11,785 results match your criteria form macromolecular


Extraction, Purification, Bioactivities and Application of Matrix Proteins From Pearl Powder and Nacre Powder: A Review.

Front Bioeng Biotechnol 2021 20;9:649665. Epub 2021 Apr 20.

College of Food Science and Technology, Zhejiang University of Technology, Hangzhou, China.

Natural pearls are formed when sand or parasites (irritants) accidentally enter into the oyster body and form pearls under the cover of the nacre layer. Pearl powder is a powdery substance by grinding pearls into small grains, however, the nacre powder is the inner layer of outer corner layer and middle prism layer. Pearl medicine in China has a history of more than 2,000 years, pearl has the effects of calming the mind, clearing the eyes, detoxifying the muscle and so on. Read More

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Reversible multilayered vesicle-like structures with fluid hydrophobic and interpolyelectrolyte layers.

J Colloid Interface Sci 2021 Apr 20;599:313-325. Epub 2021 Apr 20.

Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 00 Prague 2, Czech Republic. Electronic address:

Hydrophobic blocks of amphiphilic block copolymers often form glassy micellar cores at room temperature with a rigid structure that limits their applications as nanocapsules for targeted delivery. Nevertheless, we prepared and analyzed core/shell micelles with a soft core, formed by a self-assembled block copolymer consisting of a hydrophobic block and a polycation block, poly(lauryl acrylate)-block-poly(trimethyl-aminoethyl acrylate) (PLA-QPDMAEA), in aqueous solution. By light and small-angle neutron scattering, by transmission electron microscopy and by fluorescence spectroscopy, we showed that these core/shell micelles are spherical and cylindrical with a fluid-like PLA core and a positively charged outer shell and that they can encapsulate and release hydrophobic solutes. Read More

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Glycerol-Based Dendrimer Nanocomposite Film as a Tunable pH-Sensor for Food Packaging.

ACS Appl Mater Interfaces 2021 May 6. Epub 2021 May 6.

Department of Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 1741 Museum Road, Gainesville, Florida 32611, United States.

Large amounts of food are wasted during the food supply chain. This loss is in part due to consumer confusion over dates on food packages that can indicate a variety of quality indicators in the product (e.g. Read More

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Controlling Structure with Injectable Biomaterials to Better Mimic Tissue Heterogeneity and Anisotropy.

Adv Healthc Mater 2021 May 5:e2002221. Epub 2021 May 5.

Institute of Technical and Macromolecular Chemistry (ITMC), Polymeric Biomaterials, RWTH University Aachen, Worringerweg 2, Aachen, 52074, Germany.

Tissue regeneration of sensitive tissues calls for injectable scaffolds, which are minimally invasive and offer minimal damage to the native tissues. However, most of these systems are inherently isotropic and do not mimic the complex hierarchically ordered nature of the native extracellular matrices. This review focuses on the different approaches developed in the past decade to bring in some form of anisotropy to the conventional injectable tissue regenerative matrices. Read More

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The Protein Data Bank Archive.

Methods Mol Biol 2021 ;2305:3-21

BioMagResBank, Biochemistry Department, University of Wisconsin-Madison, Madison, WI, USA.

Protein Data Bank is the single worldwide archive of experimentally determined macromolecular structure data. Established in 1971 as the first open access data resource in biology, the PDB archive is managed by the worldwide Protein Data Bank (wwPDB) consortium which has four partners-the RCSB Protein Data Bank (RCSB PDB; rcsb.org), the Protein Data Bank Japan (PDBj; pdbj. Read More

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January 2021

Composition-dependent phase transformation in side-chain liquid crystalline copolymers with mesogenic groups at different substituent positions.

Soft Matter 2021 May;17(17):4594-4603

Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.

Copolymerization is an effective approach to tailor the thermal and structural properties of liquid crystalline polymer materials, which is essential for various applications. In this work, two series of polynorbornene copolymers, A-r-B and A-r-C, with the biphenyl mesogenic side group at different substituent positions were synthesized via ring-opening metathesis polymerization in various compositions. The corresponding homopolymers A and C are liquid crystalline polymers, exhibiting an oblique columnar structure (Colob/p2) and lamellar structure, respectively, while homopolymer B is amorphous. Read More

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Detection of polymer compatibility by means of self-organization: poly(ethylene oxide) and poly(sodium 4-styrenesulfonate).

