Synthesis and characterization of pectin-6-aminohexanoic acid-magnetite nanoparticles for drug delivery

Injectable Ca/ε-aminocaproic acid/dextran phosphate hydrogel for effective acute bleeding control

The development of new hemostatic agents is crucial for advancing medical treatments and improving outcomes in surgical and trauma settings, where controlling bleeding is often a critical challenge. Herein, we developed and characterized the physicochemical properties and hemostatic potential of Ca/ε-aminocaproic acid/dextran phosphate composite hydrogels. The phosphorylation of dextran in the system tributyl phosphate - orthophosphoric acid - phosphorus (V) oxide - chloroform at 30 °C with the formation of hydrogels was studied in detail. We explored physical and chemical properties of the hydrogels, including rheology, swelling, and morphology. Additionally, the sorption kinetics and isotherms of ε-aminocaproic acid by the hydrogels were studied, revealing a maximum sorption capacity of 80 %. The hydrogels rapidly released ε-aminocaproic acid in vitro at 37 °C in PBS. Significantly, they demonstrated in vitro effectiveness by reducing blood clotting time, enhancing the clotting index, and showing minimal hemolysis. In vivo tests further indicated that these hydrogels markedly decreased bleeding time and average blood loss in a rat liver hemorrhage model, surpassing control experiments. These results suggest that Ca/ε-aminocaproic acid/dextran phosphate hydrogels are effective in controlling bleeding and show promise as a future hemostatic agent.

Extraction of gamma iron oxide (γ-Fe2O3) nanoparticles from waste can: Structure, morphology and magnetic properties

In this work, the transformation of waste iron cans to gamma iron oxide (γ-Fe2O3) nanoparticles following acid leaching precipitation method along with their structural, surface chemistry, and magnetic properties was studied. Highly magnetic iron-based nanomaterials, maghemite with high saturation magnetization have been synthesized through an acid leaching technique by carefully tuning of pH and calcination temperature. The phase composition and crystal structure, surface morphology, surface chemistry, and surface composition of the synthesized γ-Fe2O3 nanoparticles were explored by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Energy-dispersive X-ray spectroscopy (EDS). The XRD results confirm the cubic spinel structure having crystallite size 26.90-52.15 nm. The XPS study reveals the presence of Fe, O element and the binding energy of Fe (710.31 and 724.48 eV) confirms the formation of γ-Fe2O3 as well. By dynamic light scattering (DLS) method and zeta potential analyzer, the particle size distribution and stability of the systems were investigated. The magnetic behavior of the synthesized γ-Fe2O3 nanoparticles were studied using a vibrating sample magnetometer (VSM) which confirmed the ferrimagnetic particles with saturation magnetization of 54.94 emu/g. The resultant maghemite nanoparticles will be used in photocatalysts and humidity sensing. The net impact of the work stated here is based on the principle of converting waste into useful nanomaterials. Finally, it was concluded that our results can give insights into the design of the synthesis procedure from the precursor to the high-quality gamma iron oxide nanoparticles with high saturation magnetization for different potential applications which are inexpensive and very simple.

Energetic Electron-Assisted Synthesis of Tailored Magnetite (Fe3O4) and Maghemite (γ-Fe2O3) Nanoparticles: Structure and Magnetic Properties

Iron oxide nanoparticles with a mean size of approximately 5 nm were synthesized by irradiating micro-emulsions containing iron salts with energetic electrons. The properties of the nanoparticles were investigated using scanning electron microscopy, high-resolution transmission electron microscopy, selective area diffraction and vibrating sample magnetometry. It was found that formation of superparamagnetic nanoparticles begins at a dose of 50 kGy, though these particles show low crystallinity, and a higher portion is amorphous. With increasing doses, an increasing crystallinity and yield could be observed, which is reflected in an increasing saturation magnetization. The blocking temperature and effective anisotropy constant were determined via zero-field cooling and field cooling measurements. The particles tend to form clusters with a size of 34 nm to 73 nm. Magnetite/maghemite nanoparticles could be identified via selective area electron diffraction patterns. Additionally, goethite nanowires could be observed.

Pectin in biomedical and drug delivery applications: A review

Natural macromolecules have attracted increasing attention due to their biocompatibility, low toxicity, and biodegradability. Pectin is one of the few polysaccharides with biomedical activity, consequently a candidate in biomedical and drug delivery Applications. Rhamnogalacturonan-II, a smaller component in pectin, plays a major role in biomedical activities. The ubiquitous presence of hydroxyl and carboxyl groups in pectin contribute to their hydrophilicity and, hence, to the favorable biocompatibility, low toxicity, and biodegradability. However, pure pectin-based materials present undesirable swelling and corrosion properties. The hydrophilic groups, via coordination, electrophilic addition, esterification, transesterification reactions, can contribute to pectin's physicochemical properties. Here the properties, extraction, and modification of pectin, which are fundamental to biomedical and drug delivery applications, are reviewed. Moreover, the synthesis, properties, and performance of pectin-based hybrid materials, composite materials, and emulsions are elaborated. The comprehensive review presented here can provide valuable information on pectin and its biomedical and drug delivery applications.

