## 1 Introduction  
These days, given the current worldwide ecological-related circumstances, social concerns, and growing environmental awareness, new efforts have been initiated in a variety of industries to develop more sustainable new products and processes suitable to the environment. The concerning reasons such as lightweight, convenience, safety, low price, and sounding appealing, which all contributed to the rapid growth in the use of petroleum-derived materials such as polystyrene, polyvinyl chloride, and nylon, with such materials used as biomedical fabrics or for packaging in industrial, and agriculture applications [1], have left a considerable footprint within the environment. A recent study shows that around 8300 million metric tons represent the total amount of waste produced, and the resulting plastic waste is estimated at 6300 million metric tons, of which only 9% has been recycled and 12% is incinerated [2]. Hence, many previous investigations [3; 4; 5; 6; 7] have shown interest in tackling these environmental issues by replacing conventional plastic materials with more eco-friendly fabrics for the abovementioned applications. As is stated above, one of the areas that recently has attracted attention is wound dressing products. Since the skin is the first protective and the largest organ that shields human internal organs from possible hazards outside the person's body, the risk of damage is substantially higher than any other internal organ because it is unprotected and it can break down relatively effortlessly, causing varieties of chronic non-healing wounds [8]. Worldwide, the wound products annual cost for all sorts of wounds has been predicted to be USD 96.8 billion [9]. In 2020, due to the coronavirus disease (COVID-19) pandemic, health care, including wound care, was noticeably disrupted worldwide and emphasized the need for a universal approach to resolving this obstacle [9]. Therefore, the use of biodegradable materials such as starch and polyvinyl alcohol could represent a suitable response to the environmental challenges sparked by synthetic polymers such as nylon and the expansion in the biomedical market requirements. Starch is native, renewable, plentiful, low-priced, biodegradable, and plant-based (corn, wheat grains, potato, and rice) [10], attracting considerable attention to substitute conventional materials. Starch is a unique carbohydrate made of individual soluble granules in water [11]. However, its applications are limited by starch's poor mechanical properties, high brittleness, and reduced water sensitivity. Mainly, adding up other macromolecular compounds into starch can improve the physicochemical properties of the films [12]. Among them, a biodegradable and water-soluble synthetic polymer, polyvinyl alcohol (PVA), is frequently mixed with starch to enhance its properties. PVA also has oil, grease, and solvent resistance. PVA has no odor and is non-toxic. It shows good mechanical properties such as high tensile strength and elongation-at-break. Compared to starch properties, PVA/starch materials possess better degradation, strength, and flexibility characteristics. On the other hand, both polymers are not compatible with one another; therefore, glycerol (GLY) and citric acid (CA) could be added to improve the mechanical properties of the PVA/starch films as plasticizers [10; 13; 14]. Citric Acid (CA) exhibits high acidity; as a result, including citric acid in the solution of the film enhances the antibacterial properties [4; 15; 16], which represents one of the critical requirements for wound dressings. Moreover, compared to glycerol, citric acid carboxyl groups have been identified to form stronger hydrogen bonds with starch-based/polyvinyl alcohol composite films [15].