Biological tissues from various anatomical sources have been utilized for tissue transplantation and have developed into an important source of extracellular scaffolding material for regenerative medicine applications. Tissue scaffolds ideally integrate with host tissue and provide a homeostatic environment for cellular infiltration, growth, differentiation, and tissue resolution. The human amniotic membrane is considered an important source of scaffolding material due to its 3D structural architecture and function and as a source of growth factors and cytokines. This tissue source has been widely studied and used in various areas of tissue repair including intraoral reconstruction, corneal repair, tendon repair, microvascular reconstruction, nerve procedures, burns, and chronic wound treatment. The production of amniotic membrane allografts has not been standardized, resulting in a wide array of amniotic membrane products, including single, dual, and tri-layered products, such as amnion, chorion, amnion–chorion, amnion–amnion, and amnion–chorion–amnion allografts. Since these allografts are not processed using the same methods, they do not necessarily produce the same clinical responses. The aim of this review is to highlight the properties of different human allograft membranes, present the different processing and preservation methods, and discuss their use in tissue engineering and regenerative applications.

Human amniotic membrane (hAM), the innermost placental layer, has unique properties that allow for a multitude of clinical applications. It is a common misconception that birth-derived tissue products, such as dual-layered dehydrated amnion–amnion graft (dHAAM), are similar regardless of the manufacturing steps. A commercial dHAAM product, Axolotl Biologix DualGraft™, was assessed for biological and mechanical characteristics. Testing of dHAAM included antimicrobial, cellular biocompatibility, proteomics analysis, suture strength, and tensile, shear, and compressive modulus testing. Results demonstrated that the membrane can be a scaffold for fibroblast growth (cellular biocompatibility), containing an average total of 7678 unique proteins, 82,296 peptides, and 96,808 peptide ion variants that may be antimicrobial. Suture strength results showed an average pull force of 0.2 N per dHAAM sample (equating to a pull strength of 8.5 MPa). Tensile modulus data revealed variation, with wet samples showing 5× lower stiffness than dry samples. The compressive modulus and shear modulus displayed differences between donors (lots). This study emphasizes the need for standardized processing protocols to ensure consistency across dHAAM products and future research to explore comparative analysis with other amniotic membrane products. These findings provide baseline data supporting the potential of amniotic membranes in clinical applications.

Background/Objectives: Amniotic-derived biologics have emerged as powerful modulators of tissue regeneration. This study evaluates the composition and characteristics of a human stem cell-conditioned media (hSCCM) that is a sterile, cell-free, amniotic-derived solution, and the presumed efficacy of hSCCM as an active ingredient in an enriched cosmetic lotion. Methods: Data from preclinical benchtop studies and an exploratory observational assessment were reviewed. First, an investigation of the active ingredient, hSCCM, was completed. Flow cytometry assays were completed for mesenchymal stem cell (MSC) characterization. Cellular proliferation assays were conducted to evaluate concentration response, shelf life, and temperature stability. ELISA and LC-MS/MS were used to specify and detail the proteomics of the hSCCM. Second, the hSCCM-enriched lotion’s cosmetic safety and efficacy were evaluated. Preliminary microbial, stability, and early-stage nonclinical retrospective user evaluation of the hSCCM-enriched lotion was conducted to help characterize the cosmetic and evaluate topical safety and efficacy. Results: Flow cytometry demonstrated alignment with ISCT (International Society for Cell and Gene Therapy) characterization for MSCs. Initial in vitro data demonstrated enhanced proliferative effects at hSCCM concentrations as low as 5% (p-value < 0.0001); no statistically significant trend in proliferative capability in aged samples (p-value = 0.79), and no significant effect on proliferative capability when exposed to acute temperature changes (p-values all above 0.05) were observed. Proteomic characterization showed an enriched amniotic-derived solution. Microbial testing of the enriched lotion demonstrated success with multiple unique preservative formulations. hSCCM-enriched lotion demonstrated stability across acute cold- and heat-stress representative scenarios. An exploratory retrospective observational analysis revealed promising trends. Conclusions: The hSCCM demonstrates topical efficacy across in vitro dermal and follicular assays via proliferative and regenerative mechanisms and protein enrichment. The enriched lotion showed success in early-stage microbial and stability testing and demonstrates positive trends in topical skin outcomes. These findings support their potential translational application in dermatologic and aesthetic usage, and broader integumentary contexts.