title: Intravitreal silicon-based quantum dots as neuroprotective factors in a model of retinal photoreceptor degeneration.
abstract: OBJECTIVE
  To study the intravitreal application of silicon quantum dots (QDs) and their capabilities to deliver electrical stimulation to the retinal cells and to assess the potential effect on retinal electrophysiology and anatomy.
  
  
  METHODS
  A Royal College of Surgeon rat model of retinal degeneration was used in this study. A total of 32 eyes were used, divided in four groups of 8 eyes each; the first group received the silicon-based QD, the second group received an inactive gold-based QD, the third group received a sham injection, and the fourth group was used as a control. An electroretinogram (ERG) was done at baseline and thereafter every week for 9 weeks. At the end of the follow-up, eyes were collected for further pathologic analysis and nuclei cell counts.
  
  
  RESULTS
  Eyes within the silicon-based QD group showed a definite but transient increase in the waves of the ERG, especially in the rod response compared with the sham and control groups (P < 0.05). The pathologic examination demonstrated a higher nuclei count in the QD group, consistent with a higher cell survival rate than that in the sham and control groups in which cells degenerated as expected.
  
  
  CONCLUSIONS
  Intravitreal injection of silicon-based QD seems to be safe and well tolerated, with no evident toxic reaction and demonstrates a beneficial effect by prolonging cell survival rate and improving ERG patterns in a well-established model of retinal degeneration. (ClinicalTrials.gov numbers NCT00407602, NCT01490827.).
authors: Department of Ophthalmology, University of Colorado Health and Science Center, Rocky Mountain Lions Eye Institute, University of Colorado School of Medicine, Aurora, Colorado, USA. jeffrey.olson@ucdenver.edu
authors: Jeffrey L
authors: JL
authors: Olson
authors: Raul
authors: R
authors: Velez-Montoya
authors: Naresh
authors: N
authors: Mandava
authors: Conrad R
authors: CR
authors: Stoldt
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D002452:Cell Count; D002470:Cell Survival / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D004596:Electroretinography; D005260:Female; D006046:Gold; D058449:Intravitreal Injections; D008297:Male; D045663:Quantum Dots; D051381:Rats; D011922:Rats, Mutant Strains; D012160:Retina / Q000166:cytology / Q000502:physiology*; D012162:Retinal Degeneration / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000502:physiology; D012825:Silicon
chemical_list: D006046:Gold; D012825:Silicon