3D Bioprinting of a Bioactive Composite Scaffold for Cell Delivery in Periodontal Tissue Regeneration

3D Bioprinting: Shaping the Future of Periodontal Tissue Regeneration and Disease Management

The periodontium is one of the most complex tissues in the body, consisting of a hierarchical blend of soft and hard tissues. Its complex architecture makes treating and regenerating disease-damaged periodontal tissues a persistent challenge in biomedicine. Three-dimensional (3D) bioprinting represents a transformative approach to tissue engineering, offering promising advancements in treating and regenerating periodontal disease. This innovative technology enables the precise fabrication of complex, patient-specific tissue structures, facilitating the repair and restoration of damaged periodontal tissues, including the gingiva, bone, and periodontal ligament (PDL). By utilizing biocompatible materials such as living cells, hydrogels, and growth factors, 3D bioprinting has the potential to create functional, biologically integrated constructs that can mimic the natural architecture of periodontal tissues. However, translating these advancements into clinical applications remains a challenge. Emerging technologies like bioprinting have been developed to address some limitations of traditional tissue engineering methods. This review explores the current state of 3D bioprinting technology, its application in periodontal disease treatment, and the challenges associated with scaling up this technology for clinical use. Additionally, it discusses the future implications of bioprinting for personalized medicine, offering a new frontier for regenerating periodontal tissues and improving patient outcomes in oral health. Integrating 3D bioprinting into periodontal regenerative therapies could revolutionize clinical practices, offering more effective, tailored, and sustainable solutions to address the challenges of periodontal disease.

Classification and bibliometric analysis of hydrogels in periodontitis treatment: Trends, mechanisms, advantages, and future research directions

OBJECTIVES

The review assess the potential of hydrogel-based drug delivery systems in treating periodontitis. Hydrogels are classified based on source, composition, configuration, crosslinking methods, ionic charge, and response to stimuli.

METHODS

The methodology comprised of comprehensive data collection from WoS, Scopus and PubMed databases covering the period of 2004-2024 of 626 documents. A bibliometric analysis was conducted using VOS Viewer to identify research trends, key contributors, prominent topics, and leading journals. A comparative analysis was performed to examine the benefits of hydrogels over conventional periodontitis treatments. Current research and innovations in hydrogel formulations were reviewed, including ongoing clinical trials and commercial products.

RESULTS

China was found to be the leading contributor to hydrogel research in periodontitis, with key topics including "hydrogels," "nanoparticles," and "drug delivery." A detailed classification system for hydrogels was established, aiding in their application for targeted drug delivery and tissue regeneration. Hydrogels were found to offer controlled drug release, support for tissue regeneration, and improved clinical outcomes compared to traditional treatments. Innovations highlighted including the use of various polymers like nano-hydroxyapatite/collagen composites, PLGA-based materials, and chitosan gels in clinical trials, demonstrating enhanced cell proliferation and tissue regeneration.

SIGNIFICANCE

This review underscores the significant potential of hydrogel-based therapies in advancing the treatment of periodontitis. By providing a comprehensive bibliometric analysis and highlighting key research and innovations, it emphasizes the advantages of hydrogels in terms of targeted drug delivery, minimal invasiveness, and support for tissue regeneration. The findings suggest that with further clinical trials and regulatory approvals, hydrogels could become a mainstream, effective treatment option for periodontitis, offering improved patient outcomes and potentially transforming periodontal therapy.

A Comprehensive Literature Review on Advancements and Challenges in 3D Bioprinting of Human Organs: Ear, Skin, and Bone

The field of 3D bioprinting is rapidly emerging within the realm of regenerative medicine, offering significant potential in dealing with the issue of organ shortages. Despite being in its early stages, it has the potential to replicate tissue structures accurately, providing new potential solutions for reconstructive surgery. This review explores the diverse applications of 3D bioprinting in regenerative medicine, pharmaceuticals, and the food industry, specifically focusing on ear, skin, and bone tissues due to their unique challenges and implications in the field. Significant progress has been made in cartilage and bone scaffold fabrication in ear reconstruction, yet challenges in functional maturation persist. Recent advancements highlight the potential for patient-specific ear substitutes, emphasizing the need for extensive clinical trials. In skin regeneration, 3D bioprinting addresses limitations in existing models, offering opportunities for improved wound healing and realistic skin models. While challenges exist, progress in biomaterials and in-situ bioprinting holds promise. In bone regeneration, 3D bioprinting presents personalized solutions for defects, but scaffold design refinement and addressing regulatory and ethical considerations are crucial. The transformative potential of 3D bioprinting in the field of medicine holds the promise of redefining therapeutic approaches and delivering personalized treatments and functional tissues. Interdisciplinary collaboration is essential for fully realizing the capabilities of 3D bioprinting. This review provides a detailed analysis of current methodologies, challenges, and prospects in 3D bioprinting for ear, skin, and bone tissue regeneration.

