en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">Our aims were</span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">to prepare microspheres labelled with radioactive astatine as brachytherapy seeds and to confirm the antitumor ability of these microspheres.</span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-GB">Materials and Methods</span></span></span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-GB">:</span></span></span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">Chitosan-collagen composite microspheres (CCMs) were synthesized through an emulsification crosslink reaction and radiolabelled with </span></span></span><span lang="en-GB" style="font-size:5.9939pt"><span style="font-family:Calibri"><span style="language:en-GB">²¹¹</span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">At using the chloramine-T method. Radiation stability was assessed in both</span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">phosphate-buffered saline and blood serum. The in vivo distribution and therapeutic effects were evaluated in BALB/c nude mice with implanted tumours.</span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-GB">Results</span></span></span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-GB">:</span></span></span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">CCMs showed ideal morphological characteristics (diameter of 7.5-15 &mu;m) and acceptable radiation stability (73.99% in PBS and 72.56% in serum after 16 hours). The in vivo biodistribution analysis demonstrated that </span></span></span><span lang="en-GB" style="font-size:5.9939pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">²¹¹</span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">At-CCMs were highly localized in tumour tissue. The therapeutic efficacy of </span></span></span></span><span lang="en-GB" style="font-size:5.9939pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">²¹¹</span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">At-CCMs when intratumorally injected into a cervical tumour model was assessed. Fourteen days after a single-dose treatment with </span></span></span></span><span lang="en-GB" style="font-size:5.9939pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">²¹¹</span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">At-CCMs, significantly retarded tumour volume growth was observed.</span></span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-GB">Conclusion</span></span></span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-GB">:</span></span></span></span></span> <span lang="en-GB" style="font-size:5.9939pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">²¹¹</span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">At-</span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">CCM brachytherapy has the potential </span></span></span></span><span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-GB">to provide an alternative solution for tumour treatment.</span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Tahoma"><span style="font-style:italic"><span style="language:en-US"></span></span></span></span></span></span></span></span></span></span></div> <span style="font-size:10pt"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black">&nbsp;</span></span></span></span><br> &nbsp; Brachytherapy, microspheres, radiation oncology, Astatine-211. 793 798 http://ijrr.com/browse.php?a_code=A-10-1-980&slc_lang=en&sid=1 Y. Li 7900319475328460022584 7900319475328460022584 No Department of Nuclear Medicine, West China Hospital of Sichuan University, China F. Pang 7900319475328460022585 7900319475328460022585 No Department of Intervention, Shenzhen Traditional Chinese Medicine Hospital, China H. Cai 7900319475328460022586 7900319475328460022586 No Department of Nuclear Medicine, West China Hospital of Sichuan University, China L. Li tsflyh@126.com 7900319475328460022587 7900319475328460022587 Yes Department of Nuclear Medicine, West China Hospital of Sichuan University, China