pH indicator swabs for biomonitoring and diagnostics
Inventors
Jabbarzadeh, Ehsan • ESLAMBOLCHIMOGHADAM, SARA
Assignees
Publication Number
US-12196684-B2
Publication Date
2025-01-14
Expiration Date
2039-08-20
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Abstract
Medical swabs incorporating a pH indicator in an absorbent crosslinked hydrogel matrix. The medical swabs can provide for visual monitoring of biological pH. The medical swabs can be used to monitor wounds, such as chronic wounds, burn wounds, surgical wounds, etc., as well as other biological fluids. The swabs can be used for early detection of chronic wounds and/or early detection of bacterial infections.
Core Innovation
The invention discloses medical swabs incorporating a pH indicator within an absorbent crosslinked hydrogel matrix. These swabs are designed to provide for rapid, visually detectable monitoring of the pH of biological fluids, such as wound exudate or other body secretions, directly through a color change visible to the naked eye. The pH indicator remains retained within the hydrogel matrix, preventing leaching and enabling consistent measurement.
The problem being addressed is that existing colorimetric pH indicator systems often require a reagent to extract biological materials and generate a detectable color, leading to increased cost, complexity, and the risk of dye leaching or error. Traditional pH measuring devices are difficult to use, sometimes requiring regular calibration and fragile electrodes, and existing diagnostic methods for wound infection rely on slow and error-prone microbiological testing, delaying treatment and negatively impacting outcomes.
The invented swabs offer a one-step, simple test for pH, requiring only visual inspection for a color change, with no special equipment needed. The absorbent, biocompatible hydrogel matrix serves both as a capture substrate and as a medium for containing the pH indicator, which can be any suitably responsive colorimetric indicator such as litmus, anthocyanin, or bromothymol blue. Through direct application to tissue or fluid, the swab can aid in early detection of infection or abnormal conditions through pH changes, especially useful in wound care and monitoring.
Claims Coverage
There is one independent claim describing a method for forming a medical swab with several inventive features.
Forming a precursor solution containing a pH indicator, photoinitiator, and crosslinkable biocompatible polymer
A precursor solution is formed that includes: - A pH indicator - A photoinitiator - A crosslinkable biocompatible polymer This solution is foundational to the construction of the swab, combining all necessary reactive and functional components in advance.
Coating the precursor solution on a support substrate
The precursor solution containing the selected pH indicator and polymer is coated onto the surface of a support substrate. The support substrate can be absorptive, and may comprise fibers, foam, sponge, or materials such as polyurethane, polyester, or cotton. The coating method can include application on individual fibers.
Crosslinking the biocompatible polymer to form a crosslinked absorbent hydrogel matrix that retains the pH indicator and includes a plasticizer
After coating, the biocompatible polymer in the precursor solution is crosslinked to form a stable, absorbent hydrogel matrix. The matrix securely retains the pH indicator and includes a plasticizer to modify mechanical properties. Crosslinking can be initiated by a crosslinking agent or environmental condition, depending on the system used.
The independent claim defines a method that enables production of a medical swab with a pH indicator retained in a crosslinked, plasticized hydrogel matrix on a support, enabling simple, colorimetric pH detection in medical contexts.
Stated Advantages
Provides simple, rapid, and visually readable monitoring of biological pH without the need for special equipment or additional reagents.
Enables early detection of chronic wounds and bacterial infections, allowing earlier therapeutic intervention and potentially improved patient outcomes.
Reduces cost, complexity, and potential for error compared to traditional pH measurement methods or laboratory diagnostics.
Incorporates a non-toxic, biocompatible, and absorbent hydrogel matrix, making the swabs suitable for frequent and ongoing monitoring.
Prevents dye leaching and secures the indicator for reliable, repeatable results.
Documented Applications
Monitoring wounds, including chronic wounds, burn wounds, surgical wounds, ulcers, traumatic injuries, bedsores, diabetic wounds, and other external or internal wounds.
Early detection of chronic wounds and early detection of bacterial infections by visual determination of pH changes.
Monitoring pH in various biological fluids and tissues, including sweat, vaginal secretions, urine, saliva, amniotic fluids, blood, mucus, and nasal surfaces.
Assessing the status of skin diseases or irregularities by detecting pH abnormalities.
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