Simple and Customizable Gelatin Nanoparticle Encapsulation System for Biomedical Applications

Objective: The double desolvation technique has been used to encapsulate small, hydrophilic drugs with protein affinity in gelatin nanoparticles for many years. Expanding the types of materials that can be encapsulated would allow the double desolvation method to be used for a wider range of biomedical applications, including biological delivery. Methods: Here, we use the double desolvation technique to encapsulate two different sizes of polystyrene beads as a first step toward encapsulating biologics like viruses and nucleic acids of similar size, shape, zeta potential, and functional groups in a new delivery system. Drug delivery systems that are easy to produce and customizable to different biomedical applications are in demand. With these parameters in mind, we created a simple gelatin nanoparticle encapsulation system with the potential for chemical modification for targeting purposes and encapsulation of different materials. Results: Matching the encapsulation material to the size and shape of the empty nanoparticles resulted in encapsulated nanoparticles of ideal narrow size distribution with stable storage parameters at room temperature over a 1-month period in distilled water. Additionally, the encapsulation system was shown to be most stable at pH 3-4 compared to other physiological pH ranges. Transmission electron microscopy verified the size ranges found using dynamic light scattering and revealed the inert material was encapsulated, partially encapsulated, and non-encapsulated nanoparticles in each formulation. Conclusion: This matched encapsulation material fabrication method may decrease the need for additional filtration after biologics are added and the encapsulation range would be ideal for sustained biologic release over time.