<p>A Novel 3D-bioprinted Porous Nano Attapulgite Scaffolds with Good Performance for Bone Regeneration</p>

Abstract

Background: Natural clay nanomaterials are an emerging class of biomaterial with great potential for tissue engineering and regenerative medicine applications, most notably for osteogenesis. Materials and Methods: Herein, for the first time, novel tissue engineering scaffolds were prepared by 3D bioprinter using nontoxic and bioactive natural attapulgite (ATP) nanorods as starting materials, with polyvinyl alcohol as binder, and then sintered to obtain final scaffolds. The microscopic morphology and structure of ATP particles and scaffolds were observed by transmission electron microscope and scanning electron microscope. In vitro biocompatibility and osteogenesis with osteogenic precursor cell (hBMSCs) were assayed using MTT method, Live/Dead cell staining, alizarin red staining and RT-PCR. In vivo bone regeneration was evaluated with micro-CT and histology analysis in rat cranium defect model. Results: We successfully printed a novel porous nano-ATP scaffold designed with inner channels with a dimension of 500 µm and wall structures with a thickness of 330 µm. The porosity of current 3D-printed scaffolds ranges from 75% to 82% and the longitudinal compressive strength was up to 4.32±0.52 MPa. We found firstly that nano-ATP scaffolds with excellent biocompatibility for hBMSCscould upregulate the expression of osteogenesisrelated genes bmp2 and runx2 and calcium deposits in vitro. Interestingly, micro-CT and histology analysis revealed abundant newly formed bone was observed along the defect margin, even above and within the 3D bioprinted porous ATP scaffolds in a rat cranial defect model. Furthermore, histology analysis demonstrated that bone was formed directly following a process similar to membranous ossification without any intermediate cartilage formation and that many newly formed blood vessels are within the pores of 3D-printed scaffolds at four and eight weeks. Conclusion: These results suggest that the 3D-printed porous nano-ATP scaffolds are promising candidates for bone tissue engineering by osteogenesis and angiogenesis.

Chitin Nerve Conduits with Three-Dimensional Spheroids of Mesenchymal Stem Cells from SD Rats Promote Peripheral Nerve Regeneration

“…The biocompatibility of the chitin surface was investigated by live/dead cell staining [26]. Briefly, Schwann cells (SCs, isolated from the sciatic nerves of rats) were seeded on As described previously, a scanning electron microscope (JEOL, Tokyo, Japan) was used to observe the surface morphology of the chitin conduits [22].…”

“…The biocompatibility of the chitin surface was investigated by live/dead cell staining [26]. Briefly, Schwann cells (SCs, isolated from the sciatic nerves of rats) were seeded on the chitin film surface at a density of 1.0 × 10 5 cells/cm 2 .…”

Biopolímeros: Aplicaciones de andamios en medicina regenerativa

“…Para lograr la administración controlada de señales bioquímicas o físicas mediante la utilización de un biomaterial se deben considerar la actividad y estabilidad biológica de las sustancias bioactivas, la cantidad de carga del andamio, la distribución de las biomoléculas en el andamio y la afinidad cinética de liberación de las moléculas, estos sistemas pueden ser implementados al momento de la creación del andamio o añadirlos por separado al momento de generar la matriz; lo que se busca es orientar la función celular para la liberación de moléculas específicas que permitan la adhesión y proliferación celular hacia la formación de un tejido en específico (Wang, et al, 2020).…”

“…La aplicación del uso de las nanoarcillas como un nuevo tipo de andamio se ha convertido en un área capaz de aumentar la regeneración celular y la formación de tejidos. Wang, et al (2020) produce Figura 3. Métodos empleados para la liberación guiada de fármacos.…”

LINC02288 promotes chondrocyte apoptosis and inflammation through miR‐374a‐3p targeting RTN3

“…10 However, these measures have no effects on preventing the degeneration of articular cartilage. 8 Therefore, further exploration of the pathogenesis of OA may help identify effective therapies to prevent OA and reduce its severity.…”