Novel Flaxseed Gum Nanocomposites Are Slow Release Iron Supplements

Preparation of pH-responsive magnetic nanocomposite hydrogels based on k-carrageenan/chitosan/silver nanoparticles: Antibacterial carrier for potential targeted anticancer drug delivery

This study reports the development of new pH-responsive drug delivery systems that are important for the treatment of cancer. The Mentha plant extract was obtained and then used for the biosynthesis of magnetic Ag bio nanoparticles (M-Ag bio-NPs). They were added in the formulation of hybrid hydrogel of k-carrageenan (k-Cr) and chitosan (CS) toward the synthesis of magnetic nanocomposite hydrogels. Their chemical structure and morphology were characterized by different analyses. Doxorubicin (DOX) was used as a model anticancer drug to study the targeted drug release behavior of the synthesized nanocomposite hydrogels (loading capacity: about 98 %). In vitro drug release studies showed that the release profile was noticeably controlled in a pH-dependent manner (higher drug release at pH 5). The antibacterial assessment confirmed the high antibacterial activity for the synthesized hydrogel against S. aureus (MIC values 39.06 μg/mL) and E. coli (MIC values > 19.53). In-vitro cytotoxicity results (MTT assay) demonstrated good biocompatibility (higher than 88 %) for the blank nanocomposite hydrogels, while DOX-loaded nanocomposite hydrogels showed high toxicity (about 22 % in the concentration of 20 μg/mL) against HeLa cells. The results showed that the present nanocomposite hydrogels can be suggested for potential application as an antibacterial and anticancer carrier.

Nano-Sized Antioxidative Trimetallic Complex Based on Maillard Reaction Improves the Mineral Nutrients of Apple (Malus domestica Borkh.)

The metallic complex is widely used in agricultural applications. Due to the oxidation of the metal and environmental unfriendliness of ligand, maintaining an efficient mineral supply for plants without causing environmental damage is difficult. Herein, an antioxidative trimetallic complex with high stability was synthesized by interacting Ca²⁺, Fe²⁺, and Zn²⁺ with the biocompatible ligands from the Maillard reaction. The composite structure elucidation was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR). Thermal stability was measured by thermogravimetric (TG). Antioxidative activities were evaluated by ferric reducing antioxidant power and radical scavenging activity assays. The three metals were successfully fabricated on the Maillard reaction products (MRPs) with contents of Ca (9.01%), Fe (8.25%), and Zn (9.67%). Microscopy images revealed that the three metals were uniformly distributed on the MRPs with partial aggregation of <30 nm. FTIR and XPS results revealed that the metals were interacted with MRPs by metal-O and metal-N bonds. TG and antioxidative activity assays showed that the trimetallic complex meets the requirements of thermodynamics and oxidation resistance of horticultural applications. Additionally, the results of the exogenous spraying experiment showed that the trimetallic complex significantly increased the mineral contents of the "Fuji" apple. By treatment with the complex, the concentrations of Ca, Fe, and Zn were increased by 85.4, 532.5, and 931.1% in the leaf; 16.0, 225.2, and 468.6% in the peel; and 117.6, 217.9, and 19.5% in the flesh, respectively. The MRP-based complexes offered a higher growth rate of the mineral content in apples than ones based on sugars or amino acids. The results of the spraying experiment carried out in 2 years show that the method has high reproducibility. This study thus promotes the development of green metallic complexes and expands the scope of agrochemical strategy.

Preparation and related properties of melanin iron supplement

In this study, BM-Fe (black sesame melanin-iron complex) was prepared and characterized. The results showed that the carboxyl hydroxyl group of BSM (black sesame melanin) participated in the chelation of iron ions. EDS (energy dispersive spectroscopy) and XPS (X-ray photoelectron spectroscopy) results confirmed the presence of iron ions in BM-Fe. The results of DLS (dynamic light scattering) showed that the average particle sizes of BSM and BM-Fe were 844.9 nm and 294.3 nm, respectively, indicating that the structure of BM-Fe with a smaller particle size was formed after the binding of iron ions with the active group on BSM. Finally, the in vitro iron dissolution, iron ion identification, in vitro iron ion reduction, antioxidant activity, cytotoxicity and moisture resistance properties of BM-Fe and FST (ferrous sulfate tablets, a commonly used iron supplement) were comprehensively compared. The results showed that BSM combined with iron instead of physically mixing, and BM-Fe was easily reduced in the gastrointestinal environment. BM-Fe had good bioavailability and retained the excellent characteristics (such as oxidation resistance and biocompatibility) of BSM, and had the potential to be applied in the treatment of iron-deficiency-related diseases. In summary, BM-Fe prepared in this study not only retained the excellent characteristics of BSM but also had a good effect on iron supplementation, high bioavailability and low side effects. Comprehensive analysis showed that the performance of BM-Fe prepared in this study was similar to or even better than that of the control (FST). Thus, BM-Fe is expected to become a new comprehensive multi-functional iron supplement and has a broad developmental prospect.

