A functional bimodal mesoporous silica nanoparticle with redox/cellulase dual-responsive gatekeepers for controlled release of fungicide.

Integrating toxic fungicide into a functional stimuli-responsive nanosystem can effectively improve the fungus control specificity and reduce the effect on non-target organisms. We report here a redox and cellulase dual-responsive multifunctional nanoparticle based on bimodal mesoporous silica (BMMs) to deliver prochloraz (Pro) for the smart management of wilt disease (Pro-AC-SS-BMMs, known as P-ASB). The surface of the nanocarrier was modified with an aminosilane coupling agent, and Pro was encapsulated by physical adsorption using 2,2'-dithiodiacetic acid as a smart bridge and disulfide (SS) cross-linked aminocellulose (AC) as gatekeepers. P-ASB nanoparticles (NPs) had a spherical structure, and the size was 531.2 ± 4.9 nm. The loading rate of Pro was 28.5%, and the NPs possessed excellent redox/cellulase dual-responsive release characteristics in the presence of glutathione (GSH) and cellulase. The nanocarrier could effectively protect Pro against photodegradation and had better foliar wettability than the Pro technical. Fluorescence tracer results showed that the nanocarriers were taken up and activated by the mycelium. P-ASB NPs had better control efficacy against Rhizoctonia solani and had no significant toxicity to cells and bacteria. This study provides a new strategy for enhancing the environmental protection and promoting the development of green agriculture.

pH and Redox Dual-Responsive Mesoporous Silica Nanoparticle as Nanovehicle for Improving Fungicidal Efficiency.

Prochloraz (Pro) controlled-release nanoparticles (NPs) based on bimodal mesoporous silica (BMMs) with redox and pH dual responses were successfully prepared in this study. BMMs was modified by a silane coupling agent containing a disulfide bond, and ß-cyclodextrin (ß-CD) was grafted on the surface of the NPs through host-guest interaction. Pro was encapsulated into the pores of nanoparticles by physical adsorption. NPs had a spherical structure, and their average diameter was 546.4 ± 3.0 nm as measured by dynamic light scattering. The loading rate of Pro was 28.3%, and it achieved excellent pH/redox dual-responsive release performance under acidic conditions. Foliage adhesion tests on tomato leaves showed that the NPs had good adhesion properties compared to the commercial formulation. Owing to the protection of the nanocarrier, NPs became more stable under ultraviolet light and high temperature, which improves the efficient utilization of Pro. Biological activity tests showed that the NPs exhibited effective antifungal activity, and the benign biosafety of the nanocarrier was also observed through toxicology tests on cell viability and the growth of Escherichiacoli (E. coli). This work provides a promising approach to improving the efficient utilization of pesticides and reducing environmental pollution.

A pH Dual-Responsive Multifunctional Nanoparticle Based on Mesoporous Silica with Metal-Polymethacrylic Acid Gatekeeper for Improving Plant Protection and Nutrition.

Integrating pesticides and mineral elements into a multi-functional stimuli-responsive nanocarrier can have a synergistic effect on protecting plants from pesticides and the supply of nutrients. Herein, a pH dual-responsive multifunctional nanosystem regulated by coordination bonding using bimodal mesoporous silica (BMMs) as a carrier and coordination complexes of ferric ion and polymethacrylic acid (PMAA/Fe3+) as the gatekeeper was constructed to deliver prochloraz (Pro) for the smart treatment of wilt disease (Pro@BMMs-PMAA/Fe3+). The loading capacity of Pro@BMMs-PMAA/Fe3+ nanoparticles (Nps) was 24.0% and the "PMMA/Fe3+" complexes deposited on the BMMs surface could effectively protect Pro against photodegradation. The nanoparticles possessed an excellent pH dual-responsive release behavior and better inhibition efficacy against Rhizoctonia solani. Fluorescence tracking experiments showed that Nps could be taken up and transported in fungi and plants, implying that non-systemic pesticides could be successfully delivered into target organisms. Furthermore, BMMS-PMAA/Fe3+ nanocarriers could effectively promote the growth of crop seedlings and had no obvious toxicological influence on the cell viability and the growth of bacteria. This study provides a novel strategy for enhancing plant protection against diseases and reducing the risk to the environment.

Visual Acuity and Size of Choroidal Neovascularization in Highly Myopic Eyes with a Dome-Shaped Macula.

