Transplantation of tissue-engineered human corneal epithelium in limbal stem cell deficiency rabbit models

AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye in morphology and structure. In contrast, intense corneal edema, turbid, invaded blood vessels were found in dAM eyes, and no multilayer epithelium was found but only a few scattered conjunctiva-like cells appeared. CONCLUSION: The TE-HCEP, with similar morphology and structure to those of innate HCEP, could reconstruct a multilayer corneal epithelium with normal functions in restoring corneal transparency and thickness of LSCD rabbits after transplantation. It may be a promising HCEP equivalent for clinical therapy of corneal epithelial disorders.

In vitro reconstruction and characterization of tissue-engineered human corneal epithelium with seeder cells from an untransfected human corneal epithelial cell line

AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were reconstructed in vitro with seeder cells from an untransfected HCEP cell line, and scaffold carriers of denuded amniotic membrane (dAM) in air-liquid interface culture for 3, 5, 7 and 9 days, respectively. The specimens were examined with hematoxylin-eosin (HE) staining of paraffin-section, immunocytochemical staining, scanning and transmission electron microscopy. RESULTS: During in vitro reconstruction of TE-HCEP, HCEP cells formed a 3-4, 6-7 and 8-10 layers of an HCEP-like structure on dAMs in air-liquid interface culture for 3, 5 and 7 days, respectively. But the cells deceased to 5-6 layers and the structure of straified epithelium became loose at day 9. And the cells maintained positive expression of marker proteins (keratin 3 and keratin 12), cell-junction proteins (zonula occludens-1, E-cadherin, connexin 43 and integrin beta 1) and membrane transport protein of Na+-K+ ATPase. The HCEP cells in TE-HCEP were rich in microvilli on apical surface and established numerous cell-cell and cell-dAM junctions at day 5. CONCLUSION: The morphology and structure of the reconstructed TE-HCEP were similar to those of HCEP in vivo. The HCEP cells in the reconstructed TE-HCEP maintained the properties of HCEP cells, including abilities of forming intercellular and cell-extracellular matrix junctions and abilities of performing membrane transportation. The untransfected HCEP cells and dAMs could promisingly be used in reconstruction HCEP equivalent for clinical corneal epithelium transplantation.

Netrin-1 promotes epithelium repair in corneal injury

●AIM:To explore netrin-1 functions on corneal epithelium in vitro and in vivo.●METHODS:In vitro the human corneal epithelial(HCE)cells were treated with serum free DMEM-F12 basic media containing 0,50,100,200,300,500,800,and 1000 ng/mL of netrin-1,respectively.The cells viability was detected by cell counting kit-8(CCK-8).The wound-healing assay was applied to assess the migration proficiency of HCE cells.Flow cytometry was used to analyze the cell-cycle distribution and apoptosis.In vivo,normal c57(6 wk)mice were demarcated with a trephine in the middle of the cornea to produce a 3-mm circular wound.Mice corneas were inflicted no epithelium with a 3-mm wound displayed,but remained the limbal epithelium intact.A blunt scalpel blade was used to remove the corneal epithelian cells,followed by topical netrin-1 application(200 ng/mL),and the group treated by PBS as control.The treated group was injected netrin-1 into the normal c57 mice inferior subconjunctival 4 h before trauma.Mouse corneal inflammation and neovascularization were observed under slit lamp microscope.The apoptosis of corneal cells was determined by TUNEL staining.●RESLUTS:A concentration of 200 ng/mL netrin-1 enhanced 25%of the HCE viability.The relative migration rates were 76.3%and 100%in control and netrin-1 treated group after cultured 72 h.Treated with netrin-1(200 ng/mL)decreased the apoptosis of HCE cells,as well as decreased their percentage from 19.3%±0.57%to 12.7%±0.42%of the total.The remaining wound area was 1.22 mm2 in control group but 0.22 mm2 in the netrin-1 treated group.Exogenous Netrin-1 inhibits apoptosis of corneal epithelial cells of c57 mice.TUNEL-positive cells at the epithelial layer of the corneas of the control and netrin-1 treated c57 mice at 24 h after wounding were 43.3%and 16.7%respectively.●CONCLUSION:Netrin-1 can reduce HCE apoptosis as well as promote its proliferation and migration.Topical application of netrin-1 promotes the injuryed cornea epithelial wound repair and inhibits apoptosis of corneal epithelial cells.These findings may offer potential therapies to repair the defects of corneal epithelial based on netrin-1.

