Introduction to Biomedical Materials
37 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary reason macrophages are activated when encountering synthetic materials?

  • They are detecting the presence of bacteria on the material, initiating a defense mechanism
  • They are recognizing specific antigens on the material, triggering an immune response
  • They are attempting to degrade the material, leading to the release of inflammatory cytokines (correct)
  • They are directly damaged by the material, causing them to release inflammatory signals

How does the biocompatibility of a synthetic material affect the inflammatory response?

  • The biocompatibility of a material does not influence the inflammatory response.
  • Biocompatible materials cause a delayed but more severe inflammatory response compared to non-biocompatible materials.
  • Biocompatible materials elicit a less intense inflammatory response due to their ability to integrate well with the host. (correct)
  • Highly biocompatible materials trigger a stronger inflammatory response because they are difficult to degrade.

What is the typical outcome of the late-stage tissue reaction to a synthetic material?

  • A thick fibrous capsule formation surrounding the material, preventing further integration
  • A thin fibrous capsule encapsulating the material, minimizing further interaction (correct)
  • A persistent inflammatory response leading to tissue damage and rejection
  • Complete degradation and absorption of the material by the surrounding tissue

What is the first step in biofilm formation on a biomaterial surface?

<p>The attachment of bacteria to the biomaterial's surface (D)</p> Signup and view all the answers

How do slippery liquid-infused porous surfaces (SLIPS) prevent fouling?

<p>By releasing a surface liquid layer that inhibits long-term attachment of organisms (A)</p> Signup and view all the answers

Which of the following is NOT a topic covered in the course?

<p>Organic chemistry fundamentals (B)</p> Signup and view all the answers

According to the 2018 definition, what is the primary purpose of a biomaterial?

<p>To influence biological processes for therapeutic or diagnostic purposes (A)</p> Signup and view all the answers

Which of the following materials would most likely NOT be considered a biomaterial as defined by the 1986 consensus?

<p>A natural rubber used in a disposable glove (D)</p> Signup and view all the answers

What is the primary method by which 60Co isotope sterilizes materials?

<p>By causing ionization of nucleic acids (A)</p> Signup and view all the answers

Which is a characteristic of the environment where the 60Co isotope is stored when the irradiator is not in use?

<p>It is submerged in a water-filled pool (C)</p> Signup and view all the answers

What is the most commonly validated dose used to sterilize medical products?

<p>25 kGy (D)</p> Signup and view all the answers

Which material is NOT compatible with gamma radiation sterilization?

<p>PTFE (C)</p> Signup and view all the answers

What are the two key effects of gamma radiation on organic matter as mentioned in the content?

<p>Chain scission and crosslinking (D)</p> Signup and view all the answers

Which of the following is a relevant material design property for the functional performance of an intraocular contact lens?

<p>Transparency (D)</p> Signup and view all the answers

What is one characteristic that defines the biocompatibility of a material?

<p>It should be non-immunogenic. (D)</p> Signup and view all the answers

Which design property is essential for load transmission and stress distribution in knee joint replacements?

<p>High mechanical stability (B)</p> Signup and view all the answers

What factor is NOT involved in assessing the functional performance of a biomaterial?

<p>Cost of production (B)</p> Signup and view all the answers

In the context of surgical sutures, what does resorbability refer to?

<p>The gradual breakdown and absorption of the material in the body (D)</p> Signup and view all the answers

Which property is critical to ensure a material resists infection?

<p>Non-fouling (D)</p> Signup and view all the answers

Which option describes a scenario where a material might NOT demonstrate suitable functional performance?

<p>A material that becomes brittle under stress (C)</p> Signup and view all the answers

Which of these properties directly affects the mechanical performance of a resorbable suturing thread?

<p>Tensile strength over time (B)</p> Signup and view all the answers

What is a major component of injectable bone cement used in orthopedic implants?

<p>Poly(methyl methacrylate) (D)</p> Signup and view all the answers

Which biomaterial is primarily used for soft, hydrogel contact lenses?

<p>Poly(2-hydroxymethyl methacrylate) (D)</p> Signup and view all the answers

What characteristic describes Poly(acrylic acid) in medical applications?

<p>Forms ionic crosslinks with cations (B)</p> Signup and view all the answers

Which material is known for its good chemical resistance and tensile strength used in sutures?

<p>Poly(propylene) (A)</p> Signup and view all the answers

What is one of the major uses of High Density Poly(ethylene)?

