Biochar from invasive weed shields rice from toxic nanoplastics and heavy metals

Biochar Editorial Office, Shenyang Agricultural University

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Mitigating combined internalized toxicity of nanoplastics and cadmium in rice through metabolic and biochemical regulations under supply of biochar biofilters derived from Mikania Micrantha

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Credit: Muhammad Shoaib Rana, Rongjie Ren, Muhammad Imran, Yousif Abdelrahman Yousif Abdellah, Hongyu Chen, Shiwen Deng, Jiaxin Li, Jiayu Lin & Ruilong Wang

A team of scientists has found that biochar made from an aggressive invasive plant can protect rice from two modern pollutants that threaten global food security: nanoplastics and cadmium. The study, published in Biochar, reveals how biochar biofilters derived from Mikania micrantha, an invasive vine spreading across Asia, can reduce the combined toxicity of these contaminants by regulating plant metabolism and strengthening rice’s natural defense systems.

Nanoplastics, the tiny fragments of degraded plastics, and cadmium, a persistent heavy metal, frequently coexist in agricultural soils and water. Their combined effects are more harmful than either pollutant alone, disrupting photosynthesis, root growth, and cellular structures in crops. In the new research, rice plants exposed to both pollutants suffered a 16 percent loss in biomass. However, when grown with the Mikania biochar biofilter, biomass increased by more than 80 percent, and chlorophyll and protein levels were significantly restored.

Microscopic imaging showed that nanoplastics were able to penetrate rice roots under cadmium stress, acting as carriers that transported the metal deep into plant tissues. The biochar biofilter formed a physical and chemical barrier, trapping the pollutants and reducing their movement within the plant. The biochar also enhanced the rice’s antioxidant activity and gene expression related to stress defense, helping maintain healthier root and leaf cell structures.

Further biochemical and metabolomic analyses revealed that biochar-treated plants had better nutrient balance and more stable energy cycles, including improved nitrogen transport and tricarboxylic acid (TCA) pathways. In contrast, nanoplastics interfered with hormone signaling and ATP-binding transporters, intensifying cadmium uptake and toxicity.

The findings point to an innovative, sustainable strategy for mitigating pollution in farmlands. Using an invasive weed to produce biochar not only converts ecological waste into a useful soil amendment but also offers a low-cost solution for protecting crops from emerging contaminants. The researchers say the dual benefit, controlling an invasive species while improving soil and plant health, could be valuable for cleaner and safer food production systems.

The study underscores the potential of biochar biofilters as a green technology to combat the intertwined challenges of plastic pollution, heavy metal contamination, and invasive plant management in agriculture.

 

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Journal Reference: Rana, M.S., Ren, R., Imran, M. et al. Mitigating combined internalized toxicity of nanoplastics and cadmium in rice through metabolic and biochemical regulations under supply of biochar biofilters derived from Mikania Micrantha. Biochar 7, 98 (2025). https://doi.org/10.1007/s42773-025-00488-6  

 

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About Biochar

Biochar is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

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Journal

Biochar

DOI

10.1007/s42773-025-00488-6 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Mitigating combined internalized toxicity of nanoplastics and cadmium in rice through metabolic and biochemical regulations under supply of biochar biofilters derived from Mikania Micrantha

 

Soil bacteria and minerals form a natural “battery” that breaks down antibiotics in the dark

Discovery reveals how microbes can store sunlight energy to clean polluted soils and water even without light

Biochar Editorial Office, Shenyang Agricultural University

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A bio-photovoltage soil-microbe battery for antibiotic degradation in the dark

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Credit: Shunling Li, Ye Chen, Min Wu, Peng Zhang, Peng Cui, Wenyan Duan, Bo Pan, & Baoshan Xing

Researchers have unveiled a surprising new way that soil microbes can use sunlight energy — even after the lights go out. A team from Kunming University of Science and Technology and the University of Massachusetts Amherst has developed a “bio-photovoltage soil-microbe battery” that can capture, store, and release solar energy to power the breakdown of antibiotic pollutants in the dark.

