Amniotic membrane mesenchymal stromal cell-derived secretome in the treatment of acute ischemic stroke:A case report

BACKGROUND Stroke is the second and third leading cause of death and disability,respectively.To date,no definitive treatment can repair lost brain function.Recently,various preclinical studies have been reported on mesenchymal stromal cells(MSCs)and their derivatives and their potential as alternative therapies for stroke.CASE SUMMARY A 45-year-old female suffered an acute stroke,which led to paralysis in the left upper and lower limbs.The amniotic membrane MSC-derived secretome(MSCsecretome)was intravenously transplanted once a week for 4 wk.MSC-secretomeregulated regulatory T cells were investigated for the beneficial effects.The clinical improvement of this patient was accompanied by an increased frequency of regulatory T cells after transplantation.CONCLUSION Intravenous administration of MSC-secretome can potentially treat patients who suffer from acute ischemic stroke.

Amniotic membrane transplantation: an updated clinical review for the ophthalmologist

Although amniotic membrane transplantation(AMT)has long been used as an essential surgical technique for ocular surface reconstruction,its role continues to evolve and expand.In the management of numerous ocular surface disorders,ranging from inflammatory to infectious,traumatic to neoplastic,the ability to perform AMT is a valuable addition to the skillset of any ophthalmologist.The purpose of this paper is to provide ophthalmologists with an updated,evidence-based review of the clinical indications for AMT in corneal and conjunctival reconstruction,reviewing its common and even experimental applications known to date.The methods of amniotic membrane preservation,the available commercial amniotic membrane products to date,and future directions for amniotic membrane use,including amniotic membrane extract eye drops(AMEED),are also discussed.It is paramount for ophthalmologists to stay up-to-date on the applications of AMT so as to effectively incorporate this versatile treatment modality into their practice,both in the operating room and in the clinic.By familiarizing the general ophthalmologist with its diverse applications,we hope to motivate general ophthalmologists to incorporate the use of AMT into their clinical practice,or provide guidance on how to recognize when referral to a corneal specialist for amniotic membrane application is prudent.

Establishment of an untransfected human corneal epithelial cell line and its biocompatibility with denuded amniotic membrane

AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors, yielding an HCEP cell line which was its growth performance, chromosome morphology, tumorigenicity and expression of marker proteins analyzed. In addition, the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light, electron and slit-lamp microscopies. RESULTS: HCEP cells proliferated to confluence in 3 weeks, which have been subcultured to passage 160. A continuous untransfected HCEP cell line, designated as utHCEPC01, was established with a population doubling time of 45.42 hours as was determined at passage 100. The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3. They, with no tumorigenicity, formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture, maintained expression of marker proteins including keratin 3 and integrin p 1 and attached tightly to dAMs. The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original. CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study. The cells maintained expression of marker proteins. The cell line was biocompatible with dAM. It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP, promising for the treatment of diseases caused by corneal epithelial disorders.

Clinical outcome of combined conjunctival autograft transplantation and amniotic membrane transplantation in pterygium surgery

AIM： To compare long-term outcome of primary and recurrent pterygium surgery with three different techniques： combined conjunctival autograft and overlay amniotic membrane transplantation （CAT with AMT）, conjunctival autograft transplantation （CAT） alone and amniotic membrane transplantation （AMT） alone. METHODS： In this retrospective study, 142 eyes of 142 pterygium patients （104 primary, 38 recurrent）who underwent CAT （group A）, AMT （group B） or CAT with AMT （group C） respectively following surgical excision were reviewed and compared based on the recurrences and post-operative complications. RESULTS： The number of recurrence post-surgery were 17 （9 from primary, 8 from recurrent; the same description below）, 18 （10, 8） and 2 （1, 1） in groups A, B, and C respectively; dry eyes were 22 （16, 6）, 27 （18, 9） and 7 （3, 4）; conjunctival inflammations were 30 （17, 13）, 27 （16, 11） and 11 （6, 5）. Patients in group C （either pdmary or recurrent or both） mainly showed significantly better results than those in group A or B （P〈0.05） regarding above-mentioned clinical effects. CONCLUSION： Combined CAT and overly AMT have significantly lower rates of recurrence and postoperative complications for primary and recurrent pterygium surgery than CAT or AMT alone.

