A Technique to Generate a Novel Delivery Platform for a Delayed Burst Release of Molecules

Attach a syringe with a dispensing tube to a pump. The syringe contains a photoinitiator-polyester blend, a unique polymer mix.

Dispense the blend into a viscous aqueous solution of a cellulose-based polymer. This induces phase separation, forming a polymeric spherical structure called a polybubble.

Ultraviolet irradiation activates the photoinitiator, triggering the polymer to crosslink and form a shell surrounding the inner core.

Next, insert a needle to inject a viscous solution of fluorophore-tagged molecules into the polybubble core.

Irradiate again to restore the polybubble integrity. Freeze-dry to remove excess water and recover the polybubble.

To check the release profile, incubate the polybubble in a buffer.

Upon contact with an aqueous phase, the polymer shell undergoes erosion, thereby forming pores. Over time, these pores interconnect,  releasing the labeled molecules.

Regularly collect the supernatant and quantify the fluorescence intensities.

A sudden increase in fluorescence following extended incubation confirms the delayed burst release.

To fabricate the polybubbles, first, use a 1-milliliter transfer pipette to add 800 microliters of 10% CMC into a 0.92-milliliter