Twins-like nanodrugs synchronously transport in blood and coalesce inside tumors for sensitive ultrasound imaging and triggerable penetrative drug delivery

Nanodrugs capable of aggregating in the tumor microenvironment(TME)have demonstrated great efficiency in improving the therapeutic outcome.Among vari-ous approaches,the strategy utilizing electrostatic interaction as a driving force to achieve intratumor aggregation of nanodrugs has attracted great attention.However,the great difference between the two nanodrugs with varied physicochemical prop-erties makes their synchronous transport in blood circulation and equal-opportunity tumor uptake impossible,which significantly detracts from the beneficial effects of nanodrug aggregation inside tumors.We herein propose a new strategy to construct a pair of extremely similar nanodrugs,referred to as“twins-like nanodrugs(TLNs)”,which have identical physicochemical properties including the same morphology,size,and electroneutrality to render them the same blood circulation time and tumor entrance.The 1:1 mixture of TLNs(TLNs-Mix)intravenously injected into a mouse model efficiently accumulates in tumor sites and then transfers to oppositely charged nanodrugs for electrostatic interaction-driven coalescence via responding to matrix metalloproteinase-2(MMP-2)enriched in tumor.In addition to enhanced tumor retention,the thus-formed micron-sized aggregates show high echo intensity essen-tial for ultrasound imaging as well as ultrasound-triggered penetrative drug delivery.Owing to their distinctive features,the TLNs-Mix carrying sonosensitizer,immune adjuvant,and ultrasound contrast agent exert potent sonodynamic immunotherapy against hypovascular hepatoma,demonstrating their great potential in treating solid malignancies.

Biomimetic albumin-modified gold nanorods for photothermo-chemotherapy and macrophage polarization modulation

Nanotechnology-based photothermal therapy has attracted great attention in the past decade. Nevertheless, photothermal therapy has some inherent drawbacks, such as the uneven heat production and limited laser penetration, often leading to insufficient treatment outcomes. Here, we developed a combination strategy to improve cancer therapy. The biomimetic albumin-modified gold nanorods(AuNRs) were prepared with incorporation of paclitaxel(PTX). This therapeutic system was characterized by several features. First, the albumin modification enhanced the biocompatibility and colloidal stability. Second, the surface-coated albumin promoted cellular uptake via the albumin-binding protein pathway. Third, PTX was incorporated via hydrophobic interaction between PTX and the albumin lipophilic domain. Fourth, the system can be used for combined photothermo-chemotherapy for yielding synergistic effects. The antitumor activity of the system was evaluated both in vitro and in vivo using the HCT116 colon cancer cell and tumor model. The combination therapy was found with an enhanced treatment efficiency and no obvious side effect. Most importantly, the thermal effect was also discovered with the ability to modulate the tumor microenvironments and suppress the macrophages polarization towards the M2 pro-tumor phenotype. It could be a mechanism for photothermal immunotherapy. The combination strategy and the system provide a potential method for cancer therapy.