Tubular Scaffold with Shape Recovery Effect for Cell Guide Applications

A facile 3D bio-fabrication of customized tubular scaffolds using solvent-based extrusion printing for tissue-engineered tracheal grafts

Tracheal implantation remains a major therapeutic challenge due to the unavailability of donors and the lack of biomimetic tubular grafts. Fabrication of biomimetic tracheal scaffolds of suitable materials with matched rigidity, enhanced flexibility and biocompatibility has been a major challenge in the field of tracheal reconstruction. In this study, customized tubular grafts made up of FDA-approved polycaprolactone ( PCL ) and polyurethane ( PU ) were fabricated using a novel solvent-based extrusion 3D printing. The printed scaffolds were investigated by various physical, thermal, and mechanical characterizations such as contact angle measurement, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), radial compression, longitudinal compression, and cyclic radial compression. In this study, the native goat trachea was used as a reference for the fabrication of different types of scaffolds (cylindrical, bellow-shaped, and spiral-shaped). The mechanical properties of the goat trachea were also compared to find suitable formulations of PCL / PU . Spiral-shaped scaffolds were found to be an ideal shape based on longitudinal compression and torsion load maintaining clear patency. To check the long-term implantation, in vitro degradation test was performed for all the 3D printed scaffolds and it was found that blending of PU with PCL reduced the degradation behavior. The printed scaffolds were further evaluated for biocompatibility assay, live/dead assay, and cell adhesion assay using bone marrow-derived human mesenchymal stem cells (hMSCs). From biomechanical and biological assessments, PCL 70 / PU 30 of spiral-shaped scaffolds could be a suitable candidate for the development of tracheal regenerative applications.

Preparation of 3D printed calcium sulfate filled PLA scaffolds with improved mechanical and degradation properties

Scaffold is one of the key components for tissue engineering application. Three-dimensional (3D) printing has given a new avenue to the scaffolds design to closely mimic the real tissue. However, material selection has always been a challenge in adopting 3D printing for scaffolds fabrication, especially for hard tissue. The fused filament fabrication technique is one of the economical 3D printing technology available today, which can efficiently fabricate scaffolds with its key features. In the present study, a hybrid polymer-ceramic scaffold has been prepared by combining the benefit of synthetic biodegradable poly (lactic acid) (PLA) and osteoconductive calcium sulphate (CaS), to harness the advantage of both materials. Composite PLA filament with maximum ceramic loading of 40 wt% was investigated for its printability and subsequently scaffolds were 3D printed. The composite filament was extruded at a temperature of 160 °C at a constant speed with an average diameter of 1.66 ± 0.34 mm. PLA-CaS scaffold with ceramic content of 10%, 20%, and 40% was 3D printed with square pore geometry. The developed scaffolds were characterized for their thermal stability, mechanical, morphological, and geometrical accuracy. The mechanical strength was improved by 29% at 20 wt% of CaS. The porosity was found to be 50-60% with an average pore size of 550 µm with well-interconnected pores. The effect of CaS particles on the degradation behaviour of scaffolds was also assessed over an incubation period of 28 days. The CaS particles acted as porogen and improved the surface chemistry for future cellular activity, while accelerating the degradation rate.

Novel biohybrid spongy scaffolds for fabrication of suturable intraoral graft substitutes

Despite the fact that classic autograft is the gold standard material for periodontal plastic surgery, it has some drawbacks, including the need for a second surgical site and the scarcity of palatal donor tissue. However, only a few research works on the manufacturing of bioengineered intraoral connective tissue grafts have been conducted. In this work, porous bovine serum albumin methacryloyl/gelatin methacryloyl (BG) biohybrid scaffolds were developed for super-elasticity, shape recovery, suturability for persistent stability, sufficient scaffolding function, and convenient manipulating characteristics to fabricate an intraoral graft substitute with superb stability to resist frequent dynamic forces caused by functional movement (speaking, masticating, and swallowing). Furthermore, in a 3D cell culture assay, BG scaffolds demonstrated excellent cell adhesion and proliferation of L929 cells. In addition, the BG scaffolds were able to release Ibuprofen in a controlled manner for postoperative recovery. The use of a low-cost, optimized cryogelation technique for functional biomacromolecules offers up new possibilities to develop promising scaffolds for dental clinical settings.

Highlighting the medical applications of 3D printing in Egypt

Computer-assisted designing/computer-assisted manufacturing (CAD/CAM) technology has enabled medical practitioners to tailor physical models in a patient and purpose-specific fashion. It allows the designing and manufacturing of templates, appliances and devices with a high range of accuracy using biocompatible materials. The technique, nevertheless, relies on digital scanning (e.g., using intraoral scanners) and/or digital imaging (e.g., CT and MRI). In developing countries, there are some technical and financial limitations of implementing such advanced tools as an essential portion of medical applications. This paper focuses on the surgical and dental use of 3D printing technology in Egypt as a developing country.