WHITE PAPERS


Immunogenicity, Inflammation & Fibrosis

Amniotic membrane and amniotic cells: Potential therapeutic tools to combat tissue inflammation and fibrosis? (download)

Placenta. 2011 Oct;32 Suppl 4:S320-5. doi: 10.1016/j.placenta.2011.04.010. Epub 2011 May 12.

Manuelpillai U1, Moodley Y, Borlongan CV, Parolini O. 1Monash Institute of Medical Research, Monash University, Clayton, Victoria 3168, Australia.

Abstract In addition to the placenta, umbilical cord and amniotic fluid, the amniotic membrane is emerging as an immensely valuable and easily accessible source of stem and progenitor cells. This concise review will focus on the stem/progenitor cell properties of human amniotic epithelial and mesenchymal stromal cells and evaluate the effects exerted by these cells and the amniotic membrane on tissue inflammation and fibrosis.

Copyright © 2011 Elsevier Ltd. All rights reserved. PMID: 21570115 [PubMed – indexed for MEDLINE]

 

Immunogenicity of human amniotic membrane in experimental xenotransplantation (download)

Invest Ophthalmol Vis Sci. 2001 Jun;42(7):1539-46.

Kubo M1, Sonoda Y, Muramatsu R, Usui M.
1Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan.

Abstract

PURPOSE: The immunogenic characterization of amniotic membrane is still unknown. This study was designed to examine the immunogenicity of human amniotic membrane, by using experimental xenotransplantation models.

METHODS: Anti-human class I, class II, and Fas ligand monoclonal antibodies were used against cryopreserved amniotic membrane and cell viability tested for cryopreserved amniotic membrane. Amniotic membranes were then transplanted to the limbal area, intracorneal space, and under the kidney capsule. The scores of transparency and neovascularization after transplantation were recorded by slit lamp microscopy. Host cell infiltration was examined by hematoxylin-eosin or immunohistochemical staining. Control grafts were transplanted human cryopreserved skin grafts.

RESULTS: Strong class I expression was observed in amniotic epithelium, mesenchymal cells, and fibroblasts in cryopreserved amniotic membrane. Some fibroblast cells unexpectedly expressed class II antigen. Fas ligand-positive cells were also detected in mesenchymal cells of amniotic stroma. Approximately 50% of epithelial cells of amniotic membrane cryopreserved for several months were still viable. In limbal transplantation, although some CD4(+) and CD8(+) T cells surrounded the amniotic graft, the response was mild. In intracorneal transplantation, all grafted amniotic membranes were accepted and clear, without host cell infiltration. In contrast, all skin grafts were rejected within 3 weeks after intracorneal transplantation. In amniotic membrane transplantation under the kidney capsule, extremely few host vessels and cells infiltrated the amniotic membrane; however, more host cells infiltrated the skin tissues under the kidney capsule.

CONCLUSIONS: Amniotic membrane seems to be immune-privileged tissue and to contain some immunoregulatory factors, including HLA-G and Fas ligand. The amniotic membrane may be useful to supplement corneal collagen, and it may be applied not only to the ocular surface but also intracorneally.

PMID: 11381058 [PubMed – indexed for MEDLINE]

 

Review preclinical studies on placenta-derived cells and amniotic membrane: An update (download)

Placenta. 2011 Mar;32 Suppl 2:S186-95. doi: 10.1016/j.placenta.2010.12.016. Epub 2011 Jan 19.

Parolini O1, Caruso M.
1Centro di Ricerca E. Menni, Fondazione Poliambulanza-Istituto Ospedaliero, Brescia, Italy.

Abstract
Recent years have seen considerable advances in our knowledge of the biology and properties of stem/progenitor cells isolated from placental tissues. This has encouraged researchers to address the potential effects of these cells in animal models of different diseases, resulting in increasing expectations regarding their possible utility for cell-based therapeutic applications. This rapidly evolving research field is also enriched by studies aimed at expanding the use of the whole amniotic membrane (AM), a well-known surgical material, for pathological conditions other than those tested so far and for which clinical applications already exist. In this review, we provide an update on studies that have been performed with placenta-derived cells and fragments of the entire AM to validate their potential clinical applications in a variety of diseases, in particular those associated with degenerative processes induced by inflammatory and fibrotic mechanisms. We also offer, as far as possible, insight into the interpretation and suggested mechanisms to explain the most important outcomes achieved to date.

Copyright © 2011 Elsevier Ltd. All rights reserved.
PMID: 21251712 [PubMed – indexed for MEDLINE]

 

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

Clin Exp Allergy. 2005 Jul;35(7):941-8.

Solomon A1, Wajngarten M, Alviano F, Anteby I, Elchalal U, Pe’er J, Levi-Schaffer F.
1Department of Ophthalmology, Hadassah University Hospital, The Hebrew University–Hadassah Faculty of Medicine, Jerusalem, Israel.

Abstract

BACKGROUND: The amniotic membrane (AM), which is the innermost layer of the placenta, was shown to possess anti-inflammatory and anti-fibrotic properties in various in vitro and clinical studies.

PURPOSE: To evaluate the anti-fibrotic and anti-inflammatory effects of the AM matrix (AMM) on human conjunctival and lung fibroblasts in an in vitro system that tests fibrotic and inflammatory responses at the effector stages of allergic inflammation.

