Abundance and Metabolism Disruptions of Intratumoral Microbiota by Chemical and Physical Actions Unfreeze Tumor Treatment Resistance.

Intratumoral or intestinal microbiota correlates with tumorigenesis and progression, and microbiota regulation for reinforcing various anti-tumor approaches is of significant importance, which, however, suffers from no precise regulation method and unclear underlying mechanism. Herein, a microbiome metabolism-engineered phototherapy strategy is established, wherein Nb2 C/Au nanocomposite and the corresponding phototherapy are harnessed to realize "chemical" and "physical" bacterial regulations. Flora analysis and mass spectrometry (MS) and metabonomics combined tests demonstrate that the synergistic microbiota regulations can alter the abundance, diversity of intratumoral microbiome, and disrupt metabolic pathways of microbiome and tumor microenvironment, wherein the differential singling pathways and biosynthetic necessities or metabolites that can affect tumor progression are identified. As well, anti-TNFα is introduced to unite with bacterial regulation to synergistically mitigate bacterial-induced inflammation, which, along with the metabolism disruptions of intratumoral microbiota and tumor microenvironment, unfreezes tumor resistance and harvests significantly-intensified phototherapy-based anti-tumor outcomes against 4T1 and CT26 tumors. The clear underlying principles of microbiome-regulated tumorigenesis and the established microbiome metabolism regulation method provide distinctive insights into tumor therapy, and can be also extended to other gut microbiome-associated lesions interference.

Biodegradable and Excretable 2D W1.33 C i-MXene with Vacancy Ordering for Theory-Oriented Cancer Nanotheranostics in Near-Infrared Biowindow.

MXenes, a new class of two-dimensional (2D) nanomaterials, have shown enormous potential for biological applications. Notably, the development of 2D MXenes in nanomedicine is still in its infancy. Herein, a distinct W1.33 C i-MXene with multiple theranostic functionalities, fast biodegradation, and satisfactory biocompatibility is explored. By designing a parent bulk laminate in-plane ordered (W2/3 Y1/3 )2 AlC ceramic and optionally etching aluminum (Al) and yttrium (Y) elements, 2D W1.33 C i-MXene nanosheets with ordered divacancies are efficiently fabricated. Especially, theoretical simulations reveal that W1.33 C i-MXene possesses a strong predominance of near-infrared (NIR) absorbance. The constructed ultrathin W1.33 C nanosheets feature excellent photothermal-conversion effectiveness (32.5% at NIR I and 49.3% at NIR II) with desirable biocompatibility and fast degradation in normal tissue rather than in tumor tissue. Importantly, the multimodal-imaging properties and photothermal-ablation performance of W1.33 C-BSA nanosheets are systematically revealed and demonstrated both in vitro and in vivo. The underlying mechanism and regulation factors for the W1.33 C-BSA nanosheets-induced hyperthermia ablation are also revealed by transcriptome and proteome sequencing. This work offers a paradigm that i-MXenes achieve the tailoring biomedical applications through composition and structure design on the atomic scale.

Extravascular gelation shrinkage-derived internal stress enables tumor starvation therapy with suppressed metastasis and recurrence.

Despite the efficacy of current starvation therapies, they are often associated with some intrinsic drawbacks such as poor persistence, facile tumor metastasis and recurrence. Herein, we establish an extravascular gelation shrinkage-derived internal stress strategy for squeezing and narrowing blood vessels, occluding blood & nutrition supply, reducing vascular density, inducing hypoxia and apoptosis and eventually realizing starvation therapy of malignancies. To this end, a biocompatible composite hydrogel consisting of gold nanorods (GNRs) and thermal-sensitive hydrogel mixture was engineered, wherein GRNs can strengthen the structural property of hydrogel mixture and enable robust gelation shrinkage-induced internal stresses. Systematic experiments demonstrate that this starvation therapy can suppress the growths of PANC-1 pancreatic cancer and 4T1 breast cancer. More significantly, this starvation strategy can suppress tumor metastasis and tumor recurrence via reducing vascular density and blood supply and occluding tumor migration passages, which thus provides a promising avenue to comprehensive cancer therapy.