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.

Effect of Murine Nerve Growth Factor and Sodium Ganglioside on the Levels of NF-kB p56,TLR-4 and MyD88 in Hippocampus of Epileptic Rats

Objective:Epilepsy is a prevalent neurological condition,and NF-kB,TLR-4,and MyD88 are significant contributors to its development.Murine nerve growth factor(NGF)and monosialotetrahexosylganlioside sodium for injection(MSI)are essential neurotrophic medications,yet their regulatory mechanism in the pathogenesis of epilepsy remains uncertain.The aim of this research was to examine the impacts of NGF and MSI on nuclear factor-kB(NF-kB)p65,toll-like receptor 4(TLR-4),and myeloid differentiation primary response gene 88(MyD88)in order to clarify their mechanisms of action in the management of epilepsy.Methods:A total of 40 SD rats were randomly assigned to one of five groups:blank,model,NGF model,MSI model,and NGF+MSI model.Epileptic rat models were induced through intraperitoneal injection of lithium chloride and pilocarpine solution.The rats'body mass and behavioral traits were subsequently observed.The Western blotting technique was utilized to detect the levels of NF-kB p65,TLR-4,and MyD88.Results:The findings indicated a more pronounced increase in body mass among the four groups prior to sacrifice,as compared to the model group.Notably,the NGF+MSI model group exhibited significant enhancements in food intake,activity,and body weight.The frequency of seizures in NGF group,MSI group,and NGF+MSI group were(5.33±1.15),(4.33±1.03),and(2.66±1.33)times/7 d,respectively,with neuronal apoptosis rates being(23.17±2.91),(21.38±3.07),(18.19±2.14)%times/7 d,respectively,which were lower than those in the model group.The levels of NF-kB p56,TLR-4,and MyD88 in the hippocampus were reduced in the model group compared to the three treatment groups.Furthermore,the expression levels in the NGF+MSI model group closely resembled those in the control group(P>0.05).Conclusion:Thorough examination revealed that NGF and MSI,either individually or in conjunction,were capable of suppressing the activation of the NF-kB pathway and enhancing the TLR-4/MyD88 signaling pathway to exert an antiepileptic influence.Furthermore,the combined administration of NGF and MSI demonstrated greater efficacy in safeguarding hippocampal neurons in epileptic rats.