Recent Advances in Green Metallic Nanoparticles for Enhanced Drug Delivery in Photodynamic Therapy: A Therapeutic Approach

Abstract

Globally, cancer is one of the leading causes of death among men and women, it is characterized by the unregulated proliferation of tumor cells. Some of the common risk factors associated with cancer development include the consistent exposure of body cells to carcinogenic agents such as alcohol, tobacco, toxins, gamma rays and alpha particles. Besides the above-mentioned risk factors, conventional therapies such as radiotherapy, and chemotherapy have also been linked to the development of cancer. Over the past decade, tremendous efforts have been invested in the synthesis of eco-friendly green metallic nanoparticles (NPs), and their medical application. Comparatively, metallic NPs have greater advantages over conventional therapies. Additionally, metallic NPs can be functionalized with different targeting moieties e.g., liposomes, antibodies, folic acid, transferrin, and carbohydrates. Herein, we review and discuss the synthesis, and therapeutic potential of green synthesized metallic NPs for enhanced cancer photodynamic therapy (PDT). Finally, the advantages of green hybridized activatable NPs over conventional photosensitizers (PSs) and the future perspectives of nanotechnology in cancer research are discussed in the review. Furthermore, we anticipate that the insights offered in this review will inspire the design and development of green nano-formulations for enhanced image-guided PDT in cancer treatment.

Recent Innovations of Mesoporous Silica Nanoparticles Combined with Photodynamic Therapy for Improving Cancer Treatment

“…In the first possibility, the PS in the excited singlet state S 1 is supposed to have a very short lifetime, so it returns to the ground state by emitting photon energy in the form of fluorescence emission. This type of photophysical process is used for photodynamic diagnosis (PDD) ( Figure 4 a) [ 5 , 6 ]. The second possibility is when the multiplication of the PS is transferred from the singlet state to the triplet state (T 1 ) through intersystem crossing (ISC) to reach the first triplet excited state (T 1 ).…”

“…Photodynamic therapy can be classified into two major photochemical pathways (Type I and Type II). Both pathways lead to ROS and free radical generation upon activation with PDT process [ 5 , 41 ]. Electron transfer or/and hydrogen abstraction occurs between the substrates and photosensitizers for type I, generating free radicals.…”

“… Modified Jablonski energy diagram, representing the photochemical and photophysical reactions of photosensitizers in ( a ) photodynamic diagnosis (PDD) and ( b ) photodynamic therapy (PDT) [ 5 ]. …”

“…In 2020, more than 19.2 million new cancer cases were diagnosed, and around 9.9 million patients died worldwide [ 4 ]. This number is predicted to rise by 70% by 2040 [ 5 ]. Many studies have reported that alcohol, advanced age, smoking, genetic mutations, hormonal imbalances, and poor lifestyle can contribute to cancer development [ 2 , 5 ].…”

“…This number is predicted to rise by 70% by 2040 [ 5 ]. Many studies have reported that alcohol, advanced age, smoking, genetic mutations, hormonal imbalances, and poor lifestyle can contribute to cancer development [ 2 , 5 ]. Nowadays, different types of clinical treatments for cancer are being used, such as radiotherapy, chemotherapy, and surgery.…”