Stem Cells: advanced biological architecture, developmental trajectories, and clinical relevance in the maternal–neonatal continuum

Biological Characteristics and Function of Stem Cells

Stem cells constitute a biologically distinct and highly specialized cell population, characterized by an intrinsic capacity for long-term self-renewal and by the ability to generate differentiated cells belonging to various tissues and organs. They represent the core of the processes of development, maintenance, and repair of tissue architecture and constitute the primary mechanism through which the organism governs its biological plasticity.

From embryogenesis through adulthood, stem cells ensure the continuous renewal of tissues by replacing cells that undergo senescence or damage and by activating adaptive and regenerative mechanisms in response to both physiological and pathological conditions.

They perform an essential function as a biological reserve of the organism, responsible for replacing cells that undergo senescence, damage, or programmed cell death. Their principal utility lies in their ability to guarantee continuous tissue renewal, preserving tissue structure and function over time. Under physiological conditions, they participate in normal processes of growth, development, and cellular turnover; under pathological conditions, they contribute to tissue repair and regenerative mechanisms.

From a functional standpoint, stem cells play a central role in maintaining cellular homeostasis and in preserving the structural and functional continuity of tissues with high turnover. In clinical practice, stem cells are used to:

• Restore the hematopoietic system after myeloablative treatments such as chemotherapy or radiotherapy, through hematopoietic stem cell transplantation in the treatment of leukemias, lymphomas, myelomas, and other blood disorders;
• Regenerate damaged or degenerated tissues, promoting the functional reconstitution of compromised cellular compartments such as skin, cartilage, bone, and connective tissues;
• Modulate the immune response, owing to the ability of certain stem cell populations—particularly mesenchymal stem cells—to exert immunoregulatory and anti-inflammatory effects, with potential applications in autoimmune diseases and transplantation;
• Reduce the risk of rejection in allogeneic transplants, especially when perinatal stem  cells are used, as they are characterized by immunological immaturity;
• Support regenerative and personalized medicine strategies, providing a biological foundation for targeted therapies tailored to the genetic and clinical profile of the individual patient.

Stem Cells in Scientific and Experimental Research

Beyond their direct therapeutic use, stem cells play a fundamental role in scientific and experimental research. They are used to study the mechanisms of human development, cellular differentiation, and genetic diseases; to test new drugs and therapies while reducing reliance on animal models and improving the predictive value of clinical outcomes; and to develop in vitro disease models that are useful for understanding the pathophysiology of complex disorders and identifying new therapeutic targets.

Biological Sources and Perinatal Stem Cells

Stem cells can be isolated from different anatomical and functional compartments, each characterized by specific biological properties. Major sources include bone marrow, mobilized peripheral blood, various adult tissues, and, in the perinatal setting, umbilical cord blood, the placenta, and Wharton’s jelly.

Stem cells of perinatal origin are of particular interest due to their favorable biological profile, which combines high proliferative capacity with reduced immunogenicity. This is associated with a lower incidence of immunological complications in allogeneic transplants and a high potential for clinical applications throughout the lifespan.

Collection, Processing, and Cryopreservation Procedures

Following collection, stem cells are transferred to highly specialized facilities and subjected to processing procedures in compliance with Good Manufacturing Practices (GMP). The phases of isolation, controlled expansion, immunophenotypic characterization, and cryopreservation are essential to ensure biological safety, genomic stability, and the preservation of cellular functional integrity. Cryopreservation at ultra-low temperatures allows cell viability to be maintained over extended periods, enabling delayed use over time.

Obstetric Collection and Maternal–Neonatal Safety

In the obstetric setting, the collection of perinatal stem cells takes place immediately after birth, within a limited time window following clamping of the umbilical cord. The procedure does not interfere with the physiology of placental delivery, does not pose additional risks to either the mother or the newborn, and does not alter the initiation of breastfeeding.

For the mother, it represents a safe and non-invasive procedure, as well as an opportunity to participate in a pathway of healthcare solidarity; for the newborn, it constitutes the preservation of a biological resource of high value.

Regulatory and Legal Framework

The regulatory framework governing the use of stem cells is characterized by stringent criteria and a high degree of international harmonization. Major guidelines issued by the World Health Organization, the American Academy of Pediatrics, and European scientific societies recognize umbilical cord blood donation as a practice of high healthcare and social value.

At the European level, stem cells fall under the category of Advanced Therapy Medicinal Products (ATMPs), which are subject to rigorous requirements for quality, safety, and efficacy. In Italy, the National Transplant Center and the National Institute of Health regulate collection, storage, and clinical use activities, ensuring procedural uniformity and patient protection.

Conclusione

From a future perspective, the integration of stem cells with advanced technologies such as tissue engineering, smart biomaterials, and genomic editing opens the way to the possibility of repairing, replacing, or regenerating complex organs and tissues, shaping an increasingly precise, safe, and personalized therapeutic approach.

Stem cells do not represent merely a current therapeutic tool but constitute a strategic biological resource for the medicine of both the present and the future. A rigorously regulated clinical use, grounded in solid scientific evidence and supported by a robust ethical and regulatory framework, makes it possible to fully harness their potential for the benefit of the mother, the newborn, and the entire community.