Tag Archives: USDA

Biochemical fate of nanoemulsion-based food delivery systems in the gastrointestinal tract

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This is a story about nutraceuticals or, more specifically, about nanotechnology and food according to a Jan. 20, 2014 news item on Azonano,

Food scientist Hang Xiao of the University of Massachusetts Amherst recently received a four-year, $491,220 grant to study the biochemical fate of nanoemulsion-based food delivery systems in the gastrointestinal (GI) tract, hoping to re-shape them and enhance the absorption of beneficial food components encapsulated in delivery systems.

Food biochemists like Xiao believe that if taken up in appropriate amounts and forms, certain food components known as nutraceuticals might benefit human health by providing anti-inflammatory or anti-cancer effects. Nutraceuticals include flavonoids and carotenoids in fruits and vegetables, for example.

This project, supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture, will focus on manipulating the structure and composition of nano-emulsion delivery systems to modify the fate of encapsulated nutraceuticals in the GI tract to enhance their bioavailability.

A Jan. 17, 2014 news release on EurekAlert, which originated the news item, explains further,

“In the last decade, knowledge has been advancing about how to effectively deliver beneficial components in food. This research will allow us to direct the assembly of nano-emulsion droplets to create characteristics that will dictate how they are digested and absorbed,” Xiao explains. “This would be a model for nutraceutical delivery in a wide range of food products. Someday prepared foods may help lower our risk of cancer, for example.”

Specifically, using both cell culture and animal models, Xiao and colleagues will design lipid nanoparticles at three stages: From nano-emulsion droplets containing nutraceuticals, to mixed micelles and finally to chylomicrons. To start this process, digestion physiochemically disassembles nano-emulsion droplets. The resulting chemical components are then assembled into mixed micelles in the small intestine, where epithelial cells called enterocytes take them up. There they are reassembled into chylomicrons and absorbed into blood circulation through the lymph system.

The scientists want to influence the size and composition of chylomicrons, because these characteristics dictate the fate of nutraceuticals encapsulated in the chylomicrons. Certain sizes and compositions are better able to deliver nutraceuticals to the lymph system, which protects nutraceuticals from being cleared by the liver. This will enhance bioavailability of flavonoids and other beneficial compounds to the body, potentially offering health benefits.

“We’re basically utilizing what already happens in our bodies all the time, but introducing food-grade nano-emulsion systems that can influence the nature of mixed micelles as well as chylomicrons,” says Xiao. “It’s safe, it’s all digested and simply delivers beneficial food components to a greater extent than if the system was left alone.”

Given that this falls under my nanotechnology and food classification, I was reminded of a recent panel discussion on the topic held by the UK’s Guardian newspaper, from my Oct. 29, 2013 posting,

There’s no indication as to what the 25 audience members thought about the session although Hilary Sutcliffe of Matter was quoted,

Audience member Hilary Sutcliffe, director of the Matter think tank on responsible innovation, was keen to emphasise the limits of nanotechnology in food. “If we’re really lucky, we might get nanosalt and a couple of nano-encapsulated vitamins that go in products,” she told the panel, describing her disappointment in the progress of nanotechnology in food to date.

Sutcliffe explained that these limited applications are expensive and not that useful: manufacturers would rather just reduce salt content than pay for nanosalt, and vitamins and flavourings do not need to be nano-encapsulated because they can be added to foods at the microscale, rather than at the nano-level, which is one thousand times smaller.

She also suggested that, so far, the possible uses of nanotechnology have only been in Western diets and that people should be realistic about its use for tackling the impending global food crisis. “Nothing about nanotechnology is in relation to anything except Western, expensive foods that are slightly gratuitous and not particularly necessary,” she said, before adding that it is not currently helping to feed the world. “If you are going to talk about feeding the world, be brave, take on GM, let’s have that discussion.”

I was not able to find notice of any US public engagement sessions on the topic of ‘nano and food’. If you know of any such sessions, please do share in the comments section.

