Materials Science and Engineering Department, Drexel University, Philadelphia, PA 19104, USA.
Carbohydr Polym. 2013 Jun 5;95(1):123-33. doi: 10.1016/j.carbpol.2013.02.034. Epub 2013 Feb 26.
Electrospun chitosan fibers have numerous potential in biomedical, food, and pharmaceutical applications. However, the mats formed are often not chemically stable in a wide range of pHs unless crosslinked. Here, we report on the use of glycerol phosphate (GP), tripolyphosphate (TPP) and tannic acid (TA) as a new set of non-covalent crosslinkers for electrospun chitosan fibers. Crosslinking with or without heat or base activation were performed either prior to (one-step or activated one-step) or after (two-step or activated two-step) electrospinning with either GP or TA. TPP crosslinking was performed in two-step and activated two-step. FESEM, FTIR and UV-vis transmittance at 600 nm were used to determine fiber surface morphology, chemical interactions and solubility in 1M AA (pH 3), water (~pH 6) and 1 M NaOH (pH 13), respectively. Crosslinking of chitosan with GP and TA yields fibers with a mean diameter range of 145-334 nm and 143-5554 nm, respectively. TPP crosslinking produced branched fibers with mean diameters of 117-462 nm range. Two-step chitosan-TA did not dissolve in 1M AA even after 72 h while all chitosan-TPP, activated two-step chitosan-TA and two-step heat activated chitosan-GP fibers survived in water after 72 h.
静电纺丝壳聚糖纤维在生物医学、食品和制药等领域具有广泛的应用前景。然而，未经交联处理，这些纤维在广泛的 pH 值范围内通常化学稳定性较差。在这里，我们报告了使用甘油磷酸（GP）、三聚磷酸（TPP）和鞣酸（TA）作为一种新的非共价交联剂用于静电纺丝壳聚糖纤维。交联可以在静电纺丝之前（一步或激活一步）或之后（两步或激活两步）进行，使用 GP 或 TA 进行交联，无需加热或碱激活。TPP 交联在两步和激活两步中进行。FESEM、FTIR 和在 600nm 处的紫外-可见透射率分别用于确定纤维表面形貌、化学相互作用以及在 1M AA（pH 3）、水（~pH 6）和 1M NaOH（pH 13）中的溶解度。壳聚糖与 GP 和 TA 的交联得到的纤维平均直径分别为 145-334nm 和 143-5554nm。TPP 交联产生的支化纤维平均直径范围为 117-462nm。两步壳聚糖-TA 即使在 72 小时后也不会溶解在 1M AA 中，而所有壳聚糖-TPP、激活两步壳聚糖-TA 和两步热激活壳聚糖-GP 纤维在 72 小时后仍能在水中存活。
