Modification of Decellularized Lyophilized Amniotic Membrane for Biomedicine

Amniotic membrane used as a scaffold in the creation of a tissue-engineered complex for the restoration of the anterior layers of the cornea, and as a therapeutic coating is extremely attractive in that the biological substrate made from it is transparent and bioresorbable, which allows monitoring the state of the pathological focus. At the same time, the biomaterial used for therapeutic effects in corneal pathology should specifically react with tissues, since the cornea is an avascular tissue. Consequently, as a result of the therapeutic effect of the biopolymer, there should be no newly formed vessels either on the surface or in the thickness of the cornea, but at the same time proliferation should be activated and a specific epithelial cover should be formed. On the contrary, in the process of skin and bone regeneration, stimulation of angiogenesis is important. Native amniotic membrane has a set of biologically active substances that are preserved to some extent during preservation. However, native biomaterial is not currently used due to the risk of infecting recipients. Biomaterial stored with preservation of the viability of cellular structures and with a violation of vitality is used. The most common cryopreservation technique undoubtedly allows preserving both the cellular structures and the anatomical integrity of the amniotic membrane, thus retaining biologically active substances. According to researchers, cryopreserved amniotic membrane prevents the formation of new vessels in the implantation zone. However, some researchers who prefer to use lyophilized decellularized biomaterials express their doubt regarding the preservation of biologically active properties even in the amniotic membrane without viable cellular structures and consider it necessary to carry out further studies. Taking into account the experience of the Samara Tissue Bank in developing methods for lyophilization of biological tissues and the widespread use of decellularized matrices and implying the use of physical methods of decellularization and a special mode of sublimation drying, we have developed a method for processing and lyophilization of amniotic membrane. The aim of the given research was to study the preservation of biologically active substances and morphological assessment of efficiency in decellularized lyophilized amniotic membrane.