Biotensegrity: Its Application to Tissue Function and Dysfunction

September - October 2022

Biotensegrity: Its Application to Tissue Function and Dysfunction

Editorial Summary

Understanding the mechanisms of how structures develop, how they work, how they adapt when exposed to other new or changing environments, and how they interact with one another, is essential as it can help us manage impairment and disease. Nature follows assembly rules with intention and efficiency. A specific architecture called tensegrity is how human beings are constructed from common structural elements. Tensegrity provides a mechanism to harmonically and mechanically couple interconnected structures of different size scales and locations throughout living tissue and cells; within the context of this living system, the term is biotensegrity. This article explores this concept and provides a concise overview of the impact to our clinical practice.

Carl Sagan famously stated, ‘We are made of star stuff.’ Essentially, the materials that form our physical bodies were forged in distant, long-extinguished stars. A beautiful sentiment describing the amazing complexity of the human body. Yet, in all complex machines and organisms, there lies a simplicity in the seeming chaos of form and function. Nature follows assembly rules with intention and efficiency. Patterns emerge in all structures ranging from crystals to viruses to flowers to humans and everything in between. These patterns form systems which guide biological design, organization and function at the micro and macro level. How this all works remains a mystery, however Donald Ingber has put forth a unifying theory; “An astoundingly wide variety of natural systems, including carbon atoms, water molecules, proteins, viruses, cells, tissues and even humans and other living creatures, are constructed using a common form of architecture known as tensegrity. The term refers to a system that stabilizes itself mechanically because of the way in which tensional and compressive forces are distributed and balanced within the structure.”1 Ingber describes how the principles of tensegrity are relevant to every aspect of the human body. “At the macroscopic level, the 206 bones that constitute our skeleton are pulled up against the force of gravity and stabilized in a vertical form by the pull of tensile muscles, tendons, and ligaments… In other words, in the complex tensegrity structure inside every one of us, bones are the compression struts, and muscles, tendons and ligaments are the tension-bearing members. At the other end of the scale, proteins and other key molecules in the body also stabilize themselves through the

principles of tensegrity.”1 Tensegrity provides a mechanism to harmonically and mechanically couple interconnected structures of different size scales and locations throughout living tissues and cells.2-4 When framed within the context of living systems, it is termed biotensegrity.

The question remains as to how this all works? How does this choreography maintain and sustain itself? It has been postulated that mechanical stresses play a role in tissue form and growth. Newer evidence suggests it is an interplay between the physical forces of gravity, compression, pressure, tension, and shear that influence growth and remodeling of all tissues at the cellular level.2 Interestingly, these same forces are often used medically as interventions, yet they may also contribute to cellular and tissue disruption, as seen in integumentary dysfunction. Examples include negative pressure wound therapy (NPWT) as an intervention (applying the principles of macro- and micro-strain to the tissues) and sustained pressure/ tissue deformation leading to pressure injury development. Everything is a carefully orchestrated balance to preserve biological functioning with ease. When balance is disrupted, the result is dis-ease.

As all living things are made of star stuff, all life on Earth evolved from the sea. Thirty million years ago, organisms evolved in water without a large influence of gravity. In fact, underwater, gravity is compensated by buoyancy defined as ‘the upward force exerted by a fluid that opposes the weight of an immersed object.’5 Other forces such as lift and drag become more significant in an aquatic environment as these

Dr Heather Hettrick Professor, Dept of Physical Therapy, Nova Southeastern University Fort Lauderdale FL, United States

flow forces vary in direction and magnitude and can even reach higher values than gravity. Further, the lack of surface tension and viscous forces under immersed conditions are also important in the aqueous environment. Aquatic species counterbalance the force of gravity through the pressure exerted around them and through specialized internal organs (form and function). The swim bladder, for example, is a specialized aquatic organ evolutionarily homologous to the lungs.5 It is an internal gas filled organ with flexible walls that contract or expand according to the ambient pressure to obtain neutral buoyancy and ascend and descend to a large range of depths.5 This demonstrates life adapting to its environment and the physical forces acting upon the environment. Just consider the shape and design of aquatic organisms; they are drastically different that organisms on land as they have adapted to their environment and the forces experienced in that ecosystem (whale compared to elephant).

Gravity is a constant force on Earth. Land animals and organisms (as they emerged from the sea) began to develop adaptive mechanisms to orient themselves to the gravity vector, as the mechanical load on land organisms is ~1000 times larger than in water.5 Life on Earth developed in the presence of, and with the influence of gravity. This is rooted in the evolution of terrestrial life. Even at the cellular level, specialized structures have evolved such as statoliths in plants (cells that sense gravity) and otoliths in hair cells of the inner ear, all to respond directly to the force of gravity.

