biomaterials, implantable medical devices and biomedical science:

Biomaterial, Bio-implant and Bio- device. Interaction with human tissue. Important facts And. Conclusion.

Prepared By-

Dr. Md Nazrul Islam. MBBS, M.sc.(BME).Supervised By-

Associate Prof. Ziaul Haq MBBS, MS (Orthopedic).

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Biomaterial, Bio-implant / Bio-medical device:

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Biomaterial, Bio-implant / Bio-medical device

A biomaterial is any material (other than drug), natural or synthetic, that is used to make bio-implant, biomedical device that treats, augments, or replaces any tissue, organ and/or any body function.


Bio-ImplantAny substance other than the drug made of Biomaterial-s that can be used for any period of time as part of a system that treats augments or replaces any tissues, organ, or functions of the body, AndIt is usually intended to remain there for a significant period of time.


Bio-Medical Device: Bio-Medical Device" is "an instrument, apparatus, implement, machine, contrivance, implant, in-vitro reagent, or related article including any component, part or accessory, which is:

Intended for use in the diagnosis of disease/

other conditions, or in the cure, mitigation, treatment, or prevention of disease. Intended to affect the structure /function of human system And does not achieve any of it's primary intended purposes through chemical action within or on And is not dependent upon being metabolized in the Body.

Historical Advancement: Biomaterials & Biomedical Devices Romans,Chinese,and Aztecs used gold in dentistry over 2000 years ago. 1860's: Lister develops aseptic surgical technique. Early 1900's: Bone plates used to fix fractures. 1930's: Introduction of stainless steel, cobalt chromium alloys. 1938 : First total hip prosthesis (P. Wiles). 1940's: Polymers in medicine: PMMA bone repair; cellulose for dialysis; nylon sutures. 1952: Mechanical heart valve. 1953: Dacron (polymer fiber) vascular grafts. 1958: Cemented (PMMA) joint replacement . 1960: First commercial heart valves. 1970's: PEO (poly-ethylene-oxide) protein resistant thin film coating. 1976: FDA amendment governing testing & production of biomaterials /devices. 1976: Artificial heart W. Kolff, Prof.Emeritus U of U).



Statistics: Biomaterials Biomedical Devices-

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Statistics: Biomaterials Biomedical Devices-


Biomaterial: Classification

Nonbiological

Biomaterial s:95% of total BioImplant-

BiologicalBiomaterial:05% of total BioImplant Natural Biologic Hybrid Biomaterial


Non-Biological (Synthetic) Biomaterial Non-biologicalSynthetic materials, are made of polymer/ Metal/Ceramic or Composite, suitable for implanting in a living body to Repair . Replace Augment or Regenerate damaged or diseased parts.


Metals Orthopedics'

screws/fixation Dental Implants / filler

37.4 Ti Alloys Steels Stainless37.3 CoCr Alloys

Metals are used as biomaterials due to their excellent electrical and thermal conductivity and mechanical properties. The first metal alloy developed specifically for human use was the vanadium steel .


Polymeric Biomaterials

Any one of a large and varied group of materials consisting wholly or part of a combination of carbon and hydrogen (hydrocarbons) It is also a combination of oxygen, nitrogen and other organic and inorganic elements.o Non-absorbable Polymer & o Absorbable/Biodegradable Composition Advantages Disadvantage : Not strong, deform with time, may degrade

Nylon, silicones, Resilient, PTFE, UHMWPE easy to fabricate


Ceramic Biomaterials Ceramics are defined as the art and science of making and using solid articles that have as their essential component, inorganic nonmetallic materials.Composition Advantages Highly biocompatible, inert, high modulus and compressive strength, good esthetic properties Disadvantage : Brittle, difficult to make, poor fatigue resistance

Non Biodegradable

Natural

Aluminum oxide, carbon, hydroxyapati te


Composite Biomaterials -

Composites

Fibrous Composites

CompositionPorous Composites

Advantages Strong, tailormade

Disadvantage : Difficult to make

Various combinations

Particulate Composites


BIOLOGICAL BIOMATERIAL

BIOLOGIC Stem cell based/ derived Cell/ Tissue. Stem cell based/ derived- Resorbable Collagen Medical Implant. Stem cell based/ derived-Tissue Engine -ering for Tissue /Organ Regeneration.

NATURALStem Cells Cartilage repair & Preservation of the knee

CORAL GELATIN

COLLAGEN BASEDBIO-IMPLANT REGENERATION ORGAN REGROW. STEM CELL BASEDBIO-IMPLANT REGENERATION ORGAN REGROW.

HYBRID/ OR Semi-syntheticBIOMATERIAL MADE FROM COMBINATION OF SYNTHETIC AND BIOLOGIC COMPONENTS.

BIOLICAL Cell/ TISSUE REGENERATION. BIOLOGICAL TISSUE / ORGAN REPLACEMENT.


