Phothong Natthaphat, Pattarakankul Thitiporn, Morikane Shiho, Palaga Tanapat, Aht-Ong Duangdao, Honda Kohsuke, Napathorn Suchada Chanprateep
Program in Biotechnology, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
Department of Microbiology, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand.
Int J Biol Macromol. 2024 Jun;271(Pt 2):132680. doi: 10.1016/j.ijbiomac.2024.132680. Epub 2024 May 26.
Microbeads of biodegradable polyhydroxybutyrate (PHB) offer environmental benefits and economic competitiveness. The aim of this study was to encapsulate a water-soluble bioactive compound, niacinamide (NIA), in a pH-responsive natural matrix composed of PHB and cellulose acetate phthalate (CAP) by double emulsification (W1/O/W2) to improve the encapsulation efficiency (%EE) and loading capacity (%LC). PHB was produced in-house by Escherichia coli JM109 pUC19-23119phaCAB without the inducing agent isopropyl β-D-1-thiogalactopyranoside (IPTG). The influences of PHB and polyvinyl alcohol (PVA) concentrations, stirring rate, PHB/CAP ratio and initial NIA concentration on the properties of NIA-loaded pH-responsive microbeads were studied. The NIA-loaded pH-responsive PHB/CAP microbeads exhibited a spherical core-shell structure. The average size of the NIA-loaded pH-responsive microbeads was 1243.3 ± 11.5 μm. The EE and LC were 33.3 ± 0.5 % and 28.5 ± 0.4 %, respectively. The release profiles of NIA showed pH-responsive properties, as 94.2 ± 3.5 % of NIA was released at pH 5.5, whereas 99.3 ± 2.4 % of NIA was released at pH 7.0. The NIA-loaded pH-responsive PHB/CAP microbeads were stable for >90 days at 4 °C under darkness, with NIA remaining at 73.65 ± 1.86 %. A cytotoxicity assay in PSVK1 cells confirmed that the NIA-loaded pH-responsive PHB/CAP microbeads were nontoxic at concentrations lower than 31.3 μg/mL, in accordance with ISO 10993-5.
可生物降解的聚羟基丁酸酯（PHB）微珠具有环境效益和经济竞争力。本研究的目的是通过双乳化法（W1/O/W2）将水溶性生物活性化合物烟酰胺（NIA）包裹在由PHB和邻苯二甲酸醋酸纤维素（CAP）组成的pH响应性天然基质中，以提高包封效率（%EE）和载药量（%LC）。PHB由大肠杆菌JM109 pUC19 - 23119phaCAB在无诱导剂异丙基β - D - 1 - 硫代半乳糖苷（IPTG）的情况下在内部生产。研究了PHB和聚乙烯醇（PVA）浓度、搅拌速率、PHB/CAP比例以及初始NIA浓度对负载NIA的pH响应性微珠性能的影响。负载NIA的pH响应性PHB/CAP微珠呈现出球形核壳结构。负载NIA的pH响应性微珠的平均尺寸为1243.3 ± 11.5μm。包封率和载药量分别为33.3 ± 0.5%和28.5 ± 0.4%。NIA的释放曲线显示出pH响应特性，在pH 5.5时94.2 ± 3.5%的NIA被释放，而在pH 7.0时99.3 ± 2.4%的NIA被释放。负载NIA的pH响应性PHB/CAP微珠在4℃黑暗条件下稳定>90天，NIA含量保持在73.65 ± 1.86%。在PSVK1细胞中的细胞毒性试验证实，根据ISO 10993 - 5标准，负载NIA的pH响应性PHB/CAP微珠在浓度低于31.3μg/mL时无毒。