<p>Artificial hips (B)</p> Signup and view all the answers

What characteristic of Poly(tetrafluorethylene) makes it suitable for vascular grafts?

<p>Flexible and low surface energy (C)</p> Signup and view all the answers

What is true about Poly(dimethylsiloxane) in surgical applications?

<p>It is used in prostheses like heart valves (A)</p> Signup and view all the answers

Which characteristic is associated with Poly(methyl methacrylate)?

<p>Amorphous and transparent (C)</p> Signup and view all the answers

What is the main purpose of the coagulation cascade in the context of biomaterials interacting with blood?

<p>To initiate a series of reactions that ultimately leads to the formation of a thrombus (B)</p> Signup and view all the answers

What is the role of thrombin in the coagulation cascade?

<p>It converts fibrinogen into fibrin, which forms the fibrin clot (D)</p> Signup and view all the answers

Which of the following factors is NOT involved in the extrinsic pathway of the coagulation cascade?

<p>Factor VIIIa (A)</p> Signup and view all the answers

How do the extrinsic and intrinsic pathways of the coagulation cascade converge?

<p>Both pathways lead to the activation of factor X, which triggers the common pathway (D)</p> Signup and view all the answers

What is the main difference between the extrinsic and intrinsic pathways of the coagulation cascade?

<p>The extrinsic pathway is initiated by tissue factor, while the intrinsic pathway is triggered by contact with a foreign surface (C)</p> Signup and view all the answers

Which of the following is NOT a manufacturing criterion considered for biomaterials used in medical devices?

<p>Impact of the device on the patient's immune system (C)</p> Signup and view all the answers

What are the advantages of using biomaterials in medical devices?

<p>Biomaterials can be designed to mimic the properties of natural tissues and promote healing (B)</p> Signup and view all the answers

What is the 'Expected Lifetime' in the context of a medical device?

<p>The time period during which the device is expected to function as designed (B)</p> Signup and view all the answers

Flashcards

Functional Performance

A materials ability to maintain its desired properties under the specific conditions of use.

Biocompatibility

The ability of a material to be compatible with living tissue, without causing harmful reactions.

Host Response

How the chosen material will affect the surrounding tissue.

Mechanical Stability

A biomaterial must be designed to withstand the specific stresses and strains of the application.

Signup and view all the flashcards

Degradability

The material's resistance to breaking down or degrading over time.

Signup and view all the flashcards

Biofouling resistance

The material must resist sticking to surrounding tissue or foreign particles.

Signup and view all the flashcards

Non-immunogenic

The material must not cause an immune response, like rejection or inflammation.

Signup and view all the flashcards

Non-toxic

The material must not be harmful to cells or tissues.

Signup and view all the flashcards

Biomaterial

A material designed to interact with biological systems to assess, treat, enhance, or replace body tissues, organs, or functions.

Signup and view all the flashcards

Non-fouling and Non-thrombogenic Polymers

Biomaterials that resist the build-up of unwanted biological material, like bacterial colonies or blood clots, on their surfaces.

Signup and view all the flashcards

Immune Response to Biomaterials

The body's natural reaction to a foreign material, potentially leading to inflammation, rejection, or other complications.

Signup and view all the flashcards

Smart Textiles, Intelligent Implants, Wearable Devices, and Biosensors

Materials that can sense and respond to changes in their environment, enabling intelligent functions in medical devices.

Signup and view all the flashcards

Definition of Biomaterials for the Twenty-First Century

A comprehensive and evolving definition of biomaterials that emphasizes their intended purpose and interactions with living systems.

Signup and view all the flashcards

Biomaterial Evaluation

The process of evaluating the properties and efficacy of a material for its intended use in a biological system.

Signup and view all the flashcards

Case Studies: Medical Devices

A detailed analysis of how a biomaterial is used in a specific medical device.

Signup and view all the flashcards

Presentations of Commercial Biomaterials

A presentation showcasing the commercial aspects of a specific biomaterial and its application in a medical device.

Signup and view all the flashcards

Gamma Radiation Sterilization

A process that uses gamma rays emitted from a radioactive cobalt-60 source to kill microorganisms on medical products.

Signup and view all the flashcards

Radiation Dose

The amount of radiation absorbed by a material, measured in Grays (Gy).

Signup and view all the flashcards

Half-Life

The time it takes for half of the radioactive material to decay.

