Lactoferrin liposomal eyedrops: physicochemical characterization, cytotoxicity and ocular tolerance

Abstract

Purpose : LTF Lactoferrin (LTF), an ocular antimicrobial, immunomodulatory and anti-inflammatory protein has been encapsulated into liposomes to be applied as eyedrops. Physicochemical characterization, safety and ocular delivery had been assessed.

Methods : Average size and polydispersity index were assessed using Malvern zeta-sizer. Moreover, osmolality values were also assessed in an osmometer. To determine cell viability of LTF and LTF liposomes, human corneal epithelial cells (HCE-2) were used and the MTT test was carried out assessing several dilutions. In vitro ocular tolerance was carried oud by using fertilized chicken eggs purchased from G.A.L.L.S.A (Tarragona, Spain) and the HET-CAM-TBS assessment was carried out. In addition, using albino New Zealand rabbit’s ocular tolerance was also assessed in vivo by applying LTF liposomes as eyedrops for 3 days and observing the ocular surface to detect any possible irritation phenomena.

Results : LTF liposomes showed an average size below 100 nm and a monomodal population. Osmolality values confirm their suitability for ocular delivery. Cell viability carried out with corneal cells confirmed that all the concentrations employed were safe without causing any cytotoxicity (>80 % cell viability) (Figure 1). In addition, HET-CAM TBS confirmed that LTF liposomes did not cause ocular irritation and further in vivo ocular assays also confirmed that no irritation was observed

Conclusions : LTF liposomes accomplish suitable physicochemical properties to be administered for topical ocular delivery. In addition, they are not cytotoxic in corneal cells and did not cause ocular irritation. Clinical studies will confirm the safety and effectiveness of eye drops based on liposomal Lactoferrin.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Cell viability of Free LTF and LTF liposomes (HCE-2 cells)