Overcoming limitations of conventional solvent exchange methods: Achieving monodisperse non-equilibrium polymer micelles through equilibration-nanoprecipitation (ENP).

Hypothesis Conventional solvent exchange formulation methods face limitations when trying to control the final non-equilibrium size properties of block copolymer micelles containing a strongly hydrophobicity and a rigid block because the solvent conditions are not well controlled during micelle formation. Therefore, using an alternative formulation method, named Equilibration-Nanoprecipitation (ENP), in which micelles are formed under uniform solvent conditions, will significantly reduce the final dispersity compared a conventional solvent exchange method. EXPERIMENTAL: Size properties of the final aqueous micelle dispersions formed from the ENP method and a conventional solvent exchange are measured using DLS.

Bioactivity of 11 keto and hydroxy androgens in yeast and mammalian host cells.

Recent studies have highlighted the potential role of 11oxygenated (keto or hydroxy) androgens in human reproductive function with 11keto androgens circulating at concentrations comparable with testosterone in women and children. However, the intrinsic androgenic bioactivities of 11 keto and hydroxy androgens are not fully characterized. We therefore investigated the full androgen dose-response curves using complementary in vitro yeast and mammalian (HEK293) host cell bioassays of 11 keto and hydroxy derivatives of the potent androgens, testosterone (T) and dihydrotestosterone (DHT), compared with their parent non-11 oxygenated steroids together with the pro-androgen precursor (androstenedione (A)) and metabolites (androstanedione, androsterone).

Nontargeted detection of designer androgens: Underestimated role of in vitro bioassays.

Androgens, both steroidal and nonsteroidal in nature, are among the most commonly misused substances in competitive sports. Their recognized anabolic and performance enhancing effects through short- and long-term physiological adaptations make them popular. Androgens exist as natural steroids, or are chemically synthesized as anabolic androgenic steroids (AAS) or selective androgen receptor modulators (SARMs).

In vivo metabolism of the designer anabolic steroid hemapolin in the thoroughbred horse.

Hemapolin (2α,3α-epithio-17α-methyl-5α-androstan-17β-ol) is a designer steroid that is an ingredient in several "dietary" and "nutritional" supplements available online. As an unusual chemical modification to the steroid A-ring could allow this compound to pass through antidoping screens undetected, the metabolism of hemapolin was investigated by an in vivo equine drug administration study coupled with GC-MS analysis. Following administration of synthetically prepared hemapolin to a thoroughbred horse, madol (17α-methyl-5α-androst-2-en-17β-ol), reduced and dihydroxylated madol (17α-methyl-5α-androstane-2β,3α,17β-triol), and the isomeric enone metabolites 17β-hydroxy-17α-methyl-5α-androst-3-en-2-one and 17β-hydroxy-17α-methyl-5α-androst-2-en-4-one, were detected and confirmed in equine urine extracts by comparison with a library of synthetically derived reference materials.

Androgen Bioassay for the Detection of Nonlabeled Androgenic Compounds in Nutritional Supplements.

Both athletes and the general population use nutritional supplements. Athletes often turn to supplements hoping that consuming the supplement will help them be more competitive and healthy, while the general population hopes to improve body image or vitality. While many supplements contain ingredients that may have useful properties, there are supplements that are contaminated with compounds that are banned for use in sport or have been deliberately adulterated to fortify a supplement with an ingredient that will produce the advertised effect.

The use of tandem yeast and mammalian cell in vitro androgen bioassays to detect androgens in internet-sourced sport supplements.

Sport supplements containing steroids never approved for therapeutic use have the potential for abuse by athletes. Most are marketed online and may contain undisclosed steroids yet are readily available despite lacking toxicological or pharmacological evaluation. In this study, 18 supplements purchased online underwent organic solvent extraction to isolate any steroids they contained.

In vitro androgen bioassays as a detection method for designer androgens.

Androgens are the class of sex steroids responsible for male sexual characteristics, including increased muscle mass and decreased fat mass. Illicit use of androgen doping can be an attractive option for those looking to enhance sporting performance and/or physical appearance. The use of in vitro bioassays to detect androgens, especially designer or proandrogens, is becoming increasingly important in combating androgen doping associated with nutritional supplements.