Designing of spherical chitosan nano-shells with micellar cores for solvation and safeguarded delivery of strongly lipophilic drugs

Ultrasound-assisted synthesis of MIL-88(Fe) conjugated starch-Fe3O4 nanocomposite: A safe antibacterial carrier for controlled release of tetracycline

A constructing antibiotic carrier with a sustained release profile is a promising method to stop long-term bacterial infection, which is of ideal interest in different biomedical fields. To end this, the present study aims to design a novel carrier based on the modification of biopolymeric starch for the rising possible interaction between carrier and antibiotic agent. We established an in-situ ultrasound-assisted method was applied to grow and create MIL-88(Fe) framework in the structure of magnetic polysaccharide (i.e., St/Fe₃O₄) synthesized by precipitation method resulting in St/Fe₃O₄/MIL-88(Fe) nanocomposite. It was loaded with a high amount of Tetracycline (TC) through its immersion into the TC aqueous solution. The release profile of TC-loaded St/Fe₃O₄/MIL-88(Fe) displays a lower initial burst release (about 26 % after 12 h) and followed by a controlled and sustained release (about 73 % up to 168 h) in the simulated physiological environment at pH 7.4. The in vitro cytotoxicity showed good cytocompatibility against Human skin fibroblast (HFF-1) cells. TC-loaded St/Fe₃O₄/MIL-88(Fe) showed higher antibacterial activity against both S. aureus and E. coli with the MIC value of 64 and 128 μg·mL^-1, respectively.

CDX-modified chitosan nanoparticles remarkably reduce therapeutic dose of fingolimod in the EAE model of mice

Fingolimod (Fin), an FDA-approved drug, is used to control relapsing-remitting multiple sclerosis (MS). This therapeutic agent faces crucial drawbacks like poor bioavailability rate, risk of cardiotoxicity, potent immunosuppressive effects, and high cost. Here, we aimed to assess the therapeutic efficacy of nano-formulated Fin in a mouse model of experimental autoimmune encephalomyelitis (EAE). Results showed the suitability of the present protocol in the synthesis of Fin-loaded CDX-modified chitosan (CS) nanoparticles (NPs) (Fin@CSCDX) with suitable physicochemical features. Confocal microscopy confirmed the appropriate accumulation of synthesized NPs within the brain parenchyma. Compared to the control EAE mice, INF-γ levels were significantly reduced in the group that received Fin@CSCDX (p < 0.05). Along with these data, Fin@CSCDX reduced the expression of TBX21, GATA3, FOXP3, and Rorc associated with the auto-reactivation of T cells (p < 0.05). Histological examination indicated a low-rate lymphocyte infiltration into the spinal cord parenchyma after the administration of Fin@CSCDX. Of note, HPLC data revealed that the concentration of nano-formulated Fin was about 15-fold less than Fin therapeutic doses (TD) with similar reparative effects. Neurological scores were similar in both groups that received nano-formulated fingolimod 1/15th of free Fin therapeutic amounts. Fluorescence imaging indicated that macrophages and especially microglia can efficiently uptake Fin@CSCDX NPs, leading to the regulation of pro-inflammatory responses. Taken together, current results indicated that CDX-modified CS NPs provide a suitable platform not only for the efficient reduction of Fin TD but also these NPs can target the brain immune cells during neurodegenerative disorders.

Biologically Relevant Micellar Nanocarrier Systems for Drug Encapsulation and Functionalization of Metallic Nanoparticles

The preparation of new and functional nanostructures has received more attention in the scientific community in the past decade due to their wide application versatility. Among these nanostructures, micelles appear to be one of the most interesting supramolecular organizations for biomedical applications because of their ease of synthesis and reproducibility and their biocompatibility since they present an organization similar to the cell membrane. In this work, we developed micellar nanocarrier systems from surfactant molecules derived from oleic acid and tetraethylene glycol that were able to encapsulate and in vitro release the drug dexamethasone. In addition, the designed micelle precursors were able to functionalize metallic NPs, such as gold NPs and iron oxide NPs, resulting in monodispersed hybrid nanomaterials with high stability in aqueous media. Therefore, a new triazole-derived micelle precursor was developed as a versatile encapsulation system, opening the way for the preparation of new micellar nanocarrier platforms for drug delivery, magnetic resonance imaging, or computed tomography contrast agents for therapeutic and diagnostic applications.

