With the rapid development of micro systems technology and microelectronics, smart implantable wireless electronic systems are emerging for the continuous surveillance of relevant parameters in the body and even for closed-loop systems with a sensor feed-back to drug release systems. With respect to diabetes management, there is a critical societal need for a fully integrated sensor array that can be used to continuously measure a patient’s blood glucose concentration, pH, pCO2 and colloid oncotic pressure twenty four hours a day on a long-term basis. In this work, thin films of metabolite-specific or “smart” hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain “chemomechanical sensors” that can serve as selective and versatile wireless biomedical sensors and sensor arrays for a continuous monitoring of several metabolites. Sensor response time and accuracy with which sensors can track gradual changes in glucose, pH, CO2 and ionic strength, respectively, was estimated in vitro using simulated physiological solutions. The biocompatibility and hermeticity of the developed multilayer encapsulation for the microsensor array has been investigated concerning the long-term stability and enduring functionality that is desired for permanent implants.

The Sso10b (or Alba) family of proteins is a conserved group of archaeal and eukaryotic proteins which are thought to play a role in both chromatin organization and RNA metabolism. We describe here the solution structure and properties of Sso10b2 from Sulfolobus solfataricus. NMR data including residual dipolar couplings and (15)N relaxation data demonstrated that the protein adopts a beta(1)alpha(1)beta(2)alpha(2)beta(3)beta(4) topology with an IF-3-like fold. The protein dimerizes in solution at 30 degrees C via a hydrophobic surface defined by the C-terminal alpha(2)beta(3)beta(4) elements with a structure similar to one of the putative dimers indicated by previous crystal structures. DSC and circular dichroism data demonstrated an unusual two-state structural transition near the growth temperature which led to an increase in beta-sheet content without dissociation of the dimer. The cooperativity of the transition exceeded that of a dimer at pH 7, demonstrating the presence of higher order oligomers near the growth temperature at pH 7. Reverse titrations of Sso10b2 with nucleic acid showed that the protein binds single-stranded DNA (K(d) of 3 x 10(-)(7) M) with higher affinity than RNA (1.3 x 10(-)(6) M) or double-stranded DNA (1.5 x 10(-)(5) M) in 10 mM KH(2)PO(4) (pH 7.0, 20 degrees C). NMR chemical shift perturbation data indicated that single-stranded DNA and RNA binding occurred across the same dimer interface and encompassed a surface defined by the C-terminal ends of the beta(1), beta(2), and beta(3) strands of each monomer.

Poly(ethylene glycol) (PEG) is often used to biocompatibilize surfaces of implantable biomedical devices. Here, block copolymers consisting of PEG and l‐cysteine‐containing poly(amino acid)s (PAA's) were synthesized as polymeric multianchor systems for the covalent attachment to gold surfaces or surfaces decorated with gold nanoparticles. Amino‐terminated PEG was used as macroinitiator in the ring‐opening polymerization, (ROP), of respective amino acid N‐carboxyanhydrides (NCA's) of l‐cysteine (l‐Cys), l‐glutamate (l‐Glu), and l‐lysine (l‐Lys). The resulting block copolymers formed either diblock copolymers, PEG‐b‐p(l‐Glux‐co‐l‐Cysy) or triblock copolymers, PEG‐b‐p(l‐Glu)x‐b‐p(l‐Cys)y. The monomer feed ratio matches the actual copolymer composition, which, together with high yields and a low polydispersity, indicates that the NCA ROP follows a living mechanism. The l‐Cys repeat units act as anchors to the gold surface or the gold nanoparticles and the l‐Glu repeat units act as spacers for the reactive l‐Cys units. Surface analysis by atomic force microscopy revealed that all block copolymers formed homogenous and pin‐hole free surface coatings and the phase separation of mutually immiscible PEG and PAA blocks was observed. A different concept for the biocompatibilization of surfaces was followed when thiol‐terminated p(l‐Lys) homopolymer was first grafted to the surface and then covalently decorated with HOOC‐CH2‐PEG‐b‐p(Bz‐l‐Glu) polymeric micelles. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 248–257

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