Application of Encapsulated Cell Technology for Treating Ophthalmic Diseases
Neurotech USA, Vice President - Research and Development
Purpose: To develop Encapsulated Cell Technology for the controlled, continuous, and long-term administration of protein drugs in the eye.
Method: Polymer membrane capsules (1.0 cm in length and 1.0 mm in diameter) were loaded with mammalian cells that were genetically engineered to secrete CNTF. The cell containing capsules were then surgically implanted into the posterior chamber of one eye of an rcd1 dog at 7 weeks of age, when retinal degeneration is in progression but not complete. The contralateral eyes were not treated. The capsules remained in the eyes for either 7 weeks or 14 weeks. At the end of the studies, the capsules were explanted and CNTF output and cell viability were evaluated. The eyes were processed for histologic evaluation. To evaluate the pharmacokinetics of long-term delivery of CNTF, the CNTF secreting devices were implanted into the rabbit eyes and the device performance (CNTF output and vitreous CNTF levels) was followed for up to a year.
Results: In the rcd1 dogs, the number of outer nuclei layers (ONL) of photoreceptors was significantly higher in the eye that received a CNTF-secreting implant than the untreated contralateral eye. No adverse effects to the retina in the treated eyes were observed. Furthermore, the long-term pharmacokinetics study demonstrated consistent CNTF delivery in the rabbit eyes for at least one year.
Conclusions: CNTF delivered by encapsulated c
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