dispersion conditions in 2-propanol/water 3:1 by volume in the presence of alpha,alpha'-azobis(isobutyronitrile) as free radical initiator at 75 degrees C. Copolymer microspheres with uniform size distributions and average diameters comprised between 0.9 and 1.8 mu m were obtained. Aminated microspheres were obtained by the simple removal of the Boc protective group under acidic conditions followed by neutralization, thus leading to p-aminostyrene/styrene copolymers. These chemical treatments when carried out under mild conditions (room temperature and dilute acid and basic solutions), demonstrated to be efficient without causing any major alteration of the microspheres morphology. XPS analysis of the prepared microspheres showed an increase of NH2 groups with the increasing of the Boc-p-aminostyrene in the copolymer feed up to 10 mol %

Polyurethanes (PUs) composed by hard and soft segments have been extensively used in the manufacturing of biocompatible prosthesis and medical devices. A broad variety of PUs can be obtained by modifying the balance between both segments. In the present work, different basically‐flexible PUs have been prepared by employing different combinations of aliphatic hexamethylene diisocyanate, poly(ethylene glycol) (Mw 400 Da), poly(ϵ‐caprolactone) diol (Mw 530 Da), and 1,4‐butanediol. Thermal analysis of the synthesized PUs demonstrated high thermal stability and the assumption of glassy state well below room temperature, in agreement with their marked flexibility. Morphological characterization of PUs films indicated that films prepared by spin coating were smoother and more homogeneous than those obtained by casting. Biological assays performed by using 3T3/BALB‐C mouse embryo fibroblast cell line confirmed the absence of toxicity and hence the biocompatibility of PU‐films.