Bioactive Carboxymethyl Starch-Based Hydrogels Decorated with CuO Nanoparticles: Antioxidant and Antimicrobial Properties and Accelerated Wound Healing In Vivo.

Zahra Abdollahi,Franklin R Tay,Iran Goudarzi,Fatemeh Salimi,Ehsan Nazarzadeh Zare,Pooyan Makvandi

doi:10.3390/ijms22052531

Abstract

In this study, nanocomposite hydrogels composed of sodium carboxymethylated starch (CMS)-containing CuO nanoparticles (CMS@CuO) were synthesized and used as experimental wound healing materials. The hydrogels were fabricated by a solution-casting technique using citric acid as a crosslinking agent. They were characterized by Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to evaluate their physicochemical properties. In addition, swelling, antibacterial activities, antioxidant activities, cytotoxicity, and in vivo wound healing were investigated to evaluate the wound healing potential of the CMS@CuO nanocomposite hydrogels. Growth inhibition of the Gram-positive and Gram-negative pathogens, antioxidant activity, and swelling were observed in the CMS@CuO nanocomposite hydrogels containing 2 wt.% and 4 wt.% CuO nanoparticles. The hydrogel containing 2 wt.% CuO nanoparticles displayed low toxicity to human fibroblasts and exhibited good biocompatibility. Wounds created in rats and treated with the CMS@2%CuO nanocomposite hydrogel healed within 13 days, whereas wounds were still present when treated for the same time-period with CMS only. The impact of antibacterial and antioxidant activities on accelerating wound healing could be ascribed to the antibacterial and antioxidant activities of the nanocomposite hydrogel. Incorporation of CuO nanoparticles in the hydrogel improved its antibacterial properties, antioxidant activity, and degree of swelling. The present nanocomposite hydrogel has the potential to be used clinically as a novel wound healing material.

Highlights

The carboxymethylated starch (CMS)@2%CuO nanocomposite hydrogel was thermally more stable than CMS. These results indicate that the incorporation of CuO nanoparticles into CMS increased the thermal stability of the nanocomposite hydrogel
The results indicate that the inclusion of antibacterial components (CMS and CuO nanoparticles) improves the antibacterial function of the hydrogel destined for wound healing
Results from the present study showed that the CMS and CMS matrix and CuO nanoparticles (CMS@CuO) hydrogels were able to kill eight species of Gram-positive and Gram-negative bacteria that are pathogenic to humans

Summary

Introduction

Deprivation of nutritional factors adversely affects cellular differentiation, immune functions, and collagen formation that are vital for optimal wound healing [1]. An important factor for appropriate wound healing is the redox state of the wound tissue [2]. The redox state is preserved via an equilibrium between oxidant and antioxidant molecules. Oxidative stress occurs in tissues and cells when there is a disbalance between the reactive oxygen species (ROS) level and the antioxidant capability of the tissue or cells to eliminate. ROS and repair the damage they cause [3,4,5]. ROS in low levels are crucial for the commencement and progression of wound healing, high ROS levels disrupt the

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Discussion

Conclusion