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 Improving cell survival and engraftment in vivo via layer-by-layer nanocoating of hESC-derived RPE cells

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liyan Ru ◽  
Nan Wu ◽  
Keyu Wei ◽  
Yuxiao Zeng ◽  
Qiyou Li ◽  
...  
Keyword(s):  
Cell Survival ◽  
Retinal Pigment ◽  
Embryonic Stem ◽  
Subretinal Space ◽  
Functional Assay ◽  
Layer By Layer ◽  
Rpe Cells ◽  
Cell Transplants ◽  
Rcs Rats

Abstract Background Human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cell transplants have served as a cell therapy for treating retinal degenerative diseases. However, how to optimize the survival and engraftment of hESC-RPE cells is a great challenge. Methods Here, we report hESC-RPE cells that are embedded with polyelectrolytes gelatin and alginate by layer-by-layer (LbL) self-assembly technique, based on the opposite charge of alternate layers. Cells were assessed for cell survival, immunogenicity, and function in vitro and in vivo. Results This strategy obviously decreased the immunogenicity of hESC-RPE cells without affecting its activity. LbL-RPE cell transplants into the subretinal space of Royal College of Surgeons (RCS) rats optimized cell engraftment and decreased immunogenicity compared to untreated RPE cell transplants (immunosuppression was not used during the 21-week study). Visual-functional assay with electroretinogram recordings (ERGs) also showed higher B wave amplitudes in RCS rats with LbL-RPE cell transplants. Conclusions We demonstrate that transplanted LbL-RPE cells have better viability and grafting efficiency, optimized immunogenicity, and visual function. Therefore, LbL engineering is a promising method to increase the efficacy of hESC-RPE cell transplantation.

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.

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.

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.

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