how often does the letter "n" occur in:
feb 11, 2019 | by cameron
bioplotting hybrid scaffolds – 3d printing smart structures. image credit: envisiontec
dr. qing li and a team of scientists recently completed a study investigating the compatibility of hydroxyapatite and collagen when used for 3d bioprinted scaffolds that serve as bone substitutes. 3d printing is the future of repairing bone trauma and defects because it can manipulate the biocompatible materials and live tissues into the organic geometries necessary to stimulate cellular bone growth; bone is porous and 3d printing can replicate that porosity. li and the team of researchers worked with two types of hydroxyapatite (ha), a mineral that makes up most of the inorganic matter in tooth enamel and bones.
function of the 3d-bioplotter system as demonstrated at rapid 2015. credit: mary ann liebert, inc.
nano hydroxyapatite (nha) and deproteinized bovine bone (dbb) were each mixed with collagen (col) to create two bio-inks for 3d printing with an envisiontec 3d-bioplotter, an advanced 3d bioprinter from germany capable of low- and high-temperature bioprinting. they 3d printed a porous architecture that simulated cancellous bone (the spongy type of bone) with each formula and then ran them through a battery of materials characterization analyses, including x-ray photoelectron spectroscopy (xps), x-ray powder diffraction (xrd), and fourier transform infrared spectroscopy (ftir). the use of scanning electron microscopy (sem) revealed “different surface morphologies of the ha crystals as well as the scaffolds, which would be the main factors affecting the internal porous structure of the scaffold.” matching bone’s porosity is incredibly important because that porous nature enables flexibility and strength while also allowing nutrients to be dispersed throughout bones.
the 3d-bioplotter system: a versatile rapid prototyping tool to process biomaterials for computer-aided tissue engineering based on 3d computer-aided design (cad) of patient computer tomography (ct) data to form a physical 3d scaffold with a designed outer form and open inner structure. image credit: envisiontec
the young’s modulus (a measure of stiffness) was highest on the nha/col group at 7.9 ± 0.3 mpa, compared to 4.5 ± 0.7 mpa for the dbb/col group and 3.5 ± 0.4 mpa for col alone. immunofluorescence staining showed that both composite scaffolds equally supported cell proliferation. additionally, real-time polymerase chain reaction (rt-pcr) indicated proper expression levels of the osteogenesis-related genes. “the researchers demonstrated osteogenesis and increased effects of extracellular matrix formation for hbmscs (human bone marrow stromal cells) cultured on the bioplotted 3d scaffolds to confirm surface biocompatibility.”
human mesenchymal stem cell characterization with antibody markers directed to regions of interest. li et al. used dapi (blue, nuclei) fitc-phalloidin (red, f-actin or cytoskeleton) and vinculin (green, membrane-cytoskeleton protein). image credit: euro stem cell
to summarize, their results prove that ."there is much ongoing research in regards to 3d printing bone and connective tissues, so this new data will go a long way towards advancing the field.
posted in 3d printing applications
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In the text, there are 182 "n"s.
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