METHODS: Human conjunctival or lung fibroblasts were seeded on plastic or on the stromal aspect of the AM, which was mounted on plastic inserts. Sonicates of human peripheral blood eosinophils activated with lipopolysaccharide (LPS), or human mast cell (HMC-1) leukaemia cell sonicates, were added to sub-confluent fibroblast monolayers. Proliferation of the sub-confluent fibroblasts was assessed using the [3H]-thymidine incorporation assay. The production of transforming growth factor (TGF)-beta1, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-8 in conjunctival or lung fibroblasts was measured in conditioned media from these cultures by ELISA.

RESULTS: After 4 days in culture, the [3H]-thymidine incorporation assay indicated a reduced proliferation of activated conjunctival and lung fibroblasts when cultured directly on the AMM. The production of both TGF-beta1 and IL-8 was significantly suppressed in activated conjunctival fibroblasts cultured on the AMM compared with those cultured on plastic, while the production of both TGF-beta1 and GM-CSF was decreased in human lung fibroblast cultured on the AMM.

CONCLUSIONS: The AMM is capable of suppressing fibrotic responses in an in vitro system of effector stages of ocular allergic inflammation. These data may provide a basis for exploring matrix components in the AM for the treatment of allergic eye disease.

PMID: 16008682 [PubMed – indexed for MEDLINE]

 

Wounds

Amniotic membrane induces epithelialization in massive posttraumatic wounds (download)

Wound Repair Regen. 2010 Jul-Aug;18(4):368-77. doi: 10.1111/j.1524-475X.2010.00604.x.

Insausti CL1, Alcaraz A, García-Vizcaíno EM, Mrowiec A, López-Martínez MC, Blanquer M, Piñero A, Majado MJ, Moraleda JM, Castellanos G, Nicolás FJ.
1Unidad de Terapia Celular, Hospital Universitario Virgen de la Arrixaca, El Palmar, Murcia, Spain.

Abstract
Large-surface or deep wounds often become senescent in the inflammatory or proliferation stages and cannot progress to reepithelialization. This failure makes intervention necessary to provide the final sealing epithelial layer. The best current treatment is autologous skin graft, although there are other choices such as allogenic or autologous skin substitutes and synthetic dressings. Amniotic membrane (AM) is a tissue of interest as a biological dressing due to its biological properties and immunologic characteristics. It has low immunogenicity and beneficial reepithelialization effects, with antiinflammatory, antifibrotic, antimicrobial, and nontumorigenic properties. These properties are related to its capacity to synthesize and release cytokines and growth factors. We report the use of AM as a wound dressing in two patients with large and deep traumatic wounds. Negative pressure wound therapy followed by AM application was capable of restoring skin integrity avoiding the need for skin graft reconstruction. AM induced the formation of a well-structured epidermis. To understand this effect, we designed some assays on human keratinocyte-derived HaCaT cells. AM treatment of HaCaT induced ERK1/2 and SAP/JNK kinases phosphorylation and c-jun expression, a gene critical for keratinocytes migration; however, it did not affect cell cycle distribution. These data suggest that AM substantially modifies the behavior of keratinocytes in chronic wounds, thereby allowing effective reepithelialization.

PMID: 20636551 [PubMed – indexed for MEDLINE]

 

Amniotic membrane transplantation in the treatment of chronic lower limb ulcers (download)

Actas Dermosifiliogr. 2012 Sep;103(7):608-13. Epub 2012 May 10.

Alsina-Gibert M1, Pedregosa-Fauste S.
1Servicio de Dermatología, Hospital Clínic, Transplant Services Foundation, Universitat de Barcelona, Barcelona, Spain.

Abstract

INTRODUCTION: Approximately 1% of the general population have venous or arterial lower limb ulcers. These lesions can be treated with biological skin substitutes such as cadaver skin or tissue-engineered skin equivalents, but treatment fails in 25% of cases, resulting in pain and loss of patient autonomy, as well as increased morbidity and health care costs. In the treatment of corneal ulcers, amniotic membrane has been shown to have antimicrobial and bacteriostatic properties, and to protect the wound without eliciting an immune response. The same properties have been reported in the treatment of burns and postthrombotic ulcers.

OBJECTIVES: To assess the effectiveness of amniotic membrane transplantation in the treatment of refractory chronic leg ulcers.

PATIENTS AND METHODS: Amniotic membrane was grafted onto 4 refractory ulcers in 3 patients. The mean time required for partial and complete re-epithelialization was calculated by measuring the wound area at weeks 0, 4, 8, 12, and 16. Pain intensity was assessed at the same intervals using a visual analog scale.

RESULTS: Complete wound re-epithelialization was achieved for 1 ulcer by week 8; in the other 3 cases, there was a 50% reduction in size compared to baseline. At week 16, the mean reduction in wound size for the 4 ulcers was 81.93%. The corresponding reduction in pain intensity was 86.6%. No adverse effects were observed.

CONCLUSIONS: Amniotic membrane transplantation might be an effective alternative for the treatment of refractory chronic vascular ulcers on the lower limbs.

Copyright © 2011 Elsevier España, S.L. and AEDV. All rights reserved.
PMID: 22578292 [PubMed – indexed for MEDLINE]

 

Amniotic membrane grafting in patients with epidermolysis bullosa with chronic wounds (download)

J Am Acad Dermatol. 2010 Jun;62(6):1038-44. doi: 10.1016/j.jaad.2009.02.048.

Lo V1, Lara-Corrales I, Stuparich A, Pope E.
1Division of Pediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada.

