Инфекционные заболевания: профилактика и контроль

Bacterial Diseases 2019: Drug delivery by tattooing to treat cutaneous leishmaniasis

Stef Stienstra

Leishmaniasis is a vector-borne disease that is caused by obligate intra-macrophage protozoa of the Leishmania species. Leishmaniasis can cause different clinical syndromes, including Cutaneous Leishmaniasis (CL) in which the patient generally presents with one or several ulcer(s) or nodule(s) on the skin, resulting from the infection of phagocytic cells located in the dermis. It often results into severe scar tissue in the skin. Most of the twelve million people infected with Leishmania worldwide are CL cases, a 1.5 million new cases occur annually. WHO has a program to develop new treatments for cutaneous leishmaniasis. This study establishes a proof-of-concept that a tattoo device can target intra-dermal drug delivery against Cutaneous Leishmaniasis (CL). The selected drug is Oleylphosphocholine (OlPC) formulated as liposomes, particles known to be prone to macrophage ingestion. First is shown that treatment of cultured Leishmania-infected macrophages with OlPC-liposomes results in a direct dose-dependent killing of intracellular parasites. Based on this, in vivo efficacy is demonstrated using a 10-day tattooing-mediated treatment in mice infected with L. major and L. mexicana. In both models this regimen results in rapid clinical recovery with complete regression of skin lesions by Day 28. Parasite counts and histopathology examination confirm high treatment efficacy at the parasitic level. Low amount of drug required for tattooing combined with fast clinical recovery may have a positive impact on CL patient management. This first example of tattoo-mediated drug delivery could open to new therapeutic interventions in the treatment of skin diseases. This study demonstrates that the use of a tattoo instrument for drug delivery is possible in the treatment of cutaneous leishmaniasis and that this method can successfully eliminate intracellular parasites at the site of infection. After showing that the selected drug Oleylphosphocholine (OlPC) formulated as liposomes could efficiently reach intracellular parasites when in contact with infected macrophages, the activity of the drug was compared in vivo in mouse models of old (L. major) and new world (L. mexicana) leishmaniasis. Three routes of administrations of the same drug formulation were investigated: Systemic (IP) administration, topical administration as a drop and administration via the tattoo instrument. Evaluation parameters included clinical (lesion sizes) and parasitological parameters (burdens) using quantitative and qualitative methods. In all experiments, the tattooing delivery procedure was the most efficacious at both the clinical and parasitological levels.

 

Cutaneous leishmaniasis is the most widely recognized type of leishmaniasis influencing people. It is skin contamination brought about by a solitary celled parasite that is transmitted by the chomp of a phlebotomine sandfly. There are around twenty types of Leishmania that may cause cutaneous leishmaniasis. This sickness is viewed as a zoonosis (an irresistible illness that is normally transmissible from creatures to people), except for Leishmania tropica — which is frequently an anthroponotic malady (an irresistible infection that is normally transmissible from people to vertebrate creatures).

Post-kala-azar dermal leishmaniasis (PKDL) is a repeat of kala-azar that may show up on the skin of influenced people months and as long as 20 years in the wake of being mostly rewarded, untreated or even in those considered satisfactorily rewarded. In Sudan, they can be shown in up to 60% of rewarded cases. They show as hypopigmented skin injuries, (for example, macules, papules, knobs), or facial redness. In spite of the fact that any life form causing kala-azar can prompt PKDL, it is normally connected with Leishmania donovani which gives diverse ailment designs in India and Sudan. In the Indian variation, knobs expand with time and structure plaques yet infrequently ulcerate, however knobs from the African assortment regularly ulcerate as they progress. Nerve association is regular in African assortment however uncommon in the Indian subcontinent. Histology shows a blend of incessant provocative cells; there can be macrophage or epithelioid granuloma. Parasite fixation isn't predictable among examines, maybe reflecting low affectability of demonstrative strategies utilized in before passages.

 

The current way to deal with finding includes 1. show of the parasite by microscopy, in vitro culture or creature immunization; 2. immunodiagnosis of parasite antigen; 3. location of parasite DNA in tissue. Fresher PCR based apparatuses have higher affectability and explicitness. Rise of PKDL has been accounted for in HIV influenced people and may turn into an issue in the future.

Sodium stibogluconate alone or in blend with rifampicin is utilized for the treatment of PKDL for a long course of as long as 4 months. Consistency can be an issue for such a long course. Mucocutaneous leishmaniasis is a particularly upsetting type of cutaneous leishmaniasis since it produces dangerous and distorting injuries of the face. It is regularly brought about by Leishmania braziliensis, yet cases brought about by L. aethiopica have likewise been portrayed. Mucocutaneous leishmaniasis is extremely hard to treat. Treatment includes the utilization of pentavalent antimonial mixes, which are profoundly harmful (normal reactions incorporate thrombophlebitis, pancreatitis, cardiotoxicity, and hepatotoxicity) and not exceptionally viable. For instance, in one investigation, regardless of treatment with high portions of sodium stibogluconate for 28 days, just 30% of patients remained ailment free at a year development. Indeed, even in those patients who accomplish an obvious fix, the same number of as 19% will backslide. A few medication blends with immunomodulators have been tried, for instance, a mix of pentoxifylline (inhibitor of TNF-α) and a pentavalent antimonial at a high portion for 30 days in a little scope (23 patients) randomized fake treatment controlled examination from Brazil accomplished fix paces of 90% and decreased chance to fix, an outcome that ought to be deciphered circumspectly considering inalienable constraints of little scope contemplates. In a prior little scope (12 patients) study, the expansion of imiquimod demonstrated promising outcomes that need yet to be affirmed in bigger preliminaries. Promastigotes of Leishmania are transmitted to human skin by the chomp of a sandfly. Leishmania at that point attacks human macrophages and recreates intracellularly. A raised, red injury creates at the site of the nibble (frequently weeks or now and then years subsequently). The sore at that point ulcerates and may turn out to be optionally contaminated with microscopic organisms. In numerous species (for instance, L. major) the sore frequently unexpectedly mends with atrophic scarring. In certain species (for instance, L. braziliensis) the injury may suddenly recuperate with scarring yet then return somewhere else (particularly as ruinous mucocutaneous sores). Sores of other Leishmania species may unexpectedly recuperate and afterward return as satellite sores around the site of the first injury, or along the course of lymphatic drainage.

A few animal categories will in general reason cutaneous leishmaniasis (e.g., L. major and L.tropica), while a few animal groups will in general reason instinctive leishmaniasis (e.g., L. infantum and L. donovani), however rising examination (because of high organization paces of western nations to indigenous regions) is demonstrating these species-explicit introduction lines are obscuring. The determination depends on the trademark appearance of non-mending raised, scaling injuries that may ulcerate and turn out to be optionally contaminated with living beings, for example, Staphylococcus aureus, in somebody who has come back from an endemic zone. In asset restricted settings, fine-needle goal of the injury is corroborative with the distinguishing proof of the amastigote type of Leishmania. The highest quality level for analysis is PCR (polymerase chain response) causes DNA polymerase to make new strands of DNA identical to the layout given.