Advances in surface design and biomedical applications of magnetic nanoparticles.

Despite significant efforts by scientists in the development of advanced nanotechnology materials for smart diagnosis devices and drug delivery systems, the success of clinical trials remains largely elusive. In order to address this biomedical challenge, magnetic nanoparticles (MNPs) have gained attention as a promising candidate due to their theranostic properties, which allow the simultaneous treatment and diagnosis of a disease. Moreover, MNPs have advantageous characteristics such as a larger surface area, high surface-to-volume ratio, enhanced mobility, mass transference and, more notably, easy manipulation under external magnetic fields. Besides, certain magnetic particle types based on the magnetite (Fe3O4) phase have already been FDA-approved, demonstrating biocompatible and low toxicity. Typically, surface modification and/or functional group conjugation are required to prevent oxidation and particle aggregation. A wide range of inorganic and organic molecules have been utilized to coat the surface of MNPs, including surfactants, antibodies, synthetic and natural polymers, silica, metals, and various other substances. Furthermore, various strategies have been developed for the synthesis and surface functionalization of MNPs to enhance their colloidal stability, biocompatibility, good response to an external magnetic field, etc. Both uncoated MNPs and those coated with inorganic and organic compounds exhibit versatility, making them suitable for a range of applications such as drug delivery systems (DDS), magnetic hyperthermia, fluorescent biological labels, biodetection and magnetic resonance imaging (MRI). Thus, this review provides an update of recently published MNPs works, providing a current discussion regarding their strategies of synthesis and surface modifications, biomedical applications, and perspectives.

Fast ultrasound assisted synthesis of chitosan-based magnetite nanocomposites as a modified electrode sensor.

Chitosan-based magnetite nanocomposites were synthesized using a versatile ultrasound assisted in situ method involving one quick step. This synthetic route approach results in the formation of spheroidal nanoparticles (Fe3O4) with average diameter between 10 and 24nm, which were found to be superparamagnetic with saturation magnetization (Ms) ranges from 32-57emug(-1), depending on the concentration. The incorporation of Fe3O4 into chitosan matrix was also confirmed by FTIR and TG techniques. This hybrid nanocomposite has the potential application as electrochemical sensors, since the electrochemical signal was excepitionally stable. In addition, the in situ strategy proposed in this work allowed us to synthesize the nanocomposite system in a short time, around 2min of time-consuming, showing great potential to replace convencional methods. Herein, the procedure will permit a further diversity of applications into nanocomposite materials engineering.

Analgesic and anti-inflammatory dose-response relationship of 7.5 and 15 mg meloxicam after lower third molar removal: a double-blind, randomized, crossover study.

Fifty patients were scheduled to undergo removal of symmetrically positioned lower third molars in two separate appointments. Meloxicam 7.5 or 15 mg was once daily administered in a double-blind, randomized and crossover manner after the surgery for 4 days. Objective and subjective parameters were recorded for comparison of postoperative courses. Patients treated with 7.5mg meloxicam who underwent osteotomy reported higher pain scores at 1.5, 3, 4, 10, 12 and 16 h (P<0.05) and ingested a greater amount of rescue analgesic medication (P<0.05) than those who did not require osteotomy. A higher percentage of patients who underwent osteotomy medicated with 7.5mg meloxicam needed rescue medication as compared to those who did not require osteotomy (P<0.05). There was a similar mouth opening at suture removal compared with preoperative values for both doses (P>0.05). There were no significant differences concerning swelling observed on the 2nd or 7th postoperative days in comparison with baseline (P>0.05) between the two doses. Pain, trismus and swelling after lower third molar removal not requiring osteotomy can be successfully controlled by a dose regimen of 7.5mg meloxicam once daily. For more aggressive extractions 15 mg meloxicam is advisable.