Fabrication and multiscale modeling of polycaprolactone/amniotic membrane electrospun nanofiber scaffolds for wound healing

BACKGROUND

Enhancing the efficiency of cell-based skin tissue engineering (TE) approaches is possible via designing electrospun scaffolds possessing natural materials like amniotic membrane (AM) with wound healing characteristics. Concentrating on this aim, we fabricated innovative polycaprolactone (PCL)/AM scaffolds through the electrospinning process.

METHODS

The manufactured structures were characterized by employing scanning electron microscope (SEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, tensile testing, Bradford protein assay, etc. In addition, the mechanical properties of scaffolds were simulated by the multiscale modeling method.

RESULTS

As a result of conducting various tests, it was concluded that the uniformity and distribution of fibers decreased with an increase in the amniotic content. Furthermore, PCL-AM scaffolds contained amniotic and PCL characteristic bands. In the case of protein release, greater content of AM led to the release of higher amounts of collagen. Tensile testing revealed that scaffolds' ultimate strength increased when the AM content augmented. The multiscale modeling demonstrated that the scaffold had elastoplastic behavior. In order to assess cellular attachment, viability, and differentiation, human adipose-derived stem cells (ASCs) were seeded on the scaffolds. In this regard, SEM and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays showed significant cellular proliferation and viability on the proposed scaffolds, and these analyses illustrated that higher cell survival and adhesion could be achieved when scaffolds possessed a larger amount of AM. After 21 days of cultivation, particular keratinocyte markers, such as keratin I and involucrin, were identified through utilizing immunofluorescence and real-time polymerase chain reaction (PCR) tests. The markers' expressions were higher in the PCL-AM scaffold with a ratio of 90:10 v v-1 compared with the PCL-epidermal growth factor (EGF) structure. Moreover, the presence of AM in the scaffolds resulted in the keratinogenic differentiation of ASCs even without employing EGF. Consequently, this state-of-the-art experiment suggests that the PCL-AM scaffold can be a promising candidate in skin bioengineering.

CONCLUSION

This study showed that mixing AM with PCL, a widely used polymer, in different concentrations can overcome PCL disadvantages such as high hydrophobicity and low cellular compatibility.

P30-A119 Microbial contamination of amniotic membrane

PURPOSE

This retrospective study aims to compare the rate of microbial contamination in fresh, non-preserved amniotic tissue as opposed to decontaminated cryopreserved tissue, thereby being able to determine the efficiency of the decontamination procedures applied during amniotic tissue preparation in the Cornea Bank Essen.

METHODS

The amniotic tissue was retrieved from donor placentas acquired through elective c-section. Tissue preparation was performed according to standard operation procedures of the Cornea Bank Essen. Briefly, the tissue is rinsed with sterile balanced salt solution (BSS) and decontaminated with BSS containing anti-infectives. Preservation included the application of a cryopreservation solution containing anti-infectives and glycerin. The tissue is stored at a temperature of -80°C. Screening for microbial contamination of amniotic tissue in its pre- and post decontamination status is part of the process.In this study, data from 107 placentas prepared in the eye bank were retrospectively evaluated for the microbiological status to determine the effectivity of the procedure.

RESULTS

Out of the fresh, non-preserved amniotic tissue, 53 were tested positive for microbial contamination. The most common species identified were C.acnes and Staphylococcus spp., which jointly comprised around 80% of the detected microorganisms. Others found in the remaining placentas were of the species: Acinetobacter, Bacillus spp., Faklamia, Lactobacillus, Rothia, Micrococcus, Penicillium, Ralstonia, Streptococcus and non-specific aerobic sporulating bacteria.In contrast, 8 samples of the decontaminated cryopreserved tissue were tested positive for microorganisms with 4 placentas inhabited by C.acnes, 2 by Bacillus spp. while the remaining consisting each of the species Staphyloccocus and Ralstonia.

CONCLUSION

Overall, the decontamination measures applied during the preparation of the amniotic tissue can be regarded as effective. We found a significant reduction of the number of microorganisms detected in the amniotic tissue following antibiotic administration.However, some of the remaining species identified in the processed samples may be considered as contamination during the preparation and testing procedures.For instance, C.acnes can be considered a result of secondary contamination due to incorrect handling. Species such as Bacillus most likely managed to endure the decontamination process owing to its natural resilience against harsh circumstances.

A preliminary report assessing the feasibility and effectiveness of amniotic bladder therapy in patients with chronic radiation cystitis

INTRODUCTION

Chronic radiation cystitis (CRC) can develop between 6 months and 20 years after radiation therapy that presents with symptoms of urinary frequency, urgency, bladder pain, and nocturia. Amniotic membrane (AM) is known to contain pro-regenerative properties and could thereby be a potential therapeutic modality for radiation-induced tissue injury of the bladder.

MATERIALS AND METHODS

CRC patients recalcitrant to previous treatments received amniotic bladder therapy (ABT) comprised of intra-detrusor injections of 100 mg micronized AM (Clarix Flo) diluted in 10 mL 0.9% preservative-free sodium chloride. Clinical evaluation and questionnaires (Interstitial Cystitis Symptom Index (ICSI), Interstitial Cystitis Problem Index (ICPI), Bladder Pain/ Interstitial Cystitis Symptom Score (BPIC-SS), Overactive Bladder (OAB) Assessment Tool, and SF-12 Health Survey) were repeated at preop and 2, 4, 8 and 12 weeks post-injection.

