PLoS ONE (Jan 2015)

Ocular Inserts for Sustained Release of the Angiotensin-Converting Enzyme 2 Activator, Diminazene Aceturate, to Treat Glaucoma in Rats.

  • Giselle Foureaux,
  • Juçara Ribeiro Franca,
  • José Carlos Nogueira,
  • Gustavo de Oliveira Fulgêncio,
  • Tatiana Gomes Ribeiro,
  • Rachel Oliveira Castilho,
  • Maria Irene Yoshida,
  • Leonardo Lima Fuscaldi,
  • Simone Odília Antunes Fernandes,
  • Valbert Nascimento Cardoso,
  • Sebastião Cronemberger,
  • André Augusto Gomes Faraco,
  • Anderson José Ferreira

DOI
https://doi.org/10.1371/journal.pone.0133149
Journal volume & issue
Vol. 10, no. 7
p. e0133149

Abstract

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The aim of this study was to develop and evaluate the effects of chitosan inserts for sustained release of the angiotensin-converting enzyme 2 (ACE2) activator, diminazene aceturate (DIZE), in experimental glaucoma. Monolayer DIZE loaded inserts (D+I) were prepared and characterized through swelling, attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and in vitro drug release. Functionally, the effects of D+I were tested in glaucomatous rats. Glaucoma was induced by weekly injections of hyaluronic acid (HA) into the anterior chamber and intraocular pressure (IOP) measurements were performed. Retinal ganglion cells (RGC) and optic nerve head cupping were evaluated in histological sections. Biodistribution of the drug was accessed by scintigraphic images and ex vivo radiation counting. We found that DIZE increased the swelling index of the inserts. Also, it was molecularly dispersed and interspersed in the polymeric matrix as a freebase. DIZE did not lose its chemical integrity and activity when loaded in the inserts. The functional evaluation demonstrated that D+I decreased the IOP and maintained the IOP lowered for up to one month (last week: 11.0 ± 0.7 mmHg). This effect of D+I prevented the loss of RGC and degeneration of the optic nerve. No toxic effects in the eyes related to application of the inserts were observed. Moreover, biodistribution studies showed that D+I prolonged the retention of DIZE in the corneal site. We concluded that D+I provided sustained DIZE delivery in vivo, thereby evidencing the potential application of polymeric-based DIZE inserts for glaucoma management.