Three-dimensional bio-printing and bone tissue engineering: technical innovations and potential applications in maxillofacial reconstructive surgery

Salah, Muhja,Tayebi, Lobat,Moharamzadeh, Keyvan,Naini, Farhad B. Korean Association of Maxillofacial Plastic and Re 2020 Maxillofacial Plastic Reconstructive Surgery Vol.42 No.-

Background: Bone grafting has been considered the gold standard for hard tissue reconstructive surgery and is widely used for large mandibular defect reconstruction. However, the midface encompasses delicate structures that are surrounded by a complex bone architecture, which makes bone grafting using traditional methods very challenging. Three-dimensional (3D) bioprinting is a developing technology that is derived from the evolution of additive manufacturing. It enables precise development of a scaffold from different available biomaterials that mimic the shape, size, and dimension of a defect without relying only on the surgeon's skills and capabilities, and subsequently, may enhance surgical outcomes and, in turn, patient satisfaction and quality of life. Review: This review summarizes different biomaterial classes that can be used in 3D bioprinters as bioinks to fabricate bone scaffolds, including polymers, bioceramics, and composites. It also describes the advantages and limitations of the three currently used 3D bioprinting technologies: inkjet bioprinting, micro-extrusion, and laserassisted bioprinting. Conclusions: Although 3D bioprinting technology is still in its infancy and requires further development and optimization both in biomaterials and techniques, it offers great promise and potential for facial reconstruction with improved outcome.

DEVELOPMENT AND CHARACTERIZATION OF SiC-Al2O3-Al CERAMIC MATRIX NANOCOMPOSITE POWDER

MARYAM KARBASI,MEHDI RAZAVI,MINA AZADI,LOBAT TAYEBI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.6

In this study, SiC–Al2O3–Al ceramic matrix nanocomposite powder was successfully synthesized employing mechanical alloying technique, through mechanochemical reaction among Silicon dioxide (SiO2), Carbon (C) and Aluminum (Al). For the commercial purposes, the materials (SiO2, C and Al powders) and also the method of synthesis (mechanical alloying) is considered to be cost effective for the production of SiC–Al2O3–Al nanocomposite. Addition of alumina (Al2O3) and aluminum to silicon carbide (SiC) in a nancomposite form can improve the fracture toughness, strength and fatigue crack resistance of SiC and make it a leading material for many commercial applications specially by considering the cost-effective method of production. The structural evaluation of powder particles after different milling times was conducted by X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The results showed that during ball milling the SiO2, C and Al reacted with a combustion mode producing SiC–Al2O3–Al nanocomposite after 24 h ball milling and annealing at the temperature of 920°C. The crystallite sizes of phases remained in nanometric scale after annealing at 920°C for 1 h. Based on our investigation, it was revealed that ball milling and annealing process decreases the temperature of reaction between SiO2 and C from 1500°C to 920°C.

Nanostructured Hydroxyapatite for Biomedical Applications: From Powder to Bioceramic

Eslami, Hossein,Tahriri, Mohammadreza,Moztarzadeh, Fathollah,Bader, Rizwan,Tayebi, Lobat The Korean Ceramic Society 2018 한국세라믹학회지 Vol.55 No.6

In this study, a wet chemical method was used to synthesize nanostructured hydroxyapatite for biomedical applications. Diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials with a sodium hydroxide solution as an agent for pH adjustment. Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, differential thermal analysis, thermal gravimetric analysis, atomic absorption spectroscopy, and ethylenediaminetetraacetic acid (EDTA) titration analysis were used to characterize the synthesized powders. Having been uniaxially pressed, the powders formed a disk-like shape. The sinterability and electrical properties of the samples were examined, and the three-point bending test allowed for the measurement of their mechanical properties. Sedimentation analysis was used to analyze the slurry ability of hydroxyapatite. As in-vitro biological properties of the samples, biocompatibility and cytotoxicity were assessed using osteoblast-like cells and the L929 cell line, respectively. Solubility was assessed by employing a simulated body fluid.

