Suppression of inflammatory and fibrotic responses in allergic inflammation by the amniotic membrane stromal matrix

The Regenerative Capacity of Tissue-Engineered Amniotic Membranes

Scaffolds can be introduced as a source of tissue in reconstructive surgery and can help to improve wound healing. Amniotic membranes (AMs) as scaffolds for tissue engineering have emerged as promising biomaterials for surgical reconstruction due to their regenerative capacity, biocompatibility, gradual degradability, and availability. They also promote fetal-like scarless healing and provide a bioactive matrix that stimulates cell adhesion, migration, and proliferation. The aim of this study was to create a tissue-engineered AM-based implant for the repair of vesicovaginal fistula (VVF), a defect between the bladder and vagina caused by prolonged obstructed labor. Layers of AMs (with or without cross-linking) and electrospun poly-4-hydroxybutyrate (P4HB) (a synthetic, degradable polymer) scaffold were joined together by fibrin glue to produce a multilayer scaffold. Human vaginal fibroblasts were seeded on the different constructs and cultured for 28 days. Cell proliferation, cell morphology, collagen deposition, and metabolism measured by matrix metalloproteinase (MMP) activity were evaluated. Vaginal fibroblasts proliferated and were metabolically active on the different constructs, producing a distributed layer of collagen and proMMP-2. Cell proliferation and the amount of produced collagen were similar across different groups, indicating that the different AM-based constructs support vaginal fibroblast function. Cell morphology and collagen images showed slightly better alignment and organization on the un-cross-linked constructs compared to the cross-linked constructs. It was concluded that the regenerative capacity of AM does not seem to be affected by mechanical reinforcement with cross-linking or the addition of P4HB and fibrin glue. An AM-based implant for surgical repair of internal organs requiring load-bearing functionality can be directly translated to other types of surgical reconstruction of internal organs.

Applications of Human Amniotic Membrane Patching Assisted Vitrectomy in the Management of Postoperative PVR in Complex Retinal Detachments

Human amniotic membranes (hAMs) are extraembryonic tissues currently employed in the treatment of many ocular and systemic diseases. Several reports indicate that hAMs can suppress the signaling pathway of tissue growth factor beta (TGF-β), a cytokine that plays a major role in the pathogenesis of proliferative vitreoretinopathy (PVR) through the induction of epithelial-mesenchymal transition (EMT) in exposed retinal pigmented epithelium (RPE) cells. The present study was conducted to evaluate the efficacy of a modified vitrectomy procedure (hAMP-V) involving the extensive coverage of exposed RPE with hAM patches to prevent postoperative PVR in a series of 15 cases of retinal detachment complicated by severe preoperatory PVR. The primary outcome was to assess the rate of successful retinal reattachment of a single hAMP-V procedure at 6 months from silicone oil removal. Secondary outcomes included the collection of intraoperative data concerning the quantity, size, and scope of hAM patches, and the assessment of postoperative improvements in mean LogMar BCVA at 3 and 6 months. Successful retinal reattachment was obtained in 14 out of 15 eyes (93.3%). Surgical failure due to major recurrence of PVR occurred in 1 out of 15 eyes (6.7%). Postoperative improvements in mean LogMar BCVA were statistically significant (p < 0.05, paired t-test). No intraoperative and postoperative adverse effects were reported. The study helped to refine the surgical technique while also offering cues for future improvements.

Orthobiologic Use in Sports Injuries

Orthobiologics have gained much popularity in recent years but there has not been a large amount of clinical evidence to support their use. In the limited research that has been published, they have been shown to be effective and safe. They can assist in earlier return to activity with the avoidance of surgery. They can also augment current surgical practice to aid in healing and return to sport with few complications. With new medical innovation, there is unfortunately a higher cost for these products. The use of orthobiologics will only grow and so will the need for high-level clinical evidence.

Sutureless Lyophilized Amniotic Membrane Grafting for Corneal Epithelial Defects

OBJECTIVES

To report the tolerability, safety, and efficacy of the lyophilized amniotic membrane (AM) Visio-AMTRIX placed under a bandage contact lens (BCL) in treating persistent epithelial defects (PEDs).

METHODS

This retrospective study included consecutive patients with PEDs treated with a lyophilized AM placed under the BCL. Patients with PEDs who did not respond to medical treatment were included. Patients with a follow-up time less than 3 months were excluded.

RESULTS

Eleven eyes of 11 patients (mean age, 61.6±15.9 years) were included. Time from PED presentation to AM transplantation (AMT) was 27.7±4.9 days, with the mean PED area of 13.2±11.3 mm2. Complete resolution was achieved in 8 of 11 eyes after a single AM graft. The epithelial defect persisted after the first AMT in three eyes (27.3%), and a second graft was necessary to achieve complete healing. The corneal epithelial defect healed in an average of 11.0±4.4 days after grafting. After PED resolution, the best-corrected visual acuity significantly improved from 0.66±0.30 logMAR (20/91 Snellen) to 0.58±0.24 logMAR (20/77 Snellen) (P=0.036) compared with baseline. The AM resorbed within 2 weeks in all cases. No complication or recurrence was observed.

CONCLUSIONS

A sutureless lyophilized AM under the BCL can resolve PEDs with a significant improvement in vision.

Development of a decellularized human amniotic membrane-based electrospun vascular graft capable of rapid remodeling for small-diameter vascular applications

The performance of small-diameter vascular grafts adapted to vascular replacement is commonly hindered by stenosis. To address this issue, a graft featuring rapid remodeling with degradation is warranted. In this work, a 1.8-mm-diameter graft was constructed by fabricating a decellularized human amniotic membrane (HAM) with polycaprolactone (PCL)/silk fibroin (SF) around it through electrospinning, namely, an HPS graft, and applied in a rat aortic grafting model for comparison to a decellularized porcine small intestinal submucosa (SIS)-integrated PCL/SF (SPS) graft and an autologous aorta. In vitro studies demonstrated that HAM provided a bioactive milieu for rapid endothelial cell proliferation and resisting fibroblast-induced collagen secretion. PCL/SF provides a biocompatible microenvironment for cellular infiltration with mechanical properties resembling those of the rat aorta. In vivo studies showed that the HPS graft induced functional endothelialization more rapidly, along with less intensive ECM deposition than the SPS graft upon the histologically weaker inflammatory response and foreign body reaction 4 weeks after implantation, and maintained patency by progressively stabilizing the remodeling structure approximating the native counterparts over 24 weeks. The bioengineered graft expands the applicability of allogeneic matrices with degradable electrospun polymers for long-term in situ vascular applications. STATEMENT OF SIGNIFICANCE: An orchestrated remodeling of the vascular graft, featuring rapid endothelialization and resisting extracellular matrix (ECM) deposition on the luminal surface, with a mechanically stable structure, is requisite for long-term vascular patency. Nevertheless, off-the-shelf grafts might not fulfil the criteria under abdominal aortic pressure. Herein, we fabricated a 1.8-mm-diameter vascular graft through the integration of a decellularized human amniotic membrane (HAM) with electrospun polycaprolactone (PCL)/silk fibroin (SF). In a rat aortic grafting model, the graft is capable of rapid endothelialization and resisting collagen deposition and provides a native-like mechanical structure for stabilizing the remodeling process towards that of the native aorta. This bioengineered graft has potential for small-diameter vascular regeneration, and provides advanced strategies to facilitate full-remodeling tissue applications.

