Human amnion-derived mesenchymal stem cells improve subclinical hypothyroidism by immunocompetence mediating apoptosis inhibition on thyroid cells in aged mice

Subclinical hypothyroidism (SCH) affects 10% of the global population, which is most prevalent in women and the elderly. However, it remains debatable whether the elderly with subclinical hypothyroidism needs thyroxine supplement. Human amnion-derived mesenchymal stem cells (hAMSCs) could play important roles in autoimmune diseases, suggesting that hAMSC be a candidate to regulate the thyroid function of female age-related subclinical hypothyroidism. Herein, we established the model of SCH in the aged female mice. This study was designed to investigate whether human amnion-derived mesenchymal stem cells (hAMSC) could effect on immune regulation, apoptosis inhibition of thyroid cells, thyroid function, blood lipid levels, and heart function. In addition, qualified hAMSCs were intravenously injected into aged female SCH mice via the tail vein on day 0 and day 10. The levels of thyroid hormone and blood lipids as well as cardiac function, serum immunological indexes, and apoptosis of thyroid cells were then analyzed on day 5, 10, 15, and 20; meanwhile, the quantity of Th1, Th2, Th17, and Treg immune cells in peripheral blood was evaluated before and on day 20 post-injection. Our study demonstrated that after hAMSC transplantation, the thyroid functions, blood lipid levels, and heart function indexes of age-related SCH (AR-SCH) mice were significantly improved. Consistent with this, Th1 and Treg cells increased significantly, while Th2 and Th17 cells decreased in peripheral blood. Apoptosis was also suppressed in the thyroid cells. In summary, hAMSC delivery can potentially be a safe and effective therapy for treating SCH in the elderly, improving related complications by immunomodulatory and apoptosis inhibition.

MACULAR HOLE HYDRODISSECTION TECHNIQUE WITH HUMAN AMNIOTIC MEMBRANE FOR REPAIR OF LARGE MACULAR HOLES

PURPOSE

To describe a combined surgical technique using the macular hole hydrodissection (MHH) with human amniotic membrane for repair of large macular holes.

METHODS

A step-by-step procedure and a surgical video using the combined MHH and human amniotic membrane technique are presented.

DESCRIPTION AND TECHNIQUE

As the first step, the MHH separates the adhesions of the macular hole to the underlying retinal pigment epithelium with a soft-tipped cannula through proportional reflux followed by gentle passive aspiration. The human amniotic membrane graft is marked to identify the nonsticky epithelial side and ensure that the stromal layer (sticky and nonshinny) is facing downward toward the retinal pigment epithelium. The graft is then tucked into the space created with MHH between the macular hole edges and the retinal pigment epithelium with closed forceps to decrease the likelihood of the graft from dislocating postoperatively.

CONCLUSION

The MHH in combination with the human amniotic membrane is a practical and effective technique for addressing challenging large macular holes.

In vitro antibacterial efficacy of autologous conditioned plasma and amniotic membrane eye drops

OBJECTIVE

To determine the in vitro antibacterial efficacy of equine and canine autologous conditioned plasma (ACP) and amniotic membrane extract eye drops (AMEED) against aerobic bacteria common to the corneal surface.

PROCEDURES

Canine (n = 4) and equine (n = 4) anticoagulated whole blood samples were sterilely collected, pooled for each species, and processed using the Arthrex ACP® Double-Syringe System. Platelet counts were performed on ACP and pooled blood. AMEED were obtained from a commercial source. An electronic medical records search (2013-2022) identified aerobic bacteria cultured from canine and equine corneal ulcers at Mississippi State University College of Veterinary Medicine (MSU-CVM). Ten commonly isolated bacteria for each species were collected from cultures submitted to the MSU-CVM Microbiology Diagnostic Service and frozen at -80°C. The Kirby-Bauer disk diffusion method was used to determine the sensitivities of these isolates to ACP and AMEED. Bacterial isolates were plated onto Mueller-Hinton +5% sheep blood agar and blank sterile discs saturated with 20 μL of ACP or AMEED were tested in duplicate. Imipenem discs served as positive controls and blank discs as negative controls. Zones of inhibition were measured at 18 h.

RESULTS

ACP platelet counts were 1.06 and 1.65 times higher than blood for equine and canine samples, respectively. Growth of a multi-drug resistant Enterococcus faecalis was partially inhibited by canine and equine ACP. AMEED did not inhibit growth of any examined bacteria.