Hydrogels in Alveolar Bone Regeneration

Alveolar bone defects caused by oral trauma, alveolar fenestration, periodontal disease, and congenital malformations can severely affect oral function and facial aesthetics. Despite the successful clinical applications of bone grafts or bone substitutes, optimal alveolar bone regeneration continues to be challenging due to the complex oral environment and its unique physiological functions. Hydrogels that serve as promising candidates for tissue regeneration are under development to meet the specific needs for increased bone regeneration capacity and improved operational efficiency in alveolar bone repair. In this review, we emphasize the considerations in hydrogel design for alveolar bone regeneration and summarize the latest applications of hydrogels in prevalent clinical diseases related to alveolar bone defects. The future perspectives and challenges for the application of hydrogels in the field of alveolar bone regeneration are also discussed. Deepening our understanding of these biomaterials will facilitate the advent of novel inventions to improve the outcome of alveolar bone tissue regeneration.

Optimizing collagen-based biomaterials for periodontal regeneration: clinical opportunities and challenges

Periodontal disease (PD) is a chronic inflammatory condition that affects the teeth and their supporting tissues, ultimately culminating in tooth loss. Currently, treatment modalities, such as systemic and local administration of antibiotics, serve to mitigate the progression of inflammation yet fall short in restoring the original anatomical structure and physiological function of periodontal tissues. Biocompatible material-based tissue engineering seems to be a promising therapeutic strategy for treating PD. Collagen, a component of the extracellular matrix commonly used for tissue engineering, has been regarded as a promising biogenic material for tissue regeneration owing to its high cell-activating and biocompatible properties. The structural and chemical similarities between collagen and components of the oral tissue extracellular matrix render it a promising candidate for dental regeneration. This review explored the properties of collagen and its current applications in periodontal regeneration. We also discussed the recent progression in collagen therapies and preparation techniques. The review also scrutinizes the pros and cons associated with the application of collagen-based biomaterials in PD treatment, aiming to pave the way for future applications of collagen-based biomaterials in the management of PD.

Biomedical Application of Enzymatically Crosslinked Injectable Hydrogels

Hydrogels have garnered significant interest in the biomedical field owing to their tissue-like properties and capability to incorporate various fillers. Among these, injectable hydrogels have been highlighted for their unique advantages, especially their minimally invasive administration mode for implantable use. These injectable hydrogels can be utilized in their pristine forms or as composites by integrating them with therapeutic filler materials. Given their primary application in implantable platforms, enzymatically crosslinked injectable hydrogels have been actively explored due to their excellent biocompatibility and easily controllable mechanical properties for the desired use. This review introduces the crosslinking mechanisms of such hydrogels, focusing on those mediated by horseradish peroxidase (HRP), transglutaminase (TG), and tyrosinase. Furthermore, several parameters and their relationships with the intrinsic properties of hydrogels are investigated. Subsequently, the representative biomedical applications of enzymatically crosslinked-injectable hydrogels are presented, including those for wound healing, preventing post-operative adhesion (POA), and hemostasis. Furthermore, hydrogel composites containing filler materials, such as therapeutic cells, proteins, and drugs, are analyzed. In conclusion, we examine the scientific challenges and directions for future developments in the field of enzymatically crosslinked-injectable hydrogels, focusing on material selection, intrinsic properties, and filler integration.