Soft Matter 2021 May 4. Epub 2021 May 4.

Johannes Gutenberg-Universität Mainz, Department Chemie, Jakob-Welder Weg 11, D-55099 Mainz, Germany.

Information on the miscibility of different polymers A and B on a molecular level is important in many ways. However, along the traditional lines this knowledge is difficult and time consuming to achieve. The current study presents a simple alternative, based on the determination of the intrinsic viscosities (specific hydrodynamic volume of isolated coils) for blend solutions in a common solvent. Read More

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Development of a focused high-energy macromolecular ion beam.

Analyst 2021 May;146(9):2936-2944

Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan. and Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.

In this work, we report the development of a focused macromolecular ion beam with kinetic energy of up to 110 keV. The system consists of a quadrupole ion trap (QIT), einzel lens and linear accelerator (LINAC). Based on the combination of matrix-assisted laser desorption ionization (MALDI) and quadrupole ion trapping (QIT), ions were desorbed from the surface and trapped with an ion trap to form biomolecular ion packets. Read More

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Drug -driven self-assembly of pH-sensitive nano-vesicles with high loading capacity and anti-tumor efficacy.

Biomater Sci 2021 May;9(9):3348-3361

Ministry of Education (MOE), Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.

The in vivo delivery of nanomedicine is severely hampered by the limited enhanced permeability and retention effect (EPR) in tumors. Aiming at overcoming this limitation and achieving high anti-tumor effect of chemotherapeutics, we specially addressed an available strategy from a viewpoint of increasing the drug loading of nano-carriers. Here, we constructed a novel pH-responsive polymersome based on the drug-driven self-assembly of amphiphilic polyphosphazenes PAP containing the ortho ester group ABD and mPEG2000. Read More

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Oral administration co-delivery nanoparticles of docetaxel and bevacizumab for improving intestinal absorption and enhancing anticancer activity.

Mater Sci Eng C Mater Biol Appl 2021 May 20;124:112039. Epub 2021 Mar 20.

Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, China. Electronic address:

In this study, to improve the intestinal absorption of small molecule chemotherapeutic drug docetaxel (DTX) and macromolecular monoclonal antibody drug bevacizumab (BVZ), we designed and prepared a type of co-delivery nanoparticles for the oral administration of DTX and BVZ. Carboxymethyl chitosan (CMC) and poly(lactic-co-glycolic acid) (PLGA) were used as the carrier of DTX nanoparticles (CPNP), and methoxy polyethylene glycol-poly (β-amino ester) (mPEG-PAE) was used as the carrier of BVZ nanoparticles (PPNP). Then, the two nanoparticles were physically mixed in mass ratios to form mixed co-delivery nanoparticles, which was named as CPNP&PPNP. Read More

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Hybridization of Step-/Chain-Growth and Radical/Cationic Polymerizations Using Thioacetals as Key Components for Triblock, Periodic and Random Multiblock Copolymers with Thermoresponsiveness.

Macromol Rapid Commun 2021 May 4:e2100192. Epub 2021 May 4.

Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.

A novel strategy for synthesizing a series of multiblock copolymers is developed by combining radical/cationic step-growth polymerizations of dithiols and divinyl ethers and chain-growth cationic degenerative chain-transfer (DT) polymerizations of vinyl ethers using thioacetals as key components. The combination of radical step-growth polymerization and a cationic thiol-ene reaction or cationic step-growth polymerization enables the synthesis of a series of macro chain-transfer agents (CTAs) composed of poly(thioether) and thioacetal groups at different positions. The resulting products are 1) bifunctional macro CTAs with thioacetal groups at both chain ends, 2) periodic macro CTAs periodically having thioacetal groups in the main chain, and 3) random macro CTAs randomly having thioacetal groups in the main chain. Read More

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Frank-Kasper Phases Self-Assembled from a Linear ABAB Tetrablock Copolymer.

Langmuir 2021 Apr 30. Epub 2021 Apr 30.

Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.