TREM-1 expression in rat corneal epithelium with Aspergillus fumigatus infection

AIM: To investigate the expression of triggering receptor expressed on myeloid cells-1(TREM-1) in the aberrant inflammation within the corneal epithelium at early period of fungal infection.METHODS: A total of 65 Wistar rats were randomly divided into control group, sham group and fungal keratitis(FK) group, in which the cornea was infected by Aspergillus fumigatus(A. fumigatus). After executed randomly at 8, 16, 24, 48 and 72 h after experimental model being established, the severity of keratomycosis in rats was scored visually with the aid of a dissecting microscope and slit lamp. Then corneas in three groups were collected to assess the expression of TREM-1through quantitative reverse transcription-polymerase chain reaction(RT-PCR), immunofluorescence technique and Western blot analysis. The correlation between FK inflammation and expression of TREM-1 was also analyzed.RESULTS: Corneal inflammation scores increased with time after fungal infection(F =49.74, P =0.000). The inflammation scores in FK group were obviously higher than those in sham group on the whole(F =137.78, P =0.000). Levels of TREM-1 in the infected rat corneal epithelium had elevated at 8h and peaked at 48h(P 【0.001,compared with control group). Western blot analysis also showed an obviously elevated TREM-1 level in rat corneal epithelium at 24 h and 48 h after fungal infection.Immunofluorescence technique showed that TREM-1mainly existed in corneal epithelium and infected corneal stoma of rat. TREM-1 protein expression was enhanced after fungal infection. Moreover, severity of FK inflammation was significantly related to TREM-1expression in FK(r =0.942, P =0.000).CONCLUSION: TREM-1 may contribute to amplify theinflammation in the cornea infected with A. fumigatus and play critical roles in the battle against A. fumigatus in the innate immune responses.

Anti-inflammatory and anti-apoptotic effects of N-acetylcysteine in diabetic rat corneal epithelium

AIM:To characterize the anti-inflammatory and antiapoptotic effects of N-acetylcysteine(NAC)in streptozotocin(STZ)-induced diabetic rat corneal epithelium and human corneal epithelial cells(HCECs)exposed to a high-glucose environment.METHODS:HCECs were incubated in 0,5,50 mmol/L glucose medium,or 50 mmol/L glucose medium with NAC for 24h.Diabetes was induced in rats by intraperitoneal injection of 65 mg/kg STZ and some of these rats were topically administered NAC to corneas with 3 mice per group.We characterized receptor for advanced glycation end-products(RAGE)expression using immunofluorescence,and interleukin(IL)-1βand cleaved caspase-3(CCAP-3)expression using immunohistochemistry.Circulating tumor necrosis factor(TNF)-αconcentration was measured by ELISA and cleaved poly-ADP ribose polymerase(PARP)concentration was quantified by Western blotting.Apoptotic cells were detected using TUNEL assay and annexin V and propidium iodide staining.RESULTS:Diabetic rats had higher expression of RAGE(2.46±0.13 fold),IL-1β,and CCAP-3 in apoptotic cells of their corneas than control rats.The expression of RAGE(1.83±0.11 fold),IL-1β,and CCAP-3,and the number of apoptotic cells,were reduced by topical NAC treatment.HCECs incubated in 50 mmol/L glucose medium showed high concentrations of TNF-α(310±2.00 pg/mL)and cleaved PARP(7.43±0.56 fold),and more extensive apoptosis than cells in 50 mmol/L glucose medium.However,the addition of NAC reduced the concentrations of TNF-α(153.67±2.31 pg/mL)and cleaved PARP(5.55±0.31 fold)and the number of apoptotic cells.CONCLUSION:NAC inhibits inflammation and apoptosis in the corneas of diabetic rats and HCECs maintained in a high-glucose environment.

