Dispositifs de délivrance de principes actifs pour des applications ophtalmologiques

Protection Provided by a Gabexate Mesylate Thermo-Sensitive In Situ Gel for Rats with Grade III Pancreatic Trauma

Background/Aims

This study investigated the protection provided by gabexate mesylate thermo-sensitive in-situ gel (GMTI) against grade III pancreatic trauma in rats.

Methods

A grade III pancreatic trauma model with main pancreatic duct dividing was established, and the pancreas anatomical diagram, ascites, and serum biochemical indices, including amylase, lipase, C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α), were examined. The pancreas was sliced and stained with hematoxylin eosin and subjected to terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining.

Results

Ascites, serum amylase, lipase, CRP, IL-6, and TNF-α levels were significantly increased in the pancreas trauma (PT) groups with prolonged trauma time and were significantly decreased after GMTI treatment. The morphological structure of the pancreas was loose, the acinus was significantly damaged, the nuclei were irregular and hyperchromatic, and there was inflammatory cell invasion in the PT group compared to the control. After GMTI treatment, the morphological structure of the pancreas was restored, and the damaged acinus and inflammatory cell invasion were decreased compared to the PT group. Moreover, the cell apoptosis index was significantly increased in the PT group and restored to the same levels as the control group after GMTI treatment.

Conclusions

GMTI, a novel formulation and drug delivery method, exhibited specific effective protection against PT with acute pancreatitis therapy and has potential value as a minimally invasive adjuvant therapy for PT with acute pancreatitis.

Liposomes for intravitreal drug delivery: a state of the art

Intravitreal administration of drugs has raised a large interest during the last two decades improving the treatment of infectious diseases of the posterior segment of the eye or edematous maculopathies. This route of administration allows achieving high drug concentrations in the vitreous and avoiding adverse effects resulting from systemic administration. However, many drugs are rapidly cleared from the vitreous humor; therefore, to reach and to maintain effective therapy, repeated administrations are necessary. Unfortunately, frequent intravitreal injections increase the risk of endophthalmitis, damage to lens, retinal detachment. Moreover, some drugs provoke a local toxicity at their effective dose inducing side-effects and possible retinal lesions. This is the reason why new drug delivery systems, among which liposomes, have been developed to improve the intravitreal administration of drugs. Liposomes can reduce the toxicity and increase the residence time of several active molecules in the eye. In vivo, they can protect poorly-stable drugs such as peptides and nucleic acids from degradation. Successful reports have shown their potential for improving the treatment of retinitis induced by cytomegalovirus in human and more recently for the treatment of uveitis in rats. Moreover, recent preliminary studies about the trafficking of liposomes in ocular tissues and fluids following intravitreal injection attempted to elucidate their fate. All the data discussed in this review support the large interest raised by these colloidal carriers for intravitreal drug delivery.

[Potential of liposomes for the intravitreal injection of therapeutic molecules]

Intravitreal administration has been widely used since 20 years and has been shown to improve the treatment of diseases of the posterior segment of the eye with infectious origin or in edematous maculopathies. This route of administration allows to achieve high concentration of drug in the vitreous and avoids the problems resulting from systemic administration. However, two basic problems limit the use of intravitreal therapy. Many drugs are rapidly cleared from the vitreous humor; therefore, to reach and to maintain effective therapy repeated injections are necessary. Repeated intravitreal injections increase the risk of endophthalmitis, damage to lens, retinal detachment. Moreover, some drugs provoke a local toxicity at their effective dose inducing side-effects and possible retinal lesions. In this context, the development and the use of new drug delivery systems for intravitreal administration are necessary to treat chronic ocular diseases. Among them, particulate systems such as liposomes have been widely studied. Liposomes are easily injectable and permit to reduce the toxicity and to increase the residence time of several drugs in the eye. They are also able to protect in vivo poorly-stable molecules from degradation such as peptides and nucleic acids. Some promising results have been obtained for the treatment of retinitis induced by cytomegalovirus in human and more recently for the treatment of uveitis in animal. Finally, the fate of liposomes in ocular tissues and fluids after their injection into the vitreous and their elimination routes begin to be more known.