Evaluation of natural gum-based cryogels for soft tissue engineering

Cryogel Scaffolds for Tissue-Engineering: Advances and Challenges for Effective Bone and Cartilage Regeneration

Critical-sized bone defects and articular cartilage injuries resulting from trauma, osteonecrosis, or age-related degeneration can be often non-healed by physiological repairing mechanisms, thus representing a relevant clinical issue due to a high epidemiological incidence rate. Novel tissue-engineering approaches have been proposed as an alternative to common clinical practices. This cutting-edge technology is based on the combination of three fundamental components, generally referred to as the tissue-engineering triad: autologous or allogenic cells, growth-stimulating factors, and a scaffold. Three-dimensional polymer networks are frequently used as scaffolds to allow cell proliferation and tissue regeneration. In particular, cryogels give promising results for this purpose, thanks to their peculiar properties. Cryogels are indeed characterized by an interconnected porous structure and a typical sponge-like behavior, which facilitate cellular infiltration and ingrowth. Their composition and the fabrication procedure can be appropriately tuned to obtain scaffolds that match the requirements of a specific tissue or organ to be regenerated. These features make cryogels interesting and promising scaffolds for the regeneration of different tissues, including those characterized by very complex mechanical and physical properties, such as bones and joints. In this review, state-of-the-art fabrication and employment of cryogels for supporting effective osteogenic or chondrogenic differentiation to allow for the regeneration of functional tissues is reported. Current progress and challenges for the implementation of this technology in clinical practice are also highlighted.

Development of a novel cryostructured composite coating of xanthan-bovine collagen-oregano essential oil spraying applied for the preservation of commercial biscuits marketed in Mexico

Cryostructured gels, better known as cryogels, are a very important emerging class of biomaterials that have diverse applications in food preservation. This work shows a novel alternative to prepare a cryostructured composite coating made from a blend of xanthan, bovine collagen, and oregano essential oil. The composite coating was suitably applied onto the surface of preservative-free biscuits which were stored for 15 days at 25 ± 2°C and 52% ± 1% relative humidity. The evaluation focused mainly on the changes in the physicochemical, textural, and microbiological characteristics of the biscuits. It was found that the coated samples significantly (p < 0.05) decreased moisture absorption, water activity, and fungal growth. However, the composite coating minimally impacted the quality of biscuits in terms of color, texture profile, and surface microstructure. Overall, the cryostructured composite coating constitutes an advance in technological strategies aimed at the preservation of baked products. This will allow, in the future, the development of novel coatings on bakery products to generate new trends in the conservation of their properties and extension of shelf life. This could be achieved through the implementation of new technologies in the food industry, with the aim of making them more environmentally friendly and contributing to the generation of less plastic waste. PRACTICAL APPLICATION: The study and application of cryogels, as innovative systems in the food industry, allow to expand and diversify the materials that can function as coatings to maintain some quality characteristics, in this case in bakery products, so it is important to analyze their effects and consider them to improve conservation processes.

"One-stop" synergistic strategy for hepatocellular carcinoma postoperative recurrence

Residual tumor recurrence after surgical resection of hepatocellular carcinoma (HCC) remains a considerable challenge that imperils the prognosis of patients. Notably, intraoperative bleeding and postoperative infection are potential risk factors for tumor recurrence. However, the biomaterial strategy for the above problems has rarely been reported. Herein, a series of cryogels (coded as SQ-n) based on sodium alginate (SA) and quaternized chitosan (QC) were synthesized and selected for optimal ratios. The in vitro assays showed that SQ-50 possessed superior hemostasis, excellent antibacterial property, and great cytocompatibility. Subsequently, SQAP was constructed by loading black phosphorus nanosheets (BPNSs) and anlotinib hydrochloride (AL3818) based on SQ-50. Physicochemical experiments confirmed that near-infrared (NIR)-assisted SQAP could control the release of AL3818 in photothermal response, significantly inhibiting the proliferation and survival of HUVECs and H22 cells. Furthermore, in vivo studies indicated that the NIR-assisted SQAP prevented local recurrence of ectopic HCC after surgical resection, achieved through the synergistic effect of mPTT and molecular targeted therapy. Thus, the multifunctional SQAP provides a "one-stop" synergistic strategy for HCC postoperative recurrence, showing great potential for clinical application.

