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The effective management of deep skin wounds remains a significant healthcare challenge that often deteriorates with bacterial infection, oxidative stress, tissue necrosis, and excessive production of wound exudate. Current medical approaches, including traditional wound dressing materials, cannot effectively address these issues. There is a great need to engineer advanced and multifunctional wound dressings to address this multifaceted problem effectively. Herein, a rationally designed composite cryogel composed of a Copper Metal-Organic Framework (Cu-MOF), tannic acid (TA), polyvinyl alcohol (PVA), and zein protein has been developed by freeze-thaw technique. Cryogels display a remarkable swelling capacity attributed to their interconnected microporous morphology. Moreover, dynamic mechanical behaviour with the characteristics of potent antimicrobial, antioxidant, and biodegradation makes it a desirable wound dressing material. It was further confirmed that the material is highly biocompatible and can release TA and copper ions in a controlled manner. In-vivo skin irritation in a rat model demonstrated that composite cryogel did not provoke any irritation/inflammation when applied to the skin of a healthy recipient. In a deep wound model, the composite cryogel significantly accelerates the wound healing rate. These findings highlight the multifunctional nature of composite cryogels and their promising potential for clinical applications as advanced wound dressings.

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Supermacroporous composite cryogels with enhanced adjustable functionality have received extensive interest in bioseparation, tissue engineering, and drug delivery. However, the variations in their components significantly impactfinal properties. This study presents a two-step hybrid machine learning approach for predicting the properties of innovative poly(2-hydroxyethyl methacrylate)-poly(vinyl alcohol) composite cryogels embedded with bacterial cellulose (pHEMA-PVA-BC) based on their compositions. By considering the ratios of HEMA (1.0-22.0 wt%), PVA (0.2-4.0 wt%), poly(ethylene glycol) diacrylate (1.0-4.5 wt%), BC (0.1-1.5 wt%), and water (68.0-96.0 wt%) as investigational variables, overlay sampling uniform design (OSUD) was employed to construct a high-quality dataset for model development. The random forest (RF) model was used to classify the preparation conditions. Then four models of artificial neural network, RF, gradient boosted regression trees (GBRT), and XGBoost were developed to predict the basic properties of the composite cryogels. The results showed that the RF model achieved an accurate three-class classification of preparation conditions. Among the four models, the GBRT model exhibited the best predictive performance of the basic properties, with the mean absolute percentage error of 16.04 %, 0.85 %, and 2.44 % for permeability, effective porosity, and height of theoretical plate (1.0 cm/min), respectively. Characterization results of the representative pHEMA-PVA-BC composite cryogel showed an effective porosity of 81.01 %, a permeability of 1.20 × 10-12 m2, and a range of height of theoretical plate between 0.40-0.49 cm at flow velocities of 0.5-3.0 cm/min. These indicate that the pHEMA-PVA-BC cryogel was an excellent material with supermacropores, low flow resistance and high mass transfer efficiency. Furthermore, the model output demonstrates that the alteration of the proportions of PVA (0.2-3.5 wt%) and BC (0.1-1.5 wt%) components in composite cryogels resulted in significant changes in the material basic properties. This work represents an attempt to efficiently design and prepare target composite cryogels using machine learning and providing valuable insights for the efficient development of polymers.

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Polysaccharide-based cryogels are promising materials for producing scaffolds in tissue engineering. In this work, we obtained ultralight (0.046-0.162 g/cm3) and highly porous (88.2-96.7%) cryogels with a complex hierarchical morphology by dissolving cellulose in phosphoric acid, with subsequent regeneration and freeze-drying. The effect of the cellulose dissolution temperature on phosphoric acid and the effect of the freezing time of cellulose hydrogels on the structure and properties of the obtained cryogels were studied. It has been shown that prolonged freezing leads to the formation of denser and stronger cryogels with a network structure. The incorporation of chitin nanowhiskers led to a threefold increase in the strength of the cellulose cryogels. The X-ray diffraction method showed that the regenerated cellulose was mostly amorphous, with a crystallinity of 26.8-28.4% in the structure of cellulose II. Cellulose cryogels with chitin nanowhiskers demonstrated better biocompatibility with mesenchymal stem cells compared to the normal cellulose cryogels.

