Recent Research on Methods to Improve Tumor Hypoxia Environment

Abstract

Cancer is a major disease burden worldwide. In recent years, in addition to surgical resection, radiotherapy and chemotherapy are recognized as the most effective methods for treating solid tumors. These methods have been introduced to treat tumors of different origins and stages clinically. However, due to insufficient blood flow and oxygen (O2) supply in solid tumors, hypoxia is caused, leading to decreased sensitivity of tumor cells and poor therapeutic effects. In addition, hypoxia will also lead to resistance to most anticancer drugs, accelerate malignant progress, and increase metastasis. In solid tumors, adequate O2 supply and adequate delivery of anticancer drugs are essential to improve radiotherapy and chemotherapy sensitivity. In recent decades, the researches on relieving tumor hypoxia have attracted researchers’ extensive attention and achieved good results. However, as far as we know, there is no detailed review of the researches on alleviating tumor hypoxia. Therefore, in this contribution, we hope to give an overview of the researches on methods to improve tumor hypoxia environment and summarize their effect and application in tumor therapy, to provide a methodological reference for the research and development of new antitumor agents.

Recent Advances in Nanoplatform Construction Strategy for Alleviating Tumor Hypoxia

“…It is one of the important strategies to improve tumor oxygen content through constructing a direct O 2 delivery nanoplatform and then delivering O 2 into the hypoxic TME. [ 25 ] For RT and chemotherapy, relieving tumor hypoxia can improve the sensitivity of tumor cells to radiation and chemotherapeutic drugs and enhance the therapeutic effect. For some catalytic treatments involving oxygen, carrying oxygen can provide more raw materials to enhance catalytic treatment.…”

Mn3O4 Nanoshell Coated Metal–Organic Frameworks with Microenvironment‐Driven O2 Production and GSH Exhaustion Ability for Enhanced Chemodynamic and Photodynamic Cancer Therapies

“…[ 27 ] Hypoxia also exacerbates the abnormal metabolism of cancer cells resulting in an acidic environment of tumor tissue, leading to a significant increase in H 2 O 2 inside the tumor. [ 28 ] Although PDT combined with cancer treatments has some benefits, it is affected by the tumor microenvironment (TME). [ 29 ] Oxygen is the key substrate of PDT.…”

ALA/Ag2S/MnO2 Hybrid Nanoparticles for Near-Infrared Image-Guided Long-Wavelength Phototherapy of Breast Cancer

“…Since PDT is an oxygen-dependent process, the hypoxic environment at the tumor site is an obstacle to ROS generation and limits the therapeutic effect of PDT. , Therefore, possibilities for in situ oxygen-production at the tumor site have been investigated . Nanocrystalline MnO 2 undergoes Fenton-like reaction in the acidic microenvironment of tumors (eqs and ), oxidizing endogenous hydrogen peroxide and producing oxygen and toxic hydroxide radicals, which is indeed also recognized as chemodynamic therapy (CDT). , Ni et al have shown the decomposition of H 2 O 2 to generate O 2 using CuS NPs wrapped on the surface of upconversion NPs via MnO 2 coating.…”