Perinatal derivatives: How to best characterize their multimodal functions in vitro. Part C: Inflammation, angiogenesis, and wound healing

Perinatal derivatives (PnD) are birth-associated tissues, such as placenta, umbilical cord, amniotic and chorionic membrane, and thereof-derived cells as well as secretomes. PnD play an increasing therapeutic role with beneficial effects on the treatment of various diseases. The aim of this review is to elucidate the modes of action of non-hematopoietic PnD on inflammation, angiogenesis and wound healing. We describe the source and type of PnD with a special focus on their effects on inflammation and immune response, on vascular function as well as on cutaneous and oral wound healing, which is a complex process that comprises hemostasis, inflammation, proliferation (including epithelialization, angiogenesis), and remodeling. We further evaluate the different in vitro assays currently used for assessing selected functional and therapeutic PnD properties. This review is a joint effort from the COST SPRINT Action (CA17116) with the intention to promote PnD into the clinics. It is part of a quadrinomial series on functional assays for validation of PnD, spanning biological functions, such as immunomodulation, anti-microbial/anti-cancer activities, anti-inflammation, wound healing, angiogenesis, and regeneration.

Cytokine profile in tear and aqueous humor of primary open-angle patients as a prognostic factor for trabeculectomy outcome

OBJECTIVE

To evaluate the cytokine profile in tear and aqueous humor in primary open-angle glaucoma before trabeculectomy and correlate preoperative cytokine levels with the surgical outcome.

METHODS

Prospective study. Twenty-nine patients with primary open-angle glaucoma undergoing primary trabeculectomy were included. Levels of 27 cytokines were measured in tear an aqueous humor using the Bio-Plex Pro Human Cytokine 27-Plex Immunoassay kit (Bio-Rad Laboratories, Hercules, CA, USA).

RESULTS

29 patients who underwent trabeculectomy were included and their first-year follow-up visits were recorded. Mean age was 76.0 ± 7.0 years (range 56-84), mean intraocular pressure was 18.2 ± 3.6 mmHg and mean number of topical medications was 2.3 ± 0.9. At the one-year visit, 5 patients were classified as surgical failure. In aqueous humor, preoperative cytokine levels of regulated on activation normal T cell expressed and secreted (RANTES) were significantly higher in those patients with surgical failure at one year. IL-8 in tear and interferon gamma-induced protein (IP-10) in aqueous humor correlated positively with one-year IOP reduction. No statistically significant correlations were found with changes in visual field mean defect or global peripapillary retinal nerve fiber layer thickness (all, p >0.05).

CONCLUSIONS

Preoperative RANTES levels in aqueous humor as well as other cytokines could serve as useful biomarkers for trabeculectomy outcome.

Tailoring electrospun mesh for a compliant remodeling in the repair of full-thickness abdominal wall defect - The role of decellularized human amniotic membrane and silk fibroin

Tailored electrospun meshes have been increasingly explored for abdominal wall defect repair in preclinical and clinical studies. However, the fabrication of a bioengineered mesh adapts to the intraperitoneal repair for a compliant remodeling remains a great challenge. In this study, we fabricated a functional mesh by combining polycaprolactone (PCL) with silk fibroin (SF) and decellularized human amniotic membrane (HAM) proportionally via electrospinning. SF was integrated with PCL (40:60 w/w) to regulate the structural flexibility. Micronized HAM was incorporated to PCL/SF (10:90 w/w) to provide a biocompatible milieu with functions being conferred to facilitate intraperitoneal repair. After the blend electrospinning, the PCL/SF/HAM mesh was characterized in vitro and implanted into the rat model with a full-thickness defect for a comprehensive evaluation in comparison to the PCL and PCL/SF meshes. The results demonstrated that electrospinning fabricated PCL stabilized the mechanical elongation toward approximating the native counterparts after integrating with SF. After integrating with HAM, which is coupled with diverse biomolecular compositions, the developed PCL/SF/HAM mesh provided a better microenvironment for cell proliferation and vasculogenic network over other meshes without HAM addition and possessed the functions capable of inhibiting transforming growth factor β1 (TGF-β1) expression and collagen secretion under inflammatory conditions. Moreover, the functional mesh developed less-intensive adhesion along with histologically weaker inflammatory response and foreign body reaction than the PCL and PCL/SF meshes after 90 days in vivo. During the remodeling process, the bioactive structure induced more pronounced neovascularization and remarkable incorporation of collagen and elastin fibers and contractile filaments for a mechanically sufficient and physiologically stiffness-matched healing. This tailor-made mesh expands the intraperitoneal applicability of conventional electrospun meshes for a compliant remodeling in the repair of abdominal wall defects.

Management of Persistent Corneal Epithelial Defects with Human Amniotic Membrane-derived Dry Matrix

Objective

To report the outcomes of using human amniotic membrane-derived dry matrix (AMDDM) in the management of persistent corneal epithelial defects (PEDs) of various etiologies.

Methods

A cohort study of 84 patients age range 7 to 92 years with 93 PEDs were treated with AMDDM (Omnigen^® using OmniLenz^® at two centers (Queen Victoria Hospital and Maidstone Hospital) in the UK. The main outcome measures were healing response of PED and time to heal after application of AMDDM.

Results

A total of 106 applications of AMDDM were recorded for 81 patients (52 males, 29 females) with a spectrum of different etiologies. Fifty-eight percent of the eyes showed complete healing, and 28% showed partial decrease of the size of PEDs with average treatment length recorded as 22.4±12.3 days. In patients with limbal stem cell deficiency (n=44; aniridia=12, chemical injury=9, Stevens–Johnson syndrome=10), 50% of PEDs showed complete healing and 27% showed partial healing. In patients with microbial keratitis (n=21) (bacterial: 13, fungal: 4, herpetic: 3, acanthamoeba: 1) 57% of PEDs showed complete healing and 33% were partially healed. In patients with keratoplasty (n=16), 56% of PEDs showed complete healing and 31% were partially healed. Vision remained stable in 59% and improved in 27% of the study the population.

Conclusion

AMDDM can be easily applied in the clinical setting and has demonstrated its efficiency as a new tool to treat persistent epithelial defects.

Treating Public Health Dilemma of Gingival Recession by the Dehydrated Amnion Allograft: A 5-Year Longitudinal Study

Aim: This study aimed to evaluate the efficacy of dehydrated amnion allograft with coronally positioned flap procedure in paired Miller's class I recession defects.

Methods: A total of 51 subjects were included in the study with bilateral Miller's class I gingival recession defects. In the test group, patients were treated with an amniotic membrane (AM) with a coronally positioned flap, while in the control group, patients were treated with coronally positioned flap alone. Clinical parameters such as recession depth, recession width (RW), probing depth (PD), relative attachment level (RAL), width of keratinized gingiva (WKG), and thickness of keratinized gingiva (TKG) were recorded at baseline and after 5 years of follow-up.

Result: The mean baseline recession was 2.95 ± 0.89 in the test group and 2.70 ± 0.85 in the control group, and both were statically non-significant. At the end of 6 months, all the parameters, when compared with the baseline, showed a significant improvement. Intergroup comparison showed the non-significant difference in all settings except the TKG.

Conclusion: AM proved to help improve the TKG. This increase in thickness helps in the long-term maintenance of the gingival margin in Miller's class I recession defect.

Regulation of ERK1/2 and SMAD2/3 Pathways by Using Multi-Layered Electrospun PCL-Amnion Nanofibrous Membranes for the Prevention of Post-Surgical Tendon Adhesion

Background

Adhesion after tendon injury is a common complication in clinical practice. The lack of effective prevention mechanisms seriously affects the functional rehabilitation of patients. This research aimed to optimise the amniotic membrane and explain the mechanism of tendon–amniotic membrane by imitating the tendon sheath to construct a multilayer electrospun polycaprolactone (PCL) nanofibre membrane.

