Amniotic membrane in oral and maxillofacial surgery

Application of Fetal Membranes and Natural Materials for Wound and Tissue Repair

The human fetal membrane is a globally accepted biological biomaterial for wound and tissue repair and regeneration in numerous fields, including dermatology, ophthalmology, and more recently orthopedics, maxillofacial and oral surgery, and nerve regeneration. Both cells and matrix components of amnion and chorion are beneficial, releasing a diverse range of growth factors, cytokines, peptides, and soluble extracellular matrix components. Beside fetal membranes, numerous natural materials have also been reported to promote wound healing. The biological properties of these materials may potentiate the pro-healing action of fetal membranes. Comparison of such materials with fetal membranes has been scant, and their combined use with fetal membranes has been underexplored. This review presents an up-to-date overview of (i) clinical applications of human fetal membranes in wound healing and tissue regeneration; (ii) studies comparing human fetal membranes with natural materials for promoting wound healing; and (iii) the literature on the combined use of fetal membranes and natural pro-healing materials.

Clinical and Radiographic Evaluation of Mineral Trioxide Aggregate and Human Amniotic Membrane Pulpotomy in Primary Molars: A Randomized Clinical Trial

Objectives

To clinically and radiographically compare the outcomes of pulpotomy with mineral trioxide aggregate (MTA) and human amniotic membrane (HAM) in primary molar teeth at 1, 3, 6, and 12 months.

Materials and methods

The study was a randomized clinical trial with two arms. One arm consisted of participants whose pulpotomy was conducted using MTA, called group I, and the other arm, using HAM, was designated group II.

Results

Both MTA and HAM exhibited 100% clinical success. Also, there were no signs of external resorption, periapical bone destruction, or internal resorption in both the MTA and the HAM groups at all four time intervals in this study. However, periodontal ligament widening was seen in 30% of the participants in the MTA group at 1-month and at the 12-month follow-up, whereas in the HAM group, periodontal ligament widening was found to reduce significantly from 22.2% at 1-month to 11.1% at the 12-month follow-up.

Conclusion

The HAM exhibited favorable clinical and radiographic outcomes in the present study.

Clinical significance

Mineral trioxide aggregate is the most preferred choice as a pulpotomy agent for deciduous teeth. However, various drawbacks associated with MTA have been fueling the need for newer, effective agents. HAM is not only easily available, cost-effective, and easy to handle but also favors tissue regeneration. The positive outcome of the present study strongly advocates the use of HAM as an alternative to MTA for pulpotomy in primary teeth.

How to cite this article

Joseph EJ, Rao A, Mahabala KY, et al. Clinical and Radiographic Evaluation of Mineral Trioxide Aggregate and Human Amniotic Membrane Pulpotomy in Primary Molars: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2024;17(6):641-646.

Soft Tissue Substitutes in Periodontal and Peri-Implant Soft Tissue Augmentation: A Systematic Review

BACKGROUND

Different extracellular matrix (ECM)-based technologies in periodontal and peri-implant soft tissue augmentation have been proposed in the market. The present review compared the efficacy of soft tissue substitutes (STSs) and autogenous free gingival grafts (FGGs) or connective tissue grafts (CTGs) in mucogingival procedures to increase keratinized tissue (KT) width around teeth and implants.

METHODS

Two independent examiners performed an electronic search on MEDLINE and the Cochrane Library based on the following PICOS format: (P) adult patients; (I) soft tissue substitutes and FGGs/CTGs; (C) STSs vs. CTGs; STSs vs. FGGs; STSs vs control; (O) KT width gain; (S) systematic reviews, randomized controlled trials. Studies published before November 2023 were included.

RESULTS

Around teeth, all biomaterials showed superior performance compared to a coronally advanced flap (CAF) alone for treating gingival recessions. However, when compared to CTGs, acellular dermal matrices (ADMs) yield the most similar outcomes to the gold standard (CTGs), even though in multiple recessions, CTGs continue to be considered the most favorable approach. The use of STSs (acellular matrix or tissue-engineered) in combination with apically positioned flaps (APF) resulted in significantly less gain in KT width compared to that achieved with FGGs and APFs. Around dental implants, free gingival grafts were deemed more effective than soft tissue substitutes in enhancing keratinized mucosa width.

CONCLUSIONS

Based on the available evidence, questions remain about the alternative use of soft tissue substitutes for conventional grafting procedures using free gingival grafts or connective tissue grafts around teeth and implants.

Comparison of the effects of preservation methods on structural, biological, and mechanical properties of the human amniotic membrane for medical applications

Amniotic membrane (AM), the innermost layer of the placenta, is an exceptionally effective biomaterial with divers applications in clinical medicine. It possesses various biological functions, including scar reduction, anti-inflammatory properties, support for epithelialization, as well as anti-microbial, anti-fibrotic and angio-modulatory effects. Furthermore, its abundant availability, cost-effectiveness, and ethical acceptability make it a compelling biomaterial in the field of medicine. Given the potential unavailability of fresh tissue when needed, the preservation of AM is crucial to ensure a readily accessible and continuous supply for clinical use. However, preserving the properties of AM presents a significant challenge. Therefore, the establishment of standardized protocols for the collection and preservation of AM is vital to ensure optimal tissue quality and enhance patient safety. Various preservation methods, such as cryopreservation, lyophilization, and air-drying, have been employed over the years. However, identifying a preservation method that effectively safeguards AM properties remains an ongoing endeavor. This article aims to review and discuss different sterilization and preservation procedures for AM, as well as their impacts on its histological, physical, and biochemical characteristics.

Processing methods for human amniotic membrane as scaffold for tissue engineering with mesenchymal stromal human cells

Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function. The aims of this work were to compare chemically and physically processed human Amniotic Membranes (hAM) and analyze the cytocompatibility and proliferation rate (PR) of two primary human mesenchymal stromal cell lines, from different sources and donor conditions seeded over these scaffolds. The evaluated hAM processes were: cold shock to obtain a frozen amniotic membrane (FEAM) with remaining dead epithelial cells, denudation of hAM with trypsin for 20/10 min (DEAM20/10) or treatment with sodium dodecyl sulfate to decellularized hAM (DAM). All samples were sterilized with gamma radiation. The selection of the treated hAM to then generate composites was performed by scanning and transmission electron microscopy and characterization by X-ray diffraction, selecting DEAM10 and FEAM as scaffolds for cell seeding. Two sources of primary human stromal cells were used, both developed by our researchers, human Dental Pulp Stem Cells (hDPSC) from living donors and human Mesenchymal Stromal Cells (hMSC) from bone marrow isolated from brain dead donors. This last line of cells conveys a novel source of human cells that, to our knowledge, have not been tested as part of this type of construct. We developed four in vitro constructs without cytotoxicity signs and with different PR depending on the scaffolds and cells. hDPSC and hMSC grew over both FEAM and DEAM10, but DEAM10 allowed higher PR.

