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Innovative Nanomaterials for Cancer Therapy

NPG Asia Materials is proud to present a collection of articles on innovative nanomaterials for advanced therapy of cancer. The collection features a selection of recent articles that report multimodal nanoplatforms for photothermal therapy, 2D nanomaterials and their composites, cell-membrane nanoparticle camouflaging, surface-engineered nanobubbles, or 3D printed scaffolds, as well as a fundamentally novel approach of cell rupturing.

Original Articles

Multidrug-resistant breast cancers can be overcome with a carrier containing chemotherapies and laser-active nanorods coated with selenium. Multimodal agents employing nanomaterials are attracting attention for treating multidrug-resistant cancer cells. In particular, recent studies suggest that anticancer agents combined with selenium could reduce toxic side-effects during treatment of stubborn, metastatic tumors. Jong Oh Kim at Korea’s Yeungnam University and colleagues have now added another cancer-killing technique to the co-delivery approach—using light-absorbing nanorods to heat tumor cells. The team used this laser sensitivity for on-demand release of doxorubicin drugs from a silica-nanoparticle carrier holding selenium-covered gold nanorods. Additional in vitro and mouse tests revealed that the nanomedicine enhanced tumor cell death, partly through suppressing critical signaling pathways. The absence of organ damage during animal testing bodes well for future clinical trials of selenium-based drug delivery.

Article | open | | NPG Asia Materials

Graphene oxide nanosheets decorated with molybdenum and drug agents show promising action against lung metastatic cancer cells in live mice. Unlike other nanomaterials, graphene-based compounds can appear in the lungs after being captured by capillary cells. This accumulation sometimes produces toxic side-effects, but a team led by Sijin Liu from the Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, reports better biocompatibility with graphene oxide-molybdenum disulfide composites. Interlayering of the two sheet-like components produced a substance well suited for aqueous environments and with strong affinity for chemotherapeutic agents such as doxorubicin. Experiments revealed that drug-loaded nanocomposites exhibited preferential targeting of the lungs and substantially inhibited metastatic tumor growth in the lungs of mice. Biosafety improvements were attributed to a reduction in macrophage interactions due to the nanosheets' lack of active oxygen-based surface species.

Original Article | open | | NPG Asia Materials

A simple method of synthesizing nanosheets of black phosphorus, demonstrated by researchers in South Korea, could help the development of a therapy that destroys cancer cells. Black phosphorus comprises weakly bound layers of atoms. Nanosheets just a few layers thick are known to be useful in photothermal therapy: the black phosphorus absorbs laser light, gets hot and destroys any nearby cells. Existing methods of synthesizing these nanosheets are time-consuming and require harsh chemicals. Instead, Jeong Hoon Byeon from Yeungnam University, Gyeongsan, and colleagues continuously produced black phosphorus nanosheets by simply heating red phosphorus, an alloy of gold and tin, and iodine. The team demonstrated that injection of these nanosheets under the skin in mice and subsequent illumination with infrared laser light led to tumor regression.

Article | open | | NPG Asia Materials

A strategy that relies on polysaccharides and gold nanorods to realize cancer therapy shows promise in live animal studies. In photothermal therapy, nanoparticles in cancerous tissue convert laser light into heat and damage tumors while leaving surrounding healthy tissue unharmed. Nana Zhao and Fu-Jian Xu from the Beijing University of Chemical Technology in China and colleagues synthesized polysaccharide-based nanocapsules that can encapsulate photothermal gold nanorods (pullulan-gold nanocomposites), and simultaneously target asialoglycoprotein receptor overexpressed liver cancer cells. Using real-time confocal laser scanning microscopy, the team demonstrated that the nanocomposites rapidly accumulated around the nuclei of hepatoma cells, where acidic conditions dissolved the polysaccharide matrix and unleashed gold nanorods with the assistance of glutathione. Images taken after photothermal therapy in mice revealed massive shrinking of cancerous cells and fragmented nuclei, with no side effects on major organs.

