Related Experiment Videos
Evaluation of polyphosphates and polyphosphonates as degradable biomaterials
M Richards1, B I Dahiyat, D M Arm
1Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218.
Journal of Biomedical Materials Research
|September 1, 1991
Summary
Bisphenol A-based poly(phosphoesters) show promise as degradable biomaterials, exhibiting controlled degradation and minimal tissue reaction. UV sterilization proved most effective, preserving material properties for potential biomedical applications.
Area of Science:
- Polymer Science
- Biomaterials Science
- Materials Engineering
Background:
- Bisphenol A-based poly(phosphoesters) are a class of polymers being investigated for their potential as degradable biomaterials.
- Understanding their degradation behavior and biocompatibility is crucial for their application in medicine.
Purpose of the Study:
- To evaluate the degradation characteristics of bisphenol A-based poly(phosphoesters) under various conditions.
- To assess the impact of sterilization methods on polymer properties.
- To investigate the in vivo tissue response to these polymers.
Main Methods:
- In vitro and in vivo degradation studies were conducted on four different poly(phosphoesters).
- Swelling behavior and its correlation with degradation rate were analyzed.
- The effects of steam autoclave, ethylene oxide, and UV irradiation/antibiotic treatment on polymer properties were compared.
- Tissue response in rabbits was evaluated histologically.
Main Results:
- All four polymers demonstrated degradation in vitro and in vivo.
- Degradation rates were influenced by polymer side-chain structure and swelling behavior, with ethyl side-chain polymers showing higher water absorption.
- UV irradiation followed by antibiotic treatment was the optimal sterilization method, unlike steam autoclave and ethylene oxide, which altered polymer properties.
- In vivo studies in rabbits showed minimal encapsulation and inflammatory response (lymphocyte, giant cell, macrophage activity), with no signs of edema or necrosis.
- Elastic moduli ranged from 488 MPa (poly(bisphenol A-ethylphosphate), BPA/EOP) to 627 MPa (poly(bisphenol A-phenylphosphonate), BPA/PP).
- BPA/PP exhibited lower ultimate strength, modulus, and energy to failure compared to poly(L-lactic acid) (PLLA).
Conclusions:
- Bisphenol A-based poly(phosphoesters) are degradable biomaterials with tunable properties based on side-chain structure.
- UV sterilization is recommended to maintain the integrity of these polymers.
- The materials demonstrate good biocompatibility, with minimal adverse tissue reactions in vivo.
- Further research may be needed to optimize mechanical properties for specific applications, potentially through comparison with established biomaterials like PLLA.