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.