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Properties of Biomaterials
426308 Ceramic Eng. Prop.
Asst. Prof. Dr. Sirirat T. Rattanachan
2
Content (3 �������)
• Definition
• Application
• The responding of tissue to implants
• Biomaterials and design
• In vitro and In vivo
3
Definitions
• A biomaterial is a nonviable material used in a medical device, intended to interact with biological systems. (Williams, 1987)
• Biocompatibility is the ability of a material to perform with an appropriate host response in a specific application. (Williams, 1987)
4
Biomaterials market
5
6
7
Applications
� ก����ก�������� ���� ก � (Skeletal systems)
���������ก��� ������ :Ti, Ti-Al-V
alloys, stainless steel, polyethylene
������ �������ก����ก : stainless
steel, Co-Cr alloys
�������ก����ก : Poly (methyl
methacrylate)
�������ก����ก: Hydroxyapatite
��������� �!�: Teflon, Dacron
��ก"#�� �!� : Ti, Al, calcium
phosphate
"#�� �!� : porcelain, zirconia
� ก����ก�������� ���� ก � (Skeletal systems)
���������ก��� ������ :Ti, Ti-Al-V
alloys, stainless steel, polyethylene
������ �������ก����ก : stainless
steel, Co-Cr alloys
�������ก����ก : Poly (methyl
methacrylate)
�������ก����ก: Hydroxyapatite
��������� �!�: Teflon, Dacron
��ก"#�� �!� : Ti, Al, calcium
phosphate
"#�� �!� : porcelain, zirconia Ref. 2
8
9
� ����ก ����������������� (Cardiovascular systems)
���������: Dacron, Teflon, polyurethane
�$%� ��&'� �!�: stainless steel, carbon
�()ก�*�&�ก����+��������� : silicone rubber, Teflon, polyurethane
� ����ก ����������������� (Cardiovascular systems)
���������: Dacron, Teflon, polyurethane
�$%� ��&'� �!�: stainless steel, carbon
�()ก�*�&�ก����+��������� : silicone rubber, Teflon, polyurethane
Ref. 2
Applications
10
� ���� (organs)
��� �����: Polyurethane
�������������:silicone-collagen composite
������: cellulose, polyacrylonitrile
ก������������� ���� !: silicone rubber
�� �������� (organs)(organs)
��� �����: Polyurethane
�������������:silicone-collagen composite
������: cellulose, polyacrylonitrile
ก������������� ���� !: silicone rubber
Applications
11
� ������������ก������� (Senses)
ก����ก ���%�&� (Cochlear): Platinum electrode
�������� �!� (Intraocular lens): poly(methylmethacrylate), silicone rubber, hydrogel
,��� ,�� ����� (contact lens):silicone-acrylate, hydrogel
�����ก���� ก��'ก�� (Corneal bandage): collagen, hydrogel
� ������������ก������� (Senses)
ก����ก ���%�&� (Cochlear): Platinum electrode
�������� �!� (Intraocular lens): poly(methylmethacrylate), silicone rubber, hydrogel
,��� ,�� ����� (contact lens):silicone-acrylate, hydrogel
�����ก���� ก��'ก�� (Corneal bandage): collagen, hydrogel
Ref. 2
Applications
12
Tissue Response to Implants
• Interactions between implant surface and tissue
implant
waterDissolved ions
Free bimolecular
Chemotaxis ก����������� ��������ก�����
Phagocytosis ��ก��ก�����������������ก���
Macrophage activation ������������������ �ก��������ก���
13
Chemotaxis
Target
Macrophages
Macrophages activation
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The response of hard tissue to implantation
15
Scheme of process of wound healing in a simple incisional wound
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Scheme of process of wound healing in the presence of a foreign body
�������!"���"�"�
17
Sequence of surface reaction in the bioactive bonding to bone