Multifunctional magnetite nanoparticles for drug delivery: Preparation, characterisation, antibacterial properties and drug release kinetics

Multifunctional nanoparticles (NPs) with magnetic (M) and antibacterial properties were prepared for drug delivery purposes by a method involving co-precipitation synthesis. Partial and complete substitutions of ferrous ions (Fe²⁺) by copper ions (Cu²⁺) were carried out for the preparation of the magnetite NPs, which are designated as Cu_0.5M and CuM, respectively, in this work. In addition, chitosan and ciprofloxacin were hybridized with the NPs from the previous step to achieve multifunctional properties. XRD, TEM, SEM/EDAX, VSM and FTIR were subsequently employed to characterize various properties of the prepared NPs, namely, crystallinity, nanostructure (size), particle morphology, elemental mapping, magnetic strength and chemical composition. Antibacterial properties of the NPs were tested against Bacillus cereus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria) and Candida albicans (yeast). Efficiency of the ciprofloxacin release was also studied for the drug-loaded NPs. It is demonstrated that the obtained NPs possess mixed phases with crystalline structures that are affected by the degree of Cu ion substitution (5-10 nm (M), 2.5-3.5 nm (Cu_0.5M) and 11-16 nm (CuM)). Saturation magnetization values of the NPs were recorded as 38.7, 3.5 and 1.3 emu/g, respectively. It was also found that the introduction of Cu ions in the NP samples improved the significance of their antibacterial activity, especially against Escherichia coli. Chitosan and ciprofloxacin were found to have stronger effects against Bacillus cereus and Escherichia coli and lesser effects against Candida albicans. However, the samples containing chitosan, ciprofloxacin and the higher Cu ion concentration exhibited strong influence against Candida albicans. During a study period of 30-days, the amounts of released drug from the tested NPs were 85, 26 and 20% of the originally loaded amount, respectively. Owing to the findings in this paper, the developed NPs are considered to have good potential for drug delivery applications and to study them further such as in pre-clinical studies.

Magnetite-based catalysts for wastewater treatment

The increasing number and concentration of organic pollutants in water stream could become a serious threat in the near future. Magnetite has the potential to degrade pollutants via photocatalysis with a convenient separation process. This study discusses in detail the control size and morphology of magnetite nanoparticles, and their composites with co-precipitation, hydrothermal, sol-gel, and electrochemical route. Further photocatalytic enhancement with the addition of metal and porous support was proposed. This paper also discussed the technology to extend the lifetime of recombination through an in-depth explanation of charge transfer. The possibility to use waste materials as catalyst support was also elucidated. However, magnetite-based photocatalysts still require many improvements to meet commercialization criteria.

Pectin-decorated magnetite nanoparticles as both iron delivery systems and protective matrices for probiotic bacteria

The goal of this work was to investigate biophysical stability of iron-pectin nanoparticles and analyze the feasibility of using them as delivery systems for the probiotic strain Lactobacillus plantarum CIDCA 83114. Iron oxide (Fe₃O₄) nanoparticles were synthesized from 0.25M FeCl₂/0.5 M FeCl₃.6H₂O, and coated with citrus pectins. Their physico-chemical properties [FTIR, X-ray diffraction (XRD), ζ-potential, particle size, SEM, TEM] and their effect on bacterial stabilization (viability after freeze-drying/storage, stability when exposed to simulated gastro-intestinal conditions) were assessed. XRD indicated the almost exclusive presence of magnetite crystalline phases. FTIR spectra confirmed the adsorption of pectin on magnetite nanoparticles surface. SEM and TEM images evidenced agglomerated nanoparticles, and a morphological surface change after adsorption of pectin. DLS and ζ-potential results proved the solvation of the ionizable groups in the hydrophilic network which induced chain expansion and agglomeration. Iron from nanoparticles demonstrated to be non-toxic for microorganisms up to 1.00 mg/mL. Simulated saliva and gastric solutions prevented nanoparticles from dissolution. The higher pH of the intestinal conditions (solvated -COO- and Fe-O- groups) facilitated the dispersion and partial dissolution of nanoparticles. Pectins adsorption on magnetite nanoparticles significantly enhanced electrostatic repulsion, which aided the solvation of ionized iron forms. The soluble species diffused out from the aggregates, being detected in the simulated intestinal fluid. Regarding bacterial viability, no decays were observed neither when pectin-decorated nanoparticles were exposed to simulated fluids nor when stored at 4 °C for 60 days. The composites engineered in this work appear as adequate delivery systems for probiotic bacteria, whose target is the gut.