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An injectable and biomimetic multi‐phase nanocomposite for non‐invasive bone tissue engineering: fabrication and mechanistic evaluation
Author(s) -
Gohil Shalini V.,
Kumar Neeraj
Publication year - 2017
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.4022
Subject(s) - plga , materials science , nanocomposite , glycolic acid , swelling , chemical engineering , ethylene glycol , rheology , polymer , silk , lactic acid , polymer chemistry , composite material , nanotechnology , nanoparticle , biology , bacteria , engineering , genetics
An injectable, non‐hardening nanocomposite bone graft has been developed using a combination of nanohydroxyapatite as bioactive and osseointegrative material; P‐15 peptide‐modified poly(lactic‐ co ‐glycolic acid) (PLGA) microspheres as biomimetic and osteoinductive agent; and PLGA–poly(ethylene glycol) (PEG)–PLGA as a carrier gel. Increase in lactic acid/glycolic acid ratio of PLGA–PEG–PLGA resulted in stronger gels with a wider gelation window. Addition of 2.5‐fold nanohydroxyapatite resulted in significant changes in injectability (3.5‐fold force of injection), swelling characteristics (2.5 times swelling index), rheological (shear viscosity from 2.1 × 10 1 Pa s for NC3_700 to 1.5 × 10 6 Pa s for NC3_73.52 and from 3.9 × 10 2 Pa s for NC8_700 to 3.76 × 10 6 Pa s for NC8_732; an increase in elasticity at the level of 1–1000 kPa), and thermal properties of the nanocomposites. A mechanistic study showed that nanohydroxyapatite exhibits a high degree of association with the gel and interferes with its gelation owing to changes in hydrogen bonding interactions between C=⃥O of polymer chains and P–OH groups of nanohydroxyapatite with water molecules of the gel. A schematic was developed demonstrating changes in bonding interactions among constituent phases with respect to nanohydroxyapatite content emphasizing the importance of material interactions while fabricating multi‐phase nanocomposites for various biomedical applications. Copyright © 2017 John Wiley & Sons, Ltd.