Tissue scaffolds and heavy
metal removal
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Cheap, effective heavy metal removal
Heavy metals are a serious problem in both domestic and industrial
wastewater. Researchers working jointly in Greece and Russia
believe they may have found a more cost-effective method for
heavy metal removal.
Currently treatment involves a myriad of processes ranging
from precipitation, sedimentation, coagulation to filtration
and biosorption. The current processes have a number of disadvantages,
including the high cost of electro-coagulation and additional
purification processes needed to remove purification agents.
The team used a galvanochemical removal process using an anode
and cathode of suitable, different electrochemical potentials.
They successfully removed 90% of zinc over five hours using
an anode-cathode pair of iron and coke. This process, unlike
electro-coagulation, does not use any electricity and the
anode-cathode has the potential to be recycled, making this
a cheap and effective way to remove heavy metals.
| Removal of zinc from dilute aqueous
solutions by galvanochemical treatment, AI Zouboulis,
CA Prochaska and PM Solozhenkin, Journal of Chemical
Technology and Biotechnology, DOI: 10.1002/jctb.1233
(Available on EarlyView) |
Improved bone tissue scaffolds
Scientists at Tsinghua University in China have been working
on scaffolds for bone tissue engineering. Bone tissue scaffolds
are often required to help repair or replace damaged or diseased
tissues in cases of trauma, congenital and degenerative diseases,
cancer and cosmetics. These scaffolds are made from materials
from a natural source such as collagen. They provide a framework
in which bone tissue cells can reproduce and can then be transplanted
into the patient. As the scaffold is biodegradable it will
be broken down, leaving just the active bone tissue cells
creating new bone.
The researchers reinforced their collagen-based
scaffold with biocompatible chitosan fibres. The fibres improved
the mechanical properties of the structure, increasing the
porosity and providing ideal pore size for cell growth without
altering its degradation rate. A comparison with and without
the fibres demonstrated a 20% increase in cell growth with
the fibres.
| Collagen-based scaffolds reinforced
by chitosan fibres for bone tissue engineering, Xiaoming
Li, Qingling Feng, Yunfeng Jiao and Fuzhai Cui, Polymer
International, DOI: 10.1002/pi.1804 (Available on
EarlyView). |
Filtering blood for toxins
Chinese researchers have been examining methods to remove
bilirubin from blood. Bilirubin is a metabolite produced by
aging red blood cells. It is normally joined to albumin to
decrease its toxicity and is then processed in the liver.
If, due to disease or damage, the liver is unable to remove
bilirubin it can lead to jaundice. This condition, particularly
common in newborn babies, can lead to accumulation of bilirubin
in the brain causing neurological damage.
Attempts have been made to remove bilirubin directly from
patients’ blood before, but have only been successful
in mild cases of hyperbilirubinemia. The researchers prepared
activated nylon membranes with affinity for bilirubin. The
membranes were tested using solutions that mimicked jaundiced
blood. They found that the membranes were able to remove bilirubin
successfully, but only at low feed-through rates, making them
unsuitable for medical use at present.
| Adsorption of bilirubin on poly-L-lysine-containing
nylon membranes: applications in affinity chromatography,
Wei Shi, Fengbao Zhang, Guoliang Zhang, Dongtao Ge, Qiqing
Zhang, Polymer International, DOI: 10.1002/pi.1766
(Available on EarlyView)
|
Novel production of biomaterial
Researchers in Indicinal plant purificationia have produced
a hydrogel that they hope will have medical and health applications.
These hydrogels have a very high capacity for absorbing aqueous
media into their structures giving them good potential in
the medical field. The researchers used polyvinyl alcohol
and combined it with casein to make a biocompatible, non-toxic,
non-carcinogenic material with good elasticity and film forming
properties. The hydrogel could have applications in contact
lens production, wound dressing, artificial implants and drug
delivery.
Current hydrogel production tends to lead to contamination
from toxic precursors and reduced biocompatibility. The Indian
group used freeze-thawing cycles to create a highly elastic
hydrogel with good biocompatibility. This material had none
of the toxic contaminants from more traditional production
methods.
| Preparation and characterization
of spongy cryogels of poly(vinyl alcohol)-casein system:
water sorption and blood compatibility study, Anil
Bajpai, Rajesh Saini, Polymer International, DOI:
10.1002/pi.1773(Available on EarlyView) |
|