Strain and stress variations in the human amniotic membrane and fresh corpse autologous sciatic nerve anastomosis in a model of sciatic nerve injury

A 10-mm long sciatic nerve injury model was established in fresh normal Chinese patient cadavers. Amniotic membrane was harvested from healthy maternal placentas and was prepared into multilayered,coiled,tubular specimens.Sciatic nerve injury models were respectively anastomosed using the autologous cadaveric sciatic nerve and human amniotic membrane.Tensile test results showed that maximal loading,maximal displacement,maximal stress,and maximal strain of sciatic nerve injury models anastomosed with human amniotic membrane were greater than those in the autologous nerve anastomosis group.The strain-stress curves of the human amniotic membrane and sciatic nerves indicated exponential change at the first phase,which became elastic deformation curves at the second and third phases,and displayed plastic deformation curves at the fourth phase,at which point the specimens lost their bearing capacity.Experimental findings suggested that human amniotic membranes and autologous sciatic nerves exhibit similar stress-strain curves, good elastic properties,and certain strain and stress capabilities in anastomosis of the injured sciatic nerve.

Human umbilical cord mesenchymal stem cell-loaded amniotic membrane for the repair of radial nerve injury

In this study, we loaded human umbilical cord mesenchymal stem cells onto human amniotic membrane with epithelial cells to prepare nerve conduits, i.e., a relatively closed nerve regeneration chamber. After neurolysis, the injured radial nerve was enwrapped with the prepared nerve conduit, which was fixed to the epineurium by sutures, with the cell on the inner surface of the conduit. Simultaneously, a 1.0 mL aliquot of human umbilical cord mesenchymal stem cell suspension was injected into the distal and proximal ends of the injured radial nerve with 1.0 cm intervals. A total of 1.75 x 107 cells were seeded on the amniotic membrane. In the control group, patients received only neurolysis. At 12 weeks after cell transplantation, more than 80% of patients exhibited obvious improvements in muscular strength, and touch and pain sensations. In contrast, these improvements were observed only in 55-65% of control patients. At 8 and 12 weeks, muscular electrophysiological function in the region dominated by the injured radial nerve was significantly better in the transplantation group than the control group. After cell transplantation, no immunological rejections were observed. These findings suggest that human umbilical cord mesenchymal stem cell-loaded amniotic membrane can be used for the repair of radial nerve injury.

Human amniotic membrane transplantation: Different modalities of its use in ophthalmology

The amniotic membrane(AM) is the inner layer of the fetal membranes and consist of 3 different layers: the epithelium, basement membrane and stroma which further consists of three contiguous but distinct layers: the inner compact layer, middle fibroblast layer and the outermost spongy layer. The AM has been shown to have anti-inflammatory, anti-fibrotic, anti-angiogenic as well as anti-microbial properties. Also because of its transparent structure, lack of immunogenicity and the ability to provide an excellent substrate for growth, migration and adhesion of epithelial corneal and conjunctival cells, it is being used increasingly for ocular surface reconstruction in a variety of ocular pathologies including corneal disorders associated with limbal stem cell deficiency, surgeries for conjunctival reconstruction, as a carrier for ex vivo expansion of limbal epithelial cells, glaucoma surgeries and sceral melts and perforations. However indiscriminate use of human AM needs to be discouraged as complications though infrequent can occur. These include risk of transmission of bacterial, viral or fungal infections to the recipient if the donors are not adequately screened for communicable diseases, if the membrane is not processed under sterile condi-tions or if storage is improper. Optimal outcomes can be achieved only with meticulous case selection. This review explores the ever expanding ophthalmological indications for the use of human AM.

Amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis

AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into two groups randomly, the AMC group and the control group, ten patients each group. Both debridement of the infected cornea tissue and standard anti-fungus drugs treatments were given to every patients, monolayer amniotic membrane were sutured to the surface of the entire cornea and bulbar conjunctiva with 10-0 nylon suture for patients in the AMC group.The diameter of the ulcer was determined with slit lamp microscope and the depth of the infiltration was determined with anterior segment optical coherence tomography. Uncorrected visual acuity(UCVA) was tested before surgery and three month after healing of the epithelial layer. The healing time of the cornea epithelium, visual acuity(VA) was compared between the two groups using t- test.RESULTS:There was no statistical difference of the diameter of the ulcer, depth of the infiltration, height of the hypopyon and VA between the two groups beforesurgery(P 】0.05). The average healing time of the AMC group was 6.89 ±2.98 d, which was statistically shorter than that of the control group(10.23±2.78d)(P 【0.05).The average UCVA of the AMC group was 0.138 ±0.083,which was statistically better than that of the control group(0.053±0.068)(P 【0.05).CONCLUSION:AMC surgery could promote healing of cornea epithelium after debridement for fungal keratitis and lead to better VA outcome.