Abstract

BACKGROUND: Severe forms of epidermolysis bullosa (EB) are characterized by chronic, nonhealing wounds.

OBJECTIVE: We sought to evaluate the usefulness of amniotic membranes in patients with EB.

METHODS: A retrospective chart review of patients with EB who were treated with amniotic membranes (two patients, 8 applications) was conducted. The primary outcome measure was number of days to complete healing, and the secondary outcome measures were a qualitative wound score, a visual analog scale score, and potential adverse effects.

RESULTS: The number of days to detect a significant clinical response, defined as greater than 50% improvement, was 40.3 +/- 21.2 days. The median qualitative wound score was 2 (range 0-5). The mean visual analog scale score at last follow-up was 31.4 +/- 26.8. No adverse events were noted.

LIMITATIONS: Retrospective design, healing assessed by comparing photographs, and partial grafting of some wounds were limitations.

CONCLUSION: This proof-of-concept study revealed the potential usefulness of amniotic membrane grafting in promoting healing of chronic wounds in patients with EB.

Copyright 2009 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.
PMID: 20466177 [PubMed – indexed for MEDLINE]

 

Use of amniotic membrane transplantation in treatment of venous leg ulcers (download)

Wound Repair Regen. 2007 Jul-Aug;15(4):459-64.

Mermet I1, Pottier N, Sainthillier JM, Malugani C, Cairey-Remonnay S, Maddens S, Riethmuller D, Tiberghien P, Humbert P, Aubin F.
1Université de Franche Comté, Department of Dermatology, University Hospital and Medical School, Besançon, France.

Abstract
Amniotic membrane (AM), the most internal placental membrane, has unique properties including antiadhesive effects, bacteriostatic, wound protection and pain-reduction properties, as well as epithelialization initialization capacities. Furthermore, AM is widely available and less costly than other bioengineered skin substitutes. In a prospective pilot study, we evaluated the safety, feasibility, and the effects on healing of AM graft in 15 patients with chronic venous leg ulcers. AM grafts were prepared from placentas harvested during cesarean section. All grafted AM had adhered to the wound bed 7 days after being applied with a 100% engraftment rate. The percentage of granulation tissue increased significantly (from 17% on day 0 to 69% on day 14, p<0.0001), along with a significant decrease of fibrinous slough (from 36% at day 0 to 16% at day 14, p<0.001). A significant clinical response occurred in 12 patients (80%) including complete healing (20%) in three during the 3-month follow-up period. The ulcer surface area decreased significantly from a mean value (+/- standard deviation) of 4.59 +/- 2.49 cm(2) at baseline to 2.91+/-2.01 cm(2) on day 30 (p<0.001). All patients experienced a significant reduction of ulcer-related pain rapidly after AM transplantation. No adverse events were recorded. AM transplantation seems to function as a safe substrate, promoting proper epithelialization while suppressing excessive fibrosis. Further advantages of biotherapy with AM are its easy and low-cost production, and that it can be applied as an ambulatory treatment without immobilization. AM transplantation may thus be considered to be an alternative method for treating chronic leg ulcers.

PMID: 17650088 [PubMed – indexed for MEDLINE]

 

Burns

The role of allogenic amniotic membrane in burn treatment (download)

J Burn Care Res. 2008 Nov-Dec;29(6):907-16. doi: 10.1097/BCR.0b013e31818b9e40.

Kesting MR1, Wolff KD, Hohlweg-Majert B, Steinstraesser L.
1Department of Oral and Maxillofacial Surgery, Klinikum Rechts der Isar, Technische Universität München, München, Germany.

Abstract
Amniotic membrane (AM) has been used in burns for nearly 100 years. The purpose of this article is to give a comprehensive review of the English literature published in the last two decades (1987–2007) to present the current state of this therapy form. Three medical databases (PubMed, Medline, The Cochrane Library) and specific burn journals were electronically screened for relevant articles using carefully selected retrieval strategies and keywords (AM, amnion grafts, burns, wound dressing, amnion banking). Bibliographies of relevant articles were analyzed for additional pertinent publications. After exclusion of articles which referred to the use of AM in reconstructive and ophthalmologic surgery, the inquiry yielded 31 relevant articles in English language dealing with AM and burns. There was no publication fulfilling the criteria of evidence level I, 6 articles had evidence level II, 10 had evidence level III, 6 had evidence level IV, and 9 were merely narrative (level V). The review testifies to–in view of good tissue practice–heightened use of processed AM in burns, especially in the last decade. Randomized clinical trials favored the use of amnion in burns in the first place for promotion of wound healing and in the second place for its comfortable and less dressing changes. Antimicrobial effects, pain relief, reduction of fluid, and scar formation were demonstrated additionally.

PMID: 18849850 [PubMed – indexed for MEDLINE]

 

Amnion in the treatment of pediatric partial-thickness facial burns (download)

Burns. 2008 May;34(3):393-9. Epub 2007 Oct 24.

Branski LK1, Herndon DN, Celis MM, Norbury WB, Masters OE, Jeschke MG.
1Shriners Hospital for Children and University of Texas Medical Branch, 815 Market Street, Galveston, TX 77550, USA.

Abstract

BACKGROUND: Wound coverage for second-degree burns remains a clinical challenge. Human amniotic membranes have been used for many years in the treatment of burns; however, no large prospective clinical trials have been published. In this article, we present a novel and standardized procurement and processing method for amnion and investigate, whether the use of this biological dressing is safe and may represent a new therapeutic option for children with partial-thickness facial burns compared to standard topical treatment.

