Chitosan/poly(dimethylaminoethylmethacrylate-co-hydroxyethylacrylate) based semi-IPN hydrogels and silver nanocomposites: Synthesis, evaluation of amoxicillin release studies, and antibacterial studies

A review on Ag nanoparticles fabricated in microgels

In recent years, there has been growing interest in the composites of multi-responsive microgels and silver nanoparticles. This innovative hybrid system harnesses the responsive qualities of microgels while capitalizing on the optical and electronic attributes of silver nanoparticles. This combined system demonstrates a rapid response to minor changes in pH, temperature, ionic strength of the medium, and the concentration of specific biological substances. This review article presents an overview of the recent advancements in the synthesis, classification, characterization methods, and properties of microgels loaded with silver nanoparticles. Furthermore, it explores the diverse applications of these responsive microgels containing silver nanoparticles in catalysis, the biomedical field, nanotechnology, and the mitigation of harmful environmental pollutants.

Composite Microgels Loaded with Doxorubicin-Conjugated Amine-Functionalized Zinc Ferrite Nanoparticles for Stimuli-Responsive Sustained Drug Release

Purpose

The purpose of this study is to address the need for efficient drug delivery with high drug encapsulation efficiency and sustained drug release. We aim to create nanoparticle-loaded microgels for potential applications in treatment development.

Methods

We adopted the process of ionic gelation to generate microgels from sodium alginate and carboxymethyl cellulose. These microgels were loaded with doxorubicin-conjugated amine-functionalized zinc ferrite nanoparticles (AZnFe-NPs). The systems were characterized using various techniques. Toxicity was evaluated in MCF-7 cells. In vitro release studies were conducted at different pH levels at 37 oC, with the drug release kinetics being analyzed using various models.

Results

The drug encapsulation efficiency of the created carriers was as high as 70%. The nanoparticle-loaded microgels exhibited pH-responsive behavior and sustained drug release. Drug release from them was mediated via a non-Fickian type of diffusion.

Conclusion

Given their high drug encapsulation efficiency, sustained drug release and pH-responsiveness, our nanoparticle-loaded microgels show promise as smart carriers for future treatment applications. Further development and research can significantly benefit the field of drug delivery and treatment development.

Methylene blue uptake by gum arabic/acrylic amide/3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt semi-IPN hydrogel

In this study, the capacity of methylene blue (MB) uptake from aqueous solution was investigated using acrylic amide-co-3-Allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt/Gum Arabic semi-IPN hydrogel. The semi-IPN hydrogels were prepared by the classical free radical solution technique. The swelling experiments were carried out gravimetrically and the swelling kinetics parameters were calculated. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) confirmed the semi-IPN hydrogel formation. The MB uptake was studied by the batch technique and the impact of different conditions was investigated. It was found that the obtained semi-IPN hydrogels gave adsorption capacity for the dye within a range of 101-187 mg g^-1 at the initial dye concentration of 100 mg/L. The adsorption kinetics (pseudo-first-order and pseudo-second-order) and the adsorption isotherms (Langmuir, Freundlich, and Temkin equations) were tested and the adsorption data was well described by the pseudo-second-order and Freundlich models, respectively. The maximum adsorption capacity calculated by the Langmuir model (R² = 0.8718) was 655.2 mg g^-1. The thermodynamic study indicated the spontaneity and the endothermic nature of MB adsorption. Furthermore, the usability study showed that the prepared adsorbents could be employed repeatedly for successive 5 cycles of adsorption and desorption.

Synthesis and Characterization of Polyfumarateurethane Nanoparticles for Sustained Release of Bupivacaine

Biodegradable polyfumarateurethane (PFU) for use as a bupivacaine delivery vehicle, synthesized using di-(2-hydroxypropyl fumarate) (DHPF), polyethylene glycol (PEG) and 1,6-hexamethylene diisocyanate (HMDI), was designed to be degradable through the hydrolysis and enzymatic degradation of the ester bonds in its polymer backbone. Using a water-in-oil-in-water double emulsion techniques, nanoparticles encapsulating water or fluorescein isothiocyanate (FITC) were fabricated to avoid the immune system owing to the presence of PEG on their surface. The morphologies of these nanoparticles were characterized by DLS, TEM, FE-SEM, and fluorescent microscopies. The present study explored the encapsulation, loading efficiency and in vitro drug release of bupivacaine encapsulated with biodegradable PFU nanoparticles for the treatment of local anesthesia. Various concentrations of bupivacaine were encapsulated into nanoparticles and their encapsulation efficiencies and drug loading were investigated. Encapsulation efficiency was highest when 2.5% bupivacaine was encapsulated. Drug release behavior from the bupivacaine-loaded PFU nanoparticles followed a sustained release profile.

Antibacterial effects and ibuprofen release potential using chitosan microspheres loaded with silver nanoparticles

The wide use of chitosan microspheres in pharmaceutical applications, mainly in the controlled release of drugs and as a bactericidal agent, has been widely reported in the literature. However, these important biomaterial applications with multifunctionality is still scarce. In this study, epichlorohydrin-crosslinked chitosan microspheres were prepared and evaluated for Ag+ adsorption and formation of silver nanoparticles. The hybrid material obtained was used to antibacterial activity and controlled drug release. The optimal pH for adsorption of Ag+ ions in aqueous medium was pH 5-7; the best fit was the Langmuir model; the optimal time for maximum adsorption was 10 h. The highest release of the drug occured at neutral pH of the intestinal fluids and remained constant for 6 h. Silver ion microspheres demonstrated activity against E. coli and S. aureus. The concentration of ibuprofen incorporated in the chitosan microspheres was 7.9 × 10^-3 mol L^-1 and in the microspheres with AgNPs the concentration was 1.8 × 10^-2 mol L^-1. The microspheres with AgNPs released more drug (77%) than the material without AgNPs.