Features | Partner Sites | Information | LinkXpress
Sign In
PZ HTL SA
GLOBETECH PUBLISHING
GLOBETECH PUBLISHING

Methodic Strategy Developed for 3D Tissue Engineering of Viable Organ Implants

By BiotechDaily International staff writers
Posted on 27 Aug 2013
Image: Confocal microscopy images showing the different levels of organization (Photo courtesy of Agency for Science, Technology and Research (A*STAR), Singapore).
Image: Confocal microscopy images showing the different levels of organization (Photo courtesy of Agency for Science, Technology and Research (A*STAR), Singapore).
Researchers in Singapore have developed a simple way to organize cells and their microenvironments in hydrogel fibers. Their novel technology provides a practical template for constructing complicated structures, such as liver and fat tissues.

The investigators published their findings August 19, 2013, in the journal Nature Communications. According to the Institute of Bioengineering and Nanotechnology (IBN; Singapore) executive director Prof. Jackie Y. Ying, “Our tissue engineering approach gives researchers great control and flexibility over the arrangement of individual cell types, making it possible to engineer prevascularized tissue constructs easily. This innovation brings us a step closer toward developing viable tissue or organ replacements.”

IBN team leader and lead research scientist, Dr. Andrew Wan, elaborated, “Critical to the success of an implant is its ability to rapidly integrate with the patient’s circulatory system. This is essential for the survival of cells within the implant, as it would ensure timely access to oxygen and essential nutrients, as well as the removal of metabolic waste products. Integration would also facilitate signaling between the cells and blood vessels, which is important for tissue development.”

Tissues designed with preformed vascular networks are known to foster rapid vascular integration with the host. Generally, prevascularization has been achieved by seeding or encapsulating endothelial cells, which line the interior surfaces of blood vessels, with other cell types. In many of these approaches, the eventual distribution of vessels within a thick structure is based on in vitro cellular infiltration and self-organization of the cell mixture. These are slow processes, frequently leading to a nonuniform network of vessels within the tissue. As vascular self-assembly requires a large concentration of endothelial cells, this technique also greatly restricts the number of other cells that may be co-cultured.

Alternatively, scientists have attempted to direct the distribution of newly formed vessels via three-dimensional (3D) co-patterning of endothelial cells with other cell types in a hydrogel. This approach allows large concentrations of endothelial cells to be placed in specific areas within the tissue, leaving the rest of the construct available for other cell types. The hydrogel also acts as a reservoir of nutrients for the encapsulated cells. However, co-patterning multiple cell types within a hydrogel is not easy. Traditional techniques, such as micromolding and organ printing, are limited by large volumes of cell suspension, slow cell assembly, complicated multistep processes, and costly instruments. These factors also make it difficult to scale up the production of implantable 3D cell-patterned constructs. Up to now, these strategies have not been able to achieve vascularization and mass transport through dense engineered tissues.

To overcome these hurdles, IBN researchers have used interfacial polyelectrolyte complexation (IPC) fiber assembly, a unique cell patterning technology patented by IBN, to generate cell-laden hydrogel fibers under aqueous conditions at room temperature. In contrast to other technology, IBN’s unique technique allows researchers to incorporate different cell types separately into different fibers, and these cell-laden fibers may then be assembled into more complex constructs with hierarchical tissue structures. Furthermore, IBN researchers are able to customize the microenvironment for each cell type for enhanced functionality by integrating the appropriate factors, e.g., proteins, into the fibers. Using IPC fiber assembly, the researchers have engineered an endothelial vessel network, as well as liver tissue constructs and cell-patterned fat, which have successfully integrated with the host circulatory system in a mouse model and produced vascularized tissues.

The IBN researchers are now working on applying and further developing their technology toward engineering functional tissues and clinical applications.

Related Links:
Institute of Bioengineering and Nanotechnology



Channels

Genomics/Proteomics

view channel
Image: The TheraCyte cell encapsulation device (Photo courtesy of TheraCyte, Inc.).

Encapsulated Human-Insulin-Producing Progenitor Cells Cure Diabetes in Mouse Model

A breakthrough system that allows subcutaneous implantation of encapsulated immature pancreatic cells (beta progenitor cells) was shown to produce enough insulin to correct the symptoms of diabetes in a mouse model.... Read more

Drug Discovery

view channel
Image: Chitosan is derived from the shells of shrimp and other sea crustaceans, including Alaskan pink shrimp, pictured here (Photo courtesy of NOAA - [US] National Oceanic and Atmospheric Administration).

Chitosan Treatment Clears the Way for Antibiotics to Eliminate Recurrent Urinary Tract Infections

Recurrent urinary tract infection was successfully resolved in a mouse model by treatment with the exfoliant chitosan followed by a round of antibiotics. Bacterial urinary tract infection (UTI), most... Read more

Biochemistry

view channel

Mitochondrial Cause of Aging Can Be Reversed

Researchers have found a cause of aging in lab animals that can be reversed, possibly providing an avenue for new treatments for age-related diseases including type 2 diabetes, cancer, muscle wasting, and inflammatory diseases. The researchers plan to begin human trials late 2014. The study, which was published December... Read more

Therapeutics

view channel

Cytokine Identified That Causes Mucositis in Cancer Therapy Patients

The action of the cytokine interleukin 1-beta (IL-1beta) has been found to underlie the onset of mucositis, a common, severe side effect of chemotherapy and irradiation of cancer patients. Mucositis occurs as a result of cell death in reaction to chemo- or radiotherapy. The mucosal lining of the mouth becomes thin, may... Read more

Business

view channel

Analytical Sciences Trade Fair Declared a Rousing Success

Organizers of this year's 24th "analytica" biosciences trade fair have reported significant increases in both the number of visitors and exhibitors compared to the 2012 event. The analytica trade fair for laboratory technology, analysis, and biotechnology has been held at the Munich (Germany) Trade Fair Center every... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.