Materials and Methods

Fresh amnions were subjected to freezing and vacuum drying. The two surfaces of freeze-dried amnions were coated with PCL nanofibres by electrospinning, thereby forming a multilayer composite membrane and constructing a growth factor-sustained release system conforming to the tendon-healing cycle. The new materials were characterised, and the biological effects on tenocytes and fibroblasts were evaluated. The tendon injury model of New Zealand rabbits was constructed to observe the effects on tendon adhesion and healing.

Results

After freezing and vacuum drying, fresh amnions were found to effectively remove most of the cell components but retained the active components TGF-β1, bFGF, VEGF, and PDGF, as well as the fibrous reticular structure of the basement membrane. After coating with PCL nanofibres, a composite membrane mimicking the structure of the tendon sheath was constructed, thereby strengthening the tensile strength of the amnion. By up-regulating the phosphorylation of ERK1/2 and SMAD2/3, the adhesion and proliferation of tenocytes and fibroblasts were promoted, and collagen synthesis was enhanced. In the rabbit tendon repair model, the composite membrane effectively isolated the exogenous adhesion tissue and promoted endogenous tendon healing.

Conclusion

The composite membrane mimicking the structure of tendon sheath effectively isolated the exogenous adhesion tissue and achieved good tendon slip. By slowly releasing the growth factors TGF-β1, bFGF, VEGF and PDGF, the ERK1/2 and SMAD2/3 pathways were regulated. Consequently, endogenous tendon healing was promoted. This strategy can alternatively address the clinical problem of tendon adhesion.

Effects of Cryopreserved Amniotic Membrane-Umbilical Cord Allograft on Total Ankle Arthroplasty Wound Healing

Relatively high rates of wound healing complications continue to be reported with a total ankle arthroplasty (TAA) anterior incision. The amniotic membrane-umbilical cord (AM-UC) allograft is a regenerative orthobiologic adjunct that modulates wound healing by down-regulating inflammation, enhancing local healing and antimicrobial factors, and reducing scar formation. The purpose of this study was to determine whether local application of a cryopreserved AM-UC allograft enhances soft tissue healing after TAA. A total of 104 patients with symptomatic ankle arthritis who failed conservative management underwent standard TAA. At skin closure, patients were allocated to either the treatment (local application of AM-UC) or control (no allograft) group. Demographic data, patient comorbidities, and radiographic findings were collected. The primary outcome was a major complication necessitating reoperation. Secondary outcomes were time to healing, minor complications (i.e., skin dehiscence, local wound care, use of antibiotics), and patient scar assessment. Local application of an AM-UC allograft significantly decreased the overall time to skin healing (28.5 days vs 40 days; p = .03). Two patients required a reoperation for soft tissue wound complications, with no difference (p = 1.00) between the groups. No statistically significant difference was detected in terms of skin dehiscence, local wound care, or antibiotic prescriptions in the 2 groups. Regenerative technology using local application of a cryopreserved AM-UC allograft may enhance TAA outcomes by decreasing the time to healing. Larger randomized controlled trials are needed to determine whether an AM-UC allograft enhances soft tissue wound healing and ultimately reduces the incidence of devastating soft tissue complications.

Application of amniotic membrane in reconstructive urology; the promising biomaterial worth further investigation

Introduction: In reconstructive urology, autologous tissues such as intestinal segments, skin, and oral mucosa are used. Due to their limitations, reconstructive urologists are waiting for a novel material, which would be suitable for urinary tract wall replacement. Human amniotic membrane (AM) is a naturally derived biomaterial with a capacity to support reepithelization and inhibit scar formation. AM has a potential to become a considerable asset for reconstructive urology, i.e., reconstruction of ureters, urinary bladder, and urethrae. Areas covered: This review aims to discuss the potential application of human AM in reconstructive urology. The environment for urinary tract healing is particularly unfavorable due to the presence of urine. Due to its fetal origin, the bioactivity of AM is orientated to induce intrinsic regeneration mechanisms and inhibit scarring. This review introduces the concept of applying human AM in reconstructive urology procedures to improve their outcomes and future tissue engineering based strategies. Expert opinion: Many fields of medicine that have accomplished translational research have proven the usefulness of AM in clinical practice. There is an urgent need for studies to be conducted on large animal models that might convincingly demonstrate the underestimated potential of AM to urologists around the world.

Decellularized human fetal intestine as a bioscaffold for regeneration of the rabbit bladder submucosa

PURPOSE

We aim to report a method to create a natural acellular scaffold from human fetal small intestine for augmentation cystoplasty in rabbits.

METHODS

Fetal intestines were decellularized by immersion in a hypotonic solution. The success of this protocol was evaluated by histological analysis, scanning electron microscopy and measurement of collagen and sulfated glycosaminoglycan of the acellular tissues. Eight mature rabbits were selected and acellular scaffolds were implanted on the exposed urothelium. Urodynamic studies and cystography were performed after six months. At 14, 120 and 180days animals were sacrificed and augmented bladders were resected.

RESULTS

Histological analysis revealed formation of muscular layer and blood vessels in implanted scaffolds similar to normal bladder. These findings demonstrate the effective seeding of scaffold by host bladder cells. The tissue architecture of recellularized scaffold was similar to the native bladder.

CONCLUSIONS

Fetal intestine acellular matrix could be an exceptional scaffold for bladder augmentation cystoplasty and may pave the road for future studies in order to be used for clinical application.

Neurolysis with Amniotic Membrane Nerve Wrapping for Treatment of Secondary Wartenberg Syndrome: A Preliminary Report

Background: Entrapment of the superficial sensory branch of the radial nerve (SRN) commonly results in debilitating pain of the dorsoradial wrist. Symptom relief following SRN neurolysis is often incomplete or temporary due to recurrent perineural scarring.

Methods: We performed a retrospective review with prospective follow-up of all patients with SRN neuropathy who were treated with neurolysis and nerve wrapping using an amnion-based allograft adhesion barrier over a one-year interval. Measured outcomes included pain rated by Visual Analog Scale (VAS) and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) functional outcome scores.

Results: Three females satisfied inclusion. At mean follow-up of 28.9 months, all three patients exhibited improved pain (mean VAS change −4.7 ± 0.6), function (mean QuickDASH change −40 ± 5), and subjective satisfaction. No adverse events or reactions to the implanted tissue occurred.

Conclusions: SRN entrapment neuropathy was safely and effectively treated with neurolysis and amnion nerve wrapping in this small series. Use of this technique for perineural scar prevention warrants additional study in larger groups of patients and in other upper extremity entrapment neuropathies.

In vitro assessment of a novel, hypothermically stored amniotic membrane for use in a chronic wound environment

Chronic wounds require extensive healing time and place patients at risk of infection and amputation. Recently, a fresh hypothermically stored amniotic membrane (HSAM) was developed and has subsequently shown promise in its ability to effectively heal chronic wounds. The purpose of this study is to investigate the mechanisms of action that contribute to wound-healing responses observed with HSAM. A proteomic analysis was conducted on HSAM, measuring 25 growth factors specific to wound healing within the grafts. The rate of release of these cytokines from HSAMs was also measured. To model the effect of these cytokines and their role in wound healing, proliferation and migration assays with human fibroblasts and keratinocytes were conducted, along with tube formation assays measuring angiogenesis using media conditioned from HSAM. Additionally, the cell-matrix interactions between fibroblasts and HSAM were investigated. Conditioned media from HSAM significantly increased both fibroblast and keratinocyte proliferation and migration and induced more robust tube formation in angiogenesis assays. Fibroblasts cultured on HSAMs were found to migrate into and deposit matrix molecules within the HSAM graft. These collective results suggest that HSAM positively affects various critical pathways in chronic wound healing, lending further support to promising qualitative results seen clinically and providing further validation for ongoing clinical trials.