Autologous nerve anastomosis versus human amniotic membrane anastomosisA rheological comparison following simulated sciatic nerve injury

The sciatic nerve is biological viscoelastic solid,with stress relaxation and creep characteristics.In this study,a comparative analysis of the stress relaxation and creep characteristics of the sciatic nerve was conducted after simulating sciatic nerve injury and anastomosing with autologous nerve or human amniotic membrane.The results demonstrate that,at the 7 200-second time point,both stress reduction and strain increase in the human amniotic membrane anastomosis group were significantly greater than in the autologous nerve anastomosis group.Our findings indicate that human amniotic membrane anastomosis for sciatic nerve injury has excellent rheological characteristics and is conducive to regeneration of the injured nerve.

Effects of Honghua preserved amniotic membrane on scar healing in experimental glaucoma surgery

AIM:To investigate the efficacy and safety of Honghua preserved amniotic membrane(AM)for preventing scar formation of the filtering bleb in a rabbit model of glaucoma trabeculectomy surgery.METHODS:Totally 36 rabbits(36 eyes)were randomly divided into 3 groups:the experimental group(ocular trabeculectomy in combination with Honghua preserved AM transplantation),the control group(ocular trabeculectomy surgery in combination with AM implantation),and the blank group(single trabeculectomy).Clinical observations[including intraocular pressure(IOP),filtering blebs and complications],MassonTrichrome staining,real-time quantitative reverse transcription-polymerase chain reaction(real-time PCR),Western blot were performed on different time points(D1,D7,D14,D21 and D56)after the surgery.RESULTS:After operated for 14d,there were statistically significant differences in the filtering blebs compared to the situation before operation(P【0.05),whereas no statistically difference on that among three groups(P】0.05).After 21d,the IOP of experimental group was lowest(P【0.05).There was significant difference between control group and blank group(P【0.05).On postoperative D14,the mean number of fibroblasts in the experimental group was significantlylower(40.6±10.2)compared to those in the control group(54.4±10.8)and blank group(68.2±11.6)(P【0.05,respectively).The mean numbers of the macrophage in the experimental and control groups were respcitively significantly lower versus the blank group(P【0.05,P【0.05,respectively).Compared to that in blank group,the level of transforming growth factor-β(TGF-β1)expression in sclera and conjunctival areas was reduced in the experimental and control groups on protein and mRNA level(P【0.05),but not significant difference between these two groups(P】0.05).CONCLUSION:The trabeculectory surgery with Honghua preserved AM can control IOP,sustain the functional filtration bleb,inhibit the proliferation of fibroblasts and open the filtrating pathway on the rabbit glaucoma models.

Comparison of trabeculectomy and trabeculectomy with amniotic membrane transplantation in the same patient with bilateral glaucoma

AIM:To observe effects of trabeculectomy with amniotic membrane transplantation(AMT) in controlling postoperative intraocular pressure(IOP) in patients with medically uncontrolled glaucoma.·METHODS:This study included adult patients with requiring bilateral glaucoma surgery.Each patient underwent trabeculectomy(Non-AMT group) in one eye and with AMT(AMT group) in the other eye according to randomized principle.Success was defined as intraocular pressure(IOP) 【21mmHg without any anti-glaucoma medications at 24 months follow-up.The two groups were compared in terms of IOP,complications and success rate.·RESULTS:Thirty-four eyes of 17 patients were investigated in this study.There was no statistically signifcant difference in pre-operative IOP between the two groups.The mean IOP was lower in AMT group compared with Non-AMT group on follow up months 12,18,and 24.Postoperative complications were more frequent in Non-AMT group(35.3%,6/17) compared with AMT group(5.9%,1/17).The success rate of surgery was88.2%(15/17) in Non-AMT group and 100%(17/17) in AMT group.·CONCLUSION:Trabeculectomy with AMT is an effective procedure to reduce IOP and complications,thereby improving surgical success rates.

