To synthesize CBM, two approaches have been employed (i) top-down: reduction of size from bulk materials, such as mechanical or chemical exfoliation, and (ii) bottom-up: construction from the atomic level, like epitaxial growth and chemical vapor deposition. Concerning the latter, some authors have even proposed using residues such as bio-mass and polymers waste. Nevertheless, it is worth noting that the properties of any CBM vary according to their specific structure (size and shape), which is determined by the method of synthesis, along with their experimental conditions and carbon source nature. Carbon-Based Materials (CBM) Applied in Photodynamic (PDT) and Photothermal (PTT) TherapiesĬBM have been considered a phototherapy agent due to their remarkable features. Thus, the doping and hybrid behavior of CBM along with synergistic therapies are also addressed in this review.Ģ. Phototherapy agents can also be loaded with drugs or combined with other materials to enhance their antitumoral action or to improve and modulate their properties, making possible the effective application of distinct mechanisms of action. These materials are critical components due to their remarkable advantages, such as reduced side effects and low toxicity in specific concentrations. The specificity of CBM accomplishes focusing its action only on cancerous cells. On this basis, carbon-based materials (CBM) have become excellent candidates as phototherapy agents and as platforms or carriers of these compounds. Furthermore, high specificity, biocompatibility, low dark toxicity, and optical characteristics are desirable. In both therapies, PDT and PTT, particular properties in their active agents are required, as well as robust responses to light stimuli. Thus, the targeting capability of PSs and PAs in tumor cells is key to concentrating their action in cancer tissue. ![]() When the temperature of the PAs surrounding the environment rises, cancerous cells are destroyed due to their low heat tolerance compared to normal cells. By non-radiative relaxation pathways, heat is generated to dissipate this excess of energy. The PAs are irradiated by light and they absorb photons which produces an excited state. The efficiency of PDT is related to the ROS generation yield, which depends on the PS, dose, source light, and tissue oxygen. In cancer treatments, this action results in apoptosis, necrosis, or autophagy of the abnormal cells inhibiting the tumor growth. In this state, the PS reacts with nearby molecular oxygen and generates ROS, either type I (free radicals) or type II (singlet oxygen, 1O 2) reactions. When light of a suitable wavelength is irradiated upon a defined molecule photosensitizer (PS) or photothermal agent (PA), reactive oxygen species (ROS) and heat are generated, respectively, in PDT and PTT, which causes damage to malignant cells in cancer. Photodynamic therapy (PDT) and photothermal therapy (PTT) are encompassed within phototherapy. To overcome these weaknesses, novel flexible light sources and devices have been designed, and approaches such as X-ray radiation, NIR light, and internal self-luminescence have been proposed. Nevertheless, it has drawbacks as poor penetration limits its action in optically inaccessible deep tumors. It is worth noting that phototherapy is advantageous compared to radiotherapy, chemotherapy, or surgery owing to its simple operation, minimally invasive procedure, reduced toxicity, minor trauma, fewer adverse reactions, and negligible drug resistance. Thus, several studies have proposed phototherapy using nanomaterials as photoabsorbing agents as an alternative to treat cancer. The International Agency for Research on Cancer reported 9.9 million worldwide diseases in 2020 (world ASR of 100.7). Likewise, various diseases such as vitiligo, psoriasis, atopic dermatitis, cancer, and so on, have been diagnosed and treated by this approach.Ĭancer has become a disease of significant concern in recent years due to its threat to human life, causing millions of deaths. For example, in antimicrobial treatments, light stimulation of an agent promotes the inactivation of bacteria, protozoa, viruses, and fungi. Phototherapy is a non-traditional strategy that has been used within several bio-applications.
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