Biomaterial Scaffolds for Periodontal Tissue Engineering

Advanced periodontitis poses a significant threat to oral health, causing extensive damage and loss of both hard and soft periodontal tissues. While traditional therapies such as scaling and root planing can effectively halt the disease's progression, they often fail to fully restore the original architecture and function of periodontal tissues due to the limited capacity for spontaneous regeneration. To address this challenge, periodontal tissue engineering has emerged as a promising approach. This technology centers on the utilization of biomaterial scaffolds, which function as three-dimensional (3D) templates or frameworks, supporting and guiding the regeneration of periodontal tissues, including the periodontal ligament, cementum, alveolar bone, and gingival tissue. These scaffolds mimic the extracellular matrix (ECM) of native periodontal tissues, aiming to foster cell attachment, proliferation, differentiation, and, ultimately, the formation of new, functional periodontal structures. Despite the inherent challenges associated with preclinical testing, the intensification of research on biomaterial scaffolds, coupled with the continuous advancement of fabrication technology, leads us to anticipate a significant expansion in their application for periodontal tissue regeneration. This review comprehensively covers the recent advancements in biomaterial scaffolds engineered specifically for periodontal tissue regeneration, aiming to provide insights into the current state of the field and potential directions for future research.

3D Bioprinting Techniques and Bioinks for Periodontal Tissues Regeneration-A Literature Review

The periodontal tissue is made up of supporting tissues and among its functions, it promotes viscoelastic properties, proprioceptive sensors, and dental anchorage. Its progressive destruction by disease leads to the loss of bone and periodontal ligaments. For this reason, biomaterials are constantly being developed to restore tissue function. Various techniques are being used to promote regenerative dentistry, including 3D bioprinting with bioink formulations. This paper aims to review the different types of bioink formulations and 3D bioprinting techniques used in periodontal tissue regeneration. Different techniques have been formulated, and the addition of different materials into bioinks has been conducted, with the intention of improving the process and creating a bioink that supports cell viability, proliferation, differentiation, and stability for periodontal tissue regeneration.

Alginate-Based Electrospun Nanofibers and the Enabled Drug Controlled Release Profiles: A Review

Alginate is a natural polymer with good biocompatible properties and is a potential polymeric material for the sustainable development and replacement of petroleum derivatives. However, the non-spinnability of pure alginate solutions has hindered the expansion of alginate applications. With the continuous development of electrospinning technology, synthetic polymers, such as PEO and PVA, are used as co-spinning agents to increase the spinnability of alginate. Moreover, the coaxial, parallel Janus, tertiary and other diverse and novel electrospun fiber structures prepared by multi-fluid electrospinning have found a new breakthrough for the problem of poor spinning of natural polymers. Meanwhile, the diverse electrospun fiber structures effectively achieve multiple release modes of drugs. The powerful combination of alginate and electrostatic spinning is widely used in many biomedical fields, such as tissue engineering, regenerative engineering, bioscaffolds, and drug delivery, and the research fever continues to climb. This is particularly true for the controlled delivery aspect of drugs. This review provides a brief overview of alginate, introduces new advances in electrostatic spinning, and highlights the research progress of alginate-based electrospun nanofibers in achieving various controlled release modes, such as pulsed release, sustained release, biphasic release, responsive release, and targeted release.

The 3-dimensional printing for dental tissue regeneration: the state of the art and future challenges

Tooth loss or damage poses great threaten to oral and general health. While contemporary clinical treatments have enabled tooth restoration to a certain extent, achieving functional tooth regeneration remains a challenging task due to the intricate and hierarchically organized architecture of teeth. The past few decades have seen a rapid development of three-dimensional (3D) printing technology, which has provided new breakthroughs in the field of tissue engineering and regenerative dentistry. This review outlined the bioactive materials and stem/progenitor cells used in dental regeneration, summarized recent advancements in the application of 3D printing technology for tooth and tooth-supporting tissue regeneration, including dental pulp, dentin, periodontal ligament, alveolar bone and so on. It also discussed current obstacles and potential future directions, aiming to inspire innovative ideas and encourage further development in regenerative medicine.

