Tissue engineering for prenatal applications

Infection-induced thrombin production: a potential novel mechanism for preterm premature rupture of membranes (PPROM)

Chapter 2. Morphological and Biochemical Heterogeneity of Amniotic Fluid Cells in Culture

Fetal stem cells represent a promising cell source for heart valve tissue engineering. In particular, amniotic fluid-derived cells (AFDC) have been shown to lead to autologous fetal-like heart valve tissues in vitro for pediatric application. In order to expand the versatility of these cells also for adult application, cryopreserved AFDC were investigated as a potential life-long available cell source for heart valve tissue engineering. Human AFDC were isolated using CD133 magnetic beads, and then differentiated and analyzed. After expansion of CD133- as well as CD133+ cells up to passage 7, a part of the cells was cryopreserved. After four months, the cells were re-cultured and phenotyped by flow cytometry and immunohistochemistry, including expression of CD44, CD105, CD90, CD34, CD31, CD141, eNOS and vWF, and compared to their non-cryopreserved counterparts. The stem cell potential was investigated in differentiation assays. The viability of cryopreserved AFDC for heart valve tissue engineering was assessed by creating heart valve leaflets in vitro. After cryopreservation, amniotic fluid-derived CD133- and CD133+ cells retained their stem cell-like phenotype, expressing mainly CD44, CD90 and CD105. This staining pattern was comparable to that of their non-cryopreserved counterparts. Moreover, CD133- cells demonstrated differentiation potential into osteoblast-like and adipocyte-like cells. CD133+ cells showed characteristics of endothelial-like cells by eNOS, CD141 and beginning vWF expression. When used for the fabrication of heart valve leaflets, cryopreserved CD133- cells produced extracellular matrix elements comparable to their non-cryopreserved counterparts. Moreover, the resulting tissues showed a cellular layered tissue formation covered by functional endothelia. The mechanical properties were similar to those of tissues fabricated from non-cryopreserved cells. The study results suggest that the use of cell bank technology fetal amniotic fluid-derived stem cells might represent a life-long available autologous cell source for heart valve tissue engineering, and also for adult application.

Residual amniotic fluid volume predicts the sealing of preterm prelabor rupture of fetal membranes in the pre- and periviable period

Fetal Tissue

Objective To detect Toll like receptor 2(TLR2) expression in tissues of normal human placenta and fetal membranes.Method Placenta and fetal membranes(5 cases)were collected from women with intact membranes underwent elective cesarean sections at term.Expression and localization of TLR2 was detected by RT-PCR,Westen blot analysis and immol/Lunohistochemistry.Results TLR2 messenger RNA was found in tissues of placenta and fetal membranes.Westen blot analysis with TLR2 antibody also yielded positive results for placenta and fetal membranes with one band site around 50 000.Immol/Lunohistochemical localization of TLR2 showed it to be present at syncytotrophoblast of placenta,cytotrophoblast of chorion and epithelial cell of amnion.Conclusion TLR2 expression in tissues of placenta and fetal membranes suggest that TLR2 may play an important role in the innate immol/Lunity of placenta. Key words: Placenta; Fetal membranes; Trophoblasts; Toll like receptor 2; Pattern recognition receptor; Innate immunity

Introduction: The benefits of fetal surgery are impaired by the high incidence of iatrogenic preterm prelabor rupture of the fetal membranes (iPPROM), for which chorioamniotic separation has been suggested as a potential initiator. Despite the urgent need to prevent iPPROM by sealing the fetoscopic puncture site after intervention, no approach has been clinically translated. Methods: A mussel-inspired biomimetic glue was tested in an ovine fetal membrane (FM) defect model. The gelation time of mussel glue (MG) was first optimized to make it technically compatible with fetal surgery. Then, the biomaterial was loaded in polytetrafluoroethylene-coated nitinol umbrella-shaped receptors and applied on ovine FM defects (N = 10) created with a 10 French trocar. Its sealing performance and tissue response were analyzed 10 days after implantation by amniotic fluid (AF) leakage and histological methods. Results: All ewes and fetuses recovered well after the surgery, and 100% ewe survival and 91% fetal survival were observed at explantation. All implants were tight at explantation, and no AF leakage was observed in any of them. Histological analysis revealed a mild tissue response to the implanted glue. Conclusion: MG showed promising properties for the sealing of FM defects and thereby the prevention of preterm birth. Studies to analyze the long-term tissue response to the sealant should be performed.

The purpose of this research was to evaluate the effect of ultrasound on mass transport across fetal membrane for direct fetal drug delivery and sensing of the amniotic fluid in a noninvasive manner. Post-delivery human fetal membranes (chorioamnion) were used for in vitro experiments, in which the effect of ultrasound on transport across fetal membrane of fluorescent model molecule (250 kDa) was evaluated. Ex vivo experiments were carried out on a whole rat amniotic sac. The model molecule or alpha-fetoprotein was injected into the amniotic sac through the placenta. Transport of these molecules across pre- and post-insonation of the amniotic sac was evaluated. The ultrasound enhancement's mechanism was also assessed. The greatest enhancement in mass transport (43-fold) in vitro was achieved for 5 min of insonation (20 kHz, 4.6 W/cm(2), 5 mm distance). Ex vivo results showed a rapid increase (23-fold) in mass transport of the model molecule and also for alphafetoprotein following 30 s of insonation (20 kHz, 4.6 W/cm(2), 5 mm distance). Mass transport across fetal membranes was enhanced post-insonation both in vitro and ex vivo in a reversible and transient manner. We suggest that exterior (to the amniotic sac) ultrasound-induced cavitation is the main mechanism of action.

