Point of care testing (POCT) is when a test is administered at the time of consultation with near-instant availability of results; allowing the practitioner to make immediate and informed decisions about patient care. Point of care testing allows a diagnosis to be made in the fastest possible manner, when traditional testing is typically conducted in a laboratory setting.
Where is POCT done?
Point of care testing can be carried out at the bedside, or near the patient. Simplified, POCT is any testing performed in a healthcare environment which is not sent to a lab for results.
POCT can be performed in the following settings:
How is the testing done?
Lateral flow assay kits (or assay tests) represent a variety of simple techniques in which an analyte is detected via its combination (conjugation) with a target molecule embedded in, for example, a paper strip or a dip stick. Typical applications include home-based medical tests such as pregnancy tests.
The technology for most test kits is based on a staged transport of a bodily fluid (saliva, urine, or blood) in which the fluid is wicked along the first stage to a second stage, the site of bio-chemical reaction indicator. The premise of most home-based tests is that as the analyte is absorbed and reacted, an area of the strip changes color in comparison to a control strip. Gold nanospheres (GNSs) have modernized many conventional colorimetric indicators due to the inherent sensitivity of the surface plasmon resonance (SPR). Tunability of the SPR of GNRs brings a host of novel optical properties that were never attainable with GNSs e.g. large color variation in compact size regime; this feature opens up new possibilities of multiplexing to create LFA for both qualitative and quantitative analysis of multiple analytes.
How could Sona’s GNRs make a difference?
Lateral flow tests powered by Sona’s unique gold nanorods could potentially give results within minutes, while the multi-coloured spectrum of products could allow for multiple test lines per unit, and produce easy-to-read results from one small sample.
Where could Sona’s GNRs be used?
Sona’s GNRs could potentially help make diagnostic testing more efficient and effective across a broad spectrum of industries:
The ability of GNRs to be activated via surface modifications, and conjugated to specific molecules or drugs, enables the possibility of using them as drug delivery vehicles in vivo.
In fact, studies have now successfully demonstrated the efficient release of drugs within human cells upon exposure to near infrared (NIR) light. A NIR light was used to successfully trigger the release of drugs which had been conjugated to the specific GNR, with the concentration of drugs released being controlled by the NIR light irradiation time.
This GNR “tunability” and their optimal structure, which permits the addition of biological ‘payloads’, give them the potential to be used as targeted and efficient drug carriers in vivo.
Drugs and radiation used in treatment of cancers, while effective at killing tumor cells, cause damage to organs and healthy cells. Evidence suggests that GNRs could be more effective at killing tumors with less or no adverse reactions to healthy cells.
Tumor cells can be killed with heat treatment at 42-45 degrees Celsius for 15-60 minutes. However, traditional methods of this type of treatment involve non-selective irradiation, damaging the normal tissue surrounding a tumor as well as the cancerous cells. Photothermal therapy using GNRs involves the placement, intravenously or through local injection, of specifically tuned GNRs at the tumor site, accumulating the GNRs within the cancer cells, and the use of a near infrared (“NIR”) light generating laser, harmless to skin, to penetrate to the tumor, triggering the GNR’s surface electrons to vibrate strongly and increase the local temperature of the cancerous cells, thereby killing them safely. This method is less invasive and can be more precise than surgery.
This process can also be applied to other traditionally invasive procedures, such as with cosmetic surgeries like liposuction. GNRs can be modified to target fat cells in the body, making it possible to eliminate them without the use of surgery
Gold nanoparticles (GNPs) serve as great contrast agents for cell image enhancement and super-resolved imaging due to their effective surface plasmon resonance (SPR) properties, thus are not affected by photobleaching.
Yet, while most GNPs appear to offer potential benefits in this case, their optical signals are still insufficiently strong for many important real-life applications. These limitations hamper the progress in cell research by direct optical microscopy and narrow the range of phototherapy applications. By modulating the light polarization of GNRs, however, super-resolution in live cell imaging can be achieved.
Taking advantage of the polarization-dependence of gold nanorod optical properties, the ‘lock-in amplification’, widely used in electronic engineering, can be achieved in live cells and in cells that undergo apoptotic changes. This has distinct advantages in advancing real time in-vivo (RTiV) applications for monitoring inflammation in patients with cardiovascular and auto-immune diseases.