Regulable preparation of silk fibroin composite cryogel by dual-directional crosslink for achieving self-cleaning, superelasticity and multifunctional water purification

Recently, the cryogel as a special type of hydrogel was widely used in the field of medicine due to its porous structure and good biocompatibilit. However, great challenges existed for its irregular pore size and incompressible property, limiting its application in other fields. In this study, a novel silk fibroin-based cryogel (named SF@PVA/CS) with regulable pore size, excellent elasticity and durability was constructed using a green dual-directional crosslink strategy. The SF@PVA/CS was prepared by using silk fibroin (SF) as bone scaffold, and chitosan (CS) and polyvinyl alcohol (PVA) as polymer hydrogel which was introduced into the inner bone scaffold of SF. Such a brand-new cryogel possessed three-dimensional dual network structure, which can overcome the shortcoming of unregulatable pore size and incompressibility of traditional cryogel. Additionally, the developed SF@PVA/CS membrane was used for water purification for the first time, which exhibited superior selective permeation, excellent anti-fouling and brilliant self-cleaning property, and it can achieve the purification of both oil/water emulsion and methylene blue solution. This study expanded the application of SF-based cryogel, providing a novel routine for designing new-type composite cryogel and widening the application of dual-directional crosslink strategy developed in this study for facilitating the purification of wastewater.

Cryogels: Advancing Biomaterials for Transformative Biomedical Applications

Cryogels, composed of synthetic and natural materials, have emerged as versatile biomaterials with applications in tissue engineering, controlled drug delivery, regenerative medicine, and therapeutics. However, optimizing cryogel properties, such as mechanical strength and release profiles, remains challenging. To advance the field, researchers are exploring advanced manufacturing techniques, biomimetic design, and addressing long-term stability. Combination therapies and drug delivery systems using cryogels show promise. In vivo evaluation and clinical trials are crucial for safety and efficacy. Overcoming practical challenges, including scalability, structural integrity, mass transfer constraints, biocompatibility, seamless integration, and cost-effectiveness, is essential. By addressing these challenges, cryogels can transform biomedical applications with innovative biomaterials.

Tissue Engineering Challenges for Cultivated Meat to Meet the Real Demand of a Global Market

Cultivated meat (CM) technology has the potential to disrupt the food industry-indeed, it is already an inevitable reality. This new technology is an alternative to solve the environmental, health and ethical issues associated with the demand for meat products. The global market longs for biotechnological improvements for the CM production chain. CM, also known as cultured, cell-based, lab-grown, in vitro or clean meat, is obtained through cellular agriculture, which is based on applying tissue engineering principles. In practice, it is first necessary to choose the best cell source and type, and then to furnish the necessary nutrients, growth factors and signalling molecules via cultivation media. This procedure occurs in a controlled environment that provides the surfaces necessary for anchor-dependent cells and offers microcarriers and scaffolds that favour the three-dimensional (3D) organisation of multiple cell types. In this review, we discuss relevant information to CM production, including the cultivation process, cell sources, medium requirements, the main obstacles to CM production (consumer acceptance, scalability, safety and reproducibility), the technological aspects of 3D models (biomaterials, microcarriers and scaffolds) and assembly methods (cell layering, spinning and 3D bioprinting). We also provide an outlook on the global CM market. Our review brings a broad overview of the CM field, providing an update for everyone interested in the topic, which is especially important because CM is a multidisciplinary technology.

