Substituted Apatite/Poly-Epsiloncaprolactone Biocomposite As Substrates And Coating On Alphatricalcium Phosphate Foams
In this research, carbonate and silicon-substituted apatite/poly-ɛ-caprolactone biocomposite were produced to be used as a porous biocomposite bone substitute. Carbonate apatite/poly-ɛ-caproplactone (CO3Ap/PCL) was also used to coat on a fully interconnected structure of α-tricalcium phosphate (α...
| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2013
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| Subjects: | |
| Online Access: | http://eprints.usm.my/36922/1/LE_THI_BANG_24_Pages.pdf |
| _version_ | 1825833563089534976 |
|---|---|
| author | Lee, Thi Bang |
| author_facet | Lee, Thi Bang |
| author_sort | Lee, Thi Bang |
| collection | USM |
| description | In this research, carbonate and silicon-substituted apatite/poly-ɛ-caprolactone
biocomposite were produced to be used as a porous biocomposite bone substitute.
Carbonate apatite/poly-ɛ-caproplactone (CO3Ap/PCL) was also used to coat on a
fully interconnected structure of α-tricalcium phosphate (α-TCP) foam to enhance the
mechanical and biological properties, and to mimic the structure of cancellous bone.
Carbonate apatite (CO3Ap) and silicon-substituted carbonate apatite (Si-CO3Ap)
were synthesized by a precipitation method. The results revealed that the silicate and
carbonate ions competed to occupy the phosphate site and also entered
simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced
the powder crystallinity and promoted ion release which resulted in a better solubility
compared to that of Si-free CO3Ap. The silicon and carbonate co-substitution
appeared to have a better effect on the early stages of osteoblast behavior (cell
attachment and proliferation) rather than the immediate/late stages (proliferation and
differentiation). The fabrication of a biocomposite derived from an interconnected
porous Si-CO3Ap reinforced with molten poly-ε-caprolactone (PCL) was then
developed to mimic the composition and structure of bone coupled with enhanced
mechanical performance. Porous silicon-substituted carbonate apatite blocks were
produced using wax as a volatile agent. The interconnected porous Si-CO3Ap
obtained has a porosity of about 80% and a pore size of about 100-200 μm. The PCL
covered, and penetrated into the pores of, the porous Si-CO3Ap to form an excellent
bonding with Si-CO3Ap leading to a significant increase in diametral tensile strength
xxi
from 0.23 MPa to a maximum of 2.04 MPa. However, although the porous
biocomposite meets the requirement of biological bone to some extent, it remains a
great challenge to make the ideal bone substitute materials that mimic the natural
structures, in which, a fully interconnected structure should be highly considered.
The mechanical behavior, microstructure and cell responses of CO3Ap/ PCL coated
α-tricalcium phosphate (α-TCP) foams were studied as an initial step for the
fabrication of a cancellous-type artificial bone replacement. The α-TCP foam was
obtained by sintering CaCO3 and CaHPO4•2H2O at 1500oC. It was then coated with
CO3Ap/PCL and its three dimensional, fully-interconnected porous structure was
found to be maintained. CO3Ap/PCL coating on α-TCP foam was proven to be very
effective in increasing the mechanical strength by 25 times and toughening the α-
TCP foam, in addition to excellent biocompatibility as proven by bone marrow cell
studies. The coated α-TCP specimens exhibited high porosity (80-85%) with large
pore size (500-700μm) that mimic the cancellous bone structure. The in vitro
biological evaluations indicated that CO3Ap/PCL used for coating improved cellular
attachment, accelerated proliferation and resulting in a greater alkaline phosphatase
(ALP) activity of both MC3T3-E1 cell-like and rat bone marrow cells. |
| first_indexed | 2024-03-06T15:09:42Z |
| format | Thesis |
| id | usm.eprints-36922 |
| institution | Universiti Sains Malaysia |
| language | English |