Signup and view all the flashcards

Radiation Shielding

A material that absorbs radiation to protect people from harmful exposure.

Signup and view all the flashcards

Medical Products Sterilizable by Gamma Radiation

Medical devices that are commonly sterilized using gamma radiation.

Signup and view all the flashcards

Foreign Body Reaction

When synthetic materials are implanted, the body often tries to get rid of them by engulfing them. This process usually fails, leading to macrophages becoming activated and releasing inflammatory signals. The material's biocompatibility influences how much inflammation happens.

Signup and view all the flashcards

Encapsulation

A layer of fibrous (connective) tissue that forms around an implanted material, effectively isolating it from the surrounding tissue. This encapsulation is a natural response to foreign objects.

Signup and view all the flashcards

Mononuclear Giant Cells

These giant cells are found near implants and are a sign of a strong reaction by the body.

Signup and view all the flashcards

Antifouling

The ability of a surface to resist the attachment of microorganisms, like bacteria, which can lead to infection.

Signup and view all the flashcards

SLIPS

A slippery liquid-infused porous surface (SLIPS) is a material design that resists the attachment of bacteria and other microorganisms. It works by releasing a thin liquid layer that prevents organisms from sticking.

Signup and view all the flashcards

Poly(methyl methacrylate) (PMMA)

A transparent, glassy polymer commonly used in orthopedic implants, intraocular lenses, and hard contact lenses. It's known for its strength and biocompatibility.

Signup and view all the flashcards

Poly(2-hydroxymethyl methacrylate) (pHEMA)

A soft, hydrophilic polymer used in soft contact lenses. It's characterized by its low protein adsorption, making it comfortable for the eye.

Signup and view all the flashcards

Poly(acrylic acid) (PAA)

A hydrophilic polymer that forms crosslinked networks, commonly found in dental cements and mucoadhesive drug delivery systems. It can form strong bonds with the mucous membranes in the body.

Signup and view all the flashcards

High Density Poly(ethylene) (HDPE)

A strong, tough, and wear-resistant polymer used in artificial hips, prosthetic joints, and medical tubing. It's known for its mechanical properties, making it suitable for structural applications.

Signup and view all the flashcards

Poly(propylene) (PP)

A durable and chemically resistant polymer commonly used in sutures, meshes for hernia repair, and other medical applications. It's known for its tensile strength and its ability to hold stitches together.

Signup and view all the flashcards

Poly(tetrafluoroethylene) (PTFE)

A flexible, low-friction polymer frequently used in catheters, vascular grafts, blood storage bags, and dialysis tubes due to its smooth surface and low protein adsorption.

Signup and view all the flashcards

Poly(dimethylsiloxane) (PDMS)

A flexible, biocompatible polymer used in prostheses like finger joints, heart valves, breast implants, and nose reconstruction. It can mimic the properties of human tissues.

Signup and view all the flashcards

Blood Thrombosis on Non-Physiological Surfaces

The sequence of events that occur when a non-physiological surface comes into contact with blood, leading to clot formation.

Signup and view all the flashcards

Plasma Protein Deposition

The initial step in blood thrombosis, where plasma proteins like fibrinogen quickly attach to the foreign surface.

Signup and view all the flashcards

Platelet and Leukocyte Adhesion

The second stage of blood thrombosis, where platelets and white blood cells adhere to the deposited plasma proteins.

Signup and view all the flashcards

Blood Coagulation

The final stage of blood thrombosis, where a fibrin clot forms and stops bleeding.

Signup and view all the flashcards

Coagulation Cascade

The process by which the body naturally stops bleeding from injured blood vessels.

Signup and view all the flashcards

Extrinsic Pathway

A pathway in the coagulation cascade initiated by tissue factor, which is released from injured tissues.

Signup and view all the flashcards

Intrinsic Pathway

A pathway in the coagulation cascade triggered by activated factor XII, which is activated by contact with negatively charged surfaces. This pathway amplifies the clotting process.

Signup and view all the flashcards

Common Pathway

The final shared pathway of both the extrinsic and intrinsic pathways, culminating in the formation of a fibrin clot.

