Compact Polyelectrolyte Complexes of Poly(l-Lysine) and Anionic Polysaccharides

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biotechnology

Background:

• Compact polyelectrolyte complexes (CoPECs) mimic biological tissues with properties like self-healing.
• Most CoPECs use synthetic polymers; biopolymer-based examples are scarce.

Purpose of the Study:

• Investigate CoPECs formed entirely from biopolymers: poly(l-lysine) (PLL) with sodium hyaluronate (HA) and alginate (Alg).
• Determine optimal conditions for CoPEC formation, including salt concentration and charge ratios.
• Evaluate molecule loading and release kinetics within the developed CoPECs.

Main Methods:

• Preparation of PLL-HA and PLL-Alg CoPECs under varying conditions (NaBr concentration, cation:anion ratios).
• Characterization of CoPEC viscoelasticity and swelling behavior in different osmotic media.
• Quantification of molecule loading efficiency and release profiles for various compounds (paracetamol, crystal violet, diclofenac).

Main Results:

• Optimal formation of viscoelastic PLL-HA CoPECs achieved at a 2:1 cation:anion ratio and 0.25 M NaBr.
• PLL-Alg CoPECs favored a 1:1 ratio and 1.0 M NaBr.
• CoPECs exhibited osmotic responses, swelling in hypertonic and contracting in hypotonic media.
• PLL-HA (2:1) CoPECs showed higher loading of anionic molecules and varied release times (2-48 hours).

Conclusions:

• Biopolymer-based CoPECs can be successfully synthesized using PLL with HA or Alg.
• The properties and performance of CoPECs are tunable via polymer choice and preparation conditions.
• These biopolymer CoPECs demonstrate potential as matrices for controlled molecule delivery.