Biological/Natural vs. synthetic materials Biological/Natural pros/cons built-in bioactivity poor mechanical strength immunogenicity (xenologous sources) lot-to-lot variation, unpredictable. Synthetic pros/cons biocompatibility may be difficult to predict, must be tested. mechanical and chemical properties readily altered. minimal lot-to-lot variation Synthetic advantages: tunable and reproducible.

Biomaterial, Bio-implant / Bio-medical device Classification

AndEvolution of Biomaterials-

Synthetic Biomaterials: First Generation Biomaterials: materials used in applications that are requested to be inert in the human body environment. Second Generation Biomaterials: designed to be Bioactive Resorbable. Third Generation Biomaterials: by combining these two properties, they are being designed to 4 stimulate specific cellular responses at the molecular level in order to help the body to heal itself.

Biologic Biomaterials: Bio- replacement-3rd Generation. Bio-regeneration- 4th Generation.


Cell and Gene-Activating Materials Genetic Control and Activation. Molecularly Tailored Resorbable. Biological Replacement Biomaterial/ Tissue/ Organ.

4th Generation Biomaterial: Biological Regenerative Biomaterial.


Performance Criteria

Biologically inert Biocompatible Non-viableMechanical strength and funtion Amenability to engineering design, manufacturing, and sterilization .not found naturally within the bodyTraditional Biomaterials And Medical Devices

Biomaterial, Bio-implant / Biomaterial device

Next Generation Biomaterials and Medical DevicesRevised Performance Criteria Biologically inert Non-viable Biocompatible Mechanical strength and function Amenability to engineering design, manufacturing, and sterilization Biodegradable Induces cell and tissue integration Smart (i.e., physiologically-responsive) Instructional (i.e., controls cell fate).

Biomaterial and Human /Biological Components Interaction Can be broadly divided / Classified into -

Biomaterial and Protein/ Blood. Biomaterial and Cell Biomaterial and Soft tissue Biomaterial and Hard Tissue/Bone.

Biomaterial And Protein, Blood, Cell And Soft Tissue Interaction:

ALL STEPS ARE APPLICABLE FOR ONLY BIO-INERT BIOMATERIAL

FOR BIOACTIVE, BIORESORPABLE IMPLANT

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Bio-implant And Biological Interaction: Immediately After ImplantationInfection Inflammation Bacterial AdhesionLeukocyte Adhesion and Activation Complement System Activation

Protein Adsorption. . . . . .. .Biomaterial Biological Tissue/ Components

Biomaterial And Tissue Interaction -

Macrophages

Fibrosis

The temporal variation in the acute inflammatory response, chronic inflammatory response, granulation tissue development, and foreign body reaction to implanted biomaterials.

1 Second to 1 Hour:

(Adapted from Ratner and Bryant)

Biomaterial And Soft tissue Interaction Materials: Polyethylene Hydroxyapatitie Polyurethane Silicone pHEMA PTFE Pyrolytic carbon Gold Titanium Short-Term Reaction: Long-Term Reaction: 1. Different protein 1. Fibrous adsorption Encapsulation 2. Varied activation of host response

Hydrophilic/Hydrophobic Metal/ceramic/polymer Hard/soft

Same Result (long term)

Sequence of events involved in inflammatory and wound healing responses leading to foreign body giant cell formation. This shows the importance of Th2 lymphocytes in thetransient chronic inflammatory phase with the production of IL-4 and IL-13, which can inducemonocyte/macrophage fusion to form foreign body giant cells.

Biomaterial And Hard Tissue/Bone InteractionBiomaterial and Hard tissue/ Bone Interaction Can be Classified into -

Morphological Interaction

Biological Interaction Bioactive Interaction Biodegradable/ Bioresorptionor Scaffold Interaction.

This implant for a total hip replacement is designed with various porous surfaces that encourage tissue in growth. Interactions Between Implant and Body in Fracture .

Biomaterial And Hard Tissue/Bone InteractionMorphological Interaction .

Implant is inert or nearly inert Device: dense, nonporous, nearly inert. Mechanism: mechanical interlocking Does not form bond with tissue (bone). Tissue response is dependent on fit rather than chemistry. Example: single crystal and polycrystalline Al2O3.

Biomaterial And Hard Tissue/Bone InteractionIrregular pore structure of porous coating in Ti5Al4V alloy for bony ingrowth, from Park and Lakes [1992]..

Biological Interaction Forms mechanical attachment viabone in growth into pores. Tissue response is complex, with several factors affecting it. Pores must be >100 m diameter so that capillaries can provide blood supply to ingrown connective tissue porous inert implants. Example-Hydroxy-apatite coated porous implants.

Biomaterial And Hard Tissue/Bone InteractionBioactive Interaction - Surface-reactive materials; elicits a specific biological response at the surface. Direct attachment by chemical bonding with bone Implant reacts chemically, at the surface- Dense, nonporous. Formation of a hydroxy-carbonate apatite 5 (HCA) on surface, when implanted Example-Bioactive glasses, bioactive glassceramics (Ceravital), hydroxyapatite (Duraptite.Calcitek); bioactive composites Palavital)..

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Osteoblast cell attachment on a composite Biomaterial surface-SEM.