CONCLUSIONS

Canine and equine ACP partially inhibited E. faecalis growth in vitro. Further studies using varying concentrations of ACP against bacterial isolates from corneal ulcers are warranted.

REPAIR OF THE EXIT WOUND OF A PERFORATING GLOBE INJURY WITH THE AMNIOTIC MEMBRANE: A SURGICAL ADJUVANT FOR EARLY VITRECTOMY

PURPOSE

To describe the use of the amniotic membrane for the repair of the exit wound of a perforating injury involving the retina and the choroid.

METHODS

Case report.

RESULTS

A 46-year-old man presented one day after a perforating ocular injury with an exit wound close to the inferior temporal retinal vascular arcade. The next day, the patient underwent a combined vitrectomy and phacoemulsification with intraocular lens implantation. During vitrectomy, a retinochoroidectomy was performed at the exit wound and the internal limiting membrane was peeled over the macula and up to the exit wound. Laser retinopexy was followed by plugging of a piece of the amniotic membrane to the exit wound. A second piece of the amniotic membrane was used to cover the bare retinochoroidectomy area. The surgery was concluded with a silicone exchange. Postoperatively, no sign of proliferative vitreoretinopathy was observed, and at 3 months, the silicone oil was removed. The follow-up was uneventful, and the eye achieved a final visual acuity of 20/30.

CONCLUSION

The amniotic membrane may offer a simple and safe solution for the repair of the exit wounds of perforating injuries involving the retina and the choroid. The use of the amniotic membrane for this purpose may afford the opportunity for early vitrectomy in the management of perforating ocular injuries.

Improvement in growth performance and digestive function from amniotic injections of N-acetylglutamate in broiler chickens

BACKGROUND

N-acetylglutamate (NAG) is the initial and essectial substrate in the process of de novo arginine synthesis, plays an important role in intestinal development. The aim of this study was to determine the effects of in ovo feeding of NAG, 1.5 mg/egg at 17.5 days of incubation (DOI) via amnion, on hatching performance, early intestinal histomorphometry, jejunal barrier, digestive function, and growth performance of broiler chickens between 1 and 14 days of age.

RESULTS

Amniotic injection of NAG had no significant effect on hatching characteristics compared with the non-injected control group (NC group). Birds in the NAG solution-injected group (NAG group) exhibited lower average daily feed intake and better feed efficiency during a period of 1-14 days. In comparison with the NC group, the NAG group had decreased crypt depth (CD) in the ileum and increased villus height (VH) / CD in the jejunum at 7 days, and decreased CD in duodenum and significantly increased VH in the jejunum at 14 days. However, the effects of in ovo supplementation with NAG on the density of goblet cells, and gene expression of mucin 2 and alkaline phosphatase were not significant. Chicks in the NAG group had a significantly higher mRNA expression level of trypsin and maltase in jejunum at 7 days than the NC group but not at 14 days.

CONCLUSION

Amniotic injections of NAG (1.5 mg/egg) at 17.5 DOI could improve early growth performance of broilers during 1-14 days after hatching by accelerating the development of the intestine and enhancing jejunal digestive function. © 2023 Society of Chemical Industry.

Retention of Key Characteristics of Unprocessed Chorion Tissue Resulting in a Robust Scaffold to Support Wound Healing

Placental membranes have been widely studied and used clinically for wound care applications, but there is limited published information on the benefits of using the chorion membrane. The chorion membrane represents a promising source of placental-derived tissue to support wound healing, with its native composition of extracellular matrix (ECM) proteins and key regulatory proteins. This study examined the impact of hypothermic storage on the structure of chorion membrane, ECM content, and response to degradation in vitro. Hypothermically stored chorion membrane (HSCM) was further characterized for its proteomic content, and for its functionality as a scaffold for cell attachment and proliferation in vitro. HSCM retained the native ECM structure, composition, and integrity of native unprocessed chorion membrane and showed no differences in response to degradation in an in vitro wound model. HSCM retained key regulatory proteins previously shown to be present in placental membranes and promoted the attachment and proliferation of fibroblasts in vitro. These data support the fact that hypothermic storage does not significantly impact the structure and characteristics of the chorion membrane compared to unprocessed tissue or its functionality as a scaffold to support tissue growth.

