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The Properties of Polyurethanes Based on Synthetic Polyhydroxybutyrate for Medical Application

Brzeska J., Janik H., Kowalczuk M., Rutkowska M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

2012

nr 74

5--14

Polyurethanes belong to materials commonly used in many different fields of our life. Very important part of their application is using as biomaterial. But their properties have to be appropriate for contact with living organisms. Using in synthesis of polyurethanes the synthetic analog of natural polyhydroxybutyrate - telechelic atactic poly[(R,S)-3-hydroxybutyrate] (a-PHB) could make them more biocompatible. The investigated polyurethanes were synthesized with aliphatic and aromatic diisocyanate. Their soft segments were built with polycaprolactone and a-PHB. The physical, mechanical, thermal properties and degradability of obtained polyurethanes were estimated. The polyurethane samples were also checked for medical application. After the extraction in hexane and sterilization their influence on blood parameters and on pathogenic microorganisms were estimated. The obtained polyurethanes were amorphous and hydrophilic but the amount of absorbed water was small and is on the same level for both materials. Sterilization of aliphatic polyurethane samples insignificantly changed the mechanical properties whereas aromatic polyurethane seemed to be more sensitive to conditions of sterilization. The results of polyurethane degradation indicated higher influence of oxidative than hydrolytic mechanism. The presence of aliphatic polyurethane decreased the growth of some pathogenic microorganisms. Both kinds of polymers did not change the parameters of whole blood. In conclusion it could be stated that aliphatic polyurethane based on atactic poly[(R,S)-3-hydroxybutyrate] displayed the properties appropriate for further investigations for medical application without the risk of generation the cancerogenic degradation products which could be formed from polyurethane obtained with aromatic diisocyanate.

Właściwości poliuretanów z syntetycznym poli([R,S]-3- Hydroksymaślanem) w segmencie giętkim

Brzeska J., Dacko P., Janeczek H., Kowalczuk M., Janik H., Rutkowska M.

Czasopismo Techniczne. Mechanika

2009

R. 106, z. 1-M

37-41

Celem pracy było otrzymanie poliuretanów (PUR), zawierających PCL lub PTMG oraz ataktyczny, telecheliczny poli([R,S]-3-hydroksymaślan) (a-PHB) w segmencie giętkim, o potencjalnym zastosowaniu do celów medycznych. Poprzez zbadanie właściwości termicznych (DSC), mechanicznych (wytrzymałości na rozciąganie i twardości) oraz gęstości otrzymanych poliuretanów oznaczono wpływ wprowadzenia a-PHB do budowy segmentów giętkich tych polimerów. Obecność a-PHB w segmentach giętkich poliuretanów obniżyła ich wytrzymałość na rozciąganie i zwiększyła nieco gęstość. Jednocześnie podwyższyła temperatury zeszklenia (widoczne zwłaszcza dla PUR z PCL) i obniżyła krystaliczność segmentów giętkich PUR z PTMG. Może to pozytywnie wpłynąć na degradowalność poliuretanów w organizmie żywym.

The aim of the present study was obtaining the new polyurethanes with PCL or PTMG and atactic, telechelic poly([R,S]-3-hydroxybutyrate) (a-PHB) in soft segment, for medicine. Influence of introducing of a-PHB into the soft segments on properties of polyurethanes was estimated by measuring thermal (DSC) and mechanical (hardness, tensile strength) properties and density of those polymers. It was concluded that presence of a-PHB in soft segment had caused decreasing of tensile strength and increasing of density of obtained polyurethanes. Reduction of crystallinity of soft segments in polyurethane with PTMG would enhance probably degradability of that polymer in living organisms.