Biomaterials regulates BMSCs differentiation via mechanical microenvironment

Bone mesenchymal stem cells (BMSCs) are crucial for bone tissue regeneration, the mechanical microenvironment of hard tissues, including bone and teeth, significantly affects the osteogenic differentiation of BMSCs. Biomaterials may mimic the microenvironment of the extracellular matrix and provide mechanical signals to regulate BMSCs differentiation via inducing the secretion of various intracellular factors. Biomaterials direct the differentiation of BMSCs via mechanical signals, including tension, compression, shear, hydrostatic pressure, stiffness, elasticity, and viscoelasticity, which can be transmitted to cells through mechanical signalling pathways. Besides, biomaterials with piezoelectric effects regulate BMSCs differentiation via indirect mechanical signals, such as, electronic signals, which are transformed from mechanical stimuli by piezoelectric biomaterials. Mechanical stimulation facilitates achieving vectored stem cell fate regulation, while understanding the underlying mechanisms remains challenging. Herein, this review summarizes the intracellular factors, including translation factors, epigenetic modifications, and miRNA level, as well as the extracellular factor, including direct and indirect mechanical signals, which regulate the osteogenic differentiation of BMSCs. Besides, this review will also give a comprehensive summary about how mechanical stimuli regulate cellular behaviours, as well as how biomaterials promote the osteogenic differentiation of BMSCs via mechanical microenvironments. The cellular behaviours and activated signal pathways will give more implications for the design of biomaterials with superior properties for bone tissue engineering. Moreover, it will also provide inspiration for the construction of bone organoids which is a useful tool for mimicking in vivo bone tissue microenvironments.

New Insights in Hydrogels for Periodontal Regeneration

Periodontitis is a destructive inflammatory disease characterized by microbial infection that damages the tissues supporting the tooth (alveolar bone, gingiva, periodontal ligament, and cementum), ultimately resulting in the loss of teeth. The ultimate goal of periodontal therapy is to achieve the regeneration of all of the periodontal tissues. Thus, tissue engineering approaches have been evolving from simple membranes or grafts to more complex constructs. Hydrogels are highly hydrophilic polymeric networks with the ability to simulate the natural microenvironment of cells. In particular, hydrogels offer several advantages when compared to other forms of scaffolds, such as tissue mimicry and sustained drug delivery. Moreover, hydrogels can maintain a moist environment similar to the oral cavity. Hydrogels allow for precise placement and retention of regenerative materials at the defect site, minimizing the potential for off-target effects and ensuring that the treatment is focused on the specific defect site. As a mechanism of action, the sustained release of drugs presented by hydrogels allows for control of the disease by reducing the inflammation and attracting host cells to the defect site. Several therapeutic agents, such as antibiotics, anti-inflammatory and osteogenic drugs, have been loaded into hydrogels, presenting effective benefits in periodontal health and allowing for sustained drug release. This review discusses the causes and consequences of periodontal disease, as well as the advantages and limitations of current treatments applied in clinics. The main components of hydrogels for periodontal regeneration are discussed focusing on their different characteristics, outcomes, and strategies for drug delivery. Novel methods for the fabrication of hydrogels are highlighted, and clinical studies regarding the periodontal applications of hydrogels are reviewed. Finally, limitations in current research are discussed, and potential future directions are proposed.

Advancing Dentistry through Bioprinting: Personalization of Oral Tissues

Despite significant advancements in dental tissue restoration and the use of prostheses for addressing tooth loss, the prevailing clinical approaches remain somewhat inadequate for replicating native dental tissue characteristics. The emergence of three-dimensional (3D) bioprinting offers a promising innovation within the fields of regenerative medicine and tissue engineering. This technology offers notable precision and efficiency, thereby introducing a fresh avenue for tissue regeneration. Unlike the traditional framework encompassing scaffolds, cells, and signaling factors, 3D bioprinting constitutes a contemporary addition to the arsenal of tissue engineering tools. The ongoing shift from conventional dentistry to a more personalized paradigm, principally under the guidance of bioprinting, is poised to exert a significant influence in the foreseeable future. This systematic review undertakes the task of aggregating and analyzing insights related to the application of bioprinting in the context of regenerative dentistry. Adhering to PRISMA guidelines, an exhaustive literature survey spanning the years 2019 to 2023 was performed across prominent databases including PubMed, Scopus, Google Scholar, and ScienceDirect. The landscape of regenerative dentistry has ushered in novel prospects for dentoalveolar treatments and personalized interventions. This review expounds on contemporary accomplishments and avenues for the regeneration of pulp-dentin, bone, periodontal tissues, and gingival tissues. The progressive strides achieved in the realm of bioprinting hold the potential to not only enhance the quality of life but also to catalyze transformative shifts within the domains of medical and dental practices.