The Preparation and Clinical Efficacy of Amnion-Derived Membranes: A Review

Biological tissues from various anatomical sources have been utilized for tissue transplantation and have developed into an important source of extracellular scaffolding material for regenerative medicine applications. Tissue scaffolds ideally integrate with host tissue and provide a homeostatic environment for cellular infiltration, growth, differentiation, and tissue resolution. The human amniotic membrane is considered an important source of scaffolding material due to its 3D structural architecture and function and as a source of growth factors and cytokines. This tissue source has been widely studied and used in various areas of tissue repair including intraoral reconstruction, corneal repair, tendon repair, microvascular reconstruction, nerve procedures, burns, and chronic wound treatment. The production of amniotic membrane allografts has not been standardized, resulting in a wide array of amniotic membrane products, including single, dual, and tri-layered products, such as amnion, chorion, amnion-chorion, amnion-amnion, and amnion-chorion-amnion allografts. Since these allografts are not processed using the same methods, they do not necessarily produce the same clinical responses. The aim of this review is to highlight the properties of different human allograft membranes, present the different processing and preservation methods, and discuss their use in tissue engineering and regenerative applications.

Considerations for an ideal post-surgical wound dressing aligned with antimicrobial stewardship objectives: a scoping review

OBJECTIVE

Most surgical wounds heal by primary or secondary intention. Surgical wounds can present specific and unique challenges including wound dehiscence and surgical site infection (SSI), either of which can increase risk of morbidity and mortality. The use of antimicrobials to treat infection in these wounds is prevalent, but there is now an imperative to align treatment with reducing antimicrobial resistance and antimicrobial stewardship (AMS). The aim of this review was to explore the published evidence identifying general considerations/criteria for an ideal post-surgical wound dressing in terms of overcoming potential wound healing challenges (including infection) while supporting AMS objectives.

METHOD

A scoping review examining evidence published from 1954-2021, conducted by two authors acting independently. Results were synthesised narratively and have been reported in line with PRISMA Extension for Scoping Reviews.

RESULTS

A total of 819 articles were initially identified and subsequently filtered to 178 for inclusion in the assessment. The search highlighted six key outcomes of interest associated with post-surgical wound dressings: wound infection; wound healing; physical attributes related to comfort, conformability and flexibility; fluid handling (e.g., blood and exudate); pain; and skin damage.

CONCLUSION

There are several challenges that can be overcome when treating a post-surgical wound with a dressing, not least the prevention and treatment of SSIs. However, it is imperative that the use of antimicrobial wound dressings is aligned with AMS programmes and alternatives to active antimicrobials investigated.

Preparation of human amniotic membrane for transplantation in different application areas

The human amniotic membrane (hAM) is the inner layer of the placenta and plays protective and nutritional roles for the fetus during pregnancy. It contains multiple growth factors and proteins that mediate unique regenerative properties and enhance wound healing in tissue regeneration. Due to these characteristics hAM has been successfully utilized in ophthalmology for many decades. This material has also found application in a variety of additional therapeutic areas. Particularly noteworthy are the extraordinary effects in the healing of chronic wounds and in the treatment of burns. But hAM has also been used successfully in gynecology, oral medicine, and plastic surgery and as a scaffold for in vitro cell culture approaches. This review aims to summarize the different graft preparation, preservation and storage techniques that are used and to present advantages and disadvantages of these methods. It shows the characteristics of the hAM according to the processing and storage methods used. The paper provides an overview of the currently mainly used application areas and raises new application possibilities. In addition, further preparation types like extracts, homogenates, and the resulting treatment alternatives are described.

Profile of biological characterizations and clinical application of corneal stem/progenitor cells

Corneal stem/progenitor cells are typical adult stem/progenitor cells. The human cornea covers the front of the eyeball, which protects the eye from the outside environment while allowing vision. The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role. Corneal stem/progenitor cells include mainly corneal epithelial stem cells, corneal endothelial cell progenitors and corneal stromal stem cells. Since the discovery of corneal epithelial stem cells (also known as limbal stem cells) in 1971, an increasing number of markers for corneal stem/progenitor cells have been proposed, but there is no consensus regarding the definitive markers for them. Therefore, the identification, isolation and cultivation of these cells remain challenging without a unified approach. In this review, we systematically introduce the profile of biological characterizations, such as anatomy, characteristics, isolation, cultivation and molecular markers, and clinical applications of the three categories of corneal stem/progenitor cells.

Human Amniotic Membrane for the Treatment of Cryptoglandular Anal Fistulas

Background: Implantation of the amniotic membrane and their derivatives can have a beneficial effect on tissue repair and regeneration. We report for the first time the implant of an amniotic membrane in a patient affected by cryptoglandular anal fistula. Methods: A patch of human amniotic membrane was implanted in a female patient affected by an anterior transphincteric fistula. Following an accurate curettage of the anal fistula, the cryopreserved amniotic membrane was thawed and then washed in the operating room; one side of the membrane was transfixed with a resorbable suture thus creating an implantable fusiform patch. The membrane was subsequently implanted into the fistula tract from the external to the internal opening. The inner and outer parts of the membrane were then sutured to the internal and external fistula openings. Results: No intraoperative or postoperative complications occurred. The patient was discharged one day after the procedure after an uneventful hospitalization. At the 1-week, 1- and 3-month follow-up visits no pain (VAS 0) was referred by the patient and no inflammation was evident at the level of the previous external fistula opening. Conclusions: The implant of human amniotic membrane in a patient affected by cryptoglandular anal fistula was safely and easily performed. Moreover, future studies to assess the efficacy in the long-term follow-up are needed.

