title: Titania coated upconversion nanoparticles for near-infrared light triggered photodynamic therapy.
abstract: Because of the limited penetration depth of visible light that generally excites most of the available photosensitizers (PSs), conventional photodynamic therapy (PDT) is limited to the treatment of superficial and flat lesions. Recently, the application of deep penetrating near-infrared (NIR) light excitable upconversion nanoparticles (UCNs) in conjunction with PDT has shown to have clear potential in the treatment of solid tumors due to its ability to penetrate thick tissue. However, various constructs developed so far have certain limitations such as poor or unstable PS loading, reducing their therapeutic efficacy and limiting their application to solution or cell-based studies. In this work, we present a method to fabricate uniform core-shell structured nanoconstruct with a thin layer of photocatalyst or PS-titanium dioxide (TiO2) stably coated on individual UCN core. Our design allows controllable and highly reproducible PS loading, preventing any leakage of PS compared to previously developed nanoconstructs, thus ensuring repeatable PDT results. Further surface modification of the developed nanoconstructs with polyethylene glycol (PEG) rendered them biocompatible, demonstrating good therapeutic efficacy both in vitro and in vivo.
authors.affiliation: NUS Graduate School for Integrative Sciences & Engineering (NGS) , Singapore 117456.
authors.forename: Sasidharan Swarnalatha
authors.initials: SS
authors.lastname: Lucky
authors.forename: Niagara
authors.initials: N
authors.lastname: Muhammad Idris
authors.forename: Zhengquan
authors.initials: Z
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Huang
authors.forename: Khee Chee
authors.initials: KC
authors.lastname: Soo
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D003624:Darkness; D005260:Female; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007259:Infrared Rays; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D009062:Mouth Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology; D050997:Nanomedicine / Q000379:methods*; D053758:Nanoparticles; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology / Q000633:toxicity; D011092:Polyethylene Glycols / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D011092:Polyethylene Glycols; D014025:Titanium
keywords: cancer; near-infrared; photodynamic therapy; titanium dioxide; upconversion nanoparticles