Signup and view all the flashcards

Study Notes

Introduction to Biomedical Materials/Polymers

  • Biomaterials Science: An introduction to Materials in Medicine, 3rd Edition, edited by B. D. Ratner, A. S. Hoffman, F. J. Schoen, J. E. Lemons, Elsevier 2013

Lecture Plan

  • 15.10.2024: Fundamentals Biomedical Materials. Selection criteria for biomaterials for medical devices (del Campo, Müller, Asensio)

  • 22.10.2024: Physicochemical properties of polymer materials of relevance for biomedical applications, and methods to characterize them (del Campo)

  • 29.10.2024: Synthetic biomedical polymers, resorbable (I) (del Campo)

  • 05.11.2024: Synthetic biomedical polymers, resorbable (II) (del Campo)

  • 12.11.2024: Synthetic biomedical polymers, non-resorbable (I) (del Campo)

  • 19.11.2024: Biomedical hydrogels (Asensio)

  • 26.11.2024: Additive Manufacture of biomedical polymers (Steudter)

  • 03.12.2024: Protein adsorption on surfaces. Non-fouling and non-thrombogenic polymers (Sankaran)

  • 10.12.2024: Immune response to biomaterials (Trujillo)

  • 17.12.2024: Smart Textiles, Intelligent Implants, Wearable devices and biosensors (Sankaran)

  • 07.01.2025: Case studies: medical devices (del Campo)

  • 14.01.2025: Case studies: medical devices (del Campo)

  • 28.01.2025: EXAM (multiple choice text) (del Campo, Asensio)

  • 04.02.2025: Presentations, students (del Campo, Asensio)

  • 11.02.2025: Presentations, students (del Campo, Asensio)

  • 18.02.2025: Presentations, students (del Campo, Asensio)

  • Evaluation: Exam (multiple choice) and oral presentation of a commercial biomaterial as part of a commercial medical device.

Biomaterial Definition

  • "A material intended to interface with biological systems, to evaluate, treat, augment or replace any tissue, organ or function of the body." (1986 Consensus Conference)
  • "A material designed to take a form which can direct, through interactions with living systems, the course of any therapeutic or diagnostic procedure." (2018 Consensus Conference)

Biomaterial Examples

  • External: Contact lenses, bandages, skin and wound dressings, dialysis membranes.
  • Implanted: Restorative implants, sutures, stents, pacemakers, brain electrodes, implants to regulate fertility.
  • Scaffolds for regenerative medicine and tissue engineering (e.g., breast implants).
  • Carriers for drugs (nanomedicine).
  • Man-machine interface/wearable electronics.
  • Cell culture dishes or microarrays for diagnostic/theranostic assays.

Biomaterials Across Material Classes

  • Metal, ceramic, polymeric, composites (examples provided in image)

Why Polymers as Biomaterials?

  • Stiff/Flexible/Ductile
  • Easy to process (low temperatures, various morphologies)
  • Lightweight
  • Organic, flexible chemistry and functionalization
  • Hydrated (hydrogels)
  • Cost-effective

Outline

  • History/Overview Biomaterials
  • Selection Criteria of Biomaterials
  • Classification of Biomaterials

Biomaterials Science is a Young Field

  • No "biomaterial" concept 50 years ago
  • No medical device manufacturers except for external prosthetics, fracture fixation, eye implants, dental devices.
  • No regulations, no understanding of biocompatibility, no courses on biomaterials.
  • Today: Expected continuous growth, relevant market, stringent regulation, multidisciplinary (chemistry + biology + medicine + materials engineering).

Prehistory of Biomaterials

  • 3000 BCE: Egyptians used linen sutures.
  • 600 CE: Mayans used seashells.
  • 1775: First example of bone fracture fixation with metal wire.
  • 1829: HS Levert toxicity studies.
  • 1860: Adolf Fick glass contact lenses, PMMA contact lenses developed and entered market.
  • 1870's: Lister's aseptic surgical materials.

The Era of the "Surgeon Hero" (1940-1960)

  • Parallel development of high-performance metals, ceramics, and especially polymers.
  • Materials manufactured for cars or airplanes were adapted by surgeons for medical challenges.
  • Lack of regulation; solutions tested on an ad hoc basis.
  • Key milestones include: development of nylon sutures, cellulose for vascular wrapping (and detecting fibrotic reaction), PMMA, polyethylene implants, implantable pacemakers, Teflon for dialysis, artificial heart pumps.

The First "Plastics"

  • Historical timeline of polymer development (e.g., PVC, Celloid, Galalithe, etc.).

