Treatment of Critical-Sized Calvarial Defects in Rats with Preimplanted Transplants

Advances in reparative materials for infectious bone defects and their applications in maxillofacial regions

Infectious bone defects are characterized by the partial loss or destruction of bone tissue resulting from bacterial contaminations subsequent to diseases or external injuries. Traditional bone transplantation and clinical methods are insufficient in meeting the treatment demands for such diseases. As a result, researchers have increasingly focused on the development of more sophisticated biomaterials for improved therapeutic outcomes in recent years. This review endeavors to investigate specific reparative materials utilized for the treatment of infectious bone defects, particularly those present in the maxillofacial region, with a focus on biomaterials capable of releasing therapeutic substances, functional contact biomaterials, and novel physical therapy materials. These biomaterials operate via heightened antibacterial or osteogenic properties in order to eliminate bacteria and/or stimulate bone cells regeneration in the defect, ultimately fostering the reconstitution of maxillofacial bone tissue. Based upon some successful applications of new concept materials in bone repair of other parts, we also explore their future prospects and potential uses in maxillofacial bone repair later in this review. We highlight that the exploration of advanced biomaterials holds promise in establishing a solid foundation for the development of more biocompatible, effective, and personalized treatments for reconstructing infectious maxillofacial defects.

Synergistically Promoting Bone Regeneration by Icariin-Incorporated Porous Microcarriers and Decellularized Extracellular Matrix Derived From Bone Marrow Mesenchymal Stem Cells

Multifunctionality has becoming essential for bone tissue engineering materials, such as drug release. In this study, icariin (ICA)-incorporated poly(glycolide-co-caprolactone) (PGCL) porous microcarriers were fabricated and then coated with decellularized extracellular matrix (dECM) which was derived from bone marrow mesenchymal stem cells (BMSC). The porous structure was generated due to the soluble gelatin within the microcarriers. The initial released ICA in microcarriers regulated osteogenic ECM production by BMSCs during ECM formation. The dECM could further synergistically enhance the migration and osteogenic differentiation of BMSCs together with ICA as indicated by the transwell migration assay, ALP and ARS staining, as well as gene and protein expression. Furthermore, in vivo results also showed that dECM and ICA exhibited excellent synergistic effects in repairing rat calvarial defects. These findings suggest that the porous microcarriers loaded with ICA and dECM coatings have great potential in the field of bone tissue engineering.

Monetite, an important calcium phosphate compound-Its synthesis, properties and applications in orthopedics

This review recognizes a unique calcium phosphate (CaP) phase known as monetite or dicalcium phosphate anhydrous (DCPA, CaHPO₄), and presents an overview of its properties, processing, and applications in orthopedics. The motivation for the present effort is to highlight the state-of-the-art research and development of monetite and propel the research community to explore more of its potentials in orthopedics. After a brief introduction of monetite, we provide a summary of its various synthesis routes like dehydration, solvent-based, energy-assisted processes and also discuss the formation of different crystal structures with respect to the synthesis conditions. Subsequently, we discuss the material's noteworthy physico-chemical properties including the crystal structure, vibrational spectra, solubility, thermal decomposition, and conversion to other phases. Of note, we focus on the biological (in vitro and in vivo) properties of monetite, given its ever-increasing popularity as a biomaterial for medical implants. Appropriately, we discuss various orthopedic applications of monetite as bone cement, implant coatings, granules for defect fillers, and scaffolds. Many in vitro and in vivo studies confirmed the favorable osteointegration and osteoconduction properties of monetite products, along with a better balance between implant resorption and new bone formation as compared to other CaP phases. The review ends with translational aspects of monetite and presents thoughts about its possible future research directions. Further research may explore but not limited to improvements in mechanical strength of monetite-based scaffolds, using monetite particles as a therapeutic agent delivery, and tissue engineering strategies where monetite serves as the biomaterial. STATEMENT OF SIGNIFICANCE: This is the first review that focusses on the favorable potential of monetite for hard tissue repair and regeneration. The article accurately covers the "Synthesis-Structure-Property-Applications" correlations elaborating on monetite's diverse material properties. Special focus is put on the in vitro and in vivo properties of the material highlighting monetite as an orthopedic material-of-choice. The synthesis techniques are discussed which provide important information about the different fabrication routes for monetite. Most importantly, the review provides comprehensive knowledge about the diverse biomedical applications of monetite as granules, defect--specific scaffolds, bone cements and implant coatings. This review will help to highlight monetite's potential as an effective regenerative medicine and catalyze the continuing translation of this bioceramic from the laboratory to clinics.

Additive manufacturing pertaining to bone: Hopes, reality and future challenges for clinical applications

For the past 20 years, the democratization of additive manufacturing (AM) technologies has made many of us dream of: low cost, waste-free, and on-demand production of functional parts; fully customized tools; designs limited by imagination only, etc. As every patient is unique, the potential of AM for the medical field is thought to be considerable: AM would allow the division of dedicated patient-specific healthcare solutions entirely adapted to the patients' clinical needs. Pertinently, this review offers an extensive overview of bone-related clinical applications of AM and ongoing research trends, from 3D anatomical models for patient and student education to ephemeral structures supporting and promoting bone regeneration. Today, AM has undoubtably improved patient care and should facilitate many more improvements in the near future. However, despite extensive research, AM-based strategies for bone regeneration remain the only bone-related field without compelling clinical proof of concept to date. This may be due to a lack of understanding of the biological mechanisms guiding and promoting bone formation and due to the traditional top-down strategies devised to solve clinical issues. Indeed, the integrated holistic approach recommended for the design of regenerative systems (i.e., fixation systems and scaffolds) has remained at the conceptual state. Challenged by these issues, a slower but incremental research dynamic has occurred for the last few years, and recent progress suggests notable improvement in the years to come, with in view the development of safe, robust and standardized patient-specific clinical solutions for the regeneration of large bone defects.