[Human amniotic membrane plug for recurrent retinal detachment associated with pathologic myopic macular hole]

A 60-year-old woman presented with a history of "pathological myopia combined with macular hole retinal detachment, " for which she underwent vitrectomy, internal limiting membrane tamponade, and silicone oil filling surgery one year ago. Seven months ago, the silicone oil was removed. She now returned to seek medical attention as her visual acuity has declined by 10 diopters. Examination revealed a recurrence of macular hole retinal detachment. The patient was treated with combined amniotic membrane tamponade and silicone oil filling. During the surgery, the frozen amniotic membrane was cut into 2 mm × 2 mm and placed under the macular hole retina after silicone oil filling. Within 6 months after the surgery, her retina repositioned well, the macular hole closed, and her visual function improved from hand motion to 0.05. No severe complications were observed. Therefore, this surgical approach provides a new perspective for treating recurrent pathological myopia combined with macular hole retinal detachment.

Amniotic membrane and/or umbilical cord tissue for treatment of facet joint syndrome: a narrative review

Musculoskeletal spine disorders, especially low back pain, induce enormous amounts of stress and financial burden on individuals and healthcare systems throughout the world. Disorders of the facet joints in the lumbar spine are the most predominant cause of back pain, resulting in facet joint syndrome (FJS). Conventional treatments for FJS are short-lived and have limitations and side effects. Thus, safer and more effective alternatives that can reduce pain and improve patient-reported outcomes are needed. Recently, the utilization of biologics, including the ones derived from perinatal tissue such as amniotic membrane (AM) and umbilical cord (UC), has significantly increased for regenerative medicine applications. This manuscript summarizes the outcomes of preclinical and clinical studies utilizing AM and/or UC for FJS. We identified no preclinical studies and 3 retrospective studies utilizing the search terms "amniotic membrane" and/or "umbilical cord" and "facet joint syndrome". The administration of AM + UC is safe and potentially efficacious for patients with FJS. However, more preclinical studies and appropriately powered, multi-center, prospective non-randomized and randomized controlled studies with longer follow-up are warranted to further evaluate the efficacy of AM + UC to justify its clinical use.

Modeling an ascending infection by Ureaplasma parvum and its cell signaling and inflammatory response at the feto-maternal interface

PROBLEM

Ascending bacterial infection is associated with ∼ 40% of spontaneous preterm birth (PTB), and Ureaplasma spp. is one of the most common bacteria isolated from the amniotic fluid. Developing novel in vitro models that mimic in vivo uterine physiology is essential to study microbial pathogenesis. We utilized the feto-maternal interface organ-on-chip (FMi-OOC) device and determined the propagation of Ureaplasma parvum, and its impact on cell signaling and inflammation.

METHOD OF STUDY

FMi-OOC is a microphysiologic device mimicking fetal membrane/decidua interconnected through microchannels. The impact of resident decidual CD45+ leukocytes was also determined by incorporating them into the decidual chamber in different combinations with U. parvum. We tested the propagation of live U. parvum from the decidual to the amniochorion membranes (immunocytochemistry and quantitative PCR), determined its impact on cytotoxicity (LDH assay), cell signaling (JESSTM Western Blot), cellular transition (immunostaining for vimentin and cytokeratin), and inflammation (cytokine bead array).

RESULTS

U. parvum transversed the chorion and reached the amnion epithelium after 72 hours but did not induce cell signaling kinases (p38MAPK and JNK) activation, or cellular transition (epithelial-mesenchymal), regardless of the presence of immune cells. The inflammatory response was limited to the choriodecidual interface and did not promote inflammation in the amnion layer.

CONCLUSIONS

Our data suggest that U. parvum is poorly immunogenic and does not produce massive inflammatory changes at the feto-maternal interface. We speculate that the presence of U. parvum may still compromise the feto-maternal interface making it susceptible to other pathogenic infection.

