pH-responsive physical gels from poly(meth)acrylic acid-containing crosslinked particles: the relationship between structure and mechanical properties
pH-responsive physical gels from poly(meth)acrylic acid-containing crosslinked particles: the relationship between structure and mechanical properties
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DOI：
10.1039/c3tb20758g
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发表时间：
2013-01-01
影响因子：
7
通讯作者：
Saunders, Brian R.
中科院分区：
文献类型：
--
作者：
Halacheva, Silvia S.;Freemont, Tony J.;Saunders, Brian R.
具有高内部孔隙率并具有高弹性和延展性的凝胶具有提供即时负荷支撑的潜力，并且如果与细胞组合，则能够使受损软组织的后续组织再生。在此，我们报告的结果，从最近的研究新的聚（甲基丙烯酸甲酯-共-甲基丙烯酸），（PMMA-MAA）和聚（丙烯酸乙酯-共-甲基丙烯酸），（PEA-MAA）生物降解，pH值敏感的颗粒凝胶，具有高孔隙率，弹性和延展性。这些凝胶在生理pH范围内形成，并且可能是可注射的。使用溶剂蒸发制备颗粒。它们通过用胱胺（CYS）或3，3 '-二硫代二丙酸二酰肼（DTP）经由双酰胺形成交联颗粒的MAA基团而官能化，所述双酰胺或DTP同时由于交联剂内存在二硫键而引入可逆性。通过动态光散射观察到的交联颗粒的尺寸增加pH值时明显溶胀。在生理pH值范围内，浓缩的分散体形成弹性和韧性的物理凝胶。本研究的一个关键发现是，对于类似组成的交联颗粒，从最轻度交联的颗粒中观察到形成了弹性和延展性相当大的凝胶。此外，与PMMA-MAA/CYS和PEA-MAA/CYS凝胶相比，由DTP交联的颗粒形成的凝胶具有更高的弹性、更厚的孔壁和改善的互连性。对于PMMA-MAA/ DTP凝胶，对于仅含有5wt%颗粒的凝胶，观察到高达100 kPa的弹性模量值和大于100%的屈服应变。这些新的凝胶形成分散体的机械性能的改善意味着它们现在具有作为再生医学的可注射凝胶的未来应用的良好潜力。
Gels that feature high internal porosity and have both high elasticity and ductility have potential to provide immediate load support and enable subsequent tissue regeneration of damaged soft tissue if combined with cells. Herein, we report results from a recent investigation of novel poly(methyl methacrylate-co-methacrylic acid), (PMMA-MAA) and poly(ethyl acrylate-co-methacrylic acid), (PEA-MAA) biodegradable, pH-sensitive particle gels which are with high porosity, elasticity and ductility. These gels formed at physiological pH range and are potentially injectable. The particles were prepared using solvent evaporation. They were functionalized by crosslinking the MAA groups of the particles via bis-amide formation with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP) which simultaneously incorporated reversibility due to the presence of disulphide bonds within the crosslinker. The crosslinked particles were observed by dynamic light scattering to swell appreciably in size upon increasing the pH. Concentrated dispersions formed elastic and ductile physical gels within the physiological pH range. A key finding of this study was that for crosslinked particles of similar composition the formation of considerably more elastic and ductile gels was observed from the most lightly crosslinked particles. Furthermore, compared to the PMMA-MAA/CYS and PEA-MAA/CYS gels, those formed from DTP-crosslinked particles had higher elasticity, thicker pore walls and improved interconnectivity. For the PMMA-MAA/ DTP gels an elastic modulus value as high as 100 kPa and a yield strain greater than 100% were observed for a gel containing only 5 wt% of particles. The improved mechanical properties of these new gel-forming dispersions imply that they now have good potential for future application as injectable gels for regenerative medicine.