alexa Fabrication of Hybrid Composites Consists of Poly Methyl Methacrylate and Polyvinyl Alcohol and Hydroxyapatite | OMICS International
ISSN:2090-5025
Bioceramics Development and Applications
Make the best use of Scientific Research and information from our 700+ peer reviewed, Open Access Journals that operates with the help of 50,000+ Editorial Board Members and esteemed reviewers and 1000+ Scientific associations in Medical, Clinical, Pharmaceutical, Engineering, Technology and Management Fields.
Meet Inspiring Speakers and Experts at our 3000+ Global Conferenceseries Events with over 600+ Conferences, 1200+ Symposiums and 1200+ Workshops on
Medical, Pharma, Engineering, Science, Technology and Business

Fabrication of Hybrid Composites Consists of Poly Methyl Methacrylate and Polyvinyl Alcohol and Hydroxyapatite

Viet Van Thai1, Young-Ki Min2, and Byong-Taek Lee1*

1Department of Biomedical Engineering and Materials, College of Medicine, Soonchunhyang University, Cheonan, Chungnam 330-090, Republic of Korea

2Department of Physiology, College of Medicine, Soonchunhyang University, Cheonan 330-090, Republic of Korea

*Corresponding Author:
Byong-Taek Lee
Department of Biomedical Engineering and Materials
College of Medicine, Soonchunhyang University
Cheonan, Chungnam 330-090, Republic of Korea
E-mail: [email protected]

Received date: January 14, 2011; Accepted date: February 03, 2011

Visit for more related articles at Bioceramics Development and Applications

Keywords

hydroxyapatite; PMMA; PVA; electrospinning; warm-pressing; bone plate

Introduction

Plate and screw fixation is the most popular method for rigid internal fixation of the fractured bone [6]. The first generation of bone fixation was made up stainless steel, Cr-Co and Ti alloys. Their strength stood very high pressure through the implantation. However, they were so rigid that arose some big drawbacks, such as stress shielding effect and required post-operative removal. Ceramics were not potential materials for bone fixation, because they were broken under bending stresses that the fixation plates were often suffered throughout the healing treatment. Therefore, polymer emerged as promising materials for bone fixation applications.

Polymer composite materials offered desired high strength and bone like elastic properties. For decades, a variety of polymers was proposed for bone plate application. First of all were composites constituted of carbon fiber (CF), graphite fiber (GF) and thermosetting polymer (i.e. epoxy) or thermoplastic polymers (i.e. PP, PS, PE, nylon, PEEK) [6]. Thermoplastic polymer composites can be bent and contoured at the time of surgery and implantation. Among of them, CF/PEEK composite is reportedly biocompatible [6]. Recently, Ramakishna et al. [1,3,6] developed braided CF/PEEK composite bone plate using new technique to fabricate good quality continuous bulk. However, these composites were non-resorbable materials in physiological milieu. Hence, they would not decrease stress with time of implantation. Therefore, the stress-shielding effect can not be avoided perfectly. Moreover, removal operation still was need.

To overcome this disadvantage, Tormala et al. proposed a bio-resorbable polymeric composites by reinforcing matrices with resorbable fibers (PLLA) and calcium phosphate based glass fibers [6,7]. The maximum mechanical property of resorbable materials continued to be a limitation and hence they were limited to applications where the loads are moderate (i.e. fixed rods and screws) [7].

A new hybrid composite was proposed to fabricate bone plates. PMMA and PVA were sprayed by electrospinning to fibrous mats. Fine HAp powder was dispersed in PVA mats. Subsequently, mechanical deformation of hybrid composite was manufactured by die drawing method at temperature Tm > T > Tg, where Tg is the glass transition temperature and Tm is the melting point of PMMA [7]. Concurrently, pressing was performed formation of the composites.

Materials and methods

PVA with a % hydrolyzation > 98% was purchased from Sigma-Aldrich Company. PMMA (Mw > 110, 000 g/mol) was obtained from LG Chemical Company. Nitromethane (CH3NO2, Duksan Pure Chemical Co. Ltd) and distilled water were used as solvents for dissolution of PMMA and PVA, respectively. HAp nano powder was synthesized by hydrothermal-microwave assistant method [4].

PMMA fibers, were obtained by electrospinning method, formed easily when was dissolved in nitromethane [5]. Therefore, PMMA powder was dissolved in nitromethane with 20 wt% by ultrasonic process. HAp was measured from 2 wt% to 6 wt% of PVA content. PVA and HAp powder were stirred in D. I. water simultaneously at 80 °C [2].