Article | open | | NPG Asia Materials

Graphene-oxide particles inserted into the body for biomedical applications such as drug delivery or enhanced imaging can form aggregates over time with possible adverse effects on health, and show researchers in China. After the medical objectives have been achieved, the nanoparticles often remain inside the human body, but it is unclear what happens to them after long time periods in a biological environment. Sijin Liu from the Chinese Academy of Sciences in Beijing, Wei Chen from Nankai University in Tianjin, and their colleagues show that graphene-oxide nanoparticles undergo a physicochemical transformation in simulated human lung fluids, aggregating to form larger particles. This reduces their interaction with cells and inhibits cellular uptake, and can induce proinflammatory reactions. The results highlight the need to consider the biosafety of nanomaterials and their potential long-term side effects.

Article | open | | NPG Asia Materials

A method for three-dimensional printing of replacement bone that allows destruction of cancerous cells has been developed by scientists in China. Sometimes the only clinical approach to bone cancer is surgery that removes the affected tissue and replaces it with an artificial substitute. In the case of cortical bone, the dense tissue on a bone’s surface, the engineered biomaterial needs to be of very high strength. Chengtie Wu from the Shanghai Institute of Ceramics, CAS and colleagues demonstrated an iron-calcium silicate composite scaffold that is simple to produce and has the strength necessary to support the human body. The team used composite scaffold because it can be heated by near infrared light to kill residual cancer cells, a technique known as photothermal therapy. Adding iron increased the strength of the scaffold.

Article | open | | NPG Asia Materials

A hydrogel that uses physical force rather than drugs or radiation to kill breast and lung cancer cells has been developed. The approach by Siowling Soh at the National University of Singapore and colleagues exploits the temperature responsiveness of soft, watery polymers known as poly(N-isopropylacrylamides). The researchers coated the hydrogel with cell-adhering arginine-glycine-aspartate peptides, using a dopamine and lysine co-polymer to anchor the biomolecules. After seeding cancer cells onto the peptide-coated hydrogel, they dropped sample temperatures from 37°C to 22°C. The hydrogel expanded due to a phase transition, providing a force large enough to rupture the cancer cells attached to the surface — an easy-to-implement strategy effective for particles made of these coated hydrogels with sizes ranging from micrometers to millimeters. Measurements revealed the hydrogels can apply enough force to rupture a variety of cell types.

Original Article | open | | NPG Asia Materials

A bifunctional scaffold was successfully prepared by in situ growth of MoS2 nanosheets on the 3D-printed bioceramic scaffolds via a facile hydrothermal process. The prepared scaffolds exhibit an excellent capability for both tumor therapy and tissue regeneration, offering a promising clinical strategy for effective treatment of tumor-induced tissue defects.

Original Article | open | | NPG Asia Materials

A nanomaterial that can improve infrared, magnetic resonance and ultrasound imaging of tumors, while also delivering drugs for chemotherapy has been developed by researchers in China. Nanoparticles with an appropriate coating can attach exclusively to cancer cells. They can be imaged from outside the body, allowing doctors to identify the cancer’s location and track its spread, and can also carry drugs to be released when the particles reach their target. Combining diagnosis and therapy into a single step, known as theranostics, leads to better patient care. Daxiang Cui and co-workers from the Shanghai Jiao Tong University made nanoparticles that included gadolinium ions for magnetic resonance imaging, a fluorescent dye for imaging and the drug that is released when stimulated by laser light. These nanoparticles exhibited selective accumulation and long retention in tumors in mice.

Article | open | | NPG Asia Materials

Non-toxic nanoparticles that can target tumors and aid the treatment of cancer have been developed and tested by scientists in China. Nanoparticles injected into the body can improve the resolution of medical scans, or carry therapeutic drugs through the body. Nanoparticles that can achieve both simultaneously are particularly important because they enable multiple different types of therapy. Tianfeng Chen from Jinan University, Zhuang Liu from Soochow University and co-workers made nanoparticles containing the chemotherapeutic drug doxorubicin and the imaging agent indocyanine green, which they coated with membrane from a cancer cell. These nanoparticles accumulated in mouse tumors where they could both deliver drugs for chemotherapy and act as targets for hyperthermia therapy and radiotherapy, all without having any toxic side effects on major organs.

Article | open | | NPG Asia Materials