Development of US plant to produce cellulosic nanomaterials announced again or is this a new one?

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There’s a new announcement from the Secretary of the US Department of Agriculture (USDA) about building a commercial production plant in Wisconsin for producing cellulosic nanomaterials that greatly resembles an earlier announcement in 2012. Let’s start with the new announcement, from the Dec. 11, 2013 USDA press release (h/t AgriPulse Dec. 11, 2013 news item),

U.S. Department of Agriculture (USDA) Secretary Tom Vilsack today announced a public-private partnership to rapidly advance the development of the first U.S. commercial facility producing cellulosic nanomaterial, a wood fiber broken down to the nanoscale. The partnership is between the U.S. Endowment for Forestry and Communities (Endowment) and the U.S. Forest Service.

“We believe in the potential of wood- based nanotechnology to strengthen rural America by creating sustainable jobs and adding timber value while also creating conservation opportunities in working forests,” said Vilsack. “This public- private partnership will develop high-tech outputs from the forest products sector, and promote the invention of renewable products that have substantial environmental benefits.”

…

The three-year partnership will promote cellulosic nanomaterial as a commercially viable enterprise by building on work done by the Forest Products Laboratory in Madison, Wis. The partnership seeks to overcome technical barriers to large- scale wood-based nanotechnology processing, while filling gaps in the science and technology that are needed for commercialization. Initial funding comes from the Endowment and the Forest Service. The partnership is currently seeking additional public and private sector funding.

…

Together with partners, this new venture will:

  • Emphasize the potential of wood- based nanotechnology for the economy and the environment.
  • Overcome technical barriers to commercialization of wood- based nanotechnology.
  • Demonstrate commitment to creating high paying jobs in rural America through value- added manufacturing and high value products.
  • Showcase the commitment of USDA and the Forest Service to innovation.

The previous announcement which I covered in my July 27, 2012 posting has some similarities, although they were announcing the expected construction of a pilot plant for a specific forest-derived cellulosic nanomaterial,,

According to the July 25, 2012 article by Rick Barrett originally published by Milwaukee Journal Sentinel McClatchy-Tribune Information Services) on the equities.com website,

The U.S. Forest Products Laboratory, in Madison, says it’s opening a $1.7 million pilot plant that will support an emerging market for wood products derived from nanotechnology.

…The pilot plant will supply nanocrystals to companies and universities that want to make materials from them or conduct their own experiments. For now, at least, it will employ just one person.

…

But while the Forest Products Laboratory wants to foster the technology, it doesn’t want to compete with businesses interested in producing the materials.

“We are part of the federal government, so we cannot compete against commercial companies. So if someone comes in and starts making these materials on a commercial level, we will have to get out of it,” Rudie said. That’s why, he added, the program has bought only equipment it can use for other purposes.

…

At a guess I’d say plans were changed (to my knowledge there’ve been no announcements about the opening of a pilot plant) and they decided that a commercial plant in a private/public partnership would be the way to go. I notice they’re very careful to use the term cellulosic nanomaterials, which suggests they will be producing not just the crystals mentioned in the 2012 story but fibrils and more.

On the Canadian side of things,, Alberta gave its pilot cellulose nanocrystal (CNC, aka, nanocrystalline cellulose [NCC]) plant a soft launch in Sept. 2013, as per my Nov. 19, 2013 posting,  and Quebec’s CelluForce plant (a  Domtar/FPInnovations partnership [private/public]) has a stockpile of the crystals and is, to my knowledge (my Oct. 3, 2013 posting), is not producing any additional material.

 

Industrial Biotechnology highlights nanotechnology applied to food and agriculture in the US

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The Dec. 2012 issue of Industrial Biotechnology featured a special research section highlighting innovative uses of nanotechnology in agriculture and food in the US. The Jan. 28, 2013 news release on EurekAlert provides more detail,

The U.S. Department of Agriculture (USDA) invests nearly $10 million a year to support about 250 nanoscale science and engineering projects that could lead to revolutionary advances in agriculture and food systems. …

In their introductory article, “Overview: Nanoscale Science and Engineering for Agriculture and Food Systems,” Co-Guest Editors Norman Scott, PhD, Professor, Cornell University (Ithaca, NY) and Hongda Chen, PhD, National Program Leader, National Institute of Food and Agriculture, USDA (Washington, DC), describe the promising early advances nanotechnology is enabling all along the food supply chain, from production through consumption, and especially in the area of food safety.

This special issue of IB [Industrial Biotechnology] includes the review article “Bioactivity and Biomodification of Ag, ZnO, and CuO Nanoparticles with Relevance to Plant Performance in Agriculture” by Anne Anderson and coauthors, Utah State University, Logan, in which they discuss the environmental factors that affect the biological activity and potential agricultural utility of nanoparticle. In the original research article “Effect of Silver Nanoparticles on Soil Denitrification Kinetics” Allison Rick VandeVoort and Yuji Arai, Clemson University (South Carolina), describe the effects of three different silver nanoparticles on native bacteria-mediated soil denitrification.

The short communication “Soft Lithography-Based Fabrication of Biopolymer Microparticles for Nutrient Microencapsulation” by Natalia Higuita-Castro, et al., The Ohio State University and Abbott Nutrition Products Division, Columbus, OH, describes a high-throughput microfabrication method to encapsulate nutrients that can enhance food nutritional value and appearance. Dan Luo and colleagues, Cornell University, Ithaca, NY, present a promising microfluidic-based scale-up method for cell-free protein production in the methods article “Cell-Free Protein Expression from DNA-Based Hydrogel (P-Gel) Droplets for Scale-Up Production.”

“The rapid expansion in nanoscale science and technology in our community with new insights and methods in biomolecular and cellular processing will spur industrial biotechnology innovation in a number of important sectors,” says Larry Walker, PhD, Co-Editor-in-Chief and Professor, Biological & Environmental Engineering, Cornell University, Ithaca, NY.

These articles are open access although I don’t believe that the journal is necessarily open access. Before I explain that further, here’s a bit more about the editors and the publisher,

About the Journal

Industrial Biotechnology, led by Co-Editors-in-Chief Larry Walker, PhD, and Glenn Nedwin, PhD, MBA, is an authoritative journal focused on biobased industrial and environmental products and processes, published bimonthly in print and online. The Journal reports on the science, business, and policy developments of the emerging global bioeconomy, including biobased production of energy and fuels, chemicals, materials, and consumer goods. The articles published include critically reviewed original research in all related sciences (biology, biochemistry, chemical and process engineering, agriculture), in addition to expert commentary on current policy, funding, markets, business, legal issues, and science trends. Industrial Biotechnology offers the premier forum bridging basic research and R&D with later-stage commercialization for sustainable biobased industrial and environmental applications.

About the Publisher

Mary Ann Liebert, Inc., publishers is a privately held, fully integrated media company known for establishing authoritative medical and biomedical peer-reviewed journals, including Metabolic Syndrome and Related Disorders, Population Health Management, Diabetes Technology & Therapeutics, and Journal of Women’s Health. Its biotechnology trade magazine, Genetic Engineering & Biotechnology News (GEN), was the first in its field and is today the industry’s most widely read publication worldwide. A complete list of the firm’s 70 journals, newsmagazines, and books is available on the Mary Ann Liebert, Inc., publishers website at http://www.liebertpub.com.

The publisher, Mary Ann Liebert, offers an open access option to authors and research funders, which means that for a fee, an article will be freely available online but (I strongly suspect) not all the articles in a journal issue are necessarily published under an open access agreement. In contrast, if it’s an article in a Wiley or Elsevier journal, you can be pretty much guaranteed that the online article is behind a paywall.

