Lisuzzo Lorenzo, Cavallaro Giuseppe, Milioto Stefana, Lazzara Giuseppe
Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze, pad. 17, 90128 Palermo, Italy.
Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Via G. Giusti, 9, I-50121 Firenze, Italy.
Polymers (Basel). 2020 Aug 7;12(8):1766. doi: 10.3390/polym12081766.
In this work, we have developed a novel strategy to prepare hybrid nanostructures with controlled release properties towards khellin by exploiting the electrostatic interactions between chitosan and halloysite nanotubes (HNT). Firstly, khellin was loaded into the HNT lumen by the vacuum-assisted procedure. The drug confinement within the halloysite cavity has been proved by water contact angle experiments on the HNT/khellin tablets. Therefore, the loaded nanotubes were coated with chitosan as a consequence of the attractions between the cationic biopolymer and the halloysite outer surface, which is negatively charged in a wide pH range. The effect of the ionic strength of the aqueous medium on the coating efficiency of the clay nanotubes was investigated. The surface charge properties of HNT/khellin and chitosan/HNT/khellin nanomaterials were determined by ζ potential experiments, while their morphology was explored through Scanning Electron Microscopy (SEM). Water contact angle experiments were conducted to explore the influence of the chitosan coating on the hydrophilic/hydrophobic character of halloysite external surface. Thermogravimetry (TG) experiments were conducted to study the thermal behavior of the composite nanomaterials. The amounts of loaded khellin and coated chitosan in the hybrid nanostructures were estimated by a quantitative analysis of the TG curves. The release kinetics of khellin were studied in aqueous solvents at different pH conditions (acidic, neutral and basic) and the obtained data were analyzed by the Korsmeyer-Peppas model. The release properties were interpreted on the basis of the TG and ζ potential results. In conclusion, this study demonstrates that halloysite nanotubes wrapped by chitosan layers can be effective as drug delivery systems.
在本研究中，我们开发了一种新策略，通过利用壳聚糖与埃洛石纳米管（HNT）之间的静电相互作用来制备对凯林具有控释性能的杂化纳米结构。首先，通过真空辅助程序将凯林载入HNT管腔。通过对HNT/凯林片剂进行水接触角实验，证明了药物被限制在埃洛石腔内。因此，由于阳离子生物聚合物与在较宽pH范围内带负电的埃洛石外表面之间的吸引力，负载的纳米管被壳聚糖包覆。研究了水介质离子强度对粘土纳米管包覆效率的影响。通过ζ电位实验测定了HNT/凯林和壳聚糖/HNT/凯林纳米材料的表面电荷性质，同时通过扫描电子显微镜（SEM）探究了它们的形态。进行水接触角实验以探究壳聚糖包覆对埃洛石外表面亲水/疏水特性的影响。进行热重分析（TG）实验以研究复合纳米材料的热行为。通过对TG曲线的定量分析估算了杂化纳米结构中负载的凯林和包覆的壳聚糖的量。在不同pH条件（酸性、中性和碱性）的水性溶剂中研究了凯林的释放动力学，并通过Korsmeyer-Peppas模型对所得数据进行了分析。基于TG和ζ电位结果对释放特性进行了解释。总之，本研究表明，被壳聚糖层包裹的埃洛石纳米管可作为有效的药物递送系统。
