US EPA

9960467 

Journal Article 

Long-lasting anti-bacterial activity and bacteriostatic mechanism of tea tree oil adsorbed on the amino-functionalized mesoporous silica-coated by PAA 

Gao, F; Zhou, H; Shen, Z; Zhu, G; Hao, L; Chen, H; Xu, H; Zhou, X 

2020 

Yes 

Colloids and Surfaces B: Biointerfaces
ISSN: 0927-7765
EISSN: 1873-4367 

188 

110784 

English 

31935631 

10.1016/j.colsurfb.2020.110784 

WOS:000527305100038 

Tea tree oil (TTO) is an efficient natural antibacterial agent. However, the bacteriostatic effect of TTO does not prevail for a long period because of the volatile nature of the oil. Therefore, a novel sustained-release formulation of TTO should be developed for improving the applicability of TTO. Herein, the mesoporous silica was selected for constructing a carrier for TTO. Mesoporous silica is non-toxic, easy to modify and exhibited an adjustable pore size. First, the mesoporous silica was modified by an aminated silane coupling agent (NH2-MCM-41). Then, the polyacrylic acid (PAA) was bonded by electrostatic bonds (PAA-NH2-MCM-41), which imparted the sustained-release effect in the TTO, supported in the mesoporous silica channel (TTO/PAA-NH2-MCM-41). The prepared bacteriostatic agent can achieve long-term sustained-release properties. At room temperature (26 ℃), the release rate of TTO after 11 h release reached 50 %. However, the release rate of TTO from TTO/PAA-NH2-MCM-8 reached only 42 % after 24 h. Furthermore, the sustained release behavior of TTO/PAA-NH2-MCM-41 was consistent with the Korsmeyer-Peppas kinetic model. Compared to TTO, TTO/PAA-NH2-MCM-41 exhibited a stable and sustained bacteriostatic effect even after 50 days in a natural environment. The minimum inhibitory concentration (MIC) value of the TTO/PAA-NH2-MCM-41 against Escherichia coli (E. coli) was 0.37∼0.44 mg/mL. TTO altered the cell morphology of E. coli and broke the integrity of the cell membrane, leading to cell death.