NIR-II light triggered burst-release cascade nanoreactor for precise cancer chemotherapy.

The current strategy of co-delivering copper ions and disulfiram (DSF) to generate cytotoxic CuET faces limitations in achieving rapid and substantial CuET production, specifically in tumor lesions. To overcome this challenge, we introduce a novel burst-release cascade reactor composed of phase change materials (PCMs) encapsulating ultrasmall Cu2-xSe nanoparticles (NPs) and DSF (DSF/Cu2-xSe@PCM). Once triggered by second near-infrared (NIR-II) light irradiation, the reactor swiftly releases Cu2-xSe NPs and DSF, enabling catalytic reactions that lead to the rapid and massive production of Cu2-xSe-ET complexes, thereby achieving in situ chemotherapy. The mechanism of the burst reaction is due to the unique properties of ultrasmall Cu2-xSe NPs, including their small size, multiple defects, and high surface activity. These characteristics allow DSF to be directly reduced and chelated on the surface defect sites of Cu2-xSe, forming Cu2-xSe-ET complexes without the need for copper ion release. Additionally, Cu2-xSe-ET has demonstrated a similar (to CuET) anti-tumor activity through increased autophagy, but with even greater potency due to its unique two-dimensional-like structure. The light-triggered cascade of interlocking reactions, coupled with in situ explosive generation of tumor-suppressive substances mediated by the size and valence of Cu2-xSe, presents a promising approach for the development of innovative nanoplatforms in the field of precise tumor chemotherapy.

Hyaluronic Acid-Based Nanocarriers for Anticancer Drug Delivery.

Hyaluronic acid (HA), a main component of the extracellular matrix, is widely utilized to deliver anticancer drugs due to its biocompatibility, biodegradability, non-toxicity, non-immunogenicity and numerous modification sites, such as carboxyl and hydroxyl groups. Moreover, HA serves as a natural ligand for tumor-targeted drug delivery systems, as it contains the endocytic HA receptor, CD44, which is overexpressed in many cancer cells. Therefore, HA-based nanocarriers have been developed to improve drug delivery efficiency and distinguish between healthy and cancerous tissues, resulting in reduced residual toxicity and off-target accumulation. This article comprehensively reviews the fabrication of anticancer drug nanocarriers based on HA in the context of prodrugs, organic carrier materials (micelles, liposomes, nanoparticles, microbubbles and hydrogels) and inorganic composite nanocarriers (gold nanoparticles, quantum dots, carbon nanotubes and silicon dioxide). Additionally, the progress achieved in the design and optimization of these nanocarriers and their effects on cancer therapy are discussed. Finally, the review provides a summary of the perspectives, the lessons learned so far and the outlook towards further developments in this field.

Intra-articular injection of human umbilical cord mesenchymal stem cells ameliorates monosodium iodoacetate-induced osteoarthritis in rats by inhibiting cartilage degradation and inflammation.

AIMS: This study aimed to investigate whether human umbilical cord mesenchymal stem cells (UC-MSCs) can prevent articular cartilage degradation and explore the underlying mechanisms in a rat osteoarthritis (OA) model induced by monosodium iodoacetate (MIA). METHODS: Human UC-MSCs were characterized by their phenotype and multilineage differentiation potential. Two weeks after MIA induction in rats, human UC-MSCs were intra-articularly injected once a week for three weeks. The therapeutic effect of human UC-MSCs was evaluated by haematoxylin and eosin, toluidine blue, Safranin-O/Fast green staining, and Mankin scores. Markers of joint cartilage injury and pro- and anti-inflammatory markers were detected by immunohistochemistry. RESULTS: Histopathological analysis showed that intra-articular injection of human UC-MSCs significantly inhibited the progression of OA, as demonstrated by reduced cartilage degradation, increased Safranin-O staining, and lower Mankin scores. Immunohistochemistry showed that human UC-MSC treatment down-regulated the expression of matrix metalloproteinase-13 (MMP13) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), and enhanced the expression of type II collagen and ki67 in the articular cartilage. Furthermore, human UC-MSCs significantly decreased the expression of interleukin (IL)-1ß and tumour necrosis factor-α (TNF-α), while increasing TNF-α-induced protein 6 and IL-1 receptor antagonist. CONCLUSION: Our results demonstrated that human UC-MSCs ameliorate MIA-induced OA by preventing cartilage degradation, restoring the proliferation of chondrocytes, and inhibiting the inflammatory response, which implies that human UC-MSCs may be a promising strategy for the treatment of OA. Cite this article: Bone Joint Res 2021;10(3):226-236.

[Analysis of gas absorption coefficient at various pressures].

The absorption coefficient alpha(v) of gas plays an important role in quantitative analysis of pollution gases and theoretical investigation of molecular parameter. In this paper we first analyze alpha(v) theoretically and present a calculation method. Then we analyze 2v3 band R3 manifold of pure CH4 and draw a conclusion that alpha(v0) decreases and the peak absorption kappa(v0) increases with increasing the pressure. When the pressure is <0.03 and >2 atm, we can calculate alpha(v0) using the Gaussian profile and Lorentzian profile respectively, and then analyze the relative error. Finally we analyze the peak absorption kappa(v0) at various pressures, then define the high-resolution area and high-sensitive area respectively when the pressure is <0.01 and >1 atm.