Surgical management of stage-2 medication-related osteonecrosis of the jaw with transplantation of human amniotic membrane: Preliminary results

Medication-related osteonecrosis of the jaw (MRONJ) is a drug adverse reaction. Seven osteonecrosis areas in 5 cases were treated with stage-2 MRONJ using human amniotic membrane (HAM) transplantation after sequestrectomy. Patients were evaluated in terms of infection (pain, erythema, and pus), mucosal coverage, and pain at 1, 2, 4, 8, and 12 weeks. Patients who showed improvement (total mucosal coverage, no sign of infection and pain) at the end of 12 weeks were followed up every 8 weeks. Also, radiographic examinations (panoramic radiography at every 8 weeks, cone-beam computed tomography at every 6 months) were performed to evaluate bone destruction. Complete mucosal closure was achieved in 6 necrosis sites. In only 1 patient, mucosal coverage was not achieved. No pain and infection relapse were observed during the follow-ups. HAM might be an effective material in terms of soft tissue healing and elimination of pain and infection for stage-2 MRONJ. Clinical Trials Registration Number: NCT04967963.

Chorion and amnion/chorion membranes in oral and periodontal surgery: A systematic review

The aim of this study was to perform a systematic review on the clinical applications where chorion membrane (CM) and amnion/chorion membrane (ACM) were used for oral tissue regeneration procedures. Selection of articles was carried out by two evaluators in Pubmed and Scopus databases, and Outcomes (PICO) method was used to select the relevant articles. Clinical studies reporting the use of CM or ACM for oral soft and hard tissue regeneration were included. The research involved 21 studies conducted on 375 human patients. Seven clinical applications of CM and ACM in oral and periodontal surgery were identified: gingival recession treatment, intrabony and furcation defect treatment, alveolar ridge preservation, keratinized gum width augmentation around dental implants, maxillary sinus membrane repair, and large bone defect reconstruction. CM and ACM were compared to negative controls (conventional surgeries without membrane) or to the following materials: collagen membranes, dense polytetrafluoroethylene membranes, platelet-rich fibrin membranes, amnion membranes, and to a bone substitute. Several studies support the use of CM and ACM as an efficient alternative to current techniques for periodontal and oral soft tissue regeneration procedures. However, further studies are necessary to increase the level of evidence and especially to demonstrate their role for bone regeneration.

Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case-control study

The aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24 months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30 days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30 days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p = 0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p = 0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use.

Closure of the radial forearm free flap donor site with split-thickness skin graft or amniotic membrane: A prospective randomized clinical study

The purpose of this study was to compare the clinical, aesthetic, and functional outcomes between amniotic membrane (test group) and split-thickness skin grafts (control group) used for radial forearm free flap defect closure. The primary outcome measurement for both groups was assessment of the defect closure healing process. In addition, aesthetic (Vancouver Scar Scale) and functional outcomes (skin sensitivity, hand/wrist functionality, grip strength) were evaluated. Fifty eligible patients with radial forearm free flap donor site defects were randomly assigned to two groups receiving either amniotic membrane (test group; n = 25) or split-thickness skin graft (control group; n = 25) for defect covering. Forty-seven of the 50 patients (n = 47) were able to be followed up for 6 months and showed a significantly longer healing process (p < 0.001) with amniotic membrane (64.5 ± 38.4 days; n = 24) than with split-thickness skin grafts (29.2 ± 8.9 days; n = 23); however, there were no differences in the prevalence of healing defects/dehiscence and/or wound infections. Forty-two of the 47 patients (21 in each group) were able to be continually followed up for 12 months, and showed no differences in terms of clinical outcome as well as the subjective and objective aesthetic and functional results evaluated. With regard to the clinical, aesthetic, and functional outcomes evaluated for radial forearm free flap defects, coverage with amniotic membrane offers an excellent alternative treatment approach, avoiding secondary induced donor site morbidity.

The Human Tissue-Engineered Cornea (hTEC): Recent Progress

Each day, about 2000 U.S. workers have a job-related eye injury requiring medical treatment. Corneal diseases are the fifth cause of blindness worldwide. Most of these diseases can be cured using one form or another of corneal transplantation, which is the most successful transplantation in humans. In 2012, it was estimated that 12.7 million people were waiting for a corneal transplantation worldwide. Unfortunately, only 1 in 70 patients received a corneal graft that same year. In order to provide alternatives to the shortage of graftable corneas, considerable progress has been achieved in the development of living corneal substitutes produced by tissue engineering and designed to mimic their in vivo counterpart in terms of cell phenotype and tissue architecture. Most of these substitutes use synthetic biomaterials combined with immortalized cells, which makes them dissimilar from the native cornea. However, studies have emerged that describe the production of tridimensional (3D) tissue-engineered corneas using untransformed human corneal epithelial cells grown on a totally natural stroma synthesized by living corneal fibroblasts, that also show appropriate histology and expression of both extracellular matrix (ECM) components and integrins. This review highlights contributions from laboratories working on the production of human tissue-engineered corneas (hTECs) as future substitutes for grafting purposes. It overviews alternative models to the grafting of cadaveric corneas where cell organization is provided by the substrate, and then focuses on their 3D counterparts that are closer to the native human corneal architecture because of their tissue development and cell arrangement properties. These completely biological hTECs are therefore very promising as models that may help understand many aspects of the molecular and cellular mechanistic response of the cornea toward different types of diseases or wounds, as well as assist in the development of novel drugs that might be promising for therapeutic purposes.

The Healing Effect of Amniotic Membrane in Laryngeal Defects in Rabbit Model

OBJECTIVE

Fibrosis and scar formation following laryngeal repairing is a major concern. This study evaluated the efficacy of applying amniotic membrane (AM) as a biologic dressing to reduce fibrosis and inflammation and promote cartilage repair.

STUDY DESIGN

Experimental animal study.

METHODS

Nine male white Dutch rabbits were selected. A standard defect (5 mm) was created in right and left thyroid lamina. In the right side, two layers of AM were applied while the left side was kept intact for future comparison. Histologic examination with criteria of inflammation, fibrosis, and cartilage regeneration was performed 2, 4, and 6 weeks following AM application. All procedures were done according to animal ethics rules.

