Degradable polyphosphazene/poly(α-hydroxyester) blends: Degradation studies
Archel M.A. Ambrosio, Harry R. Allcock, Dhirendra S. Katti, Cato T. Laurencin
Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(α-hydroxyester) blend whose degradation products are less acidic than those of the poly(α-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14 mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.
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poly(phosphazene) Medicine & Life Sciences 100%
Degradation Product Chemical Compounds 51%
Polymers Medicine & Life Sciences 48%
Degradation Engineering & Materials Science 37%
Biomaterial Chemical Compounds 23%
Polyglactin 910 Medicine & Life Sciences 17%
Glycolic Acid Chemical Compounds 17%
pH Value Chemical Compounds 17%
Ambrosio, A. M. A., Allcock, H. R., Katti, D. S., & Laurencin, C. T. (2002). Degradable polyphosphazene/poly(α-hydroxyester) blends: Degradation studies. Biomaterials, 23(7), 1667-1672. https://doi.org/10.1016/S0142-9612(01)00293-9
Ambrosio, Archel M.A. ; Allcock, Harry R. ; Katti, Dhirendra S. ; Laurencin, Cato T. / Degradable polyphosphazene/poly(α-hydroxyester) blends : Degradation studies. In: Biomaterials. 2002 ; Vol. 23, No. 7. pp. 1667-1672.
@article{077944b194974be08c23d84d05910ae9,
title = "Degradable polyphosphazene/poly(α-hydroxyester) blends: Degradation studies",
abstract = "Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(α-hydroxyester) blend whose degradation products are less acidic than those of the poly(α-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14 mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.",
author = "Ambrosio, {Archel M.A.} and Allcock, {Harry R.} and Katti, {Dhirendra S.} and Laurencin, {Cato T.}",
note = "Funding Information: This work was supported by the NSF Grant BE59817872. (Presidential Faculty Fellow Award.)",
journal = "Biomaterials",
Ambrosio, AMA, Allcock, HR, Katti, DS & Laurencin, CT 2002, 'Degradable polyphosphazene/poly(α-hydroxyester) blends: Degradation studies', Biomaterials, vol. 23, no. 7, pp. 1667-1672. https://doi.org/10.1016/S0142-9612(01)00293-9
Degradable polyphosphazene/poly(α-hydroxyester) blends : Degradation studies. / Ambrosio, Archel M.A.; Allcock, Harry R.; Katti, Dhirendra S.; Laurencin, Cato T.
In: Biomaterials, Vol. 23, No. 7, 01.04.2002, p. 1667-1672.
T1 - Degradable polyphosphazene/poly(α-hydroxyester) blends
T2 - Degradation studies
AU - Ambrosio, Archel M.A.
AU - Allcock, Harry R.
AU - Katti, Dhirendra S.
AU - Laurencin, Cato T.
N1 - Funding Information: This work was supported by the NSF Grant BE59817872. (Presidential Faculty Fellow Award.)
N2 - Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(α-hydroxyester) blend whose degradation products are less acidic than those of the poly(α-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14 mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.
AB - Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(α-hydroxyester) blend whose degradation products are less acidic than those of the poly(α-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14 mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.
JO - Biomaterials
JF - Biomaterials
Ambrosio AMA, Allcock HR, Katti DS, Laurencin CT. Degradable polyphosphazene/poly(α-hydroxyester) blends: Degradation studies. Biomaterials. 2002 Apr 1;23(7):1667-1672. https://doi.org/10.1016/S0142-9612(01)00293-9