scholarly journals Development and Characterisation of a Photocurable Alginate Bioink for 3D Bioprinting

2019 ◽  
Vol 5 (2) ◽  
pp. 12 ◽  
Author(s):  
Mishbak H. H ◽  
Glen Cooper ◽  
Paulo Jorge Da Silva Bartolo
Keyword(s):  
Biomedical Applications ◽  
Uv Light ◽  
Reaction Times ◽  
Rheological Behaviour ◽  
3D Bioprinting ◽  
Alginate Hydrogel ◽  
Chemically Modified ◽  
Mild Conditions ◽  
Biocompatible Material

Alginate is a biocompatible material suitable for biomedical applications, which can be processed under mild conditions upon irradiation.  This paper investigates the preparation and the rheological behaviour of different pre-polymerised and polymerised alginate-methacrylate systems for 3D photopolymerisation bioprinting. The effect of the functionalization time on the mechanical, morphological, swelling and degradation characteristics of crosslinked alginate hydrogel is also discussed.  Alginate was chemically-modified with methacrylate groups and different reaction times considered. Photocurable alginate systems were prepared  by dissolving functionalized alginate with 0.5-1.5% photoinitiator solution and crosslinked by ultraviolet (UV) light (8 mW/cm2).

scholarly journals Chitosans for Tissue Repair and Organ Three-Dimensional (3D) Bioprinting

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 765 ◽  
Author(s):  
Shenglong Li ◽  
Xiaohong Tian ◽  
Jun Fan ◽  
Hao Tong ◽  
Qiang Ao ◽  
...  
Keyword(s):  
Tissue Repair ◽  
Biomedical Applications ◽  
Large Scale ◽  
Scale Up ◽  
Three Dimensional ◽  
The Body ◽  
3D Bioprinting ◽  
Chemically Modified ◽  
Excellent Candidate ◽  
Complex Organ

Chitosan is a unique natural resourced polysaccharide derived from chitin with special biocompatibility, biodegradability, and antimicrobial activity. During the past three decades, chitosan has gradually become an excellent candidate for various biomedical applications with prominent characteristics. Chitosan molecules can be chemically modified, adapting to all kinds of cells in the body, and endowed with specific biochemical and physiological functions. In this review, the intrinsic/extrinsic properties of chitosan molecules in skin, bone, cartilage, liver tissue repair, and organ three-dimensional (3D) bioprinting have been outlined. Several successful models for large scale-up vascularized and innervated organ 3D bioprinting have been demonstrated. Challenges and perspectives in future complex organ 3D bioprinting areas have been analyzed.

Microwave-Assisted Decarbonylation of Biomass-Derived Aldehydes Using Pd-Doped Hydrotalcites

2019 ◽  
Author(s):  
Nan An ◽  
Diana Ainembabazi ◽  
Kavya Samudrala ◽  
Christopher Reid ◽  
Kare Wilson ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Reaction Times ◽  
Inverse Correlation ◽  
Mulliken Charge ◽  
Metal Leaching ◽  
Carbonyl Carbon ◽  
Mild Conditions ◽  
Microwave Assisted ◽  
Biomass Processing ◽  
Alcohol Dehydrogenation

<p>Here we report the synthesis, characterization and activity of tunable Pd-doped hydrotalcites (Pd-HTs) for the decarbonylation of furfural, hydroxymethylfurfural (HMF), aromatic and aliphatic aldehydes under microwave conditions. The decarbonylation activity reported is a notable improvement over prior heterogeneous catalysts for this process. Furfural decarbonylation is optimized in a benign solvent compatible with biomass processing - ethanol, under relatively mild conditions and short reaction times. HMF selectively affords excellent yields of furfuryl alcohol with no humin formation, but longer reaction can also afford furan via tandem alcohol dehydrogenation and decarbonylation. Yields of substituted benzaldehydes are related to calculated Mulliken charge of the carbonyl carbon. The activity and selectivity differences can be traced to loading-dependent differences in Pd speciation on the catalysts. Poisoning studies show inverse correlation between Pd loading and metal leaching: Pd-HTs with lowest Pd loading, which consist of highly dispersed and oxidized Pd species, operate heterogeneously with negligible metal leaching. Recycling experiments are consistent with this trend, offering potential for further optimization to improve robustness.</p>

scholarly journals Homocoupling of terminal alkynes catalyzed by CuCl under solvent-free conditions

2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  
Keyword(s):  
Functional Group ◽  
Reaction Times ◽  
Environmentally Friendly ◽  
Solvent Free ◽  
Copper Salt ◽  
Terminal Alkynes ◽  
Mild Conditions ◽  
Solvent Free Conditions ◽  
Environmentally Friendly Process

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

Mechanical Characterization of UV Photopolymerized PMMA with Different Photo-Initiator Concentration

2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar
Keyword(s):  
Mechanical Properties ◽  
Light Source ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Mechanical Characterization ◽  
Uv Light ◽  
Curing Time ◽  
Uv Led ◽  
Pmma Resin

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.