So, what happens when gravity is removed? The reduction and/ or absence of gravity can have profound effects on the physiological, biochemical, histological, and psychosocial components of the human body, or any organism for that matter. This effects every system of the body macroscopically to microscopically, resulting in transient and

permanent dysregulation and adaptation. This has been evidenced from the time of the Apollo launches beginning in the 1960s, to current research being conducted on the International Space Station (ISS) as well as through private space ventures such as SpaceX, Blue Origin and Virgin Galactic. The environment of space, essentially a vacuum devoid of physical forces, subjects those that venture out of the protective fold of the Earth, to challenges that effect the essence of biotensegrity.

Understanding the mechanisms of how structures develop, how they work, how they adapt when exposed to other new or changes in environments, and how they interact with one another is essential, as it can help us manage impairments and disease. This translational knowledge is exemplified from the lessons learned in space regarding human physiology and dysregulation, all of which are directly translatable to improving human health on terra firma. Incredibly, most bodily systems work in tandem and unison to maintain health and homeostasis, even when challenged. This natural rhythm, however, can be disrupted whether endogenously, exogenously or through iatrogenic impacts. Philosophies of treatment to maintain and restore this rhythm are embodied in therapies such as myofascial release (MFR), craniosacral therapy (CST), yoga and shiatsu, to name a few. MFR is manual pressure and stretching directed to loosen restricted movement, improving pain, mobility, and posture. CST is a gentle hands-on technique that uses touch to examine membranes and movement of the fluids in and around the central nervous system (CNS). Relieving tension in the CNS can help to eliminate pain and boost immunity. In essence, these treatments are designed to rebalance biotensegrity. These interventions and philosophies employ external forces to realign the internal forces of tensegrity (solid and liquid fascia), addressing the body as a whole, integrated system.

“Understanding the mechanisms of how structures develop, how they work, how they adapt when exposed to other new or changes in environments, and how they interact with one another is essential, as it can help us manage impairments and disease.”

Another example is highlighted in integumentary disruption. The skin provides the protective mantel that allows biotensegrity to work harmoniously. As all systems are connected and reliant upon one another, skin disruption can lead to numerous impairments and dysregulation throughout the host.

A video titled ‘Strolling Under the Skin’,11 provides an incredible look at biotensegrity in action viewed from the perspective of tissues, particularly the skin and its related structures.This was created by the French surgeon, Jean-Claude Guimberteau. It is geometry in motion revealing the powerful yet delicate dance of living fractals. The creators of this video, reveal this biological marvel as the multimicrovacuolar collagenic dynamic absorbing system (MCDAS). It shows the true inter-connectedness of the systems and in particular, the VAIL. The VAIL is a concept created by the author of this editorial describing how the venous, arterial, integumentary, and lymphatic systems work in unison. These are not siloed structures or systems, but inter-dependent one on another to maintain nominal function. Dysfunction in one system, can and often results in dysfunction in the other systems. For example, the concept of lymphatic dermopathy describes how disorders of the lymph system, whether systemic (macro-lymphedema) or localized (micro-lymphedema), produce cutaneous regions susceptible to infection, inflammation, and carcinogenesis.6-7 Lymphatic impairments result in skin barrier failure and this partially explains why patients with chronic edematous conditions have a propensity for infections (cellulitis in patients with lymphedema) and hypersensitivity reactions (stasis dermatitis in chronic venous disease).

The structure and function of the skin is remarkable. According to Dr. Guimberteau, the skin is more than just an organ, it is ‘a set of organs which areanatomically, physiologically, culturally, and psychically complex.’ In ‘Strolling Under the Skin’, it describes how touch is the

most fundamental of all the senses. “You can survive without smelling, seeing, or tasting, but not without touching. The skin permanently relays information; it never shuts down, blocks up or sleeps. It has an odor, a texture; it perspires, secretes, eliminates. It exchanges signals with the outside world… thanks to the skin, the body’s surface is as much a machine for communication as a protective barrier. It can change color, texture and shape, and retains the vestige of aggression such as sunburn, scars, and disease… through the hairs on its surface, you can see pseudo-geometric structures separated by strength lines allowing movement in all dimensions of space. These triangular pyramidal structures move in relation to each other…the skin undergoes this form of translation, traction and stretching; yet, with the exception of open wounds, it returns to its initial position.” Full thickness wounds and other injuries that resolve through scar tissue formation, never regain normal tensile strength, function, cosmesis, texture or pliability disrupting the skin’s biotensegrity. Fundamental and irreparable changes occur in the dermis and deep tissue structures disrupting the skin’s biological rhythm and connection to the other systems.