Expression of vitamin D receptor and cathelicidin in human corneal epithelium cells during fusarium solani infection

AIMTo observe the expression of vitamin D receptor (VDR) in human specimen and immortalized human corneal epithelium cells (HCEC) when challenged with fusarium solani. Moreover, we decided to discover the pathway of VDR expression. Also, we would like to detect the expression of cathelicidin antimicrobial peptide (CAMP) in the downstream pathway of VDR.METHODSImmunohistochemistry was used to examine the VDR expression in HCEC from healthy and fungal keratitis patients. Real time quantitative polymerase chain reaction (qPCR) was performed to observe the messenger ribonucleic acid (mRNA) change of VDR when immortalized HCEC were challenged with fusarium solani for different hours. CAMP was detected at both mRNA and protein levels.RESULTSWe found out that the VDR expression in fusarium solani keratitis patients' specimen was much more than that in healthy people. The mRNA and protein expression of VDR increased when we stimulated HCEC with fusarium solani antigen (P<0.01) and it could be inhibited by toll like receptor 2 (TLR2) monoclonal antibody. The CAMP expression was decreased because of fusarium solani antigen stimulation (P<0.01).CONCLUSIONThe VDR expression can be increased via TLR2/1-VDR pathway while the CAMP expression is decreased by the stimulation of fusarium solani antigen.

Central corneal epithelium self-healing after ring-shaped glycerin-cryopreserved lamellar keratoplasty in Terrien marginal degeneration

Dear Sir, I am Dr Yan-Long Bi, from the Department of Ophthalmology, Tongji University Affiliated to Tongji University School of Medicine, Shanghai, China. I write to present a case report of total limbal stem cells deficiency after treatment with ring-shaped lamellar keratoplasty secondary to Terrien marginal degeneration. During 3 years

STUDY IN CYTOTOXICITY OF GENTAMYCIN TO CORNEAL EPITHELIUM AND ENDOTHELIUM IN TISSUE CULTURE

A study in cytotoxicity of gentamyein to tissue-cultured bovine corneal endothelial cells and rabbit corneal epithelial cells is reported. When the cultured cells reached confluence, they were exposed to tissue culture media containing gentamycin for 6 hours. We founl that 0.5% gentamycin caused significant damage to corneal epithelial cells---diffuse plasmolysis, with scattered cell necrosis and 5% loss.While corneal endothelial cells were exposed to 1.6 mg/ml gentamycin, extensive cell loss (approximate- ly 15%) was observed. The damaged cells recovered their normal morphology after 24 hours. When the concentration of gentamycin increased twice, serious damage to cells occured. The area of cell loss reached 40%, and the recovery of cellular morphology Was much slower. This study demonstrates that gentamycin potential cytotoxicity to corneal epithelium and endothelium, suggesting that gentamycin should be rationally used in the treatment of ocular diseases.

Reconstruction of Rabbit Corneal Layer Composed of Corneal Fibroblasts and Corneal Epithelium on the Lyophilized Amniotic Membrane

Many researchers have employed the cryopreserved amniotic membrane（CAM） and corneal epithelial cells in the treatment of a severely damaged burned cornea, with corneal epithelial cells cultured on an amniotic membrane （AM）. The lyophilized amniotic membrane（LAM） has a higher graft take and a longer shelf life; it is easier to store and safer because of gamma irradiation. Two Teflon rings（ Ahn＇s supporter） were made for culturing the cells on the LAM, and were then used to support the LAM. To reconstruct a corneal layer composed of corneal fibroblasts and epithelium, the corneal fibroblasts were first cultivated on the stromal side of LAM for five days, foUowed by epithelial cells culture on the epithelial side, by using the air-liquid interface culture. The reconstructed corneal layer composed of corneal fibroblasts and corneal epithelial cells has a much healthier basal layer of corneal epithelium than the reconstructed corneal epithelium, which was got by using only corneal epithelial cells, and resembles the epithelium of normal corneas, without the horny layer. Thus, the reconstruction of the corneal layer by using a LAM is considered to be a good in vitro model, not only for its application in toxicological test kits, but also for transplantation in patients with a severely damaged cornea.

