Fabrication of bilayer hydrogel wound dressings with using chitosan and polyvinyl alcohol and herbal compounds to enhance the healing effects of wound dressing
Fabrication of bilayer hydrogel wound dressings with using chitosan and polyvinyl alcohol and herbal compounds to enhance the healing effects of wound dressing
Farnaz Karbasi,1,*Nazanin Mohammadverdi,2
1. Department of Chemistry, East Tehran Branch, Islamic Azad University, Tehran, Iran 2. Polymer Technology, School of Chemical Engineering, Islamic Azad University, Science and research Branch, Tehran, Iran
Introduction: In recent years, the development of bilayer wound dressings, which consist of two distinct layers with varying properties, has garnered significant attention in the field of wound care. These dressings hold great promise for addressing various aspects of wound management, including pain relief, inflammation reduction, and promoting the overall wound healing process.
The primary objective of our research was to design and evaluate a bilayer hydrogel wound dressing by incorporating herbal compounds and biodegradable polymers. This innovative approach aims to enhance the efficiency of wound care procedures
Methods: To achieve this goal, we focused on the synthesis of the top layer of the wound dressing. We utilized key biomaterials, including a 2 wt% chitosan solution, a 0.5 wt% agar solution, and polyvinyl alcohol (PVA) solution. Our aim was to create three different specimens with various mass ratios of 0.5 wt% agar solution and PVA (20%, 25%, and 30% of each component), while maintaining a constant mass ratio of 50% for the 2 wt% chitosan solution. For the fabrication of non-fluid sublayers, we employed a combination of ingredients, including Ocimum basilicum mucilage, a 2.5 wt% agar solution, and a 9 wt% polyvinyl alcohol solution. These components allowed us to produce three different specimens of sublayers with distinct mass ratios, offering a range of properties and functionalities. To further enhance the therapeutic effects of wound dressing, we introduced curcumin into the sublayer specimens. Curcumin is a bioactive compound known for its anti-inflammatory and wound healing properties. We varied the concentration of curcumin in the sublayers to explore the optimal configuration for promoting wound healing.
In our pursuit of creating an antibacterial wound dressing, we investigated the biosynthesis of silver nanoparticles. The green synthesis method was chosen to minimize the environmental impact and health concerns associated with chemical synthesis. Four different concentrations of silver nanoparticles (0.5 wt%, 1 wt%, 2 wt%, and 3 wt%) were incorporated into the sublayer specimens, allowing us to evaluate their antibacterial properties against various microbial cultures.
Results: Our comprehensive evaluation of the bilayer wound dressing included assessments of curcumin delivery rates, the mechanical properties of the top layer specimens (such as tensile strength and Youngs modulus), antibacterial activity of silver nanoparticles against both gram-negative and gram-positive bacteria, nanoparticle characteristics through Dynamic Light Scattering (DLS) analysis, water absorption capabilities of the specimens, and the analysis of biopolymers, herbal compounds, and synthesized specimens through Fourier transform infrared spectroscopy (FTIR) and scanning calorimetry (DSC).
Our findings revealed that sublayer specimens with higher agar content and lower mucilage content demonstrated the highest curcumin release rates, aligning with our goal of efficient wound healing. Tensile strength tests demonstrated that an increased mass ratio of PVA in the top layer specimens improved the mechanical properties, attributed to elastic characteristics of PVA.
The antibacterial assessments were notable, showing that silver nanoparticles had stronger antibacterial effects on microbial cultures containing gram-negative bacteria, such as Escherichia coli, compared to cultures with gram-positive bacteria, such as Staphylococcus aureus. Furthermore, the concentration of silver nanoparticles in sublayer specimens had a significant impact on their inhibitory effects against gram-negative bacteria.
Dynamic Light Scattering analysis of the nanoparticles revealed a spherical morphology and uniform dispersion, while the water absorption tests indicated that the percentage of water absorption increased with a higher mass ratio of agar in the sublayer specimens. FTIR analysis confirmed the presence of functional groups of chitosan, curcumin, PVA, agar, and silver nanoparticles in both top layers and sublayers.
Lastly, DSC analysis provided insights into the thermal resistance of the sublayer specimens, with increased mass ratios of agar solution and mucilage correlating with improved thermal stability.
Conclusion: In conclusion, our research has successfully developed a bilayer wound dressing that exhibits promising potential in wound care. This dressing offers efficient curcumin delivery, improved mechanical properties, strong antibacterial effects, and noteworthy nanoparticle characteristics. It holds the potential to enhance wound healing processes and revolutionize wound care practices.