Objective To detect aquaporin-8(AQP-8) expression in human oligohydramnios placenta and fetal membranes. Methods From December 2008 to January 2009, placenta and fetal membranes samples were obtained from 6 women with oligohydramnios (study group) and 10 women with normal amniotic fluid volume(control group). All of them met the following conditions: Single birth, full term, not in labor, and without pregnancy complications, fetal distress and fetal malformations. All the 16 cases underwent elective cesarean section in department of Obstetrics and Gynecology, Fuyong Hospital of Shenzhen. Informed consent was obtained from all participants. There had no significant difference in age, pregnancy situations, and pregnancy outcome(P>0.05). Aquaporin-8 expression in the tissue samples was detected by immunohistochemical streptavidin enzyme complex (SABC) method. Results Aquaproin-8 expression was detected in both human oligohydramnios placenta and fetal membranes. Aquaproin-8 expression of control group was significantly lower than that of study group (P<0.05). Conclusion Aquaproin-8 expression has a significant reduction in human oligohydramnios placenta and fetal membranes, and it may play an important role in the maternal-fetal fluid exchange and absorption of membrane channels. Key words: aquaporin-8 (AQP-8); oligohydramnios; immunohistochemical streptavidin enzyme complex method; human placenta, membranes

To investigate the karyotypes of amniotic fluid cells and compare the incidence of chromosomal abnormality as well as to evaluate the clinical significance of abnormal karyotypes. A total of 13 648 pregnant women came to Shanghai Jiai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University to do amniocentesis from September 1998 to November 2010, and 13 795 amniotic fluid specimens were successfully extracted and cultured, thus 13 795 fetuses received karyotype diagnosis. These fetuses were grouped according to different indications. If maternal age was ≥ 35, the fetuses were grouped into the advanced maternal age group (4065); and if maternal serum screening test revealed high-risk of trisomy 18 or trisomy 21, the fetuses were grouped into the high-risk serum screening group (6462); and those with abnormal signs of ultrasound screening were grouped into the abnormal ultrasound signs group (1539); and if either of the parents was with chromosome abnormalities, the fetus was grouped into the paternal/maternal abnormality group (108); whereas the remainder were grouped in other factors group (1621). The amniotic fluid cells were in-situ cultured on coverslips, harvested by conventional G-banded methods, and then analyzed by two doctors. In order to get rapid diagnosis, some pregnant women whose gestational age ≥ 26 weeks accepted fluorescense in situ hybridization (FISH). FISH was done on 78 uncultured amniotic fluid specimens using probes located at chromosome 13, 18, 21, X, Y. Some parents were required to analyze lymphocyte karyotype to help judging the origin of abnormal karyotype. (1) Classification and composition of abnormal karyotypes in each group: a total of 388 abnormal karyotypes were found among 13 795 fetuses, and the abnormal rate was 2.813% (388/13 795). Of the 388 fetuses, aneuploidy was the most common pattern which was up to 59.8% (232/388); autosomal structural abnormality rate was 24.7% (96/388); mosaicism was 12.4% (48/388). Other uncommon abnormal karyotypes included marker chromosome (5/388, 1.3%), sex chromosomal structural abnormality (4/388, 1.0%) and triploid (3/388, 0.8%). Aneuploidy was the most common in most groups except the paternal/maternal abnormality group. There were four cases of rare aneuploid in the advanced maternal age group, the high-risk serum screening group and the abnormal ultrasound signs group respectively. Every type of abnormality could be found in the abnormal ultrasound signs group, and autosomal structural abnormalities were concentrated in paternal/maternal abnormality group. Mosaicism mainly distributed in the high-risk serum screening group, accounting for 20.0% (29/145) of abnormalities in this group. (2) Abnormal types and the incidence: the most common type was trisomy 21 (138/388, 35.6%), followed by autosomal balanced structural rearrangements (80/388, 20.6%), mosaicism (48/388, 12.4%) and trisomy 18 (44/388, 11.3%). Others included non-balanced autosomal structural rearrangements (16/388, 4.1%), 45, X0 (16/388, 4.1%) and 47, XXY (15/388, 3.9%). (3) Lymphocyte karyotype analysis of the couples: parents of 153 fetuses were analyzed to determine the origin of abnormal karyotype. Fifty-eight familial and 95 de novo abnormalities were found. FISH results were the same with G-banding karyotype, and two of these were trisomy 21. Abnormal karyotype composition is different according to different maternal amniocentisis indications. There is a variety of abnormal karyotypes in the second trimester pregnancy, and the risk of fetal malformation is related with the kind of abnormal karyotype.

