RSC Advances Blog

Printing replacement body parts may sound like something out of a sci-fi novel, but since 3D printing was introduced in the 1980s, scientists have been aspiring to make this a reality. Now, a team from Texas in the US has developed a super tough biomaterial that could be used to print load-bearing body parts such as knee cartilage. 

The Texas team 3D printed a meniscus out of an alginate-containing hydrogel

A severe shortage of donors and biocompatibility issues are just two of the hurdles hindering successful transplants. Printing replacement tissues that function as well as, or better than the original tissue could be a way to side-step these obstacles. 

To read the full article visit Chemistry World.

3D printing of an extremely tough hydrogel
Junhua Wei, Jilong Wang, Siheng Su, Shiren Wang, Jingjing Qiu, Zhenhuan Zhang, Gordon Christopher, Fuda Ning and Weilong Cong �
RSC Adv., 2015,5, 81324-81329
DOI: 10.1039/C5RA16362E, Paper

A lack of clinically available antidotes for general anaesthesia has prompted a team of researchers in China and Canada to explore the potential of a macrocyclic compound for halting anaesthesia in zebrafish. General anaesthetics put patients into reversible comas before surgery, but their effects can linger beyond their usefulness, resulting in neurotoxicity and cardiotoxicity, or in death, so if an equivalent molecule could be developed for humans it could save lives.

Cucurbit[n]urils are macrocycles that can inhibit the bioactivity of certain drugs by complexing and encapsulating them to neutralise their effects. Now, Ruibing Wang and co-workers at the University of Macao, China, and Queen’s University in Kingston, Canada, have shown that cucurbit[7]uril can encapsulate the anaesthetic tricaine within its lipophilic cavity. Tricaine acts as a general anaesthetic in cold-blooded animals and fish; in zebrafish it blocks ion channels within nerve membranes. Cucurbit[7]uril acts as a competitive receptor to remove tricaine from these channels and inhibit its anaesthetic properties. The resulting concentration gradient encourages any remaining tricaine to migrate away from the ion channel junction and into the plasma, to be snapped up by further host macrocycles.

To read the full article visit Chemistry World.

In vivo reversal of general anesthesia by cucurbit[7]uril with zebrafish models
Huanxian Chen, Judy Y. W. Chan, Shengke Li, Jessica J. Liu, Ian W. Wyman, Simon M. Y. Lee, Donal H. Macartney and Ruibing Wang
RSC Adv., 2015,5, 63745-63752
DOI: 10.1039/C5RA09406B

What is pain? It can be described as a feeling. It alerts us to damage, and its onset can help to protect us from hurting ourselves again or further.

According to the T-800 of the Terminator series, pain is data, and there are many scientists out there who would agree; however, it would have been an entirely different film if Arnold Schwarzenegger had threatened people with processing proteomics analyses.

While making robots ‘feel’ pain may seem the stuff of sci-fi movies, Yeri Jeong and co-workers show us in their recent publication in RSC Advances, that it is a very legitimate line of research. If robots can feel pain, it can improve their range of applications, especially in harsh environments as they may engage a protective mode.

The research team, based in Korea and the UK, have created a nanowire array that can detect signals based on pattern analysis and pressure, for example, the sharp point of a pencil would be more painful than the soft end with the eraser. The electromechanical structure used comprising flexible ZnO nanowires can mimic the different deformations of the skin to generate a signal. Once that signal goes above a threshold pressure level, it yields an artificial pain signal based on both pattern analysis and force.

They tested the array with a variety of different objects and pressure levels with an earplug and a pen lid, amongst other objects of torture. The array produced a ‘pain’ signal when stabbed with a sharp object at high force, in a quick response time. Yeri Jeong said ‘I’ll be back’ with more sensors – ok, I made that bit up but they do write that the simple design may find application in various devices and the robot industry.

To find out more, click below to read the full article in RSC Advances.

Psychological tactile sensor structure based on piezoelectric nanowire cell arrays, Yeri Jeong, Minkyung Sim, Jeong Hee Shin, Ji-Woong Choi, Jung Inn Sohn, Seung Nam Cha, Hongsoo Choi, Cheil Moon and Jae Eun Jang, RSC Adv., 2015, 5, 40363-40368 (DOI: 10.1039/C5RA05744B)

Sarah Brown is a guest web-writer for RSC Advances. Sarah hung up her lab coat after finishing her PhD and post-doctorate in nanotechnology for diagnostics and therapeutics and now works in academic publishing. When not trying to explain science through ridiculous analogies, you can often find her crocheting, baking or climbing, but not all at once.

The team compared dinosaur and prehistoric shark teeth with those from great white sharks (Carcharodon carcharias)

New research by scientists in Germany has uncovered a curious difference between present-day shark teeth and those of their prehistoric relatives. Although the tooth structure of extinct sharks, like the giant Megalodon, was remarkably similar to great whites and other modern-day sharks, the material they were made from bore a closer resemblance to dinosaur teeth and hints that this change in composition might be down to a dramatic environmental change.

