Mechanism of Propofol-Lidocaine Hydrochloride Nano-Emulsion on Retinal Ganglion Cytopathic Effect in Diabetic Rats

The study drew attention to the influence mechanism of propofol and lidocaine hydrochloride nanoemulsion (NE) in the retinal ganglion cell pathology in diabetic rats. Specifically, the propofollidocaine hydrochloride NE was prepared using the emulsification method. The microscope and laser particle size analyser were used to observe the morphology and particle size of NE, respectively. Also, the viscosity of the NE and the recovery rate of the main ingredient were explored. 45 adult male Wistar rats were randomly divided into control group (PBS control), model group (diabetes model), and test group (diabetes model+propofol-lidocaine hydrochloride NE), with 15 rats in each group. The three groups were compared for the blood glucose, body weight, TNF-α and IL-1β mRNA levels in retinal tissue, and the number and apoptosis rate of ganglion cells. It was found that the average particle size of the NE was 89.76 nm, the maximum absorption wavelength was 280.0 nm, and the viscosity was 106.49 N/m/s. The average recovery rate of propofol in NE was 99.91%, and that of lidocaine hydrochloride was 99.80%. At 12th week after modeling, the blood glucose of the test group was lower versus the model group (P < 0.05); the blood glucose and body weight of rats in the control group were lower than those in the other two groups (P < 0.001). The test group exhibited lower mRNA levels of TNF-α and IL-1β and apoptosis index of retinal ganglion cells versus the model group (P < 0.05). The model group showed a lower number of retinal ganglion cells versus the other two groups (P < 0.05). It was inferred that propofol-lidocaine hydrochloride NE of a small particle size and good syringeability can notably reduce blood glucose, TNF-α and IL-1β mRNA levels, and retinal ganglion cell apoptosis index, and at the same time increase the number of retinal ganglion cells.

Screening of Anaesthetics in Adult Zebrafish (Danio rerio) for the Induction of Euthanasia by Overdose

Zebrafish are often euthanized by overdose of anaesthesia. However, fish may have aversion towards some anaesthetics, and protocol efficacy varies between species. Using wild type adult Danio rerio, we assessed time to loss of opercular beat, righting, and startle reflexes during induction of anaesthetic overdose by either tricaine (0.5 g/L or 1 g/L), benzocaine (1 g/L), 2-phenoxyethanol (3 mL/L), clove oil (0.1%), isoeugenol (540 mg/L), lidocaine hydrochloride (1 g/L), or etomidate (50 mg/L). Initial screening demonstrated that benzocaine and buffered lidocaine hydrochloride achieved the fastest loss of reflexes. The rapid induction times were confirmed when retesting using larger batches of fish. The fastest induction was obtained with 1 g/L lidocaine hydrochloride buffered with 2 g/L NaHCO3, in which all adult zebrafish lost reflexes in less than 2 min. Next, we monitored signs of distress during benzocaine or buffered lidocaine hydrochloride overdose induction. The results indicated that buffered lidocaine hydrochloride caused significantly less aversive behaviors than benzocaine. Finally, we tested several buffers to refine the lidocaine hydrochloride immersion. The most efficient buffer for euthanasia induction using 1g/L lidocaine hydrochloride was 2 g/L NaHCO3 with 50 mL/L 96% ethanol, inducing immobility in less than 10 s and with only 2% of adult zebrafish displaying aversive behaviors during treatment.

Factors Affecting Gelation of Lidocaine Hydrochloride-Loaded Polyelectrolyte Complex Thermosensitivity Gel for Dry Socket Treatment

Dry socket disease, a pocket wound caused by the tooth extraction that resulted in severe acute pain which requires a topical analgesic with rapidly pain reduction and suppress the pain until the wound healed. This study aimed to investigate factors affecting gelation temperature and gelation time of lidocaine hydrochloride (LH)-loaded polyelectrolyte complex (PEC) thermosensitivity gel for treating dry socket wound. The first factor was investigated the effects of the ratio of three different types of polymers as chitosan (CS), hyaluronic acid (HA) and poloxamer407 (P407) on the phase transition caused by temperature. The second factor was examined the effects of gel preparation methods. The results showed that increasing concentration of the cationic polymer as CS induced the separation of the solution to gel (sol-to-gel) system due to the charge of CS and the charge of PEC. The ratio of HA:P407 affected the gel forming which high concentration of P407 reduced the gelation temperature while low concentration of HA disturbed the sol-to-gel state causing coagulation. The viscosity, spreadability, and swelling were significantly increased due to the concomitant increased in each polymer, HA and P407. The particle of the formulation observed under microscope was found to be less than 1 µm. Phase inversion from sol-to-gel was found after a min at 23°C. Since gelation temperature of the purposed formula is supposed to form gel below 37°C within a short period of injection. The results of the study indicate the suitable sol-to-gel forming in the appropriate temperature and time which should be used for further investigation in the efficacy and safety.