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Treating the brain is challenging due to the restrictive blood–brain barrier, and modulus-mismatched implants often cause problems. Herein, we have fabricated copolymer hydrogels from thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAAm), -r-hydrophilic polymer, poly(acrylic acid) (PAA), which are injectable and transform into soft implants above their lower critical solution temperature (LCST). PAA concentration can be leveraged to tune the LCST and viscosity of the PNIPAAm–r–PAA hydrogel in solution. Furthermore, the Young’s moduli of these materials, ranging from 1-4 kPa, are close to rat and human brain tissue, potentially leading to less inflammation and rejection due to significant modulus mismatch.
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Retention of poly( N ‐isopropylacrylamide) thin films on polycarbonate via polymer interdiffusion
Abstract This study explored the possibility of polymer interdiffusion for retaining thermoresponsive poly(N‐isopropylacrylamide) (pNIPAAm) on polycarbonate (PC). It was hypothesized that interdiffusion could be facilitated either by increasing the annealing temperature or by treating PC using air plasma (AP) and ultra‐violet ozone (UVO). The results showed that increasing annealing temperature only moderately improved pNIPAAm retention. Treating PC with AP led to an increase in surface‐active groups and a greatly enhanced retention of pNIPAAm. UVO treatment, however, severely damaged the PC layer with no noticeable enhancement on pNIPAAm retention. The retained pNIPAAm films on PC exhibited thermoresponsive behavior as evidenced by water contact angle and desired cell attachment/detachment behaviors. These results illustrate the simplicity of using polymer interdiffusion to successfully retain pNIPAAm films on a polymer, and the resulting substrates would be less expensive and more versatile than those retained on brittle supports (e.g., glass) for applications that require resilient thermoresponsive substrates.
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- Award ID(s):
- 1836429
- PAR ID:
- 10457046
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 58
- Issue:
- 19
- ISSN:
- 2642-4150
- Page Range / eLocation ID:
- p. 2728-2740
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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