Aptamer selection and aptasensor construction for bone density biomarkers

Raja Chinnappan; Norhan Sameh Zaghloul; Razan AlZabn; Abeer Malkawi; Anas Abdel Rahman; Khalid M Abu-Salah; Mohammed Zourob

doi:10.1016/j.talanta.2020.121818

Aptamer selection and aptasensor construction for bone density biomarkers

Talanta. 2021 Mar 1:224:121818. doi: 10.1016/j.talanta.2020.121818. Epub 2020 Oct 29.

Authors

Raja Chinnappan¹, Norhan Sameh Zaghloul², Razan AlZabn¹, Abeer Malkawi³, Anas Abdel Rahman⁴, Khalid M Abu-Salah², Mohammed Zourob⁵

Affiliations

¹ Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Rd, Riyadh, 11533, Saudi Arabia.
² Department of Cellular Therapy and Cancer Research-Nanomedicine Section, King Abdullah International Medical Research Center/ King Saud Bin Abdulaziz University for Health Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.
³ Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Zahrawi Street, Al Maather, Riyadh, 12713, Saudi Arabia.
⁴ Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Zahrawi Street, Al Maather, Riyadh, 12713, Saudi Arabia; Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia; Department of Chemistry, College of Science, Memorial University of Newfoundland, St. JOhn's, NL, A1B 3X7, Canada.
⁵ Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Rd, Riyadh, 11533, Saudi Arabia; Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia. Electronic address: mzourob@alfaisal.edu.

PMID: 33379043
DOI: 10.1016/j.talanta.2020.121818

Abstract

Osteoporosis (OP) is a bone disease involved in dysregulation of one of the bone metabolism arms, formation, or desorption cause a porous bone. Osteocalcin (OC) and beta-crosslap (BC), are the well-known markers for OP, which are connected to bone formation and desorption, respectively. In addition to the OP biomarker, BC is also used as an estrogen replacement therapeutic monitoring. ELISA and other antibody-based detection methods are routinely used for measuring OC and BC. These methods have limitations that include thermostability, sensitivity, sacrificing animals, and cost of production. However, aptamer-based-assays are of interest to overcome these drawbacks and achieve the most specific and robust application. Herein, specific aptamers for OC and BC were selected by the systematic evolution of ligands by exponential enrichment (SELEX) method from the pool of ssDNA library with 60 random sequences. The binding affinity (K_d) of the selected aptamers were evaluated against the respective biomarkers. The high-affinity aptamers of OC and BC showed the K_d values of 59 and 55 nM respectively. A graphene oxide-based aptasensors were fabricated from the high-affinity aptamers, and the detection limits of OC and BC were found to be 0.4 pg/ml and 0.21 pg/ml, respectively. These aptasensors have been tested with OC and BC spiked buffer samples and validated using serum samples collected from osteoporotic rats.

Keywords: Aptamer; Aptasensor; Beta-crosslap; Biosensor; FRET; Graphene-oxide; Osteocalcin; Osteoporosis.

MeSH terms

Animals
Aptamers, Nucleotide*
Biomarkers
Bone Density
DNA, Single-Stranded / genetics
Rats
SELEX Aptamer Technique*

Substances

Aptamers, Nucleotide
Biomarkers
DNA, Single-Stranded