Isolation, culture, characterization and cryopreservation of stem cells derived from amniotic mesenchymal layer and umbilical cord tissue of bovine fetuses

ABSTRACT: Stem cells are undifferentiated cells with a high proliferation potential. These cells can be characterized by their in vivo ability to self-renew and to differentiate into specialized cell lines. The most used stem cell types, in both human and veterinary fields, are the mesenchymal stem cells (MSC) derived from bone marrow and adipose tissue. Nowadays, there is a great interest in using stem cells derived from fetal tissues, such as amniotic membrane (AM) and umbilical cord tissue (UCT), which can be obtained non-invasively at delivery time. Due to the scarcity of studies in bovine species, the aim of this study was to isolate, characterize, differentiate and cryopreserve MSC derived from the mesenchymal layer of amniotic membrane (AM), for the first time, and umbilical cord tissue (UCT) of dairy cow neonates after assisted delivery (AD) and from fetus at initial third of pregnancy (IT) obtained in slaughterhouse. Cells were isolated by enzymatic digestion of the tissue fragments with 0.1% collagenase solution. Six samples of AM and UCT at delivery time and six samples of AM and UCT at first trimester of pregnancy were subjected to morphology evaluation, imunophenotype characterization, in vitro osteogenic, adipogenic and chondrogenic differentiation and viability analysis after cryopreservation. All samples showed adherence to plastic and fibroblast-like morphology. Immunocytochemistry revealed expression of CD 44, NANOG and OCT-4 and lack of expression of MHC II in MSC from all samples. Flow cytometry demonstrated that cells from all samples expressed CD 44, did not or low expressed CD 34 (AM: IT-0.3%a, AD-3.4%b; UCT: 0.4%, 1.4%) and MHC II (AM: IT-1.05%a, AD-9.7%b; UCT: IT-0.7%a, AD-5.7%b). They were also capable of trilineage mesenchymal differentiation and showed 80% viability after cryopreservation. According to the results, bovine AM and UCT-derived cells, either obtained at delivery time or from slaughterhouse, are a painless and non-invasive source of MSC and can be used for stem cell banking.

Bladder Reconstruction with Human Amniotic Membrane in a Xenograft Rat Model: A Preclinical Study

Background: Human amniotic membranes (HAMs) are assumed to have a number of unique characteristics including durability, hypoallergenic and anti-inflammatory properties. Materials and Methods: Multilayer HAMs from caesarian sections were applied to repair defined bladder defects in male Sprague-Dawley rats. The animals were sacrificed at 7, 21 and 42 days after implantation. Bladder volume capacity after grafting was measured. Histological analyses were performed to asses a number of parameters including HAM degradation, inflammatory reaction, graft rejection and smooth muscle ingrowth. Results: One rat died from sepsis in the treated group. No severe complications or signs of leakage were observed. Bladder capacity did not change over time. The initially increased inflammation in the HAM group diminished significantly over time (p<0.05). No signs of HAM degradation were observed and smooth muscle staining increased over time. Conclusions: HAMs appear to be durable and hypoallergenic grafts. The assumed suitability for the reconstruction of urinary tract justifies further research on detailed immunological process in larger grafts.

Effects of amniotic epithelial cell transplantation in endothelial injury

Purpose

Human amniotic epithelial cells (hAECs) are promising tools for endothelial repair in vascular regenerative medicine. We hypothesized that these epithelial cells are capable of repairing the damaged endothelial layer following balloon injury of the carotid artery in adult male rats.

Results

Two days after injury, the transplanted hAECs were observed at the luminal side of the arterial wall. Then, 4 weeks after the injury, significant intimal thickening was observed in both untreated and cell implanted vessels. Constriction was decreased in both implanted and control animals. Immunohistochemical analysis showed a few surviving cells in the intact arterial wall, but no cells were observed at the site of injury. Interestingly, acetylcholine-induced dilation was preserved in the intact side and the sham-transplanted injured arteries, but it was a trend toward decreased vasodilation in the hAECs’ transplanted vessels.

Conclusion

We conclude that hAECs were able to incorporate into the arterial wall without immunosuppression, but failed to improve vascular function, highlighting that morphological implantation does not necessarily result in functional benefits and underscoring the need to understand other mechanisms of endothelial regeneration.

Recurrent cubital tunnel syndrome treated with revision neurolysis and amniotic membrane nerve wrapping

BACKGROUND

Perineural scarring of the ulnar nerve is a predominant cause of symptom recurrence after surgical treatment for primary cubital tunnel syndrome (CuTS). We report our preliminary experience in revision ulnar nerve decompression and nerve wrapping with an amniotic membrane allograft adhesion barrier for treatment of recurrent CuTS.

METHODS

We performed a retrospective review with prospective follow-up of patients with recurrent CuTS who were treated with revision neurolysis with amniotic membrane nerve wrapping. Preoperative elbow motion, grip and pinch strengths, pain level on the visual analog scale level, and the 11-item version of the Disabilities of the Arm, Shoulder and Hand functional outcome score were compared with postoperative values using paired t testing. Symptom characteristics, physical examination findings, complications, and level of satisfaction were also obtained.

RESULTS

Eight patients (mean age, 47.5 years) who had undergone at least 2 prior ulnar nerve operations satisfied study inclusion. At mean postoperative follow-up of 30 months, significant improvements were noted across all patients in visual analog scale pain levels (-3.5 vs. preoperatively; P < .0001), 11-item version of the Disabilities of the Arm, Shoulder and Hand scores (-30 vs. preoperatively; P < .0001), and grip strength (+25 pounds vs. preoperatively; P < .0001). Pinch strength and elbow motion were also significantly improved for those patients with comparative preoperative data available. All patients expressed subjective satisfaction with their results. No adverse reactions or complications occurred in any patients.

CONCLUSIONS

Ulnar nerve wrapping with amniotic membrane allograft, when combined with revision neurolysis, was a safe and subjectively effective treatment for patients with debilitating recurrent CuTS.

Demineralized Freeze Dried Bone Allograft With Amniotic Membrane in the Treatment of Periodontal Intrabony Defects - 12 Month Randomized Controlled Clinical Trial

AIM

The goal of randomized controlled clinical study was to compare the clinical and radiological outcomes of the combination of Open flap debridement, Amniotic membrane and Demineralized Freeze Dried bone Allograft with Open flap debridement and Demineralized Freeze Dried bone Allograft alone in the management of periodontal intrabony defects.

METHOD

10 patients with bilaterally similar intrabony defects were selected. Each of the intrabony defects were randomly allocated for control and test groups. Control group (n= 10) received open flap debridement (OFD) and Demineralized Freeze Dried bone Allograft (DFDBA) while the test group (n=10) received OFD, DFDBA and Amniotic membrane. Pocket Probing Depth reduction (PPD), Clinical Attachment Level (CAL) gain and radiographic bone gain were assessed.

