Search

The fetal membranes provide a supportive environment for the growing embryo and later fetus. Due to their versatile properties, the use of fetal membranes in tissue engineering and regenerative medicine is increasing in recent years. Moreover, as microbial infections present a crucial complication in various treatments, their antimicrobial properties are gaining more attention. The antimicrobial peptides (AMPs) are secreted by cells from various perinatal derivatives, including human amnio-chorionic membrane (hACM), human amniotic membrane (hAM), and human chorionic membrane (hCM). By exhibiting antibacterial, antifungal, antiviral, and antiprotozoal activities and immunomodulatory activities, they contribute to ensuring a healthy pregnancy and preventing complications. Several research groups investigated the antimicrobial properties of hACM, hAM, and hCM and their derivatives. These studies advanced basic knowledge of antimicrobial properties of perinatal derivatives and also provided an important insight into the potential of utilizing their antimicrobial properties in a clinical setting. After surveying the studies presenting assays on antimicrobial activity of hACM, hAM, and hCM, we identified several considerations to be taken into account when planning future studies and eventual translation of fetal membranes and their derivatives as antimicrobial agents from bench to bedside. Namely, (1) the standardization of hACM, hAM, and hCM preparation to guarantee rigorous antimicrobial activity, (2) standardization of the antimicrobial susceptibility testing methods to enable comparison of results between various studies, (3) investigation of the antimicrobial properties of fetal membranes and their derivatives in the in vivo setting, and (4) designation of donor criteria that enable the optimal donor selection. By taking these considerations into account, future studies will provide crucial information that will enable reaching the optimal treatment outcomes using the fetal membranes and their derivatives as antimicrobial agents.

Urinary tract infections (UTIs) represent a serious global health issue, especially due to emerging multidrug-resistant UTI-causing bacteria. Recently, we showed that the human amniotic membrane (hAM) could be a candidate for treatments and prevention of UPEC and Staphylococcus aureus infections. However, its role against multidrug-resistant bacteria, namely methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamases (ESBL) producing Escherichia coli and Klebsiella pneumoniae, vancomycin-resistant Enterococci (VRE), carbapenem-resistant Acinetobacter baumannii, and Pseudomonas aeruginosa has not yet been thoroughly explored. Here, we demonstrate for the first time that the hAM homogenate had antibacterial activity against 7 out of 11 tested multidrug-resistant strains, the greatest effect was on MRSA. Using novel approaches, its activity against MRSA was further evaluated in a complex microenvironment of normal and cancerous urinary bladder urothelia. Even short-term incubation in hAM homogenate significantly decreased the number of bacteria in MRSA-infected urothelial models, while it did not affect the viability, number, and ultrastructure of urothelial cells. The hAM patches had no antibacterial activity against any of the tested strains, which further exposes the importance of the hAM preparation. Our study substantially contributes to basic knowledge on the antibacterial activity of hAM and reveals its potential to be used as an antibacterial agent against multidrug-resistant bacteria.

