A Full Set of In Vitro Assays in Chitosan/Tween 80 Microspheres Loaded with Magnetite Nanoparticles

Glycyrrhizic Acid Formulated in Hydrotalcite Nanocarriers Intended to Act as a Hepatoprotective Agent

The article focuses on preparing a nanoformulation based on hydrotalcite and glycyrrhizic acid (GA), seeking a hepatoprotective effect. For this purpose, hydrotalcite-GA formulations were prepared by varying the following conditions to obtain optimal systems in terms of size and PDI (the lowest values), and Z potential (the highest values): (i) type of hydrotalcite (obtained by co-precipitation or calcined hydrotalcite); method used (ultrasound or high shear stirring), and (iii) type of stabilizer (Tween®80 or Pluronic® F-127). The best results were obtained using hydrotalcite obtained by co-precipitation, with high shear stirring and adding a stabilizer, either Tween®80 (HT-T80-GA: mean particle size = 315 nm, PDI = 0.18, Z potential = -20.93) or Pluronic® F-127 (HT-PF127-GA: mean particle size = 307 nm; PDI = 0.27, Z potential = -21.03). After stability studies, the HT-T80-GA formulation was chosen to study antioxidant activity, cytotoxicity, and intracellular penetration capacity. Although the hepatoprotective effect of GA in solution allowed a high viability and antioxidant activity, the fact of including GA in the HT-T80-GA formulation favored its penetration into hepatocytes, with a decrease in Caspase-3/7 expression of C-9 hepatocyte cells treated with H2O2, suggesting the capacity to inhibit apoptosis.

Protective Encapsulation of a Bioactive Compound in Starch-Polyethylene Glycol-Modified Microparticles: Degradation Analysis with Enzymes

Starch is a promising polymer for creating novel microparticulate systems with superior biocompatibility and controlled drug delivery capabilities. In this study, we synthesized polyethylene glycol (PEG)-modified starch microparticles and encapsulated folic acid using a solvent-mediated acid-base precipitation method with magnetic stirring, which is a simple and effective method. To evaluate particle degradation, we simulated physiological conditions by employing an enzymatic degradation approach. Our results with FTIR and SEM confirmed the successful synthesis of starch-PEG microparticles encapsulating folic acid. The average size of starch microparticles encapsulating folic acid was 4.97 μm and increased to 6.01 μm upon modification with PEG. The microparticles were first exposed to amylase at pH 6.7 and pepsin at pH 1.5 at different incubation times at physiological temperature with shaking. Post-degradation analysis revealed changes in particle size and morphology, indicating effective enzymatic degradation. FTIR spectroscopy was used to assess the chemical composition before and after degradation. The initial FTIR spectra displayed characteristic peaks of starch, PEG, and folic acid, which showed decreased intensities after enzymatic degradation, suggesting alterations in chemical composition. These findings demonstrate the ongoing development of starch-PEG microparticles for controlled drug delivery and other biomedical applications and provide the basis for further exploration of PEG-starch as a versatile biomaterial for encapsulating bioactive compounds.

Enrichment of phosphopeptides by arginine-functionalized magnetic chitosan nanoparticles

One of the most crucial and prevalent post-translational modifications is the phosphorylation of proteins. The study and examination of protein phosphorylation hold immense importance in comprehending disease mechanisms and discovering novel biomarkers. However, the inherent low abundance, low ionization efficiency, and coexistence with non phosphopeptides seriously affect the direct analysis of phosphopeptides by mass spectrometry. In order to tackle these problems, it is necessary to carry out selective enrichment of phosphopeptides prior to conducting mass spectrometry analysis. Herein, magnetic chitosan nanoparticles were developed by incorporating arginine, and were then utilized for phosphopeptide enrichment. A tryptic digest of β-casein was chosen as the standard substance. After enrichment, combined with matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS), the detection limit of the method was 0.4 fmol. The synthesized magnetic material demonstrated great potential in the detection of phosphopeptides in complex samples, as proven by its successful application in detecting phosphopeptides in skim milk and human saliva samples.

