Tehran University of Medical Sciences Nanomedicine Research Journal 2476-3489 10 3 2025 09 01 Synthesis and structural characterization of folic acid-conjugated mesoporous silica nanoparticles loaded with thymol and investigating their cytotoxic effects on HT-29 colorectal cancer cells 306 315 732280 10.22034/nmrj.2025.03.009 EN Nafiseh Gharaei Golvarzeh Department of Biology, Ma.C., Islamic Azad University, Mashhad, Iran Masoud Homayuni-tabrizi Department of Biology, Ma.C., Islamic Azad University, Mashhad, Iran Ali Es-haghi Department of Biology, Ma.C., Islamic Azad University, Mashhad, Iran 0000-0001-5292-6161 Journal Article 2025 07 18 The gradual malignant transformation of normal cells can result from DNA lesions caused by endogenous errors during replication, inherent chemical instability of some DNA bases, or oxidative damage due to free radicals produced during metabolism. Colorectal cancer (CRC) poses a major health threat and a model to study the molecular mechanisms involved in the malignancy. In terms of origin, CRC can be either familial, hereditary, or without a traceable link to these factors. Researchers have been seeking targeted treatments for CRC. In the early 1990s, upon the discovery of M41S molecular sieves, mesoporous silica materials and subsequently nanoparticles (MSNs) attracted special attention as they could offer promising features in terms of tunable physiochemical and structural characteristics (e.g., drug release, stability, size, and porosity), suggesting them as drug carriers, biosensors, etc. MSNs are safe toward various cells and can be easily internalized by them, as another distinctive feature of MSNs. In this research, folate-coated MSNs were loaded with thymol and subjected to anticancer activity analysis, including cytotoxicity (MTT test) and apoptosis (AOPI staining by flow cytometry). The average size of MSNs was 296.40 nm with semi-spherical morphology. Significant anti-growth activity was observed against HT29 cancer cells, which was associated with apoptosis induction, confirmed by AOPI staining. These results highlighted the anticancer properties of MSNs against CRC cells. https://www.nanomedicine-rj.com/article_732280_3815f67adb768bc89a65565a49794c6d.pdf