Disruption of Enterococcus Faecalis biofilms using individual and plasma polymer encapsulated D-amino acids
CLINICAL ORAL INVESTIGATIONS
Authors: Khider, Dunia; Rossi-Fedele, Giampiero; Fitzsimmons, Tracy; Vasilev, Krasimir; Zilm, Peter S.
Abstract
Objective Our aim was to assess the anti-biofilm ability of previously unverified individual D-amino acids (DAAs), to produce plasma polymer encapsulated DAAs (PPEDAAs), to measure the shell thickness and subsequent release of DAAs, and to assess the effects of PPEDAAs on Enterococcus faecalis biofilms. Materials and methods Microtitre tray assays were used to evaluate the effect of individual DAAs (D-leucine, D-methionine, D-tryptophan, and D-tyrosine) on E. faecalis biofilms of different maturity. A mixture and individual DAAs were encapsulated with a plasma polymer for 10, 20, 40, and 60 min. The shell thickness of PPEDAAs was analyzed by ultra-high-resolution scanning electron microscopy. The release of DAAs from the PPEDAAs encapsulated for 60 min was measured over 7 days using high-performance liquid chromatography. Static biofilms were used to assess the effect of PPEDAAs on E. faecalis biofilms. Results Individual DAAs reduced biofilm formation to various degrees, according to the DAA and the experimental times. The shell thicknesses of the PPEDAAs ranged between 31 and 76 nm and increased with encapsulation time. Diffusion of DAAs from the PPEDAAs occurred over 60 min for encapsulated D-leucine, D-methionine, and D-tyrosine and up to 7 days for D-tryptophan. PPEDAAs disrupted biofilms at every experimental time. Conclusions PPEDAAs of various shell thickness can be produced with the proposed methodology, DAAs are subsequently released, and the anti-biofilm activity remains unaltered.
Systemic Steroid Treatment for Imatinib-Associated Severe Skin Rash in Patients with Gastrointestinal Stromal Tumor: A Phase II Study
ONCOLOGIST
Authors: Kim, Eo Jin; Ryu, Min-Hee; Park, Sook Ryun; Beck, Mo Youl; Lee, Woo Jin; Lee, Mi Woo; Kang, Yoon-Koo
Abstract
Background To achieve optimal clinical outcomes in patients with gastrointestinal stromal tumor (GIST), it is crucial to maintain sufficient dosing of imatinib. Skin rash is a common imatinib-associated adverse event and may affect compliance. This phase II study was conducted to evaluate whether imatinib-associated severe skin rash can be managed with systemic steroids without dose reduction or interruption of imatinib. This study is registered at , number NCT03440515. Patients and Methods Between 2014 and 2016, 29 patients with imatinib-associated severe skin rash were enrolled. Skin rash of grade 2 with grade >= 2 pruritus or of grade 3 was considered severe. Oral prednisolone was administered 30 mg/day for 3 weeks, then tapered off over 12 weeks. The primary endpoint was treatment success rate (TSR). Treatment success was defined as maintaining imatinib for more than 15 weeks after completion of the steroid administration schedule without skin rash that led to additional steroid treatment or dose reduction or interruption of imatinib. Results Of the 29 patients enrolled, 22 patients with skin rash were treated successfully (TSR, 75.8%), 2 (6.9%) were evaluated as treatment failures, and 5 (17.2%) were not evaluable. The 2-year rash-free and imatinib reduction-free interval rate was 67.2% with median follow-up of 22.0 months (range, 0.4-30.3). Recurrence of severe skin rash occurred in seven patients (24.1%). Systemic steroids were well tolerated except in one patient who experienced pneumocystis pneumonia. Conclusion This study demonstrated that imatinib-associated severe skin rash can be effectively controlled by systemic steroid treatment without interruption or dose reduction of imatinib in patients with GIST. Implications for Practice Imatinib has been the standard treatment of gastrointestinal stromal tumor in both adjuvant and palliative settings. It is crucial to maintain sufficient dosing of imatinib to achieve optimal clinical outcomes. Imatinib commonly causes imatinib-associated skin rash, which may worsen drug compliance. This phase II study demonstrated that systemic steroids could help maintaining the efficacy of imatinib by preventing interruption or dose reduction of imatinib. The present study provides a new administration strategy of systemic steroids and its efficacy and safety data. Thus, this study can be a cornerstone to establish treatment guidelines for imatinib-associated skin rash.