Ionically crosslinked chitosan/tripolyphosphate (Chit/TPP) particles have been widely tested in biomedical applications, particularly as potential carriers for controlled drug delivery. Since Chit/TPP particles are typically prepared under acidic conditions, their application in physiological environment and correct evaluation of biological data ultimately require knowledge on their physico-chemical properties and overall behaviour at physiological pH, as they may differ substantially from those exhibited after preparation. In this study, Chit/TPP complexes prepared at pH 4.43 were exposed to a physiological and slightly alkaline pH of 7.42 and 8.90, respectively, and analysed by inductively coupled plasma mass spectrometry and Fourier transform infrared spectroscopy with attenuated total reflectance for TPP content. In parallel, osmolarity measurements as well as theoretical calculations were used to interpret the composition and behaviour of Chit/TPP complexes upon pH elevation. Exposure of Chit/TPP complexes to a pH in the physiological range resulted in their practically complete dissociation into free chitosan chains. This leads to a significant consequence that Chit/TPP particles prepared at acidic pH do not exist under physiological conditions.

离子交联的壳聚糖/三聚磷酸盐（Chit / TPP）颗粒已在生物医学应用中进行了广泛测试，尤其是作为可控药物递送的潜在载体。由于Chit / TPP颗粒通常是在酸性条件下制备的，因此它们在生理环境中的应用以及对生物学数据的正确评估最终需要了解其理化性质和在生理pH值下的总体行为，因为它们可能与制备后所表现出的性质大不相同。在这项研究中，将在pH 4.43下制备的Chit / TPP配合物分别暴露在7.42和8.90的生理和弱碱性pH下，并通过电感耦合等离子体质谱和傅里叶变换红外光谱法对TPP含量进行了衰减，从而对其进行了分析。在平行下，渗透压测量和理论计算用于解释pH升高时Chit / TPP复合物的组成和行为。将Chit / TPP复合物暴露于生理范围内的pH值会导致它们实际上完全解离为游离的壳聚糖链。这导致显着的结果是，在酸性条件下制备的Chit / TPP颗粒在生理条件下不存在。