To compare the influence of fluid on carboplatin elution, and assess the feasibility of ultrafiltration (UF) probe sampling
20 samples of 5 mg carboplatin in 1.0 mL 30% poloxamer 407 eluting in Dulbecco’s phosphate-buffered saline (DPBS) or canine plasma and 6 samples of UF probe sampling in 0.01 mg/mL carboplatin in DPBS or plasma.
Carboplatin-gel specimens in dialysis tubing (12- to 14-kDa pores) were placed in 100 mL of DPBS or canine plasma (37 °C and 600 rpm stirring) in a nonlidded and lidded experiment. Samples were collected in decreasing frequency for 96 hours. The 0.01-mg/mL carboplatin solutions in DPBS and plasma were sampled 6 times by UF probe (30-kDa pores) or direct aspiration. Platinum was measured using inductively coupled plasma mass spectrometry.
High fluid evaporation was noted in the nonlidded but not the lidded experiment. A burst release was seen in plasma (first 2 hours) and DPBS (first 5 hours) with the highest hourly increase in the first hour in both DPBS (6,040 ppb/h) and plasma (2,612 ppb/h), with no further increase after the first 22 hours. Platinum content in the specimens was higher at 96 hours than the surrounding fluid. Higher platinum concentrations were measured by both direct and UF probe sampling in DPBS than in plasma.
Platinum concentrations measured in DPBS were higher than in plasma, but elution patterns were similar. Ultrafiltration probes can be used to sample platinum in vitro and could be used in vivo to measure local unbound Pt tissue concentrations in local chemotherapy delivery.
To determine and compare the rate, pattern, and completeness of silver nanoparticle (AgNP) elution in vitro over 7 days from 3 carrier media in PBSS.
AgNPs in calcium sulfate hemihydrate (CSH) beads, poloxamer 407 gel, and a gelatin sponge.
Three carrier media were used to create constructs containing AgNPs (8,500 ng). All constructs were submerged in PBSS and stored at 38°C for 7 days. Samples were collected after 2, 6, 12, 18, 24, 36, 48, 72, 96, 120, 144, and 168 hours, and AgNP concentration was measured with inductively coupled plasma mass spectrometry. Constructs were tested in quadruplicate.
Sustained release of AgNPs was seen from all constructs for a minimum of 72 hours. Release from all constructs was incomplete, with an initial burst during the first 24 hours followed by a time-dependent decrease in elution rate for up to 168 hours. A mixed-effects model showed a significant difference in AgNP release over time (P < .001) and among media (P < .001). AgNP–gel constructs released the largest quantity of AgNPs (8,401.02 ng [98.84%]), followed by AgNP–sponge constructs (1,503.45 ng [17.69%]). Release from AgNP–CSH bead constructs was 87.824 ng (1.03%), with no additional release after 72 hours.
Sustained release of AgNPs is possible in vitro, but efficacy against bacterial infections needs to be investigated prior to clinical use.