Hiebner, Dishon W.
Hiebner, Dishon W.
Hiebner, Dishon W.
Now showing 1 - 3 of 3
- PublicationInteraction between Engineered Pluronic Silica Nanoparticles and Bacterial Biofilms: Elucidating the Role of Nanoparticle Surface Chemistry and EPS Matrix(American Chemical Society, 2022-08-03)
; ; ; ; ; ;Nanoparticles (NPs) are considered a promising tool in the context of biofilm control. Many studies have shown that different types of NPs can interfere with the bacterial metabolism and cellular membranes, thus making them potential antibacterial agents; however, fundamental understanding is still lacking on the exact mechanisms involved in these actions. The development of NP-based approaches for effective biofilm control also requires a thorough understanding of how the chosen nanoparticles will interact with the biofilm itself, and in particular with the biofilm self-produced extracellular polymeric matrix (EPS). This work aims to provide advances in the understanding of the interaction between engineered fluorescent pluronic silica (PluS) nanoparticles and bacterial biofilms, with a main focus on the role of the EPS matrix in the accumulation and diffusion of the particles in the biofilm. It is demonstrated that particle surface chemistry has a key role in the different lateral distribution and specific affinity to the biofilm matrix components. The results presented in this study contribute to our understanding of biofilm-NP interactions and promote the principle of the rational design of smart nanoparticles as an important tool for antibiofilm technology. 5Scopus© Citations 1
- PublicationEnhancing curcumin's solubility and antibiofilm activity via silica surface modification(Royal Society of Chemistry, 2020-03-20)
; ; ; ; ;Bacterial biofilms are microbial communities in which bacterial cells in sessile state are mechanically andchemically protected against foreign agents, thus enhancing antibiotic resistance. The delivery of activecompounds to the inside of biofilms is often hindered due to the existence of the biofilm extracellularpolymeric substances (EPS) and to the poor solubility of drugs and antibiotics. A possible strategy toovercome the EPS barrier is the incorporation of antimicrobial agents into a nanocarrier, able topenetrate the matrix and deliver the active substance to the cells. Here, we report the synthesis ofantimicrobial curcumin-conjugated silica nanoparticles (curc-NPs) as a possibility for dealing with theseissues. Curcumin is a known antimicrobial agent and to overcome its low solubility in water it wasgrafted onto the surface of silica nanoparticles, the latter functioning as nanocarrier for curcumin intothe biofilm. Curc-NPs were able to impede the formation of modelP. putidabiofilms up to 50% anddisrupt mature biofilms up to 54% at 2.5 mg mL 1. Cell viability of sessile cells in both cases was alsoconsiderably affected, which is not observed for curcumin delivered as a free compound at the sameconcentration. Furthermore, proteomics of extracted EPS matrix of biofilms grown in the presence offree curcumin and curc-NPs revealed differences in the expression of key proteins related to celldetoxification and energy production. Therefore, curc-NPs are presented here as an alternative forcurcumin delivery that can be exploited not only to other bacterial strains but also to further biologicalapplications. 181Scopus© Citations 21
- PublicationSurface functionalization-dependent localization and affinity of SiO2 nanoparticles within the biofilm EPS matrix(Elsevier, 2020-12)
; ; ; ;The contribution of the biofilm extracellular polymeric substance (EPS) matrix to reduced antimicrobial sus-ceptibility in biofilms is widely recognised. As such, the direct targeting of the EPS matrix is a promising biofilmcontrol strategy that allows for the disruption of the matrix, thereby allowing a subsequent increase in suscep-tibility to antimicrobial agents. To this end, surface-functionalized nanoparticles (NPs) have received considerableattention. However, the fundamental understanding of the interactions occurring between engineered NPs andthe biofilm EPS matrix has not yet been fully elucidated. An insight into the underlying mechanisms involvedwhen a NP interacts with the EPS matrix will aid in the design of more efficient NPs for biofilm control. Here wedemonstrate the use of highly specificfluorescent probes in confocal laser scanning microscopy (CLSM) toillustrate the distribution of EPS macromolecules within the biofilm. Thereafter, a three-dimensional (3D)colocalization analysis was used to assess the affinity of differently functionalized silica NPs (SiNPs) and EPSmacromolecules fromPseudomonasfluorescensbiofilms. Results show that both the charge and surface functionalgroups of SiNPs dramatically affected the extent to which SiNPs interacted and localized with EPS macromole-cules, including proteins, polysaccharides and DNA. Hypotheses are also presented about the possible physico-chemical interactions which may be dominant in EPS matrix-NP interactions. This research not only develops aninnovative CLSM-based methodology for elucidating biofilm-nanoparticle interactions but also provides a plat-form on which to build more efficient NP systems for biofilm control. 118Scopus© Citations 15