Hitherto‐Unexplored Photodynamic Therapy of Ag₂S and Enhanced Regulation Based on Polydopamine In Vitro and Vivo

Abstract

Given their superior penetration depths, photosensitizers with longer absorption wavelengths present broader application prospects in photodynamic therapy (PDT). Herein, Ag2S quantum dots were discovered, for the first time, to be capable of killing tumor cells through the photodynamic route by near‐infrared light irradiation, which means relatively less excitation of the probe compared with traditional photosensitizers absorbing short wavelengths. On modification with polydopamine (PDA), PDA‐Ag2S was obtained, which showed outstanding capacity for inducing reactive oxygen species (increased by 1.69 times). With the addition of PDA, Ag2S had more opportunities to react with surrounding O2, which was demonstrated by typical triplet electron spin resonance (ESR) analysis. Furthermore, the PDT effects of Ag2S and PDA‐Ag2S achieved at longer wavelengths were almost identical to the effects produced at 660 nm, which was proved by studies in vitro. PDA‐Ag2S showed distinctly better therapeutic effects than Ag2S in experiments in vivo, which further validated the enhanced regulatory effect of PDA. Altogether, a new photosensitizer with longer absorption wavelength was developed by using the hitherto‐unexplored photodynamic function of Ag2S quantum dots, which extended and enhanced the regulatory effect originating from PDA.

A Multiparametric Evaluation of Quantum Dot Size and Surface-Grafted Peptide Density on Cellular Uptake and Cytotoxicity

“…8,9 Secondly, their high intensity and resistance towards photobleaching permit the longterm tracking of live, single-molecules, which offers detailed information on intracellular trafficking and processing. 10,11 QDs are also being extensively used in the development of anticancer interventions either directly for photodynamic [12][13][14][15] or photothermal [16][17][18] therapy applications, or in combination with existing drug formulations, 5,19,20 rendering them as promising theranostic agents.…”

Synthesis and Bioapplications of Ag2S Quantum Dots with Near‐Infrared Fluorescence

“…synthesized polydopamine (PDA)‐functionalized Ag 2 S QDs for fluorescence imaging‐guided PDT of tumors ( Figure a). [ 77 ] As shown in Figure 16b, PDT with the designed nanotheranostic was more effective than unfunctionalized nanoparticles. Li et al.…”

“…Reproduced with permission. [ 77 ] Copyright 2019, Wiley‐VCH. c) Schematic illustration and d) SDT efficacy of (QD@P)Rs.…”

Recent progress in sono-photodynamic cancer therapy: From developed new sensitizers to nanotechnology-based efficacy-enhancing strategies

“…The chemical structures of organic sensitizers and schematic illustration of inorganic and hybrid sensitizers used in cancer therapy are shown in Figure 2 , Figure 3 . The characteristic parameters of the sensitizers used in different tumor cells or animal models are summarized in Table 1 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 .

Figure 2 The chemical structures of organic sensitizers used in cancer therapy.

…”

“…Semiconductor QDs have attracted increasing attention due to tunable band gaps, high molar extinction coefficients, sufficient photostability, and the ability to generate multiple electron–hole pairs 129 . Ag 2 S QDs could be used as either sonosensitizer or photosensitizer to generate ROS for PDT and SDT 61 , 62 . Biocompatible Ag 2 S QDs prepared using high-temperature pyrolysis method were modified with PEGylated phospholipids to form nanoparticles, which had photodynamic behavior under 808 nm NIR irradiation.…”