The Efficacy of Commercial Tooth Storage Media for Maintaining the Viability of Human Periodontal Ligament Fibroblasts

Aim To evaluate Save‐A‐Tooth (SAT), EMT Toothsaver (EMT) and Hank\u27s Balanced Salt Solution (HBSS) for their influence on the viability and proliferative capacity of human periodontal ligament fibroblasts (HPDLFs). Methodology Primary HPDLFs were seeded into 96‐well cell culture plates and exposed to SAT, EMT, HBSS and water (negative control) for 0.5, 1, 3, 6, 12 and 24 h at room temperature (22 °C). After each exposure time, cell viability was measured through quantifying adenosine triphosphate (ATP) using a luminescent dye. The proliferative capacity was also quantified using the PrestoBlue assay after 12 or 24 h storage in each medium. The data were analysed statistically by two‐way anova and post hoc Least Significant Difference (LSD) test (P \u3c 0.05). The morphology of the cells after 12 h storage was also investigated through live/dead viability/cytotoxicity kit together with fluorescence microscopy. Results There was no significant difference in cell viability amongst HBSS, SAT and EMT groups up to 6 h. SAT was effective in maintaining cell viability only up to 12 h and then became detrimental to HPDLF; after 24 h, the effectiveness of SAT in maintaining cell viability was similar to that of water (P \u3e 0.05). Amongst all the media, only EMT could maintain the proliferative capacity of HPDLFs significantly higher than the negative control, that is water (P \u3c 0.05) after 24 h storage. Conclusion EMT maintained the proliferative capacity of HPDLFs after 24 h storage

On-Chip Detection of Gel Transition Temperature using a Novel Micro-Thermomechanical Method

We present a new thermomechanical method and a platform to measure the phase transition temperature at microscale. A thin film metal sensor on a membrane simultaneously measures both temperature and mechanical strain of the sample during heating and cooling cycles. This thermomechanical principle of operation is described in detail. Physical hydrogel samples are prepared as a disc-shaped gels (200 μm thick and 1 mm diameter) and placed between an on-chip heater and sensor devices. The sol-gel transition temperature of gelatin solution at various concentrations, used as a model physical hydrogel, shows less than 3% deviation from in-depth rheological results. The developed thermomechanical methodology is promising for precise characterization of phase transition temperature of thermogels at microscale

3D Printed TCP-Based Scaffold Incorporating VEGF-Loaded PLGA Microspheres for Craniofacial Tissue Engineering

Objective 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 engineeringmethods 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. Methods The paste, composed of (VEGF-loaded PLGA)-containing gelatin/alginate/β-TCP in water, was loaded into standard Nordson cartridges and promptly employed for printing the scaffolds. Rheological characterization of various gelatin/alginate/β-TCP formulations led to an optimized paste as a printable bioink at room temperature. Results 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. Significance 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

A Current Overview of Materials and Strategies for Potential Use in Maxillofacial Tissue Regeneration

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 printed tissue engineered model for bone invasion of oral cancer

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

Antibacterial and Osteoinductive Implant Surface Using Layer-by-Layer Assembly

Osseointegration of dental, craniofacial, and orthopedic implants is critical for their long-term success. Multifunctional surface treatment of implants was found to significantly improve cell adhesion and induce osteogenic differentiation of dental-derived stem cells in vitro. Moreover, local and sustained release of antibiotics via nanolayers from the surface of implants can present unparalleled therapeutic benefits in implant dentistry. Here, we present a layer-by-layer surface treatment of titanium implants capable of incorporating BMP-2-mimicking short peptides and gentamicin to improve their osseointegration and antibacterial features. Additionally, instead of conventional surface treatments, we employed polydopamine coating before layer-by-layer assembly to initiate the formation of the nanolayers on rough titanium surfaces. Cytocompatibility analysis demonstrated that modifying the titanium implant surface with layer-by-layer assembly did not have adverse effects on cellular viability. The implemented nanoscale coating provided sustained release of osteoinductive peptides with an antibacterial drug. The surface-functionalized implants showed successful osteogenic differentiation of periodontal ligament stem cells and antimicrobial activity in vitro and increased osseointegration in a rodent animal model 4 wk postsurgery as compared with untreated implants. Altogether, our in vitro and in vivo studies suggest that this approach can be extended to other dental and orthopedic implants since this surface functionalization showed improved osseointegration and an enhanced success rate

Critical-sized bone defects regeneration using a bone-inspired 3D bilayer collagen membrane in combination with leukocyte and platelet-rich fibrin membrane (L-PRF): An in vivo study

Objectives: We aim to develop a 3D-bilayer collagen (COL) membrane reinforced with nano beta-tricalcium-phosphate (nβ-TCP) particles and to evaluate its bone regeneration in combination with leukocyte-platelet-rich fibrin (L-PRF) in vivo. Background data: L-PRF has exhibited promising results as a cell carrier in bone regeneration in a number of clinical studies, however there are some studies that did not confirm the positive results of L-PRF application. Methods: Mechanical & physiochemical characteristics of the COL/nβ-TCP membrane (1/2 & 1/4) were tested. Proliferation and osteogenic differentiation of seeded cells on bilayer collagen/nβ-TCP thick membrane was examined. Then, critical-sized calvarial defects in 8 white New Zealand rabbits were filled with either Col, Col/nβ-TCP, Col/nβ-TCP combined with L-PRF membrane, or left empty. New bone formation (NBF) was measured histomorphometrically 4 & 8 weeks postoperatively. Results: Compressive modulus increases while porosity decreases with higher β-TCP concentrations. Mechanical properties improve, with 89 porosity (pore size �100 μm) in the bilayer-collagen/nβ-TCP membrane. The bilayer design also enhances the proliferation and ALP activity. In vivo study shows no significant difference among test groups at 4 weeks, but Col/nβ-TCP + L-PRF demonstrates more NBF compared to others (P < 0.05) after 8 weeks. Conclusion: The bilayer-collagen/nβ-TCP thick membrane shows promising physiochemical in vitro results and significant NBF, as ¾ of the defect is filled with lamellar bone when combined with L-PRF membrane. © 201

Gelation temperatures of 10%, 15%, and 20% gelatin, measured by rheology and micro-thermomechanical sensors for comparison.

<p>Gelation temperatures of 10%, 15%, and 20% gelatin, measured by rheology and micro-thermomechanical sensors for comparison.</p

Gelation temperatures of 10%, 15%, and 20% gelatin measured by the micro-thermomechanical method using sensor #1 (dashed line), sensor #2 (dotted line), and standard rheology (solid line).

<p>Gelation temperatures of 10%, 15%, and 20% gelatin measured by the micro-thermomechanical method using sensor #1 (dashed line), sensor #2 (dotted line), and standard rheology (solid line).</p

Phase transition measurement of purified wax.

<p>(a) Micro-thermomechanical measurement by sensor #1. The transition temperature is detected during either the heating or the cooling cycle. The deviation point is circled. The deviation is caused by the stress applied by the sample during the phase transition. (b) Standard DSC method for the phase transition measurement. The linear approximation is used to determine the phase transition temperature.</p