Soutenance mémoire
The field of biomaterials include medical devices has turn into an electrifying area because these materials improve the quality and longevity of human life. The first and foremost necessity for the selection of the biomaterial is the acceptability by human body; so biocompatibility [1].
Medical devices
The term “medical devices” includes everything from highly sophisticated computerizedmedical equipment down to simple wooden tongue depressors. The intended primarymode of action of a medical device on the human body, in contrast with that of medicinalproducts, is not metabolic, immunological, or pharmacological[2]. Several different international classification systems for medical devices are still in usein the world today. The World Health Organization, with its partners, is working towardsachieving harmonization in medical device nomenclature, which will have a significantimpact on patient safety. This is particularly important to be able toidentify adverse incident reports and recalls. The Global Harmonization Task Force has proposed the following harmonized definitionfor medical devices; “Medical device” means any instrument, apparatus, implement, machine, appliance,implant, in vitro reagent or calibrator, software, material or other similar or relatedarticle, intended by the manufacturer to be used, alone or in combination, for humanbeings for one or more of the specific purposes of:
• Diagnosis, prevention, monitoring, treatment or alleviation of disease
• Diagnosis, monitoring, treatment, alleviation of or compensation for an injury
• Investigation, replacement, modification, or support of the anatomy or of aphysiological process
• supporting or sustaining life
• Control of conception
• Disinfection of medical devices
• providing information for medical purposes by means of in vitro examination ofspecimens derived from the human body and which does not achieve its primaryintended action in or on the human body by pharmacological, immunological ormetabolic means, but which may be assisted in its function by such means.
Note: An accessory is not considered to be a medical device. However, where anaccessory is intended specifically by its manufacturer to be used together with the‘parent’ medical device to enable the medical device to achieve its intended purpose,it should be subject to the same procedures and GHTF guidance documents as applyto the medical device itself.
Note: The definition of a device for in vitro examination includes, for example,reagents, calibrators, sample collection devices, control materials, and relatedinstruments or apparatus. The information provided by such an in vitro diagnosticdevice may be for diagnostic, monitoring or compatibility purposes. In somejurisdictions, reagents and the like may be covered by separate regulations.
Note: Products, which are considered to be medical devices in some jurisdictionsbut for which there is not yet a harmonized approach, are:
• Aids for disabled/handicapped people
• Devices for the treatment/diagnosis of diseases and injuries in animals
• Spare parts for medical devices
• Devices incorporating animal and human tissues which may meet the requirementsof the above definition but be subject to different controls[2].
Biomaterials
History:
The first biomaterials used were gold and ivory for replacements of cranial defects. This was done by Egyptians and Romans. Biological materials such as placenta were used since the 1900s. Celluloid was the first man-made plastic used for cranial defects a polymethyl methacrylate (PMMA) was one of the first polymers accepted since World War II[3]. Some of the earliest biomaterial applications were as far back as ancient Phoenicia where loose teeth were bound together with gold wires for tying artificial ones to neighboring teeth[1]. In the early 1900’s bone plates were successfully implemented to stabilize bone fractures and to accelerate their healing[1]. While by the time of the 1950’s to 60’s, blood vessel replacement were in clinical trials and artificial heart valves and hip joints were in development[1].
600 B.C Samhita Nose construction
1893-1912 W.A.LaneSteel screws for fixation
1912 W.D.ShermanUse of Vanadium steel plate
1938 P.Wiles First total hip replacement
1952 A.B.VoorheesBlood Vessel
1953 A.KantrowitzIntraortic balloon pumping
1960 M.I.Edwards Heart valve
1980 W.J.Kolff Artificial Heart
Definition:
In general, a biomaterial is defined as any substance, except food and medications that can be used for a length of time as part of a system that aims to treat or to replace any tissue, organ, or body function. Few materials, if any, are totally inert from a physiological standpoint; most materials present a variety of components with potential toxic or irritating properties. In addition, chemical reactions that occur during setting of the material may also produce noxious effects [4] Biomaterials need to satisfy a number of prerequisites before that can be used in applications, including biocompatibility. To verify this feature, its components should be subjected to different tests, performed as recommended by various organizations and federations. These tests consist of a sequence of research protocols, described and regulated in many countries, for correct use of experimental materials under evaluation, thereby determining their safety for clinical application in humans [4].
Biocompatibility
definition:
Biocompatibility may be defined as:
“Ability of a biomaterial to perform its desired function with respect to a medical therapy, without eliciting any undesirable local or systemic effects in the recipient or beneficiary of that therapy, but generating the most appropriate beneficial cellular or tissue response to that specific situation, and optimizing the clinically relevant performance of that therapy [4].” Biocompatibility can also be defined as the relationship between a material and the organism so that neither produces undesirable effects. Biocompatibility has been mentioned in many works with increasing interest in evaluating the characteristics of medical and dental materials and devices and responses caused by its components. An ideal pattern for determining these properties has not yet been determined, however, various methods have been suggested for this purpose [4]. The most accepted definition of biomaterials is currently the one employed by the American National Institute of Health that describes biomaterial as ‘‘any substance or combination of substances, other than drugs, synthetic or natural in origin, which can be used for any period of time, which augments or replaces partially or totally any tissue, organ or function of the body, in order to maintain or improve the quality of life of the individual’’ [3].
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Table des matières
GENERAL INTRODUCTION
CHAPTER I: BIOMATERIALS AND BIOCOMPATIBILITY
I.1 Introduction
I.2 Medical devices
I.3 Biocomaterial
I.3.1.History
I.3.2 Definition
I.4 Biocompatibility
I.4.1 definition
I.4.2 Components of biocompatibility
I.4.3 Uses for Biomaterials
I.4.4 Types of Biomaterials
I.4.5 Biomaterials associated infection
I.5 conclusion
CHAPTER II: BIOCOMPATIBILITY TESTING
II. Methods of biocompatibility testing
II.1 Introduction
II.2 In vitro and in vivo tests
II.2.1 In vitro tests
II.2.2 Animal experiments
II.2.3 Clinical tests
II.3 Biocompatibility testing processes
II.3.1 Toxicology
II.3.2 Biocompatibility
II.3.3 Mechanical and Performance Requirements
II.3.4 Regulation
II.4 Standards for biomaterials and biocompatibility testing
II.5 Conclusion
GENERAL CONCLUSION
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