Zalloum Neife Lilian, Albino de Souza Geovany, Martins Tatiana Duque
Chemistry Institute, State University of Campinas, P.O. Box 6154, 13083-971 Campinas, São Paulo, Brazil.
Chemistry Institute, Federal University of Goiás, 74690-900 Goiânia, Goiás, Brazil.
ACS Omega. 2019 May 3;4(5):8122-8135. doi: 10.1021/acsomega.9b00824. eCollection 2019 May 31.
Herein, we describe the production of poly(hydroxybutyrate--hydroxyvalerate) [P(HB-HV)]-based microspheres containing coumarin-6 (C6) or pyrene (Py) fluorophores as additives and models for hydrophobic and hydrophilic drug encapsulation. Their photophysical and morphological properties, as well as encapsulation efficiencies, are studied as this work aims to describe the influence of additive hydrophobicity/hydrophilicity on microparticle formation. These properties were studied by scanning electron microscopy, fluorescence confocal laser scanning microscopy (FCLSM), and steady-state fluorescence spectroscopy. The results show that the surfactant concentration, polymer molar mass, emulsification stirring rate, and the presence of the fluorophore and its nature are determinants of the P(HB-HV) microsphere properties. Also, encapsulation efficiency is shown to be governed by synergic effects of these parameters on the formation of microspheres. Moreover, size distribution is proved to be strongly influenced by the surfactant poly(vinyl alcohol) content. FCLSM showed that the fluorophores were efficiently encapsulated in P(HB-HV) microspheres at distinct distributions within the copolymer matrix. Surprisingly, nanospheres were observed in the microsphere surface, suggesting that microspheres are formed from nanosphere coalescence.
在此，我们描述了以聚（3-羟基丁酸酯-3-羟基戊酸酯）[P(HB-HV)]为基础的微球的制备，这些微球含有香豆素-6（C6）或芘（Py）荧光团作为添加剂，用于疏水性和亲水性药物包封的模型。由于这项工作旨在描述添加剂的疏水性/亲水性对微粒形成的影响，因此对它们的光物理和形态学性质以及包封效率进行了研究。通过扫描电子显微镜、荧光共聚焦激光扫描显微镜（FCLSM）和稳态荧光光谱对这些性质进行了研究。结果表明，表面活性剂浓度、聚合物摩尔质量、乳化搅拌速率以及荧光团的存在及其性质是P(HB-HV)微球性质的决定因素。此外，包封效率显示受这些参数对微球形成的协同作用支配。而且，尺寸分布被证明受到表面活性剂聚乙烯醇含量的强烈影响。FCLSM表明，荧光团以不同的分布有效包封在P(HB-HV)微球的共聚物基质中。令人惊讶的是，在微球表面观察到了纳米球，这表明微球是由纳米球聚结形成的。