RESULTS

Histologic and gross examination showed that AM application was able to reduce inflammation and fibrosis and improve cartilage regeneration significantly.

CONCLUSION

As a useful intervention, AM application can reduce inflammation and fibrosis and enhance cartilage regeneration, following laryngeal defect repair.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E527-E533, 2021.

Protection of an intraoral surgical wound with a new dressing: a randomised controlled clinical trial

Operations that involve the maxillofacial region often require intraoral incisions, and contamination of these wounds is common as a result of the presence of saliva, plaque, and food debris. Postoperative infection is therefore common. The aim of the study was to evaluate the clinical efficacy of an intraoral dressing material, Reso-Pac®, in improving postoperative comfort for patients and its effect on wound healing. One hundred patients who required removal of impacted mandibular third molars were recruited, and were randomised into two groups (50 in each). A standardised surgical technique was used for removal of the impacted teeth, and wounds were closed with sutures. Postoperatively, the study group was given Reso-Pac® dressing while the control group was not. Postoperative pain was measured using a visual analogue scale (VAS). Wound healing was assessed with the help of Landry's scale, and we also measured thermal sensitivity. Data were analysed using the paired t test. The results in the study group were significantly better than those in the control group (p<0.001). Reso-Pac® promoted wound healing and improved patients' comfort during the postoperative phase.

Application of Human Amniotic Membrane in Temporomandibular Joint Osteoarthritis

Human amniotic membrane (HAM) has recently been used as an interpositional material to prevent ankylosis or primary re-ankylosis after temporomandibular joint (TMJ) arthroplasty. Here, the authors describe an unusual case of a 32-year-old woman who presented with a noninflammatory degenerative osteoarthritis of the TMJ in which a HAM was placed following a high condylar arthroplasty and discectomy and show the clinicoradiological results. The procedure resulted in total pain relief and significant improvement in jaw movements. On the long-term follow-up computed tomography, complete remodeling of the glenoid fossa with formation of new ectopic bone was observed. While the application of a HAM can be an alternative procedure to prevent ankylosis when performing a discectomy and arthroplasty, this clinical report highlights the possibility that it can induce ectopic bone formation at this location.

Use of amniotic membrane for radial forearm free flap donor site coverage: clinical, functional and cosmetic outcomes

Objective

To evaluate the clinical, functional and aesthetic outcomes for radial forearm free flap (RFFF) donor sites covered with amniotic membrane (AM).

Material and methods

The healing process of patients with RFFF donor sites covered with AM was prospectively followed for 1 year. Additionally at the 12-month evaluation, objective scoring systems were used to assess the aesthetic (Vancouver scar scale, VSS: range 1–13) and functional outcome (skin sensibility, hand/wrist functionality [goniometer], grip strength [score 1 = excellent, 5 = poor]). By using a subjective rating system (score 1 = excellent, 5 = poor), the patient-reported aesthetic and functionality outcome was correlated with objective data analysis.

Results

Twenty-one out of 23 patients were followed for 12 months (dropout: 2 patients at 3 months). In 17/23 (73.9%) patients RFFF defect covered with AM showed an uneventful healing period (< 3 months). Prolonged healing periods (> 3 months < 6) for 6 patients (26.1%) were attributed to wound infections (4×), seroma (1×) and inflammation (1×). At the 1-year evaluation, there was a significant (p < 0.01) correlation between subjective (2.0 ± 0.71) and objective aesthetic scores (VVS 3.74 ± 2.18), and a successful grip strength (score 1.67 ± 0.86); however, thumb hyposensibility in 76.2% was seen. A high body mass index (BMI) was in conjunction with a negative (p = 0.012) and the use of antihypertensive medications provided positive effects (p = 0.041) on the aesthetic outcome.

Conclusion

RFFF donor site defects covered using AM show excellent clinical, aesthetic and functional outcome representing patient comorbidities (BMI, antihypertensive drugs) might affect the aesthetic outcome.

Clinical relevance

In relation to the excellent outcomes found, the use of AM offers an alternative treatment procedure for RFFF defect covering.

Comparative preclinical assessment of the use of dehydrated human amnion/chorion membrane to repair perforated sinus membranes

Purpose

The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits.

Methods

Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted.

Results

The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups.

Conclusions

dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

Extracellular matrix-based scaffolding technologies for periodontal and peri-implant soft tissue regeneration

The present article focuses on the properties and indications of scaffold-based extracellular matrix (ECM) technologies as alternatives to autogenous soft tissue grafts for periodontal and peri-implant plastic surgical reconstruction. The different processing methods for the creation of cell-free constructs resulting in preservation of the extracellular matrices influence the characteristics and behavior of scaffolding biomaterials. The aim of this review is to discuss the properties, clinical application, and limitations of ECM-based scaffold technologies in periodontal and peri-implant soft tissue augmentation when used as alternatives to autogenous soft tissue grafts.

Temporomandibular Joint Discectomy Followed by Disc Replacement Using Viable Osteochondral and Umbilical Cord Allografts Results in Improved Patient Outcomes

PURPOSE

The ideal surgical solution to reconstruct the temporomandibular joint (TMJ) disc after it has been removed has remained elusive. The major obstacle has been identifying a durable biocompatible material that will provide for restoration of TMJ function. The present study evaluated the outcomes of the interpositional implantation of a cryopreserved viable osteochondral allograft (CVOCA) combined with a viable cryopreserved umbilical cord tissue (vCUT) allograft after TMJ discectomy in patients with internal derangement and/or degenerative joint disease (DJD).

PATIENTS AND METHODS

We implemented a retrospective case series study and enrolled patients with DJD or disc displacement diagnosed using the Diagnostic Criteria of Temporomandibular Disorders, who had undergone interpositional CVOCA and vCUT implantation after TMJ discectomy. The primary outcome variable was pain, measured using a visual analog scale (VAS). The secondary outcomes variables included maximal incisal opening (MIO) and Glasgow Benefit Inventory (GBI) general subscale scores. The primary analysis compared the preoperative measures with those at the last follow-up visit. Descriptive and analytic statistics were computed to summarize the sample's characteristics and assess the pre- and postoperative differences.

