Cold Atmospheric Plasma Activates Selective Photothermal Therapy of Cancer.

Due to the body's systemic distribution of photothermal agents (PTAs), and to the imprecise exposure of lasers, photothermal therapy (PTT) is challenging to use in treating tumor sites selectively. Striving for PTT with high selectivity and precise treatment is nevertheless important, in order to raise the survival rate of cancer patients and lower the likelihood of adverse effects on other body sections. Here, we studied cold atmospheric plasma (CAP) as a supplementary procedure to enhance selectivity of PTT for cancer, using the classical photothermic agent's gold nanostars (AuNSs). In in vitro experiments, CAP decreases the effective power of PTT: the combination of PTT with CAP at lower power has similar cytotoxicity to that using higher power irradiation alone. In in vivo experiments, combination therapy can achieve rapid tumor suppression in the early stages of treatment and reduce side effects to surrounding normal tissues, compared to applying PTT alone. This research provides a strategy for the use of selective PTT for cancer, and promotes the clinical transformation of CAP.

Gum polysaccharide/nanometal hybrid biocomposites in cancer diagnosis and therapy.

Biopolymers are of prime importance among which gum polysaccharides hold an eminent standing owing to their high availability and non-toxic nature. Gum biopolymers offer a greener alternative to synthetic polymers and toxic chemicals in the synthesis of metal nanostructures. Metal nanostructures accessible via eco-friendly means endow astounding characteristics to gum-based biocomposites in the field of diagnosis and therapy towards cancer diseases. In this review, assorted approaches for the assembly of nanomaterials mediated by gum biopolymers are presented and their utility in cancer diagnosis and therapy, e.g., bioimaging, radiotherapy, and phototherapy, are deliberated to provide a groundwork for future stimulative research.

Fluorescence-enhanced covalent organic framework nanosystem for tumor imaging and photothermal therapy.

Fluorescent dyes, as a key factor in fluorescence imaging, usually exhibit a low signal-to-noise ratio (SNR) due to the limited loading capacities of delivery systems (usually less than 10.0 wt%) and their uncontrolled release. Herein, we developed a type of pH-responsive nanoplatform (MnO2/ZnCOF@Au&BSA) based on a zinc porphyrin covalent organic framework (COF), in which the zinc porphyrin (ZnPor) loading rate is 22.5 wt%. At pH = 7.4, the interlinked ZnPor in the assembly state did not show a fluorescence signal ("off" state). Together with the pH-triggered disintegration of ZnCOF in tumor cells (pH = 5.5), the scattered ZnPor displayed an obvious fluorescence signal recovery ("on" state). Simultaneously, the shed BSA-coated gold nanoparticles ingeniously caused the fluorescence signal to be further amplified through the metal-enhanced fluorescence effect, which was about 3.0-fold higher in vivo than in the free ZnPor group. Combined with the excellent photothermal therapy effect by the nanoplatform itself with the tumor inhibition rate of 79.5%, this nanosystem effectively solves the problem of low loading capacities and imaging SNR by traditional delivery systems, and successfully develops the potential of COFs for fluorescence imaging, achieving the purpose of integration of diagnosis and treatment.

Near-infrared-light induced nanoparticles with enhanced tumor tissue penetration and intelligent drug release.

Tumor tissue presents much denser and stiffer extracellular matrix (ECM), which can hinder the penetration of most nanoparticles (NPs) and contribute to the tumor cell proliferation. Here, NIR-activated losartan was encapsulated in hollow mesoporous prussian blue nanoparticles (HMPBs) to degrade ECM. The results showed that losartan enhanced the penetration of DOX, 1.47% of the injected dose (ID) of DOX reached the tumor tissues, which was 3.00-fold higher than the control group (0.49%). In addition, as the existence of thermo-sensitive lauric acid, (Losartan + DOX)@HMPBs could achieve near "zero drug leakage" during blood circulation, so as to reduce the damage of DOX to normal tissues. Furthermore, the animal experiments proved tumor inhibition ability of (Losartan + DOX)@HMPBs in synergistic of photothermal/chemotherapy, with the tumor growth inhibition rate of 81.3%. Taken together, these findings can be a candidate for developing vectors with enhanced tumor penetration and therapeutic effect in future clinical application. STATEMENT OF SIGNIFICANCE: Due to the existence of denser extracellular matrices (ECM), only 0.7% of the administered nanoparticles dose is delivered to tumor, which will limit the tumors' therapeutic effect. Degradation of ECM can improve the penetration of nanoparticles in tumors. However, no researchers has encapsulated losartan in nanoparticles to degrade ECM. Herein, we developed a NIR induced losartan and DOX co-delivery system based on hollow mesoporous prussian blue nanoparticles (HMPBs) to degrade ECM and improve the penetration of nanoparticles in tumors. The prepared nanoparticles can also acheive near "zero drug leakage" during blood circulation and "fixed-point drug release" in tumor, so as to reduce the damage of DOX to normal tissues. We believe the prepared nanoparticles provide a new platform for cancer treatment.