The Frank-Kasper (FK) phases self-assembled from block copolymer systems have attracted abiding interest. In this work, the formation mechanism of the complex FK phases from the self-assembly of simple ABAB tetrablock copolymers is investigated using self-consistent field theory (SCFT). For a typical set of parameter spaces, we utilize SCFT to construct a number of phase diagrams. Read More

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Synthesis and characterization of bis(amine)palladium(II) carboxylate complexes as precursors of palladium nanoparticles.

Dalton Trans 2021 Apr 30. Epub 2021 Apr 30.

Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.

The synthesis and characterization of the adducts of n-alkyl amine and palladium n-alkyl carboxylate, [Pd(R2NH2)2(R1COO)2] (R1 = 1, 7, and 11; R2 = 8, 12, and 16), as precursors for the synthesis of palladium nanoparticles (PdNPs) was carried out via differential scanning calorimetry, FT-IR, Raman and UV-Vis spectroscopy, NMR spectroscopy (1H, 13C pulsed field gradient spin-echo (PGSE), and 13C CP-MAS), and powder X-ray diffraction. Pd n-alkyl carboxylates were obtained by a ligand exchange reaction from palladium acetate and the appropriate aliphatic carboxylic acid. It is proposed that carboxyl moieties in the presence of amine ligands are bound to palladium ions via monodentate bonding as opposed to bridging bidentate coordination of pure palladium carboxylate which exists in the form of polymer aggregates. Read More

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Effect of Posttranslational Modifications on the Structure and Activity of FTO Demethylase.

Int J Mol Sci 2021 Apr 26;22(9). Epub 2021 Apr 26.

Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.

The FTO protein is involved in a wide range of physiological processes, including adipogenesis and osteogenesis. This two-domain protein belongs to the AlkB family of 2-oxoglutarate (2-OG)- and Fe(II)-dependent dioxygenases, displaying -methyladenosine (-meA) demethylase activity. The aim of the study was to characterize the relationships between the structure and activity of FTO. Read More

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Host and Viral Factors Involved in Nuclear Egress of Herpes Simplex Virus 1.

Authors:
Jun Arii

Viruses 2021 04 25;13(5). Epub 2021 Apr 25.

Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.

Herpes simplex virus 1 (HSV-1) replicates its genome and packages it into capsids within the nucleus. HSV-1 has evolved a complex mechanism of nuclear egress whereby nascent capsids bud on the inner nuclear membrane to form perinuclear virions that subsequently fuse with the outer nuclear membrane, releasing capsids into the cytosol. The viral-encoded nuclear egress complex (NEC) plays a crucial role in this vesicle-mediated nucleocytoplasmic transport. Read More

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A Theoretical Model for Release Dynamics of an Antifungal Agent Covalently Bonded to the Chitosan.

Molecules 2021 Apr 6;26(7). Epub 2021 Apr 6.

Department of Obstetrics and Gynecology, "Grigore T. Popa" University of Medicine and Pharmacy Iasi, 16 Universitatii Str., 700115 Iasi, Romania.

The aim of the study was to create a mathematical model useful for monitoring the release of bioactive aldehydes covalently bonded to the chitosan by reversible imine linkage, considered as a polymer-drug system. For this purpose, two hydrogels were prepared by the acid condensation reaction of chitosan with the antifungal 2-formyl-phenyl-boronic acid and their particularities; influencing the release of the antifungal aldehyde by shifting the imination equilibrium to the reagents was considered, i.e. Read More

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Functionalized Peptide Fibrils as a Scaffold for Active Substances in Wound Healing.

Int J Mol Sci 2021 Apr 7;22(8). Epub 2021 Apr 7.

Department of Biomedical Chemistry, Faculty of Chemistry, University of Gdańsk, 80-308 Gdańsk, Poland.

Technological developments in the field of biologically active peptide applications in medicine have increased the need for new methods for peptide delivery. The disadvantage of peptides as drugs is their low biological stability. Recently, great attention has been paid to self-assembling peptides that can form fibrils. Read More

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Synthesis and Biological Screening of New Cyano-Substituted Pyrrole Fused (Iso)Quinoline Derivatives.