| last_indexed | 2024-03-06T15:09:42Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | usm.eprints-369222019-04-12T05:26:19Z http://eprints.usm.my/36922/ Substituted Apatite/Poly-Epsiloncaprolactone Biocomposite As Substrates And Coating On Alphatricalcium Phosphate Foams Lee, Thi Bang TA404 Composite materials In this research, carbonate and silicon-substituted apatite/poly-ɛ-caprolactone biocomposite were produced to be used as a porous biocomposite bone substitute. Carbonate apatite/poly-ɛ-caproplactone (CO3Ap/PCL) was also used to coat on a fully interconnected structure of α-tricalcium phosphate (α-TCP) foam to enhance the mechanical and biological properties, and to mimic the structure of cancellous bone. Carbonate apatite (CO3Ap) and silicon-substituted carbonate apatite (Si-CO3Ap) were synthesized by a precipitation method. The results revealed that the silicate and carbonate ions competed to occupy the phosphate site and also entered simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The silicon and carbonate co-substitution appeared to have a better effect on the early stages of osteoblast behavior (cell attachment and proliferation) rather than the immediate/late stages (proliferation and differentiation). The fabrication of a biocomposite derived from an interconnected porous Si-CO3Ap reinforced with molten poly-ε-caprolactone (PCL) was then developed to mimic the composition and structure of bone coupled with enhanced mechanical performance. Porous silicon-substituted carbonate apatite blocks were produced using wax as a volatile agent. The interconnected porous Si-CO3Ap obtained has a porosity of about 80% and a pore size of about 100-200 μm. The PCL covered, and penetrated into the pores of, the porous Si-CO3Ap to form an excellent bonding with Si-CO3Ap leading to a significant increase in diametral tensile strength xxi from 0.23 MPa to a maximum of 2.04 MPa. However, although the porous biocomposite meets the requirement of biological bone to some extent, it remains a great challenge to make the ideal bone substitute materials that mimic the natural structures, in which, a fully interconnected structure should be highly considered. The mechanical behavior, microstructure and cell responses of CO3Ap/ PCL coated α-tricalcium phosphate (α-TCP) foams were studied as an initial step for the fabrication of a cancellous-type artificial bone replacement. The α-TCP foam was obtained by sintering CaCO3 and CaHPO4•2H2O at 1500oC. It was then coated with CO3Ap/PCL and its three dimensional, fully-interconnected porous structure was found to be maintained. CO3Ap/PCL coating on α-TCP foam was proven to be very effective in increasing the mechanical strength by 25 times and toughening the α- TCP foam, in addition to excellent biocompatibility as proven by bone marrow cell studies. The coated α-TCP specimens exhibited high porosity (80-85%) with large pore size (500-700μm) that mimic the cancellous bone structure. The in vitro biological evaluations indicated that CO3Ap/PCL used for coating improved cellular attachment, accelerated proliferation and resulting in a greater alkaline phosphatase (ALP) activity of both MC3T3-E1 cell-like and rat bone marrow cells. 2013 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/36922/1/LE_THI_BANG_24_Pages.pdf Lee, Thi Bang (2013) Substituted Apatite/Poly-Epsiloncaprolactone Biocomposite As Substrates And Coating On Alphatricalcium Phosphate Foams. PhD thesis, Universiti Sains Malaysia. |
| spellingShingle | TA404 Composite materials Lee, Thi Bang Substituted Apatite/Poly-Epsiloncaprolactone Biocomposite As Substrates And Coating On Alphatricalcium Phosphate Foams |
| title | Substituted Apatite/Poly-Epsiloncaprolactone
Biocomposite As Substrates And Coating On Alphatricalcium
Phosphate Foams
|
| title_full | Substituted Apatite/Poly-Epsiloncaprolactone
Biocomposite As Substrates And Coating On Alphatricalcium
Phosphate Foams
|
| title_fullStr | Substituted Apatite/Poly-Epsiloncaprolactone
Biocomposite As Substrates And Coating On Alphatricalcium
Phosphate Foams
|
| title_full_unstemmed | Substituted Apatite/Poly-Epsiloncaprolactone
Biocomposite As Substrates And Coating On Alphatricalcium
Phosphate Foams
|
| title_short | Substituted Apatite/Poly-Epsiloncaprolactone
Biocomposite As Substrates And Coating On Alphatricalcium
Phosphate Foams
|
| title_sort | substituted apatite poly epsiloncaprolactone biocomposite as substrates and coating on alphatricalcium phosphate foams |
| topic | TA404 Composite materials |
| url | http://eprints.usm.my/36922/1/LE_THI_BANG_24_Pages.pdf |
| work_keys_str_mv | AT leethibang substitutedapatitepolyepsiloncaprolactonebiocompositeassubstratesandcoatingonalphatricalciumphosphatefoams |