Tag Archives: cancer therapy

Scientists at Indian Institute of Science (IISc) created hybrid nanoparticles made of gold and copper sulfide that can kill cancer cells

It’s been a while since there was a theranostic (diagnosis and therapy combined in one treatment) story here.

Caption: Schematic indicating photo-theranostic potential of TSP-CA Credit: Madhavi Tripathi

A September 11, 2023 news item on phys.org announces the research, Note: A link has been removed,

Scientists at the Indian Institute of Science (IISc) have developed a new approach to potentially detect and kill cancer cells, especially those that form a solid tumor mass. They have created hybrid nanoparticles made of gold and copper sulfide that can kill cancer cells using heat and enable their detection using sound waves, according to a study published in ACS Applied Nano Materials.

A September 11, 2023 Indian Institute of Science (IISC) press release (also on EurekAlert), which originated the news item, provides more detail about the research,

Early detection and treatment are key in the battle against cancer. Copper sulphide nanoparticles have previously received attention for their application in cancer diagnosis, while gold nanoparticles, which can be chemically modified to target cancer cells, have shown anticancer effects. In the current study, the IISc team decided to combine these two into hybrid nanoparticles.  

“These particles have photothermal, oxidative stress, and photoacoustic properties,” says Jaya Prakash, Assistant Professor at the Department of Instrumentation and Applied Physics (IAP), IISc, and one of the corresponding authors of the paper. PhD students Madhavi Tripathi and Swathi Padmanabhan are co-first authors.

When light is shined on these hybrid nanoparticles, they absorb the light and generate heat, which can kill cancer cells. These nanoparticles also produce singlet oxygen atoms that are toxic for the cells. “We want both these mechanisms to kill the cancer cell,” Jaya Prakash explains.  

The researchers say that the nanoparticles can also help diagnose certain cancers. Existing methods such as standalone CT and MRI scans require trained radiology professionals to decipher the images. The photoacoustic property of the nanoparticles allows them to absorb light and generate ultrasound waves, which can be used to detect cancer cells with high contrast once the particles reach them. The ultrasound waves generated from the particles allow for a more accurate image resolution as sound waves scatter less when they pass through tissues compared to light. Scans created from the generated ultrasound waves can also provide better clarity and can be used to measure the oxygen saturation in the tumour, boosting their detection.

“You can integrate this with existing systems of detection or treatment,” says Ashok M Raichur, Professor at the Department of Materials Engineering, and another corresponding author. For example, the nanoparticles can be triggered to produce heat by shining a light on them using an endoscope that is typically used for cancer screening. 

Previously developed nanoparticles have limited applications because of their large size. The IISc team used a novel reduction method to deposit tiny seeds of gold onto the copper sulphide surface. The resulting hybrid nanoparticles – less than 8 nm in size – can potentially travel inside tissues easily and reach tumours. The researchers believe that the nanoparticles’ small size would also allow them to leave the human body naturally without accumulating, although extensive studies have to be carried out to determine if they are safe to use inside the human body.  

In the current study, the researchers have tested their nanoparticles on lung cancer and cervical cancer cell lines in the lab. They now plan to take the results forward for clinical development.  

Here’s a link to and a citation for the paper,

Seed-Mediated Galvanic Synthesis of CuS–Au Nanohybrids for Photo-Theranostic Applications by Madhavi Tripathi, Swathi Padmanabhan, Jaya Prakash, and Ashok M. Raichur. ACS Appl. Nano Mater. 2023, 6, 16, 14861–14875 DOI: https://doi.org/10.1021/acsanm.3c02405 Publication Date:August 10, 2023 Copyright © 2023 American Chemical Society

This paper is behind a paywall.

