Tissue Implants: Biological and Synthetic Materials

Bone grafts harvested from one part of the body and moved to another for reconstructive purposes.

Artificial materials used as substitutes for damaged or missing facial tissues.

A material that mimics the body's natural tissues and can remain stable over time

Physical characteristics of a material, such as strength, flexibility and elasticity, that are relevant to its use in the body.

A mesh implant with many small openings which allows for strong connection to surrounding tissue.

An implant without many openings, which is surrounded by a protective layer of fibrous tissue

The process where an implant breaks down over time

The body's response to an implanted material including possible inflammation, rejection, or tissue growth around the implant

Cartilage's stress-strain relationship is non-linear; it becomes stiffer as strain increases. Initially, load is absorbed by elastic deformation, and over time, by the displacement of water molecules between collagen fibers.

Bone's stress-strain relationship is mostly linear but plateaus at around 1% strain, depending on the rate of strain.

A tissue or organ transplant from one part of the same individual's body to another.

A tissue transplant between two individuals of the same species.

Factors that can lead to cartilage graft failure, like blood in the surgical site, dead space, rough implant surface, lack of smooth cartilage contact, or inadequate soft tissue covering.

Factors that help long-term graft survival, including smooth implants and good contact with surrounding tissues, preventing dead space or blood.

A permanent implant that doesn't trigger a chronic inflammatory response, maintaining its position and size over time.

The gradual dissipation of load in cartilage over time due to the shifting of water molecules in the spaces between collagen fibers.

Polydimethylsiloxane, also known as silicone, is used to augment tissues of the face. It removes depressions or wrinkles.

Collagen is used in an injectable form to remove depressions and wrinkles and mask acne scars.

Correction with collagen requires continuous maintenance due to the limited persistence of the implant (6 to 9 months).

Polydimethylsiloxane (PDMS) is a widely used solid implant in areas of the face, including the chin and cheek.

Implants are inserted after soaking in an antibiotic solution; patients are given antibiotics before and after surgery.

Bone erosion is an infrequent complication of PDMS implants.

Polyterafluroroethyolene (PTFE) is a solid implant containing either carbon fibers or aluminum oxide as reinforcing materials.

PTFE is manufactured as sponges with pores occupying about 70% of the volume.

The process of artery walls thickening due to fatty deposits, often leading to restricted blood flow and an increased risk of cardiovascular disease.

PVA hydrogels are used in biomaterials due to their adjustable stiffness controlled by factors like polymer concentration, freezing time, and the number of freeze-thaw cycles.

A mathematical model used to analyze the viscoelastic behavior of materials like PVA hydrogel, where stress and strain are related over time.

A parameter in the Maxwell model representing the time it takes for a material to relax after an applied stress, indicating how quickly it returns to its original state.

A gradual change in the stiffness of a material across its structure, allowing for tailored responses in biological applications.

Materials designed to replicate the behavior of real tissues, helping scientists understand how tissues function and predict diseases.

Materials that imitate the properties of blood vessels, allowing researchers to study blood flow and identify potential health problems.

A medical imaging technique that uses sound waves to assess blood flow in the body, particularly in arteries.

The difference in frequency between the sound waves sent out and those reflected back, revealing the speed of blood flow.

Blood flow that is smooth and consistent, indicating a healthy artery.

Irregular blood flow, often signifying a blockage or narrowing in an artery.

A major artery in the neck that supplies blood to the brain and head.

Using Doppler ultrasound to create images that show blood flow patterns in arteries.

A form of calcium found in bone, often used in reconstructive surgeries. It's brittle, so it's combined with a polymer to make it more flexible.

A new bone graft material made from a mix of hydroxyapatite and a polymer, created using 3D printing technology.

A material that has many tiny holes or pores, which allows blood vessels to grow into the area, promoting healing.

A type of plastic incredibly strong and lightweight, even exceeding the strength of steel.

A technique used to create porous structures in UHMWPE by physically mixing ingredients in a solid state.

A bone scaffold with two layers: a solid outer layer for strength and a porous inner layer for blood vessel growth.

Artificial materials used to replace or repair damaged bone, like the 'Iron Polymer' example.

The hard, outer layer of bone providing structural support.

The process of designing and creating artificial tissues to replace or regenerate damaged ones, often using cells, scaffolds, and growth factors.

A three-dimensional structure that provides a framework for cells to grow and organize into a tissue. Usually made from synthetic materials.

Proteins that stimulate cell growth, division, and differentiation. They help cells specialize and form a functional tissue.

The process by which cells sense and respond to mechanical forces, such as pressure or stretching.

The study of how fluids flow and deform under different conditions, important for designing artificial tissues that behave like real ones.

A property of some materials where they become stiffer as they are stretched or deformed.

The ability of a porous material, like a tissue scaffold, to deform and recover elastically due to the movement of fluids through its pores.

The smooth, specialized tissue that covers the ends of bones in joints, providing cushioning and reducing friction.

Rheology is the study of how materials flow and deform under stress. It helps us understand how liquids, like honey, and solids, like dough, behave.

Viscosity is a measure of how viscous a fluid is, or how resistant it is to flow. Higher viscosity means the fluid is thicker and flows more slowly.

A Newtonian fluid has a fixed viscosity at a given temperature. This means its flow rate changes linearly in response to the applied force.

A Non-Newtonian fluid's viscosity changes depending on the force applied to it. They can be either shear-thinning (thinner with more force) or shear-thickening (thicker with more force).

Viscoelasticity describes materials exhibiting both viscous and elastic behavior. They deform under stress but also partially recover their original shape after the stress is removed.

A material's resistance to deformation under stress. It's a measure of how stiff a material is.

