A biodegradable filament for controlled drug delivery

Area of Science:

• Biomaterials Science
• Ophthalmology
• Drug Delivery Systems

Background:

• Controlled drug delivery systems are crucial for sustained therapeutic effects.
• Biodegradable polymers offer advantages for localized drug release applications.
• Ophthalmic drug delivery faces challenges in achieving prolonged therapeutic concentrations.

Purpose of the Study:

• To develop and characterize biodegradable filaments for controlled release of dexamethasone or levofloxacin.
• To evaluate the in vitro and in vivo performance of these drug-eluting filaments.
• To assess the biocompatibility and degradation profile of the filaments in an animal model.

Main Methods:

• Biodegradable poly(lactide-co-glycolide) (PLGA) filaments were fabricated using wet-spinning with incorporated drugs (dexamethasone or levofloxacin) in dimethyl sulfoxide (DMSO).
• Compositional analysis determined drug loading and retention.
• In vitro drug release kinetics, thermal, and mechanical properties were assessed.
• Filaments were implanted in the conjunctiva of New Zealand white rabbits for in vivo tear concentration analysis and biocompatibility evaluation.

Main Results:

• Filaments achieved drug loadings up to 40% and drug retention greater than 40%.
• In vivo studies in rabbits showed that one filament (506-L1) maintained effective levofloxacin tear concentrations for 6 days.
• Filament failure in vivo occurred at 6-8 days, correlating with in vitro mechanical testing.

Conclusions:

• Biodegradable PLGA filaments are a viable platform for controlled ophthalmic drug delivery.
• The developed filaments demonstrate promising in vitro and in vivo drug release profiles.
• The filaments exhibit good biocompatibility and predictable degradation in the ocular environment.