Emerging Strategies for the Biofabrication of Multilayer Composite Amniotic Membranes for Biomedical Applications

The amniotic membrane (AM) is the innermost part of the fetal placenta, which surrounds and protects the fetus. Due to its structural components (stem cells, growth factors, and proteins), AMs display unique biological properties and are a widely available and cost-effective tissue. As a result, AMs have been used for a century as a natural biocompatible dressing for healing corneal and skin wounds. To further increase its properties and expand its applications, advanced hybrid materials based on AMs have recently been developed. One existing approach is to combine the AM with a secondary material to create composite membranes. This review highlights the increasing development of new multilayer composite-based AMs in recent years and focuses on the benefits of additive manufacturing technologies and electrospinning, the most commonly used strategy, in expanding their use for tissue engineering and clinical applications. The use of AMs and multilayer composite-based AMs in the context of nerve regeneration is particularly emphasized and other tissue engineering applications are also discussed. This review highlights that these electrospun multilayered composite membranes were mainly created using decellularized or de-epithelialized AMs, with both synthetic and natural polymers used as secondary materials. Finally, some suggestions are provided to further enhance the biological and mechanical properties of these composite membranes.

Freeze-dried amniotic membrane graft with a spongy layer in bilateral peripheral ulcerative keratitis: a case report

BACKGROUND

Peripheral ulcerative keratitis (PUK) is a group of inflammatory corneal ulcers with stromal thinning and peripheral localization. Amniotic membranes (AM) are used for their anti-inflammatory and healing properties. A freeze-drying process now allows maintaining the AM viable for a long time at room temperature without altering its physical, biological, and morphologic characteristics. The effectiveness of spongy freeze-dried amniotic membrane (FD-AM) graft with multimodal imaging in the management of severe corneal thinning PUK has not been reported.

CASE PRESENTATION

A 67-year-old Caribbean man histologically diagnosed with ulcerative colitis, was referred to our tertiary eye care center for a deep nasal juxtalimbal ulcer of the left eye. He was treated with topical steroids and antibiotics, methylprednisolone pulses, and oral prednisone. Due to continuous stromal thinning with 100 μm of residual corneal thickness, the decision was made to perform surgery. Conjunctival resection, inlay and overlay spongy FD-AM (Visio Amtrix® S, Tissue Bank of France, FR) were performed to preserve globe integrity. Despite tapering off oral steroids, PUK developed in the fellow eye on the 2 months follow-up. Treatment with human monoclonal antibody against tumor necrosis factor-alpha was initiated to control the active underlying inflammation. Six months following surgery, the ulcer was healed and corneal thickness in front of the former ulceration was measured at 525 μm on anterior segment-optical coherence tomography. Confocal microscopy confirmed the integration of the amniotic membrane between the corneal epithelium and the anterior stroma.

CONCLUSION

Transplantation of FD-AM with a spongy layer was associated with restoration of normal corneal thickness in the PUK area. It seems to be a safe, effective, and easily accessible solution for the surgical management of PUK with impending perforation.

Creation of a novel synthetic amniotic fluid for use in fetal therapy with in vitro testing on human amniotic membranes

BACKGROUND

Normal saline or lactated Ringer's solutions are usually infused at the time of fetal interventions; however, the effect of these fluids on the amniotic membranes has never been assessed. Given both the significant differences between the composition of normal saline solution, lactated Ringer's solution, and amniotic fluid and the significant risk of prematurity after fetal interventions, an investigation is warranted.

OBJECTIVE

This study aimed to evaluate the effect of current amnioinfusion fluids on the human amnion compared with a novel synthetic amniotic fluid.

STUDY DESIGN

Amniotic epithelial cells from term placentas were isolated and cultured per protocol. A synthetic amniotic fluid was created with similar electrolyte, pH, albumin, and glucose concentrations to human amniotic fluid, termed "Amnio-well." The cultured human amniotic epithelium was exposed to normal saline solution, lactated Ringer's solution, and Amnio-well. As a control, 1 group of cells remained in culture media. Cells were evaluated for apoptosis and necrosis. A second analysis to examine if cells could be "rescued" was performed, wherein the cells were allowed to remain in the culture media for an additional 48 hours after amnioinfusion. Subsequently, tissue testing with human amniotic membrane explants was evaluated similarly. Immunofluorescent intensity studies were undertaken to evaluate reactive oxygen species-mediated cell damage. Real-time quantitative polymerase chain reaction was used to evaluate gene expression in apoptotic pathways.

