Growth limiting conditions and denitrification govern extent and frequency of volume detachment of biofilms

This study aims at evaluating the mechanisms of biofilm detachment with regard of the physical properties of the biofilm. Biofilms were developed in Couette–Taylor reactor under controlled hydrodynamic conditions and under different environmental growth conditions. Five different conditions were tested and lead to the formation of two aerobic heterotrophic biofilms (aeHB1 and aeHB2), a mixed autotrophic and heterotrophic biofilm (MAHB) and two anoxic heterotrophic biofilms (anHB1 and anHB2). Biofilm detachment was evaluated by monitoring the size of the detached particles (using light-scattering) as well as the biofilm physical properties (using CCD camera and image analysis). Results indicate that volume erosion of large biofilm particles with size ranging from 50 to 500 lm dominated the biomass loss for all biofilms. Surface erosion of small particles with size lower than 20 lm dominates biofilm detachment in number. The extent of the volume detachment events was governed by the size of the biofilm surface heterogeneities (i.e., the absolute biofilm roughness) but never impacted more than 80% of the mean biofilm thickness due to the highly cohesive basal layer. Anoxic biofilms were smoother and thinner than aerobic biofilms and thus associated with the detachment of smaller particles. Our results contradict the simplifying assumption of surface detachment that is considered in many biofilm models and suggest that discrete volume events should be considered

Predictive computer models for bioflim detachment properties in Pseudomonas aeruginosa

Microbial biofilm communities are protected against environmental extremes or clearance by antimicrobial agents or the host immune response. They also serve as a site from which microbial populations search for new niches by dispersion via single planktonic cells or by detachment by protected biofilm aggregates that, until recently, were thought to become single cells ready for attachment. Mathematically modeling these events has provided investigators with testable hypotheses for further study. Such was the case in the recent article by Kragh et al. (K. N. Kragh, J. B. Hutchison, G. Melaugh, C. Rodesney, A. E. Roberts, Y. Irie, P. Ø. Jensen, S. P. Diggle, R. J. Allen, V. Gordon, and T. Bjarnsholt, mBio 7:e00237-16, 2016, http://dx.doi.org/10.1128/mBio.00237-16), in which investigators were able to identify the differential competitive advantage of biofilm aggregates to directly attach to surfaces compared to the single-celled planktonic populations. Therefore, as we delve deeper into the properties of the biofilm mode of growth, not only do we need to understand the complexity of biofilms, but we must also account for the properties of the dispersed and detached populations and their effect on reseeding

Causes and biophysical consequences of cellulose production by Pseudomonas fluorescens SBW25 at the air-liquid interface

Cellulose over-producing wrinkly spreader mutants of Pseudomonas fluorescens SBW25 have been the focus of much investigation, but conditions promoting the production of cellulose in ancestral SBW25, its effects and consequences have escaped in-depth investigation through lack of in vitro phenotype. Here, using a custom built device, we reveal that in static broth microcosms ancestral SBW25 encounters environmental signals at the air-liquid interface that activate, via three diguanylate cyclase-encoding pathways (Wsp, Aws and Mws), production of cellulose. Secretion of the polymer at the meniscus leads to modification of the environment and growth of numerous micro-colonies that extend from the surface. Accumulation of cellulose and associated microbial growth leads to Rayleigh-Taylor instability resulting in bioconvection and rapid transport of water-soluble products over tens of millimetres. Drawing upon data we build a mathematical model that recapitulates experimental results and captures the interactions between biological, chemical and physical processes.IMPORTANCE This work reveals a hitherto unrecognized behaviour that manifests at the air-liquid interface, which depends on production of cellulose, and hints to undiscovered dimensions to bacterial life at surfaces. Additionally, the study links activation of known diguanylate cyclase-encoding pathways to cellulose expression and to signals encountered at the meniscus. Further significance stems from recognition of the consequences of fluid instabilities arising from surface production of cellulose for transport of water-soluble products over large distances