Meat fresh off the printer

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Modern Meadow Inc. promises to print meat on a 3-D printer at some time in the future but first expects to be printing leather (calfskin) by the end of this year (2012). Anna Kamenetz  in her Aug. 15, 2012 (?) article for Fast Company’s Co.Exist website notes,

… Modern Meadow [MM] co-founder and CEO Andras Forgacs, explains, this new venture is, ahem, a natural outgrowth of that one [a company called Organovo, a startup specializing in 3-D printed, bioengineered organs founded by Andras’ father, Gabor Forgacs who’s co-founded MM with Andras]. “The idea struck us that if we can make medical-grade tissues that are good enough for drug companies, good enough for patients, then certainly we can find other applications for tissue engineering.” Forgacs does seem to understand how terrifying that sounds, which is why his startup has been relatively press-shy until the announcement this morning, and also why they’re starting with wearable, not edible, products. Still, he argues that cell culturing for food is as old as, well, culture itself:

…

“Whether you’re brewing beer or making yogurt, you’re really doing cell culture,” he [Andras Forgacs] says. In this case, though, the process involves biopsying a living animal (a relatively harmless procedure), isolating the desired cells, growing large numbers of them, and preparing them into cell aggregates–spheres of tens of thousands of cells. These aggregates can then become the raw material for more industrial processes. In the case of complete organs, that process is something like 3-D printing. For calfskin–the product that Modern Meadow intends to turn out by the end of the year–it would resemble something more like regular printing or weaving. The end result will be a hairless, pre-tanned, soft, smooth, chemical- and waste-free material in any color or pattern imaginable …

It’s not easy to find information about this company (they don’t seem to have a website) and, I gather from elsewhere in Kamenetz’s article, they’ve been media shy until now.

The US Dept. of Agriculture (USDA)  provides some information about a small business grant they gave to Modern Meadow for the 2012 fiscal year. From the Modern Meadow page on the USDA Research, Education & Economics Information System website, here are the project goals,

The objective of this proposal is to construct muscle tissues by a novel and versatile tissue engineering technology and to assess their texture and composition for use as minced meat. The patented “print-based” technology has several distinguishing features. It is scaffold-free – it does not rely on any artificial material to form the desired structure. The process to build a tissue construct utilizes the automated deposition of convenient multicellular units, suitable for rapid prototyping and high-throughput production. The method has solid scientific underpinning based on tissue self-assembly processes akin to those evident in early morphogenesis (i.e. tissue fusion, engulfment and cell sorting). The ultimate product that will be developed based on the proposed studies is an animal muscle strip that can be used as minced meat for the preparation of sausages, patties and nuggets. The two aims that will be pursued in this Phase I application are 1) to fabricate 3D cellular sheets composed of porcine cells and 2) to mature the cellular sheets into muscle tissue and measure its meat characteristics. The related technical objectives are 1) to determine the optimal cellular composition (type and ratio of muscle cells, fibroblasts and adipocytes) to produce “easy-to-handle” cellular sheets and 2) to find the most efficient stimulation method (mechanical, electrical or a combination of both) to achieve muscle formation with similar mechanical and biochemical properties to meat. The successful completion of the proposed project will provide the optimal parameters and conditions for engineering strips of mammalian muscle tissue ((2 x 1 x 0.5) cm3) with appropriate mechanical and biochemical properties to be used as minced lean meat. The building of larger pieces, that may need to be perfused and engineered around bio-printed blood vessels, would be carried out in Phase II.

If you’d told me about ‘vat’ or ‘printed’ meat five years ago I would have been horrified and suspicious. I’m somewhat less horrified today but still suspicious or perhaps I should call it, cautious.

