A 6-bromoindirubin-3'-oxime incorporated chitosan-based hydrogel scaffold for potential osteogenic differentiation: Investigation of material properties in vitro

Injecting hope: chitosan hydrogels as bone regeneration innovators

Spontaneous bone regeneration encounters substantial restrictions in cases of bone defects, demanding external intervention to improve the repair and regeneration procedure. The field of bone tissue engineering (BTE), which embraces a range of disciplines, offers compelling replacements for conventional strategies like autografts, allografts, and xenografts. Among the diverse scaffolding materials utilized in BTE applications, hydrogels have demonstrated great promise as templates for the regeneration of bone owing to their resemblance to the innate extracellular matrix. In spite of the advancement of several biomaterials, chitosan (CS), a natural biopolymer, has garnered significant attention in recent years as a beneficial graft material for producing injectable hydrogels. Injectable hydrogels based on CS formulations provide numerous advantages, including their capacity to absorb and preserve a significant amount of water, their minimally invasive character, the existence of porous structures, and their capability to adapt accurately to irregular defects. Moreover, combining CS with other naturally derived or synthetic polymers and bioactive materials has displayed its effectiveness as a feasible substitute for traditional grafts. We aim to spotlight the composition, production, and physicochemical characteristics and practical utilization of CS-based injectable hydrogels, explicitly focusing on their potential implementations in bone regeneration. We consider this review a fundamental resource and a source of inspiration for future research attempts to pioneer the next era of tissue-engineering scaffold materials.

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.

The Diamond Concept Enigma: Recent Trends of Its Implementation in Cross-linked Chitosan-Based Scaffolds for Bone Tissue Engineering

An increasing number of publications over the past ten years have focused on the development of chitosan-based cross-linked scaffolds to regenerate bone tissue. The design of biomaterials for bone tissue engineering applications relies heavily on the ideals set forth by a polytherapy approach called the "Diamond Concept". This methodology takes into consideration the mechanical environment, scaffold properties, osteogenic and angiogenic potential of cells, and benefits of osteoinductive mediator encapsulation. The following review presents a comprehensive summarization of recent trends in chitosan-based cross-linked scaffold development within the scope of the Diamond Concept, particularly for nonload-bearing bone repair. A standardized methodology for material characterization, along with assessment of in vitro and in vivo potential for bone regeneration, is presented based on approaches in the literature, and future directions of the field are discussed.

High-Content Aloe vera Based Hydrogels: Physicochemical and Pharmaceutical Properties

The present research focuses on the physicochemical and pharmacotechnical properties of new hydrogels obtained using allantoin, xanthan gum, salicylic acid and different concentrations of Aloe vera (5, 10, 20% w/v in solution; 38, 56, 71 wt% in dry gels). The thermal behavior of Aloe vera composite hydrogels was studied using DSC and TG/DTG analyses. The chemical structure was investigated using different characterization methods (XRD, FTIR and Raman spectroscopies) and the morphology of the hydrogels was studied SEM and AFM microscopy. Pharmacotechnical evaluation on tensile strength and elongation, moisture content, swelling and spreadability was also completed. Physical evaluation confirmed that the appearance of the prepared Aloe vera based hydrogels was homogeneous and the color varied from pale beige to deep opaque beige with increasing Aloe vera concentration. All other evaluation parameters, e.g., pH, viscosity, spreadability and consistency were found to be adequate in all hydrogel formulations. SEM and AFM images show that the structure of the hydrogels condensed into homogeneous polymeric solids with the addition of Aloe vera, in accordance with the decrease in peak intensities observed via XRD analysis. These results suggest interactions between the hydrogel matrix and Aloe vera as observed via FTIR and TG/DTG and DSC analyses. Considering that Aloe vera content higher than 10% (w/v) did not stimulate further interactions, this formulation (FA-10) can be used for further biomedical applications.