The novelty and the sensitivity of PCCAs at low glucose concentrations are the impetus for this editorial, in which I examine the contact lens construct as a NI glucose testing modality.
Asher's group have constructed a photonic glucose sensor in the form of thin acrylamide PCCA hydrogel films that contain glucose molecular recognition elements (3, 6, 7).
With these limited reports on the relationship between tear and blood glucose, the critical test is measurement of [DELTA][lambda] for a PCCA as a function of blood glucose concentration in an animal model and/or human volunteers.
The presented PCCA data suggest a simple in vitro calibration of [DELTA][lambda] vs tear-glucose concentration in artificial tear fluid (3), but in vivo calibration must correlate [DELTA][lambda] with the blood glucose concentration.
Founded in 1953, PCCA
is a farmer-owned cotton marketing and warehousing cooperative serving about 15,000 members.
Diffraction from the polymerized crystalline colloidal array (PCCA) was measured by a Spectral Instruments SI 400 diode array spectrometer.
The PCCA hydrogel backbone was hydrolyzed in a solution containing 0.1 mol/L NaOH and 100 mL/L N,N,N',N'-tetramethylethylenediamine for 3 h to convert amide groups to carboxylates.
The gel diffraction after AFBA attachment returned almost to the visible spectral wavelength characteristic of the original nonhydrolyzed PCCA, indicating that most of the carboxyl groups linked to the boronic acid derivatives.
We developed an aminoethylation route (Scheme 2) for our PCCA photonic materials that preserves the CCA ordering and diffraction.
The AA-PEG PCCA on a quartz plate was transferred stepwise from pure water to DMSO by 200 mL/L incremental increases in the relative DMSO concentration.
PCCA President and CEO Wally Darneille echoed Arias's sentiments.
PCCA is a producer-owned cotton marketing cooperative headquartered in the center of the "world's biggest cotton patch," representing 55 to 60 percent of U.S.