Q pod dispenser

Amoxicillin trihydrate was bought from TCI (Tokyo, Japan) and Eudragit^® L100 was acquired from Evonik Industries (Essen, Germany). Dibutyl sebacate, isopropanol and potassium phosphate monobasic for the HPLC mobile phase were purchased from Sigma Aldrich (St. Louis, MO, USA). Methanol was bought from VWR International (Radnor, PA, USA).
The negative epoxy based photoresist SU-8 was used for production of microcontainers. Formulations with two different viscosities were used (i.e., SU-8 2035 and 2075) and the cross-linked structures were developed in Developer mr-Dev 600. Resist and developer were purchased from Micro Resist Technology GmbH (Berlin, Germany). Single-side polished ø100 mm Si substrates with a thickness of 525 µm were acquired from Topsil Globalwafers A/S (Frederikssund, Denmark).
For the phosphate buffered saline (PBS) used in the in situ perfusion studies, sodium chloride, potassium chloride, sodium phosphate dibasic and potassium phosphate monobasic were purchased from Scharlab (Barcelona, Spain). Animals were from Charles River Laboratories (Quebec, QC, Canada). Sylgaard 184 silicone elastomer kit was purchased from Dow Chemical (Midland, MI, USA). Ultrapure water used throughout the studies was obtained from a Q-POD^® dispenser (Merck Millipore, Burlington, MA, USA).

Chemicals were purchased from Sigma-Aldrich and Thermo Scientific. The principal solvent in which analytes were dissolved was ultrapure water delivered from a Merck Q-POD dispenser. Solutions without NRs were passed through a 0.2 µm Minisart syringe filter and dilutions were performed with Gilson P2L, P20L, and P1000L pipettes. Each microspherical cavity was reflowed from a Corning SMF-28 Ultra, single-mode telecommunications fibre by CO₂ laser light absorption. Surface tension during heating yielded a circularly symmetric cavity structure with a smooth dielectric interface. Mechanical stabilisation of the suspended microcavity was provided by prior insertion into a Thorlabs CF126-10 ceramic ferrule, which was then secured to an aluminium holder fixed to a three-axis translation stage. The diffusion-limited sample volume of 300–500 µL was enclosed by a glass window, N-SF 11 prism face, and sandwiched polydimethylsiloxane (PDMS) basin.