{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T05:18:44Z","timestamp":1787635124851,"version":"build-2736575974"},"reference-count":35,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFD1800902"],"award-info":[{"award-number":["2023YFD1800902"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"<jats:p>\n                    Bovine endometritis is a major reproductive disorder in cattle that reduces fertility, prolongs calving intervals, and decreases productivity in the livestock industry. However, limitations in current therapeutic approaches underscore the need for novel and more effective therapeutic formulations. This study aimed to develop an enrofloxacin suspension-based thermosensitive hydrogel intrauterine infusion (Enro-TSH). We utilized 16% Poloxamer 407 and 0.5% Poloxamer 188 as the gel matrix and Carbopol 941 as the suspending agent. We screened formulations with Carbopol 941 contents of 0.00%\u22120.14% by characterizing their rheological properties, sedimentation volume ratio,\n                    <jats:italic>in vitro<\/jats:italic>\n                    release profiles and microstructures, and identified 0.08% as the optimal Carbopol concentration. The optimally screened formulation Enro-TSH-Car8 showed viscosities (\u03b7) of 6.04 \u00b1 0.59 Pa\u00b7s at 4\u00b0C, 7.22 \u00b1 0.31 Pa\u00b7s at 25\u00b0C, and 785 \u00b1 42.46 Pa\u00b7s at 38.5\u00b0C, with a gelation temperature of 35.60 \u00b1 0.75\u00b0C and gelation time of 123 \u00b1 8 s. We then conducted\n                    <jats:italic>in vitro<\/jats:italic>\n                    release studies using 0.9% sodium chloride solution as the medium, and obtained cumulative release rates of 48.73 \u00b1 2.61% at 12 h and 94.1 \u00b1 3.89% at 24 h. Specifically, the cumulative release profile from 1 to 24 h closely fitted a zero-order kinetic equation (\n                    <jats:italic>R<\/jats:italic>\n                    <jats:sup>2<\/jats:sup>\n                    = 0.991). Drug release from 1 to 6 h adhered to the Ritger-Peppas model (\n                    <jats:italic>R<\/jats:italic>\n                    <jats:sup>2<\/jats:sup>\n                    = 0.992,\n                    <jats:italic>n<\/jats:italic>\n                    &amp;gt; 0.89), indicating a matrix erosion mechanism, whereas release from 6 to 24 h complied with the Higuchi model (\n                    <jats:italic>R<\/jats:italic>\n                    <jats:sup>2<\/jats:sup>\n                    = 0.999), suggesting a diffusion-driven mechanism. In addition, we characterized the freeze-dried formulation via scanning electron microscopy (SEM), and neither enrofloxacin nor Carbopol significantly affected the gel microstructure. Overall, this study successfully developed a thermosensitive intrauterine infusion loaded with suspended enrofloxacin particles for bovine endometritis. This novel integrated system unites thermo-responsive hydrogel and suspension formulation, adopting the lowest reported Poloxamer 407 content (16%) and an optimized Carbopol concentration to balance suspension stability and rheological properties. Meanwhile, the enrofloxacin-loaded formulation exhibits a mild pH value (7.0 \u00b1 0.2), providing a promising strategy for the treatment of bovine endometritis.\n                  <\/jats:p>","DOI":"10.3389\/fvets.2026.1876946","type":"journal-article","created":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T04:23:14Z","timestamp":1787631794000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Development of a thermosensitive enrofloxacin hydrogel suspension for intrauterine infusion in cattle"],"prefix":"10.3389","volume":"13","author":[{"given":"Jiajia","family":"Wang","sequence":"first","affiliation":[{"name":"National Feed Drug Reference Laboratories, Feed Research Institute, Chinese Academy of Agricultural Sciences","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaolei","family":"He","sequence":"additional","affiliation":[{"name":"National Feed Drug Reference Laboratories, Feed Research Institute, Chinese Academy of Agricultural Sciences","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lijiao","family":"Yang","sequence":"additional","affiliation":[{"name":"National Feed Drug Reference Laboratories, Feed Research Institute, Chinese Academy of Agricultural Sciences","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lanting","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Medical, Veterinary and Life Sciences, University of Glasgow","place":["Glasgow, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiubo","family":"Li","sequence":"additional","affiliation":[{"name":"National Feed Drug Reference Laboratories, Feed Research Institute, Chinese Academy of Agricultural Sciences","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fei","family":"Xu","sequence":"additional","affiliation":[{"name":"National Feed Drug Reference Laboratories, Feed Research Institute, Chinese Academy of Agricultural Sciences","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.anireprosci.2004.04.006","article-title":"Postpartum uterine health in cattle","author":"Sheldon","year":"2004","journal-title":"Anim Reprod Sci"},{"key":"B2","doi-asserted-by":"publisher","first-page":"1516","DOI":"10.1016\/j.theriogenology.2005.08.021","article-title":"Defining postpartum uterine disease in cattle","volume":"65","author":"Sheldon","year":"2006","journal-title":"Theriogenology"},{"key":"B3","doi-asserted-by":"publisher","first-page":"2408","DOI":"10.3168\/jds.2010-3697","article-title":"Short communication: Metritis affects milk production and cull rate of Holstein multiparous and primiparous dairy cows differently","volume":"94","author":"Wittrock","year":"2011","journal-title":"J Dairy Sci"},{"key":"B4","doi-asserted-by":"publisher","first-page":"926","DOI":"10.1292\/jvms.20-0165","article-title":"Intrauterine infusion of povidone-iodine: Its effect on the endometrium and subsequent fertility in postpartum dairy cows","volume":"82","author":"Yoshida","year":"2020","journal-title":"J Vet Med Sci"},{"key":"B5","doi-asserted-by":"publisher","first-page":"8314","DOI":"10.3168\/jds.2016-10959","article-title":"A study to examine the relationship between metritis severity and depletion of oxytetracycline in plasma and milk after intrauterine infusion","volume":"99","author":"Gorden","year":"2016","journal-title":"J Dairy Sci"},{"key":"B6","doi-asserted-by":"publisher","first-page":"172105250","DOI":"10.1016\/j.rvsc.2024.105250","article-title":"Comparison between intrauterine application of an antibiotic and an herbal product to treat clinical endometritis in dairy cattle - 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