Molecularly imprinted polymers coupled to matrix assisted laser desorption ionization mass spectrometry for femtomoles detection of cardiac troponin I peptides

Abstract

Molecularly imprinted polymers (MIPs) were combined to MALDI-TOF-MS to evaluate a selective enrichment (SE) method for the determination of clinically relevant biomarkers from complex biological samples. The concept was proven with the myocardial injury marker Troponin I (cTnI). In a first part, MIP materials entailed for the recognition of cTnI epitopes (three peptides selected) were prepared and characterized in dimensions (0.7-2μm), dissociation constants (58-817 nM), kinetics of binding (5-60 min), binding capacity (ca. 1.5 µg/mg polymer), imprinting factors (3 > IF > 5) and selectivity for the peptide epitope. Then, the MIPs, incubated with cTnI peptides and spotted on the target with the DHB matrix, were assayed for the desorption of the peptides in MALDI-TOF-MS. The measured detection limit was ca. 300 femtomols. Finally, the MIP-SE MALDI-TOF-MS was tested for its ability to enrich in the cTnI peptides from a complex sample, mimic of serum (i.e. 81 peptides of digested albumin). The MIP-SE MALDI-TOF-MS successfully enriched in cTnI peptides from the complex sample proving the technique could offer a flexible platform to prepare entailed materials suitable for diagnostic purposes.

Molecularly imprinted polymers by epitope imprinting: a journey from molecular interactions to the available bioinformatics resources to scout for epitope templates

“…Such a variety imposes readjusting the imprinting process for each kind of epitope, as will be discussed later. In fact, in dependence to its localization within the protein sequence, the epitope can be terminal, such as C-or N-terminal peptides, as reported in several examples [35,37,38], or localized within the sequence and therefore internal [39,40] (Fig. 2A).…”

Epitope Imprinting Technology: Progress, Applications, and Perspectives toward Artificial Antibodies

“…Cenci et al combined epitope‐imprinted materials with MALDI‐TOF‐MS to evaluate a selective enrichment method developed for the detection of a clinically relevant biomarker, myocardial injury marker Troponin I (cTnI), in complex biological samples . The epitopes were the three peptides AK9 (AYATEPHAK), NK11 (NITEIADLTQK), and NR11 (NIDALSGMEGR).…”

Evaluation of Molecularly Imprinted Polymers for Point-of-Care Testing for Cardiovascular Disease

“…The authors appear to imply that the microspheres, possibly due to the increased surface area, facilitate the capture of a higher concentration of Myo, and thus potentially support the fabrication of a biomimetic sensor with a wide linear range of detection. A PIP synthesised to detect cTnI epitopes achieved a maximum binding capacity of approximately 1.5 mg/g within an optimal time of 60 min [218]. In this work, fingerprint analysis was conducted to identify three distinct epitopes that were used as templates for the PIP, which was synthesised in bulk and subsequently grinded to micron dimensions.…”