RESULTS

The study sample included 9 patients with a mean age of 36 years, and 44% were men. The VAS scores had decreased significantly from 9.0 ± 2.0 to 3.0 ± 3.0 postoperatively (P = .001). The MIO had increased from 31 ± 5 to 36 ± 5 mm (P = .178). The average GBI general subscale score of 13 ± 46 for the 9 patients showed a trend toward improved quality of life and patient satisfaction with the surgery. The median postoperative follow-up at the time of our report was 15 months (interquartile range, 10; range, 2 to 27) without treatment-related complications.

CONCLUSIONS

The reported outcomes suggest that the interpositional implantation of CVOCA and vCUT after TMJ discectomy could be a solution for reducing TMJ-related pain and restoring TMJ function. Longer follow-up and prospective multicenter studies are warranted.

A quality improvement pilot assessment of the safety and associated outcomes of a viable cryopreserved umbilical tissue allograft as an adjunct surgical wrap in peroneus brevis tendon repair

Surgical tendon repairs of the lower extremity are frequently associated with post-operative (post-op) risks that result in poor patient outcomes. Initially, increased pain levels may contribute to extended post-op rehabilitation while the development of tissue adhesions and fibrosis limit long-term functionality through reduced range of motion. Several surgical methods describing incorporation of various augmentative graft materials in tendon repair exist. However, reports demonstrating technique and both short- and long-term patient outcomes are lacking. Recently, advances in tissue preservation technology have led to the commercialization of human placental allografts. Of these available allogeneic biomaterials, the components found in human placental membranes may provide anti-inflammatory, antimicrobial, anti-adhesive, and antifibrotic properties to benefit surgical outcomes.Here, the authors introduce and technically describe the use of a viable cryopreserved umbilical tissue (vCUT) (Stravix, Osiris Therapeutics, Inc., Columbia, MD) as a complementary surgical wrap in primary tendon repair, with particular focus on the peroneus brevis. A pilot study was undertaken to assess the safety and potential for secondary rehabilitative outcomes associated with the use of vCUT in 5 tendon repair cases. The use of vCUT as a surgical tendon wrap was evaluated via the following primary endpoints at post-op day 7:Secondary investigative endpoints included clinical and rehabilitative outcome measures for comparative pain reduction and transition times to both controlled ankle movement (CAM) boot and normal shoe ambulation.All patients were followed for an average of 24.15 months (range 16.75-26.5 months) after surgery. For primary safety measures, erythema, tenderness, drainage, heat, and swelling was absent in all 5 surgical sites. None of the patients required post-op use of narcotics past day 7. The potential for long-term rehabilitative improvement with adjunct use of vCUT was also demonstrated through reduced pain and reduced transition times to functional and non-assisted ambulation in normal shoewear as compared to historical controls managed without vCUT.This surgical technique is simple and safe for patients and preliminary findings have demonstrated favorable clinical and rehabilitative outcomes over historically observed controls.

Incorporating placental tissue in cord blood banking for stem cell transplantation

INTRODUCTION

Human term placenta is comprised of various tissues from which different cells can be obtained, including hematopoietic stem cells and mesenchymal stem/stromal cells (MSCs). Areas covered: This review will discuss the possibility to incorporate placental tissue cells in cord blood banking. It will discuss general features of human placenta, with a brief review of the immune cells at the fetal-maternal interface and the different cell populations isolated from placenta, with a particular focus on MSCs. It will address the question as to why placenta-derived MSCs should be banked with their hematopoietic counterparts. It will discuss clinical trials which are studying safety and efficacy of placenta tissue-derived MSCs in selected diseases, and preclinical studies which have proven their therapeutic properties in other diseases. It will discuss banking of umbilical cord blood and raise several issues for improvement, and the applications of cord blood cells in non-malignant disorders. Expert commentary: Umbilical cord blood banking saves lives worldwide. The concomitant banking of non-hematopoietic cells from placenta, which could be applied therapeutically in the future, alone or in combination to their hematopoietic counterparts, could exploit current banking processes while laying the foundation for clinical trials exploring placenta-derived cell therapies in regenerative medicine.

Human Amniotic Membrane: A Versatile Scaffold for Tissue Engineering

The human amniotic membrane (hAM) is a collagen-based extracellular matrix derived from the human placenta. It is a readily available, inexpensive, and naturally biocompatible material. Over the past decade, the development of tissue engineering and regenerative medicine, along with new decellularization protocols, has recast this simple biomaterial as a tunable matrix for cellularized tissue engineered constructs. Thanks to its biocompatibility, decellularized hAM is now commonly used in a broad range of medical fields. New preparation techniques and composite scaffold strategies have also emerged as ways to tune the properties of this scaffold. The current state of understanding about the hAM as a biomaterial is summarized in this review. We examine the processing techniques available for the hAM, addressing their effect on the mechanical properties, biodegradation, and cellular response of processed scaffolds. The latest in vitro applications, in vivo studies, clinical trials, and commercially available products based on the hAM are reported, organized by medical field. We also look at the possible alterations to the hAM to tune its properties, either through composite materials incorporating decellularized hAM, chemical cross-linking, or innovative layering and tissue preparation strategies. Overall, this review compiles the current literature about the myriad capabilities of the human amniotic membrane, providing a much-needed update on this biomaterial.

Decellularized amnion scaffold with activated PRP: a new paradigm dressing material for burn wound healing

Direct application of amnion has greater risk of immunological rejection and infection. Decellularization is an effective method to lower the risk of immune complications and infections. The bioreactor assembly with multiple cassettes was designed for decellurization of multiple amnions with different cell types simultaneously in single run. A detergent-based protocol was modified to remove all cellular components from amnion and diminish the DNA content to render it non-immunogenic. Amnion (n = 10) were treated with 2% sodium dodecyl sulphate (SDS), 5% dimethyl sulfoxide (DMSO) and 2% sodium deoxycholeate (SD). Decellularized amnion samples were analyzed by haematoxylin-eosin staining (HE), Alcian blue pH 1 (AB-pH-1), 4,6-diamnionidino-2-phenylindol (DAPI), Massion's trichrome stain, DNA quantification, mechanical testing and scanning electron microscopy (SEM). Histological analysis showed complete removal of cellular components and the histoarchitecture of scaffold remained intact. Amnion scaffold activated with platelet rich plasma (PRP) and calcium chloride composition supported better adherence to the wound than amnion alone. Only single application showed good healing. In vivo assessment of activated amnion revealed stable dressing. It has good promising outcome. At day 7, histologically the wounds treated with activated amnion were almost closed without scarring and showed well differentiated epidermis, proliferation of keratinocytes, hair follicles and basement membrane as compared to controls and silver nitrate gel dressings in a mouse (Mus musculus). Cryopreservation had no adverse effect on the mechanical properties of the amnion scaffold. Cryopreservation of decellularized amnion by Dulbecco's modified eagle medium (DMEM) was expected to prepare off-the-shelf skin substitutes and preserve them to be immediately available upon request of patients' needs.