Most animal teeth contain a layer of hard enamel, a soft dentin middle and inner pulp. Dentin and enamel are usually composed of the mineral hydroxyapatite but modern-day sharks differ; their enamel equivalent uses fluoroapatite.

To read the full article visit Chemistry World.

Dental lessons from past to present: ultrastructure and composition of teeth from plesiosaurs, dinosaurs, extinct and recent sharks
A. Lübke, J. Enax, K. Loza, O. Prymak, P. Gaengler, H.-O. Fabritius, D. Raabe and M. Epple  
RSC Adv., 2015,5, 61612-61622
DOI: 10.1039/C5RA11560D, Paper

At a time when materials are increasingly having dual functions, researchers at the Central Leather Research Institute in India are developing ‘smart leathers’. Now, a team there has established a method for imparting leather with a long-lasting lemongrass scent.

Raghava Rao and colleagues used emulsion polymerisation to encapsulate lemongrass oil because of its speed and scalability. Despite the volatile nature of essential oils, when encapsulated in a biopolymer made from chitosan and acrylic acid, the lemongrass scent persists for up to three years. With an average diameter of 117nm, the nanospheres were uniformly distributed within spaces across the leather matrix, and the resulting hydrophilicity and lipophilicity suggests the oils penetrated into the leather.

The nanospheres diffused into the leather matrix and deposited on the collagen fibres

To read the full article visit Chemistry World.

Development of smart leathers: incorporating scent through infusion of encapsulated lemongrass oil
Punitha Velmurugan, Nishad Fathima Nishter, Geetha Baskar, Aruna Dhathathreyan and Jonnalagadda Raghava Rao  
RSC Adv., 2015,5, 59903-59911
DOI: 10.1039/C5RA05508C, Paper

Let’s talk good bacteria, and I don’t mean the kind in your yoghurt. No, I’m talking the kind in your concrete. Fear not, it is not a new breakfast craze. E. coli-based bioconcrete materials have been around for some time now, imbuing properties that allow cracks in the concrete to heal, improving the strength and durability of this material and also all lovely and green – reducing the overall energy cost and carbon dioxide generated in comparison to conventional processes.

Writing in RSC Advances, Manas Sarkar and co-workers have made the good bacteria even better by taking a gene from a bacterium that survives in hot springs, thriving at around 65 ˚C, amplifying it by PCR and implanting it in E. coli bacteria, engineering a unique strain. The gene in question is a silica leaching gene, which has previously been reported to impart higher compressive strength and durability. They add the gene into E. coli as these bacteria are easy to handle, effective at ambient temperatures and more efficient economically.

Concrete samples with the modified bacteria were shown to be 30% stronger than the control, thought to be in part a result of the protein producing a new silicate phase that fills the matrices of micropores in the material.

So, while you may think it a good idea to slather that crack in your ceiling with some probiotic yoghurt from the fridge – stand fast. The smarter bioconcrete is coming.

To find out more, click below to read the full article in RSC Advances.

Development of an improved E. coli bacterial strain for green and sustainable concrete technology
Manas Sarkar, Nurul Alam, Biswadeep Chaudhuri, Brajadulal Chattopadhyay and Saroj Mandal
RSC Adv., 2015, 5, 32175-32182

Sarah Brown is a guest web-writer for RSC Advances. Sarah hung up her lab coat after finishing her PhD and post-doctorate in nanotechnology for diagnostics and therapeutics and now works in academic publishing. When not trying to explain science through ridiculous analogies, you can often find her crocheting, baking or climbing, but not all at once.

Soil bacteria communities become richer and more diverse on exposure to graphene oxide, new research shows.¹ This unexpected finding, unearthed by scientists in China, highlights that despite graphene oxide’s potential for widespread environmental release, little is known about its ecological impact.

Digging deeper into the environmental impact of nanomaterial contamination © Shutterstock

Graphene oxide’s abundance of surface oxygen-containing groups makes it a useful precursor to the graphene-based materials poised to revolutionise electronics and nanoproduct industries. Soil ecosystems will likely bear the brunt of nanomaterial contamination and while previous studies have looked at graphene oxide’s effect in pure bacterial cultures, soil is a much more complicated medium with diverse microbial communities that demand closer investigation. Now a team led by Xiangang Hu and Qixing Zhou’s of Nankai University has studied the effects of graphene oxide in the soil for 90 days using high-throughput sequencing analysis.

To read the full article visit Chemistry World.

Graphene oxide regulates the bacterial community and exhibits property changes in soil
Junjie Du, Xiangang Hu and Qixing Zhou  
RSC Adv., 2015,5, 27009-27017
DOI: 10.1039/C5RA01045D, Paper