Nanobody conjugated PLGA nanoparticles for active targeting of African Trypanosomiasis

Abstract

Targeted delivery of therapeutics is an alternative approach for the selective treatment of infectious diseases. The surface of African trypanosomes, the causative agents of African trypanosomiasis, is covered by a surface coat consisting of a single variant surface glycoprotein, termed VSG. This coat is recycled by endocytosis at a very high speed, making the trypanosome surface an excellent target for the delivery of trypanocidal drugs. Here, we report the design of a drug nanocarrier based on poly ethylen glycol (PEG) covalently attached (PEGylated) to poly(D,L-lactide-co-glycolide acid) (PLGA) to generate PEGylated PLGA nanoparticles. This nanocarrier was coupled to a single domain heavy chain antibody fragment (nanobody) that specifically recognizes the surface of the protozoan pathogen Trypanosoma brucei. Nanoparticles were loaded with pentamidine, the first-line drug for T. b. gambiense acute infection. An in vitro effectiveness assay showed a 7-fold decrease in the half-inhibitory concentration (IC50) of the formulation relative to free drug. Furthermore, in vivo therapy using a murine model of African trypanosomiasis demonstrated that the formulation cured all infected mice at a 10-fold lower dose than the minimal full curative dose of free pentamidine and 60% of mice at a 100-fold lower dose. This nanocarrier has been designed with components approved for use in humans and loaded with a drug that is currently in use to treat the disease. Moreover, this flexible nanobody-based system can be adapted to load any compound, opening a range of new potential therapies with application to other diseases.

Nanobodies As Tools to Understand, Diagnose, and Treat African Trypanosomiasis

“…Hereby, nanoparticles loaded with pentamidine [i.e., drug used for treating the early disease stage, before central nervous system involvement (87), as the second-line option to suramin] were coupled to Nb-33. This targeted drug-bullet allowed decreasing the half-inhibitory concentration (IC50) 7-fold compared to free drug in vitro and cured all mice at a 10-fold lower dose than the minimal full curative dose of free pentamidine (88–90). Moreover, recently an improved version of this nanocarrier allowed reducing the curative dose 100-fold and circumvented drug resistance that is due to mutations in aquaglyceroporin 2 (i.e., the surface channel protein that mediates pentamidine uptake in T. brucei ) (29, 91, 92).…”

Vitamin E-Oligo(methyl diglycol l-glutamate) as a Biocompatible and Functional Surfactant for Facile Preparation of Active Tumor-Targeting PLGA Nanoparticles

“…These robust multifunctional PLGA NPs could have a great potential in active tumor-targeting delivery of various drugs and proteins. [41][42][43] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 following HA coating have an excellent stability. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 16 drug concentrations of 0.01-10 µg/mL ( Figure 3B)…”

Use of camel single-domain antibodies for the diagnosis and treatment of zoonotic diseases

“…Another approach is to couple pentamidine, a first-line antitrypanosomiasis, to VHH An33 to effectively target the drug to the parasite. In vivo, a ten-fold lower dose than the minimal full curative dose of free pentamidin incorporated into this conjugate cured all infected mice, wheras a 100-fold lower dose cured 60% of them [62]. Parasite development in the tsetse fly and subsequent spread of the parasite can be controlled through the expression of trypanolytic VHHs in genetically modified tsetse fly symbionts [63].…”