RESUMO
Nanotechnology is the science of creating materials at the nanoscale by using various devices, structures, and systems that are often inspired by nature. Micro- and nanoparticles (MPs, NPs) are examples of such materials that have unique properties and can be used as carriers for delivering drugs for different biomedical applications. Chitosan (CS) is a natural polysaccharide that has been widely studied, but it has a problem with low water solubility at neutral or basic pH, which limits its processability. The goal of this work was to use a chemically modified CS with poly(ethylene glycol) methyl ether acrylate (PEGA) to prepare CS micronic and submicronic particles (MPs/NPs) that can deliver different types of antibiotics, respectively, levofloxacin (LEV) and Ciprofloxacin (CIP). The particle preparation procedure employed a double crosslinking method, ionic followed by a covalent, in a water/oil emulsion. The studied process parameters were the precursor concentration, stirring speeds, and amount of ionic crosslinking agent. MPs/NPs were characterized by FT-IR, SEM, light scattering granulometry, and Zeta potential. MPs/NPs were also tested for their water uptake capacity in acidic and neutral pH conditions, and the results showed that they had a pH-dependent behavior. The MPs/NPs were then used to encapsulate two separate drugs, LEV and CIP, and they showed excellent drug loading and release capacity. The MPs/NPs were also found to be safe for cells and blood, which demonstrated their potential as suitable drug delivery systems for biomedical applications.
RESUMO
Nowadays, the Magnetically Targeted Drug Delivery System (MTDDS) is among the most attractive and promising strategies for delivering drugs to the target site. The present study aimed to obtain a biopolymer-magnetite-drug nanosystem via a double crosslinking (ionic and covalent) technique in reverse emulsion, which ensures the mechanical stability of the polymer support in the form of original hybrid nanospheres (NSMs) loaded with biologically active principles (the 5-Fluorouracil (5-FU)) as a potential treatment for cancer. Obtained NSMs were characterized in terms of structure (FT-IR), size (DLS), morphology (SEM), swelling, and 5-FU entrapment/release properties, which were dependent on the synthesis parameters (polymer concentration, dispersion speed, and amount of ionic crosslinking agent). SEM analysis results revealed that NSMs presented a spherical shape and are homogeneous and separated. Moreover, NSMs' ability to load/release 5-FU was tested in vitro, the results confirming, as expected, their dependence on the varied synthesis process and NSM swelling ability in physiological liquids. The drug transport mechanism through the polymer matrix of its release is the Fickian type. The morphological, bio-material characteristics and the ability to include and release an antitumor drug highlight the utility of the NSMs obtained for targeting and treating some tumor diseases.
RESUMO
Chitosan (CS) crosslinking has been thoroughly investigated, but the chemical reactions leading to submicronic hydrogel formulations pose problems due to various physical/chemical interactions that limit chitosan processability. The current study employs the chemical modification of chitosan by Michael addition of poly (ethylene glycol) methyl ether acrylate (PEGA) to the amine groups to further prepare chitosan particulate hydrogels (CPH). Thus, modified CS is subjected to a double crosslinking, ionic and covalent, in water/oil emulsion. The studied process parameters are polymer concentration, stirring speed, and quantity of ionic crosslinker. The CPH were structurally and morphologically characterized through infrared spectroscopy, scanning electron microscopy, light scattering granulometry, and zeta potential, showing that modified CS allows better control of dimensional properties and morphology as compared with neat CS. Swelling properties were studied in acidic and neutral pH conditions, showing that pH-dependent behavior was maintained after grafting and double crosslinking. The applicability of the prepared materials was further tested for drug loading and in vitro delivery of levofloxacin (LEV), showing excellent capacity. CPH were found to be cyto- and hemocompatible demonstrating their potential for effective use as a controlled release system for different biomedical applications.