Cotton and nanotechnology at the US Dept. of Agriculture

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The April 2012 item by Jan Suszkiw of the US Dept. of Agriculture (on the Western Farm Press website) seemed strangely familiar as it focused on research into flame-retardant cotton. From the Suszkiw article,

In one ongoing project, the researchers have teamed with Texas A&M University scientists to evaluate a first-of-its-kind, environmentally friendly flame-retardant for cotton apparel and durable goods. Halogenated flame retardants have been among the most widely used chemical treatments, but there’s been a push to find alternatives that are more benign and that won’t cause treated fabric to stiffen, according to Condon [Brian Condon, Agricultural Research Service [ARS]).

I mentioned the research work in the context of a 2011 meeting of the American Chemical Society in my Sept. 6, 2011 posting (scroll down about 3/4 of the way) except the focus was on the Texas A&M University in College Station research team who had yet to collaborate with Condon’s team at the ARS,

In responding to the need for more environmentally friendly flame retardants, Grunlan’s [Jaime C. Grunlan] team turned to a technology termed “intumescence,” long used to fireproof exposed interior steel beams in buildings. At the first lick of a flame, an intumescent coating swells up and expands like beer foam, forming tiny bubbles in a protective barrier that insulates and shields the material below. The researchers are at Texas A&M University in College Station. …

Since the meeting last fall, the two teams (US ARS [Condon] and Texas A&M [Grunlan]) have collaborated to make cotton more flame retardant according to the April 2012 news article (Cotton Gets Nanotech and Biotech Treatment in New Orleans) on the US Dept. of Agriculture, Agricultural Research Service website (Note: I have removed a link),

Condon and CCUR (Cotton Chemistry and Utilization Research Unit) chemist SeChin Chang are collaborating with Texas A&M University (TAMU) scientists to evaluate a first-of-its-kind, environmentally friendly flame retardant for cotton apparel and durable goods.

Halogenated flame retardants have been among the most widely used chemical treatments for cotton. But there’s been a push to find alternatives that are not only more benign, but that also avoid imparting the same stiffness to fabric characteristic of some chemical treatments. For these and other reasons, “the textiles industry would like to move away from using halogenated flame retardants,” says Condon.

Made of water-soluble polymers, nanoscale clay particles, and other “green” ingredients, the ARS-TAMU flame retardant is applied as a nanocoating that reacts to open flame by rapidly forming a swollen, charred surface layer. This process, known as “intumescence,” stops the flame from reaching underlying or adjacent fibers.

A team led by Jaime Grunlan at TAMU’s Department of Mechanical Engineering, in College Station, Texas, originally developed the intumescent nanocoating using a layer-by-layer assembly. In this procedure, alternating layers of positively and negatively charged ingredients, including clay particles 50-100 nanometers wide, are deposited onto the surface of a desired material. The result is a striated nanocoating that, when viewed under a scanning electron or other high-powered microscope, resembles the stacked layers of a brick wall.

Condon’s interest was piqued after listening to Grunlan discuss his team’s research at a recent American Chemical Society meeting, and he approached the TAMU professor about potential benefits to cotton. That conversation, in turn, led to a cooperative research project enabling Condon and Chang to evaluate the nanocoating at CCUR.

Treating cotton for flame resistance isn’t a recent concept, adds Condon, whose lab is part of the ARS Southern Regional Research Center in New Orleans. In fact, some of the most successful early treatments were born of research conducted by Benerito [Ruth Benerito] and colleagues there several decades ago. (See “Cross-Linking Cotton,” Agricultural Research, February 2009, pp. 10-11.) Condon coauthored a 2011 ACS Nano paper on the potential of intumescent coatings together with Chang, Grunlan and his TAMU team, and Alexander Morgan of the University of Dayton Research Institute in Ohio.

Early trials of the nanocoating using standard flame-resistance tests are promising. In one case, 95 percent of treated cotton fabric remained intact after exposure to flame, whereas the untreated fabric used for comparison was completely destroyed

“What we’re investigating now is how well it will perform after repeated launderings of treated fabric,” says Condon. “After all, the coating contains clay, and that’s something detergents are made to remove.”