RESULTS

Five consecutive female patients aged 64.4 ± 20.1 years with a median CRC disease duration of 10 years were included. After ABT, BPIC-SS scores improved from baseline to 12 weeks (36.6 ± 1.1 to 12.6 ± 3.1) and this was associated with an improvement in ICSI, ICPI, OAB, and SF-12 scores. One patient had an acute urinary tract infection at 2 weeks but was successfully treated with oral antibiotics. No other adverse events related to micronized AM injections were observed. Uroflow assessments showed increases in voided volume for all five patients.

CONCLUSIONS

This data provides additional evidence for the potential benefit of ABT in patients with chronic inflammatory conditions of bladder such as CRC.

Evaluating the Clinical Application of Automatic Chromosome Harvesting for Prenatal Karyotype Analysis

Objective: The clinical value of an automatic chromosome harvester was evaluated, which included a comparison between the manual and automatic harvesting for the isolation of amniotic fluid cell chromosomes. Methods: Amniotic fluid samples from 96 high-risk gravida cases identified at 17-25 weeks treated at the Prenatal Diagnostic and Reproductive Center from June to July 2022 were collected. These samples underwent both manual and automatic chromosome collection, and their harvest time and number of amniotic cells were compared. These chromosomes were then used to produce karyotypic data for each sample using an automatic chromosomal karyotype analysis system, scan karyotype. Results: The average automatic harvesting time per sample, 3.92 min, was significantly lower than that of the manual harvesting, 7.89 min (p < 0.001). In addition, the average number of cells from the automatic harvesting (4.16 × 106 pieces) was significantly increased when compared with those of the manual group (2.10 × 106 pieces; p < 0.001). Further karyotyping revealed that both sets of chromosomes produced clear bands and good dispersion data, producing no significant differences in these evaluations (p > 0.05). However, the number of analyzable karyotypes obtained using the automatic harvester was significantly higher than those of the manual harvesting (p < 0.001). Conclusions: The automatic chromosome harvester can effectively save time, manual labor and consumables, harvest more analyzable karyotypes, and improve the efficiency of clinical diagnosis. The automatic chromosome harvester is highly stable and repeatable, which has the potential to help achieve large-scale standardized chromosome harvesting and is worthy of widespread clinical promotion.

Protecting human amnion and chorion matrices during processing: Performance enhancement in a diabetic mouse model and human co-culture system

Recent evidence suggests that protecting human amnion and chorion matrices (HACM) during processing enhances the performance of HACM for wound repair and tissue regeneration. We utilised a diabetic (db/db) delayed wound healing mouse model. Treatment of db/db full-thickness excisional wounds with HACM, processed with a polyampholyte preservative accentuated the proliferative phase of wound healing that decreased the time necessary to heal wounds. Polyampholyte protection improved the preservation of growth factors and cytokines during room temperature storage following E-beam sterilisation and improved its function in wound healing applications. Our findings indicate protected HACM tissue up-regulated MIP2, NF-kB, TNF-α, KI-67, and Arg1 (0.6-fold to 1.5-fold) but those changes were not statistically significant. Immunofluorescent assessment identifying cell activity illustrated an induction of the proliferative phase of wound healing and a switch from an inflammatory macrophage phenotype (M1) to a pro-regenerative macrophage phenotype (M2a). Genomic profiling of 282 genes was performed using Nanostring from co-cultures of human macrophages and fibroblasts. The polyampholyte + HACM-treated group, compared with the HACM or polyampholyte alone groups, had a statistically significant up-regulation (32-368 fold) of 12 genes primarily involved in macrophage plasticity including CLC7, CD209, CD36, HSD11B1, ICAM1, IL1RN, IL3RA, ITGAX, LSP1, and PLXDC2 (adj. p-value < 0.05). The polyampholyte alone group demonstrated statistically significant down-regulation of four genes ADRA2, COL7A1, CSF3, and PTGS2 (adj. p < 0.05). The HACM alone group up-regulated four genes ATG14, CXCL11, DNMT3A, and THBD, but the results were not statistically significant. Biomechanical measurements indicated that wounds treated with polyampholyte-protected HACM had more tensile integrity compared with wounds treated with HACM alone. These findings indicate that better protection of HACM during processing stabilises the HACM matrix, which may lead to improved wound healing outcomes.

Comparison of the Intrableb Characteristics of Anterior Segment Optical Coherence Tomography Imaging in Trabeculectomy according to Amniotic Membrane Transplantation

INTRODUCTION

The purpose of this study was to compare the characteristics of filtering bleb with anterior segment optical coherence tomography (AS-OCT) according to amniotic membrane transplantation (AMT).

METHODS

One hundred and sixteen eyes of 103 glaucoma patients who underwent trabeculectomy with (AMT group; 85 eyes) or without AMT (control group; 31 eyes) were included. Intrableb parameters were evaluated with AS-OCT. Surgical success was defined as an intraocular pressure (IOP) ≤18 mm Hg and IOP reduction ≥20% without medication at the time of AS-OCT examination. Logistic regression analyses were performed to determine factors associated with IOP control.

RESULTS

In the eyes with successful IOP control, the fluid-filled space area, score, and height were greater for the AMT group than the control group (all ps < 0.001), while stripping layer thickness was greater and bleb wall reflectivity was lower for the control group than the AMT group (all ps < 0.001). Surgical success in the AMT group was associated with greater fluid-filled space score, lower bleb wall reflectivity, and microcyst formation (odds ratio [OR] = 8.016, 0.913, and 16.202, respectively, all ps ≤ 0.041). Lower bleb wall reflectivity alone was associated with surgical success in the control group (OR = 0.815, p = 0.019).

