Modification of translationally controlled tumor protein-derived protein transduction domain for improved intranasal delivery of insulin

Abstract

Carrier peptides, termed protein transduction domains (PTDs), serve as provide promising vehicles for intranasal delivery of macromolecular drugs. A mutant PTD derived from human translationally controlled tumor protein (TCTP-PTD 13, MIIFRALISHKK) was reported to provide enhanced intranasal delivery of insulin. In this study, we tested whether its efficiency could be further improved by replacing amino acids in TCTP-PTD 13 or changing the amino acids in the carrier peptides from the l- to the d-form. We assessed the pharmacokinetics of PTD-mediated transmucosal delivery of insulin in normal rats and the activity of insulin in alloxan-induced diabetic rats. The safety/toxicity profile of the carrier peptides was evaluated based on the release of lactate dehydrogenase (LDH) in nasal wash fluid, body weight changes, and several biochemical parameters. Pharmacokinetic and pharmacodynamic studies showed that the l-form of a double substitution A6L, I8A (MIIFRLLASHKK), designated as l-TCTP-PTD 13M2 was the most effective carrier for intranasal insulin delivery. The relative bioavailability of insulin co-administered intranasally with l-TCTP-PTD 13M2 was 37.1% of the value obtained by the subcutaneous route, which was 1.68-fold higher than for insulin co-administered with l-TCTP-PTD 13. Moreover, co-administration of insulin plus l-TCTP-PTD 13M2 reduced blood glucose levels compared to levels in diabetic rats treated with insulin plus l-TCTP-PTD 13. There was no evidence of toxicity. These results suggest that the newly designed PTD is a useful carrier peptide for the intranasal delivery of drugs or biomolecules.

Modified translationally controlled tumor protein-derived protein transduction domain enhances nasal delivery of exendin-4 as shown with insulin

“…In a previous study, we constructed single mutant, A6L of TCTP-PTD 13 and double mutant, A6L, I8A of TCTP-PTD 13 and designated TCTP-PTD 13M1 and TCTP-PTD 13M2, respectively and demonstrated that TCTP-PTD 13M2 was found to be a useful vehicle for the delivery of insulin through the nasal membrane (Bae et al., 2018 ). In this study, we additionally designed a substitution S9Y of TCTP-PTD 13M2, called TCTP-PTD 13M3 ( Table 1 ), because of its higher hydrophobicity than TCTP-PTD 13M2, might be better at cargo delivery than others.…”

“…To evaluate the ability of TCTP-PTD analogs to increase the exendin-4 that delivered through the nasal administration, we performed PKs studies in normal rats. We studied using the simple mixtures and fixed their amounts based on our previous studies (Bae et al., 2018 ).…”

“…To evaluate the nasal pharmacokinetic (PK) profile of exendin-4 in rats, we simply mixed it with the PTD (1:2 molar ratio) (Bae et al., 2018 ). One hundred microliters of exendin-4 (200 µM) were mixed with 100 µL of PTD (400 µM) in 10 mM phosphate buffer (pH 6.4).…”

“…Attempts to overcome this have led to the use of absorption enhancers (Davis & Illum, 2003 ) and nanosystems (Battaglia et al., 2018 ), but proved toxic to the nasal mucosa. This led to the use of protein transduction domains (PTDs) for peptide/protein drug delivery by others (Khafagy El et al., 2010 ) and by our group (Bae & Lee, 2013 ; Bae et al., 2018 ).…”

“…We found that TCTP-PTD 13 (MIIFRALISHKK) exhibited increased ability to penetrate cell membrane with no cytotoxic side effects (Kim et al., 2011b ). Recently, we reported that the co-administration of mixtures of insulin with TCTP-PTD 13 or its mutant analogs efficiently delivered bioavailable insulin into the nasal mucosal membrane of both normal and diabetic rats without causing nasal membrane damage (Bae et al., 2018 ). In this study, we are reporting on the general applicability of this approach, employing another peptide, exendin-4, a 39 amino acids glucagon-like peptide-1 (GLP-1) anti-diabetic agent, and its intranasal delivery using a variety of modified TCTP-PTDs as vehicles for intranasal delivery.…”