Microencapsulated Immunoassays for Detection of Cytokines in Human Blood

Ali Rahimian, Christian Siltanen, Hamid Feyzizarnagh, Patricio Escalante, Alexander Revzin

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Cytokines are produced by leukocytes in blood and may be used as indicators of malignancies or infections. The objective of this study was to develop a strategy for immunosensing cytokines in whole, unprocessed human blood. Microfluidic droplet generation was employed to fabricate 400 μm diameter microcapsules with a hydrogel shell and an aqueous core containing sensing microbeads. The hydrogel shell was composed of poly(ethylene glycol) forming a thin (10 μm) immunoisolation layer protecting antibody-modified microbeads inside the capsule from immune cells on the outside. The microbeads were functionalized with antibodies against cytokines of interest: Interferon (IFN) and tumor necrosis factor (TNF)-α. While nonfouling, a hydrogel shell was permeable to cytokine molecules; these molecules were captured on microbeads and were detected with fluorescently labeled secondary antibodies. Calibration of encapsulated immunoassays with known concentrations of cytokines revealed a limit of detection of 14.8 and 14.4 pM for IFN and TNF-α, respectively. We also demonstrated the concept of multi-cytokine detection by fabricating distinct populations of capsules carrying either anti-IFN or anti-TNF-α microbeads and dispensing these capsules into a solution containing both cytokine types. Importantly, when placed into whole blood for 16 h, microcapsules were free of leukocytes, effectively protecting sensing beads from the blood components. To further demonstrate utility of this strategy, encapsulated microbeads were used for detection of IFN in blood of patients with latent tuberculosis infection (LTBI) and unexposed healthy controls. When compared to gold standard technology (interferon gamma release assay or IGRA), our encapsulated immunoassay accurately predicted LTBI diagnosis in 11 out of 14 patients. Overall, encapsulation of immunoassays represents a promising strategy for keeping sensing elements operational in a highly fouling complex environment such as blood.

Original languageEnglish (US)
JournalACS Sensors
DOIs
StatePublished - Jan 1 2019

Fingerprint

immunoassay
interferon
Interferons
blood
Blood
Cytokines
Capsules
necrosis
infectious diseases
capsules
antibodies
Hydrogel
tuberculosis
leukocytes
Antibodies
Hydrogels
tumors
Tumor Necrosis Factor-alpha
fouling
Molecules

Keywords

  • biosensor
  • immunoassay
  • interferon
  • latent tuberculosis infection
  • microencapsulation

ASJC Scopus subject areas

  • Bioengineering
  • Instrumentation
  • Process Chemistry and Technology
  • Fluid Flow and Transfer Processes

Cite this

Microencapsulated Immunoassays for Detection of Cytokines in Human Blood. / Rahimian, Ali; Siltanen, Christian; Feyzizarnagh, Hamid; Escalante, Patricio; Revzin, Alexander.

In: ACS Sensors, 01.01.2019.

Research output: Contribution to journalArticle

@article{ecdbdfa070f24f92a28c32ca17d11d89,
title = "Microencapsulated Immunoassays for Detection of Cytokines in Human Blood",
abstract = "Cytokines are produced by leukocytes in blood and may be used as indicators of malignancies or infections. The objective of this study was to develop a strategy for immunosensing cytokines in whole, unprocessed human blood. Microfluidic droplet generation was employed to fabricate 400 μm diameter microcapsules with a hydrogel shell and an aqueous core containing sensing microbeads. The hydrogel shell was composed of poly(ethylene glycol) forming a thin (10 μm) immunoisolation layer protecting antibody-modified microbeads inside the capsule from immune cells on the outside. The microbeads were functionalized with antibodies against cytokines of interest: Interferon (IFN) and tumor necrosis factor (TNF)-α. While nonfouling, a hydrogel shell was permeable to cytokine molecules; these molecules were captured on microbeads and were detected with fluorescently labeled secondary antibodies. Calibration of encapsulated immunoassays with known concentrations of cytokines revealed a limit of detection of 14.8 and 14.4 pM for IFN and TNF-α, respectively. We also demonstrated the concept of multi-cytokine detection by fabricating distinct populations of capsules carrying either anti-IFN or anti-TNF-α microbeads and dispensing these capsules into a solution containing both cytokine types. Importantly, when placed into whole blood for 16 h, microcapsules were free of leukocytes, effectively protecting sensing beads from the blood components. To further demonstrate utility of this strategy, encapsulated microbeads were used for detection of IFN in blood of patients with latent tuberculosis infection (LTBI) and unexposed healthy controls. When compared to gold standard technology (interferon gamma release assay or IGRA), our encapsulated immunoassay accurately predicted LTBI diagnosis in 11 out of 14 patients. Overall, encapsulation of immunoassays represents a promising strategy for keeping sensing elements operational in a highly fouling complex environment such as blood.",
keywords = "biosensor, immunoassay, interferon, latent tuberculosis infection, microencapsulation",
author = "Ali Rahimian and Christian Siltanen and Hamid Feyzizarnagh and Patricio Escalante and Alexander Revzin",
year = "2019",
month = "1",
day = "1",
doi = "10.1021/acssensors.8b01033",
language = "English (US)",
journal = "ACS Sensors",
issn = "2379-3694",
publisher = "American Chemical Society",

