Selective Adsorption of Human Testosterone from Plasma Using Zn^2⁺-Loaded Hexanediamine–Chitosan Beads

This study aimed to develop a novel adsorbent, Zn^2⁺ -loaded hexanediamine-chitosan (HDA-CS) beads, for the selective removal of human testosterone from plasma. The preparation involved synthesizing chitosan beads, modifying them with hexanediamine to enhance adsorption capacity and subsequently loading them with zinc ions. The effects of the HDA spacer, Zn²⁺ concentration, and adsorption time on the adsorption percentage for testosterone were systematically investigated through a series of adsorption experiments. Results indicated that the Zn^2⁺ -HDA-CS beads achieved a maximum adsorption capacity of approximately 35% within 90 min. The analysis of plasma concentrations of Zn^2⁺ , albumin, and sex hormone-binding globulin (SHBG) indicated that the adsorption process involved a complex interaction between testosterone-bound SHBG and albumin for Zn^2⁺ binding sites on the beads. Additionally, the adsorbent demonstrated good storage stability and selectivity for testosterone, with minimal impact on total protein content in plasma. These findings highlight the potential of Zn^2⁺ -HDA-CS beads as an effective therapeutic option for managing testosterone levels in clinical settings, particularly in patients undergoing androgen deprivation therapy for prostate cancer.