Nano-engineered hydrogels for 3D bioprinted bone scaffolds
ESTIMATIVE RESULTS
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Lab technology and protocols of obtaining different nanostructured hydrogels;
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Scientific data concerning the physico-chemical and biological properties of the newly obtained formulations;
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Experimental protocols for 3D printing of nanostructured formulations intended for bone tissue regeneration;
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Experimental data sets generated by a comprehensive characterization of the effect of fabrication parameters and ink-related parameters on the printability;
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In vitro testing protocols for the optimized 3D printing ink formulations;
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Working protocols to prepare cell-embedded nanocomposites;
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Complex 3D fabricated models designed for bone tissue regeneration;
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Protocols for obtaining the optimized version of 3D printed materials for implantation in animal models;
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At least four papers submitted for evaluation in ISI journal;
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At least two scientific communications at relevant international conferences.
PROJECT RESULTS
Stage 1 - 14/09/2020 - 31/12/2020 - 73.005 lei
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The development of porous structures based on nanostructured hydrogels
In this stage, several nanocomposite hydrogel systems based on
methacrylated bovine gelatin, apple pectin reinforced with
nanocellulose and octa-methacrylated/1-methacrylate polyhedral
oligomeric silsesquioxanes were synthesized and evaluated in
order to select formulations with optimal properties. To obtain
nanocomposite hydrogels and to investigate the effect of
cross-linking strategies on the properties of the samples
(including the systems homogeneity versus POSS’s dispersion),
various experimental protocols were employed where the influence
of reaction conditions such as UV radiation exposure time,
cross-linking with calcium chloride solution (time, concentration),
GelMA/PeMA ratio, concentration and type of POSS, ultrasonication
time and the presence of dimethyl sulfoxide (DMSO) in the system were considered for investigation.
The synthesized hydrogels were characterized using advanced techniques to emphasize their physico-chemical,
mechanical, thermal and structural properties.​
Scientific and technical report in extenso - stage I / 2020
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Stage 2 - 01/01/2021 - 31/12/2021- 212.782 lei
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The design and manufacturing of acellular constructs by 3D printing using the obtained nanostructured formulations
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During this stage, the in vitro biocompatibility of the nanocomposite
hydrogel systems synthesized in the previous stage was confirmed.
After complex rheological studies of the proposed formulations and
the tailoring of the optimal composition of the ink, various
experimental protocols were approached for the 3D printing of
acellular polymeric scaffolds using nano-formulations based on
bovine gelatin functionalized with methacrylate groups, modified
apple pectin with a low degree of methoxylation, nanocellulose and
polyhedral oligomeric silsesquioxanes. For a more in-depth study of
the effects of POSS degree of functionalization within the polymeric
matrix, reinforced materials with a new type of non-functionalized
POSS, POSS0, were also synthesized. To obtain a homogeneous
distribution of the nanostructured organic-inorganic compound
throughout the hydrophilic network, each type of POSS was firstly
dispersed in a solvent (chloroform) and this suspension was added
to the nanocellulose gel. After obtaining the tissue constructs, they were lyophilized and characterized in terms of in vitro mineralization potential, enzyme degradation kinetics and internal architecture. In addition, the effect of using a dual crosslinking strategy consisting of photo-crosslinking and enzymatic crosslinking with transglutaminase was studied by a comparative characterization of the swelling kinetics and the composition of nanocomposite hydrogels obtained with each.
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Some of the scientific results obtained in stage 2 of the current project were published in the form of a summary, on the website: http://tehnostiri.ro/index.php/2021/06/15/8344/.
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Scientific and technical report in extenso - stage II / 2021
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Stage 3 - 01/01/2022 - 30/11/2022 - 146.113 lei
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Designing and manufacturing 3D bioprinted bone constructs based on the nanostructured hydrogels formulated formerly
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During this stage, the project team successfully designed and developed a series of printable nanocomposite formulations using complex compositional systems based on a protein / polysaccharide matrix double reinforced with nano-additives based on polyhedral silsesquioxanes (POSS nanostructured compounds with organic groups) nanocellulose fibrils (CNF). The macromolecular components of natural origin (gelatin, pectin) were previously chemically modified in a convenient way with methacrylate groups (with controlled degree of functionalization) so that the gelation of the final systems is carried out by a photocrosslinking reaction (in the presence of UV radiation and a specific photoinitiator). Multicomponent hydrogels were loaded with cells and osteogenic signal biomolecules (BMP) and with the help of "cell-friendly" extrusion bioprinting technology, a series of 3D substrates were manufactured, which were later evaluated from the physical, chemical and biological properties point of view. Histological evaluation after in vivo testing of the materials demonstrates that the material containing Poss1 and enriched with BMP is a "bioinspired" material, being itself osteoinductive, so that ectopically implanted in mice is able, by itself, to recruit host cells that invade the 3D network of the scaffold and stimulate bone augmentation, probably as a result of the synergistic osteogenic properties given by its composition.
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