CONCLUSION

The extent of the fluid-filled space was associated with successful IOP control after trabeculectomy with AMT. Hyporeflective bleb wall was associated with successful IOP control in AMT and control groups.

Human Amniotic Membrane Promotes Angiogenesis in an Oxidative Stress Chronic Diabetic Murine Wound Model

Objective: The development of animal models, which adequately replicate the pathophysiology of chronic wounds, has been challenging. In this study, we utilized an oxidative stress (OS) murine model, which was previously developed by our group, to study the effect of a human amniotic membrane (AM) on chronic wound healing. Approach: Forty-five diabetic (genetically obese leptin receptor-deficient mice [db/db]) mice were separated into three groups. Thirty mice received an OS regimen and a 1 - × 1 cm² full-thickness excisional dorsal wound. The wounds were either covered with AM and occlusive dressing (db/db^OS-AM) or occlusive dressing only (db/db^OS). Fifteen mice did not receive the OS regimen, and were covered with AM and occlusive dressing (db/db-AM). The wounds were photographed, and tissue was harvested at various time points. Results: Vascular density was higher in the AM-treated groups (db/db^OS-AM: 34 ± 12; db/db-AM: 37 ± 14; vs. db/db^OS: 19 ± 9 cluster of differentiation 31 [CD31⁺]/high power field [HPF] photograph; p = 0.04 and p = 0.003). Vessel maturity was lowest in the db/db^OS group (21% ± 4%; vs. db/db^OS-AM: 38% ± 10%, p = 0.004; db/db-AM: 40% ± 11%, p = 0.0005). Leukocyte infiltration was higher in the AM groups (db/db^OS-AM: 15 ± 4; db/db-AM: 16 ± 4 vs. db/db^OS: 8 ± 3 lymphocyte common antigen [CD45⁺]/HPF; p = 0.005 and p = 0.06). AM upregulated various proangiogenic factors, including vascular endothelial growth factor (VEGF), and downregulated genes involved in chronicity, such as osteopontin, as visualized through proteome analysis and western blotting. Cell death was lower in the AM groups (db/db^OS-AM: 28 ± 10, db/db-AM: 7 ± 5 vs. db/db^OS: 17% ± 9% Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling [TUNEL⁺]; p = 0.03 and p < 0.0001). Innovation: This study offers new insight on the mechanisms of action of human AM in chronic wound healing. Conclusion: AM treatment promoted healing in mice with complex chronic wounds. The AM stimulated angiogenesis through upregulation of proangiogenic factors, improving the wound milieu by increasing leukocyte and growth factor delivery and decreasing cell death.

Genetic amniocentesis using atraumatic 29 gauge needle in patients having a chorioamniotic separation

OBJECTIVES

Chorioamniotic separation (CAS) at the time of standard amniocentesis (AC) is a risk factor for postprocedural complications and should be avoided. The aim of this study was to quantify procedure-related risks after AC with a 29G-needle in cases of CAS, and evaluation of perinatal outcome in CAS after 15 weeks' gestation (GW).

METHODS

Retrospective analysis of genetic AC with a pencil-point 29G needle after 15 completed GW in pregnancies, in which the fetal membranes were not yet fused. Included into the study were women aged 16-44 years with at least 15 completed GWs referred for second trimester AC to identify fetal chromosomal aberrations.

RESULTS

437 ACs were made in total with the 29G-needle. The median maternal age was 30 (16-44) years. 145 cases showed CAS where the distance between chorion and amnion was 0.10-10.02 mm at AC. 38 pregnancies were terminated, 37 of which had a genetic disorder. The risk of aneuploidy increases by a factor of 2 (95% CI 1.4-2.8) for every 1 mm of CAS enlargement. No procedure-related complications were found up to two weeks after the AC.

CONCLUSIONS

CAS seems to be massively underreported. Early diagnosis in case of CAS is something to strive for as CAS could be an indicator of genetic abnormalities - a "soft marker". With the atraumatic 29G needle, the risk of complications after AC in CAS seems to be very low.

Biological nerve conduit model with de-epithelialized human amniotic membrane and adipose-derived mesenchymal stem cell sheet for repair of peripheral nerve defects

In this study, a biological conduit, consisting of an adipocyte-derived mesenchymal stem cell (AdMSCs) sheet and amniotic membrane (AM), was designed for the reconstruction of peripheral nerve defects. To evaluate the effect of the produced conduit on neural regeneration, a 10-mm sciatic nerve defect was created in rats, and experiments were carried out on six groups, i.e., sham control group (SC), negative control group (NC), nerve autograft group (NG), the biological conduit (AdMSCs + AM) group, the commercial PGA tube conduit (PGA) group, and the conduit only consisting of AM (AM) group. The effects of different nerve repair methods on the peripheral nerve and gastrocnemius muscle were evaluated by functional, histological, and immunohistochemical tests. When the number of myelinated axons was compared between the groups of AdMSCs + AM and PGA, it was higher in the AdMSCs + AM group (p < 0.05). The percentage of gastrocnemius collagen bundle area of AdMSCs + AM group was found to be statistically lower than the PGA group (p < 0.05). The muscle fiber diameter of AdMSCs + AM group was lower than that of the NG group, but significantly higher than that of the PGA group and the AM group (p < 0.001). Muscle weight index was significantly higher in the AdMSCs + AM group compared to the PGA group (p < 0.05). It was observed that nerve regeneration was faster in the AdMSCs + AM group, and there was an earlier improvement in pin-prick score and sciatic functional index compared to the PGA group and the AM group. In conclusion, the biological conduit prepared from the AdMSCs sheet and AM is regarded as a new biological conduit that can be used as an alternative treatment method to nerve autograft in clinical applications.

