Optimization of gemifloxacin loading and releasing by easy separable magnetic iron oxide nanoparticles modified with 3-aminopropyltriethoxysilane

In this project, the loading and release of the antibiotic gemifloxacin onto the surface of Fe 3 O 4 modified with 3-aminopropyltriethoxysilane (Fe 3 O 4 /APTES) adsorbent was investigated. The co-precipitation method was used to synthesize magnetic iron oxide nanoparticles. The Fe₃O₄ surface modified with 3-aminopropyltriethoxysilane was examined and characterized by XRD, TGA, SEM, and FT-IR analyses. Distinct absorption bands attributed to Fe 3 O 4 surface modified with 3-aminopropyltriethoxysilane were discerned in the FT-IR spectra of the adsorbent, both before and after the loading of the samples. In the XRD test, the crystallites were determined to be 20–35 nm in size. In electron microscope images, quasi-cubic nanoparticles were observed; subsequently, the loading and release of the drug gemifloxacin were performed on the adsorbents. The drug's absorption spectrum was recorded by UV–Vis spectrophotometry before and after loading the drug onto the adsorbents. The absorbance at the peak absorption wavelength of 282 nm was used to quantify the amount of drug loaded. Using the response surface method (RSM), the optimal values of 4 parameters affecting the loading process and three parameters affecting the release process were investigated. The four loading parameters included: drug concentration, amount of adsorbent, solution pH, and contact time, and the three release parameters included: amount of adsorbent loaded with Gemi drug, pH, and time. Meanwhile, pH had a significant role in drug release. The optimum values obtained in these processes by the RSM method were as follows: the highest amounts of Fe 3 O 4 and Fe 3 O 4 surface-modified with 3-aminopropyltriethoxysilane adsorbents were 859 and 642 mg/g (drug/mg adsorbent), respectively. The maximum total release of gemifloxacin was observed with the desired adsorbents. The highest release amount of gemifloxacin for Fe 3 O 4 and Fe 3 O 4 surface-modified with 3-aminopropyltriethoxysilane was 541 and 267 mg/g, respectively (in mg drug/g adsorbent). Also, the best release was obtained in terms of grams of drug per gram of adsorbent. We hope that this achievement will lay the foundation for the next generation of targeted antibiotic drug-delivery systems and, in the near future, make antibiotic treatments more precise and less invasive, helping to address the problem of antibiotic resistance.