Facile synthesis of Zn-based metal-organic framework in the presence of carboxymethyl cellulose: A safe carrier for ibuprofen

Fabrication of porous materials with a high surface area affords a great interest to achieve a system with a prolonged drug release manner. In this context, the subject of this work is to describe a novel green one-pot synthesis route for the growth of metal-organic framework (MOF) from zinc metal (Zn) and 1, 4-benzene dicarboxylic acid (BDC) in the vicinity of the carboxymethyl cellulose (CMC), which homogeneously confined in the biopolymeric chains. The synthesized Zn (BDC)@CMC was characterized and confirmed using different analyses. N₂ adsorption/desorption isotherms determined the mean diameter of pore size of about 2.3993 nm. Ibuprofen (IBU) as a model drug was highly loaded to the Zn(BDC)@CMC by immersing in the drug solution; 50.95%. The in vitro IBU release study indicated that the Zn(BDC)@CMC has more attractive performances than pristine Zn(BDC). The IBU release occurred via the Fickian mechanism. Isotherm studies showed that the IBU adsorption on obeys from Langmuir isotherm; R² 0.9623. The MTT results revealed the HEK 293A cell viability of higher than 90% for Zn(BDC)@CMC that confirms its cytocompatibility. Overall, obtained results confirm the functionality of CMC biopolymer for in situ growth of MOF in the presence of it due to having the reactive nature.

Ultrasound-assisted synthesis of MIL-88(Fe) coordinated to carboxymethyl cellulose fibers: A safe carrier for highly sustained release of tetracycline

For stopping long-time harmful bacterial infection, designing a drug carrier with a highly prolonged release profile is a promising approach that is of interest to different biomedical areas. The subject of this work is to synthesis a novel carrier system through coordination of MIL-88(Fe) to carboxymethyl cellulose (CMC) for enhancing interaction between drug and carrier. We established an ultrasound-assisted synthetic method for in situ synthesis of MIL-88(Fe) in the presence of CMC resulting in CMC/MIL-88(Fe) composite. The CMC/MIL-88(Fe) was loaded with a high amount of Tetracycline (TC) by immersion of carrier to the TC aqueous solution. The release profile in the simulated physiological conditions, pH 7.4, revealed a low initial burst release followed by a sustained and prolonged release over 384 h. The in vitro cytotoxicity of CMC/MIL-88(Fe) against Human skin fibroblast (HFF-1) cells was calculated by MTT assay and showed a good cytocompatibility. The antibacterial activity was found for TC-loaded CMC/MIL-88(Fe) toward both E. coli and S. aureus with MIC 64 mg·ml^-1.

Preparation and characterization of a Schiff-based chitosan-fructose quaternary ammonium salt for medical applications

The aim of this study was to develop a new chitosan derivative and investigate its effects on fresh tissue healing in rats. A chitosan-fructose Schiff based quaternary ammonium salt (CS = Fru-DEAE) was synthesized for the first time and characterized using FT-IR and ¹HNMR, and the modification rate and the solution properties were studied. A rat wound model was established, and the experimental group was treated using 0.1 g of the chitosan derivative hydrogel. The wound healing rate, and the concentration of collagen III and proline in the wounds were assessed in the experimental group and compared with those of the control group at 7, 10, and 15 d. The CS = Fru-DEAE hydrogel demonstrated good performance and promoted the healing of infected wounds in rats. The hydrogel could accelerate the infiltration of inflammatory cells and increase the amount of type III collagen in the wound area, which likely contributed to its efficacy.