RESULTS

Both the groups demonstrated statistically significant PPD reduction, CAL gain and radiographic bone gain. The Intrabony defect (IBD) reduction of 1.78 ± 0.04 mm in radiovisiography (RVG) and 2.02 ± 0.83 mm in cone beam computed tomography (CBCT) with defect resolution of 58.28 % (RVG) and 58.24 % (CBCT) was noted in test group when compared to control group.

CONCLUSION

All the parameters measured showed similar improvement such as PPD reduction, CAL gain, IBD reduction and defect resolution with OFD + DFDBA + AM and OFD + DFDBA, no statistical significant difference was observed between the two groups .

Clinical comparison of coronally-advanced flap plus amniotic membrane or subepithelial connective tissue in the treatment of Miller's class I and II gingival recessions: A split-mouth study

Background. The aim of the present study was to compare coronally advanced flap (CAF) plus amniotic membrane (AM) to CAF with connective tissue graft (CTG) in the treatment of Miller’s class I and II gingival recessions.

Methods. Eleven healthy subjects with thirty Miller’s class І and ІІ gingival recessions ≥3 mm, were selevted for this research and randomly assigned to two groups in a split-mouth design. In the control group gingival recessions were treated with CAF and CTG; however, in the test group the lesions were treated with (AM) and CAF. The clinical parameters, including recession depth (RD), recession width (RW), keratinized tissue width (WKT), probing depth (PD) and clinical attachment level (CAL), were measured at baseline and 1, 3 and 6 months postoperatively. Statistical significance was set at P < 0.01.

Results. Position changes of RD, RW, CAL, and MGJ were significant between baseline and one month after surgery (P < 0.01) in both the test and control groups and these values remained unchanged at 3- and 6-month follow-ups. There were no statistically significant differences in PD and WKT between baseline and 1-, 3- and 6-months intervals postoperatively. The mean root coverage values after 6 months were 75.5% and 63.1% for two groups, respectively. The mean recession depth reductions were 2.63±0.63 mm and 2±1.4 mm in the test and control groups, respectively.

Conclusion. The results of this research showed that application of AM instead of connective tissue decreased surgical operation time and patient discomfort but the amount of root coverage was not significantly different between the two methods.

Amniotic Tissues for the Treatment of Chronic Plantar Fasciosis and Achilles Tendinosis

Introduction. Allogeneic amniotic tissue and fluid may be used to treat chronic plantar fasciosis and Achilles tendinosis. This innovative approach involves delivering a unique allograft of live human cells in a nonimmunogenic structural tissue matrix to treat chronic tendon injury. These tissues convey very positive regenerative attributes; procurement is performed with maternal consent during elective caesarian birth. Materials and Methods. In the present investigation all patients were unresponsive to multiple standard therapies for a minimum of 6 months and were treated with one implantation of PalinGen SportFLOW around the plantar fascia and/or around the Achilles paratenon. The patients were given a standard protocol for postimplant active rehabilitation. Results. The analogue pretreatment pain score (VAS) of 8. By the fourth week after treatment, all patients had significantly reduced self-reported pain. Twelve weeks following the procedure the average pain level had reduced to only 2. No adverse reactions were reported in any of the patients. Conclusion. All patients in this study experienced heel or Achilles pain, unresponsive to standard therapy protocols. After treatment all patients noted significant pain reduction, indicating that granulized amniotic membrane and amniotic fluid can be successfully used to treat both chronic plantar fasciosis and Achilles tendinosis.

Accelerated Restoration of Ocular Surface Health in Dry Eye Disease by Self-Retained Cryopreserved Amniotic Membrane

PURPOSE

To evaluate the clinical efficacy of self-retained cryopreserved amniotic membrane in treating dry eye disease.

METHODS

Retrospective review of 10 patients treated with self-retained cryopreserved amniotic membrane (PROKERA® Slim [PKS], Bio-Tissue, Miami, FL) for moderate-to-severe dry eye refractory to conventional maximal medical treatments. Patients' symptoms, use of medications, conjunctival inflammation, corneal staining, and visual acuity were compared before and after treatment.

RESULTS

PKS was placed in 15 eyes of the 10 patients for 4.9 ± 1.5 days. All patients experienced symptomatic relief for a period of 4.2 ± 4.7 months (P<.001). Such improvement was accompanied by reduction of OSDI scores (P<.001), use of topical medications (P<.001), conjunctival hyperemia (P<.001), corneal staining (P<.001), and improvement of the visual acuity (P=.06). Linear regression analysis estimated that the optimal duration of PKS placement was 5 days to achieve an average symptom-free duration of 4 months in patients with dry eye. Surprisingly, PKS placement also generated improvement in the contralateral eyes.

CONCLUSION

This pilot study suggests that self-retained cryopreserved amniotic membrane via PKS can be used to treat moderate dry eye diseases and warrants further prospective controlled studies.

Stem Cells: Potential Therapy for Neonatal Injury?

Stem cell transplantation (SCT) is an established first-line or adjunctive therapy for a variety of neonatal and adult diseases. New evidence in preclinical models as well as a few human studies show the potential utility of SCT in neuroprotection and in the modulation of inflammatory injury in at risk-neonates. This review briefly summarizes current understanding of human stem cell biology during ontogeny and present recent evidence supporting SCT as a viable approach for postinsult neonatal injury.

Long-term efficacy of glycerine-processed amniotic membrane transplantation in patients with corneal ulcer

PURPOSE

The aim of this study was to determine the long-term treatment efficacy of glycerine-preserved human amniotic membrane transplantation in patients suffering from corneal ulcers.

METHODS

This was a retrospective, non-controlled, monocentric analysis. Included were patients with corneal ulcers that were non-responsive to ointment or contact lenses and had been treated by amniotic membrane transplantation with either the overlay or sandwich procedure. Analysis parameters were visual acuity before and following treatment, recurrence rate and subjective comfort at the last follow-up.

RESULTS

Of the 371 amniotic membrane transplantations that were conducted, 135 surgical treatments in 108 patients (51.9% male, 48.1% female; mean age 63.7 years) met the inclusion criteria. In total, 99 overlay and 36 multilayer amniotic membrane transplantations were performed. The follow-up period was 47.5 ± 66.7 weeks (mean ± SD). The recurrence rate at the last follow-up was 47.8% with overlay membranes and 51.8% with the sandwich technique. There was no significant change in best-corrected visual acuity following treatment with overlays (p = 0.219) or sandwich procedure (p = 0.703). At the last follow-up, 72.1% (overlay) and 78.3% (sandwich) of the patients reported either no pain or increased comfort.

CONCLUSION

The recurrence rates and changes in visual acuity following overlay or sandwich amniotic membrane transplantation in patients suffering from corneal ulcer were lower than reported elsewhere in the literature. More than half of the patients profited from each of the amniotic membrane transplantation techniques with respect to recurrence and postoperative comfort.

Microenvironmental factors involved in human amnion mesenchymal stem cells fate decisions

Human amnion mesenchymal stem cells (HAMCs) show great differentiation and proliferation potential and also other remarkable features that could serve as an outstanding alternative source of stem cells in regenerative medicine. Recent reports have demonstrated various kinds of effective artificial niche that mimic the microenvironment of different types of stem cell to maintain and control their fate and function. The components of the stem cell microenvironment consist mainly of soluble and insoluble factors responsible for regulating stem cell differentiation and self-renewal. Extensive studies have been made on regulating HAMCs differentiation into specific phenotypes; however, the understanding of relevant factors in directing stem cell fate decisions in HAMCs remain underexplored. In this review, we have therefore identified soluble and insoluble factors, including mechanical stimuli and cues from the other supporting cells that are involved in directing HAMCs fate decisions. In order to strengthen the significance of understanding on the relevant factors involved in stem cell fate decisions, recent technologies developed to specifically mimic the microenvironments of specific cell lineages are also reviewed. Copyright © 2015 John Wiley & Sons, Ltd.