METHODS: Patients with partial-thickness burns of the face, neck and head admitted between 2003 and 2005 were included in this study. They were divided into two groups to receive either amnion (n=53) or topical antimicrobials (n=49). Demographics (age, gender, ethnicity, TBSA, burn areas), length of hospital stay (LOS), rate of infections (RI), time to total healing, and frequency of dressing changes were compared between the two groups. The long-term outcome was assessed in nine patients in the amnion group and eight patients in the topical group, who returned for up to 12-month follow-up visits.

RESULTS: Patients in the amnion group had significantly less dressing changes then in the control group (p<0.05). Time to healing, length of stay and the development of hypertrophic scarring was not different between the groups. Use of amnion was not associated with an increased risk of local infection.

CONCLUSION: This study indicates that amnion is safe and has advantages as wound coverage for second-degree facial burns compared to the standard topical ointments. Further studies with the use of amniotic membranes on the trunk and the extremities, as well as for coverage of grafted third-degree burns, have yet to be performed.

PMID: 17920202 [PubMed – indexed for MEDLINE]

 

Use of amniotic membrane, amniotic fluid, and placental dressing in advanced burn patients (download)

Chapter, Regenerative Medicine Using Pregnancy-Specific Biological Substances, pp 383-394, Date: 29 November 2010

N. Bhattacharya
Department of General Surgery, Obstetrics and Gynaecology and Clinical Immunology, Advanced Medical Research Institute, Gol Park, B.P. Poddar Hospital and Vidyasagore Hospital, Kolkata 700034, India

Abstract

INTRODUCTION: The development of wound infections is the most common cause of mortality and morbidity among burn patients. A variety of dressings have been used to cover and reduce burn wound sepsis and promote wound healing. The aim of the present study was to examine the effectiveness of composite and judicious use of different stem cell-rich pregnancy-specific biological substances (PSBS) such as freshly collected amniotic membrane, amniotic fluid, and the placenta in case of extensive burn wound.

MATERIALS and METHODS: Patients with more than 20% wound were admitted, and options were given for conservative management with PSBS dressing at a nonteaching hospital or provided with referral facility at the burns unit of another tertiary-level government hospital. Those who opted for treatment with PSBS (procured from hepatitis-, syphilis- and HIV-seronegative mothers having undergone cesarean deliveries) were treated initially at Bejoygarh State Hospital (1999–2006) and the same regimen was followed later at Vidyasagore Hospital (2006–2009). The area affected included both partial to complete thickness thermal burns. Patients suffering from chemical burns, or burned areas in sensitive parts of the body such as the genitals or face, were also included in this study from 1999 to 2009.
Result and analysis: Initially, 97 patients were randomly recruited for the present study of the utility of PSBS in the burn management. Of these, 33 patients, who did not agree to the PSBS protocol, were transferred to the burn unit of a tertiary-care hospital and were treated with broad spectrum antibiotics, application of silver sulfadiazine cream with electrolytes, and other supportive drugs to combat initial shock and infection till the patient was fit for autologous skin graft.
The rest, i.e., 64 burn patients (male 24, age 2–96 years, mean 36 ± 5.4 years and female 40, age 7–68 years, mean 32 ± 5.7 years) with 26–76% of total body surface area calculated on the basis of the famous rule of nine were enrolled in the present study for PSBS treatment (1999–2009).
Patients were treated with placenta (Step 1). After washing the burn site initially with normal saline, it was followed by gentle rubbing of the burned area with a freshly collected placenta’s maternal attachment site as a dressing material. This move may have a positive cytokine impact on the process of healing. Then, the burn site was washed with freshly collected amniotic fluid as a cell therapy source (because of its rich content of epithelial and mesenchymal stem cell component, leaving aside its antibacterial propensity as a helpful adjuvant) (Step 2). At last amniotic membrane is applied at the affected area (Step 3), as a temporary biological wound cover to expedite the healing and also to reduce the exudation, pain, and infection at the burn wound site with judicious application mode, i.e., chorionic side to augment vasculogenesis in early wound and the amniotic side to promote epithelialization lately. This is an effective step to augment the cell therapy component of the amniotic fluid.

CONCLUSION: The globally used skin substitutes currently available are costly and many are not universally available. The easily available and simple utilization of the biological waste generated from obstetric wards for the burn victims is very effective and rewarding. Use of stem cell-rich PSBS regimen has a profound regenerative impact in case of burn irrespective of the degree of burn. Its wider application is recommended on the basis of our experience of the present study, which has been carried out for 10 years (1999–2009).

DOI: 10.1007/978-1-84882-718-9_37, © Springer-Verlag London Limited 2011

 

Oral & Maxillofacial

Repair of oronasal fistulas with human amniotic membrane in minipigs (download)

Br J Oral Maxillofac Surg. 2010 Mar;48(2):131-5. doi: 10.1016/j.bjoms.2009.04.025. Epub 2009 May 23.

Kesting MR1, Loeffelbein DJ, Classen M, Slotta-Huspenina J, Hasler RJ, Jacobsen F, Kreutzer K, Al-Benna S, Wolff KD, Steinstraesser L.
1Department of Oral and Maxillofacial Surgery, Technische Universität München, Ismaninger Str. 22, D-81675 München, Germany.

