2.13. Ofloxacin release behavior
The measurement and calculation methods are based on our previous reports33. Briefly, 1 mL of OHH NPs solution with the concentration of 100 μg/mL with/without HAase was irradiated by 808 nm NIR laser at power density of 1 W/cm2 for 5 min. Then, 200 μL of solution was taken out every 30 min and the solution was immediately centrifuged at 13,000 rpm for 10 min. Finally, the concentration of ofloxacin of the supernatant was measured by UV-Vis spectrophotometer. The drug loading capacity and entrapment efficiency of the OHH NPs were calculated as follows:
Loading capacity (%) = (MT −MU) /MP ×100 %
where MT represents the total mass of drug, MU represents the mass of the unencapsulated drug, and MP represents the mass of PB and HMPB.