Amniotic membrane in ophthalmology: properties, preparation, storage and indications for grafting-a review

The use of amniotic membrane in ophthalmic surgery and other surgical procedures in the fields of dermatology, plastic surgery, genitourinary medicine and otolaryngology is on the increase. Furthermore, amniotic membrane and its epithelial and mesenchymal cells have broad use in regenerative medicine and hold great promise in anticancer treatment. Amniotic membrane is a rich source of biologically active factors and as such, promotes healing and acts as an effective material for wound dressing. Amniotic membrane supports epithelialization and exhibits anti-fibrotic, anti-inflammatory, anti-angiogenic and anti-microbial features. Placentas utilised in the preparation of amniotic membrane are retrieved from donors undergoing elective caesarean section. Maternal blood must undergo serological screening at the time of donation and, in the absence of advanced diagnostic testing techniques, 6 months postpartum in order to cover the time window for the potential transmission of communicable diseases. Amniotic membrane is prepared by blunt dissection under strict aseptic conditions, then is typically transferred onto a nitrocellulose paper carrier, usually with the epithelial side up, and cut into multiple pieces of different dimensions. Amniotic membrane can be stored under various conditions, most often cryopreserved in glycerol or dimethyl sulfoxide or their mixture with culture medium or buffers. Other preservation methods include lyophilisation and air-drying. In ophthalmology, amniotic membrane is increasingly used for ocular surface reconstruction, including the treatment of persistent epithelial defects and non-healing corneal ulcers, corneal perforations and descemetoceles, bullous keratopathy, as well as corneal disorders with associated limbal stem cell deficiency, pterygium, conjunctival reconstruction, corneoscleral melts and perforations, and glaucoma surgeries.

Amniotic membrane and adipose-derived stem cell co-culture system enhances bone regeneration in a rat periodontal defect model

BACKGROUND/PURPOSE

Periodontal disease is a chronic inflammatory process that potentially leads to alveolar bone destruction and tooth loss. Tissue engineering combined with stem cell therapy is a potential effective treatment for periodontal bone loss. Amniotic membrane (AM) is a potential scaffold enriched with multiple growth factors. It has the effects of anti-inflammation, antiangiogenesis, and immunosuppression. Herein, we used adipose-derived stem cells (ADSCs) and an AM co-cultured system to study bone regeneration in a rat periodontal defect model in vivo.

METHODS

Human ADSCs were isolated from the infrapatellar fat pad, and characterized by flow cytometry, reverse transcription-polymerase chain reaction, and multipotent differentiation assays. The co-culture system was applied in the periodontal two-wall osseous defect in a rat model, and computed tomography was used to measure the effect.

RESULTS

Human ADSCs isolated from the infrapatellar fat pad showed spindle-like morphology. Flow cytometry results demonstrated that ADSCs expressed a high level of CD90 and CD105, but not CD31, CD34, and CD45. ADSCs strongly expressed stemness genes, including SOX2, OCT4, NANOG, and KLF4 on different passages. Furthermore, ADSCs were able to differentiate into osteogenic, chondrogenic, and adipogenic cells. In the periodontal osseous defect rat model, ADSCs and the AM co-culture system significantly increased bone regeneration.

CONCLUSION

This study provides the basis for using ADSCs with an AM co-culture system as stem cell therapy and scaffold transplantation in clinical periodontology.

Liver diseases: what is known so far about the therapy with human amniotic membrane?

Liver, the largest intern organ of the human body, is responsible for several vital tasks such as digestive and excretory functions, as well as for nutrients storage and metabolic functions, synthesis of new molecules and purification of toxic chemicals. Cirrhosis, fibrosis and hepatocellular carcinoma are the most prevalent liver diseases. Despite all the studies performed so far, treatment options for these diseases are very limited. For this reason, it is urgent to find effective therapies for these pathologies. Several studies have been performed during the last decade about the possible application of human amniotic membrane in hepatic diseases therapy. Promising results about human amniotic membrane or its derived cells, in vitro and in vivo, applications in fibrosis, cirrhosis and hepatocellular carcinoma were already published. Since it is an attractive study area, it is becoming a dynamic scientific subject. However, the action mechanisms of human amniotic membrane and its derived cells in hepatic diseases therapy must be precisely known in order that this promising therapy could be clinically used.

Effect of gamma radiation on the expression of mRNA growth factors in glycerol cryopreserved human amniotic membrane

Human amniotic membrane (HAM) due to its high biocompatibility, low immunogenicity, anti-microbial, anti-viral properties as well as the presence of growth factors has been used in various clinical applications. The growth factors play an important role in wound healing. The current study aimed to explore the effect of 15 kGy gamma radiation dose on selected growth factors and receptors mRNA present in HAM. Eight growth factors, namely, EGF, HGF, KGF, TGF-α, TGF-β1, TGF-β2, TGF-β3 and bFGF and two growth factor receptors, HGFR and KGFR were evaluated in this study. The total RNA was extracted and converted to complimentary DNA using commercial kits. Subsequently, the mRNA expressions of these growth factors were evaluated using real-time PCR and the results were statistically analyzed using REST-MCS software. This study confirmed the presence of these mRNA growth factors and receptors in fresh, glycerol cryopreserved and irradiated glycerol cryopreserved HAM. In glycerol cryopreserved HAM, the results showed up-regulation of HGF and bFGF and down-regulation of EGF, HGFR, KGF, KGFR, TGF-α, TGF-β1, TGF-β2 and TGF-β3 relative to the fresh HAM which acted as the control, whereas in irradiated glycerol cryopreserved HAM, the results showed up-regulation of EGF, HGF, KGF, KGFR, TGF-β1, TGF-β2 and TGF-β3 and down-regulation of HGFR, TGF-α and bFGF relative to the glycerol cryopreserved HAM which acted as the control. However, these mRNA expressions did not show any statistical significant difference compared to the control groups. This study concluded that a dose of 15 kGy of gamma radiation did not affect the mRNA expression for the growth factors' and receptors' in the glycerol cryopreserved HAM.