편도석 및 상악동석과의 비교 연구

학위논문(박사) -- 서울대학교대학원 : 치과대학 치의과학과, 2023. 2. 김성민.연구의 배경 및 목적 타석증은 악하선 및 이하선 부종과 통증의 주요 원인으로 1:15,000 ~ 1:30,000의 발병률을 보인다. 타석 형성에 대해 1) 유기적 핵심 이론: 박테리아, 이물질 또는 박리된 상피세포의 석회화; 2) sialomicrolith 이론: 일반적으로 악하선의 80% 존재하며, 3) 점액 표피 겔 이론: 고점도 뮤신의 석회화 등 많은 이론들이 제안되어 왔으나, 타석 형성의 정확한 매커니즘은 아직 알려지지 않았다. 또한 신장결석, 요결석, 담석 및 심혈관 석회화와 같은 인체의 병리학적 침착물의 특성화에 대한 많은 연구가 있지만, 타석의 초미세 구조 및 성분 구성에 대한 데이터는 매우 제한적이다. 본 연구는 편도석 및 상악동석과 비교하여 초미세 구조 및 화학 성분 분석을 수행하여 이들의 성장패턴을 파악하고, 타석 형성 및 그 합병증을 예방하기 위한 향후 중재 및 치료방법을 개발하기 위한 첫 단계가 되는 것을 목표로 하였다. 연구방법 23명의 환자로부터 얻은 25개의 검체를 타석(A), 편도석(B), 상악동석(C) 등 3개의 그룹으로 분류하였다. 검체는 헤마톡실린과 에오신 염색 (H&E) 하여 광학현미경 관찰 및 micro-CT로 상세한 특징을 분석하였고, 주사전자현미경 (SEM) 과 에너지분산X선분광법 (EDS) 분석을 위해 관심 영역 (ROI) 을 주변, 중간 및 코어 영역의 각 검체에 지정하여 국소 초미세 구조를 더 미세하게 분석하였다. 또한 각 그룹의 검체에 대해서 투과전자현미경 분석 (TEM) 을 수행하였다. 데이터 정규 분포는 Shapiro–Wilk테스트되었고, 그룹 간의 차이는 일원 분산 분석을 통해 검정되었다. 연구결과 마이크로 CT 분석 그룹 A는 턱밑샘과 귀밑샘 타석 모두에서 방사선밀도층과 방사선투과층이 교대로 형성된 양파껍질과 같은 층상구조가 관찰되었다. 그룹 A에서 11개의 타석 검체는 하나의 코어를 가지고 있는 반면, 하나의 타석은 여러 개의 코어를 가지고 있고, 다른 하나는 두 개의 코어를 가지고 있었으며, 또 다른 하나는 뚜렷한 코어가 관찰되지 않았다. 또한 그룹 A 타석은 구형의 타원형 또는 비대칭적인 모양을 가지고 있었으며, 타석의 코어는 주변 층에 비해 광물화 정도가 뚜렷하게 높거나 낮았다. 그룹 B는 동심 적층 패턴이 없는 균질한 구조를 보였다. 그룹C는 그룹A와 그룹B에 비해 내부 공극이 더 많은 치밀한 균질 구조를 보였다. 각 그룹은 total VOI (volume of interest) volume, object volume, percent object volume, total VOI surface, object surface, object surface/ volume ratio, object surface density, structure thickness, structure separation 및 total porosity (%)의 다른 형태학적 매개변수를 나타내었지만 통계적으로 유의한 차이는 발견되지 않았다. . 병리조직학적 분석 그룹 A는 유기물과 무기물의 동심원 라멜라 구조를 보였다. 코어에서 호산구성 특성을 보였고, 주변부에서 눈물방울 모양의 구형 구조의 적층 패턴을 보였다. 그룹 B는 섬유소 잔해와 염증 세포로 둘러싸인 성숙한 발달 단계를 보여주었다. 작은 타액선 관을 나타내는 편평 상피의 중심에서 덕트형 구조가 관찰되었고, 편도석 표면의 편평 상피는 편도선와 (tonsil crypt) 의 내벽을 향해 확장되는 것으로 나타났다. 그룹 C에서 병변은 캡슐화되지 않았으며 섬유성 골수강이 있는 균질한 층상골이 관찰되었다. 주사전자현미경(SEM) 분석 SEM 결과에서 그룹 A의 일반적인 구조는 광물화된 물질과 유기 물질이 번갈아 나타나는 동심원의 라멜라 구조가 관찰되었고, 재발된 타석 검체(A17)에서는 타석의 중심부에서 이물인diatomite 입자가 발견되었다. BSE 모드는 전자 후방 산란 확률이 시료 원소의 원자 질량에 비례하기 때문에 각 층의 서로 다른 화학 조성을 비교할 수 있게 하였다. 각 층의 미세 구조는 다양한 크기와 정도의 광물화된 구상체로 나사산으로 되어 있었다. 에너지분산X선분광법 (EDS) 분석 각 검체의 조성 분석 결과 그룹 A, B 및 C에서 칼슘(Ca), 탄소(C), 산소(O)의 높은 비율의 일관된 화학 성분을 보여주었다. 그룹 A는 그룹 C (14.78±10.29 wt% 및 5.76±4.52 at%) 에 비해 Ca Wt% (20.50±6.28 wt% and 16.74±44.08 at%) 의 수준이 유의하게 높았다 (p=0.003). 그룹C는 그룹 A (22.48±11.08wt%, 33.64±6.36at%) 에 비해 C그룹 (49.27±20.21wt%, 49.27±20.21at%) 에서 더 높았으나 유의한 차이는 없었다. O의 wt% 및 at%는 그룹 A (36.46±8.16 wt% 및 40.12±8.93 at%) 가 그룹 C (27.18±2.37 wt% 25.36±4.29 at%) 에 비해 유의하게 높았다 (p=0.002; p=0.019). 질소(N), 나트륨(Na), 규소(Si)를 포함한 다른 원소들은 두 그룹 모두에서 검출되었고, 구리(Cu), 불소(F), 인(P), 아연(Zn) 및 지르코늄(Zr)은 그룹 A에서만 발견되었으며, 그룹 C에서는 이러한 원소가 나타나지 않았다. 그룹 C (49.23±20.22wt%, 59.23±18.68at%) 는 그룹 A (22.36±4.70wt%, 32.46±5.74at%) 에 비해 그룹 C에서 유의하게 높았다 (p=0.00; p=0.035). 투과전자현미경 (TEM) 분석 그룹 A에서 이중막을 갖는 구형 구조물이 수포 내 석회화를 겪는 것으로 관찰되었고, 지질 소포와 손가락 모양의 구형 구조도 관찰되었다. 바늘 모양의 필라멘트 결정은 수산화인회석 구조를 시사하였고, 무기물의 수포내 및 수포외 침착이 관찰되었다. 결론 본 연구에서는 구강악안면외과 분야에서 발견되는 석회화의 다양한 유형 간 비교로 미세구조 및 구성 성분 연구를 수행하였다. 이 연구는 Micro-CT, SEM, EDS 및 TEM 분석을 통해 타석, 편도석 및 상악동석의 원소 조성이 서로 완전히 다른 미세 형태를 가지고 있음을 보여주었다. 타석은 고도로 광물화되거나 덜 광물화 된 코어를 가진 동심 적층 구조를 가지고 있는 반면, 편도석과 상악동석은 코어가 부족하였고, 상악동석은 층상골과 유사한 구조와 구성을 보였다. 