Magnetic κ-carrageenan/chitosan/montmorillonite nanocomposite hydrogels with controlled sunitinib release

This work aimed to design montmorillonite-incorporated pH-responsive and magnetic κ-carrageenan/chitosan hydrogels via a completely green route for controlled release of sunitinib anticancer drug. This was accomplished by ionic cross-linking of two biopolymers, κ-carrageenan and chitosan, in the presence of magnetic montmorillonite (mMMt) nanoplatelets. Interestingly, it was observed that the amount of mMMt affected not only the microstructure of hydrogels, but also the drug loading efficiency of nanocomposite hydrogels was noticeably increased by introducing mMMt (from 69 to 96%). The in vitro sunitinib release experiments showed that a low content of loaded sunitinib was released from all hydrogels in the buffered solution with pH 7.4. In contrast, a relatively sustained release with a high content of drug release was observed in the acidic solution of pH 5.5. During 48 h, the hydrogels nanocomposite containing a high content of mMMt showed cumulative release of 64.0 and 8.6% at pH 5.5 and 7.4, respectively. During two days, while the cumulative release of sunitinib was obtained 84.3% for the magnetic-free hydrogel, the magnetic ones showed 74.4 and 64% with the low and high contents of magnetic MMt, respectively. The developed κ-carrageenan/chitosan hydrogels with a high capacity of drug loading and subsequent pH-sensitive drug release can be considered in prolonged cancer therapy with reduced side effects.

Transport of arsenic loaded by ferric humate colloid in saturated porous media

The transport behavior of arsenic (As(V)) loaded by ferric humate (HA-Fe) colloid, denoted as HA-Fe/As(V), moving in a saturated quartz sand column, was tested in the laboratory under varying pH values, ionic strengths, and HA and Fe(III) content. The time-fractional advection-dispersion equation (fADE) model was then employed to analyze the observed migration of HA-Fe/As(V). Results showed that the stability of the HA-Fe colloid exhibited an upward trend with an increasing pH and HA content. An increasing HA content led to a decrease in the particle size of the HA-Fe colloid. However, the effect of Fe(III) concentration on colloidal particle size exhibited the opposite phenomenon. The ability of the HA-Fe colloid to load As(V) gradually increased with the increase of the Fe(III) concentration. During the co-transport of the HA-Fe/As(V) colloid, transport of As(V) was promoted with increasing pH, increasing HA and Fe(III) content, and decreasing ionic strength in the saturated porous medium. The transport behavior of As(V) can be well fitted by the fADE model. The model analysis revealed that sub-diffusion of As(V) was weakened in the HA-Fe/As(V) colloid with high HA content. Sub-diffusion of As(V) in the low pH colloid was stronger than that of the high-pH colloid, and the molecular diffusion and mechanical dispersion were more weakened in the high-pH colloid than that of the low-pH colloid. When observing varying ionic strengths, As(V) exhibited stronger sub-diffusion in the HA-Fe/As(V) colloid with a higher ionic strength. As for the Fe(III) content, transport of As(V) was mainly affected by sub-diffusion in the HA-Fe/As(V) colloid with a low Fe(III) content. These findings provided direct and necessary insights into the effects of the HA-Fe colloid on the migration of As(V) throughout saturated porous media under different hydrochemical conditions found in natural environments.

Recent Advances in Natural Gum-Based Biomaterials for Tissue Engineering and Regenerative Medicine: A Review

The engineering of tissues under a three-dimensional (3D) microenvironment is a great challenge and needs a suitable supporting biomaterial-based scaffold that may facilitate cell attachment, spreading, proliferation, migration, and differentiation for proper tissue regeneration or organ reconstruction. Polysaccharides as natural polymers promise great potential in the preparation of a three-dimensional artificial extracellular matrix (ECM) (i.e., hydrogel) via various processing methods and conditions. Natural polymers, especially gums, based upon hydrogel systems, provide similarities largely with the native ECM and excellent biological response. Here, we review the origin and physico-chemical characteristics of potentially used natural gums. In addition, various forms of scaffolds (e.g., nanofibrous, 3D printed-constructs) based on gums and their efficacy in 3D cell culture and various tissue regenerations such as bone, osteoarthritis and cartilage, skin/wound, retinal, neural, and other tissues are discussed. Finally, the advantages and limitations of natural gums are precisely described for future perspectives in tissue engineering and regenerative medicine in the concluding remarks.

Erlotinib-loaded carboxymethyl temarind gum semi-interpenetrating nanocomposites

Erlotinib-loaded carboxymethyl temarind gum-g-poly(N-isopropylacrylamide)-montmorillonite based semi-IPN nanocomposites were synthesized and characterized for their in vitro performances for lung cancer therapy. The placebo matrices exhibited outstanding biodegradability and pH-dependent swelling profiles. The molar mass (M¯ c) between the crosslinks of these composites was declined with temperature. The solid state characterization confirmed the semi-IPN architecture of these scaffolds. The corresponding drug-loaded formulations displayed excellent drug-trapping capacity (DEE, 86-97 %) with acceptable zeta potential (-16 to -13 mV) and diameter (967-646 nm). These formulations conferred sustained drug elution profiles (Q_8h, 77-99 %) with an initial burst release. The drug release profile of the optimized formulation (F-3) was best fitted in the first order kinetic model with Fickian diffusion driven mechanism. The mucin adsorption to F-3 followed Langmuir isotherms. The results of MTT assay, AO/EB staining and confocal analyses revealed that the ERL-loaded formulation suppressed A549 cell proliferation and induced apoptosis more effectively than pristine drug.