Amniotic Membrane Patching to Assist Closure of Recalcitrant Macular Holes

BACKGROUND AND OBJECTIVE

This study reports a case series of patients with persistent macular holes (MHs) who underwent human amniotic membrane subretinal placement to achieve successful anatomic MH closure.

PATIENTS AND METHODS

This was a retrospective case series of patients with persistently open full-thickness MHs who underwent human amniotic membrane placement. Patients were observed up to 6 months postoperatively.

RESULTS

Ten patients were included. The mean preoperative best-corrected visual acuity was 1.6 logMAR (20/800). Postoperatively, mean best-corrected visual acuity improved to 1.3 logMAR (20/400) at 1 month and 1.1 logMAR (20/250) by the 3- and 6-month visits. In all cases, the MH appeared closed at the 1-week visit and remained closed at their last follow-up. Optical coherence tomography showed closure in all cases. No adverse events were reported.

CONCLUSIONS

Human amniotic membrane sub-retinal placement may serve as a useful surgical technique to assist in the closure of recalcitrant macular holes. [Ophthalmic Surg Lasers Imaging Retina 2023;54(x):X-X.].

Hyperdry Human Amniotic Membrane as a Protective Dressing for Open Wounds With Exposed Bowel in Mice

INTRODUCTION

An enteroatmospheric fistula forms when the exposed bowel is perforated with chronic enteric fistula formation. Currently, there is no established preventative method for this condition. Hyperdry (HD) amniotic membrane (AM) can promote early granulation tissue formation on the exposed viscera and is suitable for dressing intractable wounds as it possesses anti-inflammatory, antibacterial, and immunomodulatory properties. This study investigated whether HD-AM promotes early formation of blood vessel-containing granulation tissue for enteroatmospheric fistula treatment.

METHODS

An experimental animal model of an open wound with exposed bowel was developed. A 15 × 20 mm wound was prepared on the abdomen of Institute of Cancer Research mice, and the HD-AM was placed. The mice were assigned to one of the following groups: HD-AM group, in which the stromal layer of the HD-AM was placed in contact with the exposed bowel; HD-AM UD group, in which the epithelial layer of the HD-AM was placed in contact with the exposed bowel; and the HD-AM (-) or control group, in which the HD-AM was not used.

RESULTS

On postoperative days 7 and 14, granulation tissue thickness significantly increased in the HD-AM and HD-AM UD groups compared with that in the HD-AM (-) group. Macrophages accumulated in the HD-AM epithelium only in the HD-AM group. During HD-AM contact, a subset of invading macrophages switched from M1 to M2 phenotype.

CONCLUSIONS

HD-AM is a practical wound dressing with its scaffolding function, regulation of TGF β-1 and C-X-C motif chemokine 5 (CXCL-5), and ability to induce M1-to-M2 macrophage conversion.

Human amniotic membrane graft for refractory macular hole: A single-arm meta-analysis and systematic review

PURPOSE

The treatment of refractory macular holes is controversial, with human amniotic membrane grafts emerging recently as an attractive option. We performed a meta-analysis and systematic review in this paper to assess the results of human amniotic membrane (hAM) in the treatment of refractory macular hole (MH).

METHODS

We searched the Cochrane Database of Systematic Reviews, Web of Science, PubMed, Embase, China National Knowledge Infrastructure databases, VIP database, Wanfang Data Knowledge Service Platform, Sinomed, Chinese Clinical Trial Registry, and Clinical Trials.gov. Studies reporting hAM for the treatment of refractory MH were included. The outcomes are MH closure rate, visual acuity (VA) improvement rate, and graft dislocation/contracture rate.

RESULTS

A total of 8 studies on 103 eyes were included, all of which had undergone failed vitrectomy and internal limiting membrane (ILM) peeling. In all studies, the VA improvement rate was 66% (95%CI: 45 to 84%), the MH closure rate was 94% (95%CI: 84 to 100%) and the hAM graft dislocation/contracture rate was 6% (95%CI: 0 to 15%). In the studies using cryopreserved hAM grafts, the MH closure rate was 99% (95%CI: 94 to 100%) and the hAM graft dislocation/contracture rate was 3% (0%, 10%). The VA improvement rates were 94% (95%CI: 79 to 100%) in the retinal detachment subgroup, 37% (95%CI: 20 to 56%) in the pathologic myopia subgroup, and 62% (95%CI: 14 to 100%) in the idiopathic MH subgroup.

CONCLUSION

Human amniotic membrane in the treatment of refractory MH results in visual improvement. It has a high macular hole closure rate and low dislocation/contracture rate. Cryopreserved hAM grafts might have better outcomes than dehydrated grafts.

Cryopreserved amniotic membrane in the treatment of limb skin defects of aplasia cutis congenita: a case study

OBJECTIVE

To report the efficacy and long-term outcomes of treating the skin defects of aplasia cutis congenita (ACC) with cryopreserved amniotic membrane (AM).

