Preparation of High Mechanical Strength Chitosan Nanofiber/NanoSiO2/PVA Composite Scaffolds for Bone Tissue Engineering Using Sol-Gel Method

Alginate-containing 3D-printed hydrogel scaffolds incorporated with strontium promotes vascularization and bone regeneration

Bone defects persist as a significant challenge in the field of clinical orthopedics. This study focuses on the fabrication and characterization of 3D-printed composite hydrogel scaffolds composed of sodium alginate, gelatin, and α-tricalcium phosphate (α-TCP) with varying ratios of Strontium ions (Sr2+). These scaffolds aim to address the clinical challenges associated with bone defect repair by providing mechanical support and promoting bone formation and vascularization. The degradation, swelling, mechanical properties, and release profiles of Sr2+ from the hydrogel scaffolds were comprehensively characterized. In vitro tests were conducted to assess cell viability and proliferation, as well as osteogenic and angiogenic gene expression, to investigate the osteogenic and pro-angiogenic potential of the composite hydrogel scaffolds. Furthermore, skull defect simulations were performed, and composite scaffolds with varying Sr2+ ratios were implanted to evaluate their effectiveness in bone repair. This research establishes a foundation for advancing bone tissue engineering through composite scaffolds containing biological macromolecules and strontium, with alginate serving as a key element in enhancing performance and expanding clinical applicability.

Chitosan scaffolds: Expanding horizons in biomedical applications

Chitosan, a natural polysaccharide from chitin, shows promise as a biomaterial for various biomedical applications due to its biocompatibility, biodegradability, antibacterial activity, and ease of modification. This review overviews "chitosan scaffolds" use in diverse biomedical applications. It emphasizes chitosan's structural and biological properties and explores fabrication methods like gelation, electrospinning, and 3D printing, which influence scaffold architecture and mechanical properties. The review focuses on chitosan scaffolds in tissue engineering and regenerative medicine, highlighting their role in bone, cartilage, skin, nerve, and vascular tissue regeneration, supporting cell adhesion, proliferation, and differentiation. Investigations into incorporating bioactive compounds, growth factors, and nanoparticles for improved therapeutic effects are discussed. The review also examines chitosan scaffolds in drug delivery systems, leveraging their prolonged release capabilities and ability to encapsulate medicines for targeted and controlled drug delivery. Moreover, it explores chitosan's antibacterial activity and potential for wound healing and infection management in biomedical contexts. Lastly, the review discusses challenges and future objectives, emphasizing the need for improved scaffold design, mechanical qualities, and understanding of interactions with host tissues. In summary, chitosan scaffolds hold significant potential in various biological applications, and this review underscores their promising role in advancing biomedical science.

Role of Chitosan Hydrogels in Clinical Dentistry

Biopolymers are organic polymers that can be treated into intricate designs with porous characteristics that mimic essential biologic components. Due to their superior biosafety, biodegradability, biocompatibility, etc., they have been utilized immensely in biomedical engineering, regeneration, and drug delivery. To obtain the greatest number of results, a literature search was undertaken in scientific search engines utilizing keywords. Chitosan is used in a variety of medical sectors, with the goal of emphasizing its applications and benefits in the clinical dental industry. Chitosan can be dissolved in liquid form and combined with other substances to create a variety of products, including fibers, hydrogels, membranes, microspheres, resins, sponges, pastes, tablets, and micro granules. Chitosan has been studied in a variety of dental applications. Chitosan is used in the prevention of caries and wear, in pulpotomy to accelerate osteogenesis in guided tissue regeneration due to its hemostatic property, and primarily to benefit from its antimicrobial activity by adding it to materials, such as glass ionomer cement, calcium hydroxide, and adhesive systems. With its antibacterial activity and biocompatibility, chitosan is leading the pack as a promising ingredient in the production of dental materials. The current review provides an update on the background, fundamentals, and wide range of uses of chitosan and its gels in dental science.

Nanofiber Scaffolds as Drug Delivery Systems Promoting Wound Healing

Nanofiber scaffolds have emerged as a revolutionary drug delivery platform for promoting wound healing, due to their unique properties, including high surface area, interconnected porosity, excellent breathability, and moisture absorption, as well as their spatial structure which mimics the extracellular matrix. However, the use of nanofibers to achieve controlled drug loading and release still presents many challenges, with ongoing research still exploring how to load drugs onto nanofiber scaffolds without loss of activity and how to control their release in a specific spatiotemporal manner. This comprehensive study systematically reviews the applications and recent advances related to drug-laden nanofiber scaffolds for skin-wound management. First, we introduce commonly used methods for nanofiber preparation, including electrostatic spinning, sol-gel, molecular self-assembly, thermally induced phase separation, and 3D-printing techniques. Next, we summarize the polymers used in the preparation of nanofibers and drug delivery methods utilizing nanofiber scaffolds. We then review the application of drug-loaded nanofiber scaffolds for wound healing, considering the different stages of wound healing in which the drug acts. Finally, we briefly describe stimulus-responsive drug delivery schemes for nanofiber scaffolds, as well as other exciting drug delivery systems.