INTRODUCTION: A dome-shaped macula (DSM) is an inward convexity or anterior deviation of the macular area. DSM is believed as a protective factor in maintaining visual acuity in highly myopic eyes. OBJECTIVE: To investigate the correlation between best-corrected visual acuity (BCVA), choroidal neovascularization (CNV), and a dome-shaped macula (DSM) in highly myopic eyes. METHODS: In this retrospective and observational case series study, BCVA tests and optical coherence tomography (OCT) were performed in a total of 472 highly myopic eyes (refractive error ≥6.5 diopters or axial length ≥26.5 mm). CNV was detected by fundus fluorescein angiography (FFA), and the CNV area was measured by ImageJ software. BCVA, central retinal thickness (CRT), and the CNV area were compared between highly myopic eyes with and without DSM. RESULTS: The data revealed 13 eyes with DSM complicated by CNV, for an estimated prevalence of 25%. The eyes with CNV in the DSM group showed worse BCVA than those in the non-DSM group (1.59 ± 0.69 and 0.63 ± 0.64, respectively, p < 0.05), and the CNV area in the DSM group was larger than that in the non-DSM group (2793.91 ± 2181.24 and 1250.71 ± 1210.36 pixels, respectively, p < 0.05). After excluding the eyes with CNV, the DSM group had better BCVA than the non-DSM group (0.33 ± 0.17 and 0.44 ± 0.48, respectively, p < 0.05); however, no significant difference was observed in the CRT of eyes with CNV between the DSM group and the non-DSM group. CONCLUSION: These results show that DSM might be a protective mechanism for visual acuity, but its protective capability is limited. DSM eyes have better visual acuity within the protective capability. If a more powerful pathogenic factor exceeding the protective capability is present, then the eye will have more severe CNV and worse visual acuity.

Comparison of 0.025% FK-506, 0.05% Cyclosporin A, and 0.3% Sodium Hyaluronate Eye Drops for the Treatment of Botulinum Toxin B-Induced Mouse Dry Eye.

PURPOSE: To compare the effects of FK-506, cyclosporin A (CsA), and sodium hyaluronate (HA) eye drops for the treatment of botulinum toxin B (BTX-B)-induced mouse dry eye. METHODS: CBA/J mice were randomized into 5 groups. The groups received treatment with eye drops containing 0.025% FK-506 combined with 0.3% HA (FK-506+HA group), 0.025% FK-506 (FK-506 group), 0.05% CsA (CsA group), 0.3% HA (HA group), or 0.9% saline (saline group) 3 days after an intralacrimal gland injection with 20 mU of BTX-B. Tear production, corneal fluorescein staining, blink rate, and the mRNA and protein expression levels of inflammatory cytokines were measured. RESULTS: FK-506+HA eye drops increased tear production and reduced the corneal fluorescein staining scores at all time points after treatment compared with those in the saline group. Compared with those in the saline group, the tear production and severity of corneal epithelial defects in the FK-506 group were significantly improved at weeks 2 and 4. Compared with the saline eye drops, the CsA eye drops ameliorated only tear production and corneal fluorescein staining scores at week 4 after administration. The FK-506+HA, FK-506, and CsA eye drops downregulated the expression of inflammatory cytokines in both the keratoconjunctival tissues and lacrimal glands at week 4. CONCLUSIONS: The topical application of 0.025% FK-506 combined with 0.3% HA, 0.025% FK-506, or 0.05% CsA can suppress the expression of inflammatory cytokines and can alleviate the signs of dry eye. Topical application of 0.025% FK-506 combined with 0.3% HA showed the best therapeutic effect and may be a possible therapy for dry eye.

Associated factors, diagnosis and management of Acanthamoeba keratitis in a referral Center in Southern China.

BACKGROUND: To analyse the associated factors, diagnosis, clinical manifestations and therapeutic effects of Acanthamoeba keratitis at a tertiary ophthalmic centre in Southern China. METHODS: A retrospective clinical study was performed in fifteen patients who were admitted to Zhongshan Ophthalmic Centre (ZOC) from January 2004 to December 2014. The patients' pathogenesis-associated factors were analysed, and preoperative diagnoses were determined using corneal scraping cultures and/or confocal microscopy followed. All diagnoses were confirmed by postoperative pathological examinations. At follow-up, best-corrected visual acuity (BCVA), the recurrence rate and graft transparency were evaluated to assess therapeutic effects. RESULTS: The main pathogenic factors observed in the fifteen patients were a history of injury or a foreign body entering the eyes (12 cases). In all, Acanthamoeba keratitis was preoperatively diagnosed in 5 cases using corneal scraping cultures or confocal microscopy. Ocular symptoms included redness, photophobia, tearing, and blurred vision. Penetrating keratoplasty was performed in thirteen patients, and postoperative pathological examinations were performed to confirm these diagnoses. The logarithm of the minimum angle of resolution (logMAR) of visual acuity was significantly improved after keratoplasty (p < 0.01). No recurrence was observed, and approximately 90% of the corneal grafts were found to be transparent during the follow-up period. CONCLUSIONS: Corneal trauma may be the main pathogenic factor that causes Acanthamoeba keratitis in southern China. Corneal scraping combined with confocal microscopy was helpful for achieving a correct diagnosis. Early keratoplasty combined with amoebicidal therapy is an effective treatment strategy in Acanthamoeba keratitis.