METHOD

Human amnion was obtained from the caesarean delivery of a full-term healthy pregnancy and processed in a sterile laminar flow hood, and cryopreserved in liquid nitrogen. The structure of the AM was investigated histologically and the viability of the epithelial cells was assessed after cryopreservation and compared with fresh AM and with AM preserved in phosphate-buffered saline (PBS) at 4°C. The cryopreserved AM was applied onto the lower limb skin defects of a one-month old baby with ACC. Timely AM changes were performed as necessary until the wounds healed.

RESULTS

The structure of the cryopreserved AM was intact, with little visible difference compared with fresh AM. The viability of the epithelial cells was partially lost but still much better retained than in those preserved in PBS at 4°C. The limb skin defects were gradually re-epithelialised upon application of the AM and were completely healed after one month. The 4-month and 2-year follow-ups presented good skin texture and colour, without hypertrophic scar formation.

CONCLUSION

In this case study, cryopreservation of AM presented a well preserved stromal compartment and viable epithelial layer. It also offered features such as pain relief, good attachment and adhesiveness, improved wound healing and suppressed scar formation in the treatment of ACC skin defects.

Mapping of the Human Amniotic Membrane: In Situ Detection of Microvesicles Secreted by Amniotic Epithelial Cells

The potential clinical applications of human amniotic membrane (hAM) and human amniotic epithelial cells (hAECs) in the field of regenerative medicine have been known in literature since long. However, it has yet to be elucidated whether hAM contains different anatomical regions with different plasticity and differentiation potential. Recently, for the first time, we highlighted many differences in terms of morphology, marker expression, and differentiation capabilities among four distinct anatomical regions of hAM, demonstrating peculiar functional features in hAEC populations. The aim of this study was to investigate in situ the ultrastructure of the four different regions of hAM by means of transmission electron microscopy (TEM) to deeply understand their peculiar characteristics and to investigate the presence and localization of secretory products because to our knowledge, there are no similar studies in the literature. The results of this study confirm our previous observations of hAM heterogeneity and highlight for the first time that hAM can produce extracellular vesicles (EVs) in a heterogeneous manner. These findings should be considered to increase efficiency of hAM applications within a therapeutic context.

Amniotic membrane attenuates heterotopic ossification following high-dose bone morphogenetic protein-2 treatment of segmental bone defects

Treatment of large bone defects with supraphysiological doses of bone morphogenetic protein-2 (BMP-2) has been associated with complications including heterotopic ossification (HO), inflammation, and pain, presumably due to poor spatiotemporal control of BMP-2. We have previously recapitulated extensive HO in our rat femoral segmental defect model by treatment with high-dose BMP-2 (30 μg). Using this model and BMP-2 dose, our objective was to evaluate the utility of a clinically available human amniotic membrane (AM) around the defect space for guided bone regeneration and reduction of HO. We hypothesized that AM surrounding collagen sponge would attenuate heterotopic ossification compared with collagen sponge alone. In vitro, AM retained more BMP-2 than a synthetic poly(ε-caprolactone) membrane through 21 days. In vivo, as hypothesized, the collagen + AM resulted in significantly less heterotopic ossification and correspondingly, lower total bone volume (BV), compared with collagen sponge alone. Although bone formation within the defect was delayed with AM around the defect, by 12 weeks, defect BVs were equivalent. Torsional stiffness was significantly reduced with AM but was equivalent to that of intact bone. Collagen + AM resulted in the formation of dense fibrous tissue and mineralized tissue, while the collagen group contained primarily mineralized tissue surrounded by marrow-like structures. Especially in conjunction with high doses of growth factor delivered via collagen sponge, these findings suggest AM may be effective as an overlay adjacent to bone healing sites to spatially direct bone regeneration and minimize heterotopic ossification.

Multi-Lineage Human Endometrial Organoids on Acellular Amniotic Membrane for Endometrium Regeneration

Asherman's syndrome is an endometrial regeneration disorder resulting from injury to the endometrial basal layer, causing the formation of scar tissue in the uterus and cervix. This usually leads to uterine infertility, menstrual disorders, and placental abnormalities. While stem cell therapy has shown extensive progress in repairing the damaged endometrium and preventing intrauterine adhesion, issues of low engraftment rates, rapid senescence, and the risk of tumorigenesis remain to be resolved for efficient and effective application of this technology in endometrial repair. This study addressed these challenges by developing a co-culture system to generate multi-lineage endometrial organoids (MLEOs) comprising endometrial epithelium organoids (EEOs) and endometrial mesenchymal stem cells (eMSCs). The efficacy of these MLEOs was investigated by seeding them on a biocompatible scaffold, the human acellular amniotic membrane (HAAM), to create a biological graft patch, which was subsequently transplanted into an injury model of the endometrium in rats. The results indicated that the MLEOs on the HAAM patch facilitated endometrial angiogenesis, regeneration, and improved pregnancy outcomes. The MLEOs on the HAAM patch could serve as a promising strategy for treating endometrial injury and preventing Asherman's syndrome.

