title: Efficient on-chip isolation of HIV subtypes.
abstract: HIV has caused a global pandemic over the last three decades. There is an unmet need to develop point-of-care (POC) viral load diagnostics to initiate and monitor antiretroviral treatment in resource-constrained settings. Particularly, geographical distribution of HIV subtypes poses significant challenges for POC immunoassays. Here, we demonstrated a microfluidic device that can effectively capture various subtypes of HIV particles through anti-gp120 antibodies, which were immobilized on the microchannel surface. We first optimized an antibody immobilization process using fluorescent antibodies, quantum dot staining and AFM studies. The results showed that anti-gp120 antibodies were immobilized on the microchannel surface with an elevated antibody density and uniform antibody orientation using a Protein G-based surface chemistry. Further, RT-qPCR analysis showed that HIV particles of subtypes A, B and C were captured repeatably with high efficiencies of 77.2 ± 13.2%, 82.1 ± 18.8, and 80.9 ± 14.0% from culture supernatant, and 73.2 ± 13.6, 74.4 ± 14.6 and 78.3 ± 13.3% from spiked whole blood at a viral load of 1000 copies per mL, respectively. HIV particles of subtypes A, B and C were captured with high efficiencies of 81.8 ± 9.4%, 72.5 ± 18.7, and 87.8 ± 3.2% from culture supernatant, and 74.6 ± 12.9, 75.5 ± 6.7 and 69.7 ± 9.5% from spiked whole blood at a viral load of 10,000 copies per mL, respectively. The presented immuno-sensing device enables the development of POC on-chip technologies to monitor viral load and guide antiretroviral treatment (ART) in resource-constrained settings.
authors.affiliation: Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Harvard-MIT Health Sciences and Technology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 65 Landsdowne St., # 267, Cambridge, MA 02139, USA.
authors.forename: ShuQi
authors.initials: S
authors.lastname: Wang
authors.forename: Matin
authors.initials: M
authors.lastname: Esfahani
authors.forename: Umut A
authors.initials: UA
authors.lastname: Gurkan
authors.forename: Fatih
authors.initials: F
authors.lastname: Inci
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Kuritzkes
authors.forename: Utkan
authors.initials: U
authors.lastname: Demirci
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology*; D006678:HIV / Q000276:immunology / Q000302:isolation & purification*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000097:blood / Q000821:virology; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D013499:Surface Properties; D019562:Viral Load / Q000379:methods*
chemical_list: D055910:Antibodies, Immobilized; D015699:HIV Envelope Protein gp120