Human Amniotic Membrane–Derived Biomaterials for Soft Tissue Engineering: Development of 3D-Bioprintable Scaffolds

Abstract

Introduction: Breast reconstruction after mastectomy illustrates the limitations of current soft tissue repair strategies, which remain associated with complications and limited impact on recurrence risk. More broadly, soft tissue regeneration requires biomaterials that combine structural support with bioactivity. Human amniotic membrane (hAM) has been applied in skin, corneal, and urogenital repair and exhibits antitumor, antifibrotic, anti-inflammatory, and immunomodulatory properties.

 Aim: The aim of this research is to develop a 3D-bioprintable scaffold from hAM homogenate (hAM-h) that preserves bioactive properties and supports soft tissue engineering, using post-mastectomy breast reconstruction as a model application.

 Materials and Methods: hAM was isolated from placentas of healthy donors, homogenized, and analyzed for cytokine profile, extracellular matrix content, and rheological behavior using a tensiometer, a viscometer, and a zetasizer. Bioactivity was assessed on adipose-derived mesenchymal stem cells (ATMSCs). Hydrogel formulations were optimized using alginates of different viscosities and concentrations, varying extrusion printing and crosslinking parameters. Optimized alginates were then mixed with hAM-h to form printable bioinks for extrusion-based bioprinting. Printed scaffolds were crosslinked with CaCl₂, characterized mechanically and for swelling, and tested for ATMSC attachment.

 Results: hAM-h contained high levels of growth factors, cytokines, collagens I/IV, and MMPs. Samples showed stable negative surface charge (< –30 mV), heterogeneous particle distribution (~192 nm, PDI > 0.5), and consistent rheological profiles (density, surface tension, viscosity). hAM-h did not impair ATMSC viability in the 2D system and supported their attachment to 3D constructs. Mechanical testing revealed higher compressive resistance and weight retention in high-viscosity alginate/hAM-h scaffolds compared with low-viscosity formulations.

 Conclusion: These findings demonstrate the feasibility of hAM-h/alginate bioinks for engineering stable, bioactive scaffolds that preserve the bioactive properties of hAM-h. The results highlight their potential for soft tissue engineering, with post-mastectomy breast reconstruction as a clinically relevant application.