Abstract
We evaluated the use of multilayer human amniotic membrane (HAM) as a grafting material for the repair of mid-palate oronasal fistulas in seven Berlin minipigs. After two weeks, three animals had the fistulas repaired with multilayered HAM grafts, three had them repaired with a collagen-based dermal substitute (INTEGRA((R)), Integra Life Sciences, Plainsboro, NJ, USA), and one fistula was left untreated to serve as a control. Grafts were interposed between the oral and nasal mucosa, traversing the fistulas. After healing for 40 days, the pigs were killed for clinical, histological, and immunohistochemical examination. Two of the three fistulas closed with HAM were successful, the diameter of the third was reduced in size, and there was no change in the diameter of the fistula in the control. This study shows successful closure of oronasal fistulas in minipigs using interposed grafts of cryopreserved HAM, and offers promise as a simple and effective technique for tension-free closure of such fistulas.

PMID: 19477056 [PubMed – indexed for MEDLINE]

 

Use of amnion as a graft material in vestibuloplasty: a clinical study (download)

Br J Oral Maxillofac Surg. 2012 Sep;50(6):545-9. doi: 10.1016/j.bjoms.2011.09.022. Epub 2011 Oct 24.

Kothari CR1, Goudar G, Hallur N, Sikkerimath B, Gudi S, Kothari MC.
1M.D.S Oral and Maxillofacial Surgery, Al-Badar Dental College and Hospital, Gulbarga, Karnataka, India.

Abstract
The need to cover the exposed periostium has meant that a number of materials including mucosal and skin grafts are regarded as suitable for grafting in oral and maxillofacial surgery. To circumvent the disadvantages of other materials such as skin, biological membranes have been suggested as options, including fetal membrane. The objective of the present study was to evaluate the clinical efficacy of amnion as a graft material for vestibuloplasty, to increase the depth of the sulcus for complete rehabilitation with dentures in 10 patients with a follow up period of 3 months. Ten patients with deficient depth of the mandibular vestibular sulcus who were referred from the Department of Prosthodontics were listed for mandibular labial vestibuloplasty using Clark’s technique followed by grafting with amnion over the denuded periostium. The vestibular depth was evaluated at the end of the 1st week, 2nd week, 4th week, and 3rd month postoperatively, and compared with the preoperative vestibular depth. We had no cases of graft necrosis either complete or partial. However, the reduction in the depth of the labial vestibule ranged from 17% to 50% after 3 months’ follow up. A mean (SD) labial vestibular depth of 13.3 (1.8)mm was achieved immediately postoperatively, and 10.0 (3.1)mm at 3 months’ follow up. We conclude that grafts of amniotic membrane are viable and reliable for covering of the raw surface, prevent secondary contraction after vestibuloplasty, and maintain the postoperative vestibular depth.

Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
PMID: 22024106 [PubMed – indexed for MEDLINE]

 

Histological evaluation of rabbit gingival wound healing transplanted with human amniotic membrane (download)

Int J Oral Maxillofac Surg. 2006 Mar;35(3):247-51. Epub 2006 Jan 18.

Rinastiti M1, Harijadi, Santoso AL, Sosroseno W.
1Department of Conservative Dentistry, Faculty of Dentistry, Gadjah Mada University, Yogyakarta 55281, Indonesia.

Abstract
Human amniotic membrane has been used as a material to accelerate wound healing and reconstruct damaged organs. The aim of the present study was to assess histologically human amniotic membrane transplantation on rabbit’s gingival wound. Three- to 4-month-old male rabbits were divided into 2 groups, i.e., control (group I) and amniotic membrane-transplanted animals (group II). Buccal gingival wounds were created by a punch-biopsy instrument and covered by a 5-layered human amniotic membrane for group II or left uncovered for group I. Gingival biopsies were taken at days 1, 3, 5, 7 and 10, processed for paraffin sections and stained with haematoxylin-eosin or von Gieson. Thickness of epithelial layer, the number of polymorphonuclear cells (PMN), fibroblasts and new blood vessels as well as density of collagen fibres were assessed. The results showed that the number of fibroblasts and new blood vessels, but not PMN, from group II was higher than that from group I (P < 0.05). Similarly, the epithelial thickness and density of collagen fibres from group II were significantly higher than those from group I (P < 0.05). The results of the present study indicate that amniotic membrane transplantation may induce rapid epithelialization and both granulation tissue and collagen formation but suppress inflammation, suggesting that amniotic membrane transplantation may promote rapid gingival wound healing in rabbits compared to secondary healing.

PMID: 16386878 [PubMed – indexed for MEDLINE]

 

Spine

Implantation of amniotic membrane to reduce postlaminectomy epidural adhesions (download)

Eur Spine J. 2009 Aug;18(8):1202-12. doi: 10.1007/s00586-009-1013-x. Epub 2009 Apr 30.

Tao H1, Fan H.
1Department of Orthopaedics and Traumatology, Xi-jing Hospital, The Fourth Military Medical University, 710032, Xi’an, China.