Study of self-made freeze-dried bilayered fibrin-binding amniotic membrane in ocular trabeculectomy in rabbits

AIM: To investigate the antifibrotic effect of freeze-dried bilayered fibrin-binding amniotic membrane on trabeculectomy in a rabbit model. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with natural bilayered fibrin-binding amniotic membrane) and the blank group (single trabeculectomy). Clinical observation, hematoxylin-eosin staining, Massion staining, real-time PCR and immunohistochemistry for alpha -SMA were performed on days 7, 14, 21 and 30 following surgery. RESULTS: Statistical differences were noted in survival. analysis and intraocular pressure(IOP) among groups on days 7, 14, 21 and 30 following surgery. Histology, immunohistochemistry and real-time PCR further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane resulted in good wound healing and no scar formation. CONCLUSION: Self-made freeze-dried bilayered fibrin-binding amniotic membrane may inhibit the formation of scarring in glaucoma after trabeculectomy.

Fresh human amniotic membrane effectively promotes the repair of injured common peroneal nerve

Suture and autologous nerve transplantation are the primary therapeutic measures for completely severed nerves. However, imbalances in the microenvironment and adhesion of surrounding tissues can affect the quality of nerve regeneration and repair. Previous studies have shown that human amniotic membrane can promote the healing of a variety of tissues. In this study, the right common peroneal nerve underwent a 5-mm transection in rats. Epineural nerve repair was performed using 10/0 non-absorbable surgical suture. The repair site was wrapped with a two-layer amniotic membrane with α-cyanoacrylate rapid medical adhesive after suture. Hindlimb motor function was assessed using footprint analysis. Conduction velocity of the common peroneal nerve was calculated by neural electrical stimulation. The retrograde axoplasmic transport of the common peroneal nerve was observed using fast blue BB salt retrograde fluorescent staining. Hematoxylin- eosin staining was used to detect the pathological changes of the common peroneal nerve sputum. The mRNA expression of axon regeneration-related neurotrophic factors and inhibitors was measured using real-time polymerase chain reaction. The results showed that the amniotic membrane significantly improved the function of the injured nerve;the toe spread function rapidly recovered, the nerve conduction velocity was restored, and the number of fast blue BB salt particles were increased in the spinal cord. The amniotic membrane also increased the recovery rate of the tibialis anterior muscle and improved the tissue structure of the muscle. Meanwhile, mRNA expression of nerve growth factor, growth associated protein-43, collapsin response mediator protein-2, and brain-derived neurotrophic factor recovered to near-normal levels, while Lingo-1 mRNA expression decreased significantly in spinal cord tissues. mRNA expression of glial-derived neurotrophic factor did not change significantly. Changes in mRNA levels were more significant in amniotic-membrane-wrapping-treated rats compared with model and nerve sutured rats. These results demonstrate that fresh amniotic membrane wrapping can promote the functional recovery of sutured common peroneal nerve via regulation of expression levels of neurotrophic factors and inhibitors associated with axonal regeneration. The study was approved by the Committee on Animal Research and Ethics at the Affiliate Hospital of Zunyi Medical University, China (approval No. 112) on December 1, 2017.

Clinical and impression cytology findings of amniotic membrane and oral mucosal membrane transplantation for the management of socket contracture

AIM:To investigate and compare the cytopathological and clinical effects of amniotic membrane transplantation(AMT)and oral mucosal membrane transplantation(OMMT)in socket contraction.METHODS:Twelve patients who could not be fitted with ocular prosthesis due to socket contracture were included in this study.Seven patients underwent AMT and 5 patients underwent OMMT.Thirteen patients who had healthy sockets were included as control group.Depth of inferior fornix,degree of inflammation,extent of the socket contracture and socket volume were measured in the preoperative period and at sixth and twelfth weeks postoperatively.Impression cytology of conjunctival fornices and tear transforming growth factor beta-1(TGFβ1)levels were determined.RESULTS:In the AMT group,socket volume and lower fornix depth values were significantly higher(P=0.030and P=0.004 respectively)and inflammation levels and impression cytology stages(P=0.037 and P=0.022respectively)were significantly lower in postoperative period compared to preoperative period.In the OMMT group,no statistical differences were found in terms of clinical parameters,inflammation levels and impression cytology stages of preoperative versus postoperative values.Preoperative tear TGFβ1 levels were higher in AMT and OMMT groups compared to the control group(25.5 ng/mL,26.3 ng/mL and 21.7 ng/mL respectively).Decreased tear TGFβ1 levels were observed in both the AMT and OMMT groups postoperatively(median decrease value=2.1 ng/mL and 2.7 ng/mL respectively).CONCLUSION:AMT is associated with postoperative improvement in inferior fornix depth,socket volume,inflammation and impression cytology levels and may bea more proper alternative method than OMMT in the management of socket contracture.