}

TY - JOUR

T1 - Microencapsulated Immunoassays for Detection of Cytokines in Human Blood

AU - Rahimian, Ali

AU - Siltanen, Christian

AU - Feyzizarnagh, Hamid

AU - Escalante, Patricio

AU - Revzin, Alexander

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Cytokines are produced by leukocytes in blood and may be used as indicators of malignancies or infections. The objective of this study was to develop a strategy for immunosensing cytokines in whole, unprocessed human blood. Microfluidic droplet generation was employed to fabricate 400 μm diameter microcapsules with a hydrogel shell and an aqueous core containing sensing microbeads. The hydrogel shell was composed of poly(ethylene glycol) forming a thin (10 μm) immunoisolation layer protecting antibody-modified microbeads inside the capsule from immune cells on the outside. The microbeads were functionalized with antibodies against cytokines of interest: Interferon (IFN) and tumor necrosis factor (TNF)-α. While nonfouling, a hydrogel shell was permeable to cytokine molecules; these molecules were captured on microbeads and were detected with fluorescently labeled secondary antibodies. Calibration of encapsulated immunoassays with known concentrations of cytokines revealed a limit of detection of 14.8 and 14.4 pM for IFN and TNF-α, respectively. We also demonstrated the concept of multi-cytokine detection by fabricating distinct populations of capsules carrying either anti-IFN or anti-TNF-α microbeads and dispensing these capsules into a solution containing both cytokine types. Importantly, when placed into whole blood for 16 h, microcapsules were free of leukocytes, effectively protecting sensing beads from the blood components. To further demonstrate utility of this strategy, encapsulated microbeads were used for detection of IFN in blood of patients with latent tuberculosis infection (LTBI) and unexposed healthy controls. When compared to gold standard technology (interferon gamma release assay or IGRA), our encapsulated immunoassay accurately predicted LTBI diagnosis in 11 out of 14 patients. Overall, encapsulation of immunoassays represents a promising strategy for keeping sensing elements operational in a highly fouling complex environment such as blood.

AB - Cytokines are produced by leukocytes in blood and may be used as indicators of malignancies or infections. The objective of this study was to develop a strategy for immunosensing cytokines in whole, unprocessed human blood. Microfluidic droplet generation was employed to fabricate 400 μm diameter microcapsules with a hydrogel shell and an aqueous core containing sensing microbeads. The hydrogel shell was composed of poly(ethylene glycol) forming a thin (10 μm) immunoisolation layer protecting antibody-modified microbeads inside the capsule from immune cells on the outside. The microbeads were functionalized with antibodies against cytokines of interest: Interferon (IFN) and tumor necrosis factor (TNF)-α. While nonfouling, a hydrogel shell was permeable to cytokine molecules; these molecules were captured on microbeads and were detected with fluorescently labeled secondary antibodies. Calibration of encapsulated immunoassays with known concentrations of cytokines revealed a limit of detection of 14.8 and 14.4 pM for IFN and TNF-α, respectively. We also demonstrated the concept of multi-cytokine detection by fabricating distinct populations of capsules carrying either anti-IFN or anti-TNF-α microbeads and dispensing these capsules into a solution containing both cytokine types. Importantly, when placed into whole blood for 16 h, microcapsules were free of leukocytes, effectively protecting sensing beads from the blood components. To further demonstrate utility of this strategy, encapsulated microbeads were used for detection of IFN in blood of patients with latent tuberculosis infection (LTBI) and unexposed healthy controls. When compared to gold standard technology (interferon gamma release assay or IGRA), our encapsulated immunoassay accurately predicted LTBI diagnosis in 11 out of 14 patients. Overall, encapsulation of immunoassays represents a promising strategy for keeping sensing elements operational in a highly fouling complex environment such as blood.

KW - biosensor

KW - immunoassay

KW - interferon

KW - latent tuberculosis infection

KW - microencapsulation

UR - http://www.scopus.com/inward/record.url?scp=85062329258&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062329258&partnerID=8YFLogxK

U2 - 10.1021/acssensors.8b01033

DO - 10.1021/acssensors.8b01033

M3 - Article

C2 - 30776214

AN - SCOPUS:85062329258

JO - ACS Sensors

JF - ACS Sensors

SN - 2379-3694

ER -