PMID- 32261635
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200408
IS  - 2050-7518 (Electronic)
IS  - 2050-750X (Linking)
VI  - 2
IP  - 14
DP  - 2014 Apr 14
TI  - A thermally triggered in situ hydrogel from poly(acrylic 
      acid-co-N-isopropylacrylamide) for controlled release of anti-glaucoma drugs.
PG  - 1988-1997
LID - 10.1039/c3tb21360a [doi]
AB  - The purpose of this study was to develop and evaluate thermally responsive 
      copolymers, which contain temperature- and pH-sensitive segments that are either 
      alternating in or grafted onto the main chain, and to exploit their 
      temperature-sensitive properties for ophthalmic drug delivery. Accordingly, two 
      types of thermoresponsive copolymers-a linear poly(acrylic 
      acid-co-N-isopropylacrylamide) random copolymer (PAAc-co-PNIPAAm) and a 
      poly(acrylic acid-g-N-isopropylacrylamide) graft copolymer (PAAc-g-PNIPAAm)-were 
      investigated for their thermosensitive in situ gel formation and potential 
      applications for ophthalmic drug delivery. All the PAAc-g-PNIPAAm graft 
      copolymers, and the linear PAAc-co-PNIPAAm copolymer with low acrylic acid 
      contents, have an LCST of 34  degrees C; this is close to the surface temperature of the 
      eye and can therefore be utilized for ophthalmic drug delivery. In addition, the 
      PAAc-g-PNIPAAm graft copolymers showed a higher water content than the linear 
      random copolymer; this is due to the high water adsorption ability of PAAc. The 
      drug release dynamics of [(3)H]-epinephrine as a model showed that the linear 
      random copolymer has a faster drug release, while the graft copolymers showed a 
      more sustained release profile. The Ritger-Peppas model was used to account for 
      the release of the epinephrine diffusion exponent 'n' which was in between 0.5 
      and 0.6. The release of the drug is considered mainly dependent on diffusion but 
      other factors cannot be excluded. We suspected that the dynamics of drug release 
      are determined by the water adsorption ability because high water content results 
      in the formation of a larger capillary network in the polymer matrix, which 
      promotes drug diffusion into the copolymer. The results suggest that 
      PAAc-g-PNIPAAm graft copolymers are potential thermosensitive in situ gel-forming 
      materials for ophthalmic drug delivery.
FAU - Prasannan, Adhimoorthy
AU  - Prasannan A
AD  - Department of Chemical Engineering/R&D Center for Membrane Technology, Chung Yuan 
      University, Chung Li 320, Taiwan. ghhsiue@mx.nthu.edu.tw.
FAU - Tsai, Hsieh-Chih
AU  - Tsai HC
FAU - Chen, Yu-Shuan
AU  - Chen YS
FAU - Hsiue, Ging-Ho
AU  - Hsiue GH
LA  - eng
PT  - Journal Article
DEP - 20140227
PL  - England
TA  - J Mater Chem B
JT  - Journal of materials chemistry. B
JID - 101598493
SB  - IM
EDAT- 2014/04/14 00:00
MHDA- 2014/04/14 00:01
CRDT- 2020/04/09 06:00
PHST- 2020/04/09 06:00 [entrez]
PHST- 2014/04/14 00:00 [pubmed]
PHST- 2014/04/14 00:01 [medline]
AID - 10.1039/c3tb21360a [doi]
PST - ppublish
SO  - J Mater Chem B. 2014 Apr 14;2(14):1988-1997. doi: 10.1039/c3tb21360a. Epub 2014 
      Feb 27.