Interaction of Genetically Encoded Photosensitizers with Scintillating Nanoparticles for X-ray Activated Photodynamic Therapy

Abstract

Photodynamic therapy (PDT) applications are limited by the low penetration of UV−visible light into biological tissues. Considering Xrays as an alternative to excite photosensitizers (PS) in a deeper tumor, an intermediate particle able to convert the X-ray energy into visible light (scintillating nanoparticle, ScNP) is necessary. Moreover, accumulation of PS in the target cells is also required. Genetically encoded proteins could be used as a photosensitizer, allowing the exclusive expression of PS inside the tumor cells. Here, the interaction of eGFP, KillerOrange, and KillerRed proteins with LaF 3 :Tb 3+ ScNP was investigated, for the first time, in terms of its physicochemical and energy transfer properties. The protein structure, stability, and function were evaluated upon adverse physiological conditions and X-ray irradiation. Optimal parameters for energy transfer from ScNP to the proteins were investigated, paving the way for the use of genetically encoded photosensitizers for applications in X-ray activated photodynamic therapy.

Microfluidic Synthesis of Theranostic Nanoparticles with Near-Infrared Scintillation: Toward Next-Generation Dosimetry in X-ray-Induced Photodynamic Therapy

“…56 The bacterial growth curves can be divided into four stages: (i) the lag phase, preceding the growth; (ii) the log phase, characterized by cell division and bacterial growth; (iii) the stationary phase, when growth is environmentally limited; and (iv) the death phase. 57 For the nonirradiated cultures, the control culture (without ScNPs), the culture with GdF 3 :Eu, and the culture with GdF@4MB presented the same E. coli growth profiles. That is evidenced in Figure 6a with a lag phase (i) in the initial 30 min and a log phase (ii) from 30 min up to 7 h, followed by the stationary phase (iii) after 7 h. The death phase was not detected in the period adopted for this experiment.…”

“…coli, which is a Gram-negative bacteria able to live on surfaces for long periods and presents high resistance to several PS . The bacterial growth curves can be divided into four stages: (i) the lag phase, preceding the growth; (ii) the log phase, characterized by cell division and bacterial growth; (iii) the stationary phase, when growth is environmentally limited; and (iv) the death phase . For the nonirradiated cultures, the control culture (without ScNPs), the culture with GdF 3 :Eu, and the culture with GdF@4MB presented the same E.…”

Advanced Optogenetic-Based Biosensing and Related Biomaterials

“…Furthermore, exotic optogenetic actuators are also reported that include light-activated enzymes. Such an example is the photosensitive membrane protein, KillerRed [ 60 ] that acts as a photoinducer of reactive oxygen species to produce cytotoxicity and trigger cell degeneration and death and is fundamental for recent phototherapies [ 70 , 71 ].…”

Recent Advances in Bio‐Compatible Oxygen Singlet Generation and Its Tumor Treatment

“…Compared with traditional PSs, killer Red has the advantage that it can precisely damage any desired cell compartment and directly kill cells through expression in tumor cells and appropriate gene transduction. [323,324] Recently, Micheletto et al [325] designed a gene coding protein as a PSs. These new PSs can receive the energy transfer of scintillating nanoparticles, which paves the way for the application of PDT in deep tumors.…”