title: Photocleavable Hydrogel-Coated Upconverting Nanoparticles: A Multifunctional Theranostic Platform for NIR Imaging and On-Demand Macromolecular Delivery.
abstract: Lanthanide-doped upconverting nanoparticles (UCNPs) have emerged as excellent nanotransducers for converting longer wavelength near-infrared (NIR) light to shorter wavelengths spanning the ultraviolet (UV) to the visible (Vis) regions of the spectrum via a multiphoton absorption process, known as upconversion. Here, we report the development of NIR to UV-Vis-NIR UCNPs consisting of LiYF4:Yb(3+)/Tm(3+)@SiO2 individually coated with a 10 ± 2 nm layer of chitosan (CH) hydrogel cross-linked with a photocleavable cross-linker (PhL). We encapsulated fluorescent-bovine serum albumin (FITC-BSA) inside the gel. Under 980 nm excitation, the upconverted UV emission cleaves the PhL cross-links and instantaneously liberates the FITC-BSA under 2 cm thick tissue. The release is immediately arrested if the excitation source is switched off. The upconverted NIR light allows for the tracking of particles under the tissue. Nucleus pulposus (NP) cells cultured with UCNPs are viable both in the presence and in the absence of laser irradiation. Controlled drug delivery of large biomolecules and deep tissue imaging make this system an excellent theranostic platform for tissue engineering, biomapping, and cellular imaging applications.
authors.affiliation: Department of Mining and Materials Engineering, McGill University , Montreal, QC H3A 0C5, Canada.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Jalani
authors.affiliation: Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec , Varennes, QC J3X 1S2, Canada.
authors.forename: Rafik
authors.initials: R
authors.lastname: Naccache
authors.affiliation: Department of Surgery, McGill University , Montreal, QC H3G 1A4, Canada.
authors.forename: Derek H
authors.initials: DH
authors.lastname: Rosenzweig
authors.affiliation: Department of Surgery, McGill University , Montreal, QC H3G 1A4, Canada.
authors.forename: Lisbet
authors.initials: L
authors.lastname: Haglund
authors.affiliation: Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec , Varennes, QC J3X 1S2, Canada.
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Vetrone
authors.affiliation: Department of Mining and Materials Engineering, McGill University , Montreal, QC H3A 0C5, Canada.
authors.forename: Marta
authors.initials: M
authors.lastname: Cerruti
mesh_terms: D000818:Animals; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D016503:Drug Delivery Systems; D005453:Fluorescence; D005459:Fluorides / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D007259:Infrared Rays; D008094:Lithium / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010782:Photolysis; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013667:Technetium / Q000737:chemistry; D000068936:Theranostic Nanomedicine; D015019:Yttrium / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D012710:Serum Albumin, Bovine; D015019:Yttrium; D013667:Technetium; D012822:Silicon Dioxide; D048271:Chitosan; D008094:Lithium; D005459:Fluorides