Management of XEN Gel Stent Exposure with Conjunctival Erosion via Rotational Conjunctival Flap and Amniotic Membrane Transplantation—A Case Report

Background: Despite its proven effectiveness and safety profile, the XEN gel stent (Allergan Inc., CA, USA) for minimally invasive glaucoma surgery (MIGS) has a probability of postoperative complications, including postoperative hypotony, hyphema, stent migration, stent obstruction, bleb fibrosis, and fibrin formation. In particular, the use of adjunctive Mitomycin-C (MMC) might be associated with bleb-related complications, including conjunctival erosion, XEN gel stent exposure, and blebitis. However, there are few studies on XEN gel stent exposure and its management. We describe a case of XEN gel stent exposure with conjunctival erosion 18 months postoperatively, which resolved effectively after combination treatment with a rotational conjunctival flap and amniotic membrane transplantation. Case presentation: A 74-year-old Korean male patient with diabetes and hypertension underwent uncomplicated ab interno XEN gel stent implantation with a subconjunctival injection of 0.1 cc of 0.02% MMC and presented with low intraocular pressure (IOP) with a well-functioning filtering bleb. Periocular pain and tearing developed 18 months after the initial operation, with mild deterioration of visual acuity to 20/100. Despite conservative medical treatment, the conjunctival erosion was not relieved. Anterior segment optical coherence tomography (AS-OCT) revealed an exposed XEN gel stent with conjunctival erosion. We performed bleb revision surgery using a rotational conjunctival flap and amniotic membrane transplantation. Slit-lamp examination and AS-OCT showed a well-formed moderate bleb without leakage, and IOP continued to be well controlled (14 mm Hg with latanoprost) until six months after bleb revision. Conclusions: This case report highlights the importance of careful examination, including slit-lamp examination, the Seidel test, and AS-OCT, to identify accurate anatomical positioning and to monitor ocular surface changes after XEN gel stent implantation with MMC or 5-FU. Combination treatment (rotational conjunctival flap and amniotic membrane transplantation) may be relatively safe for persistent XEN gel stent exposure.

Amniotic membrane extract-enriched hydrogel augments the therapeutic effect of menstrual blood-derived stromal cells in a rat model of intrauterine adhesion

We previously demonstrated that transplantation of menstrual blood-derived stromal cells (MenSCs) is a safe and effective therapy for treating intrauterine adhesions (IUA). However, improving the colonization and therapeutic efficiency of MenSCs is still needed before full clinical application. Here, we established an amniotic membrane extract (AME)-enriched RGD hydrogel, and evaluated the therapeutic effect of this adjuvant combined with MenSCs transplantation in an IUA rat model. Our results indicated that AME promoted the proliferation and secretion of MenSCs in vitro, up-regulated the expression of apoptosis-suppressing gene BCL2 and down-regulated the expression of apoptosis-related genes Caspase-3 and Caspase-8. The AME-enriched hydrogel was biocompatible, and improved the survival of MenSCs in vitro and in vivo. It also promoted the retention of MenSCs in IUA uterus and augmented the effects of MenSCs on improving uterus morphology, endometrial proliferation, endometrial receptivity and fibrosis suppression. In addition, co-transplantation of MenSCs with AME-enriched hydrogel markedly down-regulated the expressions of inflammation-related genes IL10 and TGFβ while up-regulated the IL4/IFN-γ ratio in the IUA endometrium, and improved the expressions of cell proliferation-related antigen, gland-regeneration-related marker leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), angiogenesis-related marker platelet and endothelial cell adhesion molecule 1 (PECAM1), endometrial receptivity related genes ITGα5 and ITGβ3. Our study suggested that AME and MenSCs had a synergistic effect. Co-transplantation of MenSCs with AME-enriched hydrogel provided a promising approach for stem cell-based IUA treatment.

Treatment of recurrent high myopic macular hole associated with retinal detachment using a human amniotic membrane

PURPOSE

To determine the efficacy of using a human amniotic membrane to close macular hole retinal detachment in highly myopic eyes.

STUDY DESIGN

Prospective, consecutive, nonrandomized interventional study.

METHODS

We included 19 high myopic eyes from 19 patients affected by macular hole retinal detachment who had already undergone vitrectomy with internal limiting membrane peeling. The patients underwent vitrectomy with amniotic membrane transplant.

RESULTS

Primary success was achieved after 3 months in 89.5% (17 of 19 eyes) and final macular hole closure was obtained in 94.7% (18 of 19 eyes) of the patients. The final retinal reattachment rate was 100%. The final 12-month mean BCVA improved from 20/2000 (2 logMAR) to 20/250 (1.1 logMAR). OCT-angiography revealed a high correlation between the superficial and deep capillary plexus and the final BCVA.

CONCLUSION

Human amniotic membrane patches can effectively repair macular hole retinal detachment in high myopic eyes in terms of anatomic results and BCVA recovery.

Microgel culture and spatial identity mapping elucidate the signalling requirements for primate epiblast and amnion formation

The early specification and rapid growth of extraembryonic membranes are distinctive hallmarks of primate embryogenesis. These complex tasks are resolved through an intricate combination of signals controlling the induction of extraembryonic lineages and, at the same time, safeguarding the pluripotent epiblast. Here, we delineate the signals orchestrating primate epiblast and amnion identity. We encapsulated marmoset pluripotent stem cells into agarose microgels and identified culture conditions for the development of epiblast- and amnion-spheroids. Spatial identity mapping authenticated spheroids generated in vitro by comparison with marmoset embryos in vivo. We leveraged the microgel system to functionally interrogate the signalling environment of the post-implantation primate embryo. Single-cell profiling of the resulting spheroids demonstrated that activin/nodal signalling is required for embryonic lineage identity. BMP4 promoted amnion formation and maturation, which was counteracted by FGF signalling. Our combination of microgel culture, single-cell profiling and spatial identity mapping provides a powerful approach to decipher the essential cues for embryonic and extraembryonic lineage formation in primate embryogenesis.