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 × 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.

Therapeutic effect of human amniotic membrane-derived cells on experimental arthritis and other inflammatory disorders

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune disease caused by loss of immunologic self tolerance and characterized by chronic joint inflammation. Cells isolated from human amniotic membrane (HAMCs) were recently found to display immunosuppressive properties. The aim of this study was to characterize the effect of HAMCs on antigen-specific T cell responses in RA patients and to evaluate their therapeutic potential in a preclinical experimental model of RA.

METHODS

We investigated the effects of HAMCs on collagen-reactive T cell proliferation and cytokine production, on the production of mediators of inflammation by synoviocytes, and on the generation of Treg cells in peripheral blood mononuclear cells and synovial membrane cells isolated from RA patients. Mice with collagen-induced arthritis (CIA) were treated with HAMCs after disease onset, and clinical scores and joint levels of mediators of inflammation were evaluated. We determined Th1/Th17-mediated autoreactive responses in the mice by measuring the proliferation and the cytokine profile of lymph node cells restimulated with collagen.

RESULTS

Treatment with HAMCs suppressed synovial inflammatory responses and antigen-specific Th1/Th17 activation in cells isolated from RA patients. Moreover, HAMCs stimulated the generation of human CD4+CD25+FoxP3+ Treg cells with a capacity to suppress collagen-specific T cell responses. Systemic infusion of HAMCs significantly reduced the incidence and severity of CIA by down-regulating the 2 deleterious components of disease: Th1-driven autoimmunity and inflammation. In mice with CIA, HAMC treatment decreased the production of various inflammatory cytokines and chemokines in the joints, impaired antigen-specific Th1/Th17 cell expansion in the lymph nodes, and generated peripheral antigen-specific Treg cells. HAMCs also protected the mice from experimental sepsis, inflammatory bowel disease, and autoimmune encephalomyelitis.

CONCLUSION

HAMCs have emerged as attractive candidates for a cell-based therapy for RA.

Amniotic membrane properties and current practice of amniotic membrane use in ophthalmology in Slovenia

Amniotic membrane (AM) is the innermost, multilayered part of the placenta. When harvested, processed and stored properly, its properties, stemming from AM biological composition, make it a useful tissue for ophthalmic surgery. AM was shown to have several beneficial effects: it promotes epithelization, has antimicrobial effects, decreases inflammation, fibrosis and neovascularization. Many case reports and case series as well as practical experience (e.g. reconstruction of conjunctival and corneal defects, treatment of corneal ulcers) demonstrated the beneficial effect of AM for different ophthalmological indications. The combination of the above mentioned beneficial effects and reasonable mechanical properties are also the reason why AM is used as a substrate for ex vivo expansion of epithelial progenitor cells. Recently, amnion-derived cells, which also have stem cell characteristics, have been proposed as potential contributors to cell-based treatment of ocular surface disease. However, the use of AM remains one of the least standardized methods in ophthalmic surgery. In this review, the various properties of AM and its current clinical use in ophthalmology in Slovenia are discussed.

Augmented dried versus cryopreserved amniotic membrane as an ocular surface dressing

Purpose

Dried amniotic membrane (AM) can be a useful therapeutic adjunct in ophthalmic surgery and possesses logistical advantages over cryopreserved AM. Differences in preservation techniques can significantly influence the biochemical composition and physical properties of AM, potentially affecting clinical efficacy. This study was established to investigate the biochemical and structural effects of drying AM in the absence and presence of saccharide lyoprotectants and its biocompatibility compared to cryopreserved material.

Methods

AM was cryopreserved or dried with and without pre-treatment with trehalose or raffinose and the antioxidant epigallocatechin (EGCG). Structural and visual comparisons were assessed using electron microscopy. Localisation, expression and release of AM biological factors were determined using immunoassays and immunofluorescence. The biocompatibility of the AM preparations co-cultured with corneal epithelial cell (CEC) or keratocyte monolayers were assessed using cell proliferation, cytotoxicity, apoptosis and migration assays.

Results

Drying devitalised AM epithelium, but less than cryopreservation and cellular damage was reduced in dried AM pre-treated with trehalose or raffinose. Dried AM alone, and with trehalose or raffinose showed greater factor retention efficiencies and bioavailability compared to cryopreserved AM and demonstrated a more sustained biochemical factor time release in vitro. Cellular health assays showed that dried AM with trehalose or raffinose are compatible and superior substrates compared to cryopreserved AM for primary CEC expansion, with increased proliferation and reduced LDH and caspase-3 levels. This concept was supported by improved wound healing in an immortalised human CEC line (hiCEC) co-cultured with dried and trehalose or raffinose membranes, compared to cryopreserved and fresh AM.

Conclusions

Our modified preservation process and our resultant optimised dried AM has enhanced structural properties and biochemical stability and is a superior substrate to conventional cryopreserved AM. In addition this product is stable and easily transportable allowing it to be globally wide reaching for use in clinical and military sectors.

Cardioprotection by placenta-derived stromal cells in a murine myocardial infarction model

BACKGROUND

Autologous cells for cell therapy of ischemic cardiomyopathy often display age- and disease-related functional impairment, whereas an allogenic immunotolerant cell product would allow off-the-shelf application of uncompromised donor cells. We investigated the cardiac regeneration potential of a novel, clinical-grade placenta-derived human stromal cell product (PLX-PAD).

METHODS

PLX-PAD cells derived from human donor placentas and expanded in a three-dimensional bioreactor system were tested for surface marker expression, proangiogenic, anti-inflammatory, and immunomodulatory properties in vitro. In BALB/C mice, the left anterior descending artery was ligated and PLX-PAD cells (n = 10) or vehicle (n = 10) were injected in the infarct border zone. Four weeks later, heart function was analyzed by two-dimensional and M-mode echocardiography. Scar size, microvessel density, extracellular matrix composition, myocyte apoptosis, and PLX-PAD cell retention were studied by histology.

RESULTS

In vitro, PLX-PAD cells displayed both proangiogenesis and anti-inflammatory properties, represented by the secretion of both vascular endothelial growth factor and angiopoietin-1 that was upregulated by hypoxia, as well as by the capacity to suppress T-cell proliferation and augment IL-10 secretion when co-cultured with peripheral blood mononuclear cells. Compared with control mice, PLX-PAD-treated hearts had better contractile function, smaller infarct size, greater regional left ventricular wall thickness, and less apoptosis after 4 wk. PLX-PAD stimulated both angiogenesis and arteriogenesis in the infarct border zone, and periostin expression was upregulated in PLX-PAD-treated hearts.

CONCLUSIONS

Clinical-grade PLX-PAD cells exert beneficial effects on ischemic myocardium that are associated with improved contractile function, and may be suitable for further evaluation aiming at clinical pilot trials of cardiac cell therapy.

