This review highlights the challenges of current wound healing methods, such as scar formation and limited regeneration, and emphasizes the potential of tissue engineering to address these issues. Chitosan, a biopolymer derived from chitin, has garnered significant attention in epidermal-dermal wound healing due to its exceptional biocompatibility, biodegradability, and versatile functional properties. This review article delves into the diverse roles of chitosan, with a particular focus on its use as a scaffold material with fine-tunable physicochemical and biological properties for accelerated wound healing. While bare chitosan provides a suitable microenvironment for cell adhesion and proliferation, it exhibits limited mechanical strength and drug-delivery properties. However, combining it with other natural and synthetic polymers and nanoparticles facilitates drug and biosignal delivery and enhances biocompatibility and antibacterial activity. Furthermore, the review covers various chemical modifications of chitosan, including quaternization and methacrylation, to improve biocompatibility, water solubility and mechanical strength, for developing advanced wound dressings for effective skin regeneration. The review also discusses various types of smart chitosan hydrogels and the clinical translation of chitosan based scaffolds for wound healing and tissue regeneration applications. Finally, it discusses the integration of 3D bioprinting techniques for creating complex, cell-incorporated scaffolds for advanced wound healing therapies.

Mineral nanoparticles and osteoinductive biomaterials are essential in advancing bone regeneration by addressing skeletal conditions and injuries that compromise structural integrity and functionality. These biomaterials stimulate the differentiation of precursor cells into osteoblasts, creating biocompatible environments conducive to bone tissue regeneration. Among the most promising innovations, mineral-based nanoparticles and nanocomposite hydrogels have emerged as effective strategies for enhancing osteoinductive potential. This review explores the diverse types of osteoinductive biomaterials, including natural sources, synthetic compounds, and hybrid designs that incorporate mineralized nanoparticles. Emphasis is placed on polymeric hydrogels as delivery platforms for these materials, highlighting their dual role as structural supports and bioactive agents that promote osteogenesis. Challenges such as immune rejection, biodegradability, mechanical stability, and short in vivo residence time are critically discussed, alongside their impact on clinical translation. By presenting a comprehensive analysis of mechanisms, applications, and limitations, this review identifies opportunities for integrating osteoinductive biomaterials with emerging fields like immunology and biomechanics. Ultimately, this work aims to provide actionable insights and advance the development of novel, clinically relevant solutions that improve patient outcomes and address the growing global need for effective bone repair and regeneration.

A potential solution for prosthetic heart valves is tissue-engineered heart valves. Tissue-engineered heart valves (TEHVs) are designed to replicate the complex properties found in natural tissues, such as stiffness, anisotropy, and composition and organization of cells and extracellular matrix (ECM). Electrospinning is regarded as a highly versatile and innovative approach for fabricating numerous fibrous designs. In this review, we discuss recent developments in electrospun heart valve scaffolds, including scaffold materials, cell types, and electrospinning setups used to prepare aligned nanofibers. Despite the fact that natural biomaterials provided excellent biocompatibility, nanofibers from synthetic materials provided the required mechanical compatibility. Accordingly, most studies highlighted the benefits of designing composite heart valves using biological and synthetic polymers. Various strategies, such as the application of motorized mandrel and micropatterned collector in electrospinning were effective in controlling nanofiber alignment. Studies also showed that aligned nanofiber’s mechanical strength and anisotropic structure promote cell proliferation, and differentiation, and promote attachment. Numerous studies have reported that multiple cell sources are suitable for producing heart valves. Successful results were obtained with human umbilical vein endothelial cells (HUVECs), since they provide a convenient cell source for cellularization of valve leaflets. A higher conductivity of scaffolds was achieved by using biomaterials that conduct electricity, such as polyaniline, polypyrrole, and carbon nanotubes, which resulted in better differentiation of precursor cells to cardiomyocytes and higher cell beating rates. In light of these attributes, nanofibrous scaffolds produced through electrospinning are expected to offer numerous advantages for tissue engineering and medical applications in the near future. However, multiple challenges were identified as cell infiltration and 2D nature of nanofiber mats necessitate further engineering approaches in electrospinning procedure leaflet production.

The design of effective treatments for critical size bone defects, which result from various conditions such as trauma, infection, injury, or tumor resection, presents a significant challenge in clinical practice. While autologous grafts are commonly regarded as gold standard treatments in these complex healing scenarios, they are often associated with notable limitations, including donor site morbidity and limited graft volume. As a result, recent research trends have shifted towards developing biomaterials that better emulate the inherent complexity of the native bone structure and function through implementation of a “Diamond Concept” polytherapy strategy. Central to this approach is the utilization of biomaterials, increasingly composed of composite materials that integrate bioactive osteoinductive factors and cell sources to enhance healing outcomes. The usage of Wnt signaling specific agonists as osteoinductive mediators has been recently shown to be a promising strategy for promoting healing, as this pathway is well established to have an important role in both osteogenic differentiation and bone formation processes. Implementation of a localized delivery system through scaffold incorporation is necessary in this scenario, however, to minimize any potential off-target effects caused by the Wnt signaling cascade’s non-specificity to bone. Findings in the literature clearly show that this approach holds promise to improve clinical healing outcomes, paving the way for more effective treatment options. In this review, we will generally discuss the design of biomaterials, specifically bulk materials and composites, for the treatment of critical size bone defects. Additionally, we will highlight recent work on the design of chitosan-based scaffolds modified with purine crosslinking, to overcome cytotoxicity issues associated with other chemical crosslinkers. In this context, we focus on optimizing material design for this bone healing application and discuss the benefits of localized Wnt agonist as mediators to improve the scaffold’s osteoinductive behavior.