Poly(trehalose methacrylate) as an Excipient for Insulin Stabilization: Mechanism and Safety

Abstract

Insulin, the oldest U.S. Food and Drug Administration (FDA)-approved recombinant protein and a World Health Organization (WHO) essential medicine for treating diabetes globally, faces challenges due to its storage instability. One approach to stabilize insulin is the addition of poly­(trehalose methacrylate) (pTrMA) as an excipient. The polymer increases the stability of the peptide to heat and mechanical agitation and has a low viscosity suitable for injection and pumps. However, the safety and stabilizing mechanism of pTrMA is not yet known and is required to understand the potential suitability of pTrMA as an insulin excipient. Herein is reported the immune response, biodistribution, and insulin plasma lifetime in mice, as well as investigation into insulin stabilization. pTrMA alone or formulated with ovalbumin did not elicit an antibody response over 3 weeks in mice, and there was no observable cytokine production in response to pTrMA. Micropositron emission tomography/microcomputer tomography of 64Cu-labeled pTrMA showed excretion of 78–79% ID/cc within 24 h and minimal liver accumulation at 6–8% ID/cc when studied out to 120 h. Further, the plasma lifetime of insulin in mice was not altered by added pTrMA. Formulating insulin with 2 mol equiv of pTrMA improved the stability of insulin to standard storage conditions: 46 weeks at 4 °C yielded 87.0% intact insulin with pTrMA present as compared to 7.8% intact insulin without the polymer. The mechanism by which pTrMA-stabilized insulin was revealed to be a combination of inhibiting deamidation of amino acid residues and preventing fibrillation, followed by aggregation of inactive and immunogenic amyloids all without complexing insulin into its hexameric state, which could delay the onset of insulin activity. Based on the data reported here, we suggest that pTrMA stabilizes insulin as an excipient without adverse effects in vivo and is promising to investigate further for the safe formulation of insulin.

Peptide Inhibitors of Insulin Fibrillation: Current and Future Challenges

“…Among nanoparticles (NPs), those studied against insulin fibrillation include silicon NPs [ 62 ], ceria NPs [ 63 ], magnetite NPs [ 64 ], gold NPs [ 65 ], silver NPs [ 66 ], graphene oxide [ 67 ], organic NPs [ 68 ], carbon dots [ 69 , 70 , 71 ], and quantum dots [ 72 ]. Among molecules, there are glycopolymers [ 73 , 74 ], amphiphiles [ 75 ], aromatic molecules [ 76 ], polyphenols [ 6 , 77 , 78 ], vitamins [ 79 ], dyes [ 80 ], and various drugs [ 81 ]. The idea of the inhibition of amyloid aggregation, especially for insulin, is that molecules with hydrophobic functionalities can sequester the aggregation-prone regions of the target protein and inhibit its aggregation, while exposing more hydrophilic groups to assist with solubility.…”

The Promise and Potential of Metal–Organic Frameworks and Covalent Organic Frameworks in Vaccine Nanotechnology

“…We do note that MOFs have competition in this areamany systems, including sugars and polymers, likewise confer thermal stability by trapping proteins inside a glassy matrix . Sugar and polymer excipients use lyophilization or spray-drying to encapsulate proteins. , The slow drying of the two heterogeneous macromolecules makes phase separation of the commixture difficult to avoidthis phase separation results in small islands of protein aggregates within the amorphous structural interfaces .…”

Nano-Osmolyte Conjugation: Tailoring the Osmolyte-Protein Interactions at the Nanoscale

“…Effects of trehalose-based nanoparticles on the fibrillation of human insulin, lysozyme, and amyloid beta (Aβ) have been tested (Table ). ,, It has been found that the trehalose-conjugated nanoparticles can stabilize clinically important proteins in biological environments and can be used as safe formulations without adverse effects in vivo . Thus, it shows that the enhanced chaperone performance of sugar-conjugated nanoparticles extends the possibility for practical application (Table ).…”