Topical anesthetic and pain relief using penetration enhancer and transcriptional transactivator peptide multi-decorated nanostructured lipid carriers

Figures & data

Figure 1. Synthesis of PB-PEG-DSPE. PB-PEG-DSPE was synthesized by conjugating PB with the amido groups of DSPE-PEG through amide formation.

Figure 2. Scheme graph and transmission electron microscope image of TAT/PB LID NLC. TAT/PB LID NLC was prepared by solvent diffusion method. The morphology and size of TAT/PB LID NLC was visualized by a transmission electron microscope.

Figure 3. Storage stability of NLC. The NLC showed no significant change on size (A), PDI (B), EE (C), and DL (D) during the storage at 2–8 °C for a period of 90 days. Data presented as mean ± standard derivation (n = 6).

Table 1. Characterization of NLC.

Formulation	Particle size (nm)	PDI	Zeta potential (mV)	EE (%)	DL (%)
LID NLC	115.3 ± 3.6	0.13 ± 0.01	−29.3 ± 2.6	91.6 ± 2.8	12.3 ± 1.5
TAT LID NLC	152.7 ± 4.8	0.16 ± 0.02	−21.2 ± 1.9	90.1 ± 3.1	9.4 ± 0.9
PB LID NLC	141.1 ± 3.9	0.14 ± 0.02	−27.6 ± 2.9	89.5 ± 2.9	8.9 ± 0.7
TAT/PB LID NLC	153.6 ± 4.3	0.15 ± 0.03	−20.7 ± 2.3	88.7 ± 3.3	8.1 ± 0.8
TAT/PB NLC	154.1 ± 4.7	0.16 ± 0.03	−22.4 ± 2.5

Data represents the mean ± SD, n = 3.

Figure 4. In vitro drug release profiles of NLC. Dialysis method was applied to evaluate the in vitro drug release of LID from the NLC. Data presented as mean ± standard derivation (n = 6).

Figure 5. In vitro percutaneous penetration effect of NLC. In vitro skin permeation study was carried out in Vertical Franz-type diffusion cells with cross-sectional area of 5.93 cm² and 7.0 mL cell volume. Data presented as mean ± standard derivation (n = 6). *p < .05.

Figure 6. In vivo anesthetic pain relief effect was assessed by the tail-flick test in rats. A harmful heat stimulus was applied to the back surface of the tail by a focused radiant heat source. Percentage of the maximum possible effect (MPE) was applied to express the anesthetic pain relief effect. Data presented as mean ± standard derivation (n = 8).

Figure 7. In vivo analgesia duration test was applied by electrical stimulation testing in mice. A current generator was used to measure the analgesic effect by the vocal response to electrical stimulation (starting at 1 mA and increasing to a maximum of 8 mA) directly over the skin of the abdomen at the injection site.