Figure 3.

Computational model of eMSC and LA.

Notes: Using HPLC data from the study by Maguire et al³⁹ and a half-life of 2.7 hours,⁴² a MATLAB explicit finite difference method was generated to determine the concentration of drug in the presence of eMSCs at a given time point. By 8 hours, <1% of the initial dose of 1 mM from the construct reached the cells, whereas 18.06% of the bolus drug reached the cells in the same time period. Using the construct, <1% was present at any time point for the total 96 hours, yielding an overall total accumulation of 8.1% assuming no internalization of the drug. however, as the bupivacaine is constantly degrading over time, we were more concerned with the concentration of bupivacaine that reached the cells during any 8-hour time period.

Abbreviations: eMSC, encapsulated mesenchymal stromal cell; LA, local anesthetic.