Abstract: The amniotic fluidderived stem cells (AFSC) possess considerable advantageous characteristics including high proliferation potential, easy availability, low immunogenicity and oncogenicity，and accordance with medical ethnics. Moreover, they do not require the sacrifice of human embryos for their isolation and the cells can differentiate into all three kinds of germs. Accordingly，they initiate a new and very promising field in stem cell research and they will be a potential source of stem cells for therapies related to regeneration medicine of cardiovascular diseases. The research about the AFSC utilization in cardiovascular diseases is just started. Though there were some exciting breakthroughs, there still remain many challenges. In the article，we will discuss AFSC characteristics, influence of amniotic fluid harvesting time on stem cells, isolation and purification, emphasizing mainly on the potential of AFSC differentiation into cardiovascular cells, current situation and problems in this field.
Objective To review the latest development of amniotic fluid-derived stem cells (AFSCs) in regenerative medicine, and to discuss issues related to the studies in the field of AFSCs. Methods The recent articles about AFSCs were extensively reviewed. The important knowledge of AFSCs was introduced in the field of regenerative medicine, and the basic and clinical researches of AFSCs were summarized and discussed. Results Currently, it is confirmed that AFSCs have a multi-directional differentiation capacity, therefore, they have a wide application prospect in regenerative medicine, anti-tumor, and other fields. Conclusion AFSCs will become one of the ideal seed cells in the field of regenerative medicine with extensive research value because of the advantages of easy amniotic fluid sampling, little maternal and child trauma, no tumorigenesis, and no ethical restrictions.
Objective To investigate the feasibility and effect of human amniotic membrane in prevention of tendon adhension after tendon sheat defect repair. Methods The amniotic membrane in size of 1.5 cm × 1.0 cm was harvested from human placenta which was voluntary donated from maternal after cesarean. Forty healthy male Leghorn chicken (aged 3-6 months) were selected, weighing (1.86 ± 0.04) kg. The model of flexor digitorum profundus tendon and tendon sheath defects was established at the third toe. After repair of the flexor digitorum profundus tendon, the human amniotic membrane was used to repair the tendon sheath defect in the right foot (group A), but tendon sheath defect was not repaired in the left foot (group B) . At 1, 2, 4, and 6 weeks after operation, the gross and histological observations were done; the degree of tendon adhesions was graded according to Tang’s tendon adhesion general observation grading standards; and the biomechanical properties (tendon slip length and total flexion angle) were tested. Results All animals survived after operation and incisions healed. Gross and histological observations showed that the new tendon sheath formed with time passing after operation in groups A and B; new tendon sheath was more maturer and smoother in group A than in group B. The degree of tendon adhesions in group A was significantly less than that in group B (P lt; 0.05) at 1 and 6 weeks after operation. The biomechanical test results showed there was no significant difference in the tendon slip length between 2 groups at 1 and 2 weeks after operation (P gt; 0.05), but the tendon slip length of group A was significantly longer than that of group B at 4 and 6 weeks after operation (P lt; 0.05). The total flexion angle of group A was significantly smaller than that of group B at 1, 2, 4, and 6 weeks after operation (P lt; 0.05). Conclusion It is effective in the prevention of tendon adhesion to use the amniotic membrane for repairing the tendon sheath defect, which is beneficial to recovery of the tendon sliding function.
To review the latest development of amniotic fluid-derived stem cell(AFS) and to predict its future appl ication. Methods The recent articles about AFS were extensively reviewed. The origin, culture, identification, and directional differentiation as well as future appl ication of AFS were summarized and discussed. Results In 1993, AFS were thought to be exist possibly, and it was confirmed in recent years. AFS have some surface markers l ike other stem cells, and has multi-differentiated potential and extensive future appl ication in cell therapy and tissue engineering approaches. Conclusion As a new stem cell, AFS remains to be further researched.
Objective To review the latest development of amniotic membrane andits application. Methods Related literatures on the development of amniotic membrane and its application were extensively reviewed and summarized. Results There were amniotic epithelial cells and many growth factors in the outer layer of amniotic membrane and there were many kinds of collagen in the basement. The special structure promoted the growth of many kinds of cells. It was widely used in ophthalmology. Conclusion As it is easily available, compatible, cheap in price, low in antigenicity, and able to promote the growth of many kinds of cells, with few ethical problems involved, amniotic membrane will be more and more widely applied.
Objective To compare the effects of the denudedfreeze-dried-amniotic-membrane and the denuded freeze-dried bovine corneal stroma when they were explanted to repair the corneal defect of rabbits. Methods The amnia from healthy human placentae were prepared with the method reported by LUO Jingcong, which were freeze-dried and sterilized. The bovine cornea was also denuded by typsin, rinsed, freeze-dried, and sterilized. Twenty Japan rabbits weredivided into group A(the amniontic group) and group B(the bovine-corneal-stroma group) at random. The defect was made, which was 7.5 mm in diameter and 1/3 ofthe thickness of the cornea, and the two kinds of materials were explanted to repair the defect. The vascularization and the changes of the operated eye were observed. The samples were taken at 2, 4 and 8 weeks for histologicalexamination. Results The explanted materials were not melted or excluded. There were visible neovessels in both groups, yet there was no significant difference between them. According to the histological observation, there was severe inflammation in both groups 2 weeks after operation, the fibroblasts were proliferated, and the collagen fibers were disorganized; however,the reactions became milder from 4 weeks after operations,andthe neovessles could be seen in groups A and B; at 8 weeks, the collagen fibers were more organized in groups A and B; however,there was still a small area of disorganized fibers left. Conclusion The two materials can lead to rejection to some extent, and so they need to be improved.