The movement attributed to the skin is called elasticity, yet that term belies its true intricacies. It is a rhythm connecting all components of the human body, from the smallest cell to the largest organ. Dr. Guimberteau describes that “under the dermis and hypodermis there is a highly mobile tissue encompassing everything else and penetrating what is known as the undermined plane. When this tissue is tracked upward… curious movements occur due to the bursting of vacuoles at atmospheric pressure demonstrating the existence of hydraulic systems under different levels of pressure.” Similarly, fascia is another organ or system with a unique 3-dimensional metabolic and mechanical matrix. It consists of soft, collagen derived loose and dense connective tissue that permeates the body. “It incorporates

“The movement attributed to the skin is called elasticity, yet that term belies its true intricacies. It is a rhythm connecting all components of the human body, from the smallest cell to the largest organ.”

elements such as adipose tissue, adventitia and neurovascular sheaths, aponeuroses, deep and superficial fasciae, epineurium, joint capsules, ligaments, membranes, meninges, myofascial expansions, periostea, retinacular, septa, tendons, visceral fasciae, and all the intramuscular and intermuscular connective tissue including endo-/peri-/epimysium… interpenetrates and surrounds all organs, muscles, bones and nerve fibers, endowing the body with a functional structure, and providing an environment that enables all body systems to operate in an integrated manner.”8 The solid fascia structures described above divide, support and connect the different parts of the body into a connected system; liquid fascia,8 comprised of blood and lymph, transports messages and nourishes the solid fascia. This liquid fascia also determines the health of the tissues. “As water shapes rocks, bodily fluids modify shapes and functions of the bodily structures. Bodily fluids are silent witnesses of the mechanotransductive information, allowing adaptation and life, transporting biochemical and hormonal signals.”8 A poignant example of this is demonstrated through the endothelial glycocalyx layer (EGL). Mechanotransduction is the mechanism that allows the EGL, a gel-like matrix with hairlike projections extending into the lumen of all vessels, to act like a molecular sieve by regulating fluid and macromolecule movement (liquid fascia) out of the vascular space. Blood flow shear forces (mechanotransduction) act on the vascular endothelial cells to produce and release nitric oxide. This in turn, dilates the vessel.9-10 With trauma, disease, and other conditions, this normal process of the microcirculation, can lead to modifications in the shape and function of the areas involved by inducing edema. This, when coupled with other comorbidities or issues, can result in further dysregulation in biotensegrity; problems with mobility and function, lymphatic dermopathy, and infection to name a few.

Armed with this knowledge, we can begin to look differently at preventative strategies to maintain system wide health. All things are connected; it is up to us to put the puzzle pieces together and to be open to the remarkable synergies that can be found in unlikely places to help us explain our building blocks. This in turn, will help preserve biotensegrity to allow for optimal functioning in all environments. Although form follows function, form is influenced by its environment.

References

1. Ingber D. The Architecture of Life. Sci Am. 1998 Jan;278(1):48-57. doi:10.1038/ scientificamerican0198-48.

2. Ingber D. Tensegrity: The architectural basis of cellular mechanotransduction. Annu. Rev. Physiol. 1997;59:575-599.

3. Ingber D, Jamieson J. Cells as tensegrity structures: architectural regulation of histodifferentiation by physical forces transduced over basement membrane. In Gene Expression During Normal and Malignant Differentiation, ed. LC Andersson, CG Gahmberg, P Ekblom, pp. 13=32. Orlando, FL: Academic.

4. Pienta K, Coffey D. Cellular harmonic information transfer through a tissue tensegritymatrix system. Med. Hypoth. 1991;34:88-95.

5. Narjana T, Sanchez-Esteban J. Mechanotransduction as an adaptation to gravity. Front Pediatr. 2016;4:140. doi:10.3389/fed.2016.00140.

6. Carlson J. Lymphedema and subclinical lymphostasis (microlymphedema) facilitate cutaneous infection, inflammatory dermatoses, and neoplasia: A locus minoris resistentiae. Clinics in Dermatology. 2014;32(5):599-615.

7. Ruocco V, Ruocco E, Brunetti G, Sanguiliano S, Wolf R. Opportunistic localization of skin lesions on vulnerable areas. Clinics in Dermatology. 2011;29(5):483-488.

8. Bordoni B, Marelli F, Morabito B, Castanga R. A New Concept of Biotensegrity Incorporating Liquid Tissues: Blood and Lymph. J Evidence-Based Integ Med. 2018;23:110.

9. Biddle C. Like a slippery fish, a little slime is a good thing: the glycocalyx revealed. AANA Journal. 2013;81(6):473-80.

10. Weinbaum S, Tarbell J, Damiano E. The structure and function of the endothelial glycocalyx layer. Annu Rev biomed Eng. 2007;9:121-167.

11. Dr. Jean-Claude Guimberteau. Strolling under the Skin. 2014. [Internet]. Available from: https://www.youtube.com/watch?v=eW0lvOVKDxE&t=484s

“Armed with this knowledge, we can begin to look differently at preventative strategies to maintain system wide health.”