Preparation of cellulose nanofiber-reinforced gelatin hydrogel and optimization for 3D printing applications

Gelatin (GEL) obtained from animals is famous for its biocompatibility and biodegradability. However, its poor mechanical properties limits possible applications as bio-inks to fabricate tissue scaffolds through three-dimensional (3D) printing. In this work, a high strength hydrogel based on cellulose nanofibers and GEL (CNF/GEL) was designed for 3D printing. Scanning electron microscopy and breaking strength results indicated that a CNF filling content of 10% was the best content in the CNF/GEL hydrogels. The rheological properties of the samples with different solid contents were investigated, and the 10%-CNF/GEL-5 hydrogel was proposed for 3D printing. Then, a printing strategy with optimal conditions, including a crosslinking procedure for obtaining a 3D scaffold, was proposed. The biocompatibility of G-10%-CNF/GEL-5 was also investigated using CCK-8 and Hoechst 33342/PI double-staining assays. These results confirmed that the 10%-CNF/GEL-5 composite hydrogel has potential to be used as a 3D bio-ink for application in tissue repair.

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Optically Transparent Nanocomposite Based on Cellulose Nanofibers from Newspapers and Polyurethane

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.174-177.905 ◽

2012 ◽

Vol 174-177 ◽

pp. 905-911 ◽

Cited By ~ 3

Author(s):

Xue Ting Li ◽

Da Gang Li ◽

Li Xu ◽

Yu Mei Wang ◽

Dong Liang Lin

Keyword(s):

Tensile Strength ◽

Elastic Modulus ◽

Cellulose Nanofibers ◽

Three Dimensional ◽

High Strength ◽

Wood Powder ◽

Sem Images ◽

High Transparency ◽

Dimensional Network ◽

Optically Transparent

The goal of this paper was to develop an optically transparent nanocomposite with high strength by reinforcing polyurethane (PU) with cellulose nanofibers (CNFs) extracted from newspapers. The FE-SEM images show that through chemical and mechanical treatments, newspaper CNFs with diameters ranged from 20 to 100 nm and an aspect ratio of over 1000 were successfully obtained as well as wood powder. They were cross-linked together and formed a special three-dimensional network structure. The nanocomposite was fabricated by impregnating the CNF sheet into transparent PU resin and cured under ultraviolet. Results demonstrate that the transparency of newspaper CNF/PU nanocomposite was as high as wood CNF/PU nanocomposite. The elastic modulus and tensile strength of newspaper CNF/PU composite were increased roughly eighteen times and two times respectively while retaining the high transparency of PU, which was nearly the same with wood CNF/PU composite.

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Effects of nanocellulose on alginate/gelatin bio-inks for extrusion-based 3D printing

BioResources ◽

10.15376/biores.15.4.7357-7373 ◽

2020 ◽

Vol 15 (4) ◽

pp. 7357-7373 ◽

Cited By ~ 1

Author(s):

Chenyang Han ◽

Xinyi Wang ◽

Zhongjin Ni ◽

Yihua Ni ◽

Weiwei Huan ◽

...

Keyword(s):

3D Printing ◽

Cellulose Nanofibers ◽

Three Dimensional ◽

Property Testing ◽

Morphological Observation ◽

Shear Rates ◽

Good Biocompatibility ◽

Potential Use ◽

Better Than ◽

Low Shear

Cellulose nanofibers (NFC) have attracted special attention in the field of extrusion-based three-dimensional (3D) bioprinting due to their good biocompatibility, excellent mechanical properties, and outstanding shear-thinning property. In this study, by mixing cellulose nanofibers suspension with sodium alginate (SA) and gelatin (GEL) solution, five groups of composite bio-inks with different NFC concentrations were prepared. The effects of NFC on the performance of the SA/GEL matrix hydrogels were analyzed by morphological observation, rheological property testing, mechanical property testing, swelling property testing, and printability analysis. The rheological results showed that the addition of NFC noticeably increased the viscosity of biological inks with low shear rates; therefore, the printed scaffolds maintained their structure better during the 3D printing process. After crosslinking with calcium chloride (CaCl2), the fidelity of the NFC/SA/GEL composite hydrogel structure was better than that of the SA/GEL hydrogel. Moreover, the structural properties were strengthened, and the mechanical stabilities of the composite hydrogels improved when NFC was added. Therefore, this study provided an easy way to improve the printability of extrusion-based 3D printing and the potential use of nanocellulose.

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Electrically assisted 3D printing of nacre-inspired structures with self-sensing capability

Science Advances ◽

10.1126/sciadv.aau9490 ◽

2019 ◽

Vol 5 (4) ◽

pp. eaau9490 ◽

Cited By ~ 41

Author(s):

Yang Yang ◽

Xiangjia Li ◽

Ming Chu ◽

Haofan Sun ◽

Jie Jin ◽

...