Objective To evaluate the clinical efficiency of fresh amniotic membrane transplantation in treatment of stenosis of conjunctival sac. MethodsThirty cases (30 eyes) of stenosis of conjunctival sac were treated with fresh amniotic membrane transplantation. Amniotic membrane was obtained under sterile conditions after elective cesarean delivery. The woman’s serum was negative for HBsAg, syphilis, and human immunodeficiency virus. The placenta was first washedfree of blood clots with sterile saline. Under sterile conditions, the inner amniotic membrane was separated from the chorion by blunt dissection, and was cleaned of blood with the sterile saline again. The membrane was then flattened onto a surgidrape adhesive paper with the epithelium surface up. The paper with the adherent amniotic membrane was then cut into 5 cm×8 cm pieces, and then rinsed in solution containing 4×106 U/L of gentamycin and stored at 4℃. It could bestored for 12 hours after preparation. The-adhesiotomy was performed firstly. The separation between the conjunctiva and scar tissue should be complete and wide enough to reach to the orbital margin. The adhesiectomy was taken secondly. The scar tissues were removed completely. The fresh amniotic membrane was flattened onto the conjunctival defect with epithelium side up. The fresh amniotic membranewas 10 mm more than the conjunctival defect by trimming off the excess portion.This fashioned membrane was then secured to surrounding conjunctival edge with continuous 7-0 nylon sutures. The necessary mattress suture of inferior conjunctival fornix via skin next to the inferior orbital margin was performed simultaneously. The retrobular implantation of the an artificial globe made of hydroxyapatite was performed on some patients with sunken eye. Correction of traumatic ptosis was performed on a few patients.Results The operation ofreconstruction of partial conjunctival sac for 30 cases was successful. All amniotic membrane grafts were alive. The cosmetic result was complete favorable. The infection and contracture of the graft, immunologic rejection and amniotic lysis were not observedin all cases during the follow-up period of 13-18 months.Conclusion Fresh amniotic membrane transplantation can be used in reconstruction of the partial conjunctival sac effectively and can be popularized in thelocal hospital in China because the amniotic membrane can be obtained easily.
OBJECTIVE: To evaluate the therapeutic effect of amniotic membrane transplantation(AMT) for ocular burn. METHODS: Twenty patients with ocular burn(28 eyes) were treated with amniotic membrane transplantation. Of them, there were 6 cases of severe alkali burn(10 eyes), 8 cases of severe acid burn(10 eyes), and 6 cases of thermal burn(8 eyes). RESULTS: In 28 eyes, ocular inflammation was controlled after 3-7 days of surgery; no continued dissolution, perforation and iris atrophy were found. There were corneal transparency in 16 eyes, keratoleukoma in 4 eyes, and total corneal opacity in 8 eyes. All eyeballs were saved and had stable ocular surface. There was no allograft immune rejection and secondary infection. CONCLUSION: Amnitic membrane transplantation can relieve the inflammatory reaction, reduce the growth of blood vessel and restrain the proliferation of fibrous tissue. It is an effect surgical method for ocular burn in reconstruction of ocular surface and salvage of eyeball.
Objective To investigate the feasibility of human amniotic membrane-living skin equivalent (AM-LSE) in repairing the skin defect. Methods A 5-year-old boy with giant nevus at neck, shoulder, and back was admitted in July 2016. Normal skin tissue of the patient was harvested and keratinocytes and dermal fibroblasts were separated and expanded in vitro. Human AM was donated from a normal delivery and de-epithelialized for constructing an LSE as a matrix. Keratinocytes were seeded on the epithelial side of the AM which was previously seeded with fibroblasts on the stromal side and then the complex was lifted for air-liquid surface cultivation for 10 days and observed under naked eyes and sampled for histological study. The nevus was excised to deep fascia and the skin defect in size of 20 cm×15 cm was covered with artificial skin of collagen sponge for 2 weeks to enhance granulation tissue formation, and then the AM-LSE grafts of stamp size were grafted on. The dressing was changed until the wound healed. Results After 10 days of air-liquid surface cultivation, the AM-LSE developed a multilayered and differentiated epidermis with the fibroblasts-populated amnion as the dermal matrix. The LSE stamps survived and expanded to cover the whole wound. The grafted area showed normal skin color and soft contexture at 6 months after operation, and histological study showed well developed epidermis with compactly aligned basal cells, stratified and well differentiated squamous, granular layers and stratum corneum and well vascularized dermal compartment without inflammatory cells infiltration. Conclusion The cultivated AM-LSE with autologous cells can repair skin defect and survive for a long term without rejection.
Objective To study the clinical significance of the microorganism culture result of amniotic fluid in cesarean section in the treatment of anti-infection after operation. Methods From August 2016 to May 2017 in Women’s and Children’s Hospital of Sichuan Province, 502 amniotic fluid samples were collected in cesarean section to carry out bacteria culture. The correlations between the amniotic fluid culture result and the preoperative and intraoperative risk factors and the correlations between postoperative infection and the preoperative and intraoperative risk factors were analyzed. Results In the 502 amniotic fluid samples, there were 131 samples culture-positive. The microbiological culture results of amniotic fluid were statistically different between the puerperae with gestational age<37 weeks and the ones with gestational age≥37 weeks (P=0.001). Postoperative infection occurred in 6 puerperae, in whom the amniotic fluid culture results were positive in 3 puerperae. There was no statistical difference in the occurrence of postoperative infection between the puerperae with amniotic fluid culture-positive results and the ones with negative results (P=0.382). The occurrence of postoperative infection was associated with preoperative infections, gestational age, using time of antimicrobial, and preoperative rupture of membranes (P<0.05). Conclusions The contamination rate of amniotic fluid specimen was high, which was of low reference value to anti-infection treatment after operation. When an extension of anti-infection treatment be carried out after cesarean section, suitable specimens should be selected according to the infection site.