Miscibility of bioerodible polyphosphazene/poly(lactide-co-glycolide) blends

Nicholas R. Krogman, Anurima Singh, Lakshmi S. Nair, Cato T. Laurencin, Harry R. Allcock

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

We have previously demonstrated the feasibility of blending bioerodible polyphosphazenes with poly(lactide-co-glycolide) (PLGA) to form versatile polymeric materials with altered bioerosion properties. These studies demonstrated the effective neutralization of the acidic degradation products of PLGA by the polyphosphazene hydrolysis products. In the present study, five new polymers of dipeptide polyphosphazenes poly(ethyl glycinato)x- (glycyl-ethyl glycinato)yphosphazene] and novel blends of these polyphosphazenes with poly(lactide-co-glycolide) (PLGA) were synthesized and fabricated. The miscibility was analyzed using differential scanning calorimetry and scanning electron microscopy. Hydrogen bonding within the blends was assessed by attenuated total reflectance infrared spectroscopy. The phosphazene component of the blend contained varying ratios of the glycyl-glycine ethyl ester to the glycine ethyl ester. Poly[(ethyl glycinato)0.5(glycine ethyl glycinato)1.5phosphazene formed completely miscible blends with PLGA (50:50) and PLGA (85:15). This is ascribed to the multiple hydrogen-bonding sites within the side groups of the polyphosphazene. The components of the blend act as plasticizers for each other because a glass transition temperature for each blend was detected at a lower temperature than for each individual polymer. A hydrolysis study showed that unblended solid poly[(ethyl glycinato)0.5(glycyl ethyl glycinato)1.5phosphazenel hydrolyzed in less than 1 week. However, the blends degraded at a slower rate than both parent polymers. This is attributed to the buffering capacity of the polyphosphazene hydrolysis products which increases the pH of the degradation media from 2.5 to 4, thereby slowing the degradation rate of PLGA.

Original languageEnglish (US)
Pages (from-to)1306-1312
Number of pages7
JournalBiomacromolecules
Volume8
Issue number4
DOIs
StatePublished - Apr 1 2007

Fingerprint

Polyglactin 910
Solubility
Amino acids
Hydrolysis
Polymers
Degradation
Esters
Hydrogen bonds
Plasticizers
Glycylglycine
Differential scanning calorimetry
Infrared spectroscopy
Dipeptides
Glycine
Scanning electron microscopy
poly(phosphazene)
polylactic acid-polyglycolic acid copolymer
Temperature

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Biomaterials
  • Polymers and Plastics
  • Materials Chemistry

Cite this

Krogman, Nicholas R. ; Singh, Anurima ; Nair, Lakshmi S. ; Laurencin, Cato T. ; Allcock, Harry R. / Miscibility of bioerodible polyphosphazene/poly(lactide-co-glycolide) blends. In: Biomacromolecules. 2007 ; Vol. 8, No. 4. pp. 1306-1312.
@article{9b90964a075b4fd1ab524f9e2beb7a0e,
title = "Miscibility of bioerodible polyphosphazene/poly(lactide-co-glycolide) blends",
abstract = "We have previously demonstrated the feasibility of blending bioerodible polyphosphazenes with poly(lactide-co-glycolide) (PLGA) to form versatile polymeric materials with altered bioerosion properties. These studies demonstrated the effective neutralization of the acidic degradation products of PLGA by the polyphosphazene hydrolysis products. In the present study, five new polymers of dipeptide polyphosphazenes poly(ethyl glycinato)x- (glycyl-ethyl glycinato)yphosphazene] and novel blends of these polyphosphazenes with poly(lactide-co-glycolide) (PLGA) were synthesized and fabricated. The miscibility was analyzed using differential scanning calorimetry and scanning electron microscopy. Hydrogen bonding within the blends was assessed by attenuated total reflectance infrared spectroscopy. The phosphazene component of the blend contained varying ratios of the glycyl-glycine ethyl ester to the glycine ethyl ester. Poly[(ethyl glycinato)0.5(glycine ethyl glycinato)1.5phosphazene formed completely miscible blends with PLGA (50:50) and PLGA (85:15). This is ascribed to the multiple hydrogen-bonding sites within the side groups of the polyphosphazene. The components of the blend act as plasticizers for each other because a glass transition temperature for each blend was detected at a lower temperature than for each individual polymer. A hydrolysis study showed that unblended solid poly[(ethyl glycinato)0.5(glycyl ethyl glycinato)1.5phosphazenel hydrolyzed in less than 1 week. However, the blends degraded at a slower rate than both parent polymers. This is attributed to the buffering capacity of the polyphosphazene hydrolysis products which increases the pH of the degradation media from 2.5 to 4, thereby slowing the degradation rate of PLGA.",
author = "Krogman, {Nicholas R.} and Anurima Singh and Nair, {Lakshmi S.} and Laurencin, {Cato T.} and Allcock, {Harry R.}",
year = "2007",
month = "4",
day = "1",
doi = "10.1021/bm061064q",
language = "English (US)",
volume = "8",
pages = "1306--1312",
journal = "Biomacromolecules",
issn = "1525-7797",
publisher = "American Chemical Society",
number = "4",

}

Miscibility of bioerodible polyphosphazene/poly(lactide-co-glycolide) blends. / Krogman, Nicholas R.; Singh, Anurima; Nair, Lakshmi S.; Laurencin, Cato T.; Allcock, Harry R.