Keyword(s):

3D Printing ◽

Three Dimensional ◽

Hierarchical Structures ◽

High Strength ◽

Mechanical Reinforcement ◽

Resistance Change ◽

Electrically Assisted ◽

Brick And Mortar ◽

3D Printed ◽

3D Shapes

Lightweight and strong structural materials attract much attention due to their strategic applications in sports, transportation, aerospace, and biomedical industries. Nacre exhibits high strength and toughness from the brick-and-mortar–like structure. Here, we present a route to build nacre-inspired hierarchical structures with complex three-dimensional (3D) shapes by electrically assisted 3D printing. Graphene nanoplatelets (GNs) are aligned by the electric field (433 V/cm) during 3D printing and act as bricks with the polymer matrix in between as mortar. The 3D-printed nacre with aligned GNs (2 weight %) shows lightweight property (1.06 g/cm3) while exhibiting comparable specific toughness and strength to the natural nacre. In addition, the 3D-printed lightweight smart armor with aligned GNs can sense its damage with a hesitated resistance change. This study highlights interesting possibilities for bioinspired structures, with integrated mechanical reinforcement and electrical self-sensing capabilities for biomedical applications, aerospace engineering, as well as military and sports armors.

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Trinity of Three-Dimensional (3D) Scaffold, Vibration, and 3D Printing on Cell Culture Application: A Systematic Review and Indicating Future Direction

Bioengineering ◽

10.3390/bioengineering5030057 ◽

2018 ◽

Vol 5 (3) ◽

pp. 57 ◽

Cited By ~ 18

Author(s):

Haobo Yuan ◽

Ke Xing ◽

Hung-Yao Hsu

Keyword(s):

Cell Culture ◽

3D Printing ◽

Rapid Development ◽

Three Dimensional ◽

3D Cell Culture ◽

3D Scaffold ◽

Cell Scaffold ◽

3D Environments ◽

Culturing Conditions ◽

Future Direction

Cell culture and cell scaffold engineering have previously developed in two directions. First can be ‘static into dynamic’, with proven effects that dynamic cultures have benefits over static ones. Researches in this direction have used several mechanical means, like external vibrators or shakers, to approximate the dynamic environments in real tissue, though such approaches could only partly address the issue. Second, can be ‘2D into 3D’, that is, artificially created three-dimensional (3D) passive (also called ‘static’) scaffolds have been utilized for 3D cell culture, helping external culturing conditions mimic real tissue 3D environments in a better way as compared with traditional two-dimensional (2D) culturing. In terms of the fabrication of 3D scaffolds, 3D printing (3DP) has witnessed its high popularity in recent years with ascending applicability, and this tendency might continue to grow along with the rapid development in scaffold engineering. In this review, we first introduce cell culturing, then focus 3D cell culture scaffold, vibration stimulation for dynamic culture, and 3DP technologies fabricating 3D scaffold. Potential interconnection of these realms will be analyzed, as well as the limitations of current 3D scaffold and vibration mechanisms. In the recommendation part, further discussion on future scaffold engineering regarding 3D vibratory scaffold will be addressed, indicating 3DP as a positive bridging technology for future scaffold with integrated and localized vibratory functions.

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Compressive behaviours of octet-truss lattices

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220913586 ◽

2020 ◽

Vol 234 (16) ◽

pp. 3257-3269 ◽

Cited By ~ 1

Author(s):

Yifan Li ◽

Huaiyuan Gu ◽

Martyn Pavier ◽

Harry Coules

Keyword(s):

Failure Modes ◽

Density Ratio ◽

Three Dimensional ◽

Compressive Load ◽

High Strength ◽

Detailed Comparison ◽

Compressive Response ◽

Beam Elements ◽

Structural Applications ◽

Octet Truss

Octet-truss lattice structures can be used for lightweight structural applications due to their high strength-to-density ratio. In this research, octet-truss lattice specimens were fabricated by stereolithography additive manufacturing with a photopolymer resin. The mechanical properties of this structure have been examined in three orthogonal orientations under the compressive load. Detailed comparison and description were carried out on deformation mechanisms and failure modes in different lattice orientations. Finite element models using both beam elements and three-dimensional solid elements were used to simulate the compressive response of this structure. Both the load reaction and collapse modes obtained in simulations were compared with test results. Our results indicate that three-dimensional continuum element models are required to accurately capture the behaviour of real trusses, taking into account the effects of finite-sized beams and joints.

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Efficacy evaluation of three-dimensional printing assisted osteotomy guide plate in accurate osteotomy of adolescent cubitus varus deformity

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-019-1403-7 ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 3

Author(s):

Yuan-Wei Zhang ◽

Xin Xiao ◽

Wen-Cheng Gao ◽

Yan Xiao ◽

Su-Li Zhang ◽

...