Amniotic membrane transplantation for acute ocular burns

BACKGROUND

Ocular surface burns can be caused by chemicals (alkalis and acids) or direct heat. One effect of the burn is damage to the limbal epithelial stem cells of the ocular surface with delayed re-epithelialisation, stem cell failure, and conjunctivalisation of the cornea. Amniotic membrane transplantation (AMT) performed in the acute phase (day 0 to day 7) following an ocular surface burn is claimed to reduce pain and accelerate healing. The surgery involves securing a layer of amniotic membrane (AM) to the eyelid margins as a patch to cover the entire ocular surface. However, there is debate about the severity of an ocular burn that may benefit from AMT and uncertainty of whether AMT improves outcomes.

OBJECTIVES

To compare the effect of AMT with medical therapy in the first seven days after an ocular surface burn, compared to medical therapy alone.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2021, Issue 9); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 29 September 2021.

SELECTION CRITERIA

We included randomised trials that compared an AMT applied in the first seven days following an ocular surface burn in addition to medical therapy with medical therapy alone. The outcome measures were failure of re-epithelialisation by day 21 post injury, visual acuity at final follow-up, corneal neovascularisation, symblepharon, time to re-epithelialisation and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, assessed the included studies for risk of bias and extracted relevant data. We contacted trial investigators for missing information. We summarised data using risk ratios (RRs) and mean differences (MDs) as appropriate.

MAIN RESULTS

We analysed two RCTs, but excluded individual patients who had been treated outside the acute phase in one of the studies (data provided by study authors). In total, 36 moderate burns from one RCT and 92 severe burns from two RCTs were evaluated separately. For both categories, the certainty of the evidence was downgraded principally as a result of high risks of performance and detection biases, and because of imprecision indicated by very wide confidence intervals. In addition, follow-up was insufficiently frequent to calculate time-to-epithelialisation precisely. Moderate severity ocular burns (Roper-Hall classification II-III) The relative risk of AMT on failure of epithelialisation by day 21 was 0.18 (0.02 to 1.31), and LogMAR visual acuity was 0.32 lower (0.55 to 0.09 lower) in the treatment group (i.e. better), suggesting a possible benefit of AMT. The GRADE assessment for failure of epithelialisation by day 21 was downgraded to very low due to the risk of bias and imprecision (very wide confidence intervals including no effect). The GRADE assessment for visual acuity at final follow-up was downgraded to low due to the risk of bias and imprecision (optimal information size not met). The relative effects of AMT on corneal neovascularisation (RR 0.56; 0.21 to 1.48), symblepharon (RR 0.41; 0.02 to 9.48) and time-to-epithelialisation (13 days lower; 26.30 lower to 0.30 higher) suggest possible benefit of AMT, but the wide confidence intervals indicate that both harm and benefit are possible. GRADE assessments for these outcomes were once again downgraded to very low due to the risk of bias and imprecision. Since adverse effects are rare, the small sample would have fewer occurrences of rare but potentially important adverse effects. The GRADE assessment for adverse effects was therefore considered to be low.  Severe ocular burns (Roper-Hall classification IV) The relative risk of AMT on failure of epithelialisation by day 21 was 1.03 (0.94 to 1.12), and LogMAR visual acuity was 0.01 higher (0.29 lower to 0.31 higher) in the treatment group (i.e, worse), indicating no benefit of AMT. GRADE assessments for failure of epithelialisation by day 21 and final outcomes were downgraded to low. The relative effects of AMT on corneal neovascularisation (RR 0.84; 0.66 to 1.06), symblepharon (RR 0.89; 0.56 to 1.42) and time-to-epithelialisation (1.66 days lower; 11.09 lower to 7.77 higher) may include both benefit and harm. GRADE assessments for corneal neovascularisation, symblepharon and time-to-epithelialisation were downgraded to low due to risk of bias and imprecision. For adverse effects, the GRADE assessment was downgraded to low, reflecting the small sample sizes in the RCTs.

AUTHORS' CONCLUSIONS

There is uncertain evidence to support the treatment of moderate acute ocular surface burns with AMT in addition to standard medical therapy as a means of preventing failure of epithelialisation by day 21, improving visual outcome and reducing corneal neovascularisation, symblepharon formation and time-to-epithelialisation. For severe burns, the available evidence does not indicate any significant benefit of treatment with AMT.

Amniotic Membrane Enhances the Characteristics and Function of Stem Cell-Derived Retinal Pigment Epithelium Sheets by Inhibiting the Epithelial-Mesenchymal Transition

Human pluripotent stem cell-derived retinal pigment epithelium (iRPE) is an attractive cell source for disease modeling and cell replacement therapy of retinal disorders with RPE defects. However, there are still challenges to develop appropriate culture conditions close to in vivo microenvironment to generate iRPE sheets, which mimic more faithfully the characteristics and functions of the human RPE cells. Here, we developed a simple, novel platform to construct authentic iRPE sheets using human amniotic membrane (hAM) as a natural scaffold. The decellularized hAM (dAM) provided a Bruch's membrane (BM)-like bioscaffold, supported the iRPE growth and enhanced the epithelial features, polarity distribution and functional features of iRPE cells. Importantly, RNA-seq analysis was performed to compare the transcriptomes of iRPE cells cultured on different substrates, which revealed the potential mechanism that dAM supported and promoted iRPE growth was the inhibition of epithelial mesenchymal transition (EMT). The tissue-engineered iRPE sheets survived and kept monolayer when transplanted into the subretinal space of rabbits. All together, our results indicate that the dAM imitating the natural BM allows for engineering authentic human RPE sheets, which will provide valuable biomaterials for disease modeling, drug screening and cell replacement therapy of retinal degenerative diseases. STATEMENT OF SIGNIFICANCE: : Engineered RPE sheets have a great advantage over RPE cell suspension for transplantation as they support RPE growth in an intact monolayer which RPE functions are dependent on. The substrates for RPE culture play a critical role to maintain the physiological functions of the RPE in stem cell therapies for patients with retinal degeneration. In this study, we constructed engineered iRPE sheets on the decellularized human amniotic membrane (dAM) scaffolds, which contributed to enhancing epithelial features, polarity distribution and functional features of iRPE. dAM exhibited the ability of anti-epithelial mesenchymal transition (EMT) to support iRPE growth. Furtherly, the results of transplanted in vivo demonstrated the feasibility of iRPE sheets in retina regenerative therapy. Engineering RPE sheets on dAM is a promising strategy to facilitate the development of iRPE replacement therapy and retinal disease modeling.