Acute and Chronic Ophthalmic Involvement in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis - A Comprehensive Review and Guide to Therapy. II. Ophthalmic Disease

Our purpose is to comprehensively review the state of the art with regard to Stevens- Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with particular attention to improving the management of associated ocular surface complications. SJS and TEN are two ends of a spectrum of immune-mediated disease, characterized in the acute phase by a febrile illness followed by skin and mucous membrane necrosis and detachment. Part I of this review focused on the systemic aspects of SJS/TEN and was published in the January 2016 issue of this journal. The purpose of Part II is to summarize the ocular manifestations and their management through all phases of SJS/TEN, from acute to chronic. We hope this effort will assist ophthalmologists in their management of SJS/TEN, so that patients with this complex and debilitating disease receive the best possible care and experience the most optimal outcomes in their vision and quality of life.

New Amniotic Membrane Based Biocomposite for Future Application in Reconstructive Urology

Objective

Due to the capacity of the amniotic membrane (Am) to support re-epithelisation and inhibit scar formation, Am has a potential to become a considerable asset for reconstructive urology i.e., reconstruction of ureters and urethrae. The application of Am in reconstructive urology is limited due to a poor mechanical characteristic. Am reinforcement with electrospun nanofibers offers a new strategy to improve Am mechanical resistance, without affecting its unique bioactivity profile. This study evaluated biocomposite material composed of Am and nanofibers as a graft for urinary bladder augmentation in a rat model.

Material and Methods

Sandwich-structured biocomposite material was constructed from frozen Am and covered on both sides with two-layered membranes prepared from electrospun poly-(L-lactide-co-E-caprolactone) (PLCL). Wistar rats underwent hemicystectomy and bladder augmentation with the biocomposite material.

Results

Immunohistohemical analysis (hematoxylin and eosin [H&E], anti-smoothelin and Masson’s trichrome staining [TRI]) revealed effective regeneration of the urothelial and smooth muscle layers. Anti-smoothelin staining confirmed the presence of contractile smooth muscle within a new bladder wall. Sandwich-structured biocomposite graft material was designed to regenerate the urinary bladder wall, fulfilling the requirements for normal bladder tension, contraction, elasticity and compliance. Mechanical evaluation of regenerated bladder wall conducted based on Young’s elastic modulus reflected changes in the histological remodeling of the augmented part of the bladder. The structure of the biocomposite material made it possible to deliver an intact Am to the area for regeneration. An unmodified Am surface supported regeneration of the urinary bladder wall and the PLCL membranes did not disturb the regeneration process.

Conclusions

Am reinforcement with electrospun nanofibers offers a new strategy to improve Am mechanical resistance without affecting its unique bioactivity profile.

Biological Activity Alterations of Human Amniotic Membrane Pre and Post Irradiation Tissue Banking

BACKGROUND AND OBJECTIVE

Innate immunity of Human Amniotic Membrane (HAM) and its highly active secretome that rich with various types of growth factors and anti-inflammatory substances proposed it as a promising material for many medical studies and applications.

METHODOLOGY

This study evaluate the biological activity of cultivated HAM pre and post tissue banking process in which freeze-dried HAM was sterilized by 25 KGray (kGy) dose of γ radiation. The HAM's antimicrobial activity, viability, growth of isolated human amniotic epithelial cells (HAECs), hematopoietic stimulation of co-cultivated murine bone marrow cells (mammalian model), scaffold efficiency for fish brain building up (non-mammalian model) and self re-epithelialization after trypsin denuding treatment were examined as supposed biological activity features.

RESULTS

Native HAM revealed viability indications and was active to kill all tested microorganisms; 6 bacterial species (3 Gram-positive and 3 Gram-negative) and Candida albicans as a pathogenic fungus. Also, HAM activity promoted colony formation of murine hematopoietic cells, Tilapia nilotica brain fragment building-up and self re-epithelialization after trypsin treatment. In contrary, radiation-based tissue banking of HAM caused HAM cellular death and consequently lacked almost all of examined biological activity features.

CONCLUSION

Viable HAM was featured with biological activity than fixed HAM prepared by irradiation tissue banking.

A Novel Approach to Penile Augmentation Urethroplasty Using Buccal Mucosa and Amniotic Membrane: A Pilot Study in a Rabbit Model

OBJECTIVE

To evaluate and compare the success of amniotic membrane (AM) and buccal mucosa (BM) grafts and simultaneous use of both in penile augmentation urethroplasty in rabbits.

MATERIALS AND METHODS

A total of 12 New Zealand rabbits were divided into 3 groups by grafting style: Group 1 (AM), Group 2 (BM), and Group 3 (simultaneous use of BM and AM). In all animals, a standardized urethral defect was created. BM and AM were obtained from the rabbits. Solely AM grafts were affixed to the defects in Group 1, solely BM grafts were affixed to the urethral defects in Group 2, and simultaneous AM + BM grafts were affixed in Group 3. At 4 and 8 weeks, the penises were subject to histological assessment of subepithelial fibrosis, epithelial transformation, and inflammatory reaction.

RESULTS

Stenosis was detected in none of the groups. A dehiscence was developed in one rabbit in Group 1 and a fistula was developed in one rabbit in Group 2. After 4 weeks, minimal subepithelial fibrosis and inflammatory reaction were observed in Group 2, while subepithelial fibrosis was not in Groups 3. After 8 weeks, subepithelial connective tissue proliferation was moderate in Group 2, at both 4th and 8th weeks in Group 2. After 8 weeks, the best epithelial transformations were observed in Group 3.

CONCLUSION

In an animal model, the simultaneous use of AM and BM grafts following acute urethral injury may be feasible for penile augmentation urethroplasty. Further study is needed.

