The influence of side group modification in polyphosphazenes on hydrolysis and cell adhesion of blends with PLGA.
Polyphosphazenes have been synthesized with tris(hydroxymethyl)amino methane (THAM) side groups and with co-substituents glycine ethyl ester and alanine ethyl ester. The THAM side group was linked to the polyphosphazene backbone via the amino function. The three pendent hydroxyl functions on each THAM side group were utilized for hydrogen bonding association with poly(glycolic-lactic acid) (PLGA). Co-substitution of the polyphosphazene with both THAM and glycine or alanine ethyl esters was employed to avoid the insolubility of the single-substituent THAM-substituted polyphosphazenes. Both poly[(tris(hydroxymethyl)aminomethane)(ethyl glycinato)phosphazene] and poly[(tris(hydroxymethyl)aminomethane)(ethyl alanato)phosphazene] (1:1 ratio of side groups) were blended with PLGA (50:50) or PLGA (85:15). DSC analysis indicated miscible blend formation, irrespective of the detailed molecular structure of the polyphosphazene or the composition of PLGA in the blend. Hydrolysis studies of the polyphosphazene:PLGA (50:50) blends indicated that the PLGA component hydrolyzed more rapidly than the polyphosphazene. Primary osteoblast cell studies showed good cell adhesion to the polymer blends during 14 days, but subsequent limited cell spreading due to increased surface roughness as the two polymers eroded at different rates.
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
Nicholas R
NR
Krogman
Arlin L
AL
Weikel
Katherine A
KA
Kristhart
Syam P
SP
Nukavarapu
Meng
M
Deng
Lakshmi S
LS
Nair
Cato T
CT
Laurencin
Harry R
HR
Allcock
D000818:Animals; D000831:Animals, Newborn; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D002152:Calorimetry, Differential Scanning; D002448:Cell Adhesion; D002478:Cells, Cultured; D005562:Formazans / Q000378:metabolism; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry* / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D011100:Polyglycolic Acid / Q000737:chemistry / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000166:cytology; D012995:Solubility; D013696:Temperature; D013778:Tetrazolium Salts / Q000378:metabolism; D013997:Time Factors; D014867:Water / Q000737:chemistry
D001672:Biocompatible Materials; D005562:Formazans; D009943:Organophosphorus Compounds; D011108:Polymers; D013778:Tetrazolium Salts; C108974:poly(phosphazene); D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C079782:MTT formazan; D011100:Polyglycolic Acid; D019344:Lactic Acid