Locust Bean Gum, a Vegetable Hydrocolloid with Industrial and Biopharmaceutical Applications

Locust bean gum (LBG), a vegetable galactomannan extracted from carob tree seeds, is extensively used in the food industry as a thickening agent (E410). Its molecular conformation in aqueous solutions determines its solubility and rheological performance. LBG is an interesting polysaccharide also because of its synergistic behavior with other biopolymers (xanthan gum, carrageenan, etc.). In addition, this hydrocolloid is easily modified by derivatization or crosslinking. These LBG-related products, besides their applications in the food industry, can be used as encapsulation and drug delivery devices, packaging materials, batteries, and catalyst supports, among other biopharmaceutical and industrial uses. As the new derivatized or crosslinked polymers based on LBG are mainly biodegradable and non-toxic, the use of this polysaccharide (by itself or combined with other biopolymers) will contribute to generating greener products, considering the origin of raw materials used, the modification procedures selected and the final destination of the products.

Recent Advances in Macroporous Hydrogels for Cell Behavior and Tissue Engineering

Hydrogels have been extensively used as scaffolds in tissue engineering for cell adhesion, proliferation, migration, and differentiation because of their high-water content and biocompatibility similarity to the extracellular matrix. However, submicron or nanosized pore networks within hydrogels severely limit cell survival and tissue regeneration. In recent years, the application of macroporous hydrogels in tissue engineering has received considerable attention. The macroporous structure not only facilitates nutrient transportation and metabolite discharge but also provides more space for cell behavior and tissue formation. Several strategies for creating and functionalizing macroporous hydrogels have been reported. This review began with an overview of the advantages and challenges of macroporous hydrogels in the regulation of cellular behavior. In addition, advanced methods for the preparation of macroporous hydrogels to modulate cellular behavior were discussed. Finally, future research in related fields was discussed.

Recent Advances in Polysaccharide-Based Physical Hydrogels and Their Potential Applications for Biomedical and Wastewater Treatment

Polysaccharides have been widely employed to fabricate hydrogels owing to their intrinsic properties including biocompatibility, biodegradability, sustainability, and easy modification. However, a considerable amount of polysaccharide-based hydrogels are prepared by chemical crosslinking method using organic solvents or toxic crosslinkers. The presence of reaction by-products and residual toxic substances in the obtained materials cause a potential secondary pollution risk and thus severely limited their practical applications. In contrast, polysaccharide-based physical hydrogels are preferred over chemically derived hydrogels and can be used to address existing drawbacks of chemical hydrogels. The polysaccharide chains of such hydrogel are typically crosslinked by dynamic non-covalent bonds, and the co-existence of multiple physical interactions stabilize the hydrogel network. This review focuses on providing a detailed outlook for the design strategies and formation mechanisms of polysaccharide-based physical hydrogels as well as their specific applications in tissue engineering, drug delivery, wound healing, and wastewater treatment. The main preparation principles, future challenges, and potential improvements are also outlined. The authors hope that this review could provide valuable information for the rational fabrication of polysaccharide-based physical hydrogel. The specific research works listed in the review will provide a systematic and solid research basis for the reliable development of polysaccharide-based physical hydrogel. This article is protected by copyright. All rights reserved.

Scaffolds for Cultured Meat on the Basis of Polysaccharide Hydrogels Enriched with Plant-Based Proteins

The world population is growing and alternative ways of satisfying the increasing demand for meat are being explored, such as using animal cells for the fabrication of cultured meat. Edible biomaterials are required as supporting structures. Hence, we chose agarose, gellan and a xanthan-locust bean gum blend (XLB) as support materials with pea and soy protein additives and analyzed them regarding material properties and biocompatibility. We successfully built stable hydrogels containing up to 1% pea or soy protein. Higher amounts of protein resulted in poor handling properties and unstable gels. The gelation temperature range for agarose and gellan blends is between 23-30 °C, but for XLB blends it is above 55 °C. A change in viscosity and a decrease in the swelling behavior was observed in the polysaccharide-protein gels compared to the pure polysaccharide gels. None of the leachates of the investigated materials had cytotoxic effects on the myoblast cell line C2C12. All polysaccharide-protein blends evaluated turned out as potential candidates for cultured meat. For cell-laden gels, the gellan blends were the most suitable in terms of processing and uniform distribution of cells, followed by agarose blends, whereas no stable cell-laden gels could be formed with XLB blends.