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.

Silver iodide (AgI) nanostructures have been considered as promising candidates for optical biosensors owing to their optical characteristics of optical properties, including tunable surface plasmon resonance (SPR) and fluorescence enhancement. Such properties let one analyze biomolecules with high sensitivity, which makes them ultra-useful in diagnostics. The formed AgI nanostructures can be synthesized using chemical precipitation and template methods that enable fine-tuning of the morphology and crystallinity of the final nanostructure. The presence of SPR enhances optical signals potentially, and fluorescence enhancement helps visualize biomolecule interactions easier as the analyte concentration is usually low. Such uses of biosensors include applications in proteins, nucleic acids, and other biomolecules for progress in disease diagnosis and pharmacogenomics. Moreover, the good biocompatibility level of the created AgI nanostructures makes it possible to integrate them into biological systems safely, increasing their usage in medicine. This integration of their appealing optics, biosensing operating principles, and biocompatibility establishes their centrality in the creation of future photonic biosensors for faster, intuitive, and painless detection.

Nanoparticles (NPs) are at the forefront as they are providing unprecedented solutions to obstacles and issues in treating neurodegenerative diseases. Due to their size, surface characteristics, and ability to be functionalized, these carriers can directly deliver therapeutics across what is considered one of the main barriers to central nervous system (CNS) treatment, the blood-brain barrier (BBB). Through nano-technology, anti-disease agents such as Alzheimer’s, Parkinson’s, and Huntington’s therapies become more bioavailable, specific in action, and with fewer side effects. The NPs serve as molecular carriers that facilitate transport across the BBB by receptor-mediated transcytosis or by disruption of the barrier with a view to properly delivering drugs to the neural tissues. Some of the therapeutic applications of nanotechnology also present the concept of molecular medicine since the NPs are designed to deliver drugs in accordance with specific biomolecule signals. Besides the therapeutic applications, NPs replace the traditional contrast media for magnetic resonance imaging (MRI) and positron emission tomography (PET) scans for better diagnosis as well as disease tracking in the early stages. In addition, their effects on solubility increase the therapeutic potential of earlier useless compounds, and the preservation of bioactive molecules from degradation increases the therapeutic capacity of medications. Neurodegenerative disorders are marked by oxidative stress and inflammation that contribute to the disease severity; thus, liposomes, dendrimers, and polymeric NPs encapsulate antioxidants and anti-inflammatory compounds, so they target the areas most affected by the disease. Such sophisticated systems minimize the extension of neuronal deterioration and enhance the lot of such patients. The “theranostic” NPs allow for continuous diagnosis and treatment by containing both diagnostic and therapeutic features. These have created unprecedented opportunities to meet the unmet needs in CNS disorders and may revolutionize the evolution of managing neurodegenerative diseases and innovative neuroimaging procedures in the future.

Hydrogel-based drug delivery systems (DDS) offer promising alternatives for treating ocular diseases by overcoming the limitations of traditional therapies, such as low bioavailability, frequent administration, and invasiveness. Hydrogels, with their high biocompatibility and ability to respond to external stimuli, can provide sustained and targeted drug delivery. This review highlights the unique properties of hydrogels, including their swelling behavior, porosity, and mechanical strength, making them suitable for various ocular applications. The classification of hydrogels based on cross-linking methods, origins, and stimuli responsiveness is discussed, emphasizing their potential in drug delivery for dry eye disease (DED), glaucoma, corneal alkali burns, and neovascularization. Notable advances include thermosensitive and pH-responsive hydrogels, which have shown promising results in preclinical studies. Despite these advances, most studies are still in preclinical stages, highlighting the need for rigorous human trials to validate the safety and efficacy of hydrogel DDS. Collaborative efforts among researchers, pharmacologists, and ophthalmologists are essential to translating these innovations into clinical practice, ultimately improving patient outcomes in ocular disease management.

The fusion of biomaterial science with clinical practice in oculoplastic and orbital surgery, particularly in the reconstruction of the posterior lamella of the eyelid, the lacrimal system, orbital floor fractures, and the development of implants for anophthalmic sockets, represents a frontier where materials meet surgical techniques. This review, which spans research from 2015 to 2023, delves into the application and integration of biopolymers and functional biomaterials in these complex areas. The discussion begins by reviewing the key anatomy of the external ocular surface, lacrimal system, and orbit. It then summarizes the various current surgical approaches for treating diseases affecting the external ocular surface and orbital involvement, with an emphasis on the associated challenges. The discussion continues with a comprehensive overview of the advantages and disadvantages of current and emerging biomaterials, including synthetic and natural polymers, used in reconstructive surgeries. These include applications for eyelid structure reconstruction, lacrimal system repair, orbital bone fracture repair, and orbital socket reconstruction. Throughout the review, the pathophysiology and challenges associated with these reconstructive procedures are explored, with an emphasis on surgical nuances and the ongoing pursuit of optimal reconstruction techniques. Finally, this review serves as a valuable resource for familiarizing clinicians with current knowledge and generating future hypotheses. It concludes that no evidence-based guidelines currently exist in oculoplastic surgery regarding the use of biopolymers in reconstructive procedures. Further research is needed to evaluate the efficacy and reproducibility of these biopolymers.

Improving the performance of blood-contacting medical implants is a global health necessity aimed at reducing mortality and morbidity in patients with cardiovascular diseases. Surface modification of the biomaterials from which the vascular grafts are constructed has been used to reduce the risk of complications such as thrombosis and infection. Herein with a focus on vascular tissue engineering, we provided an overview of (a) fundamental hemodynamic considerations for blood-contacting biomaterials, (b) surface modification strategies to attenuate nonspecific adhesion of proteins, improve hemocompatibility, and induce the formation of a confluent endothelial lining, and (c) the guidelines for the clinical development of surface modified biomaterials.