en public specific orginal article <div style="text-align: justify;"><span style="font-size:11pt"><span style="line-height:115%"><span calibri="" style="font-family:"><b><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.1pt">Background</span></span></span></span></b><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.1pt">: Magnetic nanoparticles attract increasing interest due to their use in cancer therapy and as drug carriers for several other diseases. The present study investigates the physiochemical properties of quercetin-conjugated superparamagnetic Fe3O4 nanoparticles and their effects on breast cancer cell line MCF-7. <b>Methods</b>:</span></span></span></span> <span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.1pt">A simple precipitation method was used to prepare the </span></span></span></span><span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.1pt">Poly Ethylene Imine (PEI)-coated Fe3O4 nanoparticles; they were then conjugated with flavonoid-compound quercetin on the surface via carboxylic/amine group using nanoprecipitation method. Then, the physical and chemical parameters were calculated using Zeta-sizer, scanning electron microscopy (SEM), and extract release patterns at 37 and 42 ⁰C. Finally, the toxicity level of this quercetin- conjugated nanosystem on the MCF-7 cells was investigated by MTT assay. <b>Results</b>: The results showed that the prepared nanosystem attained about 74% of quercetin inclusion, 91.2 nm size, 65.1 mV zeta potential, spherical morphology and a controlled release. Compared to Fe3O4 nanoparticles and pure quercetin, MTT and microscopy analysis revealed that quercetin-conjugated Fe3O4 nanoparticles induced considerable cytotoxicity, and morphology changes against MCF7 cells. <b><span style="color:black">Conclusion</span></b><span style="color:black">: </span>Quercetin-conjugated Fe3O4 nanoparticles have appropriate physiochemical properties; they can be a suitable carrier for drug delivery and a promising therapy for candidates.</span></span></span></span><br> Corresponding Author:</span></span></span><b><span style="font-size:10.0pt"><span style="line-height:115%"><span bold="" new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.2pt">Bibi Fatemeh Haghiralsadat</span></span></span></span></b><br> <span style="font-size:11pt"><span style="line-height:115%"><span calibri="" style="font-family:"><a href="https://orcid.org/0000-0002-8655-2118" style="color:blue; text-decoration:underline">View Orcid in Profile</a><br> You can search for this author in <a href="https://(Bibi Fatemeh Haghiralsadat[Author]) AND (Shahid Sadoughi University of Medical Sciences[Author])" style="color:blue; text-decoration:underline">PubMed</a>&nbsp;&nbsp;&nbsp;<a href="https://scholar.google.com/citations?user=C7tUpVwAAAAJ&hl=en&oi=ao">&nbsp; Google Scholar Profile</a></span></span></span></div> <br> &nbsp; Nanoparticles, Quercetin, Fe3O4, Breast cancer 565 576 http://jnfs.ssu.ac.ir/browse.php?a_code=A-10-360-3&slc_lang=en&sid=1 Fateme Sadeghi Nodoushan 0000-0003-4461-3100 No Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Fatemeh Hakimian 0000-0003-1080-4523 No Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran Bibi Fatemeh Haghiralsadat 0000-0002-8655-2118 Yes Department of Advanced Medical Sciences and Technologies, School of Paramedicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Sana Taghiyar 0000-0003-0121-8696 No Department of Clinical Biochemistry, International Campus, Shahid Sadoughi University of Medical Science, Yazd, Iran