Clinical outcomes of amniotic membrane loaded with5-FU PLGA nanoparticles in experimental trabeculectomy

AIM: To evaluate the effect of amniotic membrane loaded with 5-fluorouracil poly(lactic-co-glycolic acid)(PLGA) nanoparticles(5-FU-NPs) in the surgical outcomes of experimental trabeculectomy in rabbits.METHODS: Thirty-two New Zealand white rabbits were randomly categorized into four groups with 8 rabbits in each group. Group 1, the control group, performed traditional trabeculectomy without adjuvant treatment.While the experimental groups performed compound trabeculectomy with different implantations including amniotic membrane(group 2), 5-FU-NPs(group 3) and amniotic membrane loaded with 5-FU-NPs(group 4).Clinical evaluations including IOP measurement and filtration bleb analysis were performed in all groups postoperatively.RESULTS: There is no significant difference of mean IOP in all groups at first 7d after surgery. While at P14,mean IOPs of experimental group 2(9.8 ±2.1 mm Hg),groups 3(8.9 ±2.8 mm Hg) and group 4(7.6 ±2.3 mm Hg)were significantly reduced compared to control group(12.4 ±2.6 mm Hg; n =8, P 【0.05). At P21, mean IOPs of groups 3(11.7±3.2 mm Hg) and group 4(9.9±1.6 mm Hg)were significantly decreased compare to control group(17.9±1.6 mm Hg) and group 2(16.6 ±2.8 mm Hg; n =8,P 【0.05). At P28, mean IOPs of groups 3(13.8±3.3 mm Hg)and group 4(10.6 ±2.0 mm Hg) were also significantly reduced compare to control group(19.4±2.3 mm Hg) and group 2(18.5 ±2.4 mm Hg; n =8, P 【0.05). Meanwhile mean IOP of group 4 is significantly decreased compared to group 3 at P28(n =8, P 【0.05). Survival analysis of functional filtration blub in all groups revealed the longest survival time in group 4(24.9±5.1d) compared to that in group 3(20.6 ±4.3d), group 2(15.0 ±5.2d) and control group(10.1±5.7d).CONCLUSION: Amniotic membrane loaded with 5-FuNPs may function as an effective anti-scarring implant and provides improved long-term surgical outcomes for experimental trabeculectomy in rabbits.

Effects of amniotic membrane transplantation on cytokines expression in chemically burned rat corneas

AIM: To investigate the effect of amniotic membrane transplantation (AMT) on the expressions of inflammatory-related, angiogenic-related and growth-related cytokines in rat corneas after chemical injury. METHODS: Alkali wounds were inflicted on the central corneas of rats by applying a round filter paper soaked in 1mol/L NaOH for 40 seconds. One week after alkali burn, 12 rats were randomly divided into 2 groups: the AMT group and the control group, and AMT was performed on the rats in the AMT group. Corneal opacity and neovascularization were observed by slit-lamp microscopy. The protein levels of interleukin (IL)-2, interferon (IFN)-gamma, IL-10 and transforming growth factor (TGF)-beta were determined by enzyme-linked immunosorbent assay 2 weeks after AMT. The mRNA levels of matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) were evaluated by real-time quantitative PCR. RESULTS: In the AMT group, the corneal opacity was improved (P =0.011) and the area of corneal neovascularization was significantly decreased (P=0.005) compared with the control group. The amount of IL-2 and IFN-gamma secreted by Th1 cells were decreased after AMT, whereas the amount of IL-10 and TGF-beta secreted by Th2 cells were increased ( P <0.05). The level of MMP-2 was significantly down-regulated (P=0.013) at the nnRNA level in the AMT group, while the expression of EGF was significantly higher (P= 0.022) compared with the control. CONCLUSION: AMT may suppress corneal neovascularization after chemical injury by modulating the expressions of soluble factors.

