Peptide/Nanoparticle Biointerfaces for Multistep Tandem Catalysis.

The realization of multifunctional nanoparticle systems is essential to achieve highly efficient catalytic materials for specific applications; however, their production remains quite challenging. They are typically achieved through the incorporation of multiple inorganic components; however, incorporation of functionality could also be achieved at the organic ligand layer. In this work, we demonstrate the generation of multifunctional nanoparticle catalysts using peptide-based ligands for tandem catalytic functionality.

Bioinspired carbon nanotube fuzzy fiber hair sensor for air-flow detection.

Artificial hair sensors consisting of a piezoresistive carbon-nanotube-coated glass fiber embedded in a microcapillary are assembled and characterized. Individual sensors resemble a hair plug that may be integrated in a wide range of host materials. The sensors demonstrate an air-flow detection threshold of less than 1 m/s with a piezoresistive sensitivity of 1.

Selective sensing of vapors of similar dielectric constants using peptide-capped gold nanoparticles on individual multivariable transducers.

Peptide-capped AYSSGAPPMPPF gold nanoparticles were demonstrated for highly selective chemical vapor sensing using individual multivariable inductor-capacitor-resistor (LCR) resonators. Their multivariable response was achieved by measuring their resonance impedance spectra followed by multivariate spectral analysis. Detection of model toxic vapors and chemical agent simulants, such as acetonitrile, dichloromethane and methyl salicylate, was performed.

Determining the feasibility of utilizing the microbicide applicator compliance assay for use in clinical trials.

Introduction: Participant's adherence to use of study product is a major concern in microbicide clinical trials, which can impact on proving product efficacy. In a previously described assay, single-use microbicide applicators exposed to the vagina were tested by spraying the applicator with trypan blue dye, resulting in vaginal mucus staining on inserted applicators. As subjects in our Phase 3 trials return applicators only at quarterly visits, often mixing inserted and not-inserted applicators together in the same bag, cross-contamination could confound results.

Patterned silk films cast from ionic liquid solubilized fibroin as scaffolds for cell growth.

Silk is an attractive biomaterial for use in tissue engineering applications because of its slow degradation, excellent mechanical properties, and biocompatibility. In this report, we demonstrate a simple method to cast patterned films directly from silk fibroin dissolved in an ionic liquid. The films cast from the silk ionic liquid solution were found to support normal cell proliferation and differentiation.

Carrageenan/MIV-150 (PC-815), a combination microbicide.

Objective: The objective of this article is to study the effect of PC-815, a novel combination microbicide containing carrageenan and the nonnucleoside reverse transcriptase inhibitor (NNRTI) MIV-150, in blocking HIV-1 and HIV-2 infections in vitro as compared with Carraguard alone.

Goal: The goal of this study was to develop a combination microbicide that is more efficacious than Carraguard against HIV-1 and HIV-2.

Study Design: The microtiter syncytial assay was used to evaluate: 1) the antiviral and virucidal activity of MIV-150 against HIV-1MN; 2) the additive effect of MIV-150 when combined with carrageenan; and 3) a possible interference of seminal fluid in the antiviral activity of these compounds.

Thermally induced alpha-helix to beta-sheet transition in regenerated silk fibers and films.

The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study.

Dissolution and regeneration of Bombyx mori silk fibroin using ionic liquids.

In this work, the suitability of imidazolium-based ionic liquid solvents is investigated for the dissolution and regeneration of silkworm (Bombyx mori) silk. Within an ionic liquid the anion plays a larger role in dictating the ultimate solubility of the silk. The dissolution of the silk in the ionic liquid is confirmed using wide-angle X-ray scattering.

Lubricants containing N-9 may enhance rectal transmission of HIV and other STIs.

It has been shown that men who have sex with men actively seek lubricants that contain nonoxynol-9 (N-9) because they believe that N-9 may help to prevent infection by HIV. However, indirect evidence suggests that N-9 may actually enhance infection. Microscopic examination of rectal lavage and biopsy specimens collected at different time points following rectal application of a lubricant containing 2% N-9 showed rapid exfoliation of the rectal epithelium.

Assay for establishing whether microbicide applicators have been exposed to the vagina.

Objectives: To develop an accurate, rapid, and inexpensive method for verifying vaginal applicator use.

Goal: To develop a method for assessing compliance in microbicide clinical trials.

Study Design: Single use Microlax applicators containing a placebo formulation either were or were not exposed to the vagina.

Relative safety of sexual lubricants for rectal intercourse.

Objective: The current study was conducted to determine the relative safety of sexual lubricants for rectal use.

Goal: Our goal was to identify a sexual lubricant that would not damage the rectal epithelium.

Study Design: We describe a mouse assay to determine the degree to which lubricants cause rectal sloughing.

Human genital epithelial cells capture cell-free human immunodeficiency virus type 1 and transmit the virus to CD4+ Cells: implications for mechanisms of sexual transmission.

Sexual transmission of human immunodeficiency virus (HIV) accounts for the majority of new infections worldwide. However, the mechanism of viral transmission across the mucosal barrier is poorly understood. By use of an ectocervical epithelium-derived cell line, we found that the cells are capable of sequestering large amounts of HIV particles but are refractory to cell-free viral infection.

Carrageenan formulation prevents macrophage trafficking from vagina: implications for microbicide development.

Considerable evidence suggests that human immunodeficiency virus (HIV)-infected macrophages and/or lymphocytes may mediate sexual transmission of HIV. We and others have previously demonstrated that when vitally stained donor mouse lymphocytes or macrophages are placed in the vaginas of mice, some of the stained cells can later be found in the iliac lymph nodes. The aim of this study was to assess the extent of mononuclear cell trafficking from the vagina and to test the possibility that carrageenan formulation, a sulfated polysaccharide formulation containing 3% PDR98-15 carrageenan (PC-515; FMC Biopolymer, Rockland, ME), a vaginal microbicide, would prevent vaginal transmigration of macrophages.

The Development of Microbicides for Clinical Use to Prevent Sexually Transmitted Diseases.

Approximately 60 vaginal microbicides are under development for the prevention of HIV/AIDS and other sexually transmitted pathogens. The history and current status of the field are discussed with emphasis on the lessons learned from recent clinical trials, along with an emphasis on the mechanisms involved in the sexual transmission of HIV and how this information influences microbicide development. Additionally, the current status of in vitro and animal systems used for evaluating microbicide efficacy, as well as the challenges involved in developing more appropriate and practical assays, are discussed.

Difference in the Manner of Association of Acrosome-Intact and Acrosome-Reacted Hamster Spermatozoa with Egg Microvilli as revealed by Scanning Electron Microscopy: (hamster/sperm-egg association/scanning electron microscopy).

Scanning electron microscopy was employed to examine the manner of association between in vitro capacitated spermatozoa and zona-free eggs of the hamster. Spermatozoa with intact acrosomes, which were unable to fuse with eggs, were seen in general associated with egg microvilli in the region of the acrosomal cap. Acrosome-reacting spermatozoa were seen associated with egg microvilli with the dissociating acrosomal caps.