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Highly porous composite poly(vinyl alcohol) (PVA) cryogels loaded with the poly(3-hydroxybutyrate) (PHB) microbeads containing the drug, simvastatin (SVN), were prepared via cryogenic processing (freezing-storing frozen-defrosting) of the beads' suspensions in aqueous PVA solution. The rigidity of the resultant composite cryogels increased with increasing the filler content. Optical microscopy of the thin section of such gel matrices revealed macro-porous morphology of both continuous (PVA cryogels) and discrete (PHB-microbeads) phases. Kinetic studies of the SVN release from the drug-loaded microbeads, the non-filled PVA cryogel and the composite material showed that the cryogel-based composite system could potentially serve as a candidate for the long-term therapeutic system for controlled drug delivery. Such PHB-microbeads-containing PVA-cryogel-based composite drug delivery carriers were unknown earlier; their preparation and studies have been performed for the first time.

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Construction of monolithic cryogels that can efficiently adsorb proteins is of great significance in biotechnological and pharmaceutical industries. Herein, a novel approach is presented to fabricate microfibrillated cellulose (MFC)/sodium alginate (SA) cryogels by using freezing-induced oxa-Michael reaction at -12 °C. Thanks to the controllable reactiveness of divinyl sulfone (DVS), cryo-concentrated pH increase activates the oxa-Michael reaction between DVS and hydroxyl groups of MFCs and SAs. The obtained composite cryogel exhibits outstanding underwater shape recovery and excellent fatigue resistance. Moreover, the MFC/SAs reveal a high lysozyme adsorption capacity of 294.12 mg/g, surpassing most of absorbent materials previously reported. Furthermore, the cryogel-packed column can purify lysozyme continuously from chicken egg white, highlighting its outstanding practical application performance. Reuse experiments indicated that over 90% of lysozyme extraction capacity was retained after 6 cycles. This work provides a new avenue to design and develop next-generation chromatographic media of natural polysaccharide-based cryogel for protein purification.

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We present here preparation of mechanically strong and biocompatible cryogel composites based on hyaluronic acid (HA) and halloysite nanotubes (HNTs) of various compositions, and their applications as scaffold for different cell growing media. Uniaxial compression tests reveal that the incorporation of HNTs into HA cryogels leads to a ~2.5-fold increase in their Young moduli, e.g., from 38 ±â€¯1 to 99 ±â€¯4 kPa at a HA:HNTs weight ratio of 1:2. Although HA:HNTs based cryogels were found to be blood compatible with 1.37 ±â€¯0.11% hemolysis ratio at a HA:HNTs weight ratio of 1:2, they trigger thrombogenic activity with a blood clotting index of 17.3 ±â€¯4.8. Remarkably, HA:HNTs cryogel composites were found to be excellent scaffold materials in the proliferation of rat mesenchymal stem cells (MSC), human cervical carcinoma cells (HeLa), and human colon cancer cells (HCT116). The cell studies revealed that an increased amount of HNT embedding into HA cryogels leads to an increase of MSC proliferation.

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Naturally produced by the human immune system, immunoglobulin nowadays is widely used for in vivo and in vitro purposes. The increased needs for pure immunoglobulin have prompted researchers to find new immunoglobulin chromatographic separation processes. Cryogels as chromatographic adsorbents, congregate several mechanical features including good compatibility, large pore structure, flexibility, short diffusion pathway and stability. These different characteristics make them a good alternative to conventional chromatographic methods and allowing their potential use in separation technology. In the present study, two sets of poly(2-hydroxyethyl methacrylate) (PHEMA) based beads were prepared and functionalized with Reactive Red 120 (RR) and Reactive Green HE 4BD (RG) dyes, and then embedded into supermacroporous cryogels. The morphology, physical and chemical features of the prepared bead embedded composite cryogel discs (CCDs) were performed by scanning electron microscopy (SEM), swelling test, elemental analysis and Fourier transform infrared spectroscopy (FTIR). The results showed that the embedded composite cryogel discs have a specific surface area of 192.0 m(2)/g with maximum adsorption capacity of HIgG 239.8 mg/g for the RR functionalized CCD and 170 mg/g for RG functionalized CCD columns, both at pH 6.2.

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