Bioactive glass (SiO2-CaO-Na2O)Bioactive glass (SiO2-CaO-Na2O)
�ก�"# $� SiOH bond
Polycondensation of SiOH+SiOH�Si-O-Si
Adsorption of amorphous Ca+PO4+CO3
Crystallization of Hydroxyl carbonate apatite (HCA)
Adsorption of biological moities in HCA layerAction of macrophagesAttachment of stem cells
Differentiation of stem cells ���!��������%���&������'#�����Generation of matrix
Crystallization of matrix
deve
lopm
ent
Bone growth
18
Factors affecting implant-tissue interfacial response
• (�" �� �"�)*�+
•�,� �� �"�)*�+
•�,����-��� �- �
•.�����������-��� �- �
•����#�����-��
• �/�ก���������������-��
• ก���(����% ก�������
•��������ก�����
•(�" ���0����
• �������1�2� ���0����
• ��� ���0����
•��������������"+��0����
•��������������"���-��� �- �
• ก�������3������ก�" 40���-��� �- �
• ก���(����%�����
• ��������ก�����
Implant sideTissue side
19
Various methods of prosthesis fixation
20
Bioceramics• Alumina• Zirconia• Calcium phosphate• Hydroxyapatite• Bioactive glasses• Bioactive glass-ceramics
21
�������ก���ก����ก
22
Bone tissue
• Schematic drawings of bone tissue. On the left is a depiction of the 3 types of lamellar bone in the shaft of a long bone. The Haversian systems, and inner and outer lamella are shown. On the right, is a higher magnification diagram of a Haversian canal and contiguous lamella. Taken from Junqueira and Carneiro, Basic Histology, a text and atlas, pp. 44 and 46, Figures 8-6 and 8-8.
23
Physical properties of materials used for joint prosthesis and bone
24
(�" �� �"����ก�������%��0����
• � �"���&#�5 � ��0���������2��� �"����
• � �"�3�%��&#�5����6� Bioinert � �ก�" Fibrous tissue
• � �"�3�%��&#�5����6� Bioactive � �ก�"ก���(����%ก ���0����
• � �"�3�%��&#�5����6� Biodegradable � ��ก���������������"�����0�������$���(���3"�
25
Types of Tissue attachment of bioceramic prostheses
Tricalcium phosphate
Bioactive glasses
Replacement with tissueResorbable
Bioactive glasses, Bioactive glass-ceramics HA
Interfacial bonding with tissues (bioactive fixation)
Bioactive
Hydroxyapatite (HA),
HA coated porous metals
Ingrowth of tissues into pores
(biological fixation)
Porous
Al2O3, ZirconiaMechanical interlock
(morphological fixation)
Nearly inert
ExampleType of attachmentType of implant
26
Bioinert
����� ���&� �"�)*�+ ��.#ก����� ���,*�����
�"����������ก �.������#�������� ����%ก���4ก��"���ก
• Alumina
• Zirconia ��& Y-TZP, Mg-PSZ
27
Alumina for surgical implants
• High density, purity (>99.5% Al2O3) is used in load-bearing hip protheses and dental implants – Excellent corrosion resistance
– Good compatibility
– High wear resistance
– High strength
28
Use of zirconia in surgical implants
• Tetragonal zirconia stabilized with yttria (TZP)
• Magnesium oxide partially stabilized zirconia (MG-PCZ)
• High fracture toughness
• High flexural strength
• Lower young’s modulus
29
Bioactive glass
• Bioglass® 45S5: 45%SiO2, 24.5 Na2O, 24.4% CaO and 6%P2O5� melt at 1300-1450ºC
• Na2O-CaO-SiO2 glass ����"��� P2O5, B2O3 ��� CaF2• Their rapid rate of surface reaction� leads to fast tissue bonding
• Mechanical weakness and low fracture toughness
• Application: middle ear device
30
Bioactive glass-ceramics
• Apatite-wollastonite (A/W) glass ceramics: 3CaO.P2O5-CaO.SiO2-
MgO.CaO.2SiO2� fine grained
oxyapatite and fibrous β-wollastoniteprecipitated.