Abstract
Postlaminectomy epidural adhesion is implicated as a main cause of “failed back surgery syndrome” and associated with increased risk of complications during revision surgery. Various materials acting as mechanical barriers to reduce fibroblasts infiltration into epidural space have met with limited success. In present research, amniotic membrane (AM) was studied to investigate its effects on reducing epidural scar adhesion after laminectomy in a canine model. Laminectomy sites were created at L-1, L-3, L-5, and L-7 levels in 24 adult mongrel dogs. Freeze dried AM (FAM), cross-linked AM (CAM), and autologous free fat (AFF) were implanted, respectively, at a randomly assigned site in each dog with the remaining untreated site serving as internal control. The animals were sacrificed at 1, 6, and 12 weeks postoperatively. Then, gross pathologic observation including scar amount and adhesion tenacity, qualitative histology evaluation, and quantitative histology analysis were compared. Gross observation demonstrated that scar amount and adhesion tenacity of CAM group were significantly lower in comparison with those of FAM and non-treatment groups. A white, slightly vascularized CAM layer covered the dura mater without tenacious scar adhesion. The histology analysis also indicated reduced fibroblasts infiltration and consequent epidural fibrosis, which were similar to the results of AFF group. In conclusion, the CAM is effective in reducing epidural fibrosis and scar adhesion after laminectomy in canine model. It is a promising biomaterial for future clinical applications.

PMID: 19404691 [PubMed – indexed for MEDLINE] PMCID: PMC2899499

 

Effect of amniotic membrane to reduce postlaminectomy epidural adhesion on a rat model (download)

J Korean Neurosurg Soc. 2011 Jun;49(6):323-8. doi: 10.3340/jkns.2011.49.6.323. Epub 2011 Jun 30.

Choi HJ1, Kim KB, Kwon YM.
1Department of Neurosurgery, College of Medicine, Dong-A University, Busan, Korea.

Abstract

OBJECTIVE: Epidural fibrosis and adhesion are the main reasons for post-laminectomy sustained pain and functional disability. In this study, the authors investigate the effect of irradiated freeze-dried human amniotic membrane on reducing epidural adhesion after laminectomy on a rat model.

METHODS: A total of 20 rats were divided into two groups. The group A did not receive human amniotic membrane implantation after laminectomy and group B underwent human amniotic membrane implantation after laminectomy. Gross and microscopic findings were evaluated and compared at postoperative 1, 3 and 8 weeks.

RESULTS: The amount of scar tissue and tenacity were reduced grossly in group of rats with human amniotic membrane implantation (group B). On a microscopic evaluation, there were less inflammatory cell infiltration and fibroblast proliferation in group B.

CONCLUSION: This experimental study shows that implantation of irradiated freeze-dried human amniotic membrane reduce epidural fibrosis and adhesion after spinal laminectomy in a rat model.

PMID: 21887388 [PubMed] PMCID: PMC3158473

 

General Surgery

The Effects of Human Amniotic Membrane on Healing of Colonic Anastomosis in Dogs (download)

Annals of Colorectal Research. 2013 December; 1(3): 97-100. , DOI: 10.17795/acr-16139

Neda Najibpour1; Mohammad Bagher Jahantab2 ; Massood Hosseinzadeh3; Reza Roshanravan3 ; Sam Moslemi2; Salar Rahimikazerooni3; Ali Reza Safarpour4; Leila Ghahramani3; and Seyed Vahid Hosseini3,
1Department of Surgery, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran, 2Department of Surgery, Shiraz University of Medical Sciences, Shiraz, IR Iran, 3Colorectal Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran, 4Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran

Abstract

BACKGROUND: Anastomotic leakage is claimed to be responsible for about one third of deaths following colon surgeries. Therefore, research on applied materials that may prevent leakage and improve healing requires more attention.

OBJECTIVES: This study was conducted to determine surgical and histological outcomes of applying human amniotic membrane (HAM) in colonic anastomosis in dogs.

MATERIALS AND METHODS: Eight cross-breed male dogs were divided into two equal groups. After anesthesia and exploration, 5cm of left colon was resected, and end-to-end anastomosis was performed in a single layer. In the treatment group (B), HAM patch measuring 2×3 cm was wrapped around the anastomotic line. Mann-Whitney U test was used to compare the results in the two groups due to small sample size, and normal distribution of data was examined using the kolmogorov-simirnov test (P = 0.03).

RESULTS: Modified scoring system for surgical wound healing was used to identify the grade of healing in all samples. The healing score was significantly higher in the HAM group (P = 0.01).

CONCLUSION: HAM plays a positive role in healing of colonic anastomosis, and would lead to better histological outcomes compared to simple anastomosis in dogs.

 

Dried human amniotic membrane as an antiadherent layer for intraperitoneal placing of polypropylene mesh in rats (download)

Surg Endosc. 2013 Apr;27(4):1435-40. doi: 10.1007/s00464-012-2604-x. Epub 2013 Feb 8.

Di Loreto FP1, Mangione A, Palmisano E, Cerda JI, Dominguez MJ, Ponce G, Bernaus M, Gaffuri S, Torresi G, Bianco S.
1General Surgery Department, School Hospital Eva Perón, Granadero Baigorria, Argentina.

Abstract

BACKGROUND: Intraabdominal peritoneal onlay polypropylene (PP) mesh repair of incisional hernia has the potential risk of adhesions, bowel obstructions, and intestinal fistulae. Fresh or cryopreserved human amniotic membrane (HAM) has been tested as an antiadherent layer in animals, with excellent outcomes. However, it has disadvantages: it is difficult to handle, and it is expensive to store. Another processing method is available: drying in a laminar flow hood and gamma irradiation. Because this method impairs the membrane’s cell viability, it may affect its antiadherent properties. However, such properties may also result from the collagen matrix and its basement membrane, which remain after drying. The aim of the present study was to asses dried irradiated HAM in adhesion prophylaxis in rats.

