Extracting Hypothalamic Peptides with A New Magnetic Approach

A team of researchers from Shahid Beheshti University aimed to simplify the process of analyzing hypothalamic-related peptides (HRPs) by synthesizing magnetic-phthalated maltodextrin nanosponges (M-PAMDNSs) (1).

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These substances, which help stimulate hormone secretion from the anterior pituitary gland, can help treat breast cancer, prostate tumors, and other conditions. However, HRPs are currently very difficult to analyze with direct instrumentation, because of low concentration, high complexities, and interfering compounds. Sample preparation methods like liquid-liquid extraction and mixed-mode solid-phase extraction have been used to enrich and extract HRPs prior to chromatographic analysis, but these methods are time-consuming, expensive, and require a great deal of preparation. “Hence, it is of great importance to develop reliable, sensitive, rapid, green, and efficient sample preparation method for analyzing trace amount of HRPs in biological samples,” wrote the researchers in the study (1).

The team combined polysaccharides such as maltodextrins (MDs), which are viewed as low-cost and eco-friendly, and phthalic anhydride (PA), which can bond with biopolymers like starch and cellulose to introduce hydrophobic moieties and promote their adsorption capacities. The combination reduced hydrogen bonds between MD molecules and increased both its hydrophobicity and its adsorption capacities.

The resulting phthalated maltodextrins is non-toxic, low-cost, and easy to prepare. However, the phthalated maltodextrins were sensitive to water. To fix this, the group chemically crosslinked PAMDs with citric acid to create PAMD nanosponges (PAMDNSs), which, when combined with MSPE, created magnetic-PAMDNSs (M-PAMDNSs).

From there, the M-PAMDNSs were synthesized, and the materials were characterized by 1H nuclear magnetic resonance spectroscopy, water contact angle, attenuated total reflection-Fourier transform infrared spectroscopy, dynamic light scattering, zeta potential, pH point of zero charge, acid-base titration, field-emission scanning electron microscopy, Brunauer-Emmett-Teller, and vibrating sample magnetometer.

“To the best of our knowledge, this is the first research report for the introduction and application of M-PAMDNSs as efficient and green magnetic sorbents in the MSPE field,” claimed the researchers.

Though there is still more research to be done, this can potentially lead to new methods for extract HRPs.

Reference

(1) Salehpour, N.; Bayatloo, M. R.; Nojavan, S. Green hydrophobic maltodextrin nanosponges for magnetic solid-phase extraction of hypothalamic peptides from plasma samples. J. Chromatogr. A. 2023, 1706, 464220. DOI: https://doi.org/10.1016/j.chroma.2023.464220