이러한 결과는 각 유형의 석회화에서 서로 다른 석화 형성을 시사하며, 이는 각 유형의 석회화에서 서로 다른 치료 양식을 개발하는 근본적인 단계가 될 수 있다.Introduction Sialolithiasis is the primary etiology of submandibular and parotid gland swelling and pain, with an incidence of 1:15,000 to 1:30,000. Many theories have been proposed on sialolith formation (lithogenesis), such as 1) the organic core theory; 2) the sialomicrolith theory; and 3) the mucoepidermoid gel theory. However, the exact mechanism of sialolith formation is still unknown. Although, there are numerous studies on the characterization of pathological deposits in the human body such as the nephroliths, uroliths, gallstones, and cardiovascular calcifications, very limited data exist on the ultrastructural and elemental composition of sialolith. By performing a comparative ultrastructural and chemical composition analysis of sialolith, tonsillolith, and antrolith, the current study aimed to identify their growth pattern as the first step in developing intervention methods to prevent sialolith formation and its complications. Materials and methods Twenty-five specimens obtained from 23 patients were classified into three groups: sialolith (A), tonsillolith (B), and antrolith (C). The specimens were examined histopathologically and characterized in detail by micro-CT. For scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis, regions of interest (ROIs) were designated in each specimens peripheral, middle, and core regions to analyze the local ultrastructure at finer scales. Transmission electron microscopy (TEM) was also performed on specimens from each group. The datas normal distribution was tested by the Shapiro–Wilk test. The differences between groups were tested by one-way ANOVA. p < 0.05 was considered statistically significant. Results Micro-CT analysis Group A showed onion skin-like layered structure with alternating radiodense and radiolucent layers in both submandibular and parotid gland sialolith. In group A, 11 sialolith specimens had a single core, while one sialolith had multiple cores, one sialolith had two cores, and one sialolith with no distinct core. The sialolith cores in group A displayed either distinctively higher or lower degree of mineralization compared to the surrounding layers. The sialolith had nearly spherical oval, or asymmetrical shapes Group B, the tonsillolith, had a homogeneous structure without concentric laminated pattern. The group C specimen revealed a compact homogenous structure, with more internal voids compared to that of group A and group B. Although each group showed different morphometric parameters of total VOI (volume of interest) volume, object volume, percent object volume, total VOI surface, object surface, object surface/ volume ratio, object surface density, structure thickness, structure separation, and total porosity (percent), no statistically significant differences were found. Histopathological analysis Group A showed concentric lamellar structure with organic and inorganic substances. A laminated, teardrop-shaped, globular structure was present at the periphery. Group B showed a duct-like structure present at the center of squamous epithelium indicative of the minor salivary gland duct. Squamous epithelium on the surface of the tonsillolith was noted to extend toward the lining of the tonsillar crypt. In group C, the lesion was not encapsulated and showed a homogeneous lamellar bone with fibrous marrow cavities. SEM analysis The general architecture of Group A in SEM findings was a concentric lamellar structure with alternating mineralized and organic material. A diatomite was found at the core of the sialolith in a recurrent stone (A17). The BSE mode allowed for the comparison of the different chemical composition in each layer as the probability of electron backscatter was proportional to the atomic mass of the specimen element. The fine structure of each layer was threaded with mineralized globules. EDS analysis The compositional analysis of each specimen demonstrated