The mechanism of new bone formation an bone bonding to a bioactive ceramic.

Biomaterial And Hard Tissue/ Bone InteractionBiodegradable/ Bioresorption or Scaffold Interaction Resorption rates must match repair rates of body tissue. Constituents of resorbable implant must be metabolically acceptable. Designed to degrade with time, and replaced with natural tissues. Reactions will persist until components have been removed. 5 Examples: Calcium sulfate, Tricalcium phosphate (TCP ). Challenge: Meeting strength requirements and short- term mechanical performance while regeneration of tissues is occuring.

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Protein adsorption Blood material interactions Coagulation Fibrinolysis

Platelet adhesion, activation, release Complement activation Leukocyte adhesion, activation Hemolysis Toxicity Modification of normal healing Encapsulation Foreign body reaction Pannus formation Infection Tumorgenesis

Embolization Hypersensitivity Elevation of implant elements in the blood Lymphatic particle transport

Effect of the Host on the Implant Physical mechanical effects Abrasive wear Fatigue Stress corrosion, cracking Corrosion Degeneration and dissolution Biological effects Absorption of substances from tissues Enzymatic degradation Calcification

Biomaterials Tissue Interactions Chart-

Local Interactions (At biomaterialtissue interface) Bloodmaterial interactions Toxicity Modification of healing Exaggerated Inflammation Prone to Infection

Systemic Interactions

DeviceAssociated Complications

Physical-mechanical effects Wear Embolization Fatigue Corrosion Hypersensivity Stress-corrosion cracking

Elevation ofBiological effects implant elements Adsorption of tissue Constituents by implant in blood Enzymatic degradation Calcification Lymphatic

Thrombosis/ thromboembolism Infection Exuberant or defective healing Biomaterials failure Adverse local tissue reaction Adverse systemic effect.

transport.

Selection criteria for Biomaterials-

Important Facts of Biomedical Implants/Devices -

Biomaterials and biomedical devices are used throughout the human body. 2 important aspects must be Consider before implantation: Functional performance Biocompatibility.5

(e.g. artificial knee joint). Control of blood and fluid flow (e.g. artificial heart). Space filling (e.g. cosmetic surgery). Electrical stimuli (e.g. pacemaker). Light transmission (e.g. implanted lenses). Sound transmission (e.g. cochlear implant).


Selection criteria for BiomaterialsFunctional performance:

Load transmission and stress distribution (e.g. bone replacement). Articulation to allow movement (e.g. artificial knee joint). Control of blood and fluid flow (e.g. artificial heart). Space filling (e.g. cosmetic surgery). Electrical stimuli (e.g. pacemaker). Light transmission (e.g. implanted lenses). Sound transmission (e.g. cochlear implant).


Selection criteria for BiomaterialsBiocompatibility Arises from differences between living and non-living materials. Bio-implants trigger inflammation or foreign body response.

Biological Compatibility Chemical Compatibility Mechanical Compatibility Nontoxic, Non-carcinogenic.

Biomaterials: Biocompatibility status-


E

E L M E MDEPENDS ON

E E E L MCOMPOSITION

E M

E M L E MOF MATERIAL

L EM


Host /Implant Factors: Which Determines bio-compatibility-

Age and health statusHost Factors:

Immunological status Metabolic status proper implantation Tissue damage Contamination and Choice of surgeon Bulk Properties: Surface Properties: Mechanical Properties: Long-term Structural Integrity:

Implant Factors:

Success of an Implant is Determined by-


Conditions of Patient. Surgeon Technical Skills.

Biocompatibility of Implant. Mechanical Properties. Corrosion Resistance.

Precautions To Be Taken For The Patients of-


Documented Renal diseases. Cardiovascular diseases precluding elective surgery. Metabolic bone diseases. Radiation bone therapy. Patient on steroid medication. Long-term infection / Chronic infection. Pregnancy and nursing.


Contraindications Severe vascular or neurological disease Uncontrolled diabetes. Severe degenerative disease. Severely impaired renal function. Hyper-calcemia, abnormal calcium metabolism Existing acute or chronic infections, especially at the site of the operation. Inflammatory bone disease such as osteomyelitis Malignant tumors.

Patients who cannot or will not follow postoperative instruction, including individuals who abuse drugs and/or alcohol .

Evolving definitions:

Conclusion And Our Consensus:

Our Consensus :

Painless administration of a vaccine by tiny microneedles on a skin patch.

Biomaterials/ Bio-devices are of very important instrument of medical science. End-use application must be a consideration. Compatibility in one application may not be compatible for another. Material and device characteristics and properties to consider Chemical, Physical, Electrical, Toxicological, Morphological and Mechanical Conditions of tissue exposure

Conclusion And Our Consensus:

Our Consensus : Merely, we give attention to asses Biocompatibility, Functional performance and patient compliance: Those points should be assed before Implantation. We should have to be more/very careful about Absolute indication, Choice of biomaterial, Biocompatibility, Functional performance, Proper implantation and post implantation patient

VeriChip Human Implantable Microchip

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