scholarly journals Optimization of Polydopamine Coatings onto Poly–ε–Caprolactone Electrospun Fibers for the Fabrication of Bio-Electroconductive Interfaces

2020 ◽  
Vol 11 (1) ◽  
pp. 19 ◽  
Author(s):  
Simona Zuppolini ◽  
Iriczalli Cruz-Maya ◽  
Vincenzo Guarino ◽  
Anna Borriello
Keyword(s):  
Self Assembly ◽  
Fluid Dynamic ◽  
Electrospun Fibers ◽  
Oxidation Reactions ◽  
Mussel Adhesive Proteins ◽  
Mussel Adhesive ◽  
Adhesive Proteins ◽  
Conductive Properties

In recent years, mussel adhesive proteins have attracted much attention because they can form strong adhesive interface interactions with various substrates in a wet environment. Inspired by their catechol- and amine-based molecular structure, polydopamine (PDA), a dopamine derived synthetic eumelanin polymer, was recognized as a suitable bio-interface coating. PDA was successfully used to improve adhesion due to the availability of copious functional groups for covalently immobilizing biomolecules and anchoring reactive species and ions. Recently, it has been demonstrated that PDA and its derivatives can be successfully used for the surface modification of implants interfaces to modulate in vitro cellular responses in order to enhance the in vivo functionality of biomedical implants (i.e., prosthesis). Herein, we propose the development of multifunctional scaffolds based on polyε–caprolactone (PCL) electrospun fibers coated with PDA via electro fluid dynamic methods, by optimizing polymerization/oxidation reactions capable of driving PDA self–assembly, and, ultimately, investigating the effects on cell response. Morphological analyses have confirmed the possibility to obtain different surface topographies as a function of the coating process while in vitro studies proved the ability of PDA coating to interact with cells no compromising in vitro viability. In perspective, in vitro conductive properties of fibers will be further investigated in order to validate their promising use as bioconductive interfaces for tissue engineering applications.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Programmable in vitro Co-Encapsidation of Guest Proteins Inside Protein Nanocages

2018 ◽  
Author(s):  
Noor H. Dashti ◽  
Rufika S. Abidin ◽  
Frank Sainsbury
Keyword(s):  
Self Assembly ◽  
Mammalian Cells ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Super Resolution ◽  
Cell Engineering ◽  
Particle Analysis ◽  
Protein Cages

Bioinspired self-sorting and self-assembling systems using engineered versions of natural protein cages have been developed for biocatalysis and therapeutic delivery. The packaging and intracellular delivery of guest proteins is of particular interest for both <i>in vitro</i> and <i>in vivo</i> cell engineering. However, there is a lack of platforms in bionanotechnology that combine programmable guest protein encapsidation with efficient intracellular uptake. We report a minimal peptide anchor for <i>in vivo</i> self-sorting of cargo-linked capsomeres of the Murine polyomavirus (MPyV) major coat protein that enables controlled encapsidation of guest proteins by <i>in vitro</i> self-assembly. Using Förster resonance energy transfer (FRET) we demonstrate the flexibility in this system to support co-encapsidation of multiple proteins. Complementing these ensemble measurements with single particle analysis by super-resolution microscopy shows that the stochastic nature of co-encapsidation is an overriding principle. This has implications for the design and deployment of both native and engineered self-sorting encapsulation systems and for the assembly of infectious virions. Taking advantage of the encoded affinity for sialic acids ubiquitously displayed on the surface of mammalian cells, we demonstrate the ability of self-assembled MPyV virus-like particles to mediate efficient delivery of guest proteins to the cytosol of primary human cells. This platform for programmable co-encapsidation and efficient cytosolic delivery of complementary biomolecules therefore has enormous potential in cell engineering.

scholarly journals Development of In Situ Self-Assembly Nanoparticles to Encapsulate Lopinavir and Ritonavir for Long-Acting Subcutaneous Injection

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 904
Author(s):  
Irin Tanaudommongkon ◽  
Asama Tanaudommongkon ◽  
Xiaowei Dong
Keyword(s):  
Sustained Release ◽  
Trough Concentration ◽  
Self Assembly ◽  
Subcutaneous Injection ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Long Acting

Most antiretroviral medications for human immunodeficiency virus treatment and prevention require high levels of patient adherence, such that medications need to be administered daily without missing doses. Here, a long-acting subcutaneous injection of lopinavir (LPV) in combination with ritonavir (RTV) using in situ self-assembly nanoparticles (ISNPs) was developed to potentially overcome adherence barriers. The ISNP approach can improve the pharmacokinetic profiles of the drugs. The ISNPs were characterized in terms of particle size, drug entrapment efficiency, drug loading, in vitro release study, and in vivo pharmacokinetic study. LPV/RTV ISNPs were 167.8 nm in size, with a polydispersity index of less than 0.35. The entrapment efficiency was over 98% for both LPV and RTV, with drug loadings of 25% LPV and 6.3% RTV. A slow release rate of LPV was observed at about 20% on day 5, followed by a sustained release beyond 14 days. RTV released faster than LPV in the first 5 days and slower than LPV thereafter. LPV trough concentration remained above 160 ng/mL and RTV trough concentration was above 50 ng/mL after 6 days with one subcutaneous injection. Overall, the ISNP-based LPV/RTV injection showed sustained release profiles in both in vitro and in vivo studies.

scholarly journals Engineering of Biofilms with a Glycosylation Circuit for Biomaterial Applications

2021 ◽  
Author(s):  
Ebru Sahin Kehribar ◽  
Musa E İsilak ◽  
Eray U. Bozkurt ◽  
Jozef Adamcik ◽  
Raffaele Mezzenga ◽  
...  
Keyword(s):  
Spider Silk ◽  
Post Translational Modification ◽  
Adhesive Protein ◽  
Mussel Adhesive Proteins ◽  
Wide Range ◽  
Mussel Adhesive ◽  
Adhesive Proteins ◽  
Glycosylated Proteins

Glycosylation is a crucial post-translational modification for a wide range of functionalities. Adhesive protein-based biomaterials in nature rely on heavily glycosylated proteins such as spider silk and mussel adhesive proteins....

scholarly journals Force generation by protein–DNA co-condensation

2021 ◽  
Author(s):  
Thomas Quail ◽  
Stefan Golfier ◽  
Maria Elsner ◽  
Keisuke Ishihara ◽  
Vasanthanarayan Murugesan ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Self Assembly ◽  
Spider Silk ◽  
Regulatory Elements ◽  
Heterochromatin Formation ◽  
First Order Phase Transition ◽  
Dna Strand ◽  
First Order Phase

AbstractInteractions between liquids and surfaces generate forces1,2 that are crucial for many processes in biology, physics and engineering, including the motion of insects on the surface of water3, modulation of the material properties of spider silk4 and self-assembly of microstructures5. Recent studies have shown that cells assemble biomolecular condensates via phase separation6. In the nucleus, these condensates are thought to drive transcription7, heterochromatin formation8, nucleolus assembly9 and DNA repair10. Here we show that the interaction between liquid-like condensates and DNA generates forces that might play a role in bringing distant regulatory elements of DNA together, a key step in transcriptional regulation. We combine quantitative microscopy, in vitro reconstitution, optical tweezers and theory to show that the transcription factor FoxA1 mediates the condensation of a protein–DNA phase via a mesoscopic first-order phase transition. After nucleation, co-condensation forces drive growth of this phase by pulling non-condensed DNA. Altering the tension on the DNA strand enlarges or dissolves the condensates, revealing their mechanosensitive nature. These findings show that DNA condensation mediated by transcription factors could bring distant regions of DNA into close proximity, suggesting that this physical mechanism is a possible general regulatory principle for chromatin organization that may be relevant in vivo.

scholarly journals Dissecting the Structure-Function Relationship of a Fungicidal Peptide Derived from the Constant Region of Human Immunoglobulins

2016 ◽  
Vol 60 (4) ◽  
pp. 2435-2442 ◽  
Author(s):  
Tecla Ciociola ◽  
Thelma A. Pertinhez ◽  
Laura Giovati ◽  
Martina Sperindè ◽  
Walter Magliani ◽  
...  
Keyword(s):  
Self Assembly ◽  
Galleria Mellonella ◽  
Critical Role ◽  
Yeast Cells ◽  
Therapeutic Effects ◽  
Constant Region ◽  
Content Type ◽  
Complementarity Determining Regions

ABSTRACTSynthetic peptides encompassing sequences related to the complementarity-determining regions of antibodies or derived from their constant region (Fc peptides) were proven to exert differential antimicrobial, antiviral, antitumor, and/or immunomodulatory activitiesin vitroand/orin vivo, regardless of the specificity and isotype of the parental antibody. Alanine substitution derivatives of these peptides exhibited unaltered, increased, or decreased candidacidal activitiesin vitro. The bioactive IgG-derived Fc N10K peptide (NQVSLTCLVK) spontaneously self-assembles, a feature previously recognized as relevant for the therapeutic activity of another antibody-derived peptide. We evaluated the contribution of each residue to the peptide self-assembling capability by circular-dichroism spectroscopy. The interaction of the N10K peptide and its derivatives withCandida albicanscells was studied by confocal, transmission, and scanning electron microscopy. The apoptosis and autophagy induction profiles in yeast cells treated with the peptides were evaluated by flow cytometry, and the therapeutic efficacy against candidal infection was studied in aGalleria mellonellamodel. Overall, the results indicate a critical role for some residues in the self-assembly process and a correlation of that capability with the candidacidal activities of the peptidesin vitroand their therapeutic effectsin vivo.

scholarly journals Charge influences substrate recognition and self-assembly of hydrophobic FG sequences

2016 ◽  
Author(s):  
Wesley G. Chen ◽  
Jacob Witten ◽  
Scott C. Grindy ◽  
Niels Holten-Andersen ◽  
Katharina Ribbeck
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Amino Acid Sequences ◽  
Nuclear Pore ◽  
Selective Binding ◽  
Charged Amino Acids ◽  
Essential Components ◽  
Transport Receptors

AbstractThe nuclear pore complex controls the passage of molecules via hydrophobic phenylalanine-glycine (FG) domains on nucleoporins. Such FG-domains consist of repeating units of FxFG, FG, or GLFG sequences, which can be interspersed with highly charged amino acid sequences. Despite the high density of charge exhibited in certain FG-domains, if and how charge influences FG-domain self-assembly and selective binding of nuclear transport receptors is largely unexplored. Studying how individual charged amino acids contribute to nuclear pore selectivity is challenging with modern in vivo and in vitro techniques due to the complexity of nucleoporin sequences. Here, we present a rationally designed approach to deconstruct essential components of nucleoporins down to 14 amino acid sequences. With these nucleoporin-based peptides, we systematically dissect how charge type and placement of charge influences self-assembly and selective binding of FG-containing gels. Specifically, we find that charge type determines which hydrophobic substrates FG sequences recognize while spatial localization of charge tunes hydrophobic self-assembly and receptor selectivity of FG sequences.

scholarly journals Structure-Antifouling Activity Relationship and Molecular Targets of Bio-Inspired(thio)xanthones

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1126 ◽  
Author(s):  
Joana R. Almeida ◽  
Andreia Palmeira ◽  
Alexandre Campos ◽  
Isabel Cunha ◽  
Micaela Freitas ◽  
...  
Keyword(s):  
Acetylcholinesterase Activity ◽  
Qsar Model ◽  
Artemia Salina ◽  
Activity Relationship ◽  
Predictive Capacity ◽  
Antifouling Activity ◽  
In Silico Studies ◽  
Mussel Adhesive

The development of alternative ecological and effective antifouling technologies is still challenging. Synthesis of nature-inspired compounds has been exploited, given the potential to assure commercial supplies of potential ecofriendly antifouling agents. In this direction, the antifouling activity of a series of nineteen synthetic small molecules, with chemical similarities with natural products, were exploited in this work. Six (4, 5, 7, 10, 15 and 17) of the tested xanthones showed in vivo activity toward the settlement of Mytilus galloprovincialis larvae (EC50: 3.53–28.60 µM) and low toxicity to this macrofouling species (LC50 > 500 µM and LC50/EC50: 17.42–141.64), and two of them (7 and 10) showed no general marine ecotoxicity (<10% of Artemia salina mortality) after 48 h of exposure. Regarding the mechanism of action in mussel larvae, the best performance compounds 4 and 5 might be acting by the inhibition of acetylcholinesterase activity (in vitro and in silico studies), while 7 and 10 showed specific targets (proteomic studies) directly related with the mussel adhesive structure (byssal threads), given by the alterations in the expression of Mytilus collagen proteins (PreCols) and proximal thread proteins (TMPs). A quantitative structure-activity relationship (QSAR) model was built with predictive capacity to enable speeding the design of new potential active compounds.

scholarly journals Self‐Assembly of Pseudo‐Isocyanine Chloride as a Sensor for Macromolecular Crowding In Vitro and In Vivo

2020 ◽  
Vol 26 (31) ◽  
pp. 7041-7050
Author(s):  
Benjamin Hämisch ◽  
Roland Pollak ◽  
Simon Ebbinghaus ◽  
Klaus Huber
Keyword(s):  
Self Assembly ◽  
Macromolecular Crowding
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