The Long Path of Human Placenta, and Its Derivatives, in Regenerative Medicine

In the 1800s, a baby born with a caul, a remnant of the amniotic sack or fetal membranes, was thought to be lucky, special, or protected. Over time, fetal membranes lost their legendary power and were soon considered nothing more than biological waste after birth. However, placenta tissues have reclaimed their potential and since the early 1900s an increasing body of evidence has shown that these tissues have clinical benefits in a wide range of wound repair and surgical applications. Nowadays, there is a concerted effort to understand the mechanisms underlying the beneficial effects of placental tissues, and, more recently, cells derived thereof. This review will summarize the historical and current clinical applications of human placental tissues, and cells isolated from these tissues, and discuss some mechanisms thought to be responsible for the therapeutic effects observed after tissue and/or cell transplantation.

Autologous transplantation of oral mucosal epithelial cell sheets cultured on an amniotic membrane substrate for intraoral mucosal defects

The human amniotic membrane (AM) is a thin intrauterine placental membrane that is highly biocompatible and possesses anti-inflammatory and anti-scarring properties. Using AM, we developed a novel method for cultivating oral mucosal epithelial cell sheets. We investigated the autologous transplantation of oral mucosal epithelial cells cultured on AM in patients undergoing oral surgeries. We obtained specimens of AM from women undergoing cesarean sections. This study included five patients without any history of a medical disorder who underwent autologous cultured oral epithelial transplantation following oral surgical procedures. Using oral mucosal biopsy specimens obtained from these patients, we cultured oral epithelial cells on an AM carrier. We transplanted the resultant cell sheets onto the oral mucosal defects. Patients were followed-up for at least 12 months after transplantation. After 2–3 weeks of being cultured on AM, epithelial cells were well differentiated and had stratified into five to seven layers. Immunohistochemistry revealed that the cultured cells expressed highly specific mucosal epithelial cell markers and basement membrane proteins. After the surgical procedures, no infection, bleeding, rejection, or sheet detachment occurred at the reconstructed sites, at which new oral mucous membranes were evident. No recurrence was observed in the long-term follow-up, and the postoperative course was excellent. Our results suggest that AM-cultured oral mucosal epithelial cell sheets represent a useful biomaterial and feasible method for oral mucosal reconstruction. However, our primary clinical study only evaluated their effects on a limited number of small oral mucosal defects.

The use of temporalis muscle graft, fresh and cryopreserved amniotic membrane in preventing temporomandibular joint ankylosis after discectomy in rabbits

PURPOSE

The aim of the study was to evaluate the efficacy of temporalis muscle-fascia graft, fresh and cryopreserved human amniotic membrane as an interpositional material in preventing temporomandibular joint ankylosis in a rabbit model.

MATERIALS AND METHODS

In this experimental study, 21 New Zealand white rabbits were used. The condyle and the joint disc were removed to induce ankylosis in left TMJs. Reconstruction was immediately performed with temporalis muscle-fascia graft (tMFG) in group I (n = 7), fresh human amniotic membrane (fHAM) in group II (n = 7) and cryopreserved human amniotic membrane (cHAM) in group III (n = 7). All rabbits were sacrificed at 3 months after the operation. The comparison was made among three groups by means of vertical mouth opening and weight measurements, radiologic and histologic findings obtained before and after surgery.

RESULTS

In all rabbits, there was no statistically significant difference in the jaw movements and weight among groups at commencement and 3 months after surgery. The condylar surfaces were more irregular in HAM groups. There were mild osteophyte formations, sclerosis, fibrosis and calcification around the condyle in all groups however the joint gap was more preserved in group I. All interpositional materials were also seen to be partially present in the joint gap at 3 months. Ankylosis was not seen in the joint gap in any group.

CONCLUSION

With the results of this study it was concluded that interpositional arthroplasty with HAM and tMFG have an almost similar effect in preventing TMJ ankylosis after discectomy in the rabbit model.

In vitro development and characterization of a tissue-engineered conduit resembling esophageal wall using human and pig skeletal myoblast, oral epithelial cells, and biologic scaffolds

INTRODUCTION

Tissue engineering represents a promising approach for esophageal replacement, considering the complexity and drawbacks of conventional techniques.

AIM

To create the components necessary to reconstruct in vitro or in vivo an esophageal wall, we analyzed the feasibility and the optimal conditions of human and pig skeletal myoblast (HSM and PSM) and porcine oral epithelial cell (OEC) culture on biologic scaffolds.

MATERIALS AND METHODS

PSM and HSM were isolated from striated muscle and porcine OECs were extracted from oral mucosa biopsies. Myoblasts were seeded on an acellular scaffold issue from porcine small intestinal submucosa (SIS) and OEC on decellularized human amniotic membrane (HAM). Seeding conditions (cell concentrations [0.5×10(6) versus 10(6) cells/cm(2)] and culture periods [7, 14 and 21 days]), were analyzed using the methyl thiazoltetrazolium assay, quantitative PCR, flow cytometry, and immunohistochemistry.

RESULTS

Phenotypic stability was observed after cellular expansion for PSM and HSM (85% and 97% CD56-positive cells, respectively), and OECs (90% AE1/AE3- positive cells). After PSM and HSM seeding, quantities of viable cells were similar whatever the initial cell concentration used and remained stable at all time points. During cell culture on SIS, a decrease of CD56-positive cells was observed (76% and 76% by D7, 56% and 70% by D14, 28% and 60% by D21, for PSM and HSM, respectively). Multilayered surface of α-actin smooth muscle and Desmine-positive cells organized in bundles was seen as soon as D7, with no evidence of cell within the SIS. Myoblasts fusion was observed at D21. Pax3 and Pax7 expression was downregulated and MyoD expression upregulated, at D14.OEC proliferation was observed on HAM with both cell concentrations from D7 to D21. The cell metabolism activity was more important on matrix seeded by 10(6) cells/cm(2). With 0.5×10(6) OEC/cm(2), a single layer of pancytokeratin-positive cells was seen at D7, which became pluristratified by D14, while when 10(6) OEC/cm(2) were used, a pluristratified epithelial structure was seen as soon as D7. Proliferative cells (Proliferating Cell Nuclear Antigen staining) were mainly located at the basal layer.

CONCLUSION

In this model, the optimal conditions of cell seeding in terms of cell concentration and culture duration were 0.5×10(6) myoblasts/cm(2) and 10(6) OEC/cm(2), and 7 days.