Chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor for neurotrophic keratopathy

Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.

Capacity of human umbilical cord-derived mesenchymal stem cells to differentiate into sweat gland-like cells:a preclinical study

Human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)possess various advantageous properties,including self-renewal,extended proliferation potential,multi-lineage differentiation potential and capacity for differentiating into sweat gland-like cells in certain conditions.However,little is known about the effect of clinical-grade culture conditions on these properties and on the differentiative potential of hUC-MSCs.In this study,we sought to investigate the properties of hUC-MSCs expanded with animal serum free culture media(ASFCM)in order to determine their potential for differentiation into sweat gland-like cells.We found that primary cultures of hUC-MSCs could be established with ASFCM.Moreover,cells cultured in ASFCM showed vigorous proliferation comparable to those of cells grown in classical culture conditions containing fetal bovine serum(FBS).Morphology of hUC-MSCs cultured in ASFCM was comparable to those of cells grown under classical culture conditions,and hUC-MSCs grown in both of the two culture conditions tested showed the typical antigen profile of MSCs—positive for CD29,CD44,CD90,and CD105,and negative for CD34 and CD45,as expected.Chromosomal aberration assay revealed that the cells were stable after long-term culture under both culture conditions.Like normal cultured MSCs,hUC-MSCs induced under ASFCM conditions exhibited expression of the same markers(CEA,CK14 and CK19)and developmental genes(EDA and EDAR)that are characteristic of normal sweat gland cells.Taken together,our findings indicate that the classical culture medium used to differentiate hUC-MSCs into sweat gland-like cells can be replaced safely by ASFCM for clinical purposes.