Topical Delivery of Levocarnitine to the Cornea and Anterior Eye by Thermosensitive in-situ Gel for Dry Eye Disease

Figures & data

Table 1 Mathematical Model Fitting Results of LCTG

Model Equations	LCTG
Zero order	F=0.4905 t + 23.998 (r = 0.9353)
First order	ln (100-F)=-0.0236 t + 4.8935 (r = 0.9918)
Higuchi	F=8.6887 t^1/2 - 8.8348 (r = 0.9833)
Ritger-Peppas	lnF=0.6919 lnt + 1.1938 (r = 0.9837)

Figure 1 The photo of LCTG before and after gelation.

Figure 2 Cumulative release-time curve of LCTG (n = 5, $\overline{X}$± s).

Table 2 The Comprehensive Scoring Results of Eye Irritation Response

The group	Number	Observation Time
		0 d	1 d	2 d	3 d	4 d	5 d	6 d	7 d	1 h	2 h	4 h	24 h	48 h	72 h
Gel group	1	0	0	0	0	1	1	1	0	0	0	0	0	1	1
	2	0	0	0	0	0	0	1	1	0	0	1	0	0	0
	3	0	0	1	0	1	0	0	0	0	0	0	0	0	1
	4	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Control group	1	0	0	0	0	0	0	1	0	0	0	0	0	0	0
	2	0	0	0	0	0	0	0	0	0	1	0	0	0	0
	3	0	0	0	0	1	1	0	0	0	1	0	0	1	1
	4	0	1	0	0	1	0	1	0	0	0	0	0	0	0

Figure 3 The representative result of Draize test on 7th day (A:the gel group, B:the control group).

Figure 4 The representative result of FLS test on 7th day (A:the gel group, B:the control group).

Figure 5 The corneal topographic changes (A:The gel group, B:the control group).

Figure 6 The FLS staining results of groups (A:the normal group, B:the model group).

Table 3 The Quantity of Tear Fluid of Groups (Mm, n = 12, $\overline{X}$ ± s)

Time	Normal Group	Model Group	Solution Group	Gel Group
3d	6.73 ± 0.83	4.84 ± 0.73	5.10 ± 0.52	6.43 ± 0.63
7d	6.90 ± 0.56	6.03 ± 0.90	7.35 ± 0.50	7.79 ± 0.49

Figure 7 The quantity of tear fluid of groups (n = 12, $\overline{X}$ ± s). (N: the normal group; (M) the model group; (S) the solution group; (G) the gel group. Compare with (N)***P < 0.001, **P < 0.01; Compare with (M)^###P < 0.001; Compare with (S)⁺⁺⁺P < 0.001.).

Table 4 The Consequence Score of Corneal FLS Staining (n = 12, $\overline{X}$ ± s)

Time	Normal Group	Model Group	Solution Group	Gel Group
3 d	0.42 (0 ~ 1)	3.75 (1 ~ 6)	2.58 (0 ~ 5)	1.67 (0 ~ 4)
7 d	1.17 (0 ~ 2)	2.33 (1 ~ 5)	1.92 (1 ~ 3)	1.42 (0 ~ 2)

Figure 8 The FLS staining condition of groups (N: the normal group; (M) the model group; (S) the solution group; G: the gel group.).

Figure 9 The consequence score of corneal FLS staining (n = 12, x ± s). (N:the normal group; (M) the model group; (S) the solution group; (G) the gel group.Compare with (N)***P < 0.001, **P < 0.01; Compare with (M)^#P < 0.05).

Figure 10 The form of lacrimal gland (N:the normal group; (M) the model group; (S) the solution group; (G) the gel group.).

Table 5 Measurement Results of Central Corneal Epithelial Layer Thickness (μm, n = 5, $\overline{X}$ ± s)

Time	Normal	Model	Solution	Gel
3 d	38.66 ± 3.07	32.17 ± 2.67	34.95 ± 3.72	38.59 ± 3.44
7 d	38.90 ± 2.67	32.91 ± 3.00	38.02 ± 4.23	39.25 ± 2.65

Figure 11 The form of cornea (N:the normal group; (M) the model group; (S) the solution group; (G) the gel group. The area marked by yellow line segment represented corneal epithelium layer.

Figure 12 Measurement results of central corneal epithelial layer thickness (μm, n = 5, x ± s. (N) the normal group; (M) the model group; (S) the solution group; (G) the gel group. Compared with (N)*P < 0.05; Compared with (M) ^#P < 0.05).

Table 6 The Apoptosis Rate of Corneal Epithelial Cells (%, n = 3, $\overline{X}$ ± s)

Time	Normal	Model	Solution	Gel
3 d	1.98 ± 1.05	70.93 ± 7.20	57.12 ± 14.51	44.18 ± 5.71
7 d	1.60 ± 1.47	2.75 ± 1.66	2.48 ± 2.67	1.80 ± 1.56

Figure 13 The apoptosis rate of corneal epithelial cells after 3 days of the administrations (N: the normal group; (M) the model group; (S) the solution group; (G) the gel group. The green fluorescence indicated the nucleus of positive apoptotic cells while blue fluorescence represented the nucleus of other cells.).

Figure 14 The apoptosis rate of corneal epithelial cells after 7 days of the administrations (N: the normal group; (M) the model group; (S) the solution group; (G) the gel group. The green fluorescence indicated the nucleus of positive apoptotic cells while blue fluorescence represented the nucleus of other cells.).

Figure 15 The apoptosis rate of corneal epithelial cells (n = 3, $\overline{X}$ ± s. (N) the normal group; (M) the model group; (S) the solution group; (G) the gel group. Compared with (N)***P < 0.001, **P < 0.01; Compared with (M)^#P < 0.05.).

Figure 16 The expression of MMP-3 and MMP-9 in corneal epithelial cells (N: the normal group; (M) the model group; (S) the solution group; (G) the gel group. The blue fluorescence represented the nucleus.).

Figure 17 The conjunctival goblet cells after 7 days of the administrations (N: the normal group; (M) the model group; (S) the solution group; (G) the gel group. The blue arrows pointed to the conjunctival goblet cells.