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Iron oxide nanoparticles (IONPs) have been identified as a promising class of compounds that can enhance contrast in MRI (magnetic resonance imaging) scans due to their superparamagnetic properties. This study evaluates the efficacy of dextran-coated IONPs as T2 contrast agents for MRI in a rabbit model. IONPs were prepared through a co-precipitation process and subsequently coated with a layer of dextran. The nanoparticles underwent characterization using techniques such as TEM (transmission electron microscopy), vibrating sample magnetometry (VSM), and XRD (X-ray diffraction). New Zealand White rabbits (n=6) were used for in vivo MRI studies. IONPs (10 mg Fe/kg) were administered intravenously, and MRI scans (T1- and T2-weighted) were taken at baseline and at various intervals (1, 4, and 24 h) after IONP administration. Signal intensity changes and contrast enhancement were analyzed in the liver, spleen, and kidneys. The IONPs exhibited an average size of 15 ± 3 nm, an inverse spinel crystal structure, and displayed magnetic characteristics indicative of superparamagnetism with a 65 ± 5 emu/g saturation magnetization. MRI scans revealed significant signal intensity changes and contrast enhancement in the liver, spleen, and kidneys after IONP administration. The maximum contrast enhancement was observed at 4 h post-injection, with a 60 ± 8% reduction in T2 signal intensity in the liver and a 45 ± 7% reduction in the spleen. The contrast enhancement persisted up to 24 h in the liver and spleen, while the kidneys showed lower contrast enhancement and rapid clearance of the nanoparticles. In conclusion, dextran-coated IONPs demonstrated effective T2 contrast enhancement in MRI of rabbits, particularly in the liver and spleen. The prolonged retention of the nanoparticles in these organs makes them suitable for long-term imaging studies. However, the rapid clearance from the kidneys may limit their application for kidney imaging. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been explored for their antimicrobial properties and potential in wound healing applications. This study investigates the effect of AgNPs on wound healing in a rabbit model. AgNPs were synthesized using a green synthesis approach and characterized by TEM and UV-Vis spectroscopy. Excisional wounds penetrating through the full depth of the skin were surgically induced on the ear of 15 New Zealand White rabbits. The specimens were categorized into 3 groups: control (saline), AgNP-low (0.1 mg/mL), and AgNP-high (1 mg/mL). Wound dressings containing the respective treatments were applied daily. The dimensions of the wounds were assessed at four time points: immediately after wound creation (day 0) and on the 3rd, 7th, and 14th days post-injury. Histological analysis and immunohistochemical staining for collagen I and III were performed on wound tissue samples. AgNPs were successfully synthesized, with an average size of 15 nm. Wound closure in the groups treated with AgNP was noticeably quicker when contrasted with the control group. On day 14, the AgNP-high group showed the highest percentage of wound closure (95.2±2.1%), followed by the AgNP-low group (88.7±3.5%) and control (76.4±4.2%). Histological analysis revealed enhanced reepithelialization, collagen deposition, and neovascularization in the AgNP-treated groups. Immunohistochemical staining demonstrated increased manifestation of collagen I and III in the AgNP groups. The use of AgNPs in a rabbit wound healing model demonstrated significant improvements across multiple parameters, including expedited wound closure, more efficient re-epithelialization, and a notable increase in collagen synthesis and deposition. This evidence implies that AgNPs have the potential to be used as a medicinal aid for enhanced wound healing. Additional research is required to clarify the fundamental processes and optimize the AgNP formulation for clinical applications. [ABSTRACT FROM AUTHOR]