Even if the coating does eventually wash out and the treated fabric loses its flame resistance, the nanotech approach could still be used to protect textiles and durable goods that aren’t frequently washed, such as upholstery, mattress pads, box spring covers, automotive interiors, and firefighter coats.

This is one of the images that accompany the article,

Cross-section of a cotton fiber with clay nanoparticles attached. (from: http://www.ars.usda.gov/is/AR/archive/apr12/cotton0412.htm)

If you are interested in the work being done by the US Dept. of Agriculture’s Agricultural Research Service on cotton, there’s a lot more than I managed to excerpt.

Nanocellulose at the American Chemical Society’s 243rd annual meeting

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Nanocellulose seems to be one of the major topics at the ACS’s (Americal Chemical Society) 243rd annual meeting themed Chemistry of Life  in San Diego, California, March 25-29, 2012. From the March 25, 2012 news item on Nanowerk,

… almost two dozen reports in the symposium titled, “Cellulose-Based Biomimetic and Biomedical Materials,” that focused on the use of specially processed cellulose in the design and engineering of materials modeled after biological systems. Cellulose consists of long chains of the sugar glucose linked together into a polymer, a natural plastic–like material. Cellulose gives wood its remarkable strength and is the main component of plant stems, leaves and roots. Traditionally, cellulose’s main commercial uses have been in producing paper and textiles –– cotton being a pure form of cellulose. But development of a highly processed form of cellulose, termed nanocellulose, has expanded those applications and sparked intense scientific research. Nanocellulose consists of the fibrils of nanoscale diameters so small that 50,000 would fit across the width of the period at the end of this sentence.

“We are in the middle of a Golden Age, in which a clearer understanding of the forms and functions of cellulose architectures in biological systems is promoting the evolution of advanced materials,” said Harry Brumer, Ph.D., of Michael Smith Laboratories, University of British Columbia, Vancouver. He was a co-organizer of the symposium with J. Vincent Edwards, Ph.D., a research chemist with the Agricultural Research Service, U.S. Department of Agriculture in New Orleans, Louisiana. “This session on cellulose-based biomimetic and biomedical materials is really very timely due to the sustained and growing interest in the use of cellulose, particularly nanoscale cellulose, in biomaterials.”

One of the presenters has a very charming way of describing the nanocellulose product his team is working on (from the news item),

Olli Ikkala, Ph.D., [Aalto University, Finland] described the new buoyant material, engineered to mimic the water strider’s long, thin feet and made from an “aerogel” composed of the tiny nano-fibrils from the cellulose in plants. Aerogels are so light that some of them are denoted as “solid smoke. [emphasis mine]” The nanocellulose aerogels also have remarkable mechanical properties and are flexible.

There were some 20 presentations in this symposium held under the auspices of the ACS annual meeting. Here’s a few of the presentations (some of these folks have been featured on this blog previously), from the news item,

Native cellulose nanofibers: From biomimetic nanocomposites to functionalized gel spun fibers and functional aerogels Olli Ikkala, Professor, PhD, Aalto University, P.O. Box 5100, Espoo, Finland, FIN-02015, Finland , 358-9-470 23154, olli.ikkala@aalto.fi Native cellulose nanofibers and whiskers attract interest even beyond the traditional cellulose community due to their mechanical properties, availability and sustainability. We describe biomimetic nanocomposites with aligned self-assemblies combining nanocellulose with nanoclays, polymers, block copolymer, or graphene, allowing exciting mechanical properties. Functional ductile and even flexible aerogels are presented, combining superhydrophobicity, superoleophobicity, oil-spill absorption, photocatalytics, optically switchable water absorption, sensing, and antimicrobial properties. Finally mechanically excellent fibers are gel-spun and functionalized for electric, magnetic, optical and drug-release properties.

