This provides a potential platform for pre-cancer screening and an easy, rapid, sensitive, cost-effective, and noninvasive supportive diagnostic tool.
Exposomes are formed in most cells and are secreted into many body fluids, such as plasma, saliva, urine, and tears. Once thought to be the dumping ground for unwanted materials from derived cells, it is now known that exomes can transport various biomolecules between cells.
Advertisement
It has also been shown that there are many surface proteins on exsomes – some common to all exsomes and others increased in response to cancer, viral infection or trauma.
In addition, tumor-derived exsomes can strongly influence tumor regulation, progression, and metastasis. Because of these possibilities, there has been much interest in using exosomes for cancer diagnosis and prognosis/treatment. However, this has been hampered by the difficulty of isolating exosomes of sufficient quantity and purity for this purpose.
Current methods involving ultracentrifuges and density gradients are tedious and time-consuming, taking at least ten hours to complete. Further difficulties are posed in the detection of isolated exosomes; The commonly used methods require expensive equipment and take up space.
Can ACSM-CL capture and detect Exosomes accurately?
The TIBI team leveraged their expertise in the design and fabrication of contact lens biosensors to eliminate the need for these isolation methods by inventing their ACSM-CL to obtain exosomes from tears, an optimal and cleaner source of exosomes than blood, urine and saliva.
They also facilitated and optimized their ACSM-CL preparation using alternative methods. When making the microchips for their lenses, the team used direct laser cutting and engraving instead of conventional casting to retain the structure of both the cavity and the lens.
In addition, the team introduced a method that chemically modified the microparticle surfaces to trigger them to bind to antibodies. This method is used in place of standard approaches, where metallic or nanocarbon materials must be used in expensive cleanroom environments.
The team then optimized the procedures to bind the capture antibody to the ACSM-CL microchip and other detectable antibody (positive control) onto the optically visible gold nanoparticles. spectrum. Both of these antibodies are specific for two different surface markers found on all exsomes.
In an initial validation trial, ACSM-CL was assayed against supernatant secreted exosomes from ten different cancer cell lines and tissues. The ability to acquire and detect exosomes was confirmed by the observed spectral shift in all tested samples, compared with negative controls. Similar results were obtained when ACSM-CL was tested on ten different tear samples collected from volunteers.
In the final experiments, exosomes in supernatants collected from three different cell lines with different surface marker expressions were tested against ACSM-CL, along with different combinations of Antibodies detect specific markers.
The resulting models of detection and non-detection of exomes from three different cell lines were as expected, thus confirming the ability of ACSM-CL to accurately capture and detect exosomes with surface markers. difference.
“Exomes are a rich source of biomarkers and molecules that can be targeted for a number of biomedical applications,” said Ali Khademhosseini, Ph.D., Director and CEO of TIBI. . “The method our team has developed greatly facilitates our ability to exploit this source.”
Source: Eurekalert
