## 1 Introduction  
Radiotherapy is a cancer treatment, often employed for breast cancer, head and neck cancer, and cervical cancer, that uses high doses of ionizing radiation to destroy cancer cells or to shrink the tumor. However, radiodermatitis can easily appear on radiation-sensitive skin when it is high-energy radiation penetrated. Clinically, 95% of cancer patients receiving radiotherapy will develop some form of radiodermatitis [1]. Up to 85% of patients will have moderate to severe inflammation. Acute inflammation mostly occurs from the first week to the fourth week of radiotherapy and causes capillary dilation and damage, dermal endothelial cell mutation, mass inflammatory cell infiltration, and tissue necrosis [2; 3; 4]. Serious cases often recover only after two to four weeks, or even longer after therapy has concluded. In clinical care, moist skin care with 3% urea lotion delays the occurrence and reduces the grade of acute skin reactions in percutaneously irradiated patients with head and neck tumors [5]. A previous study has demonstrated that patients who used urea cream for radiotherapy aftercare had a 50% lower chance of developing radiodermatitis compared to the control group [6]. In contrast, aloe vera gel is widely used in clinical care due to its low-cost and wide availability [7]. Compared to aqueous cream, aloe vera gel is beneficial for reducing the identified skin side-effects of radiotherapy [8]. However, there are no drugs or products that are guaranteed to prevent dermatitis. Wound dressings are also a suitable option during the aftercare process. [PERSON] et al., noted a gradual increase in the clinical use of hydrophilic dressings with tight seals, which not only provide a good setting for dry desquamation and moist desquamation care, but also promote cell growth and migration [3]. In contrast with traditional dry wound repair methods, mock-natural extracellular matrix (ECM)-based biomedical materials as wound dressings can act as a support for promoting cell growth by creating environments similar to those inside the body for in vitro cells [9]. These dressings provide a moist environment so that the cells involved in tissue repair, such as fibroblasts and epithelial cells, can migrate quickly and proliferate, thus promoting wound healing while absorbing copious amounts of the interstitial fluid produced during wound repair. Biomedical materials based on blends of polymers made from different materials not only provide the benefits of these polymers, but also improve physical properties. In addition to facilitating cell repair by acting as a shield that protects an injured area as well as helping the skin to recover its normal functions, a good dressing can also absorb the interstitial fluid discharged during wound repair, which can also be absorbed by the body during fibrous tissue degradation. Gel-based dressings can also act as drug carriers for fabricating long-lasting functional dressings with decent restorative effects for injured areas. Furthermore, polyvinyl pyrrolone (PVP), chitosan, and gelatin have been widely used in the study of wound dressings [10; 11; 12]. PVP is a water-soluble, biodegradable, synthetic polymer. Due to its excellent biocompatibility, PVP has been used in numerous biomedical applications, such as implants, drug delivery devices [13], and wound dressings [14]. However, PVP is an amphiphile substances. It produces strong hydrogen bonding with chitosan and gelatin. PVP combined with gelatin can increase solution viscosity and is helpful for the production of films and hydrogels [11; 12]. PVP and chitosan have previously been mixed into a film to improve the mechanical properties of the film and increase its water vapor permeability and antibacterial properties [10]. A PVP and chitosan composite hydrogel showed dual properties by supporting the growth of epithelial cells (SiHa) and selectively inhibiting fibroblast (NIH3T3) growth. The mechanical strength and hydrophilicity of the composite was higher than pure chitosan membrane.