a high fraction of consistent components, calcium (Ca), carbon (C), and oxygen (O), in groups A, B, and C. Group A had a significantly higher level of Ca wt% (20.50 ± 6.28 wt% and 16.74 ± 44.08 at%) compared to that of Group C (14.78 ± 10.29 wt% and 5.76 ± 4.52 at%) (p = 0.003). The C level was higher in group C (49.27±20.21 wt% and 49.27±20.21 at%) compared to that of group A (22.48±11.08 wt% and 33.64±6.36 at%), although no significant difference was found The wt% and at% of O was significantly higher in group A (36.46 ± 8.16 wt% and 40.12 ± 8.93 at%), compared to that of group C (27.18 ± 2.37 wt% 25.36 ± 4.29 at%) (p = 0.002; p = 0.019, respectively). Other elements including nitrogen (N), sodium (Na), and silicon (Si) were detected in both groups. Copper (Cu), fluorine (F), phosphorus (P), zinc (Zn), and zirconium (Zr) were found only in group A, while group C did not show these elements. The C level was significant higher in group C (49.23 ± 20.22 wt% and 59.23 ± 18.68 at%), compared to that of Group A (22.36 ± 4.70 wt% and 32.46 ± 5.74 at%) (p = 0.00; p = 0.035, respectively). TEM analysis In group A, globular structures with a double membrane were detected undergoing intra-vesicular calcification. Lipid vesicles and finger-like globular structures were also detected. Needle-like filamentary crystals suggested hydroxyapatite structure. Intra-vesicular and extra-vesicular deposition of inorganic matter was seen. Group B had stratified squamous epithelium in its peripheral area. Bacteria were present in the middle layer and needle-like crystals were seen in the core region. In the outer layer of the group C an osteoblastic rimming was observed. The middle region of the specimen was mainly composed of dense, mature, and predominantly lamellar bone. The core region had no Haversian canals and fibrous component. Conclusion This was a new comparative, ultrastructural and elemental study of different types of calcifications found in the Oral and Maxillofacial Surgery field. The study demonstrated that sialolith, tonsillolith, and antrolith have completely different micromorphology and elemental composition as determined by micro-CT, SEM, EDS, and TEM analysis. The sialolith had a concentric laminated structure with highly mineralized or less mineralized core, while tonsillolith and antrolith lacked a core. Antrolith showed a structure and composition similar to that of a lamellar bone. These results suggest a different lithogenesis pattern in each type of calcification. This could be the fundamental step in developing different treatment modalities for each type of calcification.I. Introduction 1 I.1. Sialolith, tonsillolith and antrolith formation (lithogenesis) 1 I.2. Sialolithiasis 4 II. Materials and Methods 7 II.1. Sialolith, tonsillolith and antrolith specimen collection 7 II.2. Specimen selection and grouping 8 II.3. Micro-CT analysis 8 II.4. Histopathological analysis 9 II.5. Sialolith, tonsillolith and antrolith analysis by SEM 9 II.6. Chemical composition analysis by EDS 11 II.7. TEM experiment 11 II.8. Statistical analysis 12 III. Results 13 III.1. Patient characteristic and demographic data 13 III 2. The sialolith, tonsillolith and antrolith specimen data 13 III.3. Micro-CT analysis sialolith, tonsillolith and antrolith 14 III.4. Histopathological findings 15 III.5. SEM findings of sialolith, tonsillolith and antrolith 17 III.6. Chemical composition of sialolith, tonsillolith, and antrolith 21 III.7. TEM analysis 23 IV. Discussion 26 V. Conclusion 33 References 35 Tables 40 Figures and Figure legends 49 Abstract in Korean 86박