Keyword(s):

3D Printing ◽

Blood Loss ◽

Three Dimensional ◽

Operation Time ◽

Varus Deformity ◽

Conventional Group ◽

Intraoperative Blood Loss ◽

Cubitus Varus ◽

Guide Plate ◽

Significant Difference

Abstract Background This present study is aimed to retrospectively assess the efficacy of three-dimensional (3D) printing assisted osteotomy guide plate in accurate osteotomy of adolescent cubitus varus deformity. Material and methods Twenty-five patients (15 males and 10 females) with the cubitus varus deformity from June 2014 to December 2017 were included in this study and were enrolled into the conventional group (n = 11) and 3D printing group (n = 14) according to the different surgical approaches. The operation time, intraoperative blood loss, osteotomy degrees, osteotomy end union time, and postoperative complications between the two groups were observed and recorded. Results Compared with the conventional group, the 3D printing group has the advantages of shorter operation time, less intraoperative blood loss, higher rate of excellent correction, and higher rate of the parents’ excellent satisfaction with appearance after deformity correction (P < 0.001, P < 0.001, P = 0.019, P = 0.023). Nevertheless, no significant difference was presented in postoperative carrying angle of the deformed side and total complication rate between the two groups (P = 0.626, P = 0.371). Conclusions The operation assisted by 3D printing osteotomy guide plate to correct the adolescent cubitus varus deformity is feasible and effective, which might be an optional approach to promote the accurate osteotomy and optimize the efficacy.

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Three-dimensional(3D) printing in forensic science–An emerging technology in India

Annals of 3D Printed Medicine ◽

10.1016/j.stlm.2021.100006 ◽

2021 ◽

Vol 1 ◽

pp. 100006

Author(s):

Gargi Jani ◽

Abraham Johnson ◽

Jeidson Marques ◽

Ademir Franco

Keyword(s):

3D Printing ◽

Forensic Science ◽

Three Dimensional ◽

Emerging Technology

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Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Polymers ◽

10.3390/polym13111841 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1841

Author(s):

Kang Li ◽

Xuejie Zhang ◽

Yan Qin ◽

Ying Li

Keyword(s):

High Efficiency ◽

Sol Gel ◽

Cellulose Nanofibers ◽

Three Dimensional ◽

Good Mechanical Property ◽

Polar Groups ◽

Dimensional Network ◽

Natural Polysaccharide ◽

Valuable Method ◽

Adsorption Capability

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.

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Efficient 3D printing via photooxidation of ketocoumarin based photopolymerization

Nature Communications ◽

10.1038/s41467-021-23170-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xiaoyu Zhao ◽

Ye Zhao ◽

Ming-De Li ◽

Zhong’an Li ◽

Haiyan Peng ◽

...

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Visible Light ◽

Light Exposure ◽

Three Dimensional ◽

3D Printer ◽

Light Penetration ◽

Viable Solution

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.

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Comparative Study of Silk Fibroin-Based Hydrogels and Their Potential as Material for 3-Dimensional (3D) Printing

Molecules ◽

10.3390/molecules26133887 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3887

Author(s):

Watcharapong Pudkon ◽

Chavee Laomeephol ◽

Siriporn Damrongsakkul ◽

Sorada Kanokpanont ◽

Juthamas Ratanavaraporn

Keyword(s):

3D Printing ◽

Silk Fibroin ◽

Biomedical Applications ◽

Mechanical Stability ◽

Three Dimensional ◽

Structure Stability ◽

3 Dimensional ◽

Critical Technology ◽

Box Structure ◽

High Degree

Three-dimensional (3D) printing is regarded as a critical technology in material engineering for biomedical applications. From a previous report, silk fibroin (SF) has been used as a biomaterial for tissue engineering due to its biocompatibility, biodegradability, non-toxicity and robust mechanical properties which provide a potential as material for 3D-printing. In this study, SF-based hydrogels with different formulations and SF concentrations (1–3%wt) were prepared by natural gelation (SF/self-gelled), sodium tetradecyl sulfate-induced (SF/STS) and dimyristoyl glycerophosphorylglycerol-induced (SF/DMPG). From the results, 2%wt SF-based (2SF) hydrogels showed suitable properties for extrusion, such as storage modulus, shear-thinning behavior and degree of structure recovery. The 4-layer box structure of all 2SF-based hydrogel formulations could be printed without structural collapse. In addition, the mechanical stability of printed structures after three-step post-treatment was investigated. The printed structure of 2SF/STS and 2SF/DMPG hydrogels exhibited high stability with high degree of structure recovery as 70.4% and 53.7%, respectively, compared to 2SF/self-gelled construct as 38.9%. The 2SF/STS and 2SF/DMPG hydrogels showed a great potential to use as material for 3D-printing due to its rheological properties, printability and structure stability.

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