Single electrospun spraying was applied to form mats. The PMMA and HAp-contained PVA mats were sprayed in turn. The masses of PVA and PMMA in each electrospun layer were measured the same amount. Then, amount of multilayer electrospun mats were overlapped and were heated to temperature (T, Tm > T > Tg). When the mats and moulds reached desired temperature, they were pressed immediately and cooled in air to room temperature. PVA composites and PMMA composites were fabricated as the same method to elucidate biocompatibility.

Themorphology of mats and fracture surface of composites were observed by scanning electron microscopy. MTT assays were performed with 3 composites.

Results and discussion

Nano HAp powder was penetrated successfully in PVA electrospun mats.

In this literature, HAp content was maximized at 6wt% in PVA. HAp particle sizes were not homogeneous. Therefore, HAp particles, that these average diameter were smaller than average diameter of PVA fibers, were entered the inner of PVA fibers (Figure 1(a)). Conversely, the big HAp particles connected to the outer of PVA fibers. Specially, several HAp particles, whose diameters were sub-micron, also connected to PVA fibers (Figure 1(b)). These results demonstrated the ability to increase HAp contents in PVA electrospun mats.

bioceramics-development-applications-Electrospun-dash-ruler

Figure 1: Electrospun HAp-contained PVA (the dash ruler represents 200 nm).

Separated electrospun spraying of PMMA and PVA might make a questionable problem about the association between adjacent layers. Figure 2 showed morphology of multilayer electrospun mat. PMMA fibers were micron ones and PVA fibers were sub-micro ones. The PMMA fibers and PVA fibers made up separated layers. However, the border between PMMA and PVA layers were not observed.

bioceramics-development-applications-Morphology-electrospun-multi-mat

Figure 2: Morphology of electrospun multi-mat.

Because electrospinning method could not fabricate enough mass of mats for each time of warm-pressing, mats were overlapped to desired shape (Figure 3(a)).Morphology of fracture surface of hybrid composite exhibited multiple layers clearly (Figure 3(b)). It emerged an interrogative problem about the association of each layers. However, amount of borders in each volume of composite pattern influenced on the infiltrated rate of human fluid when it was applied on clinical operation. Hence, it became a parameter to control biodegradability of hybrid composite.

bioceramics-development-applications-Photograph-cross-section-hybrid

Figure 3: Photograph and cross-section morphology of hybrid composite.

Before going on further on in vitro and in vivo studies, MTT assays were performed 3 types of composites, such as PVA, PMMA and multilayer. The cytotoxicity of PVA, PMMA and multilayer electrospun were evaluated on fibroblast culture by MTT assay method using ELISA reading at 560 nm wave length. Figure 4 shows the cytotoxicity of electrospun patterns from dilute medium with 0%, 12.5%, 25%, 50% and 100% dilute extracted solution. According to cytotoxicity comparison of each electrospun patterns, we found that 3 types of mat show good biocompatibility, in there PVA was the best one, and then PMMA and multilayer were the similar at 100% dilute extracted solution after 3 days incubation.

bioceramics-development-applications-Cytotoxicity-electrospun-multilayer

Figure 4: Cytotoxicity of electrospun PVA, electrospun PMMA and multilayer.

Conclusions

We provoked a new design for bone fixation. The fabrication of hybrid composites was successfully. Macrostructure and microstructure of composites were investigated. MTT assays demonstrated good biocompatibility of all constituents of composites. From this, the new design was potential as bone fixed implantations. Furthermore, mechanical characteristics need to investigate more detail and adequately, such as compressive strength, bending strength, elastic modulus. Concurrently, in vitro and in vivo works would be performed.

Acknowledgment

This work was supported by National Research Foundation of Korea Grant funded by the Korean Government (NRF 2009-0092808).

References

Select your language of interest to view the total content in your interested language
Post your comment

Share This Article

Recommended Conferences

Article Usage

  • Total views: 11859
  • [From(publication date):
    December-2011 - May 22, 2018]
  • Breakdown by view type
  • HTML page views : 8024
  • PDF downloads : 3835
 

Post your comment

captcha   Reload  Can't read the image? click here to refresh

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2018-19
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri & Aquaculture Journals

Dr. Krish

[email protected]

1-702-714-7001Extn: 9040

Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001Extn: 9040

Clinical Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

Food & Nutrition Journals

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

General Science

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics & Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Materials Science Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Nursing & Health Care Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

Ann Jose

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001Extn: 9042

 
© 2008- 2018 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
Leave Your Message 24x7