TY - JOUR
T1 - Rationally designed chitosan-interpenetrated cryobeads functionalized with polyacrylamide chains
T2 - Comparative analysis by Hertzian model and rubber elasticity
AU - Kalkan, Birgul
AU - Bozbay, Rabia
AU - Ciftbudak, Sena
AU - Orakdogen, Nermin
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/12/31
Y1 - 2023/12/31
N2 - Optimization of the synthesis of polymer microspheres and millimeter-sized gel beads has gained importance due to efficiency and design advantages in applications. A systematic study is presented to allow for a molecular-based understanding of elasticity of crosslinked-chitosan (CS) beads. Unique results were obtained examining the effect of polymerization temperature and gel-preparation form on physico-mechanical properties of CS-incorporated poly (N-isopropylacrylamide‑sodium acrylate)/polyacrylamide, PNIPA/PAAm-CS, beads. ATR-FTIR, and thermogravimetric analysis results confirmed the successful preparation and enhanced thermal stability of CS-based gel beads in the form of semi-IPN. The structural changes of semi-IPN gels were studied based on powder X-ray diffraction analysis. After being incorporated with CS, the cryopolymerization was carried out under cryo-conditions, and PNIPA/PAAm structure became much more resistant to mechanical load. Addition of CS to semi-IPN structure caused a 2-fold increase in compressive elastic modulus, while the gel preparation under cryoconditions also improved the mechanical properties considerably by lowering the polymerization temperature. The scaling parameter calculations estimated by Hertz model for PNIPA/PAAm-CS semi-IPN cryobeads are related to displacement of compression force with an exponent of 1.63 ± 0.19. As cryobead diameter increased, swelling degree tendency increased, while a decrease in modulus was observed with increasing swelling. The presence of CS in semi-IPNs improved pH-response in an acidic environment, but stiffness of CS reduced the shrinkage ability of cryobeads upon increasing swelling temperature. Based on the interaction between semi-IPN structure and salt solutions, an improvement in elastic modulus was observed in various ammonium salts and sodium tripolyphosphate solution. On-off switching of cryobeads was a reversible process that was consistent with changes in ammonium salt concentration. Qualitative comparisons with experimental results showed that the prepared cryobeads can be designed as drug release carriers by ionic strength-switching modulation.
AB - Optimization of the synthesis of polymer microspheres and millimeter-sized gel beads has gained importance due to efficiency and design advantages in applications. A systematic study is presented to allow for a molecular-based understanding of elasticity of crosslinked-chitosan (CS) beads. Unique results were obtained examining the effect of polymerization temperature and gel-preparation form on physico-mechanical properties of CS-incorporated poly (N-isopropylacrylamide‑sodium acrylate)/polyacrylamide, PNIPA/PAAm-CS, beads. ATR-FTIR, and thermogravimetric analysis results confirmed the successful preparation and enhanced thermal stability of CS-based gel beads in the form of semi-IPN. The structural changes of semi-IPN gels were studied based on powder X-ray diffraction analysis. After being incorporated with CS, the cryopolymerization was carried out under cryo-conditions, and PNIPA/PAAm structure became much more resistant to mechanical load. Addition of CS to semi-IPN structure caused a 2-fold increase in compressive elastic modulus, while the gel preparation under cryoconditions also improved the mechanical properties considerably by lowering the polymerization temperature. The scaling parameter calculations estimated by Hertz model for PNIPA/PAAm-CS semi-IPN cryobeads are related to displacement of compression force with an exponent of 1.63 ± 0.19. As cryobead diameter increased, swelling degree tendency increased, while a decrease in modulus was observed with increasing swelling. The presence of CS in semi-IPNs improved pH-response in an acidic environment, but stiffness of CS reduced the shrinkage ability of cryobeads upon increasing swelling temperature. Based on the interaction between semi-IPN structure and salt solutions, an improvement in elastic modulus was observed in various ammonium salts and sodium tripolyphosphate solution. On-off switching of cryobeads was a reversible process that was consistent with changes in ammonium salt concentration. Qualitative comparisons with experimental results showed that the prepared cryobeads can be designed as drug release carriers by ionic strength-switching modulation.
KW - Chitosan
KW - Cryobead
KW - Elasticity
KW - pH-response
KW - Swelling
UR - http://www.scopus.com/inward/record.url?scp=85175054392&partnerID=8YFLogxK
U2 - 10.1016/j.ijbiomac.2023.127483
DO - 10.1016/j.ijbiomac.2023.127483
M3 - Article
C2 - 37863149
AN - SCOPUS:85175054392
SN - 0141-8130
VL - 253
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
M1 - 127483
ER -