Flesh-eating fungus, ivy and other inspirations from nature

Michael Berger has featured Dr. Mingjun Zhang’s team’s fascinating work on flesh-eating fungus in a Dec. 18, 2012 Spotlight article on Nanowerk,

“Most studies on naturally occurring organic nanoparticles have focused on higher organisms,” Mingjun Zhang, an associate professor of biomedical engineering at the University of Tennessee, Knoxville, tells Nanowerk. “Given the earth’s rich biological diversity, it is reasonable to hypothesize that naturally occurring nanoparticles, of various forms and functions, may be produced by a wide range of organisms from microbes to metazoans.”

In his research, Zhang has focused on looking at nature for inspirations for solutions to challenges in engineering and medicine, especially in small-scale, such as bioinspired nanomaterials, bioinspired energy-efficient propulsive systems, and bioinspired nanobio systems for interfacing with cellular systems.

In new work, Zhang and his research associate Dr. Yongzhong Wang have turned their focus to Arthrobotrys oligospora, a representative flesh eater with a predatory life stage in the fungal kingdom.

The researchers have published their work in Advanced Functional Materials ((early online publication behind a paywall),

Naturally Occurring Nanoparticles from Arthrobotrys oligospora as a Potential Immunostimulatory and Antitumor Agent by Yongzhong Wang, Leming Sun, Sijia Yi, Yujian Huang, Scott C. Lenaghan, and Mingjun Zhang in Advanced Functional Materials

Article first published online: 4 DEC 2012 DOI: 10.1002/adfm.201202619

Here’s the abstract,

Arthrobotrys oligospora, a representative flesh eater in the fungal kingdom, is a potential source for natural-based biomaterials due to the presence of specialized 3D adhesive traps that can capture, penetrate, and digest free-living nematodes in diverse environments. The purpose of this study is to discover novel nanoparticles that occur naturally in A. oligospora and to exploit its potential biomedical applications. A new culture method, fungal sitting drop culture method, is established in order to monitor the growth of A. oligospora in situ, and observe the nanoparticle production without interfering or contamination from the solid media. Abundant spherical nanoparticles secreted from the fungus are first revealed by scanning electron microscopy and atomic force microscopy. They have an average size of 360–370 nm, with a zeta potential of –33 mV at pH 6.0. Further analyses reveal that there is ≈28 μg of glycosaminoglycan and ≈550 μg of protein per mg of nanoparticles. Interestingly, the nanoparticles significantly induce TNF-α secretion in RAW264.7mouse macrophages, indicating a potential immunostimulatory effect. The nanoparticles themselves are also found slightly cytotoxic to mouse melanoma B16BL6 and human lung cancer A549 cells, and show a synergistic cytotoxic effect upon conjugation with doxorubicin against both cells. This study proposes a new approach for producing novel organic nanoparticles secreted from microorganisms under controlled conditions. The findings here also highlight the potential roles of the naturally occurring nanoparticles from A. oligospora as an immunostimulatory and antitumor agent for cancer immunochemotherapy.

In more generalized language (from Berger’s Spotlight article),

“It is really exciting to use a natural microbe system to produce nanoparticles for potential cancer therapy,” says Zhang. “Originally, we were trying to understand how the fungus secretes an adhesive trap that can capture, penetrate, and digest free-living nematodes in diverse environments. By doing that we almost accidentally discovered the nanoparticles produced.”

Zhang’s team investigated the fungal nanoparticles’ potential as a stimulant for the immune system, and found through an in vitro study that the nanoparticles activate secretion of an immune-system stimulant within a white blood cell line. They also investigated the nanoparticles’ potential as an antitumor agent by testing in vitro the toxicity to cells using two tumor cell lines, and discovered nanoparticles do kill cancer cells.

Berger’s article in addition to giving more details about Zhang’s current work and his work with ivy and possible applications for ivy-based nanoparticles in sunscreens also provides some discussion of naturally occurring nanoparticles as opposed to engineered (or man-made)  nanoparticles.

The University of Tennessee’s Dec. 4, 2012 press release is also a good source of information on Zhang’s latest work on flesh-eating fungus. For the indefatiguable who are interested in Zhang’s work on ivy and potential nanosunscreens, there’s also my July 22, 2010 posting.