Molecules 2021 Apr 3;26(7). Epub 2021 Apr 3.

Department of Chemistry, Faculty of Chemistry, Alexandru Ioan Cuza University of Iași, 11 Carol I, 700506 Iași, Romania.

Several new cyano-substituted derivatives with pyrrolo[1,2-]quinoline and pyrrolo[2,1-]isoquinoline scaffolds were synthesized by the [3 + 2] cycloaddition of (iso)quinolinium ylides to fumaronitrile. The cycloimmonium ylides reacted in situ as 1,3-dipoles with fumaronitrile to selectively form distinct final compounds, depending on the structure of the (iso)quinolinium salt. Eleven compounds were evaluated for their anticancer activity against a panel of 60 human cancer cell lines. Read More

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Chirality Remote Control in Nanoporous Materials by Circularly Polarized Light.

J Am Chem Soc 2021 Apr 29. Epub 2021 Apr 29.

Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.

The ability to dynamically control chirality remains a grand challenge in chemistry. Although many molecules possess chiral isomers, lacking their isolation, for instance during photoisomerization, results in racemic mixtures with suppressed enantiospecific chiral properties. Here, we present a nanoporous solid in which chirality and enantioselective enrichment is induced by circularly polarized light (CPL). Read More

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Photoisomerization-induced patterning of ion-pairing materials based on anionic azobenzene and its complex with a fluorescent π-electronic system.

Chem Commun (Camb) 2021 Apr;57(35):4287-4290

Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 525-8577, Japan.

Large mass transport driven by the difference in the photoisomerization-induced surface tension was demonstrated in ion pairs of anionic azobenzene and a cationic polymer. This material motion enabled fluorescence patterning using a trace amount of photoisomerized azobenzenes in complex form with a π-electronic system. Read More

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Normoxic induction of HIF-1α by adenosine-A R signaling in epicardial stromal cells formed after myocardial infarction.

FASEB J 2021 May;35(5):e21517

Department of Molecular Cardiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.

Myocardial infarction (MI) activates the epicardium to form epicardial stromal cells (EpiSC) that reside in the epicardial hypoxic microenvironment. Paracrine factors secreted by EpiSC were shown to modulate the injury response of the post-MI heart and improve cardiac function. We have previously reported that the expression of the angiogenic cytokines vascular endothelial growth factor A (VEGFA) and IL-6 is strongly upregulated in EpiSC by adenosine acting via the A receptor (A R). Read More

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Toward a microscopic model of light absorbing dissolved organic compounds in aqueous environments: theoretical and experimental study.

Phys Chem Chem Phys 2021 May;23(17):10487-10497

Department of Chemistry, University of California, Irvine, CA 92697, USA. and Institute of Chemistry and Fritz Haber Research Center, Hebrew University of Jerusalem, Jerusalem 91904, Israel.

Water systems often contain complex macromolecular systems that absorb light. In marine environments, these light absorbing components are often at the air-water interface and can participate in the chemistry of the atmosphere in ways that are poorly understood. Understanding the photochemistry and photophysics of these systems represents a major challenge since their composition and structures are not unique. Read More

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Study on Acute Toxicity of Amiodarone New Complexes With Cyclodextrin.

Front Pharmacol 2021 4;12:640705. Epub 2021 Mar 4.

Department of Pharmacology, Faculty of Medicine, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania.

Amiodarone low solubility and high permeability is the limiting step for its bioavailability, therefore new formulations are needed to improve the solubility of amiodarone either to increase its oral bioavailability or to reduce its toxic effects. Complexation of amiodarone with cyclodextrin results in improved dissolution rate, solubility, and allows for a more controlled drug release. We characterized the acute toxicity of a new amiodarone 2-hydroxypropyl-β-cyclodextrin complex (AMD/HP-β-CD) as powdered form and as a matrix based on Kollidon® and chitosan, administered intraperitoneally in laboratory animals. Read More

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Convergent synthesis of diversified reversible network leads to liquid metal-containing conductive hydrogel adhesives.

Nat Commun 2021 04 23;12(1):2407. Epub 2021 Apr 23.

Technische Universität Dresden, B CUBE Center for Molecular Bioengineering, Dresden, Germany.