Lack of Neuroprotection with a Single Intravenous Infusion of Human Amnion Epithelial Cells after Severe Hypoxia–Ischemia in Near-Term Fetal Sheep

Background: Hypoxic–ischemic encephalopathy (HIE) around the time of birth results from loss of oxygen (hypoxia) and blood supply (ischemia). Exogenous infusion of multi-potential cells, including human amnion epithelial cells (hAECs), can reduce hypoxic–ischemic (HI) brain injury. However, there are few data on treatment of severe HI in large animal paradigms at term. The aim of the current study was to determine whether infusion of hAECs early after injury may reduce brain damage after ischemia in near-term fetal sheep. Methods: Chronically instrumented fetal sheep (0.85 gestation) received 30 min of global cerebral ischemia followed by intravenous infusion of hAECs from 2 h after the end of ischemia (ischemia-hAEC, n = 6) or saline (ischemia-vehicle, n = 7). Sham control animals received sham ischemia with vehicle infusion (sham control, n = 8). Results: Ischemia was associated with significant suppression of EEG power and spectral edge frequency until the end of the experiment and a secondary rise in cortical impedance from 24 to 72 h, which were not attenuated by hAEC administration. Ischemia was associated with loss of neurons in the cortex, thalamus, striatum and hippocampus, loss of white matter oligodendrocytes and increased microglial numbers in the white matter, which were not affected by hAEC infusion. Conclusions: A single intravenous administration of hAECs did not reduce electrographic or histological brain damage after 30 min of global cerebral ischemia in near-term fetal sheep.

[Multidisciplinary regenerative treatment and mechanisms for rescuing a severe calciphylaxis patient with human amnion-derived mesenchymal stem cells]

Calciphylaxis is a rare disease with severe pain and high-mortality due to cutaneous ischemic necrosis and infection that currently lacks proved effective therapies. The occurrence of calciphylaxis in end stage kidney disease (ESKD) patients is known as calcific uremic arteriolopathy (CUA), which is characterized histologically by dermal microvessel calcification, intimal fibroplasia and microthrombosis. Here we innovatively treated a severe CUA patient with human amnion-derived mesenchymal stem cells (hAMSCs). A 34-year-old uremic woman was presented with progressive, painful malodorous ulcers in buttocks and mummified lower limbs. Skin pathological features supported the diagnosis of calciphylaxis. The patient was refractory to conventional multidisciplinary symptomatic therapies. With the approval of our hospital ethics committee, she was treated with hAMSCs including intravenous and local intramuscular injection, and external application of hAMSC culture supernatant to the wound area. During 15-month follow-up, the patient had regeneration of skin and soft tissues, with improved blood biochemical, inflammatory, mineral and bone metabolic indices and immunoregulation effects. After 15-month hAMSC treatment, the score of pain visual analog scale (VAS) decreased from 10 to 0, Bates-Jensen wound assessment tool (BWAT) score decreased from 65 to 13, and wound-quality of life (Wound-QoL) questionnaire score decreased from 68 to 0. We propose that hAMSC treatment is promising for CUA patients. The therapy is potentially involved in the multiple beneficial effects of inhibiting vascular calcification, stimulating angiogenesis and myogenesis, modulating adverse inflammatory and immunologic responses, promoting re-epithelialization and restoring skin integrity.

Anti-Arthritogenic Property of Interleukin 10-Expressing Human Amniotic MSCs Generated by Gene Editing in Collagen-Induced Arthritis

Although stem cells are promising tools for the treatment of arthritis, their therapeutic effects remain controversial. In this study, we investigated the therapeutic properties of interleukin (IL)-10-overexpressing human amniotic mesenchymal stem cells (AMMs) generated via gene editing in a collagen-induced mouse model. IL-10 was inserted into the genomic loci of AMMs via transcription activator-like effector nucleases. In vitro immunomodulatory effects of IL-10-overexpressing AMMs (AMM/I) were evaluated and their anti-arthritogenic properties were determined in collagen-induced arthritis (CIA) mice. Transplantation of AMM/I attenuates CIA progression. In addition, the regulatory T cell population was increased, while T helper-17 cell activation was suppressed by AMM/I administration in CIA mice. Consistently, AMM/I injection increased proteoglycan expression, while reducing inflammation and the expression levels of the pro-inflammatory factors, IL-1 β, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor- α, in joint tissues. In conclusion, use of IL-10-edited human AMM/I may be a novel therapeutic strategy for the treatment of arthritis.