The study, published in Environmental and Biogeochemical Processes, shows that common soil bacteria known as Bacillus megaterium can partner with iron minerals to form a living biofilm that behaves like a rechargeable geochemical capacitor. When exposed to light, the iron-bacteria film absorbs photons and stores the resulting electrons. Later, in the absence of light, it releases these stored charges to trigger chemical reactions that degrade antibiotics such as tetracycline and chloramphenicol.

“Our findings reveal that soil microorganisms and minerals can together function like tiny natural batteries,” said co-corresponding author Professor Bo Pan of Kunming University of Science and Technology. “This system can capture sunlight during the day and use that energy at night to remove pollutants.”

In laboratory experiments, the Fe₂O₃–B. megaterium composite generated a total accumulated charge of 8.06 microcoulombs per square centimeter during light–dark cycles. After one hour of light exposure, the system degraded up to 22 percent of antibiotics in complete darkness, a performance up to 67 percent higher than with shorter light exposure.

The mechanism relies on the cycling of iron between its Fe(II) and Fe(III) forms, aided by bacterial metabolism. This redox relay enables electron storage and gradual release, creating a stable power source for dark-phase reactions. The team’s electrochemical analyses confirmed that this mineral–microbe interface enhances charge transfer and reduces energy losses, forming a biological pseudocapacitor.

“This discovery opens a new window into how solar energy can drive biogeochemical processes even below the soil surface where sunlight cannot reach,” said Professor Baoshan Xing of the University of Massachusetts Amherst, a co-corresponding author. “It also suggests an environmentally sustainable way to remediate contaminated soils and groundwater.”

The researchers believe that similar mineral–microbe systems may play a hidden but vital role in natural energy cycles and pollution control across ecosystems.

 

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Journal reference: Li S, Chen Y, Wu M, Zhang P, Cui P, et al. 2025. A bio-photovoltage soil-microbe battery for antibiotic degradation in the dark. Environmental and Biogeochemical Processes 1: e004  https://www.maxapress.com/article/doi/10.48130/ebp-0025-0006  

 

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About the Journal:

Environmental and Biogeochemical Processes is a multidisciplinary platform for communicating advances in fundamental and applied research on the interactions and processes involving the cycling of elements and compounds between the biological, geological, and chemical components of the environment. 

Follow us on Facebook, X, and Bluesky. 

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DOI

10.48130/ebp-0025-0006 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

A bio-photovoltage soil-microbe battery for antibiotic degradation in the dark

 

Widely prescribed opioid painkiller tramadol not that effective for easing chronic pain

While it likely increases the risk of serious side effects, including heart disease; Potential harms probably outweigh benefits, and use should be minimised, say researchers

BMJ Group

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The strong opioid painkiller, tramadol, is not that effective at easing chronic pain for which it’s widely prescribed, finds a pooled data analysis of the available research, published online in BMJ Evidence Based Medicine.

 

And it likely increases the risk of serious side effects, including heart disease, the findings indicate, prompting the researchers to conclude that the potential harms of tramadol probably outweigh its benefits, and that its use should be minimised.

 

Tramadol is a dual action opioid widely prescribed for the treatment of moderate to severe acute and chronic pain. As such, it’s recommended in several medical guidelines for pain management, note the researchers.

 

Its use has surged in recent years, and it’s now among the most commonly prescribed opioids in the US, possibly because of its perceived lower risk of side effects and the widespread belief that it is safer and less addictive than other short-acting opioids, they add.

 

Although tramadol has been included in previous systematic reviews, none has provided a comprehensive assessment of tramadol’s efficacy and safety in a range of chronic pain conditions, they say.

 

In a bid to plug this knowledge gap, the researchers scoured research databases for randomised clinical trials published up to February 2025 that compared tramadol with placebo (dummy treatment) for patients with chronic pain, including cancer pain. 