The Era of Designed Biomaterials (1960s)

  • New materials designed specifically for medical applications (biodegradable polymers, bioactive ceramics).
  • Development of technologies for biomaterial fabrication (polyester fibers, cellulose acetate).
  • Modification of materials for specific biological properties (e.g., heparin surface modification).
  • 1976 regulation for testing and production of medical devices.

Most Biomaterials Applied Today

  • Based on biomaterials from the 1960-1980s.
  • Examples provided.

Poly(methyl methacrylate) (PMMA)

  • Major component of injectable bone cement, intraocular lenses, and hard contact lenses.
  • Amorphous, transparent and glassy at room temperature.

Poly(2-hydroxymethyl methacrylate) (PHEMA)

  • Major component of soft, hydrogel contact lenses.
  • Transparent, hydrophilic, non-fouling (low protein adsorption).

Poly(acrylic acid) (PAA)

  • Major component of dental cements (mixed with inorganic salts) and mucoadhesive hydrogels

High Density Poly(ethylene) (HDPE)

  • Major uses: artificial hips and prosthetic joints, tubing for drains and catheters.
  • Mechanically resistant, tough, wear resistant.

Poly(propylene) (PP)

  • Sutures, meshes for hernia repair.
  • Good chemical, tensile strength

Poly(tetrafluoroethylene) (PTFE, Teflon):

  • Catheters, vascular grafts (Gore-Tex), blood storage bags, dialysis tubes.
  • Flexible
  • Low surface energy, low protein adsorption.

Poly(dimethylsiloxane) (PDMS)

  • Prostheses, heart valves, breast implants, nose reconstruction.
  • Soft elastomer
  • High oxygen permeability, low protein adsorption.

Poly(ethyleneterephthalate) (PET, Dacron)

  • Sutures, fabrics, meshes for hernia repair, ligament reconstruction.
  • High tensile strength, mostly used in fiber form.

Poly(D,L-lactide-co-glycolide) (PLGA)

  • Resorbable surgical sutures, drug delivery, orthopedic appliances.
  • Degradable.

Polyurethanes

  • Pacemaker insulation, catheters, vascular grafts, heart assist pumps, artificial heart bladders, and wound dressing
  • Tough elastomers, flexibility in the properties depending on monomer selection.

Biomaterials Development: Research to Biomedical Product

  • Traditional design parameters
  • Active clinical feedback; new parameters, animal models vs. human outcome
  • In vitro testing, In vivo studies
  • Mechanism screening, high-throughput scaffolds, manage large data, systems biology
  • Clinical testing

The Contemporary Era: Responsive Carriers for Drug Delivery

  • Resorbable, responsive carriers for drug delivery

The Contemporary Era: Microneddle Skin Patches

  • Drug delivery devices

The Contemporary Era: Devices for Health Monitoring

  • Wearables for sensing with multiple functions.

The Contemporary Era: 3D Bioprinting

  • 3D printed medical devices
  • 3D printed organs

The Contemporary Era : Biomaterials for Tissue Engineering

  • 3D scaffolds for tissue regeneration.

Evolving View of Biomaterial Interactions With Immune System

  • Historical evolution of understanding.

Fouling, Biofilms, Infection

  • Biofilm formation

Antifouling Surfaces in Nature

  • Examples in nature

Slippery Liquid-Infused Porous Surfaces (SLIPS)

  • Example of a non-fouling surface

Thrombogenicity

  • Biomaterials in contact with blood

The Coagulation Cascade

  • Sequence of thrombotic interactions

The Major Factors Determining a Biomaterial Choice

  • Key factors for biomaterial selection

Manufacturing Criteria

  • Cost-effective processing, upscaling
  • Packaging
  • Stability, lifetime
  • Marketing requirements
  • Sterilization

What is the XXX Life of a Medical Device?

  • Shelf life, expiration date, expected lifetime, end of life, service life, life cycle.

Sterilization Methods

  • Autoclaving
  • Ethylene Oxide (EO) gas sterilization

y-Radiation Sterilization

  • Sterilization using ionizing radiation.

Economic Issues

  • Regulations, safety, competing products, market size, healthcare system.

Classification of Polymeric Biomaterials

  • Source, Durability, Safety/Regulation.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Biomedical Materials/Polymers Lecture 1 (PDF)

Description

This quiz explores the fundamentals of biomedical materials, including selection criteria, physicochemical properties, and various types of synthetic polymers. It also covers important applications like hydrogels and protein interactions on surfaces. Prepare to enhance your understanding of materials used in medical devices.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser