Layer-by-layer self-assembly of functionalized graphene nanoplates for glucose sensing in vivo integrated with on-line microdialysis system

2012 ◽  
Vol 32 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Hui Gu ◽  
Yanyan Yu ◽  
Xiaoqian Liu ◽  
Bing Ni ◽  
Tianshu Zhou ◽  
...  
Keyword(s):  
Self Assembly ◽  
Glucose Sensing ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
On Line ◽  
Graphene Nanoplates

scholarly journals Layer-by-Layer Biomaterials for Drug Delivery

2020 ◽  
Vol 22 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Dahlia Alkekhia ◽  
Paula T. Hammond ◽  
Anita Shukla
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Self Assembly ◽  
Controlled Drug Release ◽  
In Vivo Studies ◽  
Layer By Layer ◽  
Microbial Infection ◽  
Multiple Substrates

Controlled drug delivery formulations have revolutionized treatments for a range of health conditions. Over decades of innovation, layer-by-layer (LbL) self-assembly has emerged as one of the most versatile fabrication methods used to develop multifunctional controlled drug release coatings. The numerous advantages of LbL include its ability to incorporate and preserve biological activity of therapeutic agents; coat multiple substrates of all scales (e.g., nanoparticles to implants); and exhibit tuned, targeted, and/or responsive drug release behavior. The functional behavior of LbL films can be related to their physicochemical properties. In this review, we highlight recent advances in the development of LbL-engineered biomaterials for drug delivery, demonstrating their potential in the fields of cancer therapy, microbial infection prevention and treatment, and directing cellular responses. We discuss the various advantages of LbL biomaterial design for a given application as demonstrated through in vitro and in vivo studies.

Hollow Microcapsules Through Layer-by-Layer Self-Assembly of Chitosan/Alginate on E. coli

MRS Advances ◽  
2020 ◽  
Vol 5 (46-47) ◽  
pp. 2401-2407
Author(s):  
Michael Y. Yitayew ◽  
Maryam Tabrizian
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Layer By Layer ◽  
E Coli ◽  
Fluorescence Measurements ◽  
Transmission Electron ◽  
Imaging Probes ◽  
Delivery Platform ◽  
20 Nm

AbstractHollow microcapsules prepared via layer-by-layer (LbL) self-assembled polyelectrolytes are prevalent biomaterials in the synthesis of biocompatible delivery systems for drugs, imaging probes, and other macromolecules to control biodistribution and lower toxicity in vivo. The use of LbL self-assembly for the synthesis of these capsules provides several benefits including ease of fabrication, abundance in choice of substrates and coating material, as well as application-specific tunability. This study explores the development of hollow microcapsules by LbL assembly of chitosan and alginate onto live E. coli cells, and also provides a proof-of-concept of this capsule as a delivery platform through the encapsulation of quantum dots as a cargo. The study found that robust bilayers of chitosan/alginate can be formed onto the core substrate (E. coli) containing quantum dots as demonstrated with zeta potential analysis. Confocal microscopy was used to verify cell viability and the internalization of quantum dots into the cells as well as confirmation of the coating using fluorescein-labelled chitosan. Furthermore, transmission electron microscopy (TEM) was used to analyse cells coated with four-bilayers and showed a uniform coating morphology with a capsule thickness of 10-20 nm, which increased to 20-50 nm for hollow capsules after cell lysis. Quantum dot retention in the capsules was demonstrated using fluorescence measurements. Overall, the study shows promising results of a novel fabrication method for hollow microcapsules that uses biocompatible polymers and mild core dissolution conditions using cell templates with applications in sustained release of therapeutics and imaging probes.