Conjunctival Lymphangiogenesis Was Associated with the Degree of Aggression in Substantial Recurrent Pterygia.

Objective. To examine conjunctival lymphatic vessels and to analyze the relationship between lymphangiogenesis and aggressive recurrent pterygia. Methods. Tissues from 60 excised recurrent (including 19 of Grade 1, 28 of Grade 2, and 13 of Grade 3) pterygia were used in the study. Tissues from 9 nasal epibulbar conjunctivae segments were used as controls. Pterygium slices from each patient were immunostained with LYVE-1 monoclonal antibodies to identify lymphatic microvessels in order to calculate the lymphovascular area (LVA), the lymphatic microvessel density (LMD), and the lymphovascular luminal diameter (LVL). The relationship between lymphangiogenesis (LVA, LMD, and LVL) and pterygium aggression (width, extension, and area) was clarified. Results. Few LYVE-1 positive lymphatic vessels were found in the normal epibulbar conjunctiva segments. Lymphatic vessels were slightly increased in Grades 1 and 2 and were dramatically increased in Grade 3 recurrent pterygia. The LMD was correlated with the pterygium area in Grade 1 and 2 pterygia. In Grade 3, both LVA and LMD were significantly correlated with the pterygium area. Conclusions. Lymphangiogenesis was associated with the degree of aggression in recurrent pterygia, particularly in substantial Grade 3 recurrent pterygia.

Inhibition of TREM-1 and Dectin-1 Alleviates the Severity of Fungal Keratitis by Modulating Innate Immune Responses.

PURPOSE: To explore the possibility that inhibiting triggering receptor expressed on myeloid cells-1 (TREM-1) and Dendritic cell-associated C-type lectin-1(Dectin-1) could modulate the innate immune response and alleviate the severity of corneal fungal keratitis. METHOD: TREM-1 and Dectin-1 expression was detected in fungus-infected human corneal specimens by real-time PCR. C57BL/6 (B6) mice were injected with Aspergillus fumigatus and divided into 4 groups that received subconjunctival injections of PBS and IgG as a control (group I), mTREM-1/IgG fusion protein (group II), the soluble ß-glucan antagonist laminarin (group III), or mTREM-1/Fc and laminarin (group IV). Corneal virulence was evaluated based on clinical scores. TREM-1 and Dectin-1 mRNA levels were assayed using real-time PCR. The distribution patterns of TREM-1, Dectin-1 and cellular infiltrates in fungus-infected corneas were examined by immunohistochemistry. Moreover, changes in T Helper Type1 (Th1)-/ T Helper Type1 (Th2)- type cytokines and proinflammatory cytokines were measured. RESULTS: The expression of TREM-1 and Dectin-1 increased significantly and correlated positively with the progression of fungal keratitis. Most infiltrated cells were neutrophils and secondarily macrophages in infected cornea. The clinical scores decreased after interfering with TREM-1 and Dectin-1 expression in infected mouse corneas. Levels of Th1-type cytokines including interleukin-12 (IL-12), IL-18 and interferon-γ (IFN-γ) were decreased in the cornea, while the levels of Th2-type cytokines, including IL-4, IL-5 and IL-10, showed obvious increases. CONCLUSION: TREM-1 and Dectin-1 function concurrently in the corneal innate immune response by regulating inflammatory cytokine expression in fungal keratitis. Inhibition of TREM-1 and Dectin-1 can alleviate the severity of corneal damage by downregulating the excessive inflammatory response.

Tacrolimus (FK506) suppresses TREM-1 expression at an early but not at a late stage in a murine model of fungal keratitis.

PURPOSE: To investigate the efficacy and mechanism of tacrolimus(FK506), which is a novel macrolide immunosuppressant, in inhibiting triggering receptor expressed on myeloid cells-1 (TREM-1) expression in a murine keratitis model induced by Aspergillus fumigatus. METHOD: TREM-1 was detected in 11 fungus-infected human corneas by quantitative real-time PCR (qRT-PCR). RAW264.7 macrophages were divided into four groups, which received treatment with zymosan (100 µg/ml), zymosan (100 µg/ml) + mTREM-1/Fc protein (1 µg/ml), or zymosan (100 µg/ml) + FK506 (20 µM) or negative-control treatment. After this treatment, the expression of TREM-1, interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNFα) was assayed using qRT-PCR and ELISA. The mouse model of fungal keratitis was created by intrastromal injection with Aspergillus fumigatus, and the mice were divided into 2 groups: group A received vehicle eye drops 4 times each day, and group B received 4 doses of FK506 eye drops each day. Corneal damage was evaluated by clinical scoring and histologic examination,and myeloperoxidase (MPO) protein levels were also detected by ELISA. The expression of TREM-1, IL-1ß and TNFα was then determined at different time points using qRT-PCR and ELISA. RESULTS: TREM-1 expression dramatically increased in the human corneas with fungal keratitis. In contrast, FK506 reduced the expression of TREM-1, IL-1ß and TNFα in RAW264.7 macrophages stimulated with zymosan. In the mouse model, at day 1 post-infection, the corneal score of the FK506-treated group was lower than that of the control, and polymorphonuclear neutrophil (PMN) infiltration was diminished. TREM-1, IL-1ß and TNFα expression was significantly reduced at the same time point. However, the statistically significant differences in cytokine expression, clinical scores and infiltration disappeared at 5 days post-infection. CONCLUSIONS: FK506 may inhibit the inflammation induced by fungi and alleviate the severity of corneal damage at an early stage of fungal keratitis by downregulating TREM-1 expression.

