Artificial nanomotors with advanced functions, such as motility and miniaturization, enabled the exploration of new strategies for cancer treatment. However, these nanorobots do not contain multiple functions that could help progress this technology rapidly.
In a recent study, researchers proposed a dual-source powered Janus nanomotor containing multiple photo-theranostic functions, for example, photodynamic therapy (PDT), surface-enhanced Raman scattering (SERS) sensing, photothermal therapy (PTT) and fluorescence imaging/photoacoustic imaging (PAI). This study is available as a pre-proof in Biomaterials.
Merits of Theranostics Approach in Biomedicine
The combination of diagnosis and therapy is referred to as theranostics. One of the key advantages of this strategy is that it enables image-guided therapy. Several light-sensitive bioimaging and therapeutic agents are available that allow remote controllability and non-invasiveness, with significant effectiveness.
Theranostic capacity has been immensely expanded with the development of PAI, which acts as micro/nano-carriers. Additionally, therapeutic methods, such as PDT and PTT, exhibited significant efficacy in cancer treatment. Although photo-theranostics has combined imaging and therapeutic modalities into a single platform for better clinical outcomes, formulating efficient imaging/therapy reagents has remained challenging.
Biomedically engineered micro-/nanomotors (MNMs) have been applied in microsurgery, minimally invasive treatment, and disease diagnosis. The development of synthetic MNMs-based nanoplatforms with active self-propulsion capacity at the nanoscale has enabled the precise targeting of tumor cells. Furthermore, this nanosystem is stable in the tumor microenvironment and has displayed enhanced cell and tissue penetration capacity. Therefore, the MNM-based nanoplatform has great potential in cancer photo-theranostics.
Development of Novel Nanomotors for Photo-Theranostics Application
Recently, researchers have designed a new photo-theranostic nanomotor by combining several diagnostic and therapeutic functions. They created up-converted nanoparticles (UCNPs) in multiple layered structures of NaYF4:Yb, Tm@NaYF4:Yb, and Nd@NaYF4, via thermal decomposition, whose average diameters were estimated to be approximately 29.1 nm, 42.7 nm, and 59.8 nm, respectively.
The UCNP nanocrystals were encapsulated by a mesoporous silica (mSiO2) coating layer, forming UCNPs@mSiO2 (UMS). Subsequently, the amino group was introduced onto the mSiO2 surface (UMS-NH2) and gold (Au) was sputtered to one side. Thereby, Au-functionalized Janus nanoparticles were formed, which were denoted as UCNP@mSiO2@Au (UMSA).
To equip the nanomotor with PDT, photosensitizer 5,10,15,20-tetrakis (4-aminophenyl) porphyrin (TAPP) was added to the surface of the mSiO2 forming UMSTA3. Scientists next modified TAPP with glutaraldehyde (GA). Finally, a catalase was added to UMSTA3 that served as a nano-engine to provide thrust force to the nanomotor (UMSTCA3). Because of its nanoscale dimension, UMSTCA3 nanomotors exhibited a high rotational diffusion coefficient
A specially designed software was written to measure the nanomotor trajectories. Analysis of the nanomotor trajectories showed higher H2O2 fuel concentrations promoted greater diffusiveness. Interestingly, the nanomotor’s motility could be increased by enhancing H2O2 concentration and application of NIR light.
The main functions of the UMSTCA3 nanomotor are to detect tumor cells, performing dual-modal bioimaging (PAI/FLI), and NIR-triggered phototherapy (PTT/PDT). This nanomotor uses H2O2 tumor biomarker sensing to achieve tumor cell sensing. PDT treatment is associated with producing reactive oxygen species (ROS) to eliminate tumor cells.
Taken together, the current multifunctional nanomotor is equipped with PTT, SERS, and PDT sensing functions. The combination of UCNPs and photosensitizer offers PDT, while the gold nano-shell offers SERS and PTT sensing.
Efficacy of Cancer Photo-Theranostics through in vivo and in vitro Studies
The photo-theranostic capability of the nanomotor was tested using cellular experiments and animal models. The biological safety profile of both UMSTA3 and UMSTCA3 nanomotors was analyzed. In vitro studies, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assays, demonstrated considerable biocompatibility and marginal cytotoxicity.
Compared to a single PTT treatment for cancer, UMSTCA3 nanomotors with synergistic phototoxicity of PTT and PDT eliminated cancer cells more efficiently. Additionally, the viability of cancer cells significantly decreased on elevating the NIR light dose. The live/dead assay also revealed that an increase in the NIR light significantly enhanced the number of dead cells.