Evaluation of skin tissue repair materials from bacterial cellulose Lina Fu, Miss, Huazhong University of Science & Technology, College of Life Science & Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, China , 86-18971560696, runa0325@gmail.com Bacterial cellulose (BC) has been reported as the materials in the tissue engineering fields, such as skin, bone, vascular and cartilage tissue engineering. Exploitation of the skin substitutes and modern wound dressing materials by using BC has attracted much attention. A skin tissue repair materials based on BC have been biosynthesized by Gluconacetobacter xylinus. The nano-composites of BC and chitosan form a cohesive gel structure, and the cell toxicity of the composite is excellent. Unlike other groups, which showed more inflammatory behavior, the inflammatory cells of the BC group were mainly polymorph-nuclear and showed few lymphocytes. The BC skin tissue repair material has an obviously curative effect in promoting the healing of epithelial tissue and reducing inflammation. With its superior mechanical properties, and the excellent biocompatibility, these skin tissue repair materials based on BC have great promise and potential for wound healing and very high clinical value.

….

New materials from nanocrystalline cellulose Mark MacLachlan [mentioned in my Nov. 18, 2010 posting], University of British Columbia, Department of Chemistry, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada , 604-822-3070, mmaclach@chem.ubc.ca Nanocrystalline cellulose (NCC) is available from the acid-catalyzed degradation of cellulosic materials. NCC is composed of cylindrical crystallites with diameters of ca. 5-10 nm and large aspect ratios. This form of cellulose has intriguing properties, including its ability to form a chiral nematic structure. By using the chiral nematic organization of NCC as a template, we have been able to create highly porous silica films and carbon films with chiral nematic organization.1,2 These materials are iridescent and their structures mimic the shells of jewel beetles. In this paper, I will describe our recent efforts to use NCC to create new materials with interesting optical properties.

Factors influencing chiral nematic pitch and texture of cellulose nanocrystal films Derek G Gray, McGill University, Department of Chemistry, Pulp and Paper Building, 3420 University Street, Montreal, QC, H3A 2A7, Canada , 1-514-398-6182, derek.gray@mcgill.ca Appropriately stabilized cellulose nanocrystal (NCC) suspensions in water form chiral nematic liquid crystalline phases above some critical concentration. In the absence of added electrolye, the chiral nematic pitch of such suspensions is longer than that of visible light. Films prepared by evaporation from the suspensions also often display the characteristic fingerprint patterns characteristic of long-pitch chiral nematic phases, but the pitch values can be shifted into the visible range by adding small quantities of electrolyte to the evaporating suspension. The factors that control the final pitch have been the subject of some confusion. While still not well understood, it is clear that at high nanocrystal concentrations and in solid films, the pitch is not simply a reversible function of nanocrystal concentration. We examine some of the factors that control the pitch and liquid crystal texture during the drying of chiral nematic NCC films.

….

Bioprinting of 3D porous nanocellulose scaffolds for tissue engineering and organ regeneration Paul Gatenholm, Professor, [mentioned in my March 19, 2012 posting] Wallenberg Wood Science Center, Chalmers, Department of Chemical and Biological Engineering, Kemigarden 4, Goteborg, V. Gotaland, SE41296, Sweden , 46317723407, paul.gatenholm@chalmers.se Nanocellulose is a promising biocompatible hydrogel like nano-biomaterial with potential uses in tissue engineering and regenerative medicine. Biomaterial scaffolds for tissue engineering require precise control of porosity, pore size, and pore interconnectivity. Control of scaffold architecture is crucial to promote cell migration, cell attachment, cell proliferation and cell differentiation. 3D macroporous nanocellulose scaffolds, produced by unique biofabrication process using porogens incorporated in the cultivation step, have shown ability to attract smooth muscle cells, endothelial cells, chondrocytes of various origins, urethral cells and osteoprogenitor cells. We have developed bioprinter which is able to produce 3D porous nanocellulose scaffolds with large size and unique architecture. Surface modifications have been applied to enhance cell adhesion and cell differentiation. In this study we have focused on use of 3D porous Nanocellulose scaffolds for stem cell differentiation into osteogenic and chondral lineages.