Physical, chemical and antimicrobial properties evaluation of a resin based material for braces cementation containing different concentrations of quaternary ammonium

Orientadores: Flávio Henrique Baggio Aguiar, Ubirajara Pereira Rodrigues FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A fixação de acessórios ortodônticos na cavidade bucal favorece maior acúmulo de biofilme dental. Para minimizar o risco do desenvolvimento de lesões cariosas, materiais utilizados para fixação destes acessórios acrescidos de grupamentos químicos funcionais com efeito antimicrobiano têm sido desenvolvidos. Desta forma, os objetivos deste estudo foram: 1) Sintetizar e caracterizar um organossilano modificado por amônias quaternárias (ORMOSIL-QAMS); 2) Avaliar as propriedades físico-químicas da resina Transbond XT Light Cure Adhesive (3M Unitek) acrescida de 10% e 15% em massa de ORMOSIL-QAMS e 3) Avaliar o efeito antimicrobiano do acréscimo de 10% e 15%, em massa, de ORMOSIL-QAMS à resina Transbond XT ou aplicando-o como material de recobrimento. O ORMOSIL-QAMS foi sintetizado por uma reação de hidrólise e condensação (sol-gel). Na primeira etapa, alcoxissilanos contendo amônias quaternárias foram obtidos. Em seguida, uma rede silicato englobando os alcoxissilanos foi criada, levando à formação do ORMOSIL-QAMS. O produto da síntese foi caracterizado por espectroscopia de infravermelho e fluorescência de Raios-X. Os testes de grau de conversão (DC) (n=7); sorção de água (Wsp) (n=9); solubilidade (Wsl) (n=9); resistência coesiva (UTS) (n=10) e resistência ao cisalhamento (SBS) (n=10) foram realizados após 24 h da confeccção dos espécimes para os grupos: T ¿ Resina Transbond XT Light Cure Adhesive; T10% - Resina Transbond XT contendo 10%, em massa de ORMOSIL-QAMS; T15% - Resina Transbond XT contendo 15% em massa, de ORMOSIL-QAMS. Para avaliar o efeito antimicrobiano um grupo de estudo foi adicionado: TC ¿ Resina Transbond XT recoberta por duas camadas de ORMOSIL-QAMS. A formação de biofilme de Streptococcus mutans UA159 foi realizada em corpos-de-prova de resina correspondente a cada grupo, utilizando meio de cultura Brain Heart Infusion (BHI) com 1% de sacarose por 24 h a 37°C e 5% de CO2. Os dados de propriedades físico-químicas foram submetidos à análise ANOVA e Tukey pós-teste (?=0,05). Os dados obtidos do ensaio de formação de biofilme foram submetidos à análise não paramétrica Kruskall-Wallis e pós-teste Student-Newman-Keuls (?=0,05). A espectroscopia por infravermelho confirmou a presença da rede silicato e dos grupos de amônia quaternária. A fluorescência de Raios-x detectou a presença dos elementos silício e iodo. O DC dos compósitos não diferiu (p>0,05). Quanto maior a quantidade de ORMOSIL-QAMS inserido na resina composta, menores taxas de sorção de água e solubilidade foram observadas (p0,05). Apenas a aplicação do ORMOSIL-QAMS como material de recobrimento apresentou atividade antimicrobiana. Concluiu-se que a adição de ORMOSIL-QAMS reduziu a resistência coesiva e ao cisalhamento da resina para fixação de bráquetes. No entanto, a utilização como material de resobrimento de superfície promoveu redução significativa da formação biofilme 24 h de S. mutansAbstract: Despite the great need and applicability of orthodontic treatment, most of them include cementation of orthodontic brackets and other metal accessories on tooth surface. Recently, the chemical composition of dental materials has been explored to obtain some specific properties. With regard to composite resins for bonding fixed appliances in orthodontics, antibacterial property is desirable due to cleaning difficulties and biofilm accumulation. Thus the aim of this study was to develop an organosilane with quaternary ammonium group (ORMOSIL-QAMS) and assess chemical and physical properties of Transbond XT Light Cure Adhesive containing 10 wt% and 15 wt% ORMOSIL-QAMS. Furthermore, the study aimed to evaluate its antimicrobial effect incorporated (10 wt% and 15 wt%) to Transbond XT Light Cure Adhesive (3M Unitek) or used as a coating material. A reaction of hydrolysis and condensation (sol-gel) was employed to develop ORMOSIL-QAMS. On the first step, alkoxysilanes containing quaternary ammonium group were obtained. Then a silicate network wrapping the quaternary ammonium was created, leading to the formation of ORMOSIL-QAMS. Synthesis product was characterized by infrared spectroscopy and X-Ray fluorescence. Degree of conversion (DC) (n=7); water sorption (Wsp) (n=9); solubility (Wsl) (n=9); ultimate tensile strength (UTS) (n=10) and shear bond strength (SBS) (n=10) tests were done after 24 h of storage, for the following groups: T ¿ composite resin Transbond XT; T10% - Transbond XT containing 10 wt% of ORMOSIL-QAMS; T15% - Transbond XT containing 15 wt% of ORMOSIL-QAMS. For antibacterial properties one group was added: TC ¿ Transbond XT covered by two layers of ORMOSIL-QAMS. Streptococcus mutans UA159 were grown for 24 h in Brain-Heart-Infusion (BHI) supplemented with 1% sucrose at 37 °C and 5% CO2. Physico-chemical properties data were subjected to ANOVA and Tukey¿s post hoc test (?=0.05). The antibacterial test values were subjected to non-parametric Kruskal-Wallis and Student-Newman-Keuls test (? = 0.05). The DC did not differ between groups (p>0.05). Water sorption and solubility decreased as the percentage of ORMOSIL-QAMS inserted increased (p0.05). Only the coating application resulted in less S. mutans biofilm formation in 24 hours (p<0.05). Based on this study it is possible to conclude that incorporating ORMOSIL-QAMS to Transbond XT adversely affected shear bond strength and ultimate tensile strength properties. Additionally, ORMOSIL-QAMS presented the expected antimicrobial activity when applied as coating on the sample surface, diminishing S. mutans biofilm formation considerablyMestradoDentísticaMestra em Clínica Odontológica2013/15518-5FAPES