EFFECT OF HUMAN AMNIOTIC MEMBRANE ON CORNEAL EPITHELIUM AND YAC-1 CELL

Objective To study the effect of the amniotic membrane on enhancing the proliferation ofcorneal epithelia and YAC-1 cell. Methods After the primary culture of the rabbit's corneal epithelia and YAC-1 cells, they were seeded on the upper surface or stromal matrix side of amniotic membrane respectively. The proliferation results were observed by MTT test. Results The amniotic membrane was found significantly enhancing the proliferation of corneal epithelia on the d1 ,d3 , and d5 after culture. The proliferation rate was 28.93% ,23.32% ,23.41 % (P<0 .05) respectively, but the d7 proliferation rate was 20.72% (P> 0.05). On the dl , d3 , d7 after culture , the YAC-1 cells proliferation rate was 34 .87% ,36 .28% ,33 .86% (P< 0.01) respectively. Conclusion Our results demonstrated that the amniotic membrane could enhance the proliferation of both corneal epithelia and YAC-1 cells significantly. Although amniotic membrane has been suggested as an ideal material for reconstruction of ocular surface, special attention should be paid during amniotic membrane transplantation for treating ocular surface lesion resulted from epibulbar tumors.

Transplantation of human limbal cells cultivated on amniotic membrane for reconstruction of rat corneal epithelium after alkaline burn

BACKGROUND: The transplantation of limbal epithelial cells cultivated on amniotic membrane is a newly developed treatment for limbal stem cell deficiency. The purpose of our study was to investigate the biological characteristics of limbal epithelial cells and evaluate the effect of transplantation of cultivated human limbal epithelial cells on ocular surface reconstruction in limbal stem cell deficiency rat model. METHODS: Human limbal cells were isolated and cultivated in vitro. Cytokeratins 3, 12, and 19 (K3, K12 and K19) and p63 were detected by immunofluorescent staining or RT-PCR. BrdU labelling test was used to identify the slow cycling cells in the cultures. Limbal stem cell deficiency was established in rat cornea by alkali burn. Two weeks after injury, the rats received transplants of human limbal stem cells cultivated on amniotic membrane carrier. The therapeutic effect was evaluated by slit lamp observation, Hemotoxin and Eosin (HE) staining and immunofluorescent staining. RESULTS: On day 7 in primary culture, p63 and K19 were strongly expressed by most cells but only a few cells expressed K3. On days 14 and 21, p63 and K19 were still expressed by a majority of cells, but the expressive intensity of p63 decreased in a number of cells, while the proportion of K3 positive cells increased slightly and some cells coexpressed p63 and K3. RT-PCR showed that gene expression of both p63 and K12 were positive in cultivated limbal cells, but in mature superficial epithelial cells, only K12 was detected. BrdU labelling test showed that most cells were labelled with BrdU after 7 days' labelling and BrdU label retaining cells were observed after chasing for 21 days with BrdU free medium. For in vivo test, slit lamp observation, HE staining and immunofluorescent staining showed that the rats receiving transplant of human limbal stem cells cultivated on amniotic membrane grew reconstructed corneas with intact epithelium, improved transparency and slight or no neovascularization. A majority of epithelial cells of the reconstructed cornea were positive to antihuman nuclear antibody and cells expressing K3 were found mainly in superfacial epithelium. CONCLUSIONS: Limbal stem cells can be cultivated in vitro: the cells are characterized by high proliferation and slow cycling and identified as p63/K19 positive and K3/K12 negative. During culture, some stem cells can proliferate and differentiate into mature cornea epithelial cells. Amniotic membrane is a suitable carrier for limbal stem cells. Transplantation of human limbal stem cells cultivated on amniotic membrane can functionally reconstruct rat cornea with limbal stem cell deficiency.

