The structure, stability, and complex behavior of recombinant human gelatins

Area of Science:

• Biochemistry
• Materials Science
• Pharmaceutical Sciences

Background:

• Animal-derived gelatin is a common vaccine stabilizer but has limitations like heterogeneity and allergenicity.
• Recombinant human gelatins (rhGs) are developed as safer alternatives to animal gelatins.

Purpose of the Study:

• To characterize the structure and physical stability of four molecular weights of rhGs.
• To assess rhG behavior under varying temperature and pH conditions relevant to formulation.
• To investigate rhG complexation with heparin.

Main Methods:

• Spectroscopic techniques were used to analyze rhG structure and stability.
• Micro-aggregation was monitored across different pH values (5, 7, 8) and temperatures.
• Complexation of rhGs with heparin was studied under varying conditions.

Main Results:

• All four rhGs exhibited unpredictable micro-aggregation at various pH values.
• The 8.5 kDa rhG aggregated at pH 5; the 25 kDa rhG aggregated at pHs 5, 7, and 8.
• rhGs formed complexes with heparin via electrostatic and non-electrostatic interactions, with stability influenced by temperature and pH.

Conclusions:

• The solution properties and aggregation behavior of rhGs are complex and depend on molecular weight and environmental conditions.
• Understanding rhG stability and interactions is crucial for developing stable vaccine formulations.
• rhGs offer a promising alternative to animal gelatins, but their formulation behavior requires careful consideration.