 

Nineteen clinical trials involving 6506 participants with chronic pain were eligible for inclusion in the analysis. Five looked at the impact of tramadol on neuropathic pain; nine focused on osteoarthritis; four looked at chronic low back pain; and one focused on fibromyalgia.

 

The average age of the trial participants was 58, but ranged from 47 to 69. Tablets were the primary formulation used; only one trial included topical cream. Length of treatment ranged from 2 to 16 weeks while length of follow up ranged from 3 to 15 weeks.

 

Pooled data analysis of the trial results showed that while tramadol eased pain, the effect was small and below what would be considered clinically effective. 

 

Eight of the trials reported on the proportion of serious side effects arising after treatment during follow up periods of between 7 and 16 weeks.

 

Statistical analysis of these trials results indicated a doubling in the risk of harms associated with tramadol compared with placebo, mainly driven by a higher proportion of ‘cardiac events,’ such as chest pain, coronary artery disease, and congestive heart failure. 

 

Use of tramadol was also associated with a heightened risk of some cancers, although the follow up period was short, making this finding “questionable,” say the researchers. 

 

Pooled data analysis of all the trial results indicated that tramadol treatment was associated with a heightened risk of several milder side effects, including nausea, dizziness, constipation, and sleepiness.

 

The researchers acknowledge that the outcome results were at high risk of bias, but this increases the likelihood that the findings overestimate the beneficial effects and underestimate the harmful effects of tramadol, they suggest.

 

They point out: “Approximately 60 million individuals worldwide experience the addictive effects of opioids. In 2019, drug use was responsible for approximately 600,000 deaths, with nearly 80% of these fatalities associated with opioids and approximately 25% resulting from opioid overdose.

 

“In the United States, the number of opioid-related overdose deaths increased from 49,860 in 2019 to 81,806 in 2022. Given these trends and the present findings, the use of tramadol and other opioids should be minimised to the greatest extent possible.”

They conclude: “Tramadol may have a slight effect on reducing chronic pain (low certainty of evidence) while likely increasing the risk of both serious (moderate certainty of evidence) and non- serious adverse events (very low certainty of evidence). The potential harms associated with tramadol use for pain management likely outweigh its limited benefits.”

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Journal

BMJ Evidence-Based Medicine

DOI

10.1136/bmjebm-2025-114101 

Method of Research

Systematic review

Subject of Research

People

Article Title

Tramadol versus placebo for chronic pain: a systematic review with meta- analysis and trial sequential analysis

Article Publication Date

7-Oct-2025

 

Study highlights risks of Caesarean births to future pregnancies

University College London

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Women who have Caesarean births at an advanced stage of labour are about eight times more likely to develop scars in the womb which are known to increase the likelihood of premature births in future pregnancies, UCL researchers have found.

The study, published in the American Journal of Obstetrics & Gynecology, looked at how the stage of labour when the operation is performed affects where the scar forms and how well it heals. More than 40 per cent of all births in high-income countries including England are now by Caesarean.

As labour progresses, the baby moves further down the woman’s womb towards the vagina. In preparation for giving birth, the woman’s cervix – the opening of the womb – opens or ‘dilates’ up to 10 centimetres.

In some cases, doctors may need to intervene and perform a Caesarean procedure for safety reasons. It is a major operation and leaves a scar in the womb.

An earlier study by the same team of UCL researchers found that when this internal scar was close to the cervix, the risk of the woman having a preterm birth (before 37 weeks) in future pregnancies was significantly increased.

In their new study, they wanted to better understand the factors that influence where in the womb these scars are located by scanning women after a Caesarean birth.

They found that women who had a Caesarean at an advanced stage of labour (when the cervix was almost fully (around 8cm) or completely open) were about eight times more likely to have scars that formed within or near the cervix.  In addition, a low position of the baby in the womb increased the chance of a low scar.

The researchers also found that scars lower down the womb healed less well than those higher up the womb.