METHODS: Twenty-four female rats were randomized into two groups. In the first group (control group), PP meshes were placed in the intraabdominal space, and in the second group (treatment group), PP meshes coated with HAM were used. Animals were killed on day 30 after surgery. Adhesions and parietal prosthetic incorporation were assessed macroscopically and expressed as the average percentage of the covered area. The portion of the abdominal wall was then resected for histological testing.

RESULTS: The treatment group had a significantly higher percentage of adhesions and parietal incorporation compared with the control group (p = 0.003). Histological testing showed a higher inflammatory response in the treatment group, with an intense foreign body reaction.

CONCLUSIONS: Dried irradiated HAM does not prevent adhesion formation in intraabdominal peritoneal onlay PP mesh repair in rats. Any use of this biomaterial in adhesion prophylaxis must be undertaken respecting graft cell viability as much as possible.

PMID: 23392973 [PubMed – indexed for MEDLINE]

 

Gynecology

Functional and anatomic results of amnion vaginoplasty in young women with Mayer-Rokitansky-Küster-Hauser syndrome (download)

Fertil Steril. 2010 Jun;94(1):317-23. doi: 10.1016/j.fertnstert.2009.01.154. Epub 2009 Mar 27.

Fotopoulou C1, Sehouli J, Gehrmann N, Schoenborn I, Lichtenegger W.
1Department of Gynecology and Obstetrics, Charité, Campus Virchow Clinic, University Hospital, Berlin, Germany.

Abstract

OBJECTIVE: To evaluate the surgical outcome and the long-term anatomic and functional results in young women with Mayer-Rokitansky-Küster-Hauser Syndrome (MRKH) undergoing neovaginal creation with amniotic membranes.

DESIGN: Evaluation of surgical and functional outcome according to clinical records and validated questionnaires about sexuality (Female Sexual Function Index [FSFI]) over a 1.5-year follow-up period.

SETTING: University hospital and referral center for pediatric and adolescent gynecology.

PATIENT(S): Seven patients with congenital vaginal aplasia with a mean age of 20.86 +/- 3.56 years (range 17-26 years).

INTERVENTION(S): McIndoe procedure modified by the application of human freeze-dried amniotic membranes.

MAIN OUTCOME MEASURE(S): Anatomic success was defined by a vaginal length >or=8 cm, and a width allowing the easy introduction of two fingers. FSFI scores were applied to define functional results.

RESULT(S): Mean neovaginal length was 9.3 cm (range 4-12 cm). The mean FSFI score was 30.0 +/- 6.9. Major operative complications occurred in one patient. In six out of seven patients satisfactory anatomic and functional results were achieved.

CONCLUSION(S): The surgical dissection of the vesicorectal space and the application of human amnion over a vaginal mold to create a neovagina results in satisfying anatomic and functional outcome with low perioperative morbidity in MRKH patients.

Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
PMID: 19328473 [PubMed – indexed for MEDLINE]

 

Human amnion as a temporary biologic barrier after hysteroscopic lysis of severe intrauterine adhesions pilot study (download)

J Minim Invasive Gynecol. 2010 Sep-Oct;17(5):605-11. doi: 10.1016/j.jmig.2010.03.019. Epub 2010 Jun 23.

Amer MI1, Abd-El-Maeboud KH, Abdelfatah I, Salama FA, Abdallah AS.
1Department of Obstetrics and Gynecology, Ain Shams University, Helliopolis, Cairo, Egypt.

Abstract

STUDY OBJECTIVE: To estimate the efficacy of fresh and dried amnion graft after hysteroscopic lysis of severe intrauterine adhesions in decreasing its recurrence and encouraging endometrial regeneration.

DESIGN: Pilot prospective randomized comparative study (Canadian Task Force classification I).

SETTING: Ain Shams Medical School, Cairo, Egypt.

PATIENTS: Forty-five patients with severe intrauterine adhesions. Primary symptom was infertility with or without menstrual disorders such as amenorrhea or hypomenorrhea.

INTERVENTIONS: Patients were randomized preoperatively using a computer-generated randomization sheet into 3 groups of 15 patients each. Allocation to any group was concealed in an opaque envelope, which was opened at the time of operation. Hysteroscopic lysis of intrauterine adhesions was followed by insertion of an intrauterine balloon only (group 1) or either fresh amnion graft (group 2) or dried amnion graft (group 3) for 2 weeks. Diagnostic hysteroscopy was performed at 2 to 4 months postoperatively.

MEASUREMENTS AND MAIN RESULTS: Adhesion grade, menstruation, uterine length, complications, and reproductive outcome were determined. There was significant improvement in adhesion grade with amnion graft vs intrauterine balloon alone (p = .003). Improvement was greater with fresh amnion than with dried amnion (p = .01). Normal menstruation occurred in 4 patients (28.6%) in group 1, 5 (35.7%) in group 2, and 7 (46.7%) in group 3. Of 43 patients, 41 (95.3%) were treated in 2 endoscopic sessions (95.3%), and 2 patients (4.7%) were treated in 3 endoscopic sessions. Uterine perforations occurred in 2 patients (4.7%), and cervical tears in 3 (7.0%). Ten patients (23.3%) achieved pregnancy, 8 (80%) after amnion graft and 2 (20%) without amnion. Six of the 10 patients (60%) miscarried, and 4 (40%) were either still pregnant or delivered at term without complications.

CONCLUSION: Hysteroscopic lysis of severe intrauterine adhesions with grafting of either fresh or dried amnion is a promising adjunctive procedure for decreasing recurrence of adhesions and encouraging endometrial regeneration.