Application of stem cell-derived retinal pigmented epithelium in retinal degenerative diseases： present and future

As a constituent of blood-retinal barrier and retinal outer segment（ROS） scavenger, retinal pigmented epithelium（RPE） is fundamental to normal function of retina. Malfunctioning of RPE contributes to the onset and advance of retinal degenerative diseases. Up to date, RPE replacement therapy is the only possible method to completely reverse retinal degeneration. Transplantation of human RPE stem cell-derived RPE（h RPESC-RPE） has shown some good results in animal models. With promising results in terms of safety and visual improvement, human embryonic stem cell-derived RPE（h ESC-RPE） can be expected in clinical settings in the near future. Despite twists and turns, induced pluripotent stem cell-derived RPE（i PSC-RPE） is now being intensely investigated to overcome genetic and epigenetic instability. By far, only one patient has received i PSCRPE transplant, which is a hallmark of i PSC technology development. During follow-up, no major complications such as immunogenicity or tumorigenesis have been observed. Future trials should keep focusing on the safety of stem cell-derived RPE（SC-RPE） especially in long period, and better understanding of the nature of stem cell and the molecular events in the process to generate SC-RPE is necessary to the prosperity of SC-RPE clinical application.

Influence of Preservation Solutions and Bile on a Human Bile Duct Epithelium Cell Line: An <i>In-Vitro</i>Study

Introduction: Bile duct complications are common after liver transplantation. The impact of preservation solution is unclear. Aim: We investigated the impact of different preservation solutions with and without diluted bile on a human biliary tract carcinoma cell line. Methods: The human biliary tree carcinoma cell line SK-ChA-1 was cultured with either medium or University of Wisconsin solution (UW), histidine-tryptophane-ketoglutarate (HTK) solution, Celsior or physiological saline for 6h, 10h or 12h at 6℃- 8℃ and metabolic activity was measured by a MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)-test immediately, after 12h or 24h. Cells were also incubated in combination with diluted porcine bile. Results: Immediately after cold storage of 6h HTK and UW decreased metabolic activity whereas Celsior increased metabolic activity after 10h or 12h of cold ischemia. After 12h or 24h no major differences were found any more. Incubation with bile in combination with HTK, Celsior or NaCl decreased metabolic activity, whereas UW abolished this effect. Conclusion: On a cellular level differences between preservation solutions were found, especially in combination with bile. Further studies are warranted to determine whether this results in clinically significant differences in biliary complications.

Efficacy of rhNGF-loaded amniotic membrane transplantation for rabbit corneal epithelial and nerve regeneration

AIM:To evaluate the efficacy of recombinant human nerve growth factor-loaded amniotic membrane(rh NGF-AM)on corneal epithelial and nerve regeneration in rabbit model.METHODS:Freshly prepared human amniotic membrane(AM)were immersed into PBS buffer containing 100 or 500μg/mL rh NGF for 15,30,and 60 min at 4℃.The in vitro release kinetics of rh NGF was measured with ELISA.For in vivo evaluation,the AM were immersed with 500μg/mL rh NGF for 30 min.Fifty-seven rabbits were selected to establish corneal epithelial defect model.In addition to the 19 rabbits in control group,38 rabbits received AM transplantation with or without rh NGF after the removal of central epithelium.Corneal epithelial defect area,sub-epithelial nerve fiber density,corneal sensitivity,rh NGF contents in resident AM and corneas were measured after the surgery.RESULTS:rh NGF was sustained release from the AM within 14 d in vitro,with the positive correlation with initial immersion concentration.The immersion of AM in 500μg/mL rh NGF for 30 min achieved the most stable release within 14 d.After transplantation in rabbit cornea,a high concentration of rh NGF in resident rh NGF-AM and cornea was maintained within 8 d.Corneal epithelial healing,nerve fiber regeneration and the recovery of corneal sensitivity were significantly accelerated after the rh NGF-AM transplantation when compared to simple AM transplantation(all P<0.05).CONCLUSION:Simple immersion of AM achieves the sustained release of rh NGF,and promotes corneal epithelial wound healing and nerve regeneration,as well as the recovery of corneal sensitivity in rabbit.