Assessment of pH Responsive Delivery of Methotrexate Based on PHEMA-st-PEG-DA Nanohydrogels

Javad Farzanfar,Fatemeh Farjadian,Amir Roointan,Soliman Mohammadi-Samani,Lobat Tayebi 한국고분자학회 2021 Macromolecular Research Vol.29 No.1

Nanohydrogels (NHs) are novel and attractive carriers for various anticancer factors delivery. The objective of present study is development of a safe NH for pH responsive delivery of methotrexate (MTX). Herein, poly (hydroxyethyl methacrylate) is utilized as the main structure, which is cross-linked with poly(ethyleneglycol) diacrylate (PEG-DA) through reversible addition fragmentation chain transfer polymerization technique. After synthesis, the developed structure is characterized using different methods, including 1H NMR, FT-IR, size exclusion chromatography, transmission electron microscopy and dynamic light scattering. The results confirm successful synthesis of the NH with acceptable yield and nano scale mean size of 194 nm. Methotrexate is conjugated with the aforementioned structure through pH responsive esteric bond. The efficiency of the prepared NH in loading and release of the anticancer drug, methotrexate, is tested. The developed NH shows great potential in methotrexate loading, as well as a faster release rate of methotrexate in acidic pH. The results of in vitro toxicity assessment on MCF-7 as a breast cancer cell line reveal an improved cytotoxicity induction by the methotrexate loaded particles when compared with the free MTX molecules. The suitable size (<200 nm), great potential in loading and release of the methotrexate and cytotoxicity induction in cancer cells are the reliable features of NH as an ideal anti-cancer vehicle.

A new phantom to evaluate the tissue dissolution ability of endodontic irrigants and activating devices

Khoshroo Kimia,Shah Brinda,Johnson Alexander,Baeten John,Barry Katherine,Tahriri Mohammadreza,Ibrahim Mohamed S.,Tayebi Lobat 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.4

Objective: The aim of this study was to introduce a gelatin/bovine serum albumin (BSA) tissue standard, which provides dissolution properties identical to those of biological tissues. Further, the study evaluated whether the utilization of endodontic activating devices led to enhanced phantom dissolution rates. Materials: and Methods Bovine pulp tissue was obtained to determine a benchmark of tissue dissolution. The surface area and mass of samples were held constant while the ratio of gelatin and BSA were varied, ranging from 7.5% to 10% gelatin and 5% BSA. Each sample was placed in an individual test tube that was filled with an appropriate sodium hypochlorite solution for 1, 3, and 5 minutes, and then removed from the solution, blotted dry, and weighed again. The remaining tissue was calculated as the percent of initial tissue to determine the tissue dissolution rate. A radiopaque agent (sodium diatrizoate) and a fluorescent dye (methylene blue) were added to the phantom to allow easy quantification of phantom dissolution in a canal block model when activated using ultrasonic (EndoUltra) or sonic (EndoActivator) energy. Results: The 9% gelatin + 5% BSA phantom showed statistically equivalent dissolution to bovine pulp tissue at all time intervals. Furthermore, the EndoUltra yielded significantly more phantom dissolution in the canal block than the EndoActivator or syringe irrigation. Conclusions: Our phantom is comparable to biological tissue in terms of tissue dissolution and could be utilized for in vitro tests due to its injectability and detectability.

Advancements in craniofacial prosthesis fabrication: A narrative review of holistic treatment

Jazayeri, Hossein E.,Kang, Steve,Masri, Radi M.,Kuhn, Lauren,Fahimipour, Farahnaz,Vanevenhoven, Rabecca,Thompson, Geoffrey,Gheisarifar, Maryam,Tahriri, Mohammadreza,Tayebi, Lobat The Korean Academy of Prosthodonitics 2018 The Journal of Advanced Prosthodontics Vol.10 No.6

The treatment of craniofacial anomalies has been challenging as a result of technological shortcomings that could not provide a consistent protocol to perfectly restore patient-specific anatomy. In the past, wax-up and impression-based maneuvers were implemented to achieve this clinical end. However, with the advent of computer-aided design and computer-aided manufacturing (CAD/CAM) technology, a rapid and cost-effective workflow in prosthetic rehabilitation has taken the place of the outdated procedures. Because the use of implants is so profound in different facets of restorative dentistry, their placement for craniofacial prosthesis retention has also been widely popular and advantageous in a variety of clinical settings. This review aims to effectively describe the well-rounded and interdisciplinary practice of craniofacial prosthesis fabrication and retention by outlining fabrication, osseointegrated implant placement for prosthesis retention, a myriad of clinical examples in the craniofacial complex, and a glimpse of the future of bioengineering principles to restore bioactivity and physiology to the previously defected tissue.