Synthesis of Chitosan Oligosaccharide-Loaded Glycyrrhetinic Acid Functionalized Mesoporous Silica Nanoparticles and In Vitro Verification of the Treatment of APAP-Induced Liver Injury

OBJECTIVE

the study was to find a suitable treatment for acute drug-induced liver injury. The use of nanocarriers can improve the therapeutic effect of natural drugs by targeting hepatocytes and higher loads.

METHODS

firstly, uniformly dispersed three-dimensional dendritic mesoporous silica nanospheres (MSNs) were synthesized. Glycyrrhetinic acid (GA) was covalently modified on MSN surfaces through amide bond and then loaded with COSM to form drug-loaded nanoparticles (COSM@MSN-NH₂-GA). The constructed drug-loaded nano-delivery system was determined by characterization analysis. Finally, the effect of nano-drug particles on cell viability was evaluated and the cell uptake in vitro was observed.

RESULTS

GA was successfully modified to obtain the spherical nano-carrier MSN-NH₂-GA (≤200 nm). The neutral surface charge improves its biocompatibility. MSN-NH₂-GA has high drug loading (28.36% ± 1.00) because of its suitable specific surface area and pore volume. In vitro cell experiments showed that COSM@MSN-NH₂-GA significantly enhanced the uptake of liver cells (LO2) and decreased the AST and ALT indexes.

CONCLUSION

this study demonstrated for the first time that formulation and delivery schemes using natural drug COSM and nanocarrier MSN have a protective effect on APAP-induced hepatocyte injury. This result provides a potential nano-delivery scheme for the targeted therapy of acute drug-induced liver injury.

Chitosan-Based Smart Biomaterials for Biomedical Applications: Progress and Perspectives

Over the past decade, smart and functional biomaterials have escalated as one of the most rapidly emerging fields in the life sciences because the performance of biomaterials could be improved by careful consideration of their interaction and response with the living systems. Thus, chitosan could play a crucial role in this frontier field because it possesses many beneficial properties, especially in the biomedical field such as excellent biodegradability, hemostatic properties, antibacterial activity, antioxidant properties, biocompatibility, and low toxicity. Furthermore, chitosan is a smart and versatile biopolymer due to its polycationic nature with reactive functional groups that allow the polymer to form many interesting structures or to be modified in various ways to suit the targeted applications. In this review, we provide an up-to-date development of the versatile structures of chitosan-based smart biomaterials such as nanoparticles, hydrogels, nanofibers, and films, as well as their application in the biomedical field. This review also highlights several strategies to enhance biomaterial performance for fast growing fields in biomedical applications such as drug delivery systems, bone scaffolds, wound healing, and dentistry.

Chitosan-Silica Hybrid Biomaterials for Bone Tissue Engineering: A Comparative Study of Xerogels and Aerogels

Chitosan (CS) is a natural biopolymer that shows promise as a biomaterial for bone-tissue regeneration. However, because of their limited ability to induce cell differentiation and high degradation rate, among other drawbacks associated with its use, the creation of CS-based biomaterials remains a problem in bone tissue engineering research. Here we aimed to reduce these disadvantages while retaining the benefits of potential CS biomaterial by combining it with silica to provide sufficient additional structural support for bone regeneration. In this work, CS-silica xerogel and aerogel hybrids with 8 wt.% CS content, designated SCS8X and SCS8A, respectively, were prepared by sol-gel method, either by direct solvent evaporation at the atmospheric pressure or by supercritical drying in CO₂, respectively. As reported in previous studies, it was confirmed that both types of mesoporous materials exhibited large surface areas (821 m²g^-1-858 m²g^-1) and outstanding bioactivity, as well as osteoconductive properties. In addition to silica and chitosan, the inclusion of 10 wt.% of tricalcium phosphate (TCP), designated SCS8T10X, was also considered, which stimulates a fast bioactive response of the xerogel surface. The results here obtained also demonstrate that xerogels induced earlier cell differentiation than the aerogels with identical composition. In conclusion, our study shows that the sol-gel synthesis of CS-silica xerogels and aerogels enhances not only their bioactive response, but also osteoconduction and cell differentiation properties. Therefore, these new biomaterials should provide adequate secretion of the osteoid for a fast bone regeneration.

Chitosan-Based Scaffolds for Facilitated Endogenous Bone Re-Generation

Facilitated endogenous tissue engineering, as a facile and effective strategy, is emerging for use in bone tissue regeneration. However, the development of bioactive scaffolds with excellent osteo-inductivity to recruit endogenous stem cells homing and differentiation towards lesion areas remains an urgent problem. Chitosan (CS), with versatile qualities including good biocompatibility, biodegradability, and tunable physicochemical and biological properties is undergoing vigorously development in the field of bone repair. Based on this, the review focus on recent advances in chitosan-based scaffolds for facilitated endogenous bone regeneration. Initially, we introduced and compared the facilitated endogenous tissue engineering with traditional tissue engineering. Subsequently, the various CS-based bone repair scaffolds and their fabrication methods were briefly explored. Furthermore, the functional design of CS-based scaffolds in bone endogenous regeneration including biomolecular loading, inorganic nanomaterials hybridization, and physical stimulation was highlighted and discussed. Finally, the major challenges and further research directions of CS-based scaffolds were also elaborated. We hope that this review will provide valuable reference for further bone repair research in the future.