Spectinomycin-Loaded Antibacterial Polyvinyl Alcohol/Silver Oxide Nanobiocomposite Hydrogel: Synthesis, Characterization, Swelling, Cytotoxicity, and Controlled Drug Release Carrier
Academic Background
In the field of drug delivery, achieving long-term and controlled release of drugs is a significant research direction. Hydrogels, as materials with excellent biocompatibility and degradability, have been widely used in drug delivery, tissue engineering, and wound dressing. However, the low mechanical strength of traditional hydrogels limits their performance in practical applications. To address this issue, researchers have attempted to introduce inorganic nanoparticles into hydrogel networks to enhance their mechanical, thermal, and optical properties. Polyvinyl alcohol (PVA), a water-soluble polymer with good biocompatibility and chemical stability, is often used as a matrix for hydrogels. Additionally, silver oxide (AgO) nanoparticles have garnered attention in the biomedical field in recent years due to their excellent antibacterial properties. This study aims to develop an antibacterial drug-controlled release carrier by incorporating AgO nanoparticles into PVA hydrogels and explore its potential in drug delivery.
Source of the Paper
This paper was co-authored by Abdul Naman, Anfal Fatima, Nasir Mehmood, Minseok Kim, and Sobia Younas, affiliated with Kumoh National Institute of Technology (South Korea) and University of Agriculture Faisalabad (Pakistan). The paper was accepted on April 11, 2025, and published in the journal Bionanoscience, with the DOI 10.1007/s12668-025-01943-1.
Research Process and Results
1. Preparation of PVA Hydrogel
The study first prepared a three-dimensional hydrogel by cross-linking PVA with boric acid. The specific steps included dissolving PVA in a 5% NaOH solution, adding a boric acid solution, and stirring at 60-70°C for 3 hours. The prepared hydrogel was then washed, dried, and ground into powder. The structure of the hydrogel was characterized using Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy, confirming the success of the cross-linking reaction.
2. Incorporation of AgO Nanoparticles
The researchers immersed the dried PVA hydrogel in different concentrations (0%, 1%, 2%, 3%, 4%) of silver nitrate solution for 48 hours, followed by immersion in NaOH solution for 24 hours to convert silver ions into AgO nanoparticles. The morphology and structure of the nanoparticles were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), showing that AgO nanoparticles were uniformly distributed in the PVA hydrogel, with an average particle size of 33.77 nm.
3. Drug Loading and Release
The antibacterial drug spectinomycin was loaded into the PVA/AgO nanocomposite hydrogel, and its swelling behavior in different pH and salt solutions was studied. The results showed that the hydrogel exhibited the maximum swelling rate in a pH 7.4 buffer solution, and the swelling rate increased with the concentration of AgO nanoparticles. The drug release behavior was analyzed using ultraviolet-visible spectrophotometry (UV-Vis) and Raman spectroscopy combined with a partial least squares regression (PLSR) model. It was found that the hydrogel containing 3% AgO nanoparticles exhibited the slowest drug release rate over 32 hours.
4. Antibacterial Activity and Cytotoxicity
The antibacterial activity of the PVA/AgO nanocomposite hydrogel against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was evaluated using the disk diffusion method. The results showed that the hydrogel containing AgO nanoparticles exhibited significant antibacterial effects against both bacteria, with stronger activity against Gram-negative bacteria. Additionally, the cytotoxicity of the hydrogel to human liver cancer cells (HepG2) was assessed using the MTT assay, demonstrating good biocompatibility.
Conclusions and Significance
This study successfully developed a drug-controlled release carrier based on PVA/AgO nanocomposite hydrogel, which exhibits excellent antibacterial properties and drug-controlled release capabilities. The results indicate that the incorporation of AgO nanoparticles not only enhances the mechanical properties of the hydrogel but also significantly improves its antibacterial activity. Furthermore, the hydrogel demonstrated optimal drug release behavior in a pH 7.4 buffer solution, suggesting its broad application prospects in drug delivery. The innovation of this study lies in the uniform distribution of AgO nanoparticles in the PVA hydrogel through an in-situ synthesis method and the systematic investigation of its swelling behavior and drug release characteristics under different environments.
Research Highlights
- Innovative Method: The in-situ synthesis method was used to incorporate AgO nanoparticles into the PVA hydrogel, achieving uniform distribution of nanoparticles.
- Multifunctionality: The developed PVA/AgO nanocomposite hydrogel not only exhibits excellent drug-controlled release capabilities but also demonstrates significant antibacterial activity.
- Application Potential: The hydrogel shows optimal drug release behavior in a pH 7.4 buffer solution, indicating its wide application prospects in drug delivery and tissue engineering.
Additional Valuable Information
This study also explored the swelling behavior of the hydrogel in different salt solutions, finding that the swelling rate significantly decreased with increasing salt concentration. This finding provides important insights for the application of hydrogels in complex physiological environments. Additionally, the study achieved precise prediction of drug release concentrations using Raman spectroscopy combined with the PLSR model, offering a new method for optimizing drug delivery systems.
Through this research, the researchers not only developed a novel drug-controlled release carrier but also provided new ideas and methods for the application of hydrogels in the biomedical field.