Photodynamic Therapy—An Up-to-Date Review

Abstract

The healing power of light has attracted interest for thousands of years. Scientific discoveries and technological advancements in the field have eventually led to the emergence of photodynamic therapy, which soon became a promising approach in treating a broad range of diseases. Based on the interaction between light, molecular oxygen, and various photosensitizers, photodynamic therapy represents a non-invasive, non-toxic, repeatable procedure for tumor treatment, wound healing, and pathogens inactivation. However, classic photosensitizing compounds impose limitations on their clinical applications. Aiming to overcome these drawbacks, nanotechnology came as a solution for improving targeting efficiency, release control, and solubility of traditional photosensitizers. This paper proposes a comprehensive path, starting with the photodynamic therapy mechanism, evolution over the years, integration of nanotechnology, and ending with a detailed review of the most important applications of this therapeutic approach.

Latest Innovations and Nanotechnologies with Curcumin as a Nature-Inspired Photosensitizer Applied in the Photodynamic Therapy of Cancer

“…the first generation (HpD and Photofrin) had poor absorption in the red visible range, limited applications and an unpleasant side effect, the residual sensitivity of the skin; -the second generation (see some examples depicted in Figure 2) allowed a much more accelerated development of PDT (5-Aminolaevulinic acid (ALA); Benzoporphyrin derivative monoacid ring A (BPD-MA) or Verteporfin; Chlorins sold as Purlytin; Tetra(m-hydroxyphenyl)chlorin (mTHPC) or Foscan; Lutetium texaphyrin with tradename Lutex or Lutrin; 9-Acetoxy-2,7,12,17-tetrakis-(β-methoxyethyl)-porphycene or ATMPn; Zinc phthalocyanine (CGP55847); Naphthalocyanines (NCs) and Porphyrin-type Chromophores (PC) with modified marginal operation by different functional groups, such as nitrophenyl, aminophenyl, hydroxyphenyl, pyridiniumyl derivatives etc. [7,[27][28][29]. Third generation PSs include antibody-directed photosensitizers, such as, for example, the monoclonal antibodies for rising specificity and enhanced capacity of action, better pharmacokinetics, improved function, selective targeted and delivery etc., and support the hope for a future better featured PDT [28,30].…”

“…[7,[27][28][29]. Third generation PSs include antibody-directed photosensitizers, such as, for example, the monoclonal antibodies for rising specificity and enhanced capacity of action, better pharmacokinetics, improved function, selective targeted and delivery etc., and support the hope for a future better featured PDT [28,30].…”

The Nanosystems Involved in Treating Lung Cancer

“…Firstly, gold nanomaterials can be used as a diagnostic tool, offering important advantages in comparison with traditional organic dyes, such as a minimal toxicity and insignificant quenching [146]. Finally, gold nanomaterials exhibit therapeutic effects per se due to their implications and use in Photodynamic therapies (PDTs), which have been studied extensively in the chapter on the therapeutic effects of nanomaterials in the current article [147].…”

Recent Advances on Stimuli-Responsive Hydrogels Based on Tissue-Derived ECMs and Their Components: Towards Improving Functionality for Tissue Engineering and Controlled Drug Delivery

“…As NIR laser irradiation is undoubtedly the most extensively studied light stimulus for controlled drug delivery on ECM-based hydrogels, a broad variety of release mechanisms triggered by this stimulus have been considered in several pharmacological applications. NIR-triggered photodynamic therapy (PDT), a process in which cell death is induced by an increase in ROS generation with the activation of a photosensitizer, is one of the emerging anticancer therapies with the highest potential for clinical translation [149]. This is as, through this approach, it is possible to simultaneously harness the controlled activation of anticancer drugs and their release rates from the hydrogel matrix.…”