Homemade lyophilized cross linking amniotic sustained-release drug membrane with anti-scarring role after filtering surgery in rabbit eyes

AIM: To investigate the antifibrotic effect of the freeze-dried bilayered fibrin-binding amniotic membrane as a drug delivery system on glaucoma surgery in rabbit model. The aim of this study was to prepare a novel local delivery system for the sustained and controllable release of 5-Fu. METHODS: Twenty-four Japanese white rabbits were randomized into three groups: the experimental group (ocular trabeculectomy in combination with 5-Fu loaded freeze-dried bilayered fibrin-binding amniotic membrane transplantation), the control group (ocular trabeculectomy in combination with 5-Fu) and the blank group (single trabeculectomy). HE staining, massion staining and immunohistochemistry for alpha -SMA were performed on days 7, 14, 21 and 30 following surgery. The concentration of 5-Fu in rabbit aqueous humor was examined by high performance liquid chromatography (HPLC) 3 days after the surgery. RESULTS: Statistical differences were noted in intraocular pressure among groups on day 7, 14, 21 and 30 following surgery. Histology further demonstrated that trabeculectomy in combination with freeze-dried bilayered fibrin-binding amniotic membrane yielded well wound healing and no scar formation and was beneficial for long term effect. CONCLUSION: HPLC showed a good slow-release effect with freeze-dried bilayered fibrin-binding amniotic membrane.

Amniotic membrane welded to contact lens by 1470-nm diode laser:a novel method for sutureless amniotic membrane transplantation

AIM: To avoid the side effects of the suture usage by welding amniotic membrane(AM) to contact lens(CL)with laser.METHODS: AM was taken from pregnant women and cleaned from blood clots with sterile phosphate-buffered physiological saline solution which included antibiotics.Stromal side of the AM was spread inside of the CL and it was welded to CL by 1470 nm diode laser. And 600 μm diameter fiber tip of the laser was contacted with the epithelial side of the AM from 4 separate points. After welding excess amniotic membrane around the CL was cut with a scalpel.RESULTS: Stromal side of the AM was spread inside of the CL and then with laser fiber, different power levels and exposure times were applied on the epithelium of AM and 340 m W for seven seconds was found optimal.CL and AM attached with the spot welding effect in 4points by touching fiber tip. CL-AM welded complex did not separated from each other while holding AM that extend beyond the CL with the help of two forceps.CONCLUSION: As a conclusion, it was aimed in this study to achieve the success of the conventional amniotic membrane transplantation(AMT) with the easiness of applying a CL and to avoid risks and side effects of corneal or conjunctival suturing. The results showed that the application of the CL-AM complex will be as easy as the application of a CL and lasts shortly.

Comparison of viscoelasticity between normal human sciatic nerve and amniotic membrane

Sciatic nerve tissue was obtained from the gluteus maximus muscle segment of normal human cadavers and amniotic membrane tissue was obtained from healthy human puerperant placentas. Both tissues were analyzed for their stress relaxation and creep properties to determine suitability for transplantation applications. Human amniotic membrane and sciatic nerve tissues had similar tendencies for stress relaxation and creep properties. The stress value of the amniotic membrane stress relaxation group decreased to a greater extent compared with the sciatic nerve stress relaxation group. Similarly, the stress value of the amniotic membrane creep group increased to a greater extent compared with the sciatic nerve creep group. The stress relaxation curve for human amniotic membrane and sciatic nerve showed a logarithm correlation, while the creep curve showed an exponential correlation. These data indicate that amniotic membrane tissue has better stress relaxation and creep properties compared with sciatic nerve tissue.

Amniotic membrane for covering high myopic macular hole associated with retinal detachment following failed primary surgery

AIM:To evaluate the therapeutic effect of amniotic membrane(AM)for covering high myopic macular hole associated with retinal detachment following failed primary surgery.METHODS:Seventeen eyes of 17 patients whose axial length was more than 29 mm suffered from macular hole(MH)or MH associated with retinal detachment(RD),and had previously surgery of pars plana vitrectomy(PPV)with internal limiting membrane(ILM)peeling and silicone oil(SO)tamponade.Half a year after the surgery,optical coherence tomography(OCT)showed that MH did not heal in all 17 eyes and RD was still maintained in 13 eyes of these 17 eyes.We performed SO removal combined with AM covering on macular area and C3 F8 tamponade,and phacoemulsification combined with intraocular lens implantation simultaneously cataract eyes.We followed up these patients for one year.RESULTS:In all 17 eyes,SO was removed successfully,MHs were healed and RDs were reattached.One eye(5.89%,1/17)had AM shifted half a month after surgery and underwent a second surgery to adjust the position of the AM and supplement C3 F8.After surgery,the visual acuity(VA)improved in 15 eyes(88.24%,15/17),no change in two eyes(11.76%,2/17).No serious complications occurred in all eyes.CONCLUSION:AM covering is helpful to rescue the previous failure surgery of high myopic MH.