Many features of extracellular matrices, e.g., self-healing, adhesiveness, viscoelasticity, and conductivity, are associated with the intricate networks composed of many different covalent and non-covalent chemical bonds. Read More

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Investigation of the effects of two major secretory granules components, insulin and zinc, on human-IAPP amyloid aggregation and membrane damage.

Chem Phys Lipids 2021 Apr 19;237:105083. Epub 2021 Apr 19.

Biophysics Program, Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA. Electronic address:

Human islet amyloid polypeptide (hIAPP) is a highly amyloidogenic peptide found in pancreatic islets of type-2 diabetes (T2D) patients. Under certain conditions, hIAPP is able to form amyloid fibrils that play a role in the progression of T2D. hIAPP is synthesized in the β-cell of the pancreas and stored in the secretory granules before being released into the extracellular compartment. Read More

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On the mechanism of effectively chiral-pure macromolecular spiralization induced by a weakly chiral polarized heterochiral solution of a chiral compound.

Chirality 2021 Jun 20;33(6):315-320. Epub 2021 Apr 20.

Laboratory of Chemical Physics Of Biosystems, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia.

There has been made an assumption, correlating with experimental data, that the phenomenon of effectively chiral-pure, chiral-induced spiralization of macromolecules in weakly polarized heterochiral solutions is determined by the mechanism of physico-chemical annihilation: enantiomers-antipodes of a chiral compound in a heterochiral solution annihilate; that is, they form achiral dimers, the solution becomes effectively homochiral and further, chiral-induced macromolecular spiralization of one sign of helicity is realized in it in the same way as in other homochiral solutions. Read More

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Intelligent nanogels with self-adaptive responsiveness for improved tumor drug delivery and augmented chemotherapy.

Bioact Mater 2021 Oct 24;6(10):3473-3484. Epub 2021 Mar 24.

College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.

For cancer nanomedicine, the main goal is to deliver therapeutic agents effectively to solid tumors. Here, we report the unique design of self-adaptive ultrafast charge-reversible chitosan-polypyrrole nanogels (CH-PPy NGs) for enhanced tumor delivery and augmented chemotherapy. CH was first grafted with PPy to form CH-PPy polymers that were used to form CH-PPy NGs through glutaraldehyde cross-linking a miniemulsion method. Read More

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October 2021

The Enigma of Interspecific Plasmodesmata: Insight From Parasitic Plants.

Front Plant Sci 2021 1;12:641924. Epub 2021 Apr 1.

Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.

Parasitic plants live in intimate physical connection with other plants serving as their hosts. These host plants provide the inorganic and organic compounds that the parasites need for their propagation. The uptake of the macromolecular compounds happens through symplasmic connections in the form of plasmodesmata. Read More

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Solvent Selectivity Governs the Emergence of Temperature Responsiveness in Block Copolymer Self-Assembly.

Macromolecules 2021 Mar 4;54(6):2912-2920. Epub 2021 Mar 4.

Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.

In highly selective solvents, block copolymers (BCPs) form association colloids, while in solvents with poor selectivity, they exhibit a temperature-controlled (de)mixing behavior. Herein, it is shown that a temperature-responsive self-assembly behavior emerges in solvent mixtures of intermediate selectivity. A biocompatible poly-ethylene(oxide)--poly-ε-caprolactone (PEO-PCL) BCP is used as a model system. Read More

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Physically-cross-linked poly(vinyl alcohol) cell culture plate coatings facilitate preservation of cell-cell interactions, spheroid formation, and stemness.

J Biomed Mater Res B Appl Biomater 2021 Apr 13. Epub 2021 Apr 13.

Department of Molecular Biology & Microbiology, Case Western Reserve University, Cleveland, Ohio, USA.

We employed aqueous solutions of highly-hydrolyzed (>99+%) poly(vinyl alcohol), PVA, to coat plastic dishes as a method to efficiently induce three-dimensional (3D) culturing of cells. The coatings were prepared by simple evaporation of 3 wt/vol% solutions of PVA in water and require no additional processing steps after air drying under sterile conditions. The coating allows spheroids to form in solution. Read More

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