Animal models were used to investigate the effectiveness of UMSTCA3 nanomotors in vivo. 4T1 tumor-bearing mice were injected with the newly designed nanomotors to test the effectiveness of nanomotors in cancer treatment. Tumor volumes of the treated mice were measured, and the result suggested that a single treatment of NIR laser irradiation or UMSTCA3 injection was insufficient to suppress cancer development. Maximum suppression of cancer cells was observed in mice treated with the combination of UMSTA3 and NIR laser at 808 nm.
In the future, more research is required to validate the findings. Also, the biocompatibility of the nanomotors needs to be assessed in further detail.
News
How Are Hydrogels Shaping the Future of Biomedicine?
Hydrogels have gained widespread recognition and utilization in biomedical engineering, with their applications dating back to the 1960s when they were first used in contact lens production. Hydrogels are distinguished from other biomaterials in [...]
Nanovials method for immune cell screening uncovers receptors that target prostate cancer
A recent UCLA study demonstrates a new process for screening T cells, part of the body's natural defenses, for characteristics vital to the success of cell-based treatments. The method filters T cells based on [...]
New Research Reveals That Your Sense of Smell May Be Smarter Than You Think
A new study published in the Journal of Neuroscience indicates that the sense of smell is significantly influenced by cues from other senses, whereas the senses of sight and hearing are much less affected. A popular [...]
Deadly bacteria show thirst for human blood: the phenomenon of bacterial vampirism
Some of the world's deadliest bacteria seek out and feed on human blood, a newly-discovered phenomenon researchers are calling "bacterial vampirism." A team led by Washington State University researchers has found the bacteria are [...]
Organ Architects: The Remarkable Cells Shaping Our Development
Finding your way through the winding streets of certain cities can be a real challenge without a map. To orient ourselves, we rely on a variety of information, including digital maps on our phones, [...]
Novel hydrogel removes microplastics from water
Microplastics pose a great threat to human health. These tiny plastic debris can enter our bodies through the water we drink and increase the risk of illnesses. They are also an environmental hazard; found [...]
Researchers Discover New Origin of Deep Brain Waves
Understanding hippocampal activity could improve sleep and cognition therapies. Researchers from the University of California, Irvine’s biomedical engineering department have discovered a new origin for two essential brain waves—slow waves and sleep spindles—that are critical for [...]
The Lifelong Cost of Surviving COVID: Scientists Uncover Long-Term Effects
Many of the individuals released to long-term acute care facilities suffered from conditions that lasted for over a year. Researchers at UC San Francisco studied COVID-19 patients in the United States who survived some of the longest and [...]
Previously Unknown Rogue Immune Key to Chronic Viral Infections Discovered
Scientists discovered a previously unidentified rogue immune cell linked to poor antibody responses in chronic viral infections. Australian researchers have discovered a previously unknown rogue immune cell that can cause poor antibody responses in [...]
Nature’s Betrayal: Unmasking Lead Lurking in Herbal Medicine
A case of lead poisoning due to Ayurvedic medicine use demonstrates the importance of patient history in diagnosis and the need for public health collaboration to prevent similar risks. An article in CMAJ (Canadian Medical Association [...]
Frozen in Time: How a DNA Anomaly Misled Scientists for Centuries
An enormous meteor spelled doom for most dinosaurs 65 million years ago. But not all. In the aftermath of the extinction event, birds — technically dinosaurs themselves — flourished. Scientists have spent centuries trying [...]
‘Mini kidneys’ reveal new insights into metabolic defects in polycystic kidney disease
Scientists at Nanyang Technological University, Singapore (NTU Singapore) have successfully grown 'mini kidneys' in the lab and grafted them into live mice, revealing new insights into the metabolic defects and a potential therapy for [...]
Decoding the Origin of Life: Scientists Solve Early Earth RNA Puzzle
Recent research illustrates how RNA molecules’ chemical characteristics might have played a crucial role in the development of complex life forms. How did complex life manage to evolve on the early, inhospitable Earth? Initially, [...]
Improving infectious disease testing with gold nanoparticles
By harnessing the power of composite polymer particles adorned with gold nanoparticles, a group of researchers have delivered a more accurate means of testing for infectious diseases. Details of their research was published in the [...]
New micromaterial releases nanoparticles that selectively destroy cancer cells
Researchers have developed micromaterials made up only of proteins, capable of delivering over an extended period of time nanoparticles that attack specific cancer cells and destroy them. The micromaterials mimic natural secretory granules found [...]
Alzheimer’s Breakthrough: Scientists Make Revolutionary Leap
Dementia is a major health issue worldwide in the 21st century, impacting over 50 million people globally. This figure is expected to soar to 152 million by 2050, as the global population ages. Alzheimer’s disease (AD) [...]
