Designing pullulan phosphates with tunable structure-property relationships via a multicomponent reaction system for...

Area of Science:

• Biomaterials Science
• Polymer Chemistry

Background:

• Phosphorylated polysaccharides are promising biodegradable and biocompatible materials.
• Controlled phosphorylation of pullulan and its structure-property relationships require further investigation for biomedical applications.

Purpose of the Study:

• To explore controlled phosphorylation of pullulan using a multicomponent organic system.
• To investigate the structure-property relationships of the resulting phosphorylated pullulan derivatives.
• To assess the potential of these derivatives in biomedical applications.

Main Methods:

• Pullulan was phosphorylated in a multicomponent organic system (tributyl phosphate, orthophosphoric acid, phosphorus pentoxide, chloroform).
• Characterization involved FTIR, NMR (1H/13C/31P), GPC, SEM, rheology, and TGA/DSC.
• Swelling, viscoelastic properties, thermal degradation, enzymatic degradation, and in vitro biocompatibility (hemolysis, fibroblast viability) were evaluated.

Main Results:

• Phosphorylated pullulan derivatives with 1.2-19.9 wt% phosphorus were synthesized, exhibiting water solubility and hydrogel formation.
• Increasing phosphorylation tuned swelling capacity (1.6-370 g/g) and viscoelasticity (storage moduli up to 40 kPa).
• Thermal degradation onset shifted to 180-240 °C, and residual mass increased to 69% at 600 °C.
• Enzymatic degradation varied with phosphorus content and crosslinking, with hydrogels showing slower degradation.
• Derivatives demonstrated excellent biocompatibility, with <2% hemolysis and ≥80% fibroblast viability at 2 mg/mL.

Conclusions:

• Multicomponent phosphorylation offers a method to create pullulan derivatives with tunable composition, mechanics, and degradation.
• These phosphorylated pullulan derivatives exhibit promising in vitro biocompatibility.
• The tunable properties highlight their potential for advanced biomedical applications such as drug delivery, wound dressings, and soft tissue engineering.