Precise and tunable time-controlled drug release system using layer-by-layer films as erodible coatings

Area of Science:

• Materials Science
• Biomedical Engineering
• Drug Delivery

Background:

• Conventional drug carriers often lack precise control over drug release timing.
• Erodible coatings for time-controlled release are challenging due to complex erosion behaviors and unpredictable lag times.

Purpose of the Study:

• To develop a novel coating system for predictable and tunable time-controlled drug release.
• To investigate the potential of dynamic layer-by-layer films as ideal erodible coatings.

Main Methods:

• Fabrication of dynamic layer-by-layer films using poly(ethylene glycol)/tannic acid (PEG/TA) via hydrogen bonding.
• Coating bimodal mesoporous silica (BMS) spheres with PEG/TA films of varying thicknesses.
• In vitro and in vivo evaluation of drug release profiles.

Main Results:

• PEG/TA films demonstrated clear, simple erosion mechanisms and constant disintegration rates.
• BSA release from BMS spheres was successfully deferred by PEG/TA coatings.
• Tunable lag times were achieved by adjusting PEG/TA film thickness, enabling multiple pulse release.
• Similar controlled release patterns were observed in vivo.

Conclusions:

• Dynamic layer-by-layer PEG/TA films offer a predictable and tunable approach for achieving time-controlled drug release.
• This method simplifies the design and optimization of drug delivery systems requiring specific release profiles.
• The findings suggest significant potential for in vivo applications in targeted and pulsatile drug delivery.