The amount of deformation a material undergoes when a stress is applied. It's a measure of how much the material stretches or compresses.

A measure of a material's stiffness when subjected to oscillating stress or strain. Represents both elastic and viscous components.

The elastic component of the complex modulus. It represents how much energy is stored in a material during deformation.

The viscous component of the complex modulus. It represents how much energy is lost in a material during deformation.

The distance over which a filament maintains a straight orientation before bending due to thermal fluctuations.

Measures a filament's resistance to bending (κ) and stretching (µ).

A material's tendency to become stiffer as it is stretched or compressed, often observed in biological tissues.

A complex, three-dimensional structure formed by interconnected biopolymers (like proteins or polysaccharides), often found in biological materials.

Study of a material's response to shear stress, which is a force applied parallel to a surface, often impacting the material's shape and flow properties.

A force acting perpendicular to a surface, often arising in materials subjected to shear.

A phenomenon where shear deformation in a material induces a normal force, either compressive or tensile, depending on the material's properties.

A measure of a fluid's resistance to flow - thicker fluids have higher viscosity.

The time it takes for a material to return to its original shape after stress is removed, indicating how quickly its deformation recovers.

A synthetic implant made from aragonite, a form of calcium carbonate derived from coral exoskeletons, designed to repair damaged cartilage. It acts as a scaffold, promoting natural regeneration of articular cartilage.

A form of calcium carbonate derived from coral exoskeletons, used in the Agili-C implant to promote cartilage regeneration.

Agili-C is inserted into the damaged cartilage area. It gradually absorbs, allowing stem cells and healing factors to migrate to the site, promoting new bone and cartilage growth.

The key players in designing artificial tissues include understanding the mechanical properties of materials, how they interact with cells, and the healing process.

Cartilage, the smooth tissue in joints, is difficult to repair because it lacks blood vessels, making healing slow. Current treatments often fail to restore its original strength and flexibility.

This scaffold uses gelatin (from collagen) and hydroxyapatite (a mineral found in bone) to create a structure that mimics cartilage's makeup. It helps cells grow and differentiate.

Transglutaminase acts like a 'molecular zipper,' creating strong links between gelatin molecules, making the scaffold more stable and durable.

Pigs are often used in cartilage research because their knee joints have similar size and structure to human knees, making them a suitable model for testing.

This artificial cartilage uses bacterial cellulose (BV) to mimic collagen's strength and polyvinyl alcohol (PVA) to act like the proteoglycans that give cartilage its gel-like properties.

Cartilage is mainly composed of collagen fibers, which provide strength and structural support, and a gel-like matrix of proteoglycans, which provide cushioning and lubrication.

Cells, particularly MSCs, play a crucial role in cartilage repair. They can differentiate into cartilage cells (chondrocytes) and produce the necessary extracellular matrix components.

MSCs, when differentiated into chondrocytes, produce the vital components for cartilage regeneration, such as collagen and proteoglycans, which are crucial for its structure and function.

A surface designed to mimic the natural texture of tissues, providing mechanical signals that influence cell behavior.

A technique used to create tiny, precisely shaped structures on a surface, often used in tissue engineering to create scaffolds with specific architectures.

A 3D printing technique used to create complex, porous structures for tissue engineering scaffolds.

A computer-aided design method used to create the optimal shape and pore arrangement for tissue engineering scaffolds.

The resistance of a material to deformation under applied force, a crucial factor in creating tissues that match the natural properties of the body.

A significant change in the way tissues are designed and created, moving from simple implants to structures that actively promote tissue regeneration.

The goal of tissue engineering is not just to replace lost tissue but to restore its original function, allowing the body to work properly again.

A measure of a material's stiffness, indicating its resistance to deformation under stress. Higher modulus means the material is stiffer.

A material's resistance to deformation when a force is applied parallel to its surface. It's like a measure of how much it wants to 'slide' instead of compress.

The distance over which a filament maintains a straight orientation before bending due to thermal fluctuations. It's like a measure of its 'straightness'.

A measure of a fluid's resistance to flow - thicker fluids have higher viscosity. It's like how easily a fluid 'pours' or 'spreads'.

The ability of a biopolymer network (like tissue) to stretch or deform without breaking under strain. This is important for tissues to withstand forces without tearing.

The maximum stress a biopolymer network can withstand before it starts to fracture or break apart during a stress test. This peak occurs at a specific strain.

The breaking or tearing of a biopolymer network, often occurring after reaching the peak stress during a stress test. This process is influenced by how the network is connected and its ability to stretch (extensibility).

Important factors in how well a biopolymer network can handle stress. Connectivity refers to how linked the components are within the network, while plasticity refers to the ability of a material to deform and retain its shape even after stress is removed.

A type of biomaterial hydrogel made from bacterial cellulose (BC) and polyvinyl alcohol (PVA), designed to mimic the properties of cartilage.

The process of heating the BC-PVA hydrogel to a specific temperature for a certain time to increase its crystallinity and solid content, improving its mechanical strength.

The ability of a material to withstand abrasion and wear. The BC-PVA hydrogel showed superior wear resistance compared to native cartilage.

The ability of a material to resist forces applied parallel to its surface. The BC-PVA hydrogel exhibited significantly greater shear strength than porcine cartilage.

The ability of an implant to securely attach to the surrounding tissues. The BC-PVA hydrogel demonstrated strong attachment to titanium, which can integrate with bone.

A higher degree of order and regularity in the arrangement of molecules within a material, which often leads to improved mechanical properties.

The amount of solid material present in a substance, which can significantly influence its mechanical strength and stability.

These properties describe how the biomaterial reacts to applied forces, including its stiffness, strength, and ability to resist deformation.