Introduction to Tissue Engineering

Flashcards covering definitions, therapies, processes, and basic cell behaviors in tissue engineering based on the lecture transcript.

Tissue Engineering

An interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function.

Autografting

Tissue that is transplanted from one part of a body to another part in the same individual, which does not induce rejection of the implanted organ.

Ex: skin, bone, anterior cruciate ligament reconstruction with patellar tendon

Autograft Pros and Cons

Pros: best clinical results, no disease transfer, no rejection

Cons: limited available tissues, high cost (double)

Allografting

The use of tissue or organs donated by either living or deceased human donors, which carries a finite risk of disease transfer and rejection complications.

Ex: heart, lungs, liver, kidneys, bone marrow, cartilage, and tendons

Allografting pros and cons

Pro: no second surgery, immediate structural support

Cons: donor shortage, high chance of rejection, less consistent, potential disease transfer

Xenografting

A procedure involving the transplantation, implantation, or infusion into a human recipient of live cells, tissues, or organs from a nonhuman animal source.

Xenografting Pros and Cons

Pros: increases supply of available tissues

Cons: high chance of rejection, disease transmission, ethical concerns

Human Organ Transplant Act (HOTA)

A Singapore act under which kidneys, liver, heart, and corneas can be recovered in the event of death for transplantation for covered citizens and Permanent Residents.

Medical Device

An instrument, apparatus, implement, machine, or implant recognized in the US Pharmacopoeia intended for use in the diagnosis, cure, or prevention of disease.

Types of Medical Devices

1. Implantables

2. Wearables

Scaffold

A highly porous 3D substrate that provides a surface where cells adhere, proliferate, and generate essential elements that make up living tissue.

Tissue Engineering

Applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue funciton

Extracellular Matrix (ECM)

A network of macromolecules (proteoglycans and fibrous proteins like collagen and elastin) occupying the extracellular area that provides structural support and bioactive cues.

3 Key elements in TE

Biomaterials, cells, and signals

Bioprinting

A technology that enables scalable mass production, accurate 3D positioning of different cell types, and the culture of tissues with high cell density levels.

Integrins

Transmembrane receptors through which cell protrusions attach to the surrounding extracellular matrix (ECM) or neighboring cells during the migration cycle.

5-Step Migration Cycle

The translation of cells from one location to another consisting of Extension, Adhesion, Contraction, Release, and Recycling.

Cell Proliferation

The increase in cell number as a result of cell growth and division, affected by growth factors, mechanical signals, and perfusion of nutrients.

Cell Differentiation

The process by which a stem cell can become any one of the 220 different cells in the body, such as heart, brain, or lung cells.

Apoptosis

A genetically determined process of cell death that removes unneeded or damaged cells.

Necrosis

An uncontrolled process of cell death typically caused by external events and signals.

Smooth muscle cell motility

The movement of smooth muscle cells, where maximal cell speed was observed on a $51.9\,kPa$ substrate.

Actin filaments

The basic structural component found in cellular structures like filopodium and lamellipodium used for cell motility and substrate sensing.