RESULTS

With simulated amnioinfusion, 44%, 52%, and 89% of amniotic epithelial cells were alive after exposure to normal saline solution, lactated Ringer's solution, and Amnio-well, respectively, compared with 85% in control (P<.001). After amnioinfusion and attempted cell rescue, 21%, 44%, 94%, and 88% of cells were alive after exposure to normal saline solution, lactated Ringer's solution, Amnio-well, and control, respectively (P<.001). In simulated amnioinfusion with full-thickness tissue explants, 68%, 80%, 93%, and 96% of cells were viable in normal saline solution, lactated Ringer's solution, Amnio-well, and control, respectively (P<.001). In culture, reactive oxygen species production was higher in normal saline solution, lactated Ringer's solution, and Amnio-well than in control (4.9-, 6.6-, and 1.8-fold higher, respectively, P<.001); however, this could be mitigated in Amnio-well by adding ulin-A-statin and ascorbic acid. Gene expression data revealed abnormal signaling in the p21 and BCL2/BAX pathways with normal saline solution compared with control (P=.006 and P=.041); changes were not seen with Amnio-well.

CONCLUSION

In vitro, normal saline and lactated Ringer's solutions caused increased amniotic membrane reactive oxygen species and cell death. The use of a novel fluid similar to human amniotic fluid led to the normalization of cellular signaling and less cell death.

Cx43 regulates mechanotransduction mechanisms in human preterm amniotic membrane defects

OBJECTIVE

The effects of mechanical stimulation in preterm amniotic membrane (AM) defects were explored.

METHODS

Preterm AM was collected from women undergoing planned preterm caesarean section (CS) due to fetal growth restriction or emergency CS after spontaneous preterm prelabour rupture of the membranes (sPPROM). AM explants near the cervix or placenta were subjected to trauma and/or mechanical stimulation with the Cx43 antisense. Markers for nuclear morphology (DAPI), myofibroblasts (αSMA), migration (Cx43), inflammation (PGE2 ) and repair (collagen, elastin and transforming growth factor β [TGFβ1 ]) were examined by confocal microscopy, second harmonic generation, qPCR and biochemical assays.

RESULTS

In preterm AM defects, myofibroblast nuclei were highly deformed and contractile and expressed αSMA and Cx43. Mechanical stimulation increased collagen fibre polarisation and the effects on matrix markers were dependent on tissue region, disease state, gestational age and the number of fetuses. PGE2 levels were broadly similar but reduced after co-treatment with Cx43 antisense in late sPPROM AM defects. TGFβ1 and Cx43 gene expression were significantly increased after trauma and mechanical stimulation but this response dependent on gestational age.

CONCLUSION

Mechanical stimulation affects Cx43 signalling and cell/collagen mechanics in preterm AM defects. Establishing how Cx43 regulates mechanosignalling could be an approach to repair tissue integrity after trauma.

Periodontal Regeneration with Amnion-Chorion Membrane on Root Surface: A Retrospective Case Series

This retrospective case series investigated the clinical and radiographic outcomes in 19 intrabony defects treated with periodontal regenerative therapy utilizing a combined approach. Placing an amnion-chorion membrane (ACM) as a biologic modifier on the root surface of the periodontally diseased tooth, combined with bone substitutes and an additional ACM as a barrier membrane, the treated sites were examined 8 to 24 months after the therapy. The preoperative (baseline) mean probing pocket depth (PPD) was 7.21 ± 1.08 mm, and the mean clinical attachment level (CAL) was 7.68 ± 1.49 mm. A mean PPD reduction of 4.05 ± 1.22 mm, CAL gain of 3.68 ± 1.34 mm, and 73.91% ± 22.02% of bone fill were recorded postoperatively. Without any adverse events, root-surface application of ACM as a biologic material in periodontal regenerative therapy could be a safe and cost-effective approach.

Gelatin nanofiber-reinforced decellularized amniotic membrane promotes axon regeneration and functional recovery in the surgical treatment of peripheral nerve injury

Effective recovery of peripheral nerve injury (PNI) after surgical treatment relies on promoting axon regeneration and minimizing the fibrotic response. Decellularized amniotic membrane (dAM) has unique features as a natural matrix for promoting PNI repair due to its pro-regenerative extracellular matrix (ECM) structure and anti-inflammatory properties. However, the fragile nature and rapid degradation rate of dAM limit its widespread use in PNI surgery. Here we report an engineered composite membrane for PNI repair by combining dAM with gelatin (Gel) nanofiber membrane to construct a Gel nanofiber-dAM composite membrane (Gel-dAM) through interfacial bonding. The Gel-dAM showed enhanced mechanical properties and reduced degradation rate, while retaining maximal bioactivity and biocompatibility of dAM. These factors led to improved axon regeneration, reduced fibrotic response, and better functional recovery in PNI repair. As a fully natural materials-derived off-the-shelf matrix, Gel-dAM exhibits superior clinical translational potential for the surgical treatment of PNI.

