Hemostatic Cryogels Based on Oxidized Pullulan/Dopamine with Potential Use as Wound Dressings The impetus for research into hydrogels based on selectively oxidized polysaccharides has been stimulated by the diversity of potential biomedical applications. Towards the development of a hemostatic wound dressing in this study, we creatively combined the (hemi)acetal and Schiff base bonds to prepare a series of multifunctional cryogels based on dialdehyde pullulan and dopamine. The designed structures were verified by NMR and FTIR spectroscopy. Network parameters and dynamic sorption studies were correlated with environmental scanning microscopy results, thus confirming the successful integration of the two components and the opportunities for finely tuning the structure–properties balance. The viscoelastic parameters (storage and loss moduli, complex and apparent viscosities, zero shear viscosity, yield stress) and the structural recovery capacity after applying a large deformation were determined and discussed. The mechanical stability and hemostatic activity suggest that the optimal combination of selectively oxidized pullulan and dopamine can be a promising toolkit for wound management.To get more news about hemostatic dressings, you can visit rusuntacmed.com official website. Hydrogels are regarded as the most promising contender among the many different materials used for wound dressing because of their one-of-a-kind qualities, including their soft nature, great flexibility, a tremendous capacity for retaining water, and high level of biocompatibility [1,2]. Hydrogels that can self-heal after being damaged have recently attracted a lot of interest because of their ability to function similarly to human tissues in this regard [3,4,5,6]. Because of their rapid in situ formation, dynamic reversibility, and environmental pH responsiveness, the Schiff base bond has been regarded as a good choice among the various methods of fabrication available. For these reasons, it can be successfully chosen to fabricate self-healing hydrogels that can be most suitable for bleeding wound management [2,7,8,9]. However, due to their poor mechanical resistance and tissue adhesion performance, Schiff base cross-linked self-healing hydrogels have a limited impact on wound healing on their own. Consequently, it is still difficult to achieve high mechanical and adhesive strength without sacrificing self-healing capability and biocompatibility. In recent years, it has become known that polysaccharide derivatives that include aldehyde groups may function very well as efficient cross-linking reagents for polymers that contain amino groups. Synthesis and application of dialdehyde alginate [10,11,12], dialdehyde cellulose [13,14,15], dialdehyde dextran [16], dialdehyde carboxymethyl cellulose [17,18,19], and dialdehyde xanthan gum [20] have been obtained in the past aiming to fabricate cross-linked films, fibers, and cryogels. These materials were primarily designed for use in food or biomedical applications. Another candidate very well suited for preparing physically and/or chemically cross-linked hydrogels is pullulan. Multiple species of the bacterium Aureobasidium produce pullulan, a linear repeating polysaccharide that is both water-soluble and biodegradable [21]. It is made up of hundreds of glucose units that are repeated, and each one is connected to the next by -1,6-, and -1,4-glycosidic linkages. Pullulan possesses outstanding biological and physical features, including the qualities of being atoxic, edible, biocompatible, biodegradable, and water-soluble, in addition to possessing adhesive qualities [22,23]. Because of the presence of a variety of glycosidic linkages, it has physicochemical characteristics that are unique [24]. Pullulan is capable of undergoing a variety of chemical transformations, which may result in the formation of derivatives with significantly altered structures and characteristics. One of the reactive derivatives that may be formed from the periodate [25,26] or TEMPO [27] selective oxidation of pullulan is a compound known as pullulan dialdehyde, which contains polyaldehyde structures. Due to the presence of three distinct anhydroglucose rings in the repeating unit of pullulan, oxidation with periodate will produce many distinct forms of dialdehyde compounds [25]. These active groups have the potential to react with the free amino groups in a way that is analogous to that of glutaraldehyde, alginate dialdehyde, dialdehyde cellulose, dextran dialdehyde, oxidized xanthan gum, and other related compounds. In the past, pullulan was combined with sodium periodate (NaIO4) and human-like collagen at the same time to produce hydrogels for use in skin restoration [19]. In more recent times, it has been observed that oxidized pullulan that contains carboxyl groups may speed up the process of network formation in PVA hydrogels [22]. Given the experience of our research group in obtaining polysaccharides functionalized using selective oxidation methods, particularly pullulan, and their further use for preparing hydrogels [22,28,29,30], we propose in this study a new polymeric system. We hypothesized that periodate-oxidized pullulan can form stable hydrogels based on (hemi)acetal bonds and additional dopamine can be incorporated with success by interacting with the aldehyde groups, improving the stability of the networks. This polysaccharide-based material should exhibit self-healing behavior, good swelling degree and excellent hemostatic activity, and therefore specific characterizations were performed.