Can nanotechnology potentiate photodynamic therapy?

Abstract

Photodynamic therapy (PDT) uses the combination of nontoxic dyes and harmless visible light to produce reactive oxygen species that can kill cancer cells and infectious microorganisms. Due to the tendency of most photosensitizers (PS) to be poorly soluble and to form nonphotoactive aggregates, drug-delivery vehicles have become of high importance. The nanotechnology revolution has provided many examples of nanoscale drug-delivery platforms that have been applied to PDT. These include liposomes, lipoplexes, nanoemulsions, micelles, polymer nanoparticles (degradable and nondegradable), and silica nanoparticles. In some cases (fullerenes and quantum dots), the actual nanoparticle itself is the PS. Targeting ligands such as antibodies and peptides can be used to increase specifi city. Gold and silver nanoparticles can provide plasmonic enhancement of PDT. Two-photon excitation or optical upconversion can be used instead of one-photon excitation to increase tissue penetration at longer wavelengths. Finally, after sections on in vivo studies and nanotoxicology, we attempt to answer the title question, " can nanotechnology potentiate PDT ? "

Photodynamic therapy, priming and optical imaging: Potential co-conspirators in treatment design and optimization — a Thomas Dougherty Award for Excellence in PDT paper

“…Moreover, formulating PSs through nanoconstructs also addresses several challenges related to the physiochemical properties of PSs, their systemic distribution, low selectivity, and certain TME factors such as low oxygenation [276][277][278]. A wide variety of nanocarriers such as liposomes, polymeric micelles, polymeric nanoparticles, and inorganic nanoparticles have been investigated for the encapsulation of hydrophobic and hydrophilic PSs in an attempt to enhance their delivery to the disease site [279,280]. These formulations rely on the passive accumulation in the tumor through the EPR effect [281] and degrade at desired sites thus allowing for PS release.…”

Susceptibility and Resistance Mechanisms During Photodynamic Therapy of Melanoma

“…Rationally designed DNA nanosponges were reported to load and deliver PSs effectively, target tumors precisely, and effectively relieve hypoxia-associated resistance to enhance the efficacy of PDT (168). In general, the application of nanotechnology in PDT aims to improve water hydrophobic drug compatibility/PS, protect against drug degradation, produce a sustained release of drugs, improve drug bioavailability (169), increase tumor selectivity, and allow improved treatment of deep tumor infiltration depth, so as to increase therapeutic efficacy and reduce adverse side effects (170)(171)(172).…”

Porphyrin‐Based Metal−Organic Framework Compounds as Promising Nanomedicines in Photodynamic Therapy

“…[1] Photodynamic therapy (PDT) is a new therapy that has been applied to tumour treatment in the late 1970s. [2,3] PDT has developed particularly rapidly in recent decades and has been successfully employed in the treatment of a variety of malignant tumours and has achieved excellent results. [4,5] Compared with traditional tumour treatment methods, PDT has the characteristics of small toxic and side effects and noninvasiveness.…”