Mesenchymal stem cells: Potential role in corneal wound repair and transplantation

Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy after corneal transplantation remain prob-lematic. Mesenchymal stem cells(MSCs) derived from bone marrow or other adult tissues can differentiate into various types of mesenchymal lineages, such as osteocytes, adipocytes, and chondrocytes, both in vivo and in vitro. These cells can further differentiate into specific cell types under specific conditions. MSCs migrate to injury sites and promote wound healing by secreting anti-inflammatory and growth factors. In ad-dition, MSCs interact with innate and acquired immune cells and modulate the immune response through their powerful paracrine function. Over the last decade, MSCs have drawn considerable attention because of their beneficial properties and promising therapeutic prospective. Furthermore, MSCs have been applied to various studies related to wound healing, autoim-mune diseases, and organ transplantation. This review discusses the potential functions of MSCs in protecting corneal tissue and their possible mechanisms in corneal wound healing and corneal transplantation.

Effect of amnion membrane transplantation on corneal neovascularization in 10 patients with alkali burn

By observing clinical cases, we studied the curative effect of amnion membrane transplantation on decreasing corneal neovascularization (CNV). It was a non-randomized retrospective case-control study. Among 17 cases (21 eyes) of third-degree alkali burns from 2007 to 2010, 10 cases (12 eyes) were performed with amnion membrane transplantation operation, and others were not. Amnion membrane transplantation was performed at the 3rd day after burn in the treatment group. Areas of CNV in double groups were measured at the 14th day and 60th day after burn. Area of CNV in the treatment group was (66.207±7.251)mm2 at the 14th day after burn, and was 18.27% lower than that in the control group. Area of CNV in the treatment group was (120.046±13.812)mm2 at the 60th day after burn, and was 11.35% lower than that in the control group. There was both statistical significance (P<0.05). Amnion membrane transplantation operation can inhibit the growth of corneal neovascularization induced by alkali burn.

Preoperative evaluation and outcome of corneal transplantation for limbal dermoids：aten-yearfollow-up study

AIM： To summarize preoperative evaluation and outcome of corneal transplantation for limbal dermoids for ten years.METHODS： Eighty-five patients diagnosed with limbal dermoids and treated with corneal transplantation were analyzed retrospectively. All patients were further divided into two groups according to absence or presence of neovascularization surrounding the dermoids in the corneal stroma. Eighty-two eyes were treated with tumor excision combined with partial lamellar sclerokeratoplasty, and the other three eyes were performed by penetrating keratoplasty. The size and location of the tumor, the associated ocular and systemic anomalies, the depth of the corneal penetration of tumor tissues, the preoperative and postoperative best-corrected visual acuity （BCVA）, graft survival and cosmetic outcome, and surgical complications were recorded respectively.RESULTS： The average age at surgery was 5.3y （range, 3mo-36y）. The mean size of dermoids was 6.1±1.6 mm. The 43.5% of eyes （37/85） were present with hair at the surface of the dermoid and 72.9% of dermoids were located inferotemporal of the eye. Amplyopia was present in 34.1% of patients （29/85） and 9.4% of patients （8/85） had lipodermoids. Eighteen patients suffered from Goldenhar’s syndrome with an accessory ear. The 75% of patients in group 1 had involvement of the corneal deep stroma down to Descemet’s membrane without involving it, but 71.4% of patients had Descemet’s membrane involvement in group 2. Preoperative BCVA ranged from counting fingers to 20/20. Postoperatively 81.1% had a BCVA of 20/800 or better. There was no significant difference between the post-surgical BCVA of the two groups （t=1.584, P〉0.05）. The grafts of 70.5% patients were present as 1＋ opacity, 21.1% as 2＋ opacity, 8.2% as 3＋ opacity and none as 4＋ opacity. Surgical complications included graft rejection, microperforation, prolonged reepithelialization, steroid glaucoma, interface neovascularization, and interface hemorrhage.CONCLUSION： The dermoids with neovascularization surrounding them in the corneal stroma invaded deeper tissues in the cornea than those with no neovascularization surrounding them in the corneal stroma. Therefore, surgeons should take care to avoid corneal perforation during the corneal transplantation operation. The majority of patients markedly improved their cosmetic appearance after surgery.

