Pulsatile and sustained peptides release from Zn(II) suspensions

Area of Science:

• Pharmacology
• Materials Science
• Biochemistry

Background:

• Solid-phase peptide release is crucial for drug delivery.
• Zinc(II)-peptide complexes offer a potential matrix for controlled peptide release.
• Understanding release dynamics is key to optimizing therapeutic efficacy.

Purpose of the Study:

• To investigate the in vitro release dynamics of thyroliberine, dalareline, and gonadoreline from solid Zn(II)-peptide complexes.
• To determine the influence of peptide molecular weight and Zn(II)-peptide complex properties on release kinetics.
• To characterize the pulsatile release patterns and release times.

Main Methods:

• In vitro observation of peptide release from solid, sparingly soluble Zn(II)-peptide complexes (50:1 molar ratio).
• Quantification of released peptides over time.
• Analysis of release profiles, including peak identification and release duration.

Main Results:

• Statistically significant differences in release rates were observed between thyroliberine/dalareline and gonadoreline.
• Pulsatile release was evident, with 6 peaks for dalareline, 5 for gonadoreline, and 4 for thyroliberine.
• Release times varied: thyroliberine (63 h ± 3.1), gonadoreline (12.0 h ± 1.0), and dalareline (26.5 h ± 2.3).

Conclusions:

• Peptide molecular weight and Zn(II)-peptide complex durability significantly impact release character and duration.
• Higher molecular weight peptides and more durable complexes result in more release peaks and longer release times.
• These findings provide insights into designing controlled peptide-release systems using Zn(II)-peptide complexes.