Modular assembly of layer-by-layer capsules with tailored degradation profiles

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Layer-by-layer (LbL) assembly is a versatile technique for fabricating multilayered materials.
• Biodegradable and covalently stabilized capsules are desirable for drug delivery applications.
• Controlling capsule degradation kinetics is crucial for effective therapeutic delivery.

Purpose of the Study:

• To prepare biodegradable, covalently stabilized capsules with tunable degradation properties using LbL assembly.
• To investigate methods for controlling the degradation kinetics and location of capsule breakdown.
• To explore the potential of stratified hybrid capsules for tailored drug delivery vehicles.

Main Methods:

• Alternating assembly of poly(L-glutamic acid) modified with alkyne moieties (PGA(Alk)) and poly(N-vinyl pyrrolidone) (PVPON) on silica particles via hydrogen-bonding.
• Cross-linking of the assembled films with a bis-azide linker.
• Removal of the sacrificial template and PVPON at physiological pH to yield PGA(Alk) capsules.
• Incorporation of degradable cross-linkers and assembly of stratified hybrid capsules with nondegradable barrier layers.

Main Results:

• Successfully prepared one-component PGA(Alk) capsules with tunable degradation.
• Demonstrated control over capsule degradation kinetics by incorporating degradable cross-linkers.
• Fabricated stratified hybrid capsules with precisely controlled degradation profiles by adjusting barrier layer composition and position.
• Showcased the ability to tailor degradation kinetics through stratified LbL assembly.

Conclusions:

• The developed LbL approach enables the creation of biodegradable, covalently stabilized capsules with tunable degradation.
• Stratified hybrid capsules offer a promising platform for precise control over drug release kinetics.
• This methodology holds significant potential for the design of advanced, tailored drug-delivery systems.