The lived experiences of patients undergoing acellular porcine corneal stroma transplantation

To explore the lived experiences of patients undergoing acellular porcine corneal stroma（APCS）transplantation,a descriptive,qualitative design was performed.A purposive sample of 13 patients who underwent APCS transplantation to treat progressive infectious keratitis were enrolled in the semi-structured,open-ended interviews.The taped and transcribed interviews were analyzed using a thematic analysis approach.Alterations in the transparency of APCS grafts were accompanied by a gradual improved visual acuity（before surgery：1.38±0.91 logMAR;3mo postoperatively ：0.40±0.24 logMAR, respectively）.Accordingly,in terms of lived experiences,the patients generally reported＂negative＂experiences before the operation and during the early postoperative period,but this was greatly improved 3mo after surgery.Four main themes were derived：anxiety and fear,stigma,lifestyle change,and gratitude and insights. Conclusively,health care professionals should provide holistic care for patients,proactively promoting patients’physical and mental health.

Therapeutic effect of microencapsulated porcine retinal pigmented epithelial cells transplantation on rat model of Parkinson's disease

Object To investigate the therapeutic effect of microencapsulated porcine retinal pigmented epithelial cells （RPE-M） transplantation on rat model of Parkinson＇s disease （PD）. Methods Primary porcine RPE cells were harvested by enzyme digestion and expanded in culture medium. Determine the levels ofdopamine （DA） and homovanillic acid （HVA） by high performance liquid chromatography electrochemical （HPLC） assay, and the levels of brain-derived neurotrophic factor （BDNF） and glial-derived neurotrophic factor （GDNF） were detected by ELISA. Alginate-polylysine-alginate （APA） microencapsulated cells were produced by using a high voltage electrostatic system. PD rat model was established by unilateral injection of 6-hydroxydopamine （6-OHDA） into the medial forebrain bundle （MFB）. After that, the RPE-M was transplanted into the corpus striatum of PD rat, and then the rotation test scores were recorded and biochemical changes of the corpus striatum were tested. Results The levels of DA, HVA, BDNF and GDNF secreted by RPE were stable in the RPE culture supernatant and were not changed by the microencapsulation. Eighty-three percent rats developed PD by unilateral lesion of 6-OHDA in the MFB. The RPE-M transplantation had therapeutic effect on 33% PD rats. Conclusion Porcine RPE cells grow actively in vitro and could secrete DA, HVA, BDNF, and GDNF constantly, which does not be affected by the passage culture and the APA miroencapsulation. RPE-M transplantation of may be a curative therapy for PD.

Organ transplantation scandal influencing corneal donation rate

~ In the majority of countries, there is a shortage of donor corneas for corneal transplantations. This study investigated the impact of organ transplantation scandals on corneal donation rate at the University Hospital T/ibingen. Each deceased patient was considered as a potential corneal donor. An ophthalmic resident handled with stable methods of procedures the corneal donor procurement from 2009 to 2015. The rates of corneal donation were examined and analyzed. Among the 5712 hospital deaths, consent for corneal donation was obtained in 711 cases. The mean annual corneal donation rate was 12.4%. Since 2009, the donation rate per year could be increased with exception of 2013 and 2015. In the end of 2012 and 2014 two huge organ donation scandals were known in Germany. In the following years 2013 and 2015 corneal donation rate decreased significantly （P=0.0181 and P=0.0006）. We concluded that transplantation scandals have a significant impact on corneal donation rate. Improving professional＇s performance through full transparency and honesty is very important to earn trust of potential donors and their families.