A prospective study of 20 foot and ankle wounds treated with cryopreserved amniotic membrane and fluid allograft

We reviewed the background information and previous clinical studies that considered the use of allogeneic amniotic tissue and fluid (granulized amniotic membrane and amniotic fluid) in the treatment of chronic diabetic foot wounds. This innovation represents a relatively new approach to wound management by delivering a unique allograft of live human cells in a nonimmunogenic structural tissue matrix. Developed to fill soft tissue defects and bone voids and to convey antimicrobial and anti-inflammatory capabilities, granulized amniotic membrane and amniotic fluid does not require fetal death, because its procurement is performed with maternal consent during birth. In the present investigation, 20 chronic wounds (20 patients) that had been treated with standard wound therapy for a mean of 36.6 ± 31.58 weeks and with a mean baseline area of 10.15 ± 19.54 cm(2) were followed up during a 12-week observation period or until they healed. A total of 18 of the wounds (90%) healed during the 12-week observation period, and none of the wounds progressed to amputation. From our experience with the patients in the present case series, we believe that granulized amniotic membrane and amniotic fluid represents a useful option for the treatment of chronic diabetic foot wounds.

Mesenchymal stem cells from amnion and amniotic fluid in the bovine

Amnion and amniotic fluid (AF) are noncontroversial and inexhaustible sources of mesenchymal stem cells (MSCs) that can be harvested noninvasively at low cost. As in humans, also in veterinary field, presumptive stem cells derived from these tissues reveal as promising candidates for disease treatment, specifically for their plasticity, their reduced immunogenicity, and high anti-inflammatory potential. The aim of this work is to obtain and characterize, for the first time in bovine species, presumptive MSCs from the epithelial portion of the amnion (AECs) and from the AF (AF-MSCs) to be used for clinical applications. AECs display a polygonal morphology, whereas AF-MSCs exhibit a fibroblastic-like morphology only starting from the second passage, being heterogeneous during the primary culture. For both lines, the proliferative ability has been found constant over the ten passages studied and AECs show a statistically lower (P<0.05) doubling time with respect to AF-MSCs. AECs express MSC-specific markers (ITGB1(CD29),CD44,ALCAM(CD166),ENG(CD105), andNT5E(CD73)) from P1 to P3; in AF-MSCs, onlyITGB1,CD44, andALCAMmRNAs are detected;NT5Eis expressed from P2 andENGhas not been found at any passage. AF-MSCs and AECs are positive for the pluripotent markers (POU5F1(OCT4) andMYC(c-Myc)) and lack of the hematopoietic markers. When appropriately induced, both cell lines are capable of differentiating into ectodermal and mesodermal lineages. This study contributes to reinforce the emerging importance of these cells as ideal tools in veterinary medicine. A deeper evaluation of the immunological properties needs to be performed in order to better understand their role in cellular therapy.

Human amnion epithelial cells repair established lung injury

With a view to developing a cell therapy for chronic lung disease, human amnion epithelial cells (hAECs) have been shown to prevent acute lung injury. Whether they can repair established lung disease is unknown. We aimed to assess whether hAECs can repair existing lung damage induced in mice by bleomycin and whether the timing of cell administration influences reparative efficacy. In addition, we aimed to characterize the effect of hAECs on fibroblast proliferation and activation, investigating possible mechanisms of reparative action. hAECs were administered intraperitoneally (IP) either 7 or 14 days after bleomycin exposure. Lungs were assessed 7 days after hAEC administration. Bleomycin significantly reduced body weight and induced pulmonary inflammation and fibrosis at 14 and 21 days. Delivery of hAECs 7 days after bleomycin had no effect on lung injury, whereas delivery of hAECs 14 days after bleomycin normalized lung tissue density, collagen content, and α-SMA production, in association with a reduction in pulmonary leucocytes and lung expression of TGF-β, PDGF-α, and PDGF-β. In vitro, hAECs reduced proliferation and activation of primary mouse lung fibroblasts. Our findings suggest that the timing of hAEC administration in the course of lung disease may impact on the ability of hAECs to repair lung injury.

Healing of cervical necrotizing fasciitis using amniotic membrane as a dressing material

AIMS AND OBJECTIVES

Early recognition, aggressive surgical debridement, removal of cause, appropriate antibiotic therapy, improvement of immunocompromised state and dressing of the wound is the treatment of necrotizing cervical fasciitis. There are so many reported cases of burn and some reported cases of necrotizing fasciitis where amniotic membrane has been used as a dressing material, and that encouraged us to use it as a dressing material in our cases.

MATERIALS AND METHODS

Six cases of necrotizing cervical fasciitis reported to our department in a span of five years (2005 to 2010). Amniotic membrane taken from placenta of suitable donors had been used as a dressing material in these cases. Data collection included age, sex, medical history of the patients, size of the wound, pain felt by the patient, time taken for granulation tissue formation, total healing time, size of the scar and need for future reconstruction.

RESULTS

The sample consisted of six patients with a mean age of 45 years. Four of them were male. Etiology was always odontogenic. Five patients were immunocompromised. Three patients were chronic alcoholic. Average size of the wound was 42 square centimeter. Mean time taken for formation of granulation tissue was 22 days; mean total healing time was 36 days. In every case patient reported with pain, which gradually diminished after first application of amniotic membrane. In three cases, pain on fourth day after first application of amniotic membrane was nil (VAS scale). In rest three cases, pain on sixth day after first application of amniotic membrane was nil (VAS scale). Average size of the scar was 9 cm(2). Secondary scar revision was required in all six cases.

CONCLUSION

Our study concludes that amniotic membrane can be used effectively as a dressing material in necrotizing cervical fasciitis.

Concise review: Bone marrow for the treatment of spinal cord injury: mechanisms and clinical applications

Transplantation of bone marrow stem cells into spinal cord lesions enhances axonal regeneration and promotes functional recovery in animal studies. There are two types of adult bone marrow stem cell; hematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs). The mechanisms by which HSCs and MSCs might promote spinal cord repair following transplantation have been extensively investigated. The objective of this review is to discuss these mechanisms; we briefly consider the controversial topic of HSC and MSC transdifferentiation into central nervous system cells but focus on the neurotrophic, tissue sparing, and reparative action of MSC grafts in the context of the spinal cord injury (SCI) milieu. We then discuss some of the specific issues related to the translation of HSC and MSC therapies for patients with SCI and present a comprehensive critique of the current bone marrow cell clinical trials for the treatment of SCI to date.

Characterization and potential applications of progenitor-like cells isolated from horse amniotic membrane

The aim of this work was to isolate, for the first time, progenitor-like cells from the epithelial (AECs) and mesenchymal (AMCs) portions of the horse amniotic membrane, and to define the biological properties of these cells. AECs displayed polygonal epithelial morphology, while AMCs were fibroblast-like. Usually, six to eight passages were reached before proliferation decreased, with 13.08 and 26.5 cell population doublings attained after 31 days for AECs and AMCs, respectively. Immunocytochemical studies performed at passage 3 (P3) showed that both cell populations were positive for the expression of specific embryonic markers (TRA-1-60, SSEA-3, SSEA-4 and Oct-4). Meanwhile, RT-PCR performed at P1 and P5 showed expression of mesenchymal stem/stromal cell markers (CD29, CD105, CD44 and CD166) with negativity for CD34 at P1, although this marker began to be expressed by P5. The cells also expressed MHC-I at both P1 and P5, but lacked MHC-II expression at P1. Both AECs and AMCs demonstrated high plasticity, differentiating in vitro toward the osteogenic, adipogenic, chondrogenic and neurogenic lineages. Equine amnion-\derived cells could also be frozen and recovered without loss of their functional integrity in terms of morphology, presence of specific stemness markers and differentiation ability, although the renewal capacity was lower than that observed for freshly isolated cells. To investigate potential therapeutic effects and cell tolerance in vivo, horse amnion-derived cells were allogeneically injected into three horses with tendon injuries, resulting in a quick reduction in tendon size and ultrasonographic cross-sectional area measurements. These results suggest that horse amnion-derived cells may be useful for cell therapy applications.

Fetal adnexa derived stem cells from domestic animal: progress and perspectives

The fetal adnexa such as umbilical cord, amnion and amniotic fluid have been proposed as ideal sources of different stem cell lineages. Use of adnexal tissue has many potential advantages, including the noninvasive nature of the isolation procedure, the large tissue mass from which cells can be harvested with high efficiency and the potential of these cells to differentiate. Moreover, particularly in human medicine, the harvesting of these tissues is more ethically acceptable making these sources of stem cells very attractive for regenerative therapies and biotechnological applications. The adnexal tissue cells preserve some of the characteristics of the primitive embryonic layers from which they originate. Indeed, many studies indicate that these stem cells exhibit some features of embryonic stem cells as expression of embryonic markers and proliferation capability, without showing immunogenicity. However, the differentiation potential of these cells, either in vivo or in vitro, is intermediate between the pluripotent embryonic stem cells and the multipotent adult stem cells. Non-embryonic extra-fetal derived stem cells have opened new perspectives for developmental biology and for regenerative medicine, not only in humans but also in animals. In this update, we report the state of the art of fetal adnexa-derived stem cells from domestic animals and analyze their applications and potential uses in veterinary medicine.

Amniotic membrane is an immunosuppressor of peripheral blood mononuclear cells

Amniotic membrane (AM) is the inner layer of the placenta, which is in contact with the fetus; it has been used for transplantation in ocular surface diseases. It has been reported that amniotic membrane promotes epithelialization, inhibits angiogenesis and diminishes ocular inflammation. A persistent epithelial defect is the delay in epithelial wound healing caused by infiltrating inflammatory cells into the cornea and amniotic membrane transplantation has been successfully used in its treatment, however the mechanism of action in inhibiting inflammation it is not well understood. This study was aimed at determining whether denuded amniotic membrane (dAM) induces anti-inflammatory effects on peripheral blood mononuclear cells.

METHODS

Human peripheral blood mononuclear cells (PBMC) were cultured on dAM. Proliferation and apoptosis assays were performed on PBMC; and synthesis and secretion of pro-inflammatory cytokines by these cells was analyzed.

RESULTS

dAM induced apoptosis and inhibited cell proliferation of PBMC; and abolished the synthesis and the secretion of pro-inflammatory cytokines even when they were LPS stimulated. In contrast, when PBMC were cultured on hydrophilic membrane cell culture inserts, apoptosis was not significantly induced, cell proliferation was conserved, and synthesis and secretion of pro-inflammatory cytokines were not affected.

CONCLUSIONS

Taken together, these results could explain the anti-inflammatory in vivo effects observed when the amniotic membrane is used as a transplant.

Maternal obesity markedly increases placental fatty acid transporter expression and fetal blood triglycerides at midgestation in the ewe

Obesity of women at conception is increasing, a condition associated with offspring obesity. We hypothesized that maternal obesity increases placental fatty acid transporter (FATP) expression, enhancing delivery of fatty acids to their fetuses. Sheep are a commonly utilized biomedical model for pregnancy studies. Nonpregnant ewes were randomly assigned to a control group [100% of National Research Council (NRC) recommendations] or obese group (OB, 150% of NRC) from 60 days before conception to 75 or 135 days of gestation (dG; term = 150 dG), when placental cotyledonary tissue was collected for analysis. Fetuses of OB ewes were markedly heavier (P < 0.05) on 75 dG than fetuses from control ewes, but this difference disappeared by 135 dG. Maternal obesity markedly increased (P < 0.05) cholesterol and triglyceride concentrations of both maternal and fetal blood. There is no difference in lipoprotein lipase mRNA expression between control and OB group at either gestational age. On 75 dG, the mRNA expression of FATP1 (P < 0.05), FATP4 (P = 0.08), and fatty acid translocase CD (cluster of differentiation) 36 (P < 0.05) proteins were more enhanced in cotyledonary tissue from OB than control ewes; consistently, protein expression of FATP1 and FATP4 was increased (P < 0.05). Similarly, on 135 dG, the mRNA levels of FATP1, FATP4, and CD36 were all higher (P < 0.05), but only FATP4 protein content was enhanced (P < 0.05) in OB cotyledonary tissue. Peroxisome proliferator-activated receptor (PPAR)-γ regulates the expression of FATPs. Both the mRNA expression and protein content of PPARγ were increased in OB cotyledonary in the midgestation. In conclusion, maternal obesity enhances the mRNA expression and protein content of FATPs in cotyledonary in the midgestation, which is associated with higher PPARγ content in cotyledonary.

Cryopreserved amniotic membrane for modulation of periodontal soft tissue healing: a pilot study

BACKGROUND

The purpose of this randomized study is to evaluate cryopreserved amniotic membrane (CAM) for helping cicatrization and wound healing after dental implant surgery. Epithelialization, pain, infection, inflammation, and scarring were studied.

METHODS

CAM was placed in surgical wounds related to implant surgery. The extent of healing was evaluated by a masked investigator for lesion size, epithelialization, pain, infection, inflammation, and scarring. A clinical evaluation occurred at baseline, 72 and 144 hours, 2 weeks, and 1, 1.5, and 3 months. The results were compared to conventionally managed, similar lesions that were treated the same day in the same patient allowing each patient to serve as their own control.

RESULTS

This prospective randomized study showed statistically significant differences between experimental and control groups regarding cicatrization, wound healing, and pain. The effects of the membrane were statistically significant during the first 3 weeks of the study, and thereafter, the effects of the membrane for the two groups were equivalent.

CONCLUSIONS

CAM was effective in helping cicatrization and wound healing. CAM supported the growth of the epithelium and, thus, facilitated migration and reinforced adhesion. It also decreased the pain of subjects. Regarding dental implants, the use of CAM is not cost effective. New studies evaluating other oral conditions are encouraged.

Toward cell therapy using placenta-derived cells: disease mechanisms, cell biology, preclinical studies, and regulatory aspects at the round table

Among the many cell types that may prove useful to regenerative medicine, mounting evidence suggests that human term placenta-derived cells will join the list of significant contributors. In making new cell therapy-based strategies a clinical reality, it is fundamental that no a priori claims are made regarding which cell source is preferable for a particular therapeutic application. Rather, ongoing comparisons of the potentiality and characteristics of cells from different sources should be made to promote constant improvement in cell therapies, and such comparisons will likely show that individually tailored cells can address disease-specific clinical needs. The principle underlying such an approach is resistance to the notion that comprehensive characterization of any cell type has been achieved, neither in terms of phenotype nor risks-to-benefits ratio. Tailoring cell therapy approaches to specific conditions also requires an understanding of basic disease mechanisms and close collaboration between translational researchers and clinicians, to identify current needs and shortcomings in existing treatments. To this end, the international workshop entitled "Placenta-derived stem cells for treatment of inflammatory diseases: moving toward clinical application" was held in Brescia, Italy, in March 2009, and aimed to harness an understanding of basic inflammatory mechanisms inherent in human diseases with updated findings regarding biological and therapeutic properties of human placenta-derived cells, with particular emphasis on their potential for treating inflammatory diseases. Finally, steps required to allow their future clinical application according to regulatory aspects including good manufacturing practice (GMP) were also considered. In September 2009, the International Placenta Stem Cell Society (IPLASS) was founded to help strengthen the research network in this field.