They say their findings will help better plan follow-up care for women in future and ways for them to avoid preterm births with future pregnancies. The results should also allow doctors to explore ways to improve surgical techniques to reduce risks in the future, they add.

They are calling for more research into the impact of Caesarean scars on gynaecologic symptoms and future pregnancies and to help develop techniques to improve Caesarean-scar healing.

Lead author Dr Maria Ivan (UCL EGA Institute for Women’s Health) said: “We knew that having a Caesarean birth can damage the cervix. Our study is the first to look at where that damage in the womb is depending on how advanced the labour is when the operation takes place.

“Our findings have significant implications for women who have a Caesarean late in their labour and want to have more children.

“This is particularly relevant given the huge increase in the number of women who are having Caesarean births over the last decade.

“These fresh insights can help shape the future care for women having advanced labour Caesarean births, helping doctors better prepare women for giving birth and hopefully also leading to improved surgical techniques which reduce the risk of future complications that Caesarean delivery scars can cause.”

Ninety-three women who had a Caesarean delivery during active labour (defined as the cervix being at least four centimetres dilated) took part in the study.

The researchers examined them using transvaginal ultrasound between four and 12 months after birth to see if the Caesarean operation had left a scar and if so, where it was in the womb.

Almost all of the 93 women – 90 – were found to have a visible internal scar.

The researchers found that for each one-centimetre increase in cervical dilatation during labour, the scar was positioned 0.88mm lower down the womb and closer to the cervix.

Fifty-two of the women’s scars (57.8 per cent) were in the higher part of the womb, with the scars in the rest of the women located either close to the cervix (19 women or 21.1 per cent) or within it (also 19 women or 21.1per cent).

From this, the researchers worked out that having an advanced labour Caesarean birth was associated with an eightfold higher risk of the scar being located near or within the cervix compared to Caesarean births at an earlier stage of labour.

The researchers also looked at the impact the position of the scar had on how well it healed.

Indicators of impaired scar healing included the presence of a scar “niche” – a gap or defect in the wall of the womb at least two millimetres deep. These niches form a pouch where blood can accumulate and may be associated with infertility, irregular menstrual bleeding or complications in future pregnancies.

Based on these indicators, they found that scars which formed close to or within the cervix did not heal as well as scars higher up the womb, posing a greater risk of complications in future pregnancies.

Co-author Professor Anna David, EGA Institute for Women’s Health,
National Institute for Health Research University College London Hospitals Biomedical Research Centre and Deputy Director of charity Tommy’s National Centre for Preterm Birth Research, said: “Caesarean birth in advanced labour is known to be linked with preterm birth. Our findings highlight the importance of healing of the Caesarean scar in the womb and that the stage of labour and low position of the baby can impact how this happens.”

Dr Jyotsna Vohra, Director of Research, Programmes and Impact at Tommy’s, the pregnancy and baby charity, said: “Unplanned Caesarean births can be very stressful, especially when carried out in an emergency to make sure baby arrives safely. Women who have experienced this may already be feeling anxious going into their next pregnancy, and to be then told they’re at increased risk of giving birth early will only add to the anxiety.

“This new research paves the way for better prediction and prevention of preterm birth following a previous Caesarean birth. We’re working closely with healthcare professionals to make sure this research breakthrough translates to improvements in care for women and birthing people whose babies are most at risk of being born too soon.”

The number of women having Caesarean births has risen sharply in England in recent years to 42% (225,762, of which 99,783 were elective and 125,979 registered as emergency Caesareans) of all deliveries in 2023/24 compared with 26% (166,081 deliveries) in 2013/14. ¹

Ends

 

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Journal

American Journal of Obstetrics and Gynecology

DOI

10.1016/j.ajog.2025.09.013 

Method of Research

Observational study

Subject of Research

People

Article Title

Postnatal healing of Caesarean scar: an ultrasound study

Article Publication Date

8-Oct-2025