Copyright © 2010 AAGL. Published by Elsevier Inc. All rights reserved.
PMID: 20576472 [PubMed – indexed for MEDLINE]

 

Human vital amniotic membrane reduces adhesions in experimental intraperitoneal onlay mesh repair (download)

Surg Endosc. 2011 Jul;25(7):2125-31. doi: 10.1007/s00464-010-1507-y. Epub 2010 Dec 10.

Petter-Puchner AH1, Fortelny RH, Mika K, Hennerbichler S, Redl H, Gabriel C.
1Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austrian Cluster for Tissue Regeneration, Vienna, Austria.

Abstract

BACKGROUND: Various antiadhesive coatings have been proposed for intraperitoneal onlay meshes (IPOM). However, adhesions, mesh infections, and impaired integration remain clinically relevant problems. In this experiment, human vital amniotic membrane (AM) was tested as antiadhesive mesh coating. Vital AM complies with clinical standards of product safety.

METHODS: In this study, 24 rats were randomized to one control or two treatment groups (n=8). An uncoated polypropylene mesh (Vitamesh) was implanted using open IPOM technique and fixed with four sutures. In the treatment groups, vital AM was attached to Vitamesh by fibrin sealant fixation. The observation period was 7 and 17 days. Vitamesh fixed by suture only served as the control condition (17 days). Adhesion formation, tissue integration, and neovascularization were assessed macroscopically and histologically.

RESULTS: All the meshes in the control group elicited severe adhesions. Vital AM was highly efficient in reducing adhesions to mesh and sutures. No foreign body reaction or unfavorable immunologic response to vital AM occurred. Tissue integration and neovascularization of coated meshes were good. Fibrin sealant yielded a reliable fixation.

CONCLUSION: Human vital AM was highly effective in reducing adhesions to polypropylene mesh and sutures in experimental IPOM. No adverse effects were detected, and tissue integration of the mesh was good.

PMID: 21153481 [PubMed – indexed for MEDLINE]

 

Vaginoplasty Using Amnion (download)

Obstet Gynecol. 1986 Mar;67(3):443-6.

Ashworth MF, Morton KE, Dewhurst J, Lilford RJ, Bates RG.

Abstract
Fifteen patients with various developmental and acquired abnormalities of the vagina were treated by the application of human amnion over a mold after surgical dissection of a space for the new vagina or enlargement of an existing but strictured one. Excellent results were achieved in cases of complete and partial vaginal agenesis, and there was improvement in all of the patients with vaginal strictures.

PMID: 3945456 [PubMed – indexed for MEDLINE]

 

Urology

Early experience in reconstruction of long ureteral strictures with allogenic amniotic membrane (download)

Int J Urol. 2007 Jul;14(7):607-10.

Koziak A1, Salagierski M, Marcheluk A, Szcześniewski R, Sosnowski M.
1Urology Department, Specialized Regional Hospital in Siedlce, Siedlce, Poland.

Abstract

OBJECTIVE: To present our experience with the application of human amniotic membrane for the reconstruction of extensive ureteral wall defects.

METHODS: Between 2003 and 2006, 11 patients underwent reconstructive surgery of the ureter. A human amniotic membrane allograft was used to supplement ureteral wall defects. Indications for the procedure included ureteral strictures of a 5.5 cm average (range, 3-8 cm) localized in different parts of the ureter: upper (5), middle (5) and lower (3). The etiology of ureteral loss was: postinflammatory after a complicated stone disease (5), iatrogenic (4) and idiopathic (2). Diagnosis of ureteral stricture was based on antegrade pyelography and excretory urography. Two patients had synchronous treatment for upper and middle ureteral stenosis. Treatment efficacy was assessed by excretory urography and ultrasound.

RESULTS: The mean hospitalization time was 11.9 days, mean operation time 128 min and with an average follow up of 25.2 months. Complications included: stricture recurrence (1) and symptomatic urinary tract infections (2). Excretory urography showed lack of obstruction and normal width of ureters. In one patient, residual hydronephrosis was present on ultrasound.

CONCLUSIONS: The described method seems to be a promising tool in the reconstruction of extensive ureteral strictures.

PMID: 17645603 [PubMed – indexed for MEDLINE]

 

Ophthalmology

The amniotic membrane in ophthalmology (download)

Surv Ophthalmol. 2004 Jan-Feb;49(1):51-77.

Dua HS1, Gomes JA, King AJ, Maharajan VS.
1Division of Ophthalmology and Visual Sciences, University of Nottingham, Nottingham, UK.

Abstract
The amniotic membrane is the innermost of the three layers forming the fetal membranes. It was first used in 1910 in skin transplantation. Thereafter it has been used in surgical procedures related to the genito-urinary tract, skin, brain, and head and neck, among others. The first documented ophthalmological application was in the 1940s when it was used in the treatment of ocular burns. Following initial reports, its use in ocular surgery abated until recently when it was re-discovered in the Soviet Union and South America. Its introduction to North America in the early 1990s heralded a massive surge in the ophthalmic applications of this membrane. The reintroduction of amniotic membrane in ophthalmic surgery holds great promise; however, although it has been shown to be a useful and viable alternative for some conditions, it is currently being used far in excess of its true useful potential. In many clinical situations it offers an alternative to existing management options without any distinct advantage over the others. Further studies will undoubtedly reveal the true potential of the membrane, its mechanism(s) of action, and the effective use of this tissue in ophthalmology.

PMID: 14711440 [PubMed – indexed for MEDLINE]