31
Mechineable and phosphate glass-ceramics
• BIOVERIT I and BIOVERIT II: a mica-apatite glass-ceramics (SiO2-(Al2O3)-MgO-Na2O-K2O-F-CaO-P2O5 base glass system.
• Clinical applications: Orthopaedic surgery (spacers), head and neck surgery (middle ear implants), stomatology (tooth root and veneer laminates)
32
Calcium phosphate ceramics
• ������ก���������� ��ก 3"�"�ก �ก��"1ก���,*��5��
• ��������ก�����������ก���� ."���� "�%� Ca/P = 0.5 -2.0
• Dicalcium phosphate dihydrate (DCPD) or Brushite �
CaHPO4.2H2O (Ca/P = 1.0)
• Dicalcium phosphate (montite) CaHPO4
• Tricalcium phosphate (Ca3(PO4)2) Ca/P = 1.5
• Tetracalcium phosphate (Ca4O(PO4)2) Ca/P = 2.0
• Hydroxyapatite Ca/P = 1.67
• Octacalcium phosphate (Ca8H2(PO4)6.5H2O)
Ca/P = 1.33
33
Apatite
Hydroxyapatite (Ca10(PO4)6(OH)2)
34
Forms and application
• Dense hydroxyapatite
• Porous hydroxyapatite
• Coating
35
Synthetic hydroxyapatite
Ca10(PO4)6(OH)2 or HA
(Ca,X)10(PO4,HPO4,CO3)6(OH,Y)2X= Mg, Na, Sr = cation
Y = choride or fluoride = anion
Sintered HA
Porous sHA
• �������� ����� ��ก calcium nitrate,
Diammonium hydrogen phosphate
And NH4OH • ก����ก��� ���� ��ก���� �����ก��
36
37
��� �� ����� ���!����ก"��#�$
• ��� �����ก� 3"��ก% bending strength, flexure testing, Fracture toughness, hardness
• ��� �����-�� 3"��ก% surface charge, hydrophilicity or hydrophobicity� surface analysis and solution
analysis
• ��� ��"������� ��ก 3"�ก ��%��ก�� Bioactive and Biocompatability
38
Bioactivity and biocompatibility
• Bioactivity: ���ก���"����� in vivo – 74ก5� ���ก���(����% �ก��"1กก �� �"�)*�+ ����� !�����������
��8���+ก���4"�ก��ก �ก��"1ก– � ��%�� Bioactive glass �� 42-53 %SiO2 �4�����(����%
ก �ก��"1ก3"�6��+ 1 � �%� Bioactive glass ����� 54-60%SiO2 ���(����%ก �ก��"1ก3"�6��+ 2 � �"���
– ก��74ก5�#A��ก��� �� �"������(%+�������������ก�������� pH (7.2-7.4) �����ก � �����+�%��ก����5��
– Bioactive glass +�������� SBF ."�ก��"1"� �.������ก �������������( 0.�����������-�� �(%�ก�" HCA
39
• Biocompatibility: ��"���"#�"�$����$ก�%��$!&'(� � ���ก�!ก���%$������"#�"����)��%*��$!&'(� ���#� – In vitro � +�ก���!$%ก���%$��������, ������$����-.�%.&��!/ ���� +�
ก���!$%�%"#��/�ก�������ก��01ก2� �$���������� �!ก����%����������,�������������$�%)�3, ก��1!�ก��������,%�4"#������$!&�1#�)�ก�%.���� +���1ก���.������%�������$!&
– In vivo �!$% �$���������� $���,�!�����!��5ก�����ก�%ก��01ก2�ก������ก��!)ก������ก $���$���, �6��������ก�%ก��01ก2�ก������ก��!)ก���ก��$�/��ก��!)ก�1#� ���
– Histomorphometry � +�ก��01ก2� ����3��ก��!)ก����ก�!�1#� ������������7� ���$!&'(� �
Bioactivity and biocompatibility
40
Consequences of Implant-Tissue interaction
Tissue replaces implantDissolution of implant
Tissue forms an interfacial bond with the implant
Bioactive
Tissue forms a non-adherent fibrous capsule around the implant
Biologically nearly inert
Tissue diesToxic
ConsequenceImplant-tissue reaction
41
Biodegradable
'(�-ก���+��+ก����ก
