Porous scaffolds were 3D-printed using poly lactic-co-glycolic acid (PLGA)/TiO 2 composite (10:1 weight ratio) for bone tissue engineering applications. Addition of TiO 2 nanoparticles improved the compressive modulus of scaffolds. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed an increase in both glass transition temperature and thermal decomposition onset of the composite compared to pure PLGA. Furthermore, addition of TiO 2 was found to enhance the wettability of the surface evidenced by reducing the contact angle from 90.5 ± 3.2 to 79.8 ± 2.4 which in favor of cellular attachment and activity. The obtained results revealed that PLGA/TiO 2 scaffolds significantly improved osteoblast proliferation compared to pure PLGA (P < 0.05). Furthermore, osteoblasts cultured on PLGA/TiO 2 nanocomposite represented significantly higher ALP activity and improved calcium secretion compared to pure PLGA scaffolds (p < 0.05).

Vascularization is a critical process during bone regeneration/repair and the lack of tissue vascularization is recognized as a major challenge in applying bone tissue engineering methods for cranial and maxillofacial surgeries. The aim of our study is to fabricate a vascular endothelial growth factor (VEGF)-loaded gelatin/alginate/β-TCP composite scaffold by 3D printing method using a computer-assisted design (CAD) model. Rheological characterization of various gelatin/alginate/β-TCP formulations led to an optimized paste as a printable bioink at room temperature. VEGF-loaded PLGA microspheres were then incorporated into the paste prior to printing to ensure sustained release of the growth factor. The in vitro release kinetics of the loaded VEGF revealed that the designed scaffolds fulfill the bioavailability of VEGF required for vascularization in the early stages of tissue regeneration. The results were confirmed by two times increment of proliferation of human umbilical vein endothelial cells (HUVECs) seeded on the scaffolds after 10 days. The compressive modulus of the scaffolds, 98 ± 11 MPa, was found to be in the range of cancellous bone suggesting their potential application for craniofacial tissue engineering. Osteoblast culture on the scaffolds showed that the construct supports cell viability, adhesion and proliferation. It was found that the ALP activity increased over 50% using VEGF-loaded scaffolds after 2 weeks of culture. In conclusion, the 3D printed gelatin/alginate/β-TCP scaffold with slow releasing of VEGF can be considered as a potential candidate for regeneration of craniofacial defects.

The objective of this study was to evaluate the effect of the addition of synthesized hydroxyapatite (HA) and fluorapatite (FA) nanoparticles to a glass-ionomer cement (GIC) on the mechanical properties, while preserving their unique and potent clinical properties.Bioceramics, such as HA and FA, have been recognized as restorative materials (e.g. GICs) in dentistry due to their chemical and biological compatibility with human hard tissues, which are considered calcium phosphate complexes. In this study, both of these inorganic nanoparticles (HA and FA) were synthesized via a wet-chemical precipitation method. The obtained nanoparticles were characterized with X-ray diffraction (XRD), inductively coupled plasma

Tissue regeneration is rapidly evolving to treat anomalies in the entire human body. The production of biodegradable, customizable scaffolds to achieve this clinical aim is dependent on the interdisciplinary collaboration among clinicians, bioengineers and materials scientists. While bone grafts and varying reconstructive procedures have been traditionally used for maxillofacial defects, the goal of this review is to provide insight on all materials involved in the progressing utilization of the tissue engineering approach to yield successful treatment outcomes for both hard and soft tissues. In vitro and in vivo studies that have demonstrated the restoration of bone and cartilage tissue with different scaffold material types, stem cells and growth factors show promise in regenerative treatment interventions for maxillofacial defects. The repair of the temporomandibular joint (TMJ) disc and mandibular bone were discussed extensively in the report, supported by evidence of regeneration of the same tissue types in different medical capacities. Furthermore, in addition to the thorough explanation of polymeric, ceramic, and composite scaffolds, this review includes the application of biodegradable metallic scaffolds for regeneration of hard tissue. The purpose of compiling all the relevant information in this review is to lay the foundation for future investigation in materials used in scaffold synthesis in the realm of oral and maxillofacial surgery.

3D dual porosity protein-based scaffolds have been developed using the combination of foaming and freeze-drying. The suggested approach leads to the production of large, highly porous scaffolds with negligible shrinkage and deformation compared to the conventional freeze-drying method. Scanning electron microscopy, standard histological processing and mercury intrusion porosimetry confirmed the formation of a dual network in the form of big primary pores (243 ± 14 µm) embracing smaller secondary pores (42 ± 3 µm) opened onto their surface, resembling a vascular network. High interconnectivity of the pores, confirmed by micro-CT, is shown to improve diffusion kinetics and support a relatively uniform distribution of isolated human dental pulp stem cells within the scaffold compared to conventional scaffolds. Dual network scaffolds indicate more than three times as high cell proliferation capability as conventional scaffolds in 14 days.

In this research, the three dimensional porous scaffolds made of a polycaprolactone (PCL) microsphere/TiO nanotube (TNT) composite was fabricated and evaluated for potential bone substitute applications. We used a microsphere sintering method to produce three dimensional PCL microsphere/TNT composite scaffolds. The mechanical properties of composite scaffolds were regulated by varying parameters, such as sintering time, microsphere diameter range size and PCL/TNT ratio. The obtained results ascertained that the PCL/TNT (0.5wt%) scaffold sintered at 60°C for 90min had the most optimal mechanical properties and an appropriate pore structure for bone tissue engineering applications. The average pore size and total porosity percentage increased after increasing the microsphere diameter range for PCL and PCL/TNT (0.5wt%) scaffolds. The degradation rate was relatively high in PCL/TNT (0.5wt%) composites compared to pure PCL when the samples were placed in the simulated body fluid (SBF) for 6weeks. Also, the compressive strength and modulus of PCL and PCL/TNT (0.5wt%) composite scaffolds decreased during the 6weeks of storage in SBF. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and alkaline phosphates (ALP) activity results demonstrated that a generally increasing trend in cell viability was observed for PCL/TNT (0.5wt%) scaffold sintered at 60°C for 90min compared to the control group. Eventually, the quantitative RT-PCR data provided the evidence that the PCL scaffold containing TiO nanotube constitutes a good substrate for cell differentiation leading to ECM mineralization.

Recent advances in three-dimensional printing technology have led to a rapid expansion of its applications in tissue engineering. The present study was designed to develop and characterize an in vitro multi-layered human alveolar bone, based on a 3D printed scaffold, combined with tissue engineered oral mucosal model. The objective was to incorporate oral squamous cell carcinoma (OSCC) cell line spheroids to the 3D model at different anatomical levels to represent different stages of oral cancer. Histological evaluation of the 3D tissue model revealed a tri-layered structure consisting of distinct epithelial, connective tissue, and bone layers; replicating normal oral tissue architecture. The mucosal part showed a well-differentiated stratified oral squamous epithelium similar to that of the native tissue counterpart, as demonstrated by immunohistochemistry for cytokeratin 13 and 14. Histological assessment of the cancerous models demonstrated OSCC spheroids at three depths including supra-epithelial level, sub-epithelial level, and deep in the connective tissue-bone interface. The 3D tissue engineered composite model closely simulated the native oral hard and soft tissues and has the potential to be used as a valuable in vitro model for the investigation of bone invasion of oral cancer and for the evaluation of novel diagnostic or therapeutic approaches to manage OSCC in the future.

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