In: Biomacromolecules, Vol. 8, No. 4, 01.04.2007, p. 1306-1312.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Miscibility of bioerodible polyphosphazene/poly(lactide-co-glycolide) blends

AU - Krogman, Nicholas R.

AU - Singh, Anurima

AU - Nair, Lakshmi S.

AU - Laurencin, Cato T.

AU - Allcock, Harry R.

PY - 2007/4/1

Y1 - 2007/4/1

N2 - We have previously demonstrated the feasibility of blending bioerodible polyphosphazenes with poly(lactide-co-glycolide) (PLGA) to form versatile polymeric materials with altered bioerosion properties. These studies demonstrated the effective neutralization of the acidic degradation products of PLGA by the polyphosphazene hydrolysis products. In the present study, five new polymers of dipeptide polyphosphazenes poly(ethyl glycinato)x- (glycyl-ethyl glycinato)yphosphazene] and novel blends of these polyphosphazenes with poly(lactide-co-glycolide) (PLGA) were synthesized and fabricated. The miscibility was analyzed using differential scanning calorimetry and scanning electron microscopy. Hydrogen bonding within the blends was assessed by attenuated total reflectance infrared spectroscopy. The phosphazene component of the blend contained varying ratios of the glycyl-glycine ethyl ester to the glycine ethyl ester. Poly[(ethyl glycinato)0.5(glycine ethyl glycinato)1.5phosphazene formed completely miscible blends with PLGA (50:50) and PLGA (85:15). This is ascribed to the multiple hydrogen-bonding sites within the side groups of the polyphosphazene. The components of the blend act as plasticizers for each other because a glass transition temperature for each blend was detected at a lower temperature than for each individual polymer. A hydrolysis study showed that unblended solid poly[(ethyl glycinato)0.5(glycyl ethyl glycinato)1.5phosphazenel hydrolyzed in less than 1 week. However, the blends degraded at a slower rate than both parent polymers. This is attributed to the buffering capacity of the polyphosphazene hydrolysis products which increases the pH of the degradation media from 2.5 to 4, thereby slowing the degradation rate of PLGA.

AB - We have previously demonstrated the feasibility of blending bioerodible polyphosphazenes with poly(lactide-co-glycolide) (PLGA) to form versatile polymeric materials with altered bioerosion properties. These studies demonstrated the effective neutralization of the acidic degradation products of PLGA by the polyphosphazene hydrolysis products. In the present study, five new polymers of dipeptide polyphosphazenes poly(ethyl glycinato)x- (glycyl-ethyl glycinato)yphosphazene] and novel blends of these polyphosphazenes with poly(lactide-co-glycolide) (PLGA) were synthesized and fabricated. The miscibility was analyzed using differential scanning calorimetry and scanning electron microscopy. Hydrogen bonding within the blends was assessed by attenuated total reflectance infrared spectroscopy. The phosphazene component of the blend contained varying ratios of the glycyl-glycine ethyl ester to the glycine ethyl ester. Poly[(ethyl glycinato)0.5(glycine ethyl glycinato)1.5phosphazene formed completely miscible blends with PLGA (50:50) and PLGA (85:15). This is ascribed to the multiple hydrogen-bonding sites within the side groups of the polyphosphazene. The components of the blend act as plasticizers for each other because a glass transition temperature for each blend was detected at a lower temperature than for each individual polymer. A hydrolysis study showed that unblended solid poly[(ethyl glycinato)0.5(glycyl ethyl glycinato)1.5phosphazenel hydrolyzed in less than 1 week. However, the blends degraded at a slower rate than both parent polymers. This is attributed to the buffering capacity of the polyphosphazene hydrolysis products which increases the pH of the degradation media from 2.5 to 4, thereby slowing the degradation rate of PLGA.

UR - http://www.scopus.com/inward/record.url?scp=34247614906&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34247614906&partnerID=8YFLogxK

U2 - 10.1021/bm061064q

DO - 10.1021/bm061064q

M3 - Article

C2 - 17338563

AN - SCOPUS:34247614906

VL - 8

SP - 1306

EP - 1312

JO - Biomacromolecules

JF - Biomacromolecules

SN - 1525-7797

IS - 4

ER -