����(���(� ��� scaffold = cell + biomaterials
Inorganic compounds: HA, bioactive glass
Biopolymers: PMMA, PE
Biodegradable polymer: aliphatic polyesters=
42
Bioactive polymer/ceramic composite scaffold
Bioactive ceramic phase
(bioglass©, HA)
Biodegradable and bioactive composites
Biodegradable polymer
(PDLLA, PHA, PLGA, collagen)
Bioactive phase
as filler or coating
Dense compositesPorous composites
43
Tissue engineering
scaffold
����-��$ �+ก����+��+��!+�
.�& ���������ก�� �$��'.��������)���!��)/������ก����ก���!�������0���)/�$1
0�� .�& ��ก$�ก����ก��- ����ก��0����ก�-���+ก�!
��-& ���������ก�������2�3%���)�-- ����-����0��
ก����-���+����������
ก��& ��ก$�ก������+���%��!���������������4�!&�
44
In Vitro Testing of Cytotoxicity of Materials
• Cellular mechanisms of toxicity can be described using biochemical assays
• Valid alternatives to animal models are needed.
45
ก�����0��������� �"�� ��%���!���%&� Osteoblasts ���'���!���(& alpha minimum essential medium
Scaffold ���(&��&%���)���ก*��+(& culture medium 3 h, 37oC
5%CO2 and 95% air
�!�����,���'������&-���� scaffold �.�&�&��,)&�&�&����,�& medium ��ก/ 2 ��&
�+�� ��!���)��&��.�&�&�!�����,�ก�� = �.�&�&�!������,� +& – �.�&�&�!�����,�+����ก�� 2��("+ hemacytometer
ก�� ��� �ก���$�,��.�&�& �.���+2��("+ fluorescence #��( +ก���+�� �
46
Indirect contact (In vitro testing)
Reagent control Negative control
Positive control Sample
47
Direct contact
Reagent control Negative control
Positive controlSample
48
Standards for testing cytotoxicity
• ISO technical committee (international)
• CEN technical committee (European)
• ISO 10993
49
In vivo����ก����� ���+ ��$� ��!( �5
������ 6#+����(
���%!+�)/���!����� 2-4 ��)�� �
��������ก�� ���+�����! SEM, TEM
50
SEM micrographs (a and c) and toluidine blue-stained (b and d) thin sections (after glass removal and re-embedding) of H (a and b) and HZ5 (c and d) flat specimens implanted into calvaria for 30 days. (a) Several boneremnants, most showing erosion surfaces (indented contours). (b) A great (multinucleated) osteoclast (arrow)eroding the bone beneath of the glass (H). (c) New bone (arrow) formed in apposition to the bone spared byosteoclasts; note also that much bone has been resorbed (below and on the left of the arrow). (d) Active osteoblasts(arrows) forming new bone in apposition to the pre-existing bone inside the fibrous tissue separating the bone fromthe HZ5 glass
51
Biomaterials science ���ก����ก�--0)�����$�4�*:�
Ref. 2
52
Bioceramics
53
Form, phase and function of bioceramics
Replacement and augmentation of tissue,
Replace functioning parts
Single crystal
Polycrystalline
Glass
Glass-ceramic
Composite (multi-phase)
Bulk
Tissue bonding,
corrosion protection
Polycrystalline
Glass
Glass-Ceramic
Coating
Space-filling, therapeutic treatment,
Regeneration of tissues
Polycrystalline
Glass
Powder
FunctionPhaseForm
54
Any questions?