Clinical outcomes, time span for healing of various ocular surface disorders with amniotic membrane: A prospective, an Indian study

Purpose

To study the clinical outcomes, time span of healing of various ocular surface disorders with amniotic membrane graft.

Methods

A total of 41 patients, presenting to cornea clinic were included in the study and divided into five groups depending on the type of diagnosis: Group 1, with either >2 weeks of Persistent epithelial defect following cataract/retinal/glaucoma surgeries or Shield ulcers, Group 2 with >4 weeks of Non healing corneal ulcers, Group 3 with chemical injuries, Group 4 with Epithelial defects following keratoplasty, and Group 5 is the miscellaneous group.

Results

The mean age of the study subjects was 50.0 years. Overall mean duration between clinical presentation and AMT was 23.59 (30.7) days, a median 16 days (IQR; 2-26 days). Failure rate was high in Group 5 (n = 3: 30.0%) and Group 2 (n = 3: 27.3%). Time taken for epithelial closure was slower in groups 1 and 5 patients. The average time taken for reabsorption of AMG was 14.98 days. The complications included repeat AMG was in four eyes (9.75%), and graft displacement was noted in four eyes (9.75%) required resuturing, three eyes required TPK (7.31%), and one eye underwent evisceration (2.43%) following severe corneal melt secondary to neurotropic ulcer. The mean log MAR visual acuity improved from 1.52 to 1.26 at the 3 months.

Conclusion

Understanding on timespan for healing of ocular surface disorders with AMG is needed to assess the prognosis of the disease, preoperative counselling for repeat procedures, and the compliance with regard to follow up.

Tracheal regeneration with acellular human amniotic membrane and 15-deoxy-∆12,14prostaglandinj2 nanoparticles in a rabbit model

The treatment of tracheal pathologies remains challenging.Nanotechnology allows adding substances to decellularized human amniotic membrane (DHAM), such as 15-Deoxy-∆12,14ProstaglandinJ2 nanoparticles (15D-PGJ2-NC).This study performed a tracheotomy in rabbits randomized into three groups.The tissue repair process was evaluated when treated with DHAM associated or not with 15D-PGJ2-NC.The average of the area in the control group was 54.76% smaller than DHAM group and 41.98% smaller than DHAM + 15D-PGJ2-NC group (p=0.004 for both).The DHAM + 15D-PGJ2-NC group had significantly more immature cartilage (p=0.015).DHAM impregnated with 15D-PGJ2-NC could provide support for the healing of the tracheal defect and may prevent reduction of its lumen.

Amniotic Membrane and Its Derivatives: Novel Therapeutic Modalities in Liver Disorders

The liver is a vital organ responsible for metabolic and digestive functions, protein synthesis, detoxification, and numerous other necessary functions. Various acute, chronic, and neoplastic disorders affect the liver and hamper its biological functions. Most of the untreated liver diseases lead to inflammation and fibrosis which develop into cirrhosis. The human amniotic membrane (hAM), the innermost layer of the fetal placenta, is composed of multiple layers that include growth-factor rich basement membrane, epithelial and mesenchymal stromal cell layers. hAM possesses distinct beneficial anti-fibrotic, anti-inflammatory and pro-regenerative properties via the secretion of multiple potent trophic factors and/or direct differentiation into hepatic cells which place hAM-based therapies as potential therapeutic strategies for the treatment of chronic liver diseases. Decellularized hAM is also an ideal scaffold for liver tissue engineering as this biocompatible niche provides an excellent milieu for cell proliferation and hepatocytic differentiation. Therefore, the current review discusses the therapeutic potential of hAM and its derivatives in providing therapeutic solutions for liver pathologies including acute liver failure, metabolic disorders, liver fibrosis as well as its application in liver tissue engineering.