Comparison of deep anterior lamellar keratoplasty and penetrating keratoplasty with respect to postoperative corneal sensitivity and tear film function.

PURPOSE: To investigate tear film function, central and peripheral corneal sensitivity and corneal subbasal nerve morphology in the cornea after deep anterior lamellar keratoplasty (DALK) compared with penetrating keratoplasty (PK). METHODS: This prospective study compared the changes in 16 eyes of 16 patients who underwent DALK (DALK group) with those in 28 eyes of 28 patients who underwent PK (PK group). Thirty healthy volunteers were also included as controls. Tear functions were evaluated using tear break-up time (TBUT), tear meniscus height (TMH) and corneal fluorescein staining. Corneal sensation was measured with a Cochet-Bonnet esthesiometer. Corneal subbasal nerve morphology was evaluated using in vivo confocal microscopy (IVCM). The patients were examined 1, 3, 6, 9 and 12 months after keratoplasty. RESULTS: Postoperatively, TMH recovered significantly faster in the DALK group than in the PK group (p < 0.05), and the postoperative TBUT was much higher in the DALK group compared with the PK group (p < 0.05). Central and peripheral corneal sensitivity remained lower in both the PK and DALK groups at 12 months after surgery compared with the control group (p < 0.05). The peripheral corneal sensitivity of the host cornea was significantly higher than the central corneal sensitivity (p < 0.05). No significant difference was found in corneal sensitivity between the PK and DALK groups. There was no significant correlation between corneal sensitivity and tear film function after PK or DALK. CONCLUSIONS: Tear film function was restored more rapidly after DALK compared with PK, but there was no significant difference in corneal sensitivity between PK and DALK.

The experimental treatment of corneal graft rejection with the interleukin-1 receptor antagonist (IL-1ra) gene.

PURPOSE: To investigate the protective effects of interleukin-1 receptor antagonist (IL-1ra) gene transfer in a rat model of corneal graft rejection. METHODS: We constructed a recombinant plasmid (pcDNA3.1-hIL-1ra) with high IL-1ra expression in eukaryotic cells. Using a Wistar-SD rat model of corneal graft rejection, we examined the effects of IL-1ra in vivo after cationic polymer jetPEI-mediated nonviral gene delivery. Four groups were included: negative controls (group I, n = 20), pcDNA3.1-hIL-1ra corneal stromal injection (group II, n = 34), pcDNA3.1-hIL-1ra anterior chamber injection (group III, n = 34), and 500 µg/ml IL-1ra protein subconjunctiva injection (group IV, n = 20). IL-1ra expression after transfection was evaluated by real-time polymerase chain reaction (RT-PCR) and western blotting. The rejection indices of corneal grafts were analysed in the different groups. The expression levels of transforming growth factor ß1 (TGF-ß1), inflammatory chemokines including RANTES, interleukin-1 (IL-1) and the numbers of CD4+ and CD8+ T cells in the grafts were determined by biochemical assays at different time points after corneal transplantation. RESULTS: Various degrees of inflammatory cell infiltration and graft neovascularisation were observed by histopathology. After injecting the pcDNA3.1-hIL-1ra plasmid into the cornea, IL-1ra mRNA and protein expression was detected in the corneal stroma and reached a peak on day 3. The graft survival curves indicated that the corneal transparency rates of grafts in the IL-1ra gene-treated group and the IL-1ra protein-treated group were higher compared with the untreated group (P<0.05). During the period of acute rejection, TGF-ß1, RANTES, IL-1α and IL-1ß levels in the grafts in the IL-1ra treatment groups were lower than the control group (P<0.05). CD4+ and CD8+ T cell counts were reduced significantly in the corneal grafts of groups II, III and IV compared with group I (P<0.05). CONCLUSION: Interleukin-1 receptor antagonist (IL-1ra) gene transfer treatment inhibits graft rejection after corneal transplantation through the downregulation of immune mediators.