Green Synthesis of Mesquite-Gum-Stabilized Gold Nanoparticles for Biomedical Applications: Physicochemical Properties and Biocompatibility Assessment

Using cytotoxic reducing and stabilizing agents in the synthesis of gold nanoparticles (AuNPs) limits their use in biomedical applications. One strategy to overcome this problem is using "green" synthesis methodologies using polysaccharides. In the present study, we propose a green methodology for synthetizing AuNPs with mesquite gum (MG) as a reducing agent and steric stabilizer in Gold(III) chloride trihydrate aqueous solutions to obtain biocompatible nanoparticles that can be used for biomedical applications. Through this method, AuNPs can be produced without using elevated temperatures or pressures. For synthetizing gold nanoparticles coated with mesquite gum (AuNPs@MG), Gold(III) chloride trihydrate was used as a precursor, and mesquite gum was used as a stabilizing and reducing agent. The AuNPs obtained were characterized using UV-Vis spectroscopy, dynamic light scattering, transmission electron microscopy, scanning transmission electron microscopy, and FT-IR spectroscopy. The stability in biological media (phosphate buffer solution), cytotoxicity (MTT assay, hematoxylin, and eosin staining), and hemocompatibility (Hemolysis assay) were measured at different concentrations and exposure times. The results showed the successful synthesis of AuNPs@MG with sizes ranging from 3 to 30 nm and a zeta potential of -31 mV. The AuNPs@MG showed good colloidal stability in PBS (pH 7.4) for up to 24 h. Finally, cytotoxicity assays showed no changes in cell metabolism or cell morphology. These results suggest that these gold nanoparticles have potential biomedical applications because of their low cytotoxicity and hemotoxicity and improved stability at a physiological pH.

An exhaustive scrutiny to amplify the heating prospects by devising a core@shell nanostructure for constructive magnetic hyperthermia applications

An interfacial integration at the nanoscale domain through a core@shell (CS) nanostructure has constructively unbarred a wide dimension to researchers on biomedical applications, especially for magnetic fluid hyperthermia. Lately, the interconnection of the exchange bias effect (EBE) through the interface coupling to the magnetic heating efficiency has uttered its utmost prominence for researchers. Here, we delineate the ascendency of the heating ability through a coalescing assembly of mixed ferrite Co0.5Zn0.5 Fe2O4 (CZ) and soft magnetic material Fe3O4 (F), by devising a network of CoZnFe2O4@Fe3O4 (CZF) CS nanostructure. A hefty interface activity with validation of the EBE phenomenon is divulged through magnetic scrutiny for the CS sample. The magnetic nanoparticles heating response to applied magnetic field and frequency is discerned at three distinct fields, where the outcome prevailed to inflated specific loss power for CS CZF in distinction to bare F and CZ samples for all the assessments. Remarkably; a lofty intrinsic loss parameter is also perceived for the CS sample recorded to about 5.36 nHm2 g-1; which is another eccentric outcome that significantly labels the CS CZF sample as a potentially high heating competence agent. This comprehension accords to a finer perspective to meliorate the theranostic environment for hyperthermia applications.

Carboxymethylated Gums and Derivatization: Strategies and Significance in Drug Delivery and Tissue Engineering

Natural polysaccharides have been widely exploited in drug delivery and tissue engineering research. They exhibit excellent biocompatibility and fewer adverse effects; however, it is challenging to assess their bioactivities to that of manufactured synthetics because of their intrinsic physicochemical characteristics. Studies showed that the carboxymethylation of polysaccharides considerably increases the aqueous solubility and bioactivities of inherent polysaccharides and offers structural diversity, but it also has some limitations that can be resolved by derivatization or the grafting of carboxymethylated gums. The swelling ratio, flocculation capacity, viscosity, partition coefficient, metal absorption properties, and thermosensitivity of natural polysaccharides have been improved as a result of these changes. In order to create better and functionally enhanced polysaccharides, researchers have modified the structures and properties of carboxymethylated gums. This review summarizes the various ways of modifying carboxymethylated gums, explores the impact that molecular modifications have on their physicochemical characteristics and bioactivities, and sheds light on various applications for the derivatives of carboxymethylated polysaccharides.

