DLP 3D printing of high-resolution root scaffold with bionic bioactivity and biomechanics for personalized bio-root regeneration

Advances in Digital Light Processing (DLP) Bioprinting: A Review of Biomaterials and Its Applications, Innovations, Challenges, and Future Perspectives

Digital light processing (DLP) technology stands out as a groundbreaking method in the field of biomedical engineering that enables the production of highly precise structures using photopolymerizable materials. Smart materials such as shape memory polymers, hydrogels, and nanocomposites are used as ideal materials for personalized medicine applications thanks to their properties such as superior mechanical strength, biocompatibility, and sensitivity to environmental stimuli in DLP technology. The integration of these materials with DLP enables the production of functional and complex structures, especially in areas such as bone and soft tissue engineering, drug delivery, and biosensor production. However, limited material diversity, scalability problems in production processes, and technical difficulties in optimizing bioprinting parameters are among the main obstacles in this field. This study systematically examines the role of smart biomaterials in DLP-based bioprinting processes. It addresses the innovative applications of these materials in tissue engineering and regenerative medicine. It also comprehensively evaluates its contributions to biomedical applications and discusses future research areas to overcome current limitations.

Current Topics in Dental Follicle Cell Research

Dental follicle cells (DFCs) are dental stem cells that can only be obtained from tooth germs or after extraction of unerupted wisdom teeth. For many years, DFCs have been studied in basic research and preclinical studies in regenerative dentistry, as they are involved in both the development of the periodontium and tooth eruption. Since the first isolation, the number of studies with DFCs has increased. This article summarizes the most important articles of the last five years to provide an overview of current research topics. The focus was on basic research and preclinical research. Basic research includes articles on tooth development and tooth eruption, as well as research into molecular mechanisms during osteogenic differentiation. In addition, articles on preclinical research with DFCs focused on regenerative therapies and immunotherapies are also discussed. These new studies show that DFCs have improved our understanding of periodontal development and regeneration. DFC research is important for the regenerative dentistry of the future; however, preclinical studies indicate that significant progress is still needed before DFCs can be integrated into routine clinical practice.

Vat-Based 3D-Bioprinted Scaffolds from Photocurable Bacterial Levan for Osteogenesis and Immunomodulation

Emerging techniques of additive manufacturing, such as vat-based three-dimensional (3D) bioprinting, offer novel routes to prepare personalized scaffolds of complex geometries. However, there is a need to develop bioinks suitable for clinical translation. This study explored the potential of bacterial-sourced methacrylate levan (LeMA) as a bioink for the digital light processing (DLP) 3D bioprinting of bone tissue scaffolds. LeMA was successfully synthesized, characterized, and used to fabricate 3D-bioprinted scaffolds with excellent printability and physicochemical properties. In vitro studies demonstrated superior cytocompatibility of 15% w/v LeMA gels compared to 20% gels. 15% LeMA gels supported osteogenic differentiation , as evidenced by alkaline phosphatase activity and mineral deposition by MC3T3 pre-osteoblasts. Importantly, the LeMA hydrogels positively modulated the macrophage phenotype, promoting the expression of the anti-inflammatory marker CD206. These findings suggest that 3D-printed LeMA scaffolds can create a favorable microenvironment for bone regeneration, highlighting their potential for tissue repair and regeneration applications.

Exploring the Adaptability of 4D Printed Shape Memory Polymer Featuring Dynamic Covalent Bonds

4D printing (4DP) of high-performance shape memory polymers (SMPs), particularly using digital light processing (DLP), has garnered intense global attention due to its capability for rapid and high-precision fabrication of complex configurations, meeting diverse application requirements. However, the development of high-performance dynamic shape memory polymers (DSMPs) for DLP printing remains a significant challenge due to the inherent incompatibilities between the photopolymerization process and the curing/polymerization of high-strength polymers. Here, a mechanically robust DSMP compatible is developed with DLP printing, which incorporates dynamic covalent bonds of imine linking polyimide rigid segments, exhibiting remarkable mechanical performance (tensile strength ≈41.7 MPa, modulus ≈1.63 GPa) and thermal stability (Tg ∼ 113 °C, Td ∼ 208 °C). More importantly, benefiting from the solid-state plasticity conferred by dynamic covalent bonds, 4D printed structures demonstrate rapid network adaptiveness, enabling effortless realization of reconfiguration, self-healing, and recycling. Meanwhile, the extensive π-π conjugated structures bestow DSMP with an intrinsic photothermal effect, allowing controllable morphing of the 4D configuration through dual-mode triggering. This work not only greatly enriches the application scope of high-performance personalized configurations but also provides a reliable approach to addressing environmental pollution and energy crises.

Recent Advances in Whiskers: Properties and Clinical Applications in Dentistry

Whiskers are nanoscale, high-strength fibrous crystals with a wide range of potential applications in dentistry owing to their unique mechanical, thermal, electrical, and biological properties. They possess high strength, a high modulus of elasticity and good biocompatibility. Hence, adding these crystals to dental composites as reinforcement can considerably improve the mechanical properties and durability of restorations. Additionally, whiskers are involved in inducing the value-added differentiation of osteoblasts, odontogenic osteocytes, and pulp stem cells, and promoting the regeneration of alveolar bone, periodontal tissue, and pulp tissue. They can also enhance the mucosal barrier function, inhibit the proliferation of tumor cells, control inflammation, and aid in cancer prevention. This review comprehensively summarizes the classification, properties, growth mechanisms and preparation methods of whiskers and focuses on their application in dentistry. Due to their unique physicochemical properties, excellent biological properties, and nanoscale characteristics, whiskers show great potential for application in bone, periodontal, and pulp tissue regeneration. Additionally, they can be used to prevent and treat oral cancer and improve medical devices, thus making them a promising new material in dentistry.

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 Adapted to Vat Photopolymerization in 3D Printing: Characteristics and Medical Applications

Along with the rapid and extensive advancements in the 3D printing field, a diverse range of uses for 3D printing have appeared in the spectrum of medical applications. Vat photopolymerization (VPP) stands out as one of the most extensively researched methods of 3D printing, with its main advantages being a high printing speed and the ability to produce high-resolution structures. A major challenge in using VPP 3D-printed materials in medicine is the general incompatibility of standard VPP resin mixtures with the requirements of biocompatibility and biofunctionality. Instead of developing completely new materials, an alternate approach to solving this problem involves adapting existing biomaterials. These materials are incompatible with VPP 3D printing in their pure form but can be adapted to the VPP chemistry and general process through the use of innovative mixtures and the addition of specific pre- and post-printing steps. This review's primary objective is to highlight biofunctional and biocompatible materials that have been adapted to VPP. We present and compare the suitability of these adapted materials to different medical applications and propose other biomaterials that could be further adapted to the VPP 3D printing process in order to fulfill patient-specific medical requirements.