Porous microspheres have the potential for use as injectable bone fillers to obviate the need for open surgery. Successful bone fillers must be able to support vascularisation since tissue engineering scaffolds often cease functioning soon after implantation due to a failure to vascularise rapidly. Here, we test the angiogenic potential of a tissue engineered bone filler based on a photocurable acrylate-based high internal phase emulsion (HIPE). Highly porous microspheres were fabricated via two processes, which were compared. One was taken forward and investigated for its ability to support human mesenchymal progenitor cells and angiogenesis in a chorioallantoic membrane (CAM) assay. Porous microspheres with either a narrow or broad size distribution were prepared via a T-junction microfluidic device or by a controlled stirred-tank reactor of the HIPE water in oil in water (w/o/w), respectively. Culture of human embryonic stem cell-derived mesenchymal progenitor (hES-MP) cells showed proliferation over 11 days and formation of cell-microsphere aggregates. In-vitro, hES-MP cells were found to migrate into microspheres through their surface pores over time. The presence of osteoblasts, differentiated from the hES-MP cells, was evidenced through the presence of collagen and calcium after 30 days. Microspheres pre-cultured with cells were implanted into CAM for 7 days and compared with control microspheres without pre-cultured cells. The hES-MP seeded microspheres supported greater angiogenesis, as measured by the number of blood vessels and bifurcations, while the empty scaffolds attracted host chick cell ingrowth. This investigation shows that controlled fabrication of porous microspheres has the potential to create an angiogenic, bone filling material for use as a cell delivery vehicle.

Several groups including our own have reported gene delivery to fetal organs by vector administration into the amniotic cavity. Based on these studies we hypothesised that the large surface of the fetal skin may be exploitable for high level production of systemically required gene products to be released into the fetal circulation. We administered E1/E3-deleted adenoviral vectors carrying a bacterial beta-galactosidase gene or the human coagulation factor IX gene into the amniotic cavities of mid- to late-gestation mouse fetuses. The concentrations of human factor IX in the plasma of fetal or new-born mice were determined by ELISA. Reverse transcription PCR was used to identify sites of transgene expression. Application of 5 x 10(8) infectious units of the factor IX gene vector in utero resulted in plasma concentrations of human factor IX of up to 1.2 microg/ml without significant decrease in fetal survival. Transgenic protein was found to be produced in the fetal skin, mucosae and amniotic membranes and was shown to be present for several days after birth of healthy pups. As ultrasound-guided amniocentesis in humans is a well-established diagnostic procedure, delivery of the factor IX gene into the amniotic cavity appears to be a safe route for prenatal treatment of haemophilia B and may prevent haemorrhagic complications such as intracranial bleeding during delivery. Our study allowed for the first time a quantification of the expression of a potentially therapeutic transgene in rodents after prenatal gene delivery. It thus provides a model for the prenatal treatment of haemophilia B, but may also serve as a pathfinder to gene therapy of inheritable skin disorders such as epidermolysis bullosa.

Premature rupture of fetal membrane (PROM) is a complication in pregnancy that is an important problem in obstetrics. Many teory have been explaining that cause of PROM, but the etiology is still unknown. Premature rupture of fetal membrane might be caused by apoptosis. The mechanism of PROM due to the apoptosis might cause the extracellular matrix degradation. The apoptosis is influenced by the signal from extracellular and intracellular protein. The intracellular factor is p53. This factors will cause a fetal membrane damage which induce increasing of caspase-3, so that the increasing of apoptosis in fetal membrane will cause the PROM. The present study is an observational analysis designed as a case-control study. The study was carried out in Dr. Hasan Sadikin Hospital and Central Laboratorium of Medical School of Padjadjaran University. The case group consist of 81 patients of PROM selected based on appropriate acceptance and rejection criteria taken by consecutive sampling. The control group consist of 81 patients with normal pregnancies at the age of ?37- 9,734 U/ml) than the normal pregnancy with p 0,97 U/ml would increased in the incidence of PROM more than thirty times

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, degenerative disorders and many other clinical issues. Currently, patients suffering from diseased and injured organs are treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and new cases of organ failure increase. Scientists in the field of regenerative medicine and tissue engineering are now applying the principles of cell transplantation, material science, and bioengineering to construct biological substitutes that can restore and maintain normal function in diseased and injured tissues. In addition, the stem cell field is a rapidly advancing part of regenerative medicine, and new discoveries in this field create new options for this type of therapy. For example, new types of stem cells, such as amniotic fluid and placental stem cells, that can circumvent the ethical issues associated with embryonic stem cells have been discovered. The process of somatic cell nuclear transfer and the creation of induced pluripotent cells provide still other potential sources of stem cells for cell-based tissue engineering applications. While stem cells are still in the research phase, some therapies arising from tissue engineering endeavors that make use of autologous, adult cells have already entered the clinical setting, indicating that regenerative medicine holds much promise for the future.

Progestin treatment does not affect expression of cytokines, steroid receptors, oxytocin receptor, and cyclooxygenase 2 in fetal membranes and endometrium from pony mares at parturition