Advances in two-photon absorption photodynamic therapy of glioma based on porphyrin-based metal-organicframework composites.

• How to improve the tissue penetration ability of PDT and improve the therapeutic effect on deep tumors is the first attempt to give our clinical ideas: 1. Improve porous NMOF sulfur quantum dots within one or two Windows of two photon or three photon absorption cross section. The filling rate of CHN QDS in porous NMOFs and the nature of CHN QDS themselves greatly affect the multiphoton absorption of excitation light by nanoparticle composites and thus the singlet oxygen generation efficiency. 2. To improve the filling rate of chedulide QDS by optimizing the filling conditions of chedulide precursors and the size and uniformity of NMOF pores; by changing the structure and composition of quantum dots, the absorption peak position and absorption coefficient are precisely adjusted to improve the multi-photon absorption ability of quantum dots. The energy transfer efficiency of the excited sulfur QDS is also an important factor affecting the efficiency of singlet oxygen generation. amongst them, the energy level matching between the sulfur quantum dot and the porphyrin ring is the key. Vasp, Win 2 K and Gaussian series software were used to simulate the energy level structure of the material, and the optimal energy level matching structure was explored combined with experiments. • Put forward the technical points that need to be overcome: (1) master the modulation law of two-photon absorption or three-photon absorption cross section to obtain higher energy transfer efficiency. (2) synthesize one or more nano photosensitizers capable of achieving efficient two - or three-photon absorption photodynamic therapy in infrared single window (860 nm) and dual window (1320 nm). Gliomas of the brain are characterised by high aggressiveness, high postoperative recurrence rate, high morbidity and mortality, posing a great challenge to clinical treatment. Traditional treatments include surgery, radiotherapy and chemotherapy; they also have significant associated side effects, leading to difficulties in tumour resection and recurrence. Photodynamic therapy has been shown to be a promising new strategy to help treat malignant tumours of the brain. It irradiates the tumour site at a specific wavelength to activate a photosensitiser, which selectively accumulates at the tumour site, triggering a photochemical reaction that destroys the tumour cells. It has the advantages of being minimally invasive, highly targeted and with few adverse reactions, and is expected to be well used in anti-tumour therapy. However, the therapeutic effect of traditional PDT is limited by the weak tissue penetration ability of photosensitiser, hypoxia and immunosuppression in the tumour microenvironment. This paper reviews the current research status on the therapeutic principle of photodynamic therapy in glioma and the mechanism of tumour cell injury, and also analyses the advantages and disadvantages of the current application in glioma treatment, and clarifies the analysis of ideas to improve the tissue penetration ability of photosensitizers. It aims to provide a feasible direction for the improvement of photodynamic therapy for glioma and a reference for the clinical treatment of deep brain tumours. [ABSTRACT FROM AUTHOR]