Polydimethylsiloxane (PDMS) is widely used as a cell culture platform to produce micro- and nano-technology based microdevices. However, the native PDMS surface is not suitable for cell adhesion and is always subject to bacterial pollution and cancer cell invasion. Coating the PDMS surface with antibacterial or anticancer materials often causes considerable harm to the non-cancer mammalian cells on it. We have developed a method to fabricate a biocompatible PDMS surface which not only promotes non-cancer mammalian cell growth but also has antibacterial and anticancer activities, by coating the PDMS surface with a Chinese herb extract, paeonol. Coating changes the wettability and the elemental composition of the PDMS surface. Molecular dynamic simulation indicates that the absorption of paeonol onto the PDMS surface is an energy favourable process. The paeonol-coated PDMS surface exhibits good antibacterial activity against both Gram-positive and Gram-negative bacteria. Moreover considerable antibacterial activity is maintained after the coated surface is rinsed or incubated in water. The coated PDMS surface inhibits bacterial growth on the contact surface and promotes non-cancer mammalian cell growth with low cell toxicity; meanwhile the growth of cancer cells is significantly inhibited. Our study will potentially guide PDMS surface modification approaches to produce biomedical devices.
Ji Li,Yanping Li,Shuang Pan,Lin Zhang,Lina He,Yumei Niu
Paeonol is a natural phenolic compound in Moutan Cortex with multiple biological functions, such as anti-inflammatory and anti-oxidant activity. Recent evidence has proven that persistent inflammation, oxidative stress , along with nuclear factor E2-related factor 2 (Nrf2) signaling dysfunction in periodontium are the possible causes of alveolar bone resorption , and ultimately lead to periodontitis. The present study was designed to explore the protective effects of paeonol on ligation-induced periodontitis in rats, and investigate the possible mechanism. We found that treatment with paeonol (40, 80 mg/kg, intraperitoneal injection) for 7 days remarkably decreased the expression of receptor activator of nuclear factor kappa-B ligand increased the expression of osteoprotegrin and inhibited the formation of osteoclasts . This function of paeonol might be correlated with its ability to reduce inflammatory factors (IL-1β, IL-6 and TNF-α) and alleviate oxidative stress (SOD, MDA, GSH and ROS) in gingival tissues. Besides, paeonol increased Nrf2 activity. Silence of Nrf2 using specific siRNA diminished the inhibitory effect of paeonol on NF-κB p65 activation and downstream expression, suggesting that Nrf2 was essential for protective effect of paeonol. These results showed that paeonol protected against periodontitis-aggravated osteoclastogenesis and alveolar bone lesion via regulating Nrf2/NF-κB/NFATc1 signaling pathway .