Chitosan-sialic acid nanoparticles of selenium: Statistical optimization of production, characterization, and assessment of cytotoxic effects against two human glioblastoma cell lines

According to the favorable antitumor properties of selenium, this study aimed to design a novel form of selenium nanoparticles (Se NPs) functionalized with chitosan (Cs) and sialic acid to assess their antitumor effects on the human glioblastoma cell lines (T98 and A172). Se NPs were synthesized in the presence of chitosan and ascorbic acid (Vc) and the synthesis conditions were optimized using response surface methodology. Se NPs@Cs were obtained with a monoclinic structure with an average diameter of 23 nm under the optimum conditions (reaction time = 30 min, chitosan concentration = 1 % w/v, Vc/Se molar ratio = 5). To modify Se NP@Cs for glioblastoma treatment, sialic acid was used to cover the surface of the NPs. Sialic acid was successfully attached to the surface of Se NPs@Cs, and Se NPs@Cs-sialic acid were formed in the size range of 15-28 nm. Se NPs@Cs-sialic acid were stable for approximately 60 days at 4 ℃. The as-synthesized NPs exerted inhibitory effects on T98 greater than 3 T3 > A172 cells in a dose- and time-dependent manner. Additionally, sialic acid ameliorated the blood biocompatibility of Se NPs@Cs. Taken together, sialic acid improved both the stability and biological activity of Se NPs@Cs.

New potential application of hydroxypropyl-β-cyclodextrin in solid self-nanoemulsifying drug delivery system and solid dispersion

The purpose of this study was to use hydroxypropyl-β-cyclodextrin (HP-β-CD) as a novel carrier in solid SNEDDS and solid dispersions to enhance the solubility and oral bioavailability of poorly water-soluble dexibuprofen. The novel dexibuprofen-loaded solid SNEDDS was composed of dexibuprofen, corn oil, polysorbate 80, Cremophor® EL, and HP-β-CD at a weight ratio of 45/35/50/15/100. This solid SNEDDS spontaneously formed a nano-emulsion with a size of approximately 120 nm. Unlike the conventional solid SNEDDS prepared with colloidal silica as a carrier, this dexibuprofen-loaded solid SNEDDS exhibited a spherical structure. Similar to the dexibuprofen-loaded solid dispersion prepared with HP-β-CD, the transformation of the crystalline drug to an amorphous state with no molecular interactions were observed in the solid SNEDDS. Compared to the solid dispersion and dexibuprofen powder, solid SNEDDS significantly enhanced drug solubility and AUC. Therefore, HP-β-CD is a novel potential carrier in SNEDDS for improving the oral bioavailability of dexibuprofen.

Modification of Branched Polyethyleneimine Using Mesquite Gum for Its Improved Hemocompatibility

In the present study, the modification of branched polyethyleneimine (b-PEI) was carried out using mesquite gum (MG) to improve its hemocompatibility to be used in biomedical applications. In the copolymer synthesis process (carboxymethylated mesquite gum grafted polyethyleneimine copolymer (CBX-MG-PEI), an MG carboxymethylation reaction was initially carried out (carboxymethylated mesquite gum (CBX-MG). Subsequently, the functionalization between CBX-MG and b-PEI was carried out using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as crosslinking agents. The synthesis products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Thermogravimetric analysis showed that CBX-MG and CBX-MG-PEI presented a lower decomposition temperature than MG. The CBX-MG-PEI has a high buffer capacity in the pH range of 4 to 7, similar to the b-PEI. In addition, the CBX-MG-PEI showed an improvement in hemocompatibility in comparison with the b-PEI. The results showed a non-hemolytic property at doses lower than 0.1 µg/mL (CBX-MG-PEI). These results allow us to propose that this copolymer be used in transfection, polymeric nanoparticles, and biomaterials due to its physicochemical and hemocompatibility properties.