Amniotic Membrane-Derived Stromal Cells Release Extracellular Vesicles That Favor Regeneration of Dystrophic Skeletal Muscles

Duchenne muscular dystrophy (DMD) is a muscle disease caused by mutations in the dystrophin gene characterized by myofiber fragility and progressive muscle degeneration. The genetic defect results in a reduced number of self-renewing muscle stem cells (MuSCs) and an impairment of their activation and differentiation, which lead to the exhaustion of skeletal muscle regeneration potential and muscle replacement by fibrotic and fatty tissue. In this study, we focused on an unexplored strategy to improve MuSC function and to preserve their niche based on the regenerative properties of mesenchymal stromal cells from the amniotic membrane (hAMSCs), that are multipotent cells recognized to have a role in tissue repair in different disease models. We demonstrate that the hAMSC secretome (CM hAMSC) and extracellular vesicles (EVs) isolated thereof directly stimulate the in vitro proliferation and differentiation of human myoblasts and mouse MuSC from dystrophic muscles. Furthermore, we demonstrate that hAMSC secreted factors modulate the muscle stem cell niche in dystrophic-mdx-mice. Interestingly, local injection of EV hAMSC in mdx muscles correlated with an increase in the number of activated Pax7+/Ki67+ MuSCs and in new fiber formation. EV hAMSCs also significantly reduced muscle collagen deposition, thus counteracting fibrosis and MuSCs exhaustion, two hallmarks of DMD. Herein for the first time we demonstrate that CM hAMSC and EVs derived thereof promote muscle regeneration by supporting proliferation and differentiation of resident muscle stem cells. These results pave the way for the development of a novel treatment to counteract DMD progression by reducing fibrosis and enhancing myogenesis in dystrophic muscles.

Positive effect of acellular amniotic membrane dressing with immobilized growth factors in skin wound healing

The human amniotic membrane dressing has been shown to accelerate the wound healing process in the clinic. In this study, heparin was conjugated to a human Acellular Amniotic Membrane (hAAM) to provide affinity binding sites for immobilizing growth factors. To study the acceleration of the wound healing process, we bound epidermal growth factor and fibroblast growth factor 1 to heparinized hAAMs (GF-Hep-hAAMs). The heparinized hAAMs (Hep-hAAMs) were characterized by toluidine blue staining and infrared spectroscopy. The quality control of hAAM was performed by hematoxylin staining, swelling capacity test and biomechanical evaluation. The cytotoxicity, adhesion, and migration in vitro assays of GF-Hep-hAAMs on L-929 fibroblast cells were also studied by MTT assay, scanning electron microscopy, and scratch assay, respectively. Finally, in vivo skin wound healing study was performed to investigate the wound closure rate, re-epithelization, collagen deposition, and formation of new blood vessels. The results showed that GF-Hep-hAAMs enhance the rate of wound closure and epidermal regeneration in BALB/c mice. In conclusion, GF-Hep-hAAMs could accelerate the wound healing process, significantly in the first week.

Preventive Effects of Exosome-Rich Conditioned Medium From Amniotic Membrane-Derived Mesenchymal Stem Cells for Diabetic Retinopathy in Rats

Purpose

Diabetic retinopathy (DR) is an important disease that causes vision loss in many diabetic patients. Stem cell therapy has been attempted for treatment of this disease; however, it has some limitations. This study aimed to evaluate the preventive efficacy of exosome-rich conditioned medium (ERCM) derived from amniotic membrane stem cells for DR in rats.

Methods

Twenty-eight 8-week-old male Sprague-Dawley rats were divided into three groups: group 1, normal control (Con) group; group 2, diabetes mellitus (DM) group; and group 3, DM with ERCM-treated (DM-ERCM) group. DM was induced by intraperitoneal injection of streptozotocin. The DM-ERCM group received ERCM containing 1.2 × 10⁹ exosomes into subconjunctival a total of four times every 2 weeks.

Results

On electroretinogram, the DM-ERCM group had significantly higher b-wave and flicker amplitudes than those in the DM group. In fundoscopy, retinal vascular attenuation was found in both the DM and DM-ERCM groups; however, was more severe in the DM group. On histology, the ganglion cell and nerve fiber layer rates of the total retinal layer significantly increased in the DM group compared with the Con group, whereas the DM-ERCM group showed no significant difference compared with the Con group. Cataracts progressed significantly more in the DM group than that in the DM-ERCM group and there was no uveitis in the DM-ERCM group.

Conclusions

Subconjunctival ERCM delayed the progression of DR and cataracts and significantly reduced the incidence of uveitis.

Translational Relevance

Our study shows the clinical potential of minimally invasive exosome-rich conditioned medium treatment to prevent diabetic retinopathy.

Fabrication and characterization of a novel injectable human amniotic membrane hydrogel for dentin-pulp complex regeneration

OBJECTIVE

Injectable biomaterials that can completely fill the root canals and provide an appropriate environment will have potential application for pulp regeneration in endodontics. This study aimed to fabricate and characterize a novel injectable human amniotic membrane (HAM) hydrogel scaffold crosslinked with genipin, enabling the proliferation of Dental Pulp Stem Cells (DPSCs) and optimizing pulp regeneration.

METHODS

HAM extracellular matrix (ECM) hydrogels (15, 22.5, and 30 mg/ml) crosslinked with different genipin concentrations (0, 0.1, 0.5, 1, 5, and 10 mM) were evaluated for mechanical properties, tooth discoloration, cell viability, and proliferation of DPSCs. The hydrogels were subcutaneously injected in rats to assess their immunogenicity. The hydrogels were applied in a root canal model and subcutaneously implanted in rats to determine their regenerative potential for eight weeks, and histological and immunostaining analyses were performed.

RESULTS

Hydrogels crosslinked with low genipin concentration demonstrated low tooth discoloration, but 0.1 mM genipin crosslinked hydrogels were excluded due to their unfavourable mechanical properties. The degradation ratio was lower in hydrogels crosslinked with 0.5 mM genipin. The 30 mg/ml-0.5 mM crosslinked hydrogel exhibited a microporous structure, and the modulus of elasticity was 1200 PA. In vitro, cell culture showed maximum viability and proliferation in 30 mg/ml-0.5 mM crosslinked hydrogel. All groups elicited minimum immunological responses, and highly vascularized pulp-like tissue was formed in human tooth roots in both groups with/without DPSCs.

SIGNIFICANCE

Genipin crosslinking improved the biodegradability of injectable HAM hydrogels and conferred higher biocompatibility. Hydrogels encapsulated with DPSCs can support stem cell viability and proliferation. In addition, highly vascularized pulp-like tissue formation by this biomaterial displayed potential for pulp regeneration.

THE LONG-TERM FOLLOW-UP OF AUTOLOGOUS BLOOD CLOT-ASSISTED LYOPHILIZED HUMAN AMNIOTIC MEMBRANE COVERING TREATMENT UNCLOSED MACULAR HOLE

PURPOSE

The objectives were to assess the long-term morphologic and functional outcome of eyes with unclosed macular hole (MH) in which the internal limiting membrane has been peeled in previous vitrectomy with autologous blood clot-assisted lyophilized human amniotic membrane (LhAM) graft covering.

METHODS

Twelve eyes with MH unclosed in previous surgery were selected and studied. Autologous blood clot-assisted LhAM graft was used to cover the MH in vitrectomy. The main clinical outcomes including best-corrected visual acuity, closure of MH, and the outcome of LhAM graft were recorded.

RESULTS

The mean minimum diameter of the MH was 641.7 ± 245.9 µ m and the mean axial length was 27.3 ± 3.50 mm. The LhAM graft was maintained in the former position and all the MH closed in 10 eyes, whereas the graft slipped and the MH unclosed in two eyes. The MH closure rate was 83.3% and the mean best-corrected visual acuity improved significantly from 1.47 ± 0.58 logMAR (Snellen 20/590) preoperatively to 1.17 ± 0.60 logMAR (Snellen 20/296) postoperatively. During 18 to 36 months follow-up, LhAM grafts were attached to the retinal surface in nine eyes, detached from the retinal surface in one eye, dislocated from the fovea in one eye, and inserted into the retina in one eye; and macular atrophy occurred in one eye.

CONCLUSION

Autologous blood clot-assisted LhAM graft covering provided a simple and effective treatment option for unclosed MH and reduce surgical trauma. Although the graft remained on the macular surface for a long time, it did not affect the recovery of MH and postoperative vision.