Oligonucleotides carrying nucleoside antimetabolites as potential prodrugs

2021 ◽  
Vol 28 ◽  
Author(s):  
Carme Fàbrega ◽  
Anna Clua ◽  
Ramon Eritja ◽  
Anna Aviñó
Keyword(s):  
Antisense Oligonucleotides ◽  
Biomedical Applications ◽  
Enzymatic Degradation ◽  
Research Effort ◽  
Synergetic Effect ◽  
Chemotherapeutic Agents ◽  
Dna Nanostructures ◽  
Chemically Modified ◽  
Near Future ◽  
Large Research

Background: Nucleoside and nucleobase antimetabolites are an important class of chemotherapeutic agents for the treatment of cancer as well as other diseases. Introduction: In order to avoid undesirable side effects, several prodrug strategies have been developed for that purpose. In the present review, we describe a relatively unknown strategy that consists in the use of oligonucleotides modified with nucleoside antimetabolites as prodrugs. Method: The active nucleotides are generated by enzymatic degradation once incorporated into cells. This strategy has attracted large interest and is very active at present due to the continuous developments made on therapeutic oligonucleotides and the recent advances in the field of nanomaterials and nanomedicine. Results: A large research effort was done mainly in the improvement of the antiproliferative properties of nucleoside homopolymers, but recently, chemically modified aptamers, antisense oligonucleotides and/or siRNA carrying antiproliferative nucleotides have demonstrated a great potential due to the synergetic effect of both therapeutic entities. In addition, DNA nanostructures with interesting properties have been built to combine antimetabolites and enhancers of cellular uptake in the same scaffold. Finally, protein nanoparticles functionalized with receptor-binders and antiproliferative oligomers represent a new avenue for a more effective treatment in cancer therapy. Conclusion: It is expected that oligonucleotides carrying nucleoside antimetabolites will be considered as potential drugs in the near future for biomedical applications.

scholarly journals Ultra-Small Pd(0) Nanoparticles into a Designed Semisynthetic Lipase: An Efficient and Recyclable Heterogeneous Biohybrid Catalyst for the Heck Reaction under Mild Conditions

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2358 ◽  
Author(s):  
David Lopez-Tejedor ◽  
Blanca de las Rivas ◽  
Jose M. Palomo
Keyword(s):  
Catalytic Activity ◽  
Protein Structure ◽  
Heck Reaction ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Chemically Modified ◽  
Mild Conditions ◽  
In Situ Formation ◽  
Geobacillus Thermocatenulatus

A novel heterogeneous enzyme-palladium (Pd) (0) nanoparticles (PdNPs) bionanohybrid has been synthesized by an efficient, green, and straightforward methodology. A designed Geobacillus thermocatenulatus lipase (GTL) variant genetically and then chemically modified by the introduction of a tailor-made cysteine-containing complementary peptide- was used as the stabilizing and reducing agent for the in situ formation of ultra-small PdNPs nanoparticles embedded on the protein structure. This bionanohybrid was an excellent catalyst in the synthesis of trans-ethyl cinnamate by Heck reaction at 65 °C. It showed the best catalytic performance in dimethylformamide (DMF) containing 10–25% of water as a solvent but was also able to catalyze the reaction in pure DMF or with a higher amount of water as co-solvent. The recyclability and stability were excellent, maintaining more than 90% of catalytic activity after five cycles of use.

scholarly journals Preparation of Cellulose-Based Fluorescent Materials as Coating Pigment by Use of DMSO/DBU/CO2 System

2021 ◽  
Author(s):  
Qinghua Cao ◽  
Jinyue Dai ◽  
Xin Bao ◽  
Zhenyu Zhang ◽  
Fei Liu ◽  
...  
Keyword(s):  
Uv Light ◽  
Tensile Modulus ◽  
Coating Film ◽  
Coating Films ◽  
Fluorescence Response ◽  
Mild Conditions ◽  
Fluorescent Materials ◽  
Bright Color ◽  
Molecular Skeleton ◽  
Quenching Phenomenon

Abstract A series of cellulose-based fluorescent materials are prepared under relative mild conditions by use of the DMSO/DBU/CO2 system to utilize as coating pigments. Through the observation under 365nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~39% and ~66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO2 system provides a feasible way to develop the functional application of cellulose.

scholarly journals Plant-Derived Biomaterials: A Review of 3D Bioprinting and Biomedical Applications

2019 ◽  
Vol 5 ◽  
Author(s):  
Thomas H. Jovic ◽  
Garikai Kungwengwe ◽  
Adam C. Mills ◽  
Iain S. Whitaker
Keyword(s):  
Biomedical Applications ◽  
3D Bioprinting

scholarly journals Fabrication of 3D Printing Scaffold with Porcine Skin Decellularized Bio-Ink for Soft Tissue Engineering

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3522
Author(s):  
Su Jeong Lee ◽  
Jun Hee Lee ◽  
Jisun Park ◽  
Wan Doo Kim ◽  
Su A Park
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
3D Printing ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Research Groups ◽  
Porcine Skin ◽  
Alginate Hydrogel ◽  
Chemical Treatments ◽  
Soft Tissue Engineering

Recently, many research groups have investigated three-dimensional (3D) bioprinting techniques for tissue engineering and regenerative medicine. The bio-ink used in 3D bioprinting is typically a combination of synthetic and natural materials. In this study, we prepared bio-ink containing porcine skin powder (PSP) to determine rheological properties, biocompatibility, and extracellular matrix (ECM) formation in cells in PSP-ink after 3D printing. PSP was extracted without cells by mechanical, enzymatic, and chemical treatments of porcine dermis tissue. Our developed PSP-containing bio-ink showed enhanced printability and biocompatibility. To identify whether the bio-ink was printable, the viscosity of bio-ink and alginate hydrogel was analyzed with different concentration of PSP. As the PSP concentration increased, viscosity also increased. To assess the biocompatibility of the PSP-containing bio-ink, cells mixed with bio-ink printed structures were measured using a live/dead assay and WST-1 assay. Nearly no dead cells were observed in the structure containing 10 mg/mL PSP-ink, indicating that the amounts of PSP-ink used were nontoxic. In conclusion, the proposed skin dermis decellularized bio-ink is a candidate for 3D bioprinting.

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