Sıcaklığa Duyarlı PNIPAM Hidrojellerde Çapraz Bağlayıcı ve Başlatıcı Sisteminin Karşılaştırılması

Year 2019, , 1237 - 1248, 31.07.2019

Pinar Cakir Hatir , Ozlem Yalcin Capan

https://doi.org/10.29130/dubited.544824

Cited By: 1

Abstract

Thermoresponsive
hydrogels are three-dimensional polymer networks which undergo conformational
changes in aqueous media depending on the external temperature. As the lower
critical temperature (LCST) is close to the body temperature,
poly(N-isopropylacrylamide) (PNIPAM) is the main thermoresponsive hydrogel used
for biomedical applications. Below LCST, PNIPAM hydrogels swell in aqueous
media, above LCST they become insoluble and shrink. This behavior makes it
possible to design drug release systems controlled by external temperature.
Swelling/shrinking response of PNIPAM hydrogel depends on several factors such
as crosslinker type, crosslinking density, hydrophobic/hydrophilic balance and
initiator type. In this study, the effects of the initiation system and the
crosslinker type on different thermoresponsive hydrogels were compared. For
this purpose, thermoresponsive hydrogels were synthesized by using ethylene
glycol dimethylacrylate (EGDMA) and N,N′-ethylene bisacrylamide (EBAM) as
crosslinkers via photo and thermal initiation systems. The hydrogels were
characterized by FTIR spectroscopy and scanning electron microscope (SEM).
Effects of the initiation system and the crosslinker type on the release,
swelling behavior, morphology and the biocompatibility behavior of the
hydrogels were investigated. The hydrogels synthesized with EBAM demonstrated more
promising results compared to the one synthesized EGDMA. It was concluded that
poly(EBAM-co-NIPAM)-P has the highest swelling ratio and poly(EBAM-co-NIPAM)-T
is the most biocompatible hydrogel. In terms of release characteristics, there was
not a significant difference between the hydrogels, even though their swelling
characteristics differ.

Keywords

Thermoresponsive hydrogels, photopolymerization, thermal polymerization, N-isopropylacrylamide

Comparison of Crosslinker Types and Initiation Systems of Thermoresponsive PNIPAM Hydrogels

Abstract

Thermoresponsive
hydrogels are three-dimensional polymer networks which undergo conformational
changes in aqueous media depending on the external temperature. As the lower
critical temperature (LCST) is close to the body temperature,
poly(N-isopropylacrylamide) (PNIPAM) is the main thermoresponsive hydrogel used
for biomedical applications. Below LCST, PNIPAM hydrogels swell in aqueous
media, above LCST they become insoluble and shrink. This behavior makes it
possible to design drug release systems controlled by external temperature.
Swelling/shrinking response of PNIPAM hydrogel depends on several factors such
as crosslinker type, crosslinking density, hydrophobic/hydrophilic balance and
initiator type. In this study, the effects of the initiation system and the
crosslinker type on different thermoresponsive hydrogels were compared. For
this purpose, thermoresponsive hydrogels were synthesized by using ethylene
glycol dimethylacrylate (EGDMA) and N,N′-ethylene bisacrylamide (EBAM) as
crosslinkers via photo and thermal initiation systems. The hydrogels were
characterized by scanning electron microscope (SEM) and FTIR spectroscopy. Effects
of the initiation system and the crosslinker type on the release, swelling
behavior, morphology and the biocompatibility behavior of the hydrogels were
investigated. The hydrogels synthesized with EBAM demonstrated more promising
results compared to the one synthesized EGDMA. It was concluded that poly(EBAM-co-NIPAM)-P
has the highest swelling ratio and poly(EBAM-co-NIPAM)-T is the most
biocompatible hydrogel. In terms of release characteristics, there was not a
significant difference between the hydrogels, even though their swelling
characteristics differ.

Keywords

Sıcaklığa duyarlı hidrojeller, fotopolimerizasyon, termal polimerizasyon, N-izopropilakrilamid

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