Development and characterization of a stable adhesive bond between a poly(dimethylsiloxane) catheter material and a bacterial biofilm resistant acrylate polymer coating

Catheter associated urinary tract infections (CA-UTIs) are the most common health related infections world wide, contributing significantly to patient morbidity and mortality and increased health care costs. To reduce the incidence of these infections, new materials that resist bacterial biofilm formation are needed. A composite catheter material, consisting of bulk PDMS coated with a novel bacterial biofilm resistant polyacrylate (EGDPEA–co-DEGMA) has been proposed. The coated material shows excellent bacterial resistance when compared to commercial catheter materials but delamination of the coatings under mechanical stress presents a challenge. In this work, the use of oxygen plasma treatment to improve the wettability and reactivity of the PDMS catheter material and improve adhesion with the EGDPEA–co-DEGMA coating has been investigated. Argon Cluster 3D-imaging Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has been used to probe the buried adhesive interface between the EGDPEA–co-DEGMA coating and the treated PDMS. ToF-SIMS analysis was performed in both dry and frozen-hydrated states and results were compared to mechanical tests. From the ToF-SIMS data we have been able to observe the presence of PDMS, silicates, salt particles, cracks and water at the adhesive interface. In the dry catheters, low molecular weight PDMS oligomers at the interface were associated with poor adhesion. When hydrated, the hydrophilic silicates attracted water to the interface and led to easy delamination of the coating. The best adhesion results, under hydrated conditions, were obtained using a combination of 5 min O2 plasma treatment and silane primers. Cryo-ToF-SIMS analysis of the hydrated catheter material showed that the bond between the primed PDMS catheter and the EGDPEA–co-DEGMA coating was stable in the presence of water. The resulting catheter material was resisted Escherichia coli and Proteus mirabilis biofilm colonization by up to 95 % compared with uncoated PDMS after 10 days of continuous bacterial exposure and had the mechanical properties necessary for use as a urinary catheter