Bolezni sečil zaradi staranja prebivalstva predstavljajo vedno večji izziv. Z namenom iskanja novih terapevtskih pristopov, smo v doktorski disertaciji analizirali učinek pripravkov iz humane amnijske membrane (AM) na rakave urotelijske celice ter uropatogene bakterije. Z različnimi celično-biološkimi, molekularnimi in mikrobiološkimi pristopi smo analizirali učinek nosilcev iz AM, homogenata AM in celic AM na celice T24, ki izvirajo iz humane mišično invazivne urotelijske neoplazije. Ugotovili smo, da 1) nosilci iz AM zavirajo proliferacijo in zmanjšajo invazivni potencial celic T24 ter prispevajo k njihovi mezenhimsko-epitelijski transformaciji, 2) homogenat AM zavira proliferacijo in povzroča luščenje celic T24 ter preprečuje njihovo pritrjanje na podlago in 3) da celice AM zavirajo proliferacijo celic T24. Protimikrobni učinek pripravkov iz AM smo testirali na 25-ih sevih uropatogenih bakterijskih vrst. Dokazali smo, da koščki sveže (svAM) in krioshranjene AM (kAM) nimajo protimikrobnega učinka, medtem ko homogenati svAM in kAM povzročijo cono protimikrobnega učinka pri 16 od 25 testiranih sevov uropatogenih bakterijskih vrst. Protimikrobno delovanje homogenata kAM smo dokazali tudi na z bakterijami okuženih modelih normalnega in rakavo spremenjenega urotelija in vitro. Način priprave ter shranjevanja AM vpliva na obseg njenega protimikrobnega učinka. Ugotovitve, da pripravki iz AM delujejo zaviralno na rakave urotelijske celice in izbrane uropatogene seve uropatogenih bakterijskih vrst, pomembno prispevajo k razumevanju delovanja AM ter predstavljajo izhodišče za nadaljnje študije, ki bodo vrednotile možnosti uporabe AM v urologiji. The urinary tract diseases pose an increasing challenge due to the aging of population. We aimed to find new therapeutic approaches, thus we analysed the effect of human amniotic membrane-derived (AM) preparations on cancer urothelial cells and uropathogenic bacteria. Using different cell-biological, molecular and microbiological approaches we analysed the effect of AM scaffolds, AM homogenate and AM-derived cells on T24 cells, derived from human muscle-invasive bladder cancer. We demonstrated that 1) AM scaffolds diminish the proliferation and reduce the invasive potential of T24 cells and contribute to their mesenchymal-to-epithelial transformation, 2) AM homogenate diminishes the proliferation and causes detachment of T24 cells and prevents their attachment to the surface and 3) AM-derived cells diminish the proliferation of T24 cells. The antimicrobial effect of AM preparations was tested on 25 strains of uropathogenic bacterial species. We demonstrated that patches of fresh (fAM) and cryopreserved AM (cAM) have no antimicrobial effect, while the fAM and cAM homogenates have antimicrobial effect on 16 out of 25 tested strains of uropathogenic bacterial species. Moreover, cAM homogenate has antimicrobial effect also on bacteria-infected in vitro models of normal and cancerous urothelium. The manner of preparation and storage of AM affects the range of its antimicrobial effect. Findings that AM preparations inhibit cancer urothelial cells and selected strains of uropathogenic bacteria, importantly contribute to to the knowledge of AM activity and serve as a baseline for studies that will evaluate the use of AM in urology.

Amniotic membrane (AM) is the innermost layer of the placenta, surrounding and protecting the embryo. AM is a multilayered tissue composed of amniotic epithelial cells, amniotic mesenchymal stromal cells, basal lamina, and stroma. AM's properties, which are the result of its structural features, render it extremely useful for therapeutic purposes, since it enhances epithelisation, is a substrate for cell growth, decreases fibrosis and tissue neovascularisation and has antimicrobial properties. Due to its mechanical properties, which are mostly a result of the basal lamina's and stroma's extracellular matrix, and different growth factors that it contains, AM is increasingly used as a biological scaffold in regenerative medicine. Regenerative medicine is an interdisciplinary field of research and clinical applications, utilising principles of biological and engineering sciences for the development of viable tissue or organ substitutes. In regenerative medicine, we distinguish between three approaches: 1) engraftment of functional cells (including stem cells) into the damaged or defective tissue; 2) reshaping of the damaged or defective tissue using synthetic or natural materials; and 3) tissue engineering, i.e. the use of scaffolds for the enhancement of the growth of tissue-specific cells and development of new, regenerated tissue. Furthermore, we present the use of AM as a biological scaffold in regenerative medicine in Slovenia.

Background: The primary role of amniotic membrane is to protect the foetus from drying out and to provide a suitable environment for its development. Understanding of the structure and function of amniotic membrane is important in terms of its use in clinical settings, especially in regenerative medicine. This paper describes favourable mechanical and biological properties of amniotic membrane for regenerative medicine uses and emphasizes its anticancer properties. Conclusion: Studies on in vitro as well as on animal models demonstrate that amniotic membrane inhibits the proliferation of cancer cells and induces their apoptosis. It also acts immunoinhibitory, and it inhibits the metabolic activity of cancer cells and angiogenesis. This work provides an overview of the latest knowledge about the anticancer role of amniotic membrane and evaluates the potential of the amniotic membrane use for anticancer therapy and regenerative medicine.