The urgent need to develop sustainable materials with reduced environmental impact has driven research into biodegradable and renewable polymer-based alternatives. Among these, starch stands out due to its low cost, natural abundance, biodegradability, and film-forming ability, making it a promising candidate for various industrial applications. However, native starch presents inherent limitations that hinder its widespread use, including poor mechanical properties, high moisture sensitivity, and low thermal stability, which lead to structural degradation over time (Fan and Picchioni, 2020). Consequently, starch modification is essential to overcome these drawbacks and expand its applicability in different fields.

Several strategies have been proposed to improve the properties of starch-based materials. The most common approaches include plasticization to enhance flexibility (Ren et al., 2018), polymer blending to combine desirable characteristics of different materials (Pan et al., 2016), and nanoreinforcement to increase mechanical strength and stability (Llanos and Tadini, 2018). These strategies lead to the formation of thermoplastic starch (TPS), polymer blends, and polymer nanocomposites, respectively, offering enhanced functionalities suited for biomedical, packaging, and other high-performance applications.

Among the polymers commonly blended with TPS, polyvinyl alcohol (PVA) is widely used due to its excellent film-forming ability, water solubility, and adhesive properties (Lin et al., 2022). PVA also improves the mechanical and barrier properties of starch-based materials, making them more resistant to environmental degradation. Additionally, it is biocompatible, non-toxic, and non-carcinogenic, which makes it particularly attractive for biomedical applications, such as drug delivery systems and wound dressings (Britto et al., 2014). However, despite these improvements, TPS/PVA materials still require reinforcement to achieve adequate mechanical strength, durability, and functional stability under real-world conditions.

To address these challenges, cellulose nanocrystals (CNC) have emerged as an effective reinforcement material due to their high crystallinity, exceptional mechanical properties, and compatibility with (Dai et al., 2018, Jiang and Hsieh, 2015, Naz et al., 2016). CNCs contribute to the structural reinforcement of TPS/PVA blends through hydrogen bonding interactions, leading to improved mechanical resistance, thermal stability, and moisture barrier properties (Ulaganathan et al., 2022). Additionally, CNCs have demonstrated bioactivity, promoting cell adhesion and proliferation, which is a key feature in biomedical applications, such as wound healing materials (Montanheiro et al., 2019).

Beyond structural reinforcement, the incorporation of metallic nanoparticles has gained attention for introducing antimicrobial, antioxidant, and controlled release properties in polymeric matrices. Among the available nanometallic additives, copper oxide nanoparticles (NPCuO) are of particular interest due to their broad-spectrum antimicrobial activity, low cost, and biocompatibility drugs (Manyasree et al., 2017, Maheo, 2022). Unlike traditional antibiotics, NPCuO provides a sustained antimicrobial effect, making it a valuable component in wound dressings and biomedical coatings (López et al., 2020, Manyasree et al., 2017, Arezoo et al., 2020). Moreover, its interaction with CNCs can regulate controlled release mechanisms, preventing sudden concentration peaks that might compromise biocompatibility.

This study proposes the development of an innovative TPS/PVA/CNC/NPCuO nanocomposite designed for transdermal biomedical applications, particularly in the field of wound dressings. The combination of biodegradable polymers (TPS/PVA), nanocellulose reinforcement (CNC), and bioactive metallic nanoparticles (NPCuO) aims to create a material that balances mechanical strength, moisture resistance, controlled release properties, and antimicrobial effectiveness. Unlike previous studies, which often focus on isolated aspects of polymeric modification, this work integrates multiple enhancement strategies to develop a high-performance, sustainable material with practical applicability. The formulation is tailored to meet essential criteria for wound dressing applications, including flexibility, biocompatibility, degradability, and ease of removal to minimize secondary injuries during dressing changes. Given the growing demand for effective, affordable, and environmentally sustainable wound healing materials (Matica et al., 2019, O’Callaghan et al., 2020), this research provides a novel approach to nanocomposite design, positioning TPS/PVA/CNC/NPCuO as a promising alternative to conventional synthetic dressings. By combining structural reinforcement, bioactivity, and controlled release functionalities, the developed nanocomposite has the potential to significantly enhance wound healing efficiency while reducing the environmental footprint of biomedical materials.