Characterization and Biocompatibility Studies of Layer-by-Layer Self-Assembled Humic Acid/Fe3+ Films

2000 ◽  
Vol 662 ◽  
Author(s):  
Izabela Galeska ◽  
Tammy Hickey ◽  
Francis Moussy ◽  
Fotios Papadimitrakopoulos
Keyword(s):  
Self Assembly ◽  
Strong Dependence ◽  
Tissue Reaction ◽  
Glucose Sensors ◽  
Layer By Layer ◽  
Degree Of Ionization ◽  
Glucose Levels ◽  
Silastic Tubing ◽  
Assembly Technique

AbstractA semipermeable and non-inflammatory membrane is a prerequisite for the development of an implantable biosensor for continuous pain free monitoring of glucose levels in vivo. Humic acids (HAs) have been reported to have therapeutically relevant characteristics such as antiviral and anti-inflammatory.[1] This encouraged us to investigate the in vivo compatibility of HAs based multilayered films as a potential membrane material for implantable glucose sensors. Electrostatic layer-by-layer self-assembly technique of HAs with oppositely charged ferric ions was utilized to grow these films. Quartz Crystal Microbalance (QCM) and ellipsometric studies have shown repeatable, stepwise increase in mass and in film thickness during self-assembly. The growth of these assemblies exhibited strong dependence on pH and ionic strength of HAs solution and was correlated with the degree of ionization of carboxyl groups and the neutralization induced surface spreading. HAs films used in the biocompatibility study were very well tolerated by the tissue and no difference with silastic tubing, used as control, could be observed. All types of samples, including the controls, induced similar long-term tissue reaction showing almost no inflammation and a light to moderate fibrosis with some blood vessels present.

Optimizing the Survival of hESC-Derived RPE Cells Using Layer-by-Layer in Vivo Self-Assembly

2019 ◽  
Author(s):  
Liyan Ru ◽  
Nan Wu ◽  
Keyu Wei ◽  
Yuxiao Zeng ◽  
Qiyou Li ◽  
...  
Keyword(s):  
Self Assembly ◽  
Layer By Layer ◽  
Rpe Cells

scholarly journals Layer-by-Layer Fabrication of Hydrogel Microsystems for Controlled Drug Delivery From Untethered Microrobots

2021 ◽  
Vol 9 ◽  
Author(s):  
Roberto Bernasconi ◽  
Fabio Pizzetti ◽  
Arianna Rossetti ◽  
Brendan Butler ◽  
Marinella Levi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Smart Materials ◽  
Self Assembly ◽  
Low Cost ◽  
Active Material ◽  
Burst Release ◽  
Layer By Layer ◽  
Poor Control ◽  
Major Interest

Targeted drug delivery from untethered microrobots is a topic of major interest in current biomedical research. The possibility to load smart materials able to administer active principles on remotely in vivo guidable microdevices constitutes one of the most attractive opportunities to overcome the drawbacks of classical untargeted delivery methodologies. Hydrogels, in particular, are ideal candidates as drug-carrying materials due to their biocompatibility, low cost, and ease of manufacturing. On the other hand, these polymers suffer from poor control over release rate and overall released amount. Starting from these premises, the present article demonstrates the possibility to tune the release of hydrogels applied on magnetically steerable microrobots by fabricating microsystems via layer-by-layer self-assembly. By doing this, the diffusion of chemicals from the hydrogel layers to the external environment can be optimized and the phenomenon of burst release can be strongly limited. The microrobotic platforms employed to transport the hydrogel active material are fabricated by employing 3D printing in combination with wet metallization and present a gold layer on their surface to enhance biocompatibility. The maneuverability of microdevices coated with both thin and thick multilayers is investigated, individuating optimized parameters for efficient actuation.

Fabrication of Graphene Thin Films Based on Layer-by-Layer Self-Assembly of Functionalized Graphene Nanosheets

2011 ◽  
Vol 3 (2) ◽  
pp. 360-368 ◽  
Author(s):  
Je Seob Park ◽  
Sung Min Cho ◽  
Woo-Jae Kim ◽  
Juhyun Park ◽  
Pil J. Yoo
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Graphene Nanosheets ◽  
Layer By Layer ◽  
Functionalized Graphene

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.

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