Novel pentablock copolymer-based nanoparticulate systems for sustained protein delivery

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Ophthalmic Drug Delivery

Background:

• Sustained protein delivery to the posterior eye segment remains a challenge.
• Biodegradable and biocompatible polymers are needed for advanced therapeutic formulations.

Purpose of the Study:

• To design, synthesize, and evaluate novel biodegradable pentablock (PB) copolymers for sustained protein delivery.
• To engineer PB copolymers for controlled release of protein therapeutics to the posterior eye.

Main Methods:

• Synthesis of PGA-PCL-PEG-PCL-PGA and PLA-PCL-PEG-PCL-PLA copolymers via ring-opening polymerization.
• Characterization using 1H-NMR, GPC, and XRD.
• In vitro evaluation of protein (IgG) encapsulation, loading, release kinetics, and secondary structure (CD spectroscopy).
• Cytotoxicity and biocompatibility assessment using ARPE-19 and RAW 264.7 cell lines.

Main Results:

• PB copolymers were successfully synthesized and characterized.
• Molecular weight and crystallinity significantly influenced formulation parameters like entrapment efficiency and drug loading.
• In vitro release studies demonstrated sustained protein release.
• CD spectroscopy confirmed the structural integrity of released IgG.
• Biocompatibility studies confirmed the safety of PB copolymers for ocular applications.

Conclusions:

• Novel pentablock copolymers are effective biomaterials for sustained protein delivery.
• These PB polymers address the unmet need for advanced ophthalmic drug formulations.
• Engineered PB copolymers hold significant potential for treating posterior segment eye diseases.