Extracellular Matrix-Based and Extracellular Matrix-Bioinspired Scaffolds for Extracellular Vesicle Delivery in Dental Pulp Regeneration: A Narrative Review

Applications of extracellular vesicles in tissue regeneration: a narrative review

Extracellular vesicles (EVs) are nanoscale, membrane-bound particles released by most cell types and play essential roles in intercellular communication. By transporting proteins, lipids, and nucleic acids, they regulate inflammation, angiogenesis, immune responses, and tissue regeneration. Their biocompatibility and ability to deliver targeted molecular cargo make them promising diagnostic and therapeutic tools. In dentistry, EVs support periodontal repair, dentin–pulp regeneration, bone healing, and implant integration. They are also valuable as salivary biomarkers for oral and systemic diseases. Beyond dentistry, EVs are being explored in oncology, cardiovascular repair, neurology, and regenerative medicine as versatile cell-free therapeutic platforms. This review provides a comprehensive overview of the biology, biogenesis, physiological functions, and mechanisms of action of extracellular vesicles, with a particular focus on their emerging applications in tissue regeneration. A literature search was conducted using PubMed and Google Scholar databases for studies published between 2010 and 2025. Original research articles, review papers, and relevant book chapters published in English were included. EVs have emerged as powerful cell-free mediators of regeneration, capable of orchestrating osteogenesis, angiogenesis, immunomodulation, and tissue repair across maxillofacial structures. Their diverse cargo of miRNAs, proteins, and growth factors enables precise modulation of cellular signaling pathways essential for healing. Current evidence highlights their promising applications in periodontal, pulp–dentin, and craniofacial bone regeneration, as well as their diagnostic value through salivary biomarkers. Continued advancements in EVs standardization, large-scale production, and clinical translation will be critical for integrating EVs-based therapies into future regenerative dentistry and maxillofacial medicine.

Hydrogel Implementing Drug Delivery in Cranial Bone Tissue Engineering

Cranial bone defects remain a significant clinical challenge due to their limited intrinsic regenerative capacity and the complexity of coordinating osteogenesis, angiogenesis, and immune responses within a confined and poorly vascularised environment. Conventional approaches, including autologous grafts and synthetic implants, provide structural support but fail to actively modulate the biological processes required for effective bone regeneration. In this context, hydrogel-based systems have emerged as versatile platforms for localized and controlled drug delivery in cranial bone tissue engineering (BTE). This review provides a comprehensive overview of hydrogel-based delivery strategies designed to regulate the spatiotemporal presentation of bioactive agents within cranial defects. The main classes of hydrogels, natural, synthetic, semi-synthetic, and hybrid systems, are discussed in relation to their physicochemical properties and suitability for drug delivery applications. Current delivery approaches are analysed, including cell-free systems (growth factors, peptides, bioactive ions, nucleic acids, and small molecules drugs), cell-based platforms, and multifunctional systems integrating secondary carriers such as nanoparticles (NPs), microparticles (MPs), and extracellular vesicles (EVs). Particular emphasis is placed on how hydrogel design parameters, including crosslinking density, degradation kinetics, and responsiveness to microenvironmental cues, govern therapeutic release and influence regenerative outcomes. Emerging strategies and key translational challenges are also highlighted.

Biochemical and Physicomechanical Cues of Biomaterials Guide Osteogenic Differentiation of Mesenchymal Stem Cells

Bone regeneration remains a significant clinical challenge, particularly for large or critical-sized defects caused by trauma, disease, or congenital abnormalities. Mesenchymal stem cells (MSCs) have emerged as a promising cell source for bone tissue engineering, with their osteogenic differentiation playing a crucial role in bone repair. Biomaterials serve as scaffolds that facilitate MSC-mediated bone regeneration by providing structural support and mimicking the extracellular matrix (ECM). This review explores recent advancements in biomaterials designed to promote MSC osteogenesis through two primary approaches: biochemical and physicomechanical stimuli. Therapeutic agent-loaded scaffolds, incorporating growth factors, small molecules, gene materials, peptides, proteins, and extracellular vesicles (EVs), have been extensively studied for their ability to enhance osteogenic differentiation. However, concerns regarding toxicity, off-target effects, and regulatory limitations have led to increasing interest in biomaterials that utilize physicomechanical cues such as stiffness, viscoelasticity, topography, porosity, and dynamic forces (shear stress, compression, vibration) as alternative or complementary strategies. Furthermore, the synergistic effects of multiple physicomechanical cues are being explored to regulate MSC behavior for promoting bone regeneration. This review discusses current challenges, emerging trends, and future directions in the development of next-generation biomaterials that integrate biochemical and physicomechanical approaches for clinical applications in bone repair and regeneration.

Tissue regeneration strategies based on mesenchymal stem cell-derived extracellular vesicles: from bench to bedside

Abstract Regenerative medicine is undergoing a paradigm shift from live-cell therapies to cell-free strategies. Within this evolving field, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as a leading platform. These nanoscale vesicles deliver bioactive cargo that mediates critical therapeutic functions, including immunomodulation, angiogenesis, and anti-fibrosis. Furthermore, they offer improved safety, greater potential for standardization, and enhanced scalability compared to traditional live-cell therapies. However, clinical translation remains constrained by several challenges, such as inherent vesicle heterogeneity, limited targeting specificity, and bottlenecks in large-scale manufacturing. This review systematically examines the biogenesis of MSC-EVs, focusing specifically on exosomes, microvesicles, and apoptotic vesicles. We evaluate their functional performance across diverse regeneration contexts, encompassing orofacial, barrier, musculoskeletal, and visceral tissue regeneration. We further highlight innovative engineering strategies designed to enhance therapeutic efficacy, such as surface modification, cargo loading, and biomaterial-integrated delivery systems. In addition, we introduce an emerging approach utilizing engineered MSC aggregate-derived EVs inspired by organ morphogenesis. Finally, this article details the strategic framework required for clinical translation. The framework encompasses scalable production, rigorous quality control, comprehensive non-clinical studies, evolving regulatory pathways, and the current clinical trial landscape. Collectively, this work provides an integrated roadmap for advancing MSC-EVs as a next-generation precision platform for cell-free therapeutics.

Engineered Extracellular Vesicles for Cartilage Regeneration: Bridging Biological Complexity to Clinical Precision

Osteoarthritis (OA) is a common degenerative joint disease characterized by pain, stiffness, progressive cartilage loss, and reduced mobility. Current treatments primarily aim to relieve symptoms rather than restore damaged cartilage, and durable regeneration of native hyaline cartilage remains a major clinical challenge. Extracellular Vesicles (EVs), particularly those derived from Mesenchymal Stem Cells (MSCs), have emerged as promising cell-free therapeutic platforms because of their ability to modulate inflammation, regulate chondrocyte activity, and influence extracellular matrix metabolism. However, EV heterogeneity, source-dependent variability, limited targeting efficiency, inconsistent cargo loading, and lack of standardized manufacturing protocols continue to restrict their clinical translation. This review summarizes recent advances in engineered EV-based strategies for OA and cartilage repair, including parental-cell preconditioning, genetic modification, surface functionalization, cargo loading, artificial EV platforms, and biomaterial-assisted delivery. Importantly, we distinguish between in vitro findings, preclinical animal studies, and early clinical evidence to provide a balanced assessment of translational readiness. We also discuss key regulatory and safety challenges, including GMP-compliant production, batch-to-batch variability, quality-control criteria, potency assays, scalability, biodistribution, and long-term safety. By integrating EV engineering with translational and regulatory perspectives, this review highlights the potential of engineered EVs as future disease-modifying tools for OA while emphasizing that their clinical efficacy and capacity to restore durable hyaline cartilage remain to be demonstrated in robust human studies. 

Dental Pulp Regeneration: A Comprehensive Review of Stem Cells, Biomaterials, and Bioactive Cues.