Morrison Tessali X, Gramlich William M
Department of Chemistry, University of Maine, Orono, ME 04469, USA.
Department of Chemistry, University of Maine, Orono, ME 04469, USA; Advanced Structures and Composites Center, University of Maine, Orono, ME 04469, USA; Institute of Medicine, University of Maine, Orono, ME 04469, USA.
Carbohydr Polym. 2023 Nov 1;319:121173. doi: 10.1016/j.carbpol.2023.121173. Epub 2023 Jul 1.
Carboxymethyl cellulose modified with norbornene groups (NorCMC) and cellulose nanofibrils (CNFs) produced through mechanical refining without chemical pretreatment formed interpenetrating network hydrogels through a UV-light initiated thiol-ene reaction. The molar ratio of thiols in crosslinkers to norbornene groups off the NorCMC (T:N), total polymer weight percent in the hydrogel, and weight percent of CNFs of the total polymer content of the hydrogels were varied to control hydrogel properties. This method enabled orders of magnitude changes to behavior. Swelling in aqueous environments could be significant (>150 %) without CNFs to minimal (<15 %) with the use of 50 % CNFs. NorCMC and CNF networks interacted synergistically to create hydrogels with compression modulus values spanning 1 to 150 kPa - the values of most biological tissues. T:N and total polymer weight percent could be varied to create hydrogels with different CNF content, but the same compression modulus, targeting 10 and 100 kPa hydrogels and providing a system that can independently vary fibrillar content and bulk modulus. Analysis of the effective crosslinks, thiol-ene network mesh size, and burst release of the polymer indicated synergistic interactions of the NorCMC thiol-ene and CNFs networks. These interactions enhanced modulus and degradation control of the network under physiological conditions.
通过机械精制而非化学预处理制备的含降冰片烯基团的羧甲基纤维素（NorCMC）和纤维素纳米原纤维（CNF），通过紫外光引发的硫醇-烯反应形成互穿网络水凝胶。改变交联剂中硫醇与NorCMC上降冰片烯基团的摩尔比（T:N）、水凝胶中聚合物的总重量百分比以及水凝胶中CNF占聚合物总含量的重量百分比，以控制水凝胶的性能。该方法能够使性能发生几个数量级的变化。在水性环境中，不含CNF时溶胀可能很显著（>150%），而使用50%的CNF时溶胀最小（<15%）。NorCMC和CNF网络协同相互作用，形成压缩模量值在1至150 kPa之间的水凝胶，这与大多数生物组织的值相当。可以改变T:N和聚合物总重量百分比，以制备具有不同CNF含量但相同压缩模量的水凝胶，目标是制备压缩模量为10 kPa和100 kPa的水凝胶，并提供一个能够独立改变纤维状含量和体积模量的体系。对聚合物的有效交联、硫醇-烯网络网孔尺寸和突释的